JP2018046173A - Substrate bonding method, manufacturing method for mems device, and manufacturing method for liquid injection head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a substrate bonding method capable of suppressing cracking, chipping and the like of a silicon substrate, without causing an increase in process, and to provide a manufacturing method for an MEMS device, and a manufacturing method for a liquid injection head.SOLUTION: A substrate bonding method has an alignment step of determining relative positions of a first substrate (40) and a second substrate (41), and a bonding step of bonding the first substrate and second substrate in a state where the relative positions are determined by the alignment step. A difference between an external-diameter (D1) of the first substrate and an external-diameter (D2) of the second substrate is two times or more of the sum of an allowable tolerance (σ1) of the position of the first substrate and an allowable tolerance (σ2) of the position of the second substrate in the alignment step.SELECTED DRAWING: Figure 11

Description

  The present invention relates to a substrate bonding method for bonding a first substrate and a second substrate in a positioned state, a method for manufacturing a MEMS device, and a method for manufacturing a liquid jet head.

  A MEMS (Micro Electro Mechanical Systems) device includes a driving element such as a piezoelectric element on a silicon substrate, and is applied to various liquid ejecting apparatuses, display apparatuses, vibration sensors, and the like. For example, in a liquid ejecting apparatus, various liquids are ejected from a liquid ejecting head that is a form of a MEMS device. As this liquid ejecting apparatus, for example, there is an image recording apparatus such as an ink jet printer or an ink jet plotter, but recently, various types of manufacturing have been made by taking advantage of the ability to accurately land a very small amount of liquid on a predetermined position. It is also applied to devices. For example, a display manufacturing apparatus for manufacturing a color filter such as a liquid crystal display, an electrode forming apparatus for forming an electrode such as an organic EL (Electro Luminescence) display or FED (surface emitting display), a chip for manufacturing a biochip (biochemical element) Applied to manufacturing equipment. The recording head for the image recording apparatus ejects liquid ink, and the color material ejecting head for the display manufacturing apparatus ejects solutions of R (Red), G (Green), and B (Blue) color materials. The electrode material ejecting head for the electrode forming apparatus ejects a liquid electrode material, and the bioorganic matter ejecting head for the chip manufacturing apparatus ejects a bioorganic solution.

  Some liquid ejecting heads have a laminated structure in which a plurality of substrates are joined in a laminated state. The laminated structure is provided with a liquid channel communicating with the nozzle, a movable region for causing a pressure fluctuation in the liquid in the liquid channel and ejecting the liquid from the nozzle. For example, in the method of manufacturing an ink jet recording head disclosed in Patent Document 1, a silicon single crystal substrate (hereinafter simply referred to as a silicon wafer or a silicon substrate) is used as the substrate, and the silicon substrates are bonded to each other. Then, one of the silicon substrates is ground to a required thickness, and the flow path and the like are prepared on the silicon substrate by wet etching, and then divided into necessary chip sizes.

  By the way, the outer peripheral portion of the silicon substrate is chamfered in advance in order to prevent chipping, cracking, and the like. In this case, the thickness of the portion is thinner than the thickness of other portions. In this case, in the configuration in which the silicon substrate is ground and thinned as described above, the thickness of the outer peripheral portion of the silicon substrate is further reduced, so that cracks and chips are more likely to occur. For this reason, in the recording head disclosed in Patent Document 1, a recess is formed in the other silicon substrate so that one silicon substrate can be accommodated, and the silicon substrate is ground in a state where the one silicon substrate is accommodated in the recess. The outer peripheral portion is configured to prevent cracking and chipping.

JP 2011-178145 A

  However, since the recess is formed in the other silicon substrate as described above, the number of processing steps increases accordingly. In addition, by forming such a recess, foreign matter such as shavings is generated, and there is a problem that the yield is reduced due to the foreign matter.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a substrate bonding method and a MEMS device capable of suppressing cracking or chipping of a silicon substrate without increasing the number of steps. It is an object to provide a manufacturing method and a manufacturing method of a liquid jet head.

The substrate bonding method of the present invention has been proposed in order to achieve the above object, and an alignment step for determining a relative position between the first substrate and the second substrate;
A bonding step of bonding the first substrate and the second substrate with the relative position determined by the alignment step;
Have
The difference between the outer diameter of the first substrate and the outer diameter of the second substrate is the tolerance for the position of the first substrate and the tolerance for the position of the second substrate in the alignment step. It is characterized by being at least twice the total of

  According to the present invention, due to an error in the alignment process, one end of the first substrate in the position adjustment direction of each substrate is displaced from the specified position to the end side of the second substrate to the maximum tolerance. In addition, even when one end of the second substrate in the position adjusting direction is displaced to the maximum tolerance from the specified position toward the end of the first substrate, the end of the first substrate is It is possible to prevent the second substrate from projecting to the outer side (the side away from the center in the position adjustment direction of the second substrate). This suppresses cracking or chipping of the first substrate during processing of the first substrate, etc., without increasing the number of steps for processing the recess for accommodating the first substrate in the second substrate. It becomes possible to do. As a result, the yield of the laminated structure formed by bonding the first substrate and the second substrate is improved.

  Moreover, this invention is suitable when it has a grinding process which grinds the said 1st board | substrate after the said joining process.

