JP2007098680A - Method for processing silicon wafer and method for manufacturing liquid jet head - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for processing a silicon wafer capable of improving yield by effectively preventing leakage of an adhesive, and a method for manufacturing a liquid jet head. <P>SOLUTION: In this method of processing a silicon wafer, a sealing sheet 140 is bonded to one face of a silicon wafer 130 by using an adhesive layer 200 in a condition that a protection sheet 150 is interposed therebetween, and then an etching process is applied to the other face of the silicon wafer. When the sealing sheet is bonded to the one face of the silicon wafer, the thickness of the adhesive layer before the bonding of the sealing sheet to the silicon wafer is made to be not less than that of the protection sheet, and then pressurizing of the adhesive layer between the silicon wafer and the sealing sheet is stopped in a condition that the thickness of the adhesive layer is not less than that of the protection sheet. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a silicon wafer processing method for etching a silicon wafer and a liquid ejecting head manufacturing method for ejecting a liquid, and in particular, an ink jet recording head manufactured using a silicon wafer and ejecting ink droplets as a liquid. It relates to the manufacturing method.

  Conventionally, for example, a liquid ejecting head that discharges liquid droplets from a nozzle opening by applying pressure to a liquid in a pressure generating chamber by a piezoelectric element or the like is known. An ink jet recording head that discharges the ink may be used.

  Here, as the ink jet recording head, a flow path forming substrate in which a pressure generating chamber communicating with a nozzle opening is formed, a piezoelectric element provided on the flow path forming substrate via a vibration plate, and a flow path forming 2. Description of the Related Art A substrate having a protective substrate having a piezoelectric element holding portion that is bonded onto a substrate and holds a piezoelectric element is known.

  In addition, such an ink jet recording head is formed of a silicon wafer, and after a diaphragm and a piezoelectric element are formed on a flow path forming substrate wafer, a piezoelectric element holding unit that holds the piezoelectric element made of a silicon wafer from above. The protective substrate wafer having the above structure is bonded, and then the sealing sheet is adhered to the peripheral portion of the protective substrate wafer with an adhesive, and in this state, the flow path forming substrate wafer is wet etched with an etching solution such as KOH. Is manufactured by forming a pressure generating chamber or the like (see, for example, Patent Document 1).

  In such an ink jet recording head manufacturing method, when the pressure generating chamber is formed, the surface of the protective substrate wafer is completely sealed with a sealing sheet. It can be surely prevented.

  However, in the above-described conventional inkjet recording head manufacturing method, when the sealing sheet is bonded to the protective substrate wafer, for example, when the positive pressure is applied from the sealing sheet toward the protective substrate wafer. In some cases, the adhesive between the sealing sheet and the protective substrate wafer flows out from the peripheral portion of the protective substrate wafer toward the central portion due to capillary action. In particular, when the distance between the sealing sheet and the protective substrate wafer is very narrow, the adhesive layer flows out significantly. Then, if the adhesive flows out to the area where the product is to be produced, there is a problem that the product is defective and the yield is lowered.

  Such a problem does not occur in the manufacture of the above-described liquid jet head such as an ink jet recording head, but silicon that seals one surface of a silicon wafer and etches the other surface of the silicon substrate in that state. It also exists in wafer processing as well.

JP 2005-153242 A

  In view of the circumstances described above, it is an object of the present invention to provide a silicon wafer processing method and a liquid jet head manufacturing method that can effectively prevent the adhesive from flowing out and improve the yield.

According to a first aspect of the present invention for solving the above-mentioned problem, a sealing sheet is adhered by an adhesive layer in a state where a protective sheet is interposed on one surface of a silicon wafer, and then the other surface of the silicon wafer. A method of processing a silicon wafer that etches the adhesive layer before bonding the silicon wafer and the sealing sheet when the sealing sheet is bonded onto one surface of the silicon wafer. The thickness of the adhesive layer between the silicon wafer and the sealing sheet in a state where the thickness is equal to or greater than the thickness of the protective sheet and the thickness of the adhesive layer is equal to or greater than the thickness of the protective sheet. The silicon wafer processing method is characterized in that the pressing is stopped.
In the first aspect, the thickness of the adhesive layer is set so that the thickness of the adhesive layer before bonding the silicon wafer and the sealing sheet is equal to or greater than the thickness of the protective sheet, By stopping in a state equal to or greater than the thickness of the protective sheet, it is possible to effectively prevent the adhesive from flowing out between the silicon wafer and the sealing sheet. Therefore, the one surface of the silicon wafer can be kept in high quality, and the yield can be improved.

