MXPA97009925A - Reliable eliminable films - Google Patents

Abstract

The present invention relates to a thermoset resin film, thin to be subjected to a relief removal process that eliminates a relief of printed circuit pattern grooved thereon with minimal loss of accuracy of the relief of relief of the grooved pattern, in wherein the pattern and the groove can be cured to produce a thermosetting resin film to eventually generate a printed board. The thermoformable film can be formed without the need to obstruct flow at the edges of the resin film. The resin is non-conductive and the film is sufficiently uniform in thickness in order to provide consistent compliance capacity by heat between the film space. The film has low flow over a wide range of temperature, so that it does not flow uncontrollably while undergoing curing conditions. The film gels or reaches properties similar to a state of gelation on conditions that carry curing, which satisfy commercial conditions

Description

ELIMINABLE RELEASE FILMS DESCRIPTION OF THE INVENTION This application is related to the requests of the United States co-pending Series No. 08 / 474,929 (Attorney File No. 4236) Serial No. 08 / 474,439 (Attorney's File No. 4237 Serial No. 08/483, (File of Attorney No. 4238) each of which was deposited on the date given herein. An isotropic film of thin thermosetting resin which is suitable for being subjected to a relief removal procedure which imparts a printed circuit pattern thereon with a minimal loss of relief accuracy to eventually generate a printed board or tool for manufacture printed boards. The term "printed board" ("PB") is understood to be a general term for printed wiring or fully printed circuit wiring configurations. This includes rigid or flexible boards (organic or ceramic) and individual, double, and multi-layered printed boards. A "printed wiring board (" PWB ")" is a subset of the PB. This is a board with connections only printed point to point. A "printed circuit board" is another subset of the PB.

This is a board with printed components as well as point-to-point connections. In the following description, the reference to PB is proposed to cover PWB and PCB.

A typical PB is a flat board that maintains chips and other electronic components. The board is made of thermo raguable resin laminate reinforced with fiberglass. This interconnects components via conductive metal paths. Typical resins used in the manufacture of PB are epoxy resins of the brominated bisphenol A type, bis-maleimide resins and polyimide resins. The resin is typically impregnated in a glass fiber cloth and compression molding. The impregnated fabric (the "prepreg") is laminated into a multiple structure, which contains as many as four or more folds. Such a structure provides a high ratio of fiberglass to the resin. The conventional printed circuit is an engraved circuit. This is done by a chemical imaging process. A copper foil laminate with a photocurable substance is covered. U.V light is incised through a negative image of the trajectories of the circuit on the photocurable substance, hardening the areas that will remain after the engraving. The part is then treated to eliminate the unhardened areas of the photoresist. When it is passed through an acid bath (for example, ferric chloride solution), the exposed copper is etched. The hardened areas of the photocurable substance are separated. A copper oxide treatment is applied to achieve the proper bonding to the next layer of laminate or to the top layer, a layer of solder mask is applied. A similar process creates micro-miniaturized circuits on a chip. In particular, the electrical laminates used in PB comprise thermosetting resin as immediately described below, cloth or continuous filament fiber impregnated fiber systems which are combined with copper metal foils and pressed in a multiple aperture press to form laminates. The laminates have either one or both sides metallized with copper. The resin matrix reinforcement systems are in the range of moderately inexpensive materials, such as phenolic / paper and polyester / glass laminates for general purpose epoxy / glass known as FR-4 for high performance systems (expensive) based a bismaleimide-triazine (BT) / glass or polyimide (Pl) / glass. Most laminates are pressed / cured in multi-aperture presses. At least one company manufactures a hybrid epoxy / polyester copper laminate in a continuous operation.

These different electric laminates are thermally distinguishable by comparing their respective Tg: Tg, ° C Phenolic / Paper 90 Polyester / Glass «100 Epoxy / Glass« 125 BT / Glass 225 Pl / Glass 260 The hybrids of this matrices of previous resins are coated on glass and pressed / cured in laminates with intermediate Tg: tg, ° c Epoxy / BT-glass 160-200 Epoxy / PI-glass 200-260 The FR-4 varnish which covers the glass is a complex mixture of epoxy resins, catalyst, amine accelerator and solvents. The prepreg reinforced with broadening epoxy resin glass catalyzed by dicyandiamide (dici) with an amine accelerator is "graduated B" inside dry prepreg sheets with a flow ranging from 8 to 30%. The flow values help to select the appropriate pressure / cure cycle in the manufacture of multiple copper metal laminates (FR-4). Typically, these multiple prepreg are combined with copper metal sheets and pressed into a multi-aperture press at as high as 1000 psi, 350 ° F (176.7 ° C), and requires 30 to 60 minutes to complete the cure. An outline of the total operation in Figure 3 is illustrated. Any excess resin burr that must be cut is developed on the laminate sides and results in a variability of the laminate. Caul plates, used to press the laminates, periodically build epoxy residues that cause laminate imperfections and non-smooth surfaces. After many pressures, Caul plates must be cleaned by a highly expensive chemical or grinding / polishing operation. A maximum level of cure of the resin is essential to finalize the mechanical properties and the dimensional capacity to press free laminates. If not properly cured, problems are amplified during the initial processing steps leading to a PB. The partial or incompletely cured laminate causes diffusion of the resin (flow) during the drilling operation (alignment and assembly of laminates in multilayer boards). The resin flows and is deposited on the drill hole causing misalignment and possible rejection of the finished PB during the final test. The comparison of the mechanical and electrical properties of phenolic and epoxy / glass paper (FR-4) clearly identifies FR-4 as the superior material.

On a cost-based basis, the FR-4 board is the predominant PB material in the United States. With more preassembled devices (surface mount devices) and significant deviation to multi-layered boards, the thermal / mechanical limits of FR-4 are being exceeded by large thermal incursions caused by novel assembly technology. A significant problem associated with double-sided and multi-layered (MLB) boards is the coating through a hole (PTH). The process of forming the copper deposit through the hole involves making holes through each of the laminated layers, preparing the hole for the coating, sensitizing the hole with non-electrolytic copper, and finally electrodepositing with copper to the desired thickness. Studies have shown that PTH can survive only "few thermal cycles" (Z-axis expansion of FR-4) before fatigue / copper failure occurs. A company reports 220 ppm / ° C for the Z axis of FR-4 by the midpoint of TMA between 50 ° C and 250 ° C. The mismatch of the coefficient of thermal expansion ("CTE mismatch") between the copper "cylinder" PTH and FR-4 results in cracked terminal areas, cylinders and / or delamination of the layer. This point is described by Harper and Miller, Electronic Packaging, Microelectronics, and Interconnection Dictionary, McGraw-Hill, Inc., New York, NY, 1993, in its definition of "Axis Z": "(1) Address through the The thickness of a substrate is particularly important for laminates of printed wiring boards, since the thermal expansion in the ee Z is much higher than in the ee XY (sic.) This is because the resin in the laminate controls the thermal expansion of the Z axis, while the fabric in the laminate controls the thermal expansion of the XY axis.The reams have much larger thermal expansions than do the fabrics. (2) The directional direction to the fibers in a reinforced laminate. Spun fiber - to say, through the laminate thickness.The thermal expansion is much higher on the Z axis, since this expansion is more controlled by the ream in the laminate. " There are a variety of improvements regarding PB manufacturing that are sought after by the industry. One is in the area of cost reduction. Another is related to the reduction in capital investment of a production line to produce PB. A third improvement involves the environmental problems that plague the current processes to manufacture PB. A fourth improvement is a circuit density greater than that which requires thinner lines and spaces. For example, the processes of photoimage and engraving involve expensive capital equipment and dangerous chemicals. A coating of photohardening substance is required, followed by a UV exposure machine, followed by a rinse that generates contaminated wastewater. This is followed by an engraving line that usually consists of 2 to 5 etching tanks and 10 to 15 rinse tanks, all of which generate toxic waste. The essence of a PB is to provide the trajectories of the circuit that carry the electrical impulses from one point to another. The pulses flow through on / off switches, called transistors located on chips, which open or close when activated electrically. The current flow through one switch effects the opening or closing of another and successively. The small groupings of the transistors form logic gates, which are the building blocks behind all this magic, and a specific combination of logic gates makes a circuit. Currently, the chip is typically an integrated circuit. Chips are squares or rectangles that measure approximately 1/16 to 5/8 of an inch on one side. They are approximately 1/30 of an inch thick, although only the top 1/1000 of an inch holds the current circuits. The chips contain from a few dozens to several million electronic components (transistors, resistors, etc.). The terms chip, integrated circuit and microelectronic are synonymous. Chips are generally characterized by their function. The chips depend on the individual glass silicon wafers on which an electrical circuit is provided. The layers of these plates can be used to define the function of the chip. The crystal is then placed in a conductive structure, with extended copper and nickel alloy conductors. The structure is packaged (encapsulated) with an epoxy molding compound such as an epoxy cresol novolac resin ("ECN"). The covered chip is adhesively bonded to the PB with an epoxy resin adhesive that requires heat to cure.

The chip conductors are then linked, for example, by welding, to the metallic circuitry of the PB. The current PB technology is reaching its limits in terms of how fine circuit lines can be manufactured economically, while decreasing the sizes of portable electronic equipment will demand even more fine lines. It will be recognized that a byproduct of a miniatupzation of a PB and a chip is speed. The shorter the distance an impulse travels, the faster it will arrive. The larger minituarization allows greater availability of the area for more circuitry. In this way, allowing more functions to be added to the circuit. The smaller the components that build the transistor, the faster the transistor will switch. The same effect holds the truth with respect to a PB. The switch times of the transistors are measured in billions and trillions of a second. In fact, a Josephson junction transistor is suitable for switching in 50 cadrillones of a second. In this way there is a tremendous impetus to reduce the size of chips and PB, and in the case of PB, reduce the distance between functions interconnected between the PB. George D. Gregoire, Dimensional Circuits Corp., San Diego, CA, 92126 in a document entitled "Fine-line 'Grooved' Circuitry - A New PB Process for SMT," describes an evaluation of its process to manufacture and employ PB in common an application of surface mount technology (SMT), which is in part the technology described in U.S. Patent Nos. 4,912,844 and 5,334,279. [Surface mounted is a circuit board packing technique in which the conductors (struts) on the chips and components are welded on top of the board, not through it. As a result, the boards can be smaller and built faster]. From this analysis, Mr. Gregoire defines the so-called "improved circuit fabrication and trace geometry process for PBs containing" grooved traces "or" conventional circuitry. "The manufacturing process employs a hot printing process to form circuits According to the author, the main parts of the process include: * The molding is done with a lamination press with laminated materials of ordinary panel size (for example, epoxy-glass, polyimide, etc.) in a prepreg form.; * The following stages of traditional PB production are omitted: * photo-print production (film) * protective layer deposited on the dry film * film registration to PB (characteristic and mold.o) * image production * revealed, and * possibly , the protective layer welded in its entirety. A small amount of common engraved protective layer is used in a "self-location", leveled form, no registration steps are required. The protective layer is set to be retained and protected in the grooves, below the surface, during engraving.

To define the meaning of this technology for users, Gregoire states that this dramatically improves the welding performances during the mounting of fine slot surface. It is established that notched circuits provide performance improvements in the self-location feature during assembly as notches or channels allow SMT IC conductors to self-authenticate. The self-location feature provides improvements in performance and quality (for example, much greater drag resistance). The deep funnel shaping channels, wide fully wick and filled with solder, producing automatic allocation for tilt and out-of-planeness problems that arrive with a high conductor count, thin slot IC. A significant deficiency of the molding stage of this process is the use of thermosetting resins in the prepreg form, which means that the prepreg sheet contains a fiberglass cloth to reinforce the epoxy resin. Some specific resins mentioned are epoxy-glass and polyimide, without specifying the fiber. In the latter case, it is assumed that fiber is fiberglass. This requires hot printing on a non-elastic fiber mass that restricts resin flow and resists well-defined relief of relief. On the other hand, a resin-glass prepreg creates an anisotropic substrate that creates CTE misalignments for any copper layer deposited on it, due to the irregularity of the surface of that material. As indicated above, this results in "cracked terminal areas, cylinders and / or delamination of the layer", clearly indicating why such a substrate is not favored by Gregoire. Parker, U.S. No. 4,912,844 discloses drilling an optionally planar substance with a drilling machine that can be heated to impart notches and cavities in the surface. The punch may have a laminated sheet disposed thereon such that it is transferred to the substrate and in the notches and cavities in the substrate. The portions of the metal foil on the surface of the substrate can be removed by printed circuit techniques or by machining or laser techniques, such that only the portions of the metal foil in the grooves and cavities remain. Figures 1-8 of the patent list alternative steps for producing a printed circuit. They are listed in the following table: Figure 5 Figure 6 Figure 7 Figure 8 Arranged a Mark or Cut by Pressing with a Press the sheet on a laser surface the flat surface perforation of a metal around flat one to create portions drilling the hole for high drills Shaping the sheet to elevated portions of the perforation the perforator Cover the surface Heat the perforator image of notches and a flat temperature with a material at a desired temperature high photo curable in a high on the mask of the pattern that perforation corresponds to the desired pattern of notches and holes in the substrate Engrave the foto As an alternative Eliminate ais portions As an alternative or exposed image or as a stage of drilling without it as a notched stage and additional heat the additional material heat the holes on the substrate photo-hardened substrate notch Deposit the portion Apply the perforation Endurecer the ma terial Press the sheet on gravel of the mask to a surface of the photohardened on and within the to fill the substrate to form substrate surface to produce holes and notches the notches and notches and holes in the mask holes in the substrate substrate Remove the mask Remove the Heat the perforator Remove the blade from the drilling rig at a surface temperature of the raised substrate substrate while retaining the blade in notches and holes in the substrate Heat the perforator Arrange the As an alternative or Arrange them at a temperature components such as a stage electrical components in the additional heat the electrical in the holes in the substrate holes in the substrate substrate As an alternative or Apply a material Apply the drill to Apply a material such as a conductive stage an additional conductor surface electrically heating said substrate to electrically form such a substrate as a weld to the notches and as a weld to the notches in the holes in the substrate the notches in the cross-section of the cross-section establish electrical continuity electrical continuity with components with electric electrical components Apply perforation to Remove the one surface of the drilling machine from the substrate to form substrate the notches and holes in the substrate Remove the Arrange the drills from the electric substrate components In the holes in the substrate, arrange the Apply a material electrical conductor components in the electrically such holes in the substrate as a weld to the notches in the sastrato to establish electrical continuity with the electrical components Apply an electrically conductive matepal such as a weld to the notches in the sastrato to establish electrical continuity with the electrical components. An advantage of the method of PB of U.S. Patent 4,912,844 is the exploitation of notches and cavities in the board to provide the printed circuit. This allows creating the necessary surface area to create low electrical resistance in the wiring placed in the notches and associated with the cavities. Note that the depth of the notches is preferably at least as large as the width of the notches, and since the welder can fill the notches, the widths of the notches can be made very small whites still retaining relatively low electrical resistance. In a number of examples, such as in column 4, lines 9-19, column 5, lines 4-8, lines 9-16, lines 18-19, the patent uses heating of the substrate to deform using temperatures up to temperature of fusion of the substrate. This shows that the substrate must be heated above a glass transition temperature in order to achieve the flow. On the other hand, the patent also states that the PB can be made of a ceramic or epoxy-glass material. In addition, the patent states that the substrate can also be manufactured from thermoplastic or high temperature thermoplastic materials without specifying that they may have their properties. The patent lacks the details of how the metal foil is bonded to the thermoplastic or thermoplastic substrate and how to avoid a CTE mismatch, as characterized above. For example, a metal foil will not bind strongly to a thermoplastic substrate, even if the substrate is fused in contact with the foil; an adhesive is required to effect reasonable bonding of the sheet to the thermoplastic substrate. This seems to be recognized in the recently issued United States Patent Gregoire 5,390,412 which specifies the use of an "adhesion-promoting coating" which involves forming a "dentritic oxide coating" by bathing in a "water-based bath" with the purpose of joining an electrodeposited copper layer to a dielectric substrate. The United States Patent of Gregoire, 5,334,279, relates to an impression of PB to produce three-dimensional PBs having notches with metal fitters laminated or tightly bonded therein. The printing of the circuit board comprises a metallized male molding substrate having a plurality of notches forming the projections. The metallized molding substrate is made from a predecessor or paternal female master tool. The patent articulates a three-dimensional PB that employs a highly deflective plastic by heat, without defining the plastic and grooves or grooves molded on the surface of the substrate to receive the fine slot, closely spaced apart conductors, of an integrated circuit. The United States Patent of Gregoire, 5,351,393 is another patent in this area. The Gregoire and Parker patents, all assigned to Dimensional Circuits Corp., aimed at technology to simplify the fabrication of PB, demonstrate the complexity of fabricating impressions and fabricating PB of the prints. One of the reasons for such complexity is that the construction materials that are used for stamping and for printed wire boards are not defined or are inappropriately designed for a simple and effective PB construction that avoids CTE misalignments and for construct impressions that can be used in the shaping of plastics and resins in printed wire board substrate whether they contain or do not contain notches and cavities. The PB manufacturing technique is restricted by the processes and materials from which it is manufactured. Intensive work techniques such as spreading, silk screened, masking, etching, and the like, raise PB costs. There is a need for a cost effective and simple method to manufacture PB that has the ability to minimize the required use of labor intensive techniques. This invention relates to a thin isotropic thermoshable resin film which is suitable for being subjected to a relief removal process imparting a printed circuit pattern thereon. The thin isotropic thermoshable resin film avoids the aforementioned CTE deficiencies of the anisotropic fabric prepreg. This can be done with a minimum loss of relief elimination accuracy to eventually generate a printed circuit board that lacks the CTE mismatch or to form a useful tool for carrying out the relief removal procedure. The thin thermosettable resin film has the ability to be precision molded with tool at a relatively low temperature, such temperatures as low as room temperature (approximately 23.5 ° C) with superior duplication of the pattern.

In particular, the invention relates to a thin thermosetting resin film which is suitable for being subjected to a relief removal procedure which removes a relief of a printed circuit pattern grooved thereon with a minimum loss of accuracy of elimination of reliefs of the grooved pattern, in which the pattern and grooving can be cured to produce a thermosetting resin film that can be used to eventually generate '-'B. In addition, the thin thermosetting resin film is suitable to be subjected to flow in the grooves and cavities of a female tool, as defined above, whereby a male replication of the female tool is formed, subjecting the resin to high enough temperatures. , enough to cure the resin and fix a surface of the same to duplicate a male image of the female surface. In this way, the film of the invention is converted into a male tool by manufacturing a PB by printing another film having the same, or similar composition. The invention also contemplates a thin isotropic film of a thermosetting resin containing in situ expandable thermoplastic particles containing an essentially uniform density and thickness between the film space. In this mode, the pressure accumulated inside the film during curing causes the film to expand. The invention contemplates placing such a film in contact with an embossing pattern containing a replication printed circuit pattern and heating the film at a temperature which causes the expandable thermoplastic particles in situ to expand on the • surface of the stamp. of relief removal to generate- a pattern of relief removal-- the expanded particle. The term "isot --- peak" means, in the context of this invention, a material that possesses essentially the same electrical and physical properties in all directions therethrough, (eg, x, y and z). This may be in contrast to the prepreg reinforced with fabric. Such prepreg are anisotropic. They exhibit several differences in properties between the directions x, y and z. In the case of this invention, the films do not exhibit differences in electrical and physical properties by more than 20% in any direction. The thermosettable resin film of the invention has the following characteristics: a) it is designed for forming by processes such as printing, compression molding, transfer molding, injection molding and the like; b) the resin is non-conductive, which means that the resin can be used as a dielectric substrate; c) this is an isotropic thin film which is sufficiently thick in thickness to provide a consistent and essentially uniform heat shaping capacity between the total film, and the thickness must be sufficient to accept the shaping imposed by the forming process; d) the resin can be compression molded or stamped without the need to obstruct flow at the edges of the resin film; e) the film possesses low flow over a wide range of temperature, such that it does not flow out of control while undergoing the curing conditions, and when placed under pressure, only the portions that are superimposed on a notch or cavity in the case of a female mold, or on a protrusion in the case of a male mold, will cause it to flow due to the pressure imposed on the film; and f) film gels achieve properties similar to a state of gelation, under conditions that lead to curing, which satisfy commercial conditions. In a preferred embodiment, the invention relates to an essentially non-conductive isotropic thermosetting resin film that is mouldable without edge flow obstructions, which contains, in its main ingredients, (i) a thermosetting resin advancing in molecular weight without form a significant volatile by-product; and (ii) a flow control component. The resin film has a) a uniform area thickness in the range of about 1 to about 250 mil (about 0.00254 cm to about 0.635 cm) as calculated from the weight of the resin film for a given area. b) with minimum and maximum thickness that does not exceed the deviation factor indicated in Table A. Table A Range in mils Deviation Factor 1 to 5 ± 1 thousand (± 0.00254 cm) 5 to 10 ± 2 mils (± 0.00508 cm) 10 to 250 ± 20% c) low flow over a wide temperature range; d) the ability to cure, gel, or near gelation, at temperatures from about 20 ° C to about 250 ° C, in less than about 7 days and more than 1 second; e) a low dielectric constant in the thermoformable state. In a further improvement of the invention, the essentially conductive non-conductive thermosetting resin film employs as the flow control agent a diverse group of materials, such as: i) one or more electronic grade fillers; ii) a thermoplastic resin that is soluble and partially soluble in the thermosetting resin; iii) an elastomer-type polymer that provides discrete elastomer phases, (secondary phase) in the thermosetting resin matrix; iv) a thixotropic; and v) a mixture of two or more of i), ii), iii) and iv). In another embodiment of the invention, the essentially non-conductive, formable, thermosettable resin film is depositable metal and adheres to a conductive metal film. In particular, the film is metal depositable and adhesive-bondable to the metal foil which can be used in the manufacture of a printing surface or to create a conductive path over the printed and cured resin film. The metal sheet that is laminated to the thin resin film is a relatively thin sheet of essentially uniform thickness as characterized by ANSI / IPC-MF-150f, S 3.4.3, adopted on October 4, 1992, entitled: "Metal Foil for Ppnted Wiring Applications, "published by the Institute for Interconnecting and Packaging Electronic Circuits, 7380 N. Lincoln Avenue, Lincolnwood, IL 60646. The metal sheet may have a thickness between about 0.1 thousand to about 20 thousand; variant ± 10 percent for deposited leaves and ± 5 percent for forged metallic sheets. Suitable forms of the metal foil are electrodeposited or forged forms. The metal foil can be manufactured from a variety of conductive metals and metal alloys, such as aluminum, copper, chromium, gold, silver, magnesium, nickel, bronze, zinc, and the like. The preferred metal foil metals are aluminum, copper and nickel. Copper grade metal sheets are characterized by ANSI / IPC-MF-150F, to S 1.2.4.1. The metal sheet can be a separately formed sheet that is adhesively bonded to the thin resin film or the metal sheet can be formed as a ho-to-bonded to the thin ream film by a metal deposition technique. The deposition of metal can be effected by deposition of electrolytic metal, by metallization by metal ion pump, vacuum deposition, and the like. BRIEF DESCRIPTION OF THE DRAWINGS Figures IA, IB, IC, ID, 1E and 1F are schematic side views illustrating the use of the film of the invention. Figure 2 is a schematic side view for a line for continuous production of the film of the invention. Figure 3 is a schematic view of a prior art system for manufacturing PB. There are many commercial thermosetting resin systems that can be used to produce a thin, flexible, flexible thermosetting resin film. For example, certain such films are used in Synspand® and Syncore®, expanded or expandable films that are sold by The Dexter Corporation. However, another special subset of such a resin system is a thin isotropic thermoshable resin film which is suitable for being subjected to a relief removal procedure which prints a printed circuit pattern thereon, without creating mismatches of the expansion coefficient thermal ("CTE") and between the copper deposited in it that can result in cracks in notches, plugs, attenuators, etc. Such resin film must be able to effect sufficient precision of relief of reliefs to generate eventually a PB or to form a useful tool to carry out the process of elimination of reliefs that leads to the PB. The thin thermosetting resin film must have the ability to be accurately removed from the reliefs, for example, stamping, with a tool at a relatively low temperature, such as temperatures as low as room temperature (approximately 23.5 ° C) with superior duplication of the pattern. It is particularly desirable that the thin thermosettable resin film be suitable for a stamping process that removes the relief of a printed circuit pattern grooved thereon with minimal loss of relief accuracy of the grooved pattern. The film must be able to retain the pattern removed from relief and groove through a cure cycle without flowing out of the pattern, to produce a thermosetting resin film (eg, cured) that is employable to manufacture a printed circuit board . On the other hand, the thin thermosettable resin film can be subjected to flow within the female notches and cavities, as defined above, to form a male replication of the female tool. Or the film can be shaped and stamped with a tool, subjecting the resin to temperatures high enough to fix the resin (for example, by gelation, incipient gelation ("close to gelation") or cure) while in contact with the tool, so that a surface of the same is fixed to replicate the male or female image of the female or male surface, as the case may be. In this way, the film of the invention can be converted to a male or female tool, by fabricating a PB by removing the relief of another film having the same composition or the like, or the film can be used as a PB substrate. The elements of the film of thermosetting resin essentially non-conductive, is that it is conformable. This has a thin uniform thickness. It contains a thermosetting resin that advances to a cured state without forming a significant volatile byproduct that will affect the quality of the cured film. It contains one or more flow control components that allow the film to be molded without edge flow obstructions, one provides low film flux over a wide temperature range and retains a relief image during relief removal and through the healing of the movie. The film proceeds, under conditions that lead to the curing of the thermosetting resin to a state of gelation (see method IPC-TM-650 2.3.18) or a condition that gives physical properties similar to the state of gelation (for example, incipient gelation) at temperatures as low as about 20 ° C to about 250 ° C, in at least about 7 days and more than 1 second. Last, but not least, the film exhibits a low dielectric constant (for example, it has the ability to resist the formation of an electric field within it) consistent with the requirements of a PB. In another embodiment of the invention, the thermoformable, essentially non-conductive, moldable resin film is depositable metal and adheres to a conductive metal film. In particular, the film is depositable metal and adhesively bonds to the metal foil that can be used in the manufacture of a printing surface or to create a conductive path over the printed and cured resin film. The Texmobleable Resin The typical thermosetting resin is a graded resin A. In some cases, it may be desirable to use a graded resin B, but in the typical example, such is made in combination with a graded resin A. Such graded resin B will affect the viscosity of the resin formulation but typically do not depend on this to achieve the level of thickness for most of the effective operations of the invention. Epoxy systems are cured in the range of 150 ° -400 ° F (65.5 ° C-204.4 ° C) are common matrix resins for making thin film thermosetting resin products including the products of this invention. It can also be used bis-maleimide matrix resin (BMI), phenolic resins, polyester resins, PMR-15, polyimide, cyanate ester and acetylene-terminated resins. The matrix resins most widely used are epoxy resins, and a wide variety is suitable for use in the practice of this invention. Illustrative of such epoxy resins are the following: Resins through the edges.

The epoxy resins can be modified up to 95 percent by weight including in the resin formulation bis-aryl cyanate esters, such as those of the formula: wherein X is a bisphenol bond and R 1, 2, 3 and 4 are ring substituents such as hydrogen, alkyl, aryl and the like. Illustrative compounds are: Another preferred resin is one which is entirely the reaction product of one or more of the bis-aryl cyanate esters.

Catalysts and Hardeners Epoxy resin systems contain epoxy curing agents to form solid, non-fusionable products. For this purpose, epoxy curing agents that are acidic, neutral or alkaline can be used. Examples include, among others, hardeners of amines, phenols, acid anhydrides, polyamides and Lewis acids and bases. Desirably, the epoxy resins of the invention are combined with hardeners which cure the resins to a thermoformed condition. Preferred hardeners are amine compounds, ranging from dicyandiamide to ureas, to aliphatic and aromatic amines. The aromatic amines encompassed by the formula are preferred: wherein Q is one or more of a divalent group such as S02-, -O-, -RaRbC-, -NH-, CO-, -CONH-, -OCONH-, and the like, Ra and Rb can each be independently one or more of hydrogen, phenyl, alkyl of 1 to about 4 carbon atoms, alkenyl of 2 to about 4 carbon atoms, fluoride, cycloalkyl of 3 to about 8 carbon atoms and the like, x can be 0 or 1, and it can be 0 or 1 and it is 1 when x is 1, and z can be 0 or a positive integer, typically not greater than about 5.

Another preferred class of hardeners are aliphatic amines such as alkylene amines. Illustrative of suitable alkylene amines are the following: monoethanolamine, ethylenediamine, N- (2-aminoethyl) ethanolamine, diethylenetriamine, piperazine, N- (2-aminoethyl) piperazine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, diaminoethylpiperazine, piperazinoethylethylenediamine, 4-aminoethyltriethylenetetramine, tetraethylenepentamine, aminoethylpiperazinoethylethylenediamine, piperazinoethyldiethylenetriamine, and the like. Another class of hardeners, which may also be used as extenders of the epoxy resin, are poly (oxyalkylene) polyamines of higher molecular weight such as those of the following formulas: CH, CH, H-CHCH ^ OCHjCH ^ NH. where v is 2-40 where a + c is approximately 2 and b is 8-45 where x, y and z are in the range of 2-40 CH, CH > CH, H ^ CHCH OCHjCHLNHÍO CH-CH NR. where m + d is approximately 82-86 Preferred hardeners are diamines of the formula: The hardener may be a monoamine such as aniline, para-aminophenol and alkylated versions thereof. Other desirable hardeners are the reaction products of dialkylamines, such as dimethylamine, diethylamine, methyletylamine, di-n-propylamine, and the like, with a variety of mono and diisocyanates to form mono and diureas. Any of the polyisocyanates listed below can also be reacted for use as a hardener. The specific illustration of useful hardeners are those encompassed by the following formulas and descriptions: where Ry is a monovalent group; Rx is alkyl, halo, alkoxy and the like; Rz is methylene, isopropylidene, ethylidene or a covalent bond and s is 0-4. The preferred urea hardeners are those which are the reaction products of dimethylamine with mixtures of 80% 2,4-tolylene diisocyanate and 20% 2,6-tolylene diisocyanate, polymeric diisocyanate, p-chlorophenylisocyanate, isocyanate or phenyl isocyanate. , 4-dichlorophenyl. Accelerators can also be used and include imidazoles and substituted ureas. Examples include 2-ethyl-4-methylimidazole and p-chlorophenyl-1,1-dimethylurea. The amount of the hardener employed is usually stoichiometric on the basis of an amine group by a peroxy group on the resin. If the epoxide is a triepoxide and the hardener is a diamine, then the molar ratio of the hardener to epoxide could typically be about 2.5 / 3 or 0.83. A typical formation could have a weight ratio of epoxy resin to hardener from about 3/2 to about 4/1. Where any of the hardeners serve primarily as extenders of the epoxy resin, then the amount of hardener in the typical case will be less than that generally employed to harden the epoxide. Mixtures of the above hardeners and other hardeners are within the contemplation of this invention. Other Useful Resins As indicated above, other reactive resin systems are also suitable which include the various thermosettings or thermosetting resins including bismaleimide (BMI), phenolic resins, polyester resins (especially unsaturated polyester resins, typically used in the production of SMC), PMR-15 polyimide, esters of bis-aryl cyanate and resins terminated in acetylene. A resin particularly suitable for this application is the vinyl ester resin. This kind of resin is based on the reaction of unsaturated carboxylic acids and epoxy resins or epoxy compounds. The remaining illustrative for the formation of vinyl esters are the following: Unsaturated Acids: Epoxy Resins: Typical of the vinyl esters are as follows: In the above formulas, w is a positive value of from about 1 to about 20, preferably from about 2 to about 10. Vinyl ester resins, alone or in combination may be used. monoethylenically unsaturated monomers, such as styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, ethylstyrene, O-vinylxylene, O-chlorostyrene, O-bromostyrene, vinylbenzylchloride, p-tert-butylstyrene, methyl methacrylate, methyl acrylate, propyl acrylate, butyl acrylate, butyl methacrylate, propyl methacrylate, butyl methacrylate, lauryl acrylate, 2-ethylhexyl acrylate, ethyl methacrylate and the like. dimethylglycol dimethacrylate, 1,4-divinylbenzene and the like. In the foregoing, n is 0 or 1. A number of vinyl ester resins require the use of solvents such as methyl ethyl ketone, acetone, toluene and the like. The vinyl esters can be cured by any free radical mechanism, such as by photoinitiation and / or by the use of peroxy compounds. A photoinitiator can be included in the formulation, as an optional ingredient. Curing initiated by light of the parent only or in combination with other polymerizable materials indicates the photosensitization of the light sensitive compounds by ultraviolet light or visible light, which in turn, initiates the polymerization of the resin materials. The photoinitiator may comprise a combination of a photosensitive ketone and a tertiary amine. Photosensib J ketones are typical include benzophenone, acetophenone, thioxanten-9-one, 9-fluorenone, anthrachone, 4 '-methoxyacetophenone, diethoxyacetophenone, biacetyl, 2,3-pentadione, benzyl, 4,4' -methoxybenzyl, 4, 4 ' -oxidibenzyl and 2, 3-bornadone (di canfroquinone). Typical tertiary amines include ethyl-4-d? Meth? Aminobenzoate, et? L-2-d? Meth? Aminobenzoate, 4,4'-bis- (dimethylamino) benzophenone, N-methyldiethanolamine, and dimethylammobenzaldehyde. Any known photosensitization system that can work effectively when exposed to light can substitute for the compounds or combinations named above. The amount of the photoinitiator may be sufficient to initiate the polymerization in a selected ream and complete it completely within about half a minute when the ream composition is exposed to a visible light output of at least 5,000 candela. In addition, any known free radical scavenger (antioxidant) such as butylated hydroxytoluene, can be used to deoxidize small amounts of free radicals generated, during long-term storage. The curing of vinyl ester is effected primarily by a thermal initiator, which is a thermal curing agent, typical known in the art. Illustrative of these, are benzoyl peroxide, dicumyl peroxide, ethylmethyl ketone peroxide, tertiary butyl peroxide, tertiary butyl hydroperoxide, tertiary butyl perbenzoate, Luperox 118 (sold by Wallace and Tiernan, Lucidol Division, 1740 Military Road, Buffalo, NY 14240), cumene hydroperoxide, or other suitable peroxides may initiate the polymerization of the ethylenically polymerizable unsaturated components of the primary coating. For example, benzoyl peroxide can be used together with 2-hydroxy et? L-p-tolu? Dma. It is common to combine metal salts such as naphthenates, for example, cobalt naphthenate and the like, with tertiary amines, such as dimethylanil, with the peroxidic catalyst. The amount of the catalyst is typically that amount which facilitates cure within at least ten hours at a temperature greater than 25 ° C. Generally, the catalyst system will be less than about 10 percent by weight of the beef formulation. As a rule, the catalyst system will be in the range of from about 0.1 to about 8 percent by weight of the resin formulation. Thickening As indicated above, the thickening of the resin in the formation of the film involves the combination in the resin formulation of i) one or more electronic grade fillers: ii) a thermoplastic resin that is soluble or partially soluble in the thermosetting resin; iii) an elastomer-type polymer that provides discrete elastomer phases (second phases) in the thermosetting resin matrix; iv) a thixotropic; and v) a mixture of two or more of i), ii), iii) and iv). Illustrative of the suitable electronic fillers are aluminum oxide, including alumina trihydrate, coated aluminum nitrate, silicon carbide, diamond, thermosetting resin reinforced with ground-cured fiber, as well as a variety of thermoplastic and thermoplastic fibers. The thermoplastic polymer used to form these fibers can be made of condensation type polymers, such as nylon-6,6; nylon-6; nylon-4,6- polyethylene terephthalate polyester; polyaramide Klevlar ™; polycarbonate (i.e., poly (2,2-bis (1,4-oxyphenyl) propane carbonate)); polyarylates (i.e., poly (2,2-bis (1-4-oxyphenyl) propane terephthalate); polyimides; polyetherimides, such as Ultem ™ 2; polysulfones (see U.S. Patent Nos. 4,175,175 and 4,108,837, such as UdelMR and RadelMR A-4003, the polyethersulfones (see U.S. Patents Nos. 4,008,203, 4,175,175 and 4,108,837), such as Victrez ™ 4, polyarylsulfones, polyarylamidoimides, such as Torion® 5, and acrylic and modacrylic fibers, and the like The thermoplastic polymer used to provide the thermoplastic polymer can also be made by condensation polymers used to form the film, such as nylon-6, 6, nylon-6, nylon-4,6-polyethylene terephthalate polyester, polyaramide Klevlar ™. polycarbonate (i.e., poly (2,2-bis (1,4-oxyphenyl) propane carbonate); polyarylates (ie, poly (2,2-bis (1-4-oxyphenyl) propane) terephthalate; polyimides; polyetherimides, such as UltemMR 2; polysulf Ones (see U.S. Patent Nos. 4,175,175 and 4,108,837, such as UdelMR and RadelMR A-4003; the polyethersulfones (see U.S. Patent Nos. 4,008,203, 4,175,175 and 4,108,837), such as Victrez ™ 4; polyarylsulphones; polyarylamideimides, such as Torion ™ 5; and similar.