  According to the above configuration, the first substrate is ground and thinned, so that cracks and chips are more likely to occur. Even in this case, the end of the first substrate is more than the end of the second substrate. Since it does not protrude outward, it becomes possible to effectively suppress cracks and chips.

Further, the present invention is a method for manufacturing a MEMS device having a laminated structure formed by bonding a first substrate and a second substrate,
It includes the above-described substrate bonding method.

  According to the present invention, since the first substrate is prevented from being cracked or chipped, the yield in manufacturing the MEMS device is improved.

The present invention also provides a liquid channel communicating with a nozzle in a laminated structure formed by bonding a first substrate and a second substrate, and a drive element for ejecting liquid in the liquid channel from the nozzle A method of manufacturing a liquid jet head having
It includes the above-described substrate bonding method.

  According to the present invention, since the first substrate is prevented from being cracked or chipped, the yield in manufacturing the liquid jet head is improved.

FIG. 6 is a perspective view illustrating a configuration of a liquid ejecting apparatus (printer). 3 is a plan view illustrating a configuration of a liquid ejecting head (recording head). FIG. It is the sectional view on the AA line in FIG. It is sectional drawing of a 1st wafer (1st board | substrate). It is sectional drawing of a 2nd wafer (2nd board | substrate). It is a perspective view explaining an alignment process. It is a figure which shows the state which bonded together the 1st wafer and the 2nd wafer. It is a figure which shows the state which ground the 1st wafer. It is a figure which shows the state which formed the pressure chamber etc. in the 1st wafer. It is a figure which shows the state which excised the excess part of the 1st wafer and the 2nd wafer. It is a schematic diagram explaining the error of alignment.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described with reference to the accompanying drawings. In the embodiments described below, various limitations are made as preferred specific examples of the present invention. However, the scope of the present invention is not limited to the following description unless otherwise specified. However, the present invention is not limited to these embodiments. In the present embodiment, a description will be given using a recording head (inkjet head) 2 which is one aspect of a MEMS device having a laminated structure. In this recording head 2, for example, a driving element that receives an electric signal from the outside and drives the movable area corresponds to the piezoelectric element 19 (see FIG. 3) of the recording head 2, and there is a space that allows driving of the movable area. This corresponds to the pressure chamber 15 (see FIG. 3) of the recording head 2. The present invention can also be applied to a configuration in which a drive element converts a pressure change in space into an electrical signal and outputs the electrical signal to the outside of the MEMS device.

  FIG. 1 is a perspective view showing the configuration of the printer 1. The printer 1 includes a recording head 2 and a carriage 4 to which an ink cartridge 3 (liquid supply source) is detachably attached. The carriage 4 is attached to the recording paper 6 (recording medium and a kind of landing target) in the paper width direction, that is, A carriage moving mechanism 7 that reciprocates in the main scanning direction, and paper that conveys the recording paper 6 in the sub-scanning direction (second direction) intersecting (orthogonal in the present embodiment) in the main scanning direction (first direction). A feed mechanism 8 and the like are provided. The printer 1 records characters, images, and the like on the recording paper 6 while sequentially transporting the recording paper 6 and reciprocating the carriage 4. It is also possible to employ a configuration in which the ink cartridge 3 is disposed not on the carriage 4 but on the main body side of the printer 1 and ink in the ink cartridge 3 is supplied to the recording head 2 side through an ink supply tube.

  FIG. 2 is a plan view of the recording head 2 in the present embodiment, and FIG. 3 is a cross-sectional view of the main part of the recording head 2 taken along line AA in FIG. The recording head 2 in this embodiment is configured by laminating a flow path forming substrate 10, a nozzle plate 11, an actuator unit 12, a sealing plate 13, and the like. The flow path forming substrate 10 is made of, for example, a silicon single crystal substrate having a surface orientation (110) on the surface (bonding surface) to which the nozzle plate 11 and the sealing plate 13 are bonded. In the flow path forming substrate 10, vacancies defining the pressure chambers 15 are formed side by side in the nozzle row direction by anisotropic etching. The pressure chamber 15 is a space formed by closing one opening of the above-described empty portion of the flow path forming substrate 10 by the nozzle plate 11 and closing the other opening of the empty portion by the diaphragm 14. . The empty space of the pressure chamber 15 in the present embodiment has a substantially parallelogram-shaped opening that is long in a direction orthogonal to the nozzle row direction.

  In a region outside the pressure chamber 15 in the longitudinal direction of the flow path forming substrate 10 (the side opposite to the side communicating with the nozzle 18), a reservoir 16 common to the pressure chambers 15 extends along the nozzle row direction. Is formed. The reservoir 16 and each pressure chamber 15 communicate with each other through an individual supply port 17 provided for each pressure chamber 15. The reservoir 16 is provided for each type of ink (for each color), and common ink is stored in the plurality of pressure chambers 15. The individual supply port 17 is formed with a narrower width than the pressure chamber 15, and imparts flow path resistance to the ink flowing from the reservoir 16 into the pressure chamber 15.

  The nozzle plate 11 is bonded to the lower surface of the flow path forming substrate 10 (the surface opposite to the vibration plate 14 side) via an adhesive, a heat welding film, or the like. The nozzle plