JP2007144799A - Method for processing substrate, and electronic apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for sticking a protective substrate suitably by removing bubbles from the stage of resin coating process. <P>SOLUTION: The method for processing the other side of a substrate (10) having one side provided with a plurality of structures (36) comprises a first step for coating one side of the substrate (10) with adhesive (400), a second step for applying a negative pressure and a positive pressure sequentially to the adhesive, a third step for arranging a protective substrate (420) on the adhesive, a fourth step for processing the other side of the substrate, and a fifth step for stripping the protective substrate (420) from the substrate. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method of processing the other side of a substrate having a structure provided on one side.

  In the manufacturing process of a microdevice based on a silicon substrate, when processing one side of the substrate into a predetermined pattern by a dry etching method or the like, irregularities are formed by providing structures on the other side of the substrate. There may be. In such a case, as a method of processing the one surface side while protecting the structure or the like, for example, in Japanese Patent Application Laid-Open No. 2005-191550 (Patent Document 1), a support substrate is first bonded to the other surface side. A method is disclosed in which the one surface side is processed and the support substrate is removed after the processing.

  In this method, the support substrate is bonded to a silicon substrate by applying an adhesive such as a resin, but bubbles easily enter such an adhesive. Bubbles in the adhesive can be ruptured in the vacuum process and cause damage to the substrate. Also, when processing such as dry etching is performed with a temperature increase, the substrate may be cooled at the same time, but bubbles in the adhesive hinder the transmission of temperature, causing unevenness in the temperature of the substrate, which is desired. It may not be possible to process the shape.

In order to prevent such a problem, a method is employed in which bubbles are prevented from entering by bonding the support substrate and the silicon substrate in a vacuum atmosphere. In addition, a method has been proposed in which a groove or a through hole is provided in the support substrate so that bubbles in the adhesive escape into the groove or are removed from the through hole.
JP 2005-191550 A

  However, the method of bonding the substrates in a vacuum atmosphere and the method of providing a groove or the like in the support substrate are not sufficient, and fine bubbles may remain in the adhesive. In particular, bubbles attached to the side surfaces of the structure remain in place and are difficult to remove from the adhesive. These fine bubbles can aggregate in the resin drying process and grow into larger bubbles, which can cause various problems.

  Accordingly, an object of the present invention is to provide a method of suitably bonding a protective substrate by removing bubbles from the resin coating step.

  In order to solve the above-described problem, a substrate processing method according to the present invention is a method of processing the other surface side of a substrate provided with a plurality of structures on one surface side. A first step of applying an adhesive on the surface side, a second step of sequentially applying a positive pressure and a negative pressure to the adhesive, a third step of disposing a protective substrate on the adhesive, and the other of the substrates And a fourth step of processing the surface side, and a fifth step of peeling the protective substrate from the substrate.

  According to such a configuration, in the second step, by applying a positive pressure to the adhesive, the adhesive is pushed into the recesses between the structures, and as a result, bubbles attached to the substrate surface, the side surfaces of the structure, etc. Is peeled off from the surface and floats in the adhesive. On the other hand, when a negative pressure is applied, the bubbles in the adhesive expand and the buoyancy increases, so the bubbles easily escape from the surface of the adhesive layer. Here, applying a positive pressure means exposing a substrate coated with an adhesive to a pressurized atmosphere (pressure higher than atmospheric pressure), and applying a negative pressure means that the substrate is exposed to a reduced-pressure atmosphere ( Exposure to a pressure lower than atmospheric pressure). The order and number of times of applying positive pressure and negative pressure are not particularly limited.

  In the second step, it is preferable to apply a negative pressure after applying a positive pressure. As a result, bubbles floating in the resin by the positive pressure can be efficiently removed from the surface of the resin film by the negative pressure.

  In the second step, it is also preferable to apply a positive pressure and a negative pressure to the adhesive alternately twice or more. Thereby, the amount of bubbles remaining in the resin can be further reduced.

  The application of the positive pressure in the second step is preferably performed by adding water vapor, the solvent vapor of the adhesive, and / or an inert gas into the sealed container. When the solvent vapor or water vapor of the adhesive is added, these vapors enter the adhesive to lower the viscosity and improve the effect of removing bubbles. If an inert gas is used, a positive pressure can be applied without reacting with the first substrate or the structure.

  In the present specification, the solvent of the adhesive means not only a liquid that dissolves the adhesive but also a dispersion medium when the adhesive disperses without dissolving.

  In the application of the negative pressure in the second step, it is preferable to add water vapor or an adhesive solvent vapor to the atmosphere. Thereby, it can prevent that the solvent of an adhesive evaporates and fluidity | liquidity is lost and adhesiveness falls.

  It is also preferable to irradiate the adhesive with ultrasonic waves after the second step and prior to the third step. Even with the irradiation of ultrasonic waves, the same effect as applying a positive pressure and a negative pressure to the resin can be obtained, and bubbles can be removed more completely.

  After the first step, it is also preferable to repeat the second step and ultrasonic irradiation to the adhesive until the adhesive has a required thickness, and then perform the third step. The thinner the adhesive layer, the easier it is to obtain the effects of applying positive pressure and negative pressure and removing bubbles by ultrasonic irradiation. Therefore, bubbles can be removed more effectively by reducing the amount of adhesive applied at one time and repeatedly removing and applying the bubbles.

  Prior to the first step, it is also preferable to deaerate the adhesive. That is, by removing air bubbles from the adhesive itself before applying to the first substrate, the air bubbles remaining in the adhesive can be reduced. Examples of the deaeration treatment of the adhesive include a method of irradiating the adhesive with ultrasonic waves and a method of exposing the adhesive to a vacuum atmosphere.

  It is also preferred that the adhesive contains a photosensitive component. Thereby, light can be irradiated and an adhesive bond layer can be processed into a desired shape. For example, if it is formed according to the unevenness of the substrate and processed so as to have a substantially uniform thickness, there are advantages that the protective substrate can be easily peeled and the temperature can be transmitted substantially uniformly.

  Moreover, this invention also provides an electronic device provided with the board | substrate manufactured by the manufacturing method of the board | substrate which concerns on this invention. Here, the electronic device includes a video camera, a television, a large screen, a mobile phone, a personal computer, a portable information device (so-called PDA), and other various devices.

  Hereinafter, a substrate processing method and an electronic device manufacturing method according to the present invention will be described in detail with reference to the drawings. In this embodiment, for the purpose of processing a flow path forming substrate used in an ink jet recording head, a support substrate is bonded to the base material of the flow path forming substrate by the substrate processing method according to the present invention.

<Inkjet recording head>
First, the configuration of an ink jet recording head manufactured using the substrate processing method according to the present invention will be described with reference to FIGS.

  FIG. 1 is an exploded perspective view showing an embodiment of an ink jet recording head, and FIG. 2 is a plan view and a cross-sectional view of the ink jet recording head shown in FIG. FIG. 3 is a schematic view showing an ink jet printer including the ink jet recording head 1 shown in FIG.

  Hereinafter, the head 1 will be described in detail with reference to FIGS. 1 and 2.

  As shown in FIGS. 1 and 2, the head 1 includes a nozzle plate 320, a flow path forming substrate 10, an elastic film 50, a piezoelectric element 300 provided on the elastic film 50, a reservoir forming substrate 30, And a drive IC 120 provided on the reservoir forming substrate 30. The head 1 constitutes a piezo jet head.

  In this embodiment, the flow path forming substrate 10 is composed of a silicon single crystal substrate having a plane orientation (110), but may be composed of a silicon single crystal substrate having a plane orientation (100). On one surface of the flow path forming substrate 10, an elastic film 50 having a thickness of about 1 to 2 μm made of silicon dioxide previously formed by thermal oxidation is provided. In the flow path forming substrate 10, individual (plural) ink chambers (pressure generation chambers) 12 are arranged in parallel in the width direction via side walls 11.

  Further, a communication portion 13 is formed in a region outside the ink chamber 12 in the longitudinal direction, and the communication portion 13 and each ink chamber 12 are communicated with each other via an ink supply path 14 provided in each ink chamber 12. Yes.

  The communication portion 13 constitutes a part of the reservoir 100 that functions as a common ink chamber that communicates with a reservoir portion 31 provided on a reservoir forming substrate 30 described later and supplies ink to the individual ink chambers 12.

  Further, the ink supply path 14 is formed with a narrower width than the ink chamber 12, and maintains a constant flow path resistance of ink flowing into the ink chamber 12 from the communication portion 13.

  Further, on the opening surface side of the flow path forming substrate 10, nozzles that communicate with each ink chamber 12 in the vicinity of the end of the ink chamber 12 opposite to the ink supply path 14 via the insulating film 51. Nozzle plates 320 each having holes 321 are fixed (adhered) via an adhesive, a heat-welded film, or the like.

  The nozzle plate 320 has a thickness of, for example, about 0.01 to 1 mm and a linear expansion coefficient of 300 ° C. or less, for example, about 2.5 to 4.5 [× 10 −6 / ° C.]. It is composed of a silicon single crystal substrate or non-rust steel.

  On the other hand, the elastic film 50 having a thickness of, for example, about 1.0 μm is provided on the surface opposite to the opening surface of the flow path forming substrate 10 as described above. On the elastic film 50, an insulator film 55 having a thickness of about 0.4 μm, for example, is formed. Further, on the insulator film 55, a lower electrode film 60 having a thickness of, for example, about 0.2 μm, a piezoelectric layer 70 having a thickness of, for example, about 1.0 μm, and a thickness of, for example, about 0.1 μm. The upper electrode film 80 of about 05 μm is laminated in this order to form a piezoelectric element (driving element) 300 that controls the discharge of droplets. That is, the piezoelectric element 300 refers to a portion including the lower electrode film 60, the piezoelectric layer 70, and the upper electrode film 80.

  In the present embodiment, the lower electrode film 60 is formed as a common electrode of the piezoelectric element 300, and the upper electrode film 80 is patterned as a separate electrode of the piezoelectric element 300 along with the piezoelectric layer 70 at a position corresponding to each ink chamber 12 ( Formed). A portion that is constituted by the upper electrode film 80 and the piezoelectric layer 70 and in which piezoelectric distortion is generated by applying a voltage to both electrodes is referred to as a piezoelectric active portion. Also, the piezoelectric element 300 and a vibration plate that is displaced by driving the piezoelectric element 300 are referred to as a piezoelectric actuator.

  Generally, any one of the lower electrode film 60 and the upper electrode film 80 is configured as a common electrode, and the other electrode and the piezoelectric layer 70 are configured by patterning in each ink chamber 12. In addition, the configuration of the lower electrode film 60 and the upper electrode film 80 may be reversed for the convenience of the drive circuit and wiring. In either case, a piezoelectric active part is formed corresponding to each ink chamber 12.

  In this embodiment, the elastic film 50 and the insulator film 55 act as a diaphragm, but the lower electrode film 60 formed on the insulator film 55 also serves as a diaphragm. The lower electrode film 60 is patterned inside a region facing the ink chamber 12 with respect to the longitudinal direction of the ink chamber 12, and is continuously provided in a region corresponding to the plurality of ink chambers 12.

  The lower electrode film 60 extends to the vicinity of the end of the flow path forming substrate 10 in the region outside the row of the ink chambers 12. And the front-end | tip part comprises the connection part 60a which connects the connection wiring 130 extended from the drive IC120 mentioned later.

  The piezoelectric layer 70 and the upper electrode film 80 are basically provided in a region facing the ink chamber 12, but extend in the longitudinal direction of the ink chamber 12 to the outside of the region facing the ink chamber 12. The end surface of the lower electrode film 60 on the nozzle hole 321 side is covered with the piezoelectric layer 70.

  A lead electrode 90 is connected to the vicinity of the end of the upper electrode film 80 on the nozzle hole 321 side. The lead electrode 90 extends to the vicinity of the end of the flow path forming substrate 10, and the tip of the lead electrode 90 constitutes a connection portion 90 a for connecting the connection wiring 130, similarly to the connection portion 60 a of the lower electrode film 60. is doing.

  Further, the surface side of the flow path forming substrate 10 on which the piezoelectric element 300 is provided and the reservoir forming substrate 30 including the reservoir portion 31 that constitutes a part of the reservoir 100 are, for example, an epoxy-based adhesive It is bonded (fixed) through an adhesive layer 35 composed of the bonding agent 35a.

  In the present embodiment, the reservoir portion 31 penetrates in the thickness direction of the reservoir forming substrate 30 and is formed across the width direction of the ink chamber 12, and as described above, the communicating portion of the flow path forming substrate 10 13, the reservoir 100 of each ink chamber 12 is configured.

  In the present embodiment, the case where the flow path forming substrate 10 and the reservoir forming substrate 30 are bonded by the adhesive layer 35 has been described. However, the present invention is not limited to such a case, and these are made of a metal having adhesiveness. The substrates may be bonded (metal bonding).

  In addition, the opening peripheral portion on the reservoir portion 31 side of the penetrating portion 110 communicating with the communication portion 13 and the reservoir portion 31 and the opening peripheral portion of the reservoir portion 31 of the reservoir forming substrate 30 are adhered by the adhesive layer 35. The inner edge portion (inner surface) of the penetrating portion 110 is completely covered with the adhesive layer 35.

  The penetrating portion 110 is provided by penetrating the elastic film 50, the insulator film 55, and the lower electrode film 60 in the region facing the communicating portion 13 in the thickness direction.

  That is, the through portion 110 includes the first through hole 111 provided by penetrating the elastic film 50, the second through hole 112 provided by penetrating the insulator film 55, and the lower electrode film 60. And a third through-hole 113 provided by penetrating through.

  Then, the ink in the reservoir unit 31 is supplied to the communication unit 13 through the penetration unit 110.

  In addition, a piezoelectric element holding portion 32 that can secure a space that does not inhibit the vibration of the piezoelectric element 300 is provided in a region facing the piezoelectric element 300 of the reservoir forming substrate 30.

  Since the piezoelectric element 300 is provided in the piezoelectric element holding portion 32, the piezoelectric element 300 is protected in a state hardly affected by the external environment.

  Examples of the constituent material of the reservoir forming substrate 30 include glass, ceramic material, metal, resin, and the like. Among these, the constituent material is substantially the same as the thermal expansion coefficient of the flow path forming substrate 10. It is preferable that the same material as that of the flow path forming substrate 10, that is, the silicon single crystal in the present embodiment is more preferable.

  Further, the connection part 60 a of the lower electrode film 60 and the connection part 90 a of the lead electrode 90 are provided outside the piezoelectric element holding part 32. One end of a connection wiring 130 extending from the drive IC 120 mounted on the reservoir forming substrate 30 is connected to the connection portion 60a and the connection portion 90a. Further, a compliance substrate 40 including a sealing film 41 and a fixing plate 42 is bonded onto the reservoir forming substrate 30.

  The sealing film 41 is made of a material having low rigidity and flexibility such as a polyphenylene sulfide (PPS) film having a thickness of, for example, about 6 μm. The sealing film 41 and the communication part 13 of the reservoir part 31 are formed by the sealing film 41. The surface opposite to the communicating side is sealed.

  The fixing plate 42 is made of a hard material such as a metal such as stainless steel (SUS) having a thickness of about 30 μm, for example. Since the region of the fixing plate 42 that faces the reservoir 100 is an opening 43 that is completely removed in the thickness direction, the reservoir 100 is sealed only with a flexible sealing film 41. .

  In such a head 1, after taking ink from an external ink supply unit (not shown) and filling the interior from the reservoir 100 to the nozzle hole 321 with ink, the head 1 corresponds to each ink chamber 12 by a recording signal from the drive IC 120. A voltage is applied between each lower electrode film 60 and upper electrode film 80. As a result, the elastic film 50, the insulator film 55, the lower electrode film 60, and the piezoelectric layer 70 are deflected, that is, the diaphragm is deflected, whereby the pressure in each ink chamber 12 is instantaneously increased. As a result, ink droplets are ejected from the nozzle holes 321.

  When the ejection of one ink is completed, the driving IC 120 stops applying the voltage between the lower electrode film 60 and the upper electrode film 80. As a result, the piezoelectric element 300 almost returns to its original shape, and the volume of the ink chamber 12 increases. At this time, pressure (pressure in the positive direction) from the ink cartridge 231 toward the nozzle hole 321 is applied to the ink. For this reason, air is prevented from entering the ink chamber 12 from the nozzle hole 321, and an amount of ink corresponding to the amount of ink discharged is supplied from the ink cartridge 931 (reservoir 100) to the ink chamber 12.

In this way, by applying a voltage to the piezoelectric element 300 at the position to be printed in the head 1 via the driving IC, that is, by sequentially inputting the ejection signal, any desired (desired) character or figure Etc. can be printed.

The head 1 is not limited to the one having the above-described configuration. For example, the head 1 includes a heater instead of the piezoelectric element 300 as a driving element, and the ink is heated to boil by the heater, and the ink is generated by the pressure generated thereby. Or the like may be discharged from the nozzle hole 321 as a droplet.
<Method for Manufacturing Inkjet Recording Head 1>
Next, a process for manufacturing such a head 1 using the substrate processing method according to the present invention will be described.

  4 to 8 are views (longitudinal sectional views) for explaining a method of manufacturing the ink jet recording head shown in FIGS. 1 and 2, respectively.

  In this embodiment, a silicon single crystal substrate having a plane orientation (110) that can be dry-etched is used as the flow path forming substrate 10, but a silicon single crystal substrate having a plane orientation (100) is used. May be.

  [1] First, as shown in FIG. 4A, the silicon dioxide constituting the elastic film 50 and the oxide film 51 on the surface of the flow path forming substrate 10 by thermally oxidizing the flow path forming substrate 10 in a diffusion furnace. A film 52 is formed.

  The temperature of the atmosphere when the surface of the flow path forming substrate 10 is thermally oxidized is preferably about 800 to 1500 ° C, and more preferably about 1000 to 1200 ° C.

  [2] Next, as shown in FIG. 4B, for example, a zirconium (Zr) layer is formed on the elastic film 50 (silicon dioxide film 52), and then thermally oxidized in a diffusion furnace to form zirconium oxide. An insulator film 55 made of (ZrO2) is formed.

  The temperature of the atmosphere when thermally oxidizing the zirconium layer is preferably about 500 to 1200 ° C., more preferably about 600 to 900 ° C.

  [3] Next, as illustrated in FIG. 4C, a metal body such as platinum and iridium is stacked in this order on the insulator film 55 to form a stacked body.

  Thereafter, the lower electrode film 60 is formed by patterning the laminated body into a predetermined shape.

  For the lamination of these metal materials, for example, chemical vapor deposition (CVD) such as plasma CVD, thermal CVD, and laser CVD, vacuum deposition, sputtering (low temperature sputtering), dry plating methods such as ion plating, electrolysis, etc. Wet plating methods such as plating and electroless plating, thermal spraying methods, sol-gel methods, MOD methods, and the like can be used.

  In addition, for the patterning of the laminate, for example, one or two of physical etching methods such as dry etching, reactive ion etching, beam etching, and optically assisted etching, and chemical etching methods such as wet etching are used. A combination of the above can be used.

  When the lower electrode film 60 is formed, the third through hole 113 is formed by removing the portion of the stacked body that faces (contacts) the region where the communication portion 13 of the flow path forming substrate 10 is formed. Keep it.

  [4] Next, as shown in FIG. 4D, for example, a first metal layer 70 ′ made of lead zirconate titanate (PZT) or the like, and a second metal made of iridium or the like, for example. The metal layer 80 ′ is sequentially laminated on the entire surface on one side of the flow path forming substrate 10.

  Then, as shown in FIG. 4E, the laminated first metal layer 70 ′ and second metal layer 80 ′ are patterned so as to correspond to the positions of the ink chambers 12 described later, and the piezoelectric body. The layer 70 and the upper electrode film 80 are formed to obtain the piezoelectric element 300.

The formation of the first metal layer 70 ′ and the second metal layer 80 ′, and the first metal layer 7
For the patterning of the 0 ′ and the second metal layer 80 ′, the same method as described in the patterning of the laminate in the step [3] can be used.

  [5] Next, the lead electrode 90 is formed.

  Specifically, as shown in FIG. 5A, for example, adhesion such as titanium tungsten (TiW) or nickel chrome (NiCr) is provided over the entire surface on one side of the flow path forming substrate 10. An adhesion layer 91 made of a metal is formed, and a metal layer 92 made of, for example, gold (Au) is formed on the entire surface of the adhesion layer 91.

  Then, as shown in FIG. 5B, the adhesion layer 91 and the metal layer 92 are patterned so as to correspond to the piezoelectric elements 300 to form the lead electrodes 90.

  For the formation of the adhesion layer 91 and the metal layer 92 and the patterning of the lead electrode 90, the same method as described in the layering of the metal material and the patterning of the layered body in the step [3] is used. Can do.

  [6] Next, the penetration part 110 is formed.

  Specifically, as shown in FIG. 5C, first, a portion facing the region where the communication portion 13 is formed, that is, the insulator film 55 exposed in the third through hole 113 is removed. A second through hole 112 is formed.

  Next, the elastic film 50 exposed in the second through hole 112 is removed to form the first through hole 111.

  Thereby, the penetration part 110 which is constituted by the first to third through holes 111, 112 and 113 and has a stepped edge part is formed.

  For removing the insulator film 55 and the elastic film 50, the same method as described in the patterning of the laminate in the step [3] can be used.

  [7] Next, as shown in FIG. 5D, the surface of the flow path forming substrate 10 on the side where the piezoelectric element 300 is provided and the reservoir forming substrate 30 are bonded together by a bonding agent 35a.

  Thereby, the adhesive bond layer 35 comprised by the junction part agent 35a is formed in the edge part inside the penetration part 110. As shown in FIG. As a result, the flow path forming substrate 10 and the reservoir forming substrate 30 are bonded via the adhesive layer 35.

[8] Substrate Bonding Step Next, a process for forming the ink chamber 12 and the concave portion constituted by the ink supply path 14 and the communication portion 13 is performed on the flow path forming substrate 10 by using a dry etching method. . For this processing (etching), the substrate processing method of the present invention is applied (hereinafter, the ink chamber 12, the ink supply path 14, and the communication portion 13 are collectively referred to as "ink channel"). There is also.)

  That is, the flow path forming substrate 10 is provided with a structure 36 including the elastic film 50, the insulator film 55, the reservoir forming substrate 30 and the like on one surface side, and the other surface side is processed. Therefore, in accordance with the substrate processing method according to the present invention, the protective substrate is bonded to the one surface side and processed, and the protective substrate is peeled off after the processing.

  FIG. 6 shows a process of bonding the flow path forming substrate 10 and the protective substrate 39 upside down with respect to FIG. 5D for convenience of explanation.

  First, as a first step of the present invention, as shown in FIG. 6A, a resin 400 is applied as an adhesive to the surface of the flow path forming substrate 10 on which the structure such as the reservoir forming substrate 30 is provided. To do. The resin 400 is not particularly limited as long as it can adhere both substrates. For example, an aromatic resin such as polyimide resin, polyparaxylylene, benzocyclobutene, polyvinylphenol, and novolak resin, polytetrafluoro Fluorine resins such as ethylene (PTFE), acrylic resins such as polymethyl methacrylate (PMMA), polyolefin resins such as polyethylene, polypropylene, polyisobutylene, and polybutene, polyamide resins, etc. And a positive resist material.

  If a photosensitive material such as a resist material is used, the adhesive layer can be formed into a desired shape after being applied. In this embodiment, such a photosensitive resin is used. Photosensitive resins include negative resist materials, rosin-bichromate, polyvinyl alcohol (PVA) -bichromate, shellac-bichromate, casein-bichromate, PVA-diazo, Water-soluble photoresists such as acrylic photoresists, polyvinyl cinnamate, cyclized rubber-azide, polyvinyl cinnamylidene acetate, oil-soluble photoresists such as polycinnamic acid β-vinyloxyethyl ester, etc. As a positive resist material, an oil-soluble photoresist such as o-naphthoquinonediazide can be used.

  The above-described resin is appropriately dissolved (or dispersed) in a solvent (including a dispersion medium) as necessary and used for coating. Specific examples of the solvent include, for example, inorganic solvents such as nitric acid, sulfuric acid, ammonia, hydrogen peroxide, water, carbon disulfide, carbon tetrachloride, ethylene carbonate, methyl ethyl ketone (MEK), acetone, diethyl ketone, methyl isobutyl ketone. (MIBK), ketone solvents such as methyl isopropyl ketone (MIPK), cyclohexanone, alcohol solvents such as methanol, ethanol, isopropanol, ethylene glycol, diethylene glycol (DEG), glycerin, diethyl ether, diisopropyl ether, 1,2-dimethoxy Ethane (DME), 1,4-dioxane, tetrahydrofuran (THF), tetrahydropyran (THP), anisole, diethylene glycol dimethyl ether (diglyme), diethylene glycol ethyl Ether solvents such as ether (carbitol), cellosolv solvents such as methyl cellosolve, ethyl cellosolve, phenyl cellosolve, aliphatic hydrocarbon solvents such as hexane, pentane, heptane and cyclohexane, aromatics such as toluene, xylene and benzene Hydrocarbon solvents, aromatic heterocyclic compounds such as pyridine, pyrazine, furan, pyrrole, thiophene and methylpyrrolidone, amides such as N, N-dimethylformamide (DMF) and N, N-dimethylacetamide (DMA) Solvents, halogen compound solvents such as dichloromethane, chloroform, 1,2-dichloroethane, ester solvents such as ethyl acetate, methyl acetate, ethyl formate, sulfur compound solvents such as dimethyl sulfoxide (DMSO), sulfolane, acetonitrile, propio Nitrile Nitriles such as acrylonitrile, formic acid, acetic acid, trichloroacetic acid, various organic solvents such as an organic acid solvents such as trifluoroacetic acid, or mixed solvents containing them.

  The resin solution and resin dispersion obtained by dissolving (or dispersing) the resin in a solvent are prepared by a known method such as spin coating, spray coating, scan coating, or squeegee coating. Can be applied.

  FIG. 6A shows how the resin 400 is applied to the surface of the flow path forming substrate 10 by these methods. Bubbles A are contained in the resin 400, and in particular, the bubbles A attached to the structure 36 such as the reservoir forming substrate 30 are unlikely to be separated from the structure and are not easily released from the resin.

  Therefore, in this embodiment, a positive pressure is first applied to the resin 400 as the second step of the present invention. The application of the positive pressure can be performed, for example, by increasing the atmospheric pressure in the sealed container on which the flow path forming substrate 10 is placed. In order to increase the atmospheric pressure in the container, it is preferable to add water vapor, vapor of the solvent or dispersion medium of the resin 400, or an inert gas such as argon, helium, or nitrogen. If the solvent of the resin 400 or the vapor or water vapor of the dispersion medium is added, these vapors enter the resin 400 to reduce the viscosity, so that the effect of removing bubbles can be further improved.

  FIG. 6B shows a state where a positive pressure is applied. As a result of the positive pressure being applied, the resin 400 is pushed into the recesses between the structures 36, so that the bubbles A are peeled off from the structure such as the reservoir forming substrate 30 and float in the resin 400.

  Subsequently, as shown in FIG. 6C, a negative pressure is applied to the resin 400. When a negative pressure is applied, the bubbles A that have floated in the resin 400 are expanded and the buoyancy thereof is increased. Therefore, it is possible to facilitate the bubbles A to be lifted and released from the surface of the resin 400 into the atmosphere. The application of the negative pressure can be performed, for example, by discharging the gas from the sealed container and reducing the atmospheric pressure, contrary to the application of the positive pressure. Note that it is desirable to supply the vapor of the solvent of the resin 400 within a range in which the atmospheric pressure is not increased even during application of the negative pressure. By doing so, it is possible to prevent the solvent of the resin 400 from evaporating and losing fluidity.

  In the present embodiment, the negative pressure is applied after the application of the positive pressure. However, the application of the positive pressure and the negative pressure may be repeated, or the negative pressure may be applied first.

  After applying positive pressure and negative pressure, the resin 400 may be irradiated with ultrasonic waves. By performing such a treatment, bubbles in the resin 400 can be further reduced. In addition, the deaeration treatment of the resin 400 may be performed before coating on the flow path forming substrate 10. The deaeration treatment can be performed by, for example, irradiating the resin 400 with ultrasonic waves or exposing the resin 400 to a vacuum atmosphere. Even by such pretreatment, the number of bubbles in the resin 400 can be further reduced.

  In this embodiment, the application of the resin 400 is performed only once, but the resin 400 may be repeated little by little. In this case, application of the resin 400 and application of positive pressure and negative pressure are set as one set, and this set is repeated until the resin 400 has a required thickness. Removal of bubbles by applying positive pressure and negative pressure is more effective as the resin 400 is thinner. Therefore, by applying the resin 400 in multiple steps, it is possible to reduce the number of bubbles remaining in the resin 400. It is.

[9] Resin Molding Step Next, as shown in FIG. 7, a resin 400 is molded. If the recesses between the structures 36 are filled with the resin 400, there is a problem that the resin layer becomes thick only in this region, making it difficult to remove the resin and preventing the temperature from being transmitted. Therefore, in the present molding, the resin 400 is made to be the flow path forming substrate for the purpose of facilitating removal of the resin 400 after the processing of the flow path forming substrate 10 and uniformizing the temperature transfer to the flow path forming substrate 10. The thickness is approximately uniform along the shape of the 10 surface.

  First, as shown in FIG. 7A, light is irradiated onto the resin 400 in the direction of the arrow through a mask 410. As described above, in this embodiment, since a resist material having photosensitivity is used as the resin 400, by developing after irradiation with light, a recess is formed in the resin 400 as shown in FIG. 411 is formed. As a result, the resin 400 has a substantially uniform thickness along the surface of the flow path forming substrate 10 having irregularities due to the structure such as the reservoir forming substrate 30.

  Subsequently, as shown in FIG. 7C, as a third step of the present invention, a support substrate 420 is overlaid and bonded onto the resin 400. A through hole 422 is formed in the support substrate 420 at the position of the recess 411 formed in the resin 400. When there is no through hole 422, the recess 411 is sealed, and when it is placed under vacuum in the subsequent dry etching process, the air in the recess 411 may expand and the base material 10 ′ may be damaged. When the concave portion 411 is formed after the three steps, the through hole 422 is necessary. If the through hole 422 is provided, since the inside of the recess 411 is also cooled through the through hole 422 when cooling from the support substrate 420 side, an effect that the flow path forming substrate 10 can be easily cooled uniformly is also obtained.

[10] Mask Formation Step Next, as shown in FIG. 8A, as a fourth step of the present invention, in the region where the ink chamber 12, the communication portion 13, and the ink supply path 14 are formed on the oxide film 51. A resist layer (mask) 56 having a corresponding opening is formed. The resist layer 56 can be obtained by, for example, a photolithography method.

  Specifically, after a resist material is applied (supplied) onto the oxide film 51, the resist material is applied to the i-line via a photomask corresponding to the shapes of the ink chamber 12, the communication portion 13, and the ink supply path 14. It can be obtained by exposure and development with ultraviolet rays, electron beams or the like.

  As the resist material and the method for applying the resist material, the same methods as those for applying the resist material and the solution or dispersion containing the resin material described above can be used.

  In the present embodiment, the case where the resist layer 56 is composed of a resist material as a main material has been described. However, the present invention is not limited to such a case. For example, the resist layer is a metal layer as a lower layer of the resist layer 56. The laminated body provided with may be sufficient.

  Thus, in the next process, when the ink flow path is formed by the dry etching method using the resist layer as a mask, the resist layer is also etched as the flow path forming substrate 10 is etched (processed). It is possible to prevent or suppress the ink flow more suitably and form an ink flow path with more excellent dimensional accuracy. Examples of such a metal layer include a layer mainly composed of at least one of Al, Cu, Fe, Ni, and Cr. The metal layer is formed by forming a metal film on almost the entire surface of the oxide film 51, forming a resist layer 56 on the metal film by the method described above, and then using the resist layer 56 as a mask. This metal film can be obtained by etching into the same shape as the resist layer 56 by an etching method.

  Examples of the etching solution used in the wet etching method include an aqueous solution of an alkali metal hydroxide such as NaOH and KOH, an aqueous solution of an alkaline earth metal hydroxide such as Mg (OH) 2, and tetramethylammonium hydro Examples include aqueous solutions of oxides, amide-based organic solvents such as N, N-dimethylformamide (DMF), N, N-dimethylacetamide (DMA), and the like. These can be used alone or in combination.

[10] Etching Step Next, as shown in FIG. 8B, when the substrate 10 is cooled by spraying a cooling medium gas from the lower side of the flow path forming substrate 10, that is, from the lower side of the resin 400, The ink chamber 12, the communication portion 13, and the ink are formed on the upper surface of the flow path forming substrate 10 by using a dry etching method while reducing or preventing the occurrence of temperature unevenness in the flow path forming substrate 10 due to the presence. A recess formed by the supply unit 14 is formed.

  In the present embodiment, since the through portion 110 is provided in a region facing the communication portion 13 of the diaphragm, when the communication portion 13 is formed by this dry etching, the communication is made via the through portion 110. The reservoir 100 is formed by the communication between the portion 13 and the reservoir portion 31.

  The dry etching method includes a chamber, a first introduction valve for introducing a plasma generating gas into the chamber, a second introduction valve for introducing a cooling medium gas for cooling the flow path forming substrate 10, A pair of electrodes provided to face the inside of the chamber, a cooling plate that cools the flow path forming substrate 10 installed on one electrode side through a communication hole through which a cooling medium gas can pass, and the flow path forming substrate 10 This is performed using a dry etching apparatus provided with an installation base for fixing.

  That is, in the dry etching method, the substrate 10 is set on an installation table provided on the electrode side so that one electrode and the structure 36 face each other, and the inside of the chamber is decompressed. Then, the cooling medium gas introduced from the second introduction valve is sprayed to the lower side of the flow path forming substrate 10 to transmit the temperature of the cooling plate and the cooling medium gas to cool, and the plasma introduced from the first introduction valve A high frequency voltage is applied between the electrodes in a state where the gas for generation is supplied between the pair of electrodes. As a result, plasma is generated between the electrodes, and ions and electrons generated thereby collide with the upper surface of the flow path forming substrate 10 including the resist layer 56, thereby forming the ink chamber 12 and the recess (ink flow path). Is done.

Examples of the plasma generating gas include a fluorine-based gas, a halogen-based gas containing at least one of chlorine and bromine, and the substrate 10 is composed of a silicon single crystal as in this embodiment. In this case, it is preferable to use SF ₆ , C ₄ F ₈ , CBrF ₃ , CF ₄ / O ₂ , Cl ₂ , SF ₆ / N ₂ / Ar, BCl ₂ / Cl ₂ / Ar gas, particularly SF _6. And C ₄ F ₈ gas are used alone or a mixed gas thereof is preferably used. Thereby, the flow path forming substrate 10 can be etched efficiently.

  The cooling medium gas is not particularly limited as long as it has excellent cooling efficiency and does not affect the generation of plasma. For example, an inert gas such as helium, argon, nitrogen, etc. Among these, it is preferable to use helium as a main component. Helium is preferably used as a cooling medium gas because it has a particularly excellent cooling effect.

  Further, the temperature of the cooling plate, that is, the temperature of the cooling medium gas is preferably about −20 to 60 ° C., and more preferably about −10 to 10 ° C. Thereby, it becomes possible to cool the flow path forming substrate 10 and maintain an appropriate temperature.

[11] Removal Step Next, as shown in FIG. 8C, as a fifth step of the present invention, the resist layer 56 and the resin 400 are removed simultaneously or individually.

  In addition, as the constituent material of the resist layer 56 and the constituent material of the resin 400, among those described above, when the same or the same chemical properties are selected, the resist layer 56 and resin 400 can be removed simultaneously.

  The removal of the resist layer 56 and the resin 400 is performed by, for example, exposing to oxygen plasma or ozone vapor under atmospheric pressure or reduced pressure, or resist stripping solution such as acetone or alkylbenzene sulfonic acid that can dissolve them. It is possible to perform the process by liquefying all or a part of the resist layer 56 and the resin 400.

[12] Nozzle Plate Joining Step Next, the nozzle plate 320 provided with a plurality of nozzle holes 321 for ejecting ink as droplets is joined to the other surface side of the substrate 10 through the oxide film 51 (see FIG. 1). ).

  [13] Next, the drive IC 120 is mounted on the reservoir forming substrate 30 and the compliance substrate 40 is bonded. Further, the connection wiring 130 is formed by wire bonding between the drive IC 120 and the connection portions 60 a and 90 a of the lower electrode film 60 and the lead electrode 90.

  The head 1 is manufactured through the steps as described above (see FIG. 1).

  Such heads 1 may be formed one by one by the above-described manufacturing method, or may be obtained by forming a large number of wafers at the same time and then dividing them. Also good.

In the present embodiment, the case where the communication portion 13 is formed after the third through hole 113 is formed has been described. However, the present invention is not limited to such a case. For example, the third portion is formed after the communication portion 13 is formed. The through hole 113 may be formed. That is, the elastic film (thin film) 50 may remain when the communication portion 13 is formed.