According to a second aspect of the present invention, in the first aspect, the thickness of the adhesive layer before being bonded to the silicon wafer and the sealing sheet is larger than the thickness of the protective sheet. A method for processing a wafer.
In the second aspect, by setting the thickness of the adhesive layer before bonding the protective substrate wafer and the sealing sheet to be larger than the thickness of the protective sheet, the gap between the protective substrate wafer and the sealing sheet is set. It is possible to more reliably prevent the adhesive from flowing out.

According to a third aspect of the present invention, in the first or second aspect, after the sealing sheet is disposed on the surface of the silicon wafer, the sealing sheet is placed on the silicon wafer by a plate member from the sealing sheet. The method of processing a silicon wafer is characterized by pressing to the side.
In the third aspect, the sealing sheet can be pressed substantially uniformly by pressing the sealing sheet using the plate member, and the thickness of the adhesive layer after pressing is equal to or greater than the thickness of the protective sheet. Can be.

According to a fourth aspect of the present invention, there is provided the silicon wafer processing method according to any one of the first to third aspects, wherein the sealing sheet is made of polyparaferene telestalamide (PPTA).
In the fourth aspect, since the sealing sheet made of PPTA having a linear expansion coefficient substantially equal to that of the silicon wafer is used, deformation (warping) of the silicon wafer due to heat when etching the silicon wafer is effectively prevented. can do.

In the fifth aspect of the present invention, a pressure generating chamber communicating with a nozzle opening for ejecting liquid is formed, and a flow path forming substrate having pressure generating means for generating pressure in the pressure generating chamber is integrally formed. A bonding substrate wafer that is a silicon wafer in which a bonding substrate provided corresponding to the flow path forming substrate is integrally formed on a flow path forming substrate wafer that is a silicon wafer; The thickness of the adhesive layer before bonding the bonding substrate wafer and the sealing sheet when the sealing sheet is bonded by the adhesive layer in a state where the protective sheet is interposed on the surface of the bonding wafer Of the adhesive layer between the bonding substrate wafer and the sealing sheet in a state where the thickness of the adhesive layer is equal to or greater than the thickness of the protective sheet. Stop pressing, In this state, the pressure generating chamber is formed by bonding the bonding substrate wafer and the sealing sheet, and then etching the flow path forming substrate wafer. It is in the manufacturing method.
In the fifth aspect, the thickness of the adhesive layer is set to the thickness of the adhesive layer while setting the thickness of the adhesive layer before bonding the bonded substrate wafer and the sealing sheet to be equal to or greater than the thickness of the protective sheet. By stopping at a thickness equal to or greater than the thickness of the protective sheet, it is possible to effectively prevent the adhesive from flowing out between the bonding substrate wafer and the sealing sheet. Therefore, the surface of the bonding substrate wafer can be maintained at high quality, and the yield can be improved.

Hereinafter, the present invention will be described in detail based on an embodiment.
(Embodiment 1)
FIG. 1 is an exploded perspective view showing an ink jet recording head according to Embodiment 1 of the present invention, and FIG. 2 is a plan view and a cross-sectional view of FIG. As shown in the drawing, the flow path forming substrate 10 is made of a silicon single crystal substrate having a plane orientation (110) in this embodiment, and one surface thereof is made of silicon dioxide previously formed by thermal oxidation. An elastic film 50 of 5 to 2 μm is formed. A plurality of pressure generating chambers 12 are arranged in parallel in the width direction of the flow path forming substrate 10.

  In addition, a communication portion 13 is formed in a region outside the longitudinal direction of the pressure generation chamber 12 of the flow path forming substrate 10, and the communication portion 13 and each pressure generation chamber 12 are provided for each pressure generation chamber 12. Communication is made via a supply path 14. The communication part 13 constitutes a part of a reservoir that communicates with a reservoir part of a protective substrate, which will be described later, and serves as a common ink chamber for the pressure generating chambers 12. The ink supply path 14 is formed with a narrower width than the pressure generation chamber 12, and maintains a constant flow path resistance of ink flowing into the pressure generation chamber 12 from the communication portion 13.