A particularly preferred class of thermoplastic polymer to provide stiffness and as a flow control aid for thermosetting resin formulations are polyurethanes of the formula: wherein a and b are each 1, 2 or 3, n is at least 1, X is a divalent organic radical containing at least two carbon atoms where the N is attached to different carbon atoms of X, R is a polyester aliphatic or polyalkylene oxide, wherein the aliphatic polyester is a polyester of an alkylene diol and an aliphatic carboxylic acid, or a polycaprolactone polyol, and. the alkylene group of the polyalkylene oxide contains on average more than three carbon atoms and not more than five carbon atoms, and available from General Electric Company, Plastics Business Group, Pittsfield, MA. 3Fitted by Amoco Performance Products Inc. "Available from ICI Advanced Materials, Wilmington, DE 19897 5D? Spomble from Amoco Chemical Company, Chicago, 111.

Ro is an organic aromatic group that contains a group in which OH and N linked to the Ro group are directly attached to the different aromatic carbon atoms.

The synergistic combinations of the polymer of the formula (I) and other hardening polymers are useful for improving the hardening properties of the thermosetting resin formulations for making printed circuit board compounds. This invention includes using in the thin film thermosetting resin formulation, a linear, partially miscible or miscible polyurethane polymer containing phenolic hydroxyl functionality for reaction with a thermosetting resin comprising a linear polyurethane of recurring units containing linear or linear ester. ethers portions, or a combination of ester or ether portions, which are interlinked through the urethane and uride groups linked to the terminal groups containing phenolic hydroxyl. These linear polyurethane hardening polymers can contain urethane bound to phenolic hydroxyl-containing end groups of the formula: wherein a and b are each 1, 2 or 3, n is at least 1, X is a divalent organic radical containing at least two carbon atoms where the N is attached to different carbon atoms of X, R is a polyester aliphatic or polyalkylene oxide, where. the aliphatic polyester is a polyester of an alkylene diol and an aliphatic carboxylic acid, or a polycaprolactone polyol, and. the alkylene group of the polyalkylene oxide contains on average more than three carbon atoms and not more than five carbon atoms, and Ro is an organic aromatic group containing a group in which the OH and N linked to the group Ro are directly attached to the different carbon atoms and the OH is directly attached to an aromatic carbon atom. An improved version of the polymer of the formula (I) is the polymer of the formula (II). wherein x and y are 0 or 1, R 'is hydrogen or alkyl of 1 to 3 carbon atoms, and R1, R2, R3 and R4 are hydrogen, nitro, halogen, or alkyl of 1 to about 4 carbon atoms. In a preferred embodiment of formula (I), the carbons to which the OH and N are attached are separated from each other by at least one aromatic carbon atom. A more desirable embodiment is a hardener polymer of the formula: In this embodiment, ROI is a divalent organic group and c is 0 or 1. In a preferred embodiment of the invention, with respect to the polymer of formula (II), x and y are 1, R1, R2, R3 and R4 are hydrogen, a and b are 1 and n has a value such that the weight average molecular weight of the polymer is from about 20,000 to about 120,000. By incorporating this preferred embodiment in formula (III), ROI is methylene or c is 0. In a preferred additional embodiment it is a polymer having the formula: wherein n has a value such that the weight average molecular weight of the polymer is from about 30,000 to about 110,000 and r is a polyalkylene oxide in which the alkylene groups thereof have an average value of about 3.5 to about 4.5 carbon atoms. A polyurethane polymer has the formula: [V] wherein n has a value such that the weight average molecular weight of the polymer is about 35,000, at about 100,000 and f has a value of at least 1, preferably from 1 to about 70, more preferably about 4 to about 55, and more preferably from about 6 to about 42. The terminal hydroxyl groups may be in the ortho, meta or para positions, preferably in the para position. A preferred polyurethane is one having a molecular weight of from about 20,000 to about 120,000, preferably from about 30,000 to about 110,000, and more preferably from about 35,000 to about 100,000, formed by the reaction of a diol of oligoxide. 1,4-butylene having a molecular weight of about 650 to about 5,000 with a stoichiometric excess of methylene diphenyldiisocyanate capped by reaction with, or, p-aminophenol. The polyurethane polymer suitable for use in the thermosetting resin film formulation can have a modification such as those made by the following reactions: These polyurethane polymers are especially crowned linear polyurethanes, formed by the reaction of a diisocyanate of the formula 0 = C = NXN = C = 0 with an alkylene diol of the formula HO-R-OH in the molar ratio (0 = C = NXN = C = 0 / H0-R-0H) of > 1, in such a way that the resulting polymer equals the value of n, as defined above, followed by the reaction with aminophenolic compounds. Suitable diisocyanates for use in the formation of suitable polyurethanes include the following: bis TABLES and their mixtures. The preferred polyisocyanates are TDI, ie the mixture of 80% of 2,4-tolinediisocyanate and 20% of 2,6-tolylene diisocyanate, or the individual monomer 2,4-tolinediisocyanate (2,4-TDI) and 2, 6 -tolylene diisocyanate (2,6-TDI) and MDI, that is, 4, 4 '-diphenylmethylene diisocyanate and 3, 3'-diphenylmethylene diisocyanate, or the individual monomer 4, 4'-diphenylmethylene diisocyanate (4,4'-MDI) or 3, 3'-diphenylmethylene diisocyanate (3,3'-MDI). The ether or polyalkylene oxide diol comprises a divalent alkylene oxide moiety, wherein the alkylene groups contain on average more than three carbon atoms and no more than five carbon atoms. Typically, they are based on ethylene oxide, 1,2-propylene oxide, 1,3-propylene oxide, 1,2-butylene oxide, 1,3-butylene oxide, 1,4-butylene oxide. , 1,2-pentylene oxide, 1,3-pentylene oxide, 1,4-pentylene oxide, 1,5-pentylene oxide, 1,2-hexylene oxide, only generally polymerized when the alkylene group contains more of 3 carbon atoms, or as mixtures, such as to form a carbon content of the average alkylene in number greater than about 3 and as high as about 5, preferably greater than 3.5 and as high as about 4.5. Many types of alkylene oxide diols are available for the production of urethanes, but all those having an alkylene average below about 3.5 have higher water absorption properties for use in high performance adhesive applications. Such examples include the homooligomers of propylene oxide diols from the consideration of the urethane hardeners, all the polyalkylene oxide diols used to form the thickeners / auxiliaries of flow control. Polyurethane prepolymers are alkylene oxide prepolymers created by the polymerization of monomeric aiquiietioxide.This formation of prepolymer as well as taibiér their reactions to form polyurethanes is well known.Prepolymers, one preferred is based on polymerization of full 1,4-buf oxide (ie, tetrahydrofuran.) for a molecular weight of about 650 to about 5.00 C. Such prepolymers are commercially available from DuPont under the name Terathane.RTM .. The molecular weight range of Teratha " iesR is as low as approximately 650 to as high as approximately 2900, as well as molecular weight versions of approximately 1000 and 2000. Versions of lower and higher molecular weights are also available. Such prepolymers provide low water absorption, flexible molecular structure, hydrolytic stability and commercial availability at a moderate cost. The TerathanesR have the formula H0 (CH2CH2CH2CH20) tH wherein t has a value of about 8-9, at about 40, the upper and lower values are available, and such oligomers can be used to make the polyurethanes. The Terathanes® have been widely recommended for use in the manufacture of polyurethanes by DuPont. For example, they have been recommended by DuPont for use in the formation of soft segments in polyurethanes. When TDI is used, DuPont advises that amines such as 4,4'-methylenebis (2-chloroaniline) are favored as chain extenders or curatives. If 4.41-MDI is the extensive chain, DuPont advises that 1,4-butanediol is favored as the extensive chain. However, this invention does not depend on other chain extenders or curatives although chain extenders may be employed to raise the molecular weight of lower polyurethane prepolymers, prior to the crowning step to form the polyurethanes. Polyester diols useful in making the polyurethanes are based on the reaction products of an aliphatic dicarboxylic acid derivative (such as acid halide or ester) and an aliphatic diol derived from a polyalkylene oxide diol, such as an alkylene glycol to about 5 carbon atoms, or based on the reaction of + ***** + sign + ** caprolactone with an initiating organic diol. These polyester diols are commercially available materials. These are typically less hydrolytically stable than the polyalkylene oxide diols defined above. Those which are desirable in the practice of the invention, are those which possess low water absorption, flexible molecular structure, hydrolytic stability, and commercial availability at a moderate cost. The linear polyester resins can be reaction products of saturated and unsaturated aliphatic dicarboxylic acids, such as malonic acid, succinic acid, adipic acid, maleic acid, fumaric acid, hexhydro or tetrahydrophthalic acid, "dimer" acid (dimerized fatty acids), and their respective anhydrides (where possible chemically), acid halides and esters with organic diols. The polyester may include in the reaction a minor amount, typically not more than 20% per mole, preferably not more than 10% mole, of the acidic component of the polyester, of an aromatic dicarboxylic acid, such as anhydrous acid or anhydride. phthalic acid, isophthalic acid, terephthalic acid, their respective anhydrides (where possible chemically), acid halides and esters, in addition to the above polyesters can also be used modified unsaturated cyclopentadiene polyesters such as those described in U.S. Patent Nos. 3,986,922 and 3,883,612, while the polyester is linear. The organic diol used to produce the polyester can include the alkylene glycols, such as ethylene glycol, propylene glycol, butylene glycol, dipropylene glycol, diethylene glycol, neopentyl glycol, and the like, and the polyalkylene oxide glycols such as triglyme (boiling point 216 ° C), tetraglime (bp 276 ° C), tripropylene glycol, tetrapropylene glycol, and the like. The chain termination of the linear polyalkylene oxide or polyester polyurethanes is carried out by reacting more than one mole of the diisocyanate for each mole of the polyalkylene oxide and / or polyester diol. The amount of the stoichiometric excess of the diisocyanate will determine the degree of polymerization (n) of the polyurethane. A stoichiometric amount of the diisocyanate for the diol is one mole of each. If the reaction is carried out under anhydrous conditions, using an excess of the diisocyanate over the stoichiometric amount results in a polymer that is a chain terminated with isocyanate groups at each end. If any water is present in the polyurethane formation stage, then stoichiometrically must be taken into account since the water will generate more urea than is found in the nearby terminals, as well as termination isocyanate groups attached thereto. The level of excess diisocyanate will determine the degree of polymerization and thus determine the value n in the above formulas. Such an isocyanate-terminated polymer is not a thermally or chemically stable polymer. The hydroxy aromatic amino compound for terminating the polyurethane containing the isocyanate is preferably a structure of the formula: wherein the combination of ROO and R02 is equivalent to Ro and ROI defined above, and in particular, ROO can be a covalent bond or a non-aromatic divalent group such as alkylene, alkylidene, oxygen, carbonyl, sulfone, and the like, d is 0 or 1, and when it is 1, the dotted line that designates a bond of the fused ring does not exist, and when d is 0, the dotted line may exist as a bond of the ring fused to R02. R02 is aryl, polyaryl, fused ring aryl, cycloalkyl and the like, and c is 0 or 1. When d is 1, c is 1, and when d is 0, c may be 0 or 1. R03 is hydrogen or alkyl of 1. to about 14 carbon atoms. Illustrative examples of suitable amines are the following: "O, xr -xx ----, joro.

The aminophenols, p, m or o-aminophenol, prove to be effective termination molecules for polyurethanes capped with isocyanate. The solubility or low melting point gives the target product some advantage but p-aminophenol easily dissolves in the hardener polymer - epoxide reaction system at generally used temperatures (80-120 ° C). The low molecular weight of these aminophenols (109.1) means that relatively small amounts can be used for termination, the solubility is high, the termination reaction is rapid, mostly governed by the time required to obtain a good dispersion in a solvent system. high viscosity The aminophenol powder can be directly added to the reaction mixture or more desirably can be sprinkled, mixed with a small portion of the lower oligomeric epoxide resin diluent, discussed below, and then added. The measurement of the IR absorption ratio of the isocyanate group from peak 2240 cm-1 to 2840 cm-1 peak CH can be used to ensure that the termination is complete. During the polymerization of diisocyanates with hydroxy-terminated polyester or alkylene oxide-based materials, high molecular weights (approximately 20K-120K, more typically in the range of about 30K to about 100K) are obtained. As a result, the viscosities become very high and at rational reaction temperatures (about 50-170 ° C, preferably about 80 ° C-120 ° C), stirring in a laboratory or production equipment may become difficult. The use of a solvent as a diluent (for example, methyl ethyl ketone (MEK), tetrahydrofuran (THF), and the like) of the reactants and the reaction products, although usable to form the polymers of the invention, adds the problem of their elimination Subsequent with a concomitant increase in the cost of production. It takes advantage of the very low reactivity of hydroxyl groups with epoxide groups (unless they are catalyzed) and also the low reactivity of isocyanate groups with epoxide groups (unless the formation of the oxazolidone complex was deliberately forced). Therefore, oligomer-free epoxide resins and thus secondary hydroxyl-free, can be used as non-reactive diluents during polymer formation. Such epoxy resins are subsequently compatible with the necessary formulation in future adhesive systems. For this dilution during the reaction, epoxides as free as possible of oligomers can be used. Shell EponR 825 (diglycidyl ether of bisphenol A) has been used successfully as a diluent even though the small amount of oligomer present (5%) does not show any reaction. In a 1/1 ratio for a total derivative polymer, EponR 825 gives easily stirred polymer products at necessary production temperatures and at that level it must meet most of the subsequent formulation needs. D.E.N.R 332 of Dow Chemical should also be suitable. Bis F resins, such as Epiclon® 830S, if distilled to remove oligomers, can also be used. Illustrative of suitable diluents are epoxy monomers and epoxy dimers of the following formula: wherein Ra and Rb are each hydrogen, alkyl of 1-3 carbon atoms or phenyl, preferably alkyl such as methyl, and p has a value of 0 to < 1, preferably less than about 0.2. More preferably, p is equal to 0. The reaction conditions for forming the polyurethane from the diisocyanate and the diol is a temperature from about 50 ° C to about 200 ° C with mixing in the presence of a diluent, such as a solvent conventional, as indicated above, or the reactive diluent comprises the epoxy monomer resin indicated above. The reaction can be carried out in the absence of added water, and anhydrous conditions are preferred. Conditions that remove water from the reagents before the reaction and during the reaction are desirable. No special catalysts are necessary to effect the reaction, but a catalyst that does not adversely affect the reactions can be employed. Catalysts are necessary in polymerization reactions using aliphatic isocyanates. The polyurethanes mentioned above and their manufacture are described in copending US Application S.N. 08 / 349,876, filed December 6, 1994. Another class of thixotropic elastomer-type agents and / or polymers auxiliary to flow control that provide discrete phases of elastomer (second phases) in the thermosetting resin matrix. Certain of these materials can reduce, to some finite degree, the crosslink density of the thermoset resin (graded C). Most of these materials introduce very favorable properties for resulting thermosetting resin. For example, a particularly desirable material for this purpose is an elastomeric polymer containing soft or hard segments, the hard segments act or form upon processing, crosslinking of the elastomeric type. Some of these elastomeric types contain functional end groups which allow them to be coupled with complementary functional monomers or polymers to form the desired in situ elastomer of the thermosetting resin and to carry the latter non-drainable and sticky while hardening the cured resin. As a class, these elastomeric polymers act or are crosslinked yet are thermoprocessible, which when discreetly provided in the matrix resin reach the resin to be neither drapable nor sticky and also harden it. Another class of ABS (acrylonitrile-1, 4-butadiene-styrene) thermoplastic polymers of suitable elastomer type which are typically used as modifiers of other resin systems. They are characterized as having a wide range of properties, although the preferred systems of the invention use copolymers that are of the higher rubber type which, when compared to other copolymers of this type have a relatively low tensile strength, tensile modulus. low, higher impact resistance, lower hardness and heat deflection temperature. Another elastomer that has been found desirable are liquid butadiene acrylonitrile copolymers terminated in carboxyl and amine. Such copolymers can contain pendant carboxyl groups in the interior of the polymer structure through the inclusion of methacrylic or acrylic acid in the polymerization or through the hydrolysis of some of the pendant nitrile units. Such polymers react with the epoxy resin and as a result, the epoxy forms the hard segment that generates the properties of the elastomer. Another class of thermoplastic elastomer is KratonR, available from Shell Chemical Company. These thermoplastic rubber polymers possess usable thermoplastic properties. These can be softened and flow under heat and pressure. They then recover their cooling structures. The chemical construction is of three discrete blocks of type A-B-A linear. Styrene-butadiene-styrene (S-B-S) block copolymers of styrene-isoprene-styrene block (S-B-S) and styrene-ethylene / butylene-styrene block copolymers (S-EB-S) are available as block copolymers. They are characterized by the styrene polymer termination blocks and an elastomeric intermediate block. After processing, the polystyrene termination blocks are physically crosslinked, they enclose the rubber net in place. This physical crosslinking is reversible under heating. Another series of KratonR thermoplastic rubbers are diblock polymers in which one block is hard thermoplastic and the other is soft saturated elastomer. Illustrative of these series is Kraton® G 1701, a diblock polymer of a hard polystyrene block and a saturated, soft block of poly (ethylene-propylene). Other rubbers or elastomers include: (a) homopolymers or copolymers of conjugated dienes having a weight average molecular weight of 30,000 to 400,000 or more as described in U.S. Patent No. 4,020,036, in which the conjugated dienes contain of 4-11 carbon atoms per molecule, such as 1,3-butadiene, isoprene, and the like; (b) epihalohydrin homopolymers, a copolymer of two or more epihalohydrin monomers, or a copolymer of an epihalohydrin monomer with an oxide monomer having a number average molecular weight (Mn) which ranges from about 800 to about 50,000 as is described in U.S. Patent No. 4,101,604; (c) chloroprene polymers including chloroprene homopolymers and copolymers of chloroprene with sulfur and / or with at least one copolymerizable organic monomer in which the chloroprene constitutes at least 50 weight percent of the organic monomer constructed from the copolymer as described in U.S. Patent No. 4,161,471; (d) hydrocarbon polymers including ethylene / propylene dipolymers and ethylene / propylene copolymers and at least one non-conjugated diene such as ethylene / propylene / hexadiene / norbornadiene, as described in U.S. Patent No. 4,161,471; (e) conjugated butyl diene elastomers, such as copolymers consisting of 85 to 99.5% by weight of C4-C5 isolefin combined with 15 to 0.5% by weight of a conjugated multiolefin having 4 to 14 carbon atoms, isobutylene copolymers and isoprene wherein a major portion of the combined isoprene units therein has conjugated diene unsaturation, as described in U.S. Patent No. 4,160,759. Specific illustrations of suitable elastomeric polymers are the following: 1. Hycar ™ CTBN liquid reactive rubbers, carboxyl-terminated butadiene-acrylonitrile copolymers, sold by B. F. Goodrich. 2. Hycar ™ CTBNX, similar to CTBN except containing internal pendant carboxyl groups, also supplied by B. F. Goodrich, 3. HycarRM ATBN, amine-terminated butadiene-acrylonitrile copolymers sold by B. F. Goodrich. 4. K 1102-28: 72 linear styrene-butadiene SBS polymer, available from Shell Chemical Company as Kraton® 1102. 5. KDX 1118 30:70 styrene-butadiene copolymer containing 20% triblock SBS and 80% diblock SB , available from Shell Company Chemical Company as Kraton® DX 1118. 6. KG 1657-14: 86 styrene: ethylene-butylene: styrene copolymer available from Shell Chemical Company as KratonR G1657. 7. S 840 A-Stereospecific rubber 43:57 of styrene-butadiene, available from Firestone Synthetic Rubber & Latex Company as StereonR 840A. 8. SBR 1006-random 23.5: 76.5 copolymer rubber from block SB styrene: butadiene available from Goodrich Chemical Company as Ameripol® 1006. 9. SBR 1502-Random 23.5: 77.5 Styrene rubber: butadiene available from Hules Mexicanos, from Goodrich Rubber Company as AmeripolMR 1502. 10. Blande? MR modifying resins (for example, 305, 310, 311, 336, 338 and 405) - ABS polymers sold by General Electric. Different varieties are available and the ones that are appropriate depend on the properties sought.

