JPH09272176A - Production of metal foil polyimide laminated board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prepare in a short time and inexpensively a large amt. of high quality metal foil polyimide laminated boards by a method wherein metal foils are laminated through a polyimide layer dried with hot air in a hot-air drying oven and they are contact-bonded and laminated together by means of pressure rollers. SOLUTION: A copper foil 10 and a stainless steel thin sheet 11 between which a polyimide film 12 is placed are fed into a hot air drying oven 22 and they are contact-bonded by means of pressure rollers 20 and 21 but before that, as they are heated with dry hot air at 250 deg.C blown out from a hot air blowing apparatus and are dehumidified and dried, the copper foil 10 and the stainless steel thin sheet 11 are strongly bonded and laminated to obtain a continuous laminated board 1a, which is transferred to a width adjusting device 3. A shearing device 4 cuts a width-adjusted laminated sheet 1c forwarded from the width adjusting device 3 to a specified length by means of a cutter 40 and a number of metal foil polyimide laminated boards 1 with a definite length are forwarded outside.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for producing a metal foil-polyimide laminate comprising a metal foil layer and a polyimide layer.

[0002]

2. Description of the Related Art A metal foil-polyimide laminate made by laminating two metal foils via a polyimide layer is known, and is widely used because it is flexible, thin and lightweight, and tough. There is. Examples of use of this metal foil polyimide laminate include printed circuit boards, sheet heating elements, electromagnetic shield materials, suspension materials, flat cables, packaging materials and the like.

In the case of producing this conventionally known metal foil polyimide laminate, a polyimide varnish useful as an adhesive is applied to one of the metal foils to be bonded and dried, and then the metal foil coated with the adhesive is used. The other metal foil was sheared to a predetermined size, and after overlapping them, the product was obtained through a drying process and a vacuum pressing process. Further, as another manufacturing method, there is a method in which two metal foils and a polyimide film are each sheared to a predetermined size, and these are superposed, and then a product is obtained in the same manner as above.

However, in these manufacturing methods, it is difficult to automate the work of superposing two metal foils or polyimide films, and it depends on the manual work of a skilled worker so that the efficiency is low and the productivity is low. However, there is a problem in that the positioning accuracy is low, and that the rate of defective products due to cutting chips or dust being sandwiched between them at the time of superposition increases, resulting in an increase in manufacturing cost.

Further, according to the above manufacturing method, the moisture contained in the polyimide adhesive or the polyimide film is removed and the gas existing between the layers is removed by suction by a drying step and a vacuum pressing step prior to the curing of the polyimide adhesive or the polyimide film. Then, it was necessary to cure the polyimide layer and thereby strengthen the adhesive force. However, it is very inefficient to perform drying and removal of gas after stacking two metal foils via a polyimide layer, and it takes a long time for both of these steps, resulting in a long manufacturing time. There was a problem.

[0006]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to be carried out completely automatically or semi-automatically by a simple device. Another object of the present invention is to provide a method for producing a metal foil-polyimide laminate, which can provide a large amount of high-quality products at low cost in a short time with less manufacturing defects, requiring less labor.

[0007]

[Means for Solving the Problems] The above object is to dry a large number of long metal foils by sandwiching a polyimide layer, or by hot air drying so that one long metal foil and a long polyimide film are overlapped with each other. It is continuously supplied into the furnace to heat the polyimide,
After they are dried, they are pressure-bonded with a pressure roller provided in a hot-air drying furnace, the laminated sheet is sheared to a specified size, and a large number of these are stacked and pressed by a press,
This is achieved by increasing the flatness together with the adhesive strength.

When laminating the two metal foils described above, it is recommended that a polyimide film be sandwiched between the metal foils, but it is recommended that at least one of the opposing surfaces of the metal foils be laminated. It is also possible to apply a polyimide varnish, stack these metal foils, and press-bond them.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will be described below with reference to the drawings. FIG. 1 is an explanatory view for explaining an embodiment of a process sequence sequentially executed in the method of the present invention. In FIG. 1, 1
Is a metal foil polyimide laminated plate formed by stacking a copper foil 10 and a stainless steel thin plate 11 via a polyimide film 12, 2 is a roller pressure welding device, 3 is a width adjusting device, 4 is a shearing device, 5 is a pressing device, and 6 is It is an inspection device.

The polyimide film 12 is a high heat resistant polyimide film coated with thermoplastic polyimide on both sides. The copper foil 10, the stainless steel thin plate 11 and the polyimide film 12 are long ones, and they are wound up in advance to form the copper foil coil 100, the stainless steel thin plate coil 110 and the polyimide film roll 1, respectively.
I will set it to 20.

The roller pressure contact device 2 comprises a pair of pressure-bonding rollers 2 whose surfaces are coated with tetrachloroethylene resin.
It consists of a hot air drying oven 22 equipped with 0 and 21. Although not shown in the drawing, the copper foil coil 10 is provided outside the hot air drying furnace 22.
0, a device for mounting the stainless thin plate coil 110 and the polyimide film roll 120 is provided, and the copper foil 10 and the stainless thin plate 11 are the polyimide film 1
It is supplied to the hot-air drying oven 22 with 2 sandwiched between it and the pressure roller 2
Although it is pressure-bonded with 0 and 21, before that, it is heated by the dry hot air of 250 ° C. blown from a hot air blower (not shown), dehumidified and dried, so that the copper foil 10 and the stainless thin plate 11 are firmly bonded, The long laminated sheet 1a is laminated and sent to the width adjusting device 3.

The width adjusting device 3 draws the long laminated sheet 1a manufactured by the roller pressure welding device 2 into the inside, and trims the ridge 1b with the rotary cutter 30 to adjust the width of the laminated sheet 1a to a predetermined width. Width width laminated sheet 1c
And the cut-out pit 1b is collected. The width adjusting device 3 sucks the air around the rotary cutter 30 and prevents the cutting scraps of the rotary cutter 30 from adhering to the width adjusting laminated sheet 1c.
One. The shearing device 4 draws the width-adjusting laminated plate 1c sent from the width-adjusting device 3 into the inside, cuts it into a length specified by a cutter 40, and sends it out as a large number of metal foil polyimide laminated plates 1 of a fixed size. Like the width adjusting device 3, it has an air intake device 41 for removing cutting chips.

The pressing device 5 is held below the fixed heat plate 50a and a gate-shaped frame 50 for holding the fixed heat plate 50a so as to be movable in a vertical direction in parallel with each other and in a predetermined range. The three movable hot plates 51, 52, 53 and the elevating device 54 which is provided below the lowermost movable hot plate 53 and pushes the movable hot plate 53 upward with a pressure of 0.5 kg / cm ^2. To have.

Fixed hot plate 50a and movable hot plates 51, 52,
53 is maintained at 275 ° C. by a heating device (not shown). This pressing device 5 is a device for stacking a plurality of metal foil polyimide laminated plates 1 and arranging rubber mats on the upper and lower surfaces thereof and storing them in the respective gaps of the heating plates in three steps. By operating the elevating device 54 while heating, the metal foil polyimide laminate 1 is pressed by each hot plate. The inspection device 6 inspects the metal foil polyimide laminates 1 pressed by the pressing device 5 one by one, and separates defective products by a device (not shown). The metal foil polyimide laminate 1 thus obtained is suitable as a printed circuit board.

[0015]

Example 1 Using a coating machine, a commercially available copper-nickel alloy foil having a thickness of 18 μm was directly and uniformly cast by casting a polyamic acid solution and heated to remove the solvent of the polyamic acid solution. Imidize to obtain polyimide coated metal foil,
It was wound into a coil. The thickness of the polyimide-coated metal foil was 28 μm.

Using this polyimide-coated metal foil coil and a SUS304 foil coil having a thickness of 18 μm, the SUS304 foil was brought into contact with the polyimide layer side of the polyimide-coated metal foil and the temperature was 220 ° C. Laminated under the condition of pressure 20kgf / cm, sized and sheared, and pressed under the condition of 245 ° C and 75kg / cm ² for 1 hour,
A metal foil polyimide laminate was obtained. The peel strength of this metal foil polyimide laminate is 0.9 kgf / cm between the SUS304 layer and the polyimide layer, 0.5 kgf / cm between the copper-nickel alloy layer and the polyimide layer, and warps, twists, wrinkles, No defects such as scratches and dust were observed. 288 ° C, 6
No swelling or peeling was observed even after immersion in the solder bath for 0 second.

[0017]

Example 2 A commercial copper foil having a thickness of 18 μm was directly and evenly and continuously cast onto a commercially available 18 μm thick copper foil by a coating machine, and the solvent of the polyamic acid solution was removed by heating to remove the imide. To obtain a polyimide-coated metal foil, which was wound into two coils. The thickness of the polyimide-coated metal foil was 28 μm.

Using these two polyimide-coated metal foil coils, the respective polyimide layers are in contact,
A metal foil polyimide laminate was obtained in the same manner as in Example 1.
The peel strength of this metal foil polyimide laminate was 0.6 kgf / cm between any of the copper layers and the polyimide layer, and defects such as warpage, twisting, wrinkling, scratches and dust were not recognized. In addition, no blistering or peeling was observed at all after the solder bath immersion at 288 ° C. for 60 seconds.

[0019]

Example 3 Using a coating machine, a commercially available thickness of 12.5 μm
Polyimide film (trade name: Apical NPI, Kanegafuchi Chemical Co., Ltd.) is uniformly and continuously cast directly on both sides of the polyimide film, and heated to remove the solvent of the polyamic acid solution and to imidize it, and to lengthen it. To obtain a polyimide film, which was wound into a coil. The thickness of this processed polyimide film was 18 μm.

This polyimide film and a thickness of 18 μm
Using the copper-nickel alloy foil and the SUS304 foil having a thickness of 18 μm, the copper-nickel alloy foil and the SUS304 foil are overlapped with each other with the processed polyimide film interposed therebetween, and the metal foil-polyimide laminate is prepared in the same manner as in Example 1. Got The peel strength of this metal foil polyimide laminate is SUS304.
It was 0.9 kgf / cm between the layer and the polyimide layer, and 0.5 kgf / cm between the copper-nickel alloy layer and the polyimide layer, and defects such as warp, twist, wrinkle, scratch and dust were not recognized. In addition, no blistering or peeling was observed at all after the solder bath immersion at 288 ° C. for 60 seconds.

[0021]

[Example 4] Using a coating machine, a polyimide varnish was cast directly and continuously on both surfaces of a commercially available polyimide film having a thickness of 25 µm (trade name: UPILEX-S, Ube Industries) and heated. Then, the solvent of the polyimide varnish was removed and at the same time imidized to obtain a long-sized processed polyimide film, which was wound into a coil. The thickness of this processed polyimide film was 37 μm.

This polyimide film and a thickness of 18 μm
The beryllium copper alloy foil and the electrolytic copper foil having a thickness of 18 μm were used, and the beryllium copper alloy foil and the electrolytic copper foil were overlapped with each other with the processed polyimide film interposed therebetween. A laminated board was obtained. The peel strength of this metal foil polyimide laminate is 0.9 kgf / cm between the electrolytic copper layer and the polyimide layer, 0.4 kgf / cm between the beryllium copper alloy layer and the polyimide layer, and warps, twists, and wrinkles. ,
No defects such as scratches and dust were observed. Also, 288
No blistering or peeling was observed even after immersion in a solder bath at 60 ° C. for 60 seconds.

The gist of the present invention is to use a long material as a material to be used and to heat and dehumidify the polyimide to be used in a drying oven immediately before using it for bonding. Therefore, the present invention is not limited to the above examples, for example, the heating temperature and pressure in the roller pressure welding machine and the pressing device can be changed according to the composition of the polyimide used, and the surface of the pressure roller. One or both of the materials may be heat-resistant rubber or other materials, and the hot air drying furnace and the pressure roller may be separately provided. Further, when a product is manufactured by further pressing the flat plate-like laminated plate as described above, it is possible to omit the intermediate step and directly press the long laminated plate to form the product.

In the above embodiment, two metal foils are laminated with a polyimide layer interposed between them. However, if a polyimide film is laminated on one or both sides of one metal foil, three or more metal foils are laminated. The foil may be laminated via a polyimide layer, and when the polyamic acid solution is applied to the surface of the metal foil, several kinds of polyamic acid solutions having different properties may be applied in layers.

Further, as the material of the metal foil, for example,
Copper, iron, aluminum, nickel, beryllium, molybdenum,
Examples include chromium, zinc, lead, silver, gold, platinum, valladium and alloys thereof. These alloys are high tensile alloys,
Highly conductive alloys, high permeability alloys, lightweight alloys, shape memory alloys, etc. Further, the thicknesses of the metal foil and the polyimide layer are not limited to the above embodiments, and the present invention covers all modified embodiments that can be easily equivalent to those skilled in the art from the above description.

[0026]

Since the method for producing a metal foil polyimide laminate according to the present invention is constructed as described above, according to the present invention, regardless of the skill of the operator, it is possible to continuously obtain high quality. Can provide products.

[Brief description of drawings]

FIG. 1 is an explanatory diagram illustrating an example of a process sequence sequentially executed in a method of the present invention.

[Explanation of symbols]

 1 ... Metal foil polyimide laminate 1a ... Long laminate sheet 1b ... Mimi 1c ... Width-varying laminate sheet 10 ... Copper foil 100 ... Copper foil Coil 11 ・ ・ ・ ・ Stainless steel thin plate 110 ・ ・ ・ Stainless steel thin plate Coil 12 ・ ・ ・ ・ Polyimide film 120 ・ ・ ・ Polyimide film roll 2 ・ ・ ・ Roller pressure welding device 20 ・ ・ ・ ・ ・ ・ Crimping roller 21 ・ ・ ・Crimping roller 22 ··· Hot air drying furnace 3 ·· Width adjusting device 30 ··· Rotating cutter 31 ··· Intake device 4 ·· Shearing device 40 ··· Cutter 41 ·· ..Air intake device 5 ... Press device 50 ... Frame body 50a ... Fixed hot plate 51 ... Movable hot plate 52 ... Movable hot plate 53 ... Movable hot plate 54 ... Elevating device 6 ... Inspection device

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁶ Identification number Internal reference number FI technical display location // B29K 79:00 105: 06 (72) Inventor Koichi Aizawa 1190 Kasama-cho, Sakae-ku, Yokohama-shi, Kanagawa Mitsui Toatsu Chemicals Co., Ltd. (72) Inventor Shigeyuki Shishido 1190 Kasama-cho, Sakae-ku, Yokohama-shi, Kanagawa Mitsui Toatsu Chemicals Co., Ltd. (72) Keisho Tsushima 1190 Kasama-cho, Sakae-ku, Yokohama, Kanagawa Mitsui Toatsu Inside Chemical Co., Ltd.

Claims (9)

[Claims] 1. A method of manufacturing a metal foil polyimide laminate, which comprises sequentially performing the following steps (a) to (e). (A) At least one metal foil coil (100, 11
0) A number of steps for manufacturing. (B) The metal foil coil (1
00, 110) to draw out the metal foils (10, 11) from each other, and stack them in the hot-air drying oven (22) with a hot-air-dried polyimide layer therebetween, and rotate at least two pressure-bonding rollers (20, 21) crimping,
Laminating process for laminating. (C) A shearing step of obtaining the laminate (1) by cutting the long laminate sheet (1a) obtained by the above-mentioned laminating step into specified dimensions. (D) A finishing step of stacking a large number of laminated plates (1) of fixed size obtained by the shearing step and pressing to increase the adhesive strength and the flatness. 2. The laminating step comprises a step of applying a polyimide varnish to at least one of the opposing surfaces of the metal foil and drying it, and a step of laminating these metal foils and rotating them in a hot air drying oven by a pressure roller (20, 21). The method for producing a metal foil polyimide laminate according to claim 1, comprising a step of pressure bonding and laminating. 3. A lamination process, wherein a polyimide film (1) is provided between a plurality of metal foils (10, 11) to be superposed.
The method for producing a metal foil polyimide laminate according to claim 1, which comprises sandwiching 2) and pressing and laminating these with a pressing roller (20, 21) rotating in a hot air drying oven. 4. The method for producing a metal foil polyimide laminate according to claim 3, wherein the polyimide film (12) is a high heat resistant polyimide film provided with thermoplastic polyimide layers on both sides. 5. The method for producing a metal foil-polyimide laminate according to claim 1, including the step of providing a polyimide layer on the outer surface of the outermost metal foil. 6. A method for producing a metal foil polyimide laminate, which comprises sequentially performing the following steps (a) to (e). (A) A step of manufacturing one metal foil coil. (B) A step of producing a polyimide film roll. (C) A metal foil is drawn from the metal foil coil manufactured in the above step a, a polyimide film is pulled out from the polyimide film roll manufactured in the above step b, and the metal foil and the hot air dried polyimide film are superposed in a hot air drying oven. A laminating process in which at least two pressure rollers that combine and rotate are pressed and bonded. (D) A shearing step of cutting the long laminated sheet obtained by the above laminating step into specified dimensions to obtain a laminated board. (E) A finishing step of stacking a large number of fixed-size laminated plates obtained by the shearing step and pressing to increase the adhesive strength and the flatness. 7. A shearing step, a width-adjusting step of removing only the long laminated sheet (1a) obtained by the laminating step, and a laminate sheet (1c) adjusted to a predetermined width by the width-adjusting step. 7. A method for producing a metal foil polyimide laminate according to claim 1 or 6, further comprising a shearing step of cutting a large number of laminates (1) having a length specified by the above. 8. A pressure roller (2) in a hot air drying oven (22).
The method for producing a metal foil-polyimide laminate according to any one of claims 1 to 7, wherein at least one surface of (0, 21) is rubber. 9. A pressure roller (2) in a hot air drying oven (22).
The method for producing a metal foil polyimide laminate according to any one of claims 1 to 7, wherein at least one surface of (0, 21) is a tetrachloroethylene resin.