  As the thickness of the flow path forming substrate 10 on which such a pressure generation chamber 12 and the like are formed, it is preferable to select an optimum thickness in accordance with the density at which the pressure generation chamber 12 is disposed. For example, when the pressure generating chambers 12 are arranged at about 180 (180 dpi) per inch, the thickness of the flow path forming substrate 10 is preferably about 180 to 280 μm, more preferably about 220 μm. is there. For example, when the pressure generating chambers 12 are arranged at a relatively high density of about 360 dpi, the thickness of the flow path forming substrate 10 is preferably 100 μm or less. This is because the arrangement density can be increased while maintaining the rigidity of the partition wall 11 between the adjacent pressure generation chambers 12. In this embodiment, since the arrangement density of the pressure generating chambers 12 is about 360 dpi, the thickness of the flow path forming substrate 10 is about 70 μm.

  As shown in FIG. 3, a plurality of such flow path forming substrates 10 are integrally formed on a flow path forming substrate wafer 100, which is a silicon wafer. After the pressure generating chamber 12 and the like are formed on the substrate wafer 100, the flow path forming substrate wafer 100 is divided.

In addition, on the opening surface side of the flow path forming substrate 10, the ink supply path 14 of each pressure generating chamber 12 is connected to the ink generating path 14 through the mask film 51 which is an insulating film used as a mask when forming the pressure generating chamber 12. A nozzle plate 20 having a nozzle opening 21 communicating with the vicinity of the opposite end is fixed through an adhesive, a heat-welded film, or the like. The nozzle plate 20 has a thickness of, for example, 0.01 to 1 mm, a linear expansion coefficient of 300 ° C. or less, for example, 2.5 to 4.5 [× 10 ⁻⁶ / ° C.], glass ceramics, silicon It consists of a single crystal substrate or non-rust steel.

  On the other hand, pressure generating means is provided on the side opposite to the opening surface of the flow path forming substrate 10. Specifically, an elastic film 50 having a thickness of, for example, about 1.0 μm is formed, and an insulator film 55 having a thickness of, for example, about 0.4 μm is formed on the elastic film 50. 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 The upper electrode film 80 having a thickness of 0.05 μm is laminated by a process described later to constitute the piezoelectric element 300. Here, 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 general, one electrode of the piezoelectric element 300 is used as a common electrode, and the other electrode and the piezoelectric layer 70 are patterned for each pressure generating chamber 12. In addition, here, a portion that is configured by any one of the patterned electrodes 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. In this embodiment, the lower electrode film 60 is a common electrode of the piezoelectric element 300, and the upper electrode film 80 is an individual electrode of the piezoelectric element 300. However, there is no problem even if this is reversed for the convenience of the drive circuit and wiring. In either case, a piezoelectric active part is formed for each pressure generating chamber.

  Further, here, the piezoelectric element 300 and the vibration plate that is displaced by driving the piezoelectric element 300 are collectively referred to as a piezoelectric actuator. In the present embodiment, the elastic film 50, the insulator film 55, and the lower electrode film 60 function as a vibration plate. However, the present invention is not limited to this, and the lower electrode film 60 is not provided without providing the elastic film 50 and the insulator film 55. Only may act as a diaphragm.

  Note that a lead electrode 90 made of, for example, gold (Au) or the like is connected to the upper electrode film 80 of each piezoelectric element 300, and a voltage is selectively applied to each piezoelectric element 300 via the lead electrode 90. Is applied.

  Further, on the surface of the flow path forming substrate 10 on the piezoelectric element 300 side, for example, in this embodiment, a piezoelectric substrate that can secure a space that does not hinder its movement in a region facing the piezoelectric element 300 as a bonding substrate. A protective substrate 30 having an element holding portion 31 is bonded. Since the piezoelectric element 300 is formed in the piezoelectric element holding part 31, it is protected in a state hardly affected by the external environment. The piezoelectric element holding part 31 may be sealed or may not be sealed.

  Further, the protective substrate 30 is provided with a reservoir portion 32 in a region corresponding to the communication portion 13 of the flow path forming substrate 10. In the present embodiment, the reservoir portion 32 is provided along the direction in which the pressure generating chambers 12 are arranged so as to penetrate the protective substrate 30 in the thickness direction. A reservoir 110 that is in communication with the communication unit 13 and serves as a common ink chamber for the pressure generation chambers 12 is configured. Further, a through hole 33 that penetrates the protective substrate 30 in the thickness direction is provided in a region between the piezoelectric element holding portion 31 and the reservoir portion 32 of the protective substrate 30. The lead electrode 90 drawn out from each piezoelectric element 300 extends to the through hole 33 and is connected to a drive IC or the like for driving the piezoelectric element 300 by wire bonding or the like (not shown). Further, a wiring pattern (not shown) or the like is provided on the surface of the protective substrate 30, and a driving IC is mounted thereon.