Additional flow reductions are provided by thixotropic agents, such as fumed silica. Illustrative thixotropic agents are fumed silicas of large surface area and fumed silicas of organosilyl block and the like. The thin film can be characterized as non-emptied. Optionally, the film can also be sticky. This condition can be achieved in a variety of ways. Many thermosetting resins are solid at about 23 ° C and many of them are liquid at these temperatures. Both types of resins can be made as non-drainable and sticky fluids. For example, a resin that is solid and a resin that is liquid can be combined to form a mixed resin system that is non-drainable and sticky. In addition a solid or liquid thermosetting resin may be incorporated in a variety of diverse materials that will carry the resin to the non-drainable fluid under conventional handling temperature conditions and a non-drainable, sticky fluid at room temperature (approximately 15-37 ° C). C). Conventional handling temperatures are defined as a temperature between about -20 ° C to about 43 ° C6. Although the thermoplastic particles expandable in situ or the solid chemical blowing agent will lead to a liquid thermosetting resin to be more viscous, they are not alone effective to form the film that can not be emptied. If the thermosetting resin is solid, it can be laminated into a film by melting the resin with heat under conditions that prevent condensation or addition of the resin to a thermofixed condition (engrave C). If the resin is u liquid, it can be mixed coa This range reflects the fact that the handling of the material may require a low temperature of hot water to prevent the reaction of the thermoset resin system and relatively high temperatures since the film can be used on a hot factor bath. . thixotropic agents, other solid and / or liquid resins or thermoplastic elastomeric modifiers for converting the resin of a liquid to an aoctable and sticky material. The thermoplastic polymer used to form the exible thermoplastic particles in situ is easily prepared from a wide variety of materials. A variety of patents refers to their manufacture. For example, U.S. Patent No. 3,615,972 describes its preparation by polymerizing the monomer from an aqueous dispersion of (1) organic monomeric materials suitable for polymerizing to a thermoplastic resinous material having the desired physical properties, (2) an agent of elevation or liquid blowing to which exerts a low action of solvent on the resulting polymer, and in an excess amount thereof which is soluble in the polymer and (3) a dispersion stabilizing material that is used to maintain the dispersion . The resulting solid spherical particles have a quantity of the liquid blowing agent encapsulated therein, as a separate and distinct phase. Thermoplastic polymers are formed by the polymerization of one or more of different types of alkenyl monomers such as those of the formula: Rox I CH ^ C-X, to form homopolymers or copolymers, such as random or ordered copolymers, (including blocks). In the above formula, Rox can be hydrogen, alkyl, such as methyl, ethyl and the like, or halogen, such as chlorine, fluorine, bromine or iodine, and XI can be an aromatic containing a bound portion via an aromatic carbon atom , an ester portion of carbonyloxy, halogen, cyano, oxycarbonyl ester, carboxyl and the like. Illustrative of these monomers are those in which XI is aromatic containing such as styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, ethylstyrene, O-vinylxylene, O-chlorostyrene, O-broastyrene, vinylbenzene chloride, p- ter-butyl styrene and the like. Also illustrative of these monomers are those in which XI is a carbonyloxy ester portion to form acrylates alone or in combination with the alkylene aromatic monomers, can also be used. Such monomers of the acrylate type include methyl methacrylate, ethyl acrylate, propyl acrylate, butyl acrylate, butyl methacrylate, propyl methacrylate, butyl methacrylate, lauryl acrylate, ethylhexyl 2-acrylate, ethyl methacrylate, and the like . XI and Rox can be a halogen, such as chlorine, fluorine, bromine and iodine, thus covering the formation of copolymers of vinyl chloride and vinylidene chloride, acrylonitrile with vinyl chloride, vinyl bromide and halogenated vinyl compounds Similar. XI can be a cyano group and this includes polymers of acrylonitrile and methacrylonitrile, XI can be an oxycarbonyl ester, such as vinyl ester, for example, vinyl acetate, vinyl butyrate, vinyl stearate, vinyl laurate, vinyl myristate. , vinyl propionate and the like. Ethylenically unsaturated copolymerizable acids such as acrylic acid, methacrylic acid, itaconic acid, citraconic acid, maleic acid, fumaric acid, vinylbenzoic acid and the like can also be employed for specific purposes. The thermoplastic polymers may also include copolymers (of random or ordered varieties, especially block copolymers) -of the monomers described above, with a variety of hydrocarbon monomers, such as propylene, butene and one or more dienes, such as:. straight chain acyclic dienes such as: 1,4-hexadiene, 1,6-octadiene, and the like; . straight chain acyclic dienes such as: 5-methyl-1,4-hexadiene, 3,7-dimethy1-1,6-octadiene, 3,7-dimethyl-1,7-octadiene and mixed isomers of dihydromyrzene, dihydroocycene, and Similar. . single ring alicyclic dienes such as: 1,4-cyclohexadiene, 1,5-cyclooctadiene, 1,5-cyclododecadiene, and the like; . fused and dotted multi-ring alicyclic dienes such as: tetrahydroindene, methyltetrahydroindene, dicyclopentadiene, bicyclo- (2, 2, 1) -hepta-2, 5-diene, alkenyl, alkylidene, cycloalkenyl and cycloalkylidene norbornenes such as 5-methylene-2 -norbornene (MNB), 5-ethylidene-2-norbornene (ENB), 5-propyl-2-norbornene, 5-isopropylidene-2-norbornene, 5- (4-cyclopentenyl) -2-norbornene, 5-cyclohexylidene-2 -norborneno, and the like. The thermoplastic polymer used in the formation of expandable thermoplastic particles in situ can also be made from the condensation type polymer such as nylon-6,6; nylon-6; nylon-4,6-polyester polyethylene terephthalate; polyaramide Klevlar ™; polycarbonate (i.e., poly (2,2-bis (1,4-oxyphenyl) propane carbonate carbonate)); polyarylates (i.e., poly (2,2-bis (1-4-oxyphenyl) propane terephthalate); polyimides; polyetherimides, such as Ultem ™ 2; polysulfones (see U.S. Patent Nos. 4,175,175 and 4,108,837, such as UdelMR and RadelMR A-400, polyethersulfonates (see U.S. Patent Nos. 4,008,203, 4,175,175 and 4,108,837), such as Victrez®, polyarylsulfones, polyarylamideimides, such as Torlon®, and the like. of blowing or lifting agents within the polymerization system, which may be agents that form volatile fluids, such as aliphatic hydrocarbons, including ethane, ethylene, propane, propylene, butene, isobutylene, neopentane, acetylene, hexane, heptane or mixtures of one or more such aliphatic hydrocarbons having a molecular weight of at least 26 and a boiling point below the range of the softness point of the resinous material when saturated with the Blown particular used. Other suitable fluid forming agents are chlorofluorocarbons such as those described in U.S. Patent 3,615,972 (column, lines 21-30) and tetraalkylsilanes such as tetramethylsilane, trimethylethylsilane, trimethylisopropylsilane and trimethyl-n-propylsilane. As indicated in this patent, the boiling point of such foaming agents at atmospheric pressure should be approximately in the same temperature range or lower at the softening point of the resinous material used. Blowing agents such as Freons®, such as trichlorofluoromethane, hydrocarbons such as n-pentane, i-pentane, neo-pentane, butane, i-butane, azodicarbonamide are commonly suggested blowing agents found in this type of expandable particles in situ. Typically, the non-expandable particles contain from about 3 to about 40% by weight of the blowing agent. As indicated in U.S. Patent No. 4,397,799 patented on August 9, 1983, the particle size may vary from the expanded particles, as well as the expanded microspheres. The particle sizes for the unexpanded particles may be in the range, for example, from about 1 μm to about 1 mm, preferably from about 2 μm to about 0.5 mm. A version of expandable particles in situ is sold under the name Expancel®, by Nobel Industries Sweden, Sundsvall, Sweden (U.S. adress: Marrietta, GA 30062). They are in the range of non-expandable particle size from about 5 μm to about 50 μm. The particle diameters expand 2 to 5 times. Preferably, the in-place expandable particles used have a mixed dispersed particle size to achieve the best packing, an expansion in the syntactic molding foam. A particularly preferred in situ expandable particle is Expancel® 091 DU, which is believed to be a terpolymer of vinylidene chloride, acrylonitrile and methacrylonitrile containing 10-18% by weight of isopentane and possesses the following properties: average unexpanded particle size of approximately 12 μm with a dispersion of approximately 5-50 μm; true density (expanded in water at 100 ° C, kg / m3), < twenty; TMA - T (start) ° C, 125-130; T (max.) ° C; about 183; TMA density, kg / m3 < 17. The particles of the chemical blowing agent (with a particle size in the range of about 1 μm to about 1 mm, preferably from about 2 μm to about 0.5 mm) which can be incorporated are solid inorganic and organic compositions which they typically decompose at a particular temperature to generate a volatile component (gas) that causes microcell formation in the thermoformed matrix. Typical inorganic blowing agents include ammonium carbonates and bicarbonates, metal alkyl carbonates, and bicarbonates such as lithium carbonate, sodium carbonate, potassium carbonate, rubidium carbonate, cesium carbonate, carbonate and bicarbonate mixture also as mixtures of metal alkyl from the carbonates and bicarbonates. These carbonates and bicarbonates can do to decompose at low temperatures by incorporating organic carboxylic acids and accelerators of acid anhydride blowing agents into the formulation. Suitable carboxylic acids and anhydrides are citric acid, acetic acid and anhydride, maleic anhydride. These are a variety of chemical blowing agents sold under the name of Celogen ™ (Naugatuck Chemical Division of the US Rubber Company (Uniroyal)) which includes toluenesulfonyl hydrazide, toluenesulfonyl semicarbazide, 5-phenyltetraazole, azodicarbonamide, and the like, which are excellent agents of blowing chemicals suitable for the purposes of the invention. Chemical blowing agents can be used in the formulations of the invention in amounts ranging from about 0.1 to about 3 parts by weight, preferably from about 0.5 to 2.0 parts by weight, of the thermosetting resin formulation.

Low Profile Additives Certain thermoplastic materials known in the field as low profile additives can be incorporated into the thermosetting resin formulation. These may be vinyl acetate polymers, acrylics, saturated polyesters, polyurethanes, styrene-butadiene and similarly used materials. The low profile additives of vinyl acetate polymers, suitable thermoplastics are thermoplastic poly (vinyl acetate) homopolymers and copolymers containing at least 5 percent by weight of vinyl acetate. Such polymers include, for example, vinyl acetate homopolymer; carboxylated vinyl acetate polymers including copolymers of vinyl acetate and ethylenically unsaturated carboxylic acids, such as acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid and the like or anhydrides such as maleic anhydride; vinyl acetate / vinyl chloride / maleic acid terpolymer, and the like. Reference is made to U.S. Patent Nos. 3,718,714 and 4,284,746 and British Patent No. 1,361,841 for description of some of the low profile additives of suitable vinyl acetate polymers. The low profile additives of the vinyl acetate polymer ordinarily useful have molecular weights in the range of about 25,000 to about 175,000. Suitable low profile polyvinyl acetate additives are LP-40 and LP-40A which are sold by Union Carbide Chemical & Plastics Corp., Danbury, CT. Suitable low-modulus thermoplastic polyester additives are, in general, suitable low molecular weight polymers of polymerizable cyclic and / or linear esters and carboxylated saturated polymers and polymerizable esters having at least one carboxyl group per molecule. Linear and / or cyclic polymers including carboxylated polymers having at least an average of at least one carboxyl group per molecule that can be used in accordance with the present invention are those which have a reduced viscosity of at least about 0.1. , and preferably from about 0.15 to about 15 or more. Preferred cyclic ester polymers have approximately a reduced viscosity of about 0.2 to about 10. The well-known thermoplastic saturated linear and / or cyclic ester polymers and saturated carboxylated esters are well known and such thermoplastic saturated polymers and particularly prepared polymers of caprolactones epsilon have been used advantageously as low profile additives. The reference, for example, is made to U.S. Patent Nos. 3,549,585 and 3,668,178 for descriptions of low profile additives of saturated thermoplastic polyester and low profile additives of carboxylated thermoplastic saturated polyester prepared from cyclic esters. Other saturated thermoplastic polyesters which are useful as low profile additives are those based on condensation products of, primarily, dicarboxylic acids and organic diols. Some examples of such diacids are adipic acid, isophthalic acid, terephthalic acid and the like and such glycols can be ethylene glycol, diethylene glycol, neopentyl glycol and the like. Also suitable in certain aspects of the invention are the low profile additives of thermoplastic polyalkyl acrylates and methacrylates including, for example, homopolymers of methyl methacrylate, ethyl methacrylate, butyl methacrylate, methyl acrylate, ethyl acrylate; copolymers of methyl methacrylate and lower alkyl esters of acrylic and methacrylic acids, and copolymers of methyl methacrylate with minor amounts of one or more of the following: lauroyl methacrylate, isobornyl methacrylate, acrylamide, hydroxyethyl methacrylate, styrene, 2-ethylhexyl acrylate, acrylonitrile, methacrylic acid, polystyrene, styrene copolymers, such as styrene / butadiene copolymers, cellulose-butyrate acetate, alkylene oxide polymers, urethane polymers, and the like. The molecular weight of the acrylate or alkyl methacrylate polymers useful in the invention may vary over a range of 10,000 to 1,000,000 and preferably 25,000 to 500,000. The urethane polymers that can be employed in this invention, alone or as mixtures with other low profile additives are broadly structured and some examples are found in U.S. Patent Nos. 4,035,439; EP 74-746; and U.S. Patent No. 4,421,894. The low profile additives may be employed in the compositions of the invention in proportions of from about 1 to 25 percent by weight, and preferably from about 5 to 20 percent by weight in total base to the thermosetting resin, profile additive lower and other reactive components. The low profile additive can work alone or in combinations with other thickening agents such as a thickening contributor for resin flow characteristics. The thin film can be characterized as non-emptied. Optionally, the film can also be sticky. This condition can be achieved in a variety of ways. Many thermosetting resins are solid at about 23 ° C, and many of them are liquid at these temperatures. Both types of reams can be made fluid, non-empty and sticky. For example, a resin that is solid and a ream that is liquid can be combined to form a mixed ream system that is non-pourable and sticky. In addition a solid or liquid water-based thermoset resin may be incorporated in a variety of diverse materials that will carry the resin to the non-drainable fluid under conventional handling temperature conditions and a non-drainable, sticky fluid at room temperature (approximately 15-37). ° C). Conventional handling temperatures are defined as a temperature between about -20 ° C to about 43 ° C. Typical formulations of the invention are indicated in the following tables. A typical resin formulation comprises the following: Specific representative illustrations of such film formulations are the following: 7 This range reflects the fact that material handling may require low storage temperature to premix the reaction of the thermoset resin system and relatively high temperatures since the film can be used on a hot factor basis.

Notes: r ~ ~ (5) Resin Bis F, ["(9) Powder of { 13) I (1) Resin based j Daimppon In silica, Malvern 4, 4 diaminofenilsu 'Corp. lfona , Ciba Geigy Bis A, Chemical Co. f ~ (2) Resin Tr? s ~ (6) Amine ~ (10) Powder of ["(14) epoxy.Dow Chemical! aromatic (silica, Harbison (Diciandiamide, Air Co. , epoxidada, Ciba ¡alker, Producs i Geigy | | f ~ (3) Epoxy resin (7) Surfactant (11) Powder of (15) Dianhydride of ! Hardened, Dow Noionic, Monsanto (Silica, CE, Benzophenone, Chemical Co .. i Minerals, i (4) Novolac Phenol (8) Hardener, (12) Silica (16) Catalyst . epox dadi ABS, General, Smoked, Coal (from Electric,, Methylimidazolazma These resin formulations are made by conventional mixing of the components in standard mixing equipment for viscous compositions. Good results have been obtained using a RossR Double Planetary Mixer, provided with a vacuum and pack construction to control the temperature and aerate the mixture. Mixing is typically carried out by mixing the ream, unexpanded particles, elastomer components, extenders, diluents, curing agents and vacuum pumping to remove incoming air. The chosen temperature is variable depending on the viscosity of the formulation. It may be desirable to separately mix the resin and the curing agent. In such a case, the formulation can be divided until the resin is mixed with some portion of the formulation to effect a well dispersed condition and do the same with the curing agent, and then combine the well dispersed mixtures, to mix them all under conditions that avoid the premature reaction. Such procedures are well within the skill of the art. The following discussion relates to the drawings and figures shown here. None of the figures shows true dimensions of the various components represented therein. Figure 1 shows schematically the implementation of the film of the invention in the manufacture of an article removed from reliefs. Figure 1A shows a composite of a thin, unsecured film 11 superimposed on the solid substrate 12. The film 11 rests on the substrate 12. The substrate 12 can be any solid surface, such as steel, wood, thermoset plastic, a heated metal deposit, and the like. In a true application of the invention, the film 11 can be depicted much thinner than the one depicted.

Figure IB includes the features of Figure IA plus tool 13 with male molding surfaces 15 projecting from the tool surface 17 indicative of the printed circuit pattern for a printed circuit board. The tool 13 proved to be covered by heat or contain an electric heater within it, such that it can be used to effect the curing of the film 11 at the appropriate time. However, the tool 13 can be manufactured from a cured thermosetting resin, and in such an embodiment, it is unlikely to contain heating means. In the embodiment of Figure IB, Figure 11 rests on the solid substrate 12, and the tool 13 is superimposed on the film 11, in a position to be decreased in the film 11 or to have the substrate 12 in such a way that the film 11 is pushed into the surface of the tool 13 containing the molding surfaces 15. Alternatively, both the substrate 12 and the tools 13 can be moved to raise them and cause the surfaces 15 to remove the relief of the film 11. Either the tool 13 and the film 11, with or without the presence of the metal foil 14, is melted in such a way that the molding surfaces 15 penetrate directly or indirectly (i.e., via i? metal foil 14 of the ./investment relief), the surface of the film 11 not cured, the film 11 will produce the pressure imposed by the surfaces 15. Due to the thick nature of the film 11, the surface penetration of the film 11 will not radiate film flow out of the film area. 15 male surfaces. In its lur.ar, the displaced content of the film 11 will cause the rest of the film 11 to rise, in such a way that the surface 17 contacts the film 11. When the surface L7 comes into contact with the film 11, the Total pressure.-bet on film 11 will cause film 11 to expand in a super fi cial area. However, if the surfaces 15 quickly and rapidly penetrate the film 11, it is possible for the perforation to cause some small amount of the amount to flow so that it causes the film 1J to expand in a super fi cial area. From the foregoing, it is easily observed that the stravo 12 can be a stationary reservoir, a ds.i having an up and down movement, a moving table that results in a movement tool 13, a surface of ---.- and -.- Endless in Duride "the tool 13 is part of a drum or tool 13 of rotation and is fixed to a reservoir of gyratory reading, and the like.

Figure IC is another modality in which a sheet 14 metal is placed between the tool 13 and the film 11, and the superimposed metal sheet 14 rests on the adjacent surface of the film 11, which in turn is supported by the support 12. The metal sheet 14 can be manufactured from a variety of metals, as indicated above. The metal sheet 14 can be manufactured directly from the film 11 by a vapor deposition in line of a metal sheet 14 with a surface of the film 11. When it is desired that the metal sheet 14 be removed from the formed thermoset film 11, it is it prefers to coat its surface contacting the film 11 with a release agent, such as an organic release agent such as silicone or polyfluorinated. There are many types of release agents that are commercially available that will serve this purpose. Once the tool 13 is caused to conform the film 11, either as in the case shown in Figure IB or Figure IC, the shaping is caused primarily by projecting the surfaces 15 that penetrate the contiguous surface of the film 11. This causes the film 11 to respond to the penetration of the surfaces without materially increasing the density of the film 11 at the penetration points. Figure ID is a side view showing the result of such shaping action. In both embodiments as shown in Figures IB and IC, the resulting structure as shown in Figure ID contains notches 16 which are corresponding females to the male surfaces. In the situation where a composite formed is based on the use of the metal foil as shown in Figure IC, the resulting shaped structure will contain a foil layer which follows the grooved surface 16 of Figure ID. Where the metal sheet 14 contains a release agent, then the shaped metal sheet can be easily pulled from the surface of the formed film 11 leaving a printed circuit board substrate that can be deposited metal or the like, treated by conventional technologies, to generate the printed circuit board. The curing of the film 11 can take place while the surfaces 15 and 17 of the tool with or without the metal sheet 14 penetrate the contiguous surface of the film 11. In such an embodiment, the assembly of the tool 13, the film 11 and the substrate 12, with or without a metal foil 14, as shown in Figure 1C, can be placed in an oven and with the tool 13 adjoining the film 11 or the metal foil 14, or the film 1. Then, the tool 13 and the film 11 can be pressed in such a way that the pattern of the surfaces 15 is removed from the relief inside the film 11 and the composite is heated to effect the gelation or incipient gelation or total cure of the film 11. The The metal sheet 14 is part of the structure, as shown in Figure 1E, will result in a compound in which the metal sheet 21 is removed from relief within the film 11 to form notches 20 of the foil aligned. If the metal foil 14 does not contain a release agent, the adhesive nature of the film 11 will rigidly bond the metal foil 21 to the film 11. However, if it is desired to use the metal foil 14 as a shaping aid, then the metal foil 21 can be pulled that is in contact with the film 11 with the proviso that the release agent is provided on the side of the film 14 to make contact with the film 11. If it is desired to leave the metal foil 21 in contact with the film 11 then the composite can be subjected to an abrasion reaction to remove the metal foil from the surface 18 leaving the metal foil 21 in the notches 20 of the resulting printed circuit board. In the case where the metallic sheet 21 is left in the notches 20, it is not desirable to put a release agent on the surface of the metal sheet 14 that is contiguous with the film 11. In this case, in a preferred embodiment, it would be desirable to print the contiguous side of the metal sheet 14 with a pattern of the agent of release covering that corresponding to the pattern of the surface 18. In this form, the metal sheet 21 can be rubbed from the surface of the film 11 removed from the relief, as shown in Figure ID, in the majority thereof. way that the unbonded gold leaf is removed to make finished signs of gold leaf. The abrasion of the bonded metal sheet from non-concave surfaces and without cured film slots 11, can be performed by standard sand strips or wheels and high pressure water streams. The use of the metal sheet 14 in forming the printed circuit board can serve, as indicated above, for the function of transferring a metallic conductive film into the notches. The chips and other components of peripheral circuits, fixed to the PB can be connected by welding to the conductive film in the notches and cavities that form the PB. Sheet forming the resin formulation is a desirable way of manufacturing the thin films of the invention. This is illustrated in the drawings, as shown in Figure 2, which is a schematic illustration of a line 30 for forming sheets to form sheets of a conformable film. The feed 33 of the thermosetting matrix resin formulation is fed to Nip cylinders 31. The Nip cylinders 31 are sheet-forming cylinders separated from each other for the desired thickness of the film 37. It is desirable in the practice of the invention to avoid the design action of the film 37 after forming by the cylinders 31. The cylinders 31 they can vary in width, the larger cylinders generate higher productivity, and the narrower cylinders provide more control over the thickness of the film from edge to edge. Since this invention relates to films of essentially uniform thickness from edge to edge, horizontal to rear, it is necessary to use sheet forming rolls that are less than about 60 inches wide. A convenient width is approximately 40 to approximately 48 inches. The manufacture of films that meet the specifications of this invention is easier in those widths. Since the viscosity of the feed 33 is not excessive, the sheet forming operation can be observed as a film forming operation, akin to the coating of the cylinder. The distance between the rollers 31 is maintained by a force swing (not shown) between the hydraulic pressure pushing on the roller and the fluid balance of the die acting in the opposite direction to the cylinder. Once the film 27 is formed it is often desirable to increase the viscosity of the matrix resin in the film. Reducing the temperature of the film 37 increases the viscosity which reduces the flow within the film and thus helps preserve its dimensions. This can be accomplished by passing the film 37 over one or more cold cylinders. If cold cylinders are used. These are cooled typically and internally via the inner shell, for temperatures from about 0 ° C to about 25 ° C, preferably from about 10 ° C to about 16 ° C, sufficiently low to avoid any detachment or flow of the matrix of resin. The cold cylinders cool the film, increase the elastic modulus of the resin, in such a way that the flow of the resin decreases and the dimensional stability of the film is maintained. In the configuration of Figure 2, the laminator 35 can be used as a cold laminator, a guide laminator for alignment and / or alignment purposes as desired. For driving convenience, paper or plastic release layers (ie, polyethylene films) (not shown) can be applied to the outer surfaces of the film 37 from their corresponding core cylinders, to form a compressed construction. Continuous density measurements are taken at point 39 and weight measurements of the physical area are taken at point 41. The feedback of both measurements can be used to adjust the space between the cylinders 31 nip, thus controlling the thickness. Thickness control can be improved by the use of statistical process control to indicate when nip space adjustments are required. Figure 3, which relates to a prior art process for forming the flat PB board, describes uncoiled fiberglass fabrics from the cylinder 111 of fiberglass cloth, which passes the continuous sheet 113 of the fiberglass fabric in the ream step 115 via the guide mills 117, on a guide mill 119 and below a guide mill 121. The guide number shown is symbolic and not necessarily indicative of how the impregnation step of the resin is specifically carried out. Step 115 contains sufficient thermoset resin A graded to allow the desired impregnation of the fabric. The fabric removed from step 115 is fed through the compressible cylinders 123 fixed to the nip fabric 125 and reduce the level of the ream therein. The fabric 125, which contains the thermosetting resin A, is fed to the treater 127 which contains the heater 133. The fabric 125 is fed onto the guide laminator 129, the heater 133 passes and then on the guide laminator 131. In the treater 127, the polymerization of the graded resin A is initiated in such a way that the thermosetting resin in the fabric sheet 135 is transformed into a graded resin B. The prepreg sheet 135 is guided by the laminator 137 to the cylinder 139 of collection. The prepreg fabric 135 is in a separate station, unwound and cut to individual sized sheets 141. They are then superimposed to form a multilayer prelaminated stored structure 143 containing a copper metal foil on the outer top and bottom surfaces of the multiple superimposed prepreg sheets. The stored structure 143 is inserted into the laminator 145 which comprises a reservoir press that contains the upper heat reservoir 147 and the lower heat reservoir 149. With pressure and heat, typically around 350 ° F, the graded resin A is cured to form the metallized copper laminate 151. [See footnote 1 above] The laminate 151 is cut and sized to form finished laminates 153 which are then placed in the packages 155 and sent to the PB producer.

Claims (28)

1. CLAIMS 1. A thin, isotropic, dielectric thermoset resin film characterized in that a) it is formed by compression stamping and molding and with respect to it can be molded without obstructing the flow at the edges of the resin film; b) forms a thermofixed dielectric substrate; c) is sufficiently uniform in thickness to provide essential and consistently uniform heat forming capacity between the total film and the thickness is sufficient to accept the conformation imposed by the forming process; d) it has a low flow over a wide temperature range such that it does not flow uncontrollably while undergoing curing conditions, and when it is placed under pressure, only the portions that are superimposed on a notch or cavity in the case of a female mold, or on a protrusion in the case of a male mold, will cause it to flow due to the pressure imposed on the film; and e) gels or forms almost a gel under conditions that lead to curing that satisfies commercial conditions.
2. 2. The thin, isotropic, essentially non-conductive thermoset resin film according to claim 1, characterized in that the film comprises: (i) a thermoset resin that advances in molecular weight without forming a volatile significant product and (ii) a component of flow control.
3. 3. The thin, isotropic, essentially non-conductive thermoset resin film according to claim 1, characterized in that the film possesses a) a uniform area thickness in the range of about 1 to about 250 mil (approximately 0.0254 mm to about 6.35 mm) as calculated from the weight of the resin film for a given area; b) with minimum and maximum thickness that does not exceed the deviation factor indicated in Table A. Table A c) low flow over a wide temperature range; d) the ability to cure, gel, or near gelation, at temperatures from about 20 ° C to about 250 ° C, in less than about 7 days and more than 1 second; e) a low dielectric constant in the thermoformable state.
4. 4. The thin, isotropic, essentially non-conductive thermoset resin film according to claim 2, characterized in that the flow control component comprises one or more of i) one or more electronic grade fillers; ii) a thermoplastic resin that is soluble or partially soluble in the thermosetting resin; iii) an elastomer-type polymer that provides discrete elastomer phases, (secondary phase) in the thermosetting resin matrix; and iv) a thioxotrope;
5. 5. The thin, isotropic, essentially non-conductive thermoset resin film according to claim 1, characterized in that the film when cured is depositable as metal and adheres to a conductive metal film.
6. 6. The thin, isotropic, essentially non-conductive thermoset resin film according to claim 1, characterized in that the film is adhesively bonded to a metal foil and can be used to form a stamped surface or create a conductive path over a Cured and printed resin film.
7. 7. The thin, isotropic, essentially non-conductive thermoset resin film according to claim 1, characterized in that the film is shaped to contain notches suitable for use in manufacturing a conductive path in a printed circuit board.
8. 8. The thin-isotropic, essentially non-conductive thermoset resin film according to claim 1, characterized in that the thermosetting resin is an epoxy resin.
9. 9. The thin-isotropic, essentially non-conductive thermoset resin film according to claim 1, characterized in that the thermosetting resin is from the group consisting of bismaleimide, phenolic, polyester, PMR-15 polyimide, vinyl ester cyanate ester and acetylene finished in resins.
10. 10. The thermoset, thin, isotropic, essentially non-conductive resin film according to claim 9, characterized in that the thermosetting resin is a mixture of an epoxy resin and a cyanate resin.
11. 11. The thin isotropic, essentially non-conductive thermoset resin film according to claim 9, characterized in that the thermosetting resin is a vinyl ester resin.
12. 12. The thin, isotropic, essentially non-conductive thermoset resin film according to claim 4, characterized in that the flow control agent comprises an elastomer-type polymer.
13. 13. The thin, isotropic, essentially non-conductive thermoset resin film according to claim 4, characterized in that the flow control agent comprises a polyurethane.
14. 14. The thin, isotropic, essentially non-conductive thermoset resin film according to claim 13, characterized in that the flow control agent comprises a polyurethane containing uride linked to phenolic hydroxyl end groups.
15. 15. The thin, isotropic, essentially non-conductive thermoset resin film according to claim 1, characterized in that the resin contains expandable thermoplastic particles in situ.
16. 16. The thin, isotropic, essentially non-conductive thermoset resin film according to claim 1, characterized in that the resin contains a low profile additive.
17. 17. The thin, isotropic, essentially non-conductive thermoset resin film characterized in that it is manufactured by curing the thin, essentially non-conductive thermoset resin film according to claim 1.
18. 18. The thin isotropic thermoset resin film is essentially non-conductive. conductive, characterized in that it is manufactured by curing the thermoset, thin isotropic, essentially non-conductive resin film according to claim 2.
19. 19. The thin, isotropic, thermoset resin film is essentially non-conductive, characterized in that it is manufactured by curing the resin film thermofagged, thin isotropic, essentially non-conductive according to claim 23 20.
20. Thin, isotropic, essentially non-conductive thermoset resin film, characterized in that it is manufactured by curing the thermoset, thin isotropic resin film, essentially non-conductive in accordance with 4.
21. The thin, isotropic, essentially non-conductive thermoset resin film, characterized in that it is manufactured by curing the thin isotropic, essentially non-conductive thermoset resin film according to claim 1 and containing a film of thin metal sheet, adhesively bonded to it.
22. 22. The thin isotropic resin film, essentially non-conductive, characterized in that it is manufactured by curing the thin-isotropic, essentially non-conductive thermoset resin film according to claim 2 and containing a thin metal foil bonded in adhesive the same.
23. 23. The thin, isotropic, essentially non-conductive thermoset resin film characterized in that it is manufactured by curing the thermoset, thin isotropic, essentially non-conductive resin film according to claim 3 and containing a thin foil film bonded in the form adhesive to it.
24. 24. The thin, isotropic, essentially non-conductive thermoset resin film, characterized in that it is manufactured by curing the thermoset, thin isotropic, essentially non-conductive resin film according to claim 4 and containing a thin foil film bonded in the form adhesive to it.
25. 25. The thin, isotropic, essentially non-conductive thermoset resin film characterized in that it is manufactured by curing the thin-isotropic, essentially non-conductive thermoset resin film according to claim 21, wherein the metal foil is copper.
26. 26. The thin, isotropic, essentially non-conductive thermoset resin film, characterized in that it is manufactured by curing the thin-isotropic, essentially non-conductive thermoset resin film in accordance with claim 22, in which the metal sheet is copper.
27. 27. The thin, isotropic, essentially non-conductive thermoset resin film characterized in that it is manufactured by curing the thin isotropic, essentially non-conductive thermoset resin film according to claim 23, wherein the metal foil is copper.
28. 28. The thin, isotropic, essentially non-conductive thermoset resin film characterized in that it is manufactured by curing the thin-isotropic, essentially non-conductive thermoset resin film according to claim 24, wherein the metal foil is copper.