  In such a case, when the substrate manufacturing method of the present invention is applied, the space 37 is filled with the resin 400, so that the cooling medium gas can be prevented from being directly blown onto the elastic film 50, and the structure can be prevented. Since damage to the elastic film 50 exposed from the body 36 can be prevented or suppressed, it is possible to reliably prevent the elastic film 50 from being pierced (penetrated) by the cooling medium gas.

  Furthermore, in this embodiment, the structure includes a drive element structure including a piezoelectric element (drive element) as an example. However, the structure is not limited to such a case. , A terminal, an insulator, an optical element, or the like.

  Further, the substrate manufacturing method of the present invention can be applied to the manufacturing of a substrate provided in the ink jet recording head 1 as in the present embodiment, and for example, to a substrate manufacturing method provided in a vibrator, a sensor, a gyro, and the like. be able to.

  While the substrate processing method of the present invention has been described based on the illustrated embodiment by taking the method of manufacturing an inkjet discharge head as an example, the present invention is not limited to these.

  For example, the substrate manufacturing method of the present invention can be applied when a substrate is manufactured by etching a plate-like base material by a dry etching method, and, for example, by a chemical vapor deposition method (CVD method). The present invention can be applied when a substrate is manufactured by forming a film on a plate-like base material. Thereby, since the base material can be cooled uniformly, the growth speed of the film formed on the base material becomes constant, and the obtained film can be made to have a uniform thickness.

  In addition, the substrate processing method according to the present invention is not limited to a method in which one of the bonded substrates is processed and then peeled off, and may be used for manufacturing an electronic device in a bonded state. In addition, an electronic device manufactured by applying the substrate processing method according to the present invention is not limited to an ink jet printer.

  Further, in the substrate manufacturing method and the droplet discharge head manufacturing method of the present invention, one or two or more optional steps may be added.

It is an exploded perspective view showing an ink jet recording head. 2A and 2B are a plan view and a cross-sectional view illustrating an ink jet recording head. It is the schematic which shows an inkjet printer. It is a figure for demonstrating an example of the processing method of the board | substrate which concerns on this invention. It is a figure for demonstrating an example of the processing method of the board | substrate which concerns on this invention. It is a figure for demonstrating an example of the processing method of the board | substrate which concerns on this invention. It is a figure for demonstrating an example of the processing method of the board | substrate which concerns on this invention. It is a figure for demonstrating an example of the processing method of the board | substrate which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Inkjet recording head 10 ... Channel formation board 11 ... Side wall 12 ... Ink chamber 13 ... Communication part 14 ... Ink supply path 320 ... Nozzle plate 321 ... Nozzle hole 30 ... Reservoir formation board 31 …… Reservoir portion 32 …… Piezoelectric element holding portion 35 …… Adhesive layer 35a …… Joint agent 36 …… Structure 37 …… Space 40 …… Compliance substrate 41 …… Sealing film 42 …… Fixing plate 43 …… Opening 50 …… Elastic film 51 …… Oxide film 52 …… Silicon dioxide film 55 …… Insulator film 56 …… Resist layer 60 …… Lower electrode film 60a, 90a …… Connection part 70 …… Piezoelectric layer 70 ′ …… First metal layer 80 …… Upper electrode film 80 ′ …… Second metal layer 90 …… Lead electrode 91 …… Adhesion layer 92 …… Metal layer 100 …… Reservoir 110 …… Through portion 111… ... 1st Through hole 112 ...... Second through hole 113 ... Third through hole 120 ... Drive IC 130 ... Connection wiring 300 ... Piezoelectric element 2 ... Inkjet printer 22 ... Device body 221 ... Tray 222 ... ... Discharge outlet 23 ... Head unit 231 ... Ink cartridge 232 ... Carriage 24 ... Printing device 241 ... Carriage motor 242 ... Reciprocating mechanism 243 ... Carriage guide shaft 244 ... Timing belt 25 ... Feed Device 251... Feeding motor 252... Feeding roller 252 a... Driven roller 252 b ....... Driving roller 26... Control unit 27.

Claims (10)

A method of processing the other surface side of a substrate provided with a plurality of structures on one surface side,
A first step of applying an adhesive to one side of the substrate;
A second step of sequentially applying a positive pressure and a negative pressure to the adhesive;
A third step of disposing a protective substrate on the adhesive;
A fourth step of processing the other surface side of the substrate;
A fifth step of peeling the protective substrate from the substrate.   The substrate processing method according to claim 1, wherein, in the second step, a negative pressure is applied after a positive pressure is applied to the adhesive.   3. The substrate processing method according to claim 1, wherein in the second step, a positive pressure and a negative pressure are alternately applied to the adhesive twice or more each time.   The positive pressure in the second step is performed by adding water vapor, vapor of the solvent of the adhesive, and / or inert gas into the sealed container. A method for processing a substrate according to claim 1.   5. The substrate processing method according to claim 1, wherein when applying the negative pressure in the second step, water vapor or vapor of an adhesive solvent is added to the atmosphere.   6. The substrate processing method according to claim 1, wherein after the second step, prior to the third step, the adhesive is irradiated with ultrasonic waves. 6.   The ultrasonic irradiation of the second step and the adhesive is repeatedly performed after the first step until the adhesive has a required thickness, and then the third step is performed. 6. The substrate processing method according to any one of 1 to 5.   The substrate processing method according to claim 1, wherein the adhesive is degassed prior to the first step.   The substrate processing method according to claim 1, wherein the adhesive contains a photosensitive component. An electronic device comprising a substrate processed by the substrate processing method according to claim 1.

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