  In addition, examples of the material of the protective substrate 30 include glass, ceramic material, metal, resin, and the like, but it is more preferable that the material is substantially the same as the coefficient of thermal expansion of the flow path forming substrate 10. In this embodiment, the silicon single crystal substrate made of the same material as the flow path forming substrate 10 is used.

  A compliance substrate 40 including a sealing film 41 and a fixing plate 42 is bonded onto the protective substrate 30. The sealing film 41 is made of a material having low rigidity and flexibility (for example, a polyphenylene sulfide (PPS) film having a thickness of 6 μm), and one surface of the reservoir portion 32 is sealed by the sealing film 41. Yes. The fixing plate 42 is made of a hard material such as metal (for example, stainless steel (SUS) having a thickness of 30 μm). Since the region of the fixing plate 42 facing the reservoir 110 is an opening 43 that is completely removed in the thickness direction, one surface of the reservoir 110 is sealed only by the flexible sealing film 41. Has been.

  Note that such an ink jet recording head takes in ink from an external ink supply means (not shown), fills the interior from the reservoir 110 to the nozzle opening 21, and then externally in accordance with a recording signal from a drive circuit (not shown). By applying a voltage between each of the lower electrode film 60 and the upper electrode film 80 corresponding to the pressure generation chamber 12 via the wiring, the elastic film 50, the lower electrode film 60, and the piezoelectric layer 70 are bent and deformed. The pressure in each pressure generating chamber 12 is increased, and ink droplets are ejected from the nozzle openings 21.

  Hereinafter, a method for manufacturing the ink jet recording head according to the present embodiment will be described. 4 to 6 and 8 are diagrams for explaining the manufacturing process of the ink jet recording head, and are sectional views in the longitudinal direction of the pressure generating chamber. FIG. 7 is an enlarged view of a main part for explaining the manufacturing process of the ink jet recording head.

  First, as shown in FIG. 4A, a channel forming substrate wafer 100 which is a silicon wafer is thermally oxidized in a diffusion furnace at about 1100 ° C., and a silicon dioxide film 52 constituting an elastic film 50 is formed on the surface thereof. To do. In the present embodiment, as the flow path forming substrate wafer 100, a silicon wafer having a relatively thick and high rigidity of about 625 μm is used.

Next, as shown in FIG. 4B, a zirconium (Zr) layer is formed on the elastic film 50 (silicon dioxide film 52), and then thermally oxidized in, for example, a diffusion furnace at 500 to 1200 ° C. to form zirconium oxide ( An insulator film 55 made of ZrO ₂ ) is formed. Next, as shown in FIG. 4C, for example, after the lower electrode film 60 is formed by laminating platinum and iridium on the insulator film 55, the lower electrode film 60 is patterned into a predetermined shape.

  Next, as shown in FIG. 4D, for example, a piezoelectric layer 70 made of lead zirconate titanate (PZT) or the like and an upper electrode film 80 made of iridium (Ir), for example, are connected to the flow path forming substrate. And formed on the entire surface of the wafer 100. Next, as shown in FIG. 5A, the piezoelectric layer 70 and the upper electrode film 80 are patterned to form the piezoelectric elements 300 in the regions to be the pressure generation chambers 12. Next, as shown in FIG. 5B, the lead electrode 90 is formed over the entire surface of the flow path forming substrate 10 and patterned for each piezoelectric element 300.

  Next, as shown in FIG. 5C, a plurality of protective substrates 30 provided as bonding substrate wafers on the piezoelectric element 300 side of the flow path forming substrate wafer 100 corresponding to each flow path forming substrate 10. A protective substrate wafer 130, which is a silicon wafer, is bonded. Since the protective substrate wafer 130 has a thickness of, for example, about 400 μm, the rigidity of the flow path forming substrate wafer 100 is remarkably improved by bonding the protective substrate wafer 130.

  Next, as shown in FIG. 6A, after the flow path forming substrate wafer 100 is polished to a certain thickness, it is further subjected to wet etching with hydrofluoric acid, for example, spin etching, for flow path forming substrate use. The wafer 100 is set to a predetermined thickness. In the present embodiment, the flow path forming substrate wafer 100 is etched to have a thickness of about 70 μm.

  Next, as shown in FIG. 6B, a mask film 51 made of, for example, silicon nitride (SiN) is newly formed on the flow path forming substrate wafer 100 and patterned into a predetermined shape. Then, as shown in FIG. 6C, the surface of the protective substrate wafer 130 is adhered to the protective substrate wafer 130 by adhering a sealing sheet 140 made of polyparaphyllene telestalamide (PPTA) with an adhesive. Is covered with this sealing sheet 140 and sealed. That is, the reservoir portion 32 and the like formed through the protective substrate wafer 130 in the thickness direction are completely sealed by the sealing sheet 140.

  At this time, the sealing sheet 140 is adhered to the peripheral portion of the surface of the protective substrate wafer 130 and is not adhered to the region to be the protective substrate 30. In the present embodiment, the sealing sheet 140 is bonded in a state where the protective sheet 150 is interposed between the sealing sheet 140 and the protective substrate wafer 130.

  For example, in this embodiment, the adhesion between the protective substrate wafer 130 and the sealing sheet 140 is along the product portion of the protective substrate wafer 130, that is, along the peripheral edge of the region where each protective substrate 30 is formed. Then, an adhesive is applied to form an adhesive layer 200 having a predetermined thickness, and the sealing sheet 140 is brought into contact with the adhesive layer 200. Next, from above the sealing sheet 140, a flat plate such as a SUS plate is used. This is performed by pressing the entire surface of the sealing sheet 140 substantially uniformly by the plate member 160 and drying it.

In this embodiment, the thickness of the adhesive layer 200 before bonding the protective substrate wafer 130 and the sealing sheet 140 is set to be equal to or greater than the thickness of the protective sheet 150. That is, the adhesive layer is such that the relationship between the thickness [d ₁ ] of the adhesive layer 200 before bonding and the thickness [d ₂ ] of the protective sheet 150 satisfies the condition [d ₁ ] ≧ [d ₂ ]. 200 was formed. In particular, as shown in FIG. 7A, the thickness [d ₁ ] of the adhesive layer 200 before bonding is larger than the thickness [d ₂ ] of the protective sheet 150, that is, [d ₁ ]> [d ₂ It is preferable to form the adhesive layer 200 so as to satisfy the condition of Thereby, since the sealing sheet 140 and the adhesive bond layer 200 are in reliable contact with each other, it is possible to more reliably prevent poor adhesion between them.

  Further, when the adhesive layer 200 is pressed between the protective substrate wafer 130 and the sealing sheet 140, the thickness of the adhesive layer 200 after bonding (pressing) is equal to or greater than the thickness of the protective sheet 150. Thus, the pressing of the adhesive layer 200 is stopped. In this embodiment, as shown in FIGS. 7B and 7C, the plate member 160 is used, and the adhesive layer 200 is pressed from above the sealing sheet 140 by the plate member 160. The thickness of the adhesive layer 200 is substantially equal to the thickness of the protective sheet 150. That is, at least in an area corresponding to the peripheral edge of the protective substrate wafer 130 (adhesion area), the thickness of the adhesive layer 200 after adhesion is not smaller than the thickness of the protection sheet 150, that is, after adhesion. The pressing operation can be stopped while the thickness of the adhesive layer 200 is substantially equal to the thickness of the protective sheet 150.

Further, as in the present embodiment, the adhesive layer 200 before bonding is formed under the thickness condition of [d ₁ ]> [d ₂ ] while the pressing operation of the adhesive layer 200 is performed after bonding. Since the thickness of the protective sheet 150 is substantially the same as the thickness of the protective sheet 150, it is possible to effectively prevent the adhesive layer 200 from flowing out to the central portion (product portion) side of the protective substrate wafer 130. Moreover, the protective substrate wafer 130 and the sealing sheet 140 can be reliably bonded by the adhesive layer 200.

  Moreover, in this embodiment, since the plate member 160 that is a flat plate is used for pressing the sealing sheet 140, it is possible to press the adhesive layer 200 so that the adhesive layer 200 has a predetermined thickness in the surface direction. Further, by using the plate member 160 in the adhesion between the protective substrate wafer 130 and the sealing sheet 140, it is possible to effectively prevent the adhesive displacement between the protective substrate wafer 130 and the sealing sheet 140. There is also.

  As described above, in the manufacturing method of the present embodiment, when the sealing sheet 140 is adhered by the adhesive layer 200 with the protective sheet 150 interposed on the surface of the protective substrate wafer 130, the protective substrate is used. By making the thickness of the adhesive layer 200 before bonding the wafer 130 and the sealing sheet 140 larger than the thickness of the protective sheet 150, it is possible to prevent poor adhesion between the protective substrate wafer 130 and the sealing sheet 140. , The pressing of the adhesive layer 200 between the sealing sheet 140 and the protective substrate wafer 130 is stopped when the thickness of the adhesive layer 200 is equal to or greater than the thickness of the protective sheet 150, so that the product portion of the adhesive layer The outflow to the side can be effectively prevented.

  Here, in the above-described embodiment, the case where the thickness of the adhesive layer 200 before bonding is made larger than the thickness of the protective sheet 150 has been described, but the present invention is not limited to this, and bonding before bonding is of course possible. The thickness of the agent layer may be equivalent to the thickness of the protective sheet. In this case, the sealing sheet 140 hangs down to the end side of the protective substrate wafer 130 in the vicinity of the peripheral edge portion of the protective substrate wafer 130 due to its own weight (weight). The substrate wafer 130 and the sealing sheet 140 are favorably bonded via the adhesive layer 200. That is, even in this case, since the sealing sheet 140 and the adhesive layer 200 are reliably in contact with each other, poor adhesion between the protective substrate wafer 130 and the sealing sheet 140 can be reliably prevented.

  In this embodiment, since the protective sheet 150 is interposed between the protective substrate wafer 130 and the sealing sheet 140, when the sealing sheet 140 is pressed through the plate member 160, the protective substrate 30. Scratches and the like can be reliably prevented from forming on the upper surface of the substrate. That is, the upper surface of the protective substrate 30 can be kept high.

  Note that the protective sheet 150 interposed between the protective substrate wafer 130 and the sealing sheet 140 is not bonded to the protective substrate wafer 130, and is basically between the protective substrate wafer 130 and the sealing sheet 140. This is for securing a predetermined space. That is, the protective sheet 150 has an outer shape smaller than that of the sealing sheet 140, and is disposed corresponding to the sealing space in the sealing sheet 140, in particular, the region where each protective substrate 30 serving as a product portion is provided. It is. The protective sheet 150 also serves to prevent peeling or damage of a wiring pattern (not shown) provided in advance on the surface of the protective substrate wafer 130.

  Such a protective sheet 150 may be interposed between the protective substrate wafer 130 and the sealing sheet 140 in a non-adhesive manner. For example, in this embodiment, the protective sheet 150 is used as the sealing sheet 140. In this state, the sealing sheet 140 is adhered to the peripheral portion of the protective substrate wafer 130 so as to be interposed between the protective substrate wafer 130 and the sealing sheet 140. I made it.

  Examples of the material of the protective sheet 150 include polytetrafluoroethylene (PTFE), polyethylene terephthalate (PET), polyphenylene sulfide (PPS), and the like, which adversely affect the surface of the protective substrate wafer 130. It is preferable to use a material that does not interfere with the surface of the protective substrate wafer 130. Examples of such a material include a fluororesin, and polytetrafluoroethylene (PTFE) is used in this embodiment.

  In this embodiment, the adhesive layer 200 is formed by applying an adhesive to the peripheral edge of the protective substrate wafer 130. However, the present invention is not limited to this, and the sealing sheet 140 and the protective substrate wafer 130 are bonded to each other. The adhesive for bonding may be applied to either the sealing sheet 140 or the protective substrate wafer 130. The method for applying the adhesive is not particularly limited, and when applying to the sealing sheet 140, for example, a film transfer method or the like may be used. Moreover, when apply | coating to the wafer 130 for protective substrates, what is necessary is just to make it apply | coat directly with a dispenser etc., for example.

  Then, after the sealing sheet 140 is bonded in this way, the flow path forming substrate wafer 100 is anisotropically etched through the mask film 51 to form a flow path as shown in FIG. A pressure generation chamber 12, a communication portion 13, an ink supply path 14, and the like are formed in the substrate wafer 100. At this time, the surface of the protective substrate wafer 130 is covered with the sealing sheet 140 and the surface of the flow path forming substrate wafer 100 on the piezoelectric element 300 side is completely sealed. Alternatively, the piezoelectric element 300 can be reliably prevented from being destroyed by the etching solution.

  Further, since the sealing sheet 140 of this embodiment is made of PPTA and has substantially the same thermal expansion coefficient as the flow path forming substrate wafer 100 and the protective substrate wafer 130 which are silicon wafers, the flow path forming substrate wafer The wafer 100 and 130 are not warped or deformed by the heat generated during the etching of 100 or the like. Therefore, the pressure generating chamber 12 and the like can be formed with high accuracy by etching, and an ink jet recording head that can obtain good ejection characteristics can be realized.

  Specifically, when the flow path forming substrate wafer 100 is etched, the wafers 100 and 130 and the sealing sheet 140 are heated to about 80 ° C., and thus expand due to this heat. For this reason, if the linear expansion coefficients of the flow path forming substrate wafer 100 and the protective substrate wafer 130 and the sealing sheet 140 are greatly different, the respective wafers 100 and 130 may be deformed and cracked due to the difference in expansion coefficient. There is. Moreover, for example, the adhesive that adheres the sealing sheet 140 may be temporarily softened by this heat. In this case, the sealing sheet 140 is fixed to the protective substrate wafer 130 in a state of being expanded by heat, and when the wafers 100 and 130 and the sealing sheet 140 are cooled and contracted after completion of etching, The wafers 100 and 130 may be deformed and cracked.

However, in this embodiment, the sealing sheet 140 is made of PPTA, and the linear expansion coefficient (2.0 × 10 ⁻⁶ / ° C.) of the sealing sheet 140 is the linear expansion coefficient (3.0 × 10 10) of the silicon wafer. ⁻⁶ / ° C.), the wafers 100 and 130 and the sealing sheet 140 expand or contract by approximately the same amount by heating or cooling, and the wafers 100 and 130 are deformed such as warpage. It does not occur. However, as a matter of course, the material of the sealing sheet 140 is not limited to the PPTA described above.

  Next, as shown in FIG. 8B, the sealing sheet 140 is applied to a region that is not bonded to the protective substrate wafer 130, for example, a space portion formed by the protective sheet 150 in this embodiment. The sealing sheet 140 and the protective sheet 150 are removed. Thus, if only the sealing sheet 140 is cut and the sealing sheet 140 and the like are removed, the time required for removing the sealing sheet 140 can be remarkably shortened, and the manufacturing efficiency is greatly improved. be able to.

  After that, as shown in FIG. 8C, unnecessary portions of the outer peripheral edge portions of the flow path forming substrate wafer 100 and the protective substrate wafer 130, that is, the portion where the sealing sheet 140 is bonded, For example, it is removed by cutting by dicing or the like. Then, the nozzle plate 20 having the nozzle openings 21 formed on the surface of the flow path forming substrate wafer 100 opposite to the protective substrate wafer 130 is bonded, and the compliance substrate 40 is bonded to the protective substrate wafer 130. The ink jet recording head of the present embodiment is obtained by dividing the flow path forming substrate wafer 100 and the like into the flow path forming substrate 10 and the like having a single chip size as shown in FIG.

(Other embodiments)
As mentioned above, although embodiment of this invention was described, of course, this invention is not limited to these embodiment. For example, in Embodiment 1 described above, a thin film type ink jet recording head manufactured by applying a film forming and lithography method is taken as an example. However, the present invention is not limited to this example. The present invention can be applied to a thick film type ink jet recording head formed by such a method.

  Further, although the piezoelectric element is used as the pressure generating means for ejecting ink droplets from the nozzle openings, the pressure generating means is not limited to the piezoelectric element. For example, a heating element is arranged in the pressure generating chamber, and the heating element is arranged. So that droplets are ejected from the nozzle opening by bubbles generated by the heat generated by the nozzle, and so-called static electricity is generated between the diaphragm and the electrode, and the diaphragm is deformed by electrostatic force to eject the droplet from the nozzle opening. An electrostatic actuator or the like can be used.

  Furthermore, in the above-described embodiment, the present invention has been described with respect to an example of a method for manufacturing an ink jet recording head. However, the present invention is not limited to this, and the present invention is intended for a wide range of methods for manufacturing a liquid jet head. Of course, the present invention can also be applied to a manufacturing method for ejecting liquids other than ink. Other liquid ejecting heads include, for example, various recording heads used in image recording apparatuses such as printers, color material ejecting heads used in the manufacture of color filters such as liquid crystal displays, organic EL displays, and FEDs (surface emitting displays). Examples thereof include an electrode material ejection head used for electrode formation, a bioorganic matter ejection head used for biochip production, and the like.

  Further, the present invention is applied not only to the manufacture of the liquid jet head described above, but also to processing of a silicon wafer in which one side of a silicon wafer is sealed and the other side of the silicon wafer is processed by etching or the like in that state. Is possible. Even in this case, it is possible to effectively prevent the adhesive layer from flowing out from the bonded area between the silicon wafer and the sealing sheet to the product portion, and it is possible to maintain the one surface side of the silicon wafer with high quality. Therefore, the yield can be improved.

  Of course, in the present invention, the silicon wafer processing method described above is performed by forming a wiring pattern or the like on one side of the silicon wafer and etching the other side of the silicon wafer to form a recess or the like. In this case, the same effect as described above can be obtained.

2 is a schematic perspective view of a recording head according to Embodiment 1. FIG. 2A and 2B are a plan view and a cross-sectional view of the recording head according to the first embodiment. 1 is a perspective view showing a flow path forming substrate wafer according to Embodiment 1. FIG. 5 is a cross-sectional view illustrating a manufacturing process of the recording head according to Embodiment 1. FIG. 5 is a cross-sectional view illustrating a manufacturing process of the recording head according to Embodiment 1. FIG. 5 is a cross-sectional view illustrating a manufacturing process of the recording head according to Embodiment 1. FIG. 6 is an enlarged view of a main part for explaining a manufacturing process of the recording head according to Embodiment 1. FIG. 5 is a cross-sectional view illustrating a manufacturing process of the recording head according to Embodiment 1. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Flow path formation board | substrate, 11 Partition, 12 Pressure generation chamber, 13 Communication part, 14 Ink supply path, 20 Nozzle plate, 21 Nozzle opening, 30 Protection board, 50 Elastic film, 60 Lower electrode film, 70 Piezoelectric layer, 80 Upper electrode film, 100 channel forming substrate wafer, 110 reservoir, 130 protective substrate wafer, 140 sealing sheet, 150 protective sheet, 160 plate member, 200 adhesive layer, 300 piezoelectric element

Claims (5)

A silicon wafer processing method of adhering a sealing sheet with an adhesive layer in a state where a protective sheet is interposed on one side of a silicon wafer, and then etching the other side of the silicon wafer,
When adhering the sealing sheet on one surface of the silicon wafer, the thickness of the adhesive layer before adhering the silicon wafer and the sealing sheet is set to be equal to or greater than the thickness of the protective sheet. The silicon is characterized in that pressing of the adhesive layer between the silicon wafer and the sealing sheet is stopped when the thickness of the adhesive layer is equal to or greater than the thickness of the protective sheet. Wafer processing method. 2. The method for processing a silicon wafer according to claim 1, wherein a thickness of the adhesive layer before bonding the silicon wafer and the sealing sheet is made larger than a thickness of the protective sheet. 3. The silicon according to claim 1, wherein after the sealing sheet is disposed on the surface of the silicon wafer, the sealing sheet is pressed toward the silicon wafer by a plate member from above the sealing sheet. Wafer processing method. The silicon wafer processing method according to claim 1, wherein the sealing sheet is made of polyparaferene telestalamide (PPTA). A flow path forming substrate which is a silicon wafer in which a pressure generating chamber communicating with a nozzle opening for ejecting liquid is formed and a flow path forming substrate having pressure generating means for generating pressure in the pressure generating chamber is integrally formed After bonding a bonding substrate wafer, which is a silicon wafer in which a bonding substrate provided corresponding to the flow path forming substrate is integrally formed on the bonding wafer, a protective sheet is placed on the surface of the bonding substrate wafer. When adhering the sealing sheet with the adhesive layer in an interposed state, the thickness of the adhesive layer before adhering the bonding substrate wafer and the sealing sheet is equal to or greater than the thickness of the protective sheet. And stopping the pressing of the adhesive layer between the bonding substrate wafer and the sealing sheet in a state where the thickness of the adhesive layer is equal to or greater than the thickness of the protective sheet, Bonded substrate Bonding the wafer and said sealing sheet, then, the production method of the liquid ejecting head is characterized in that so as to form the pressure generating chamber by etching the passage forming wafer substrate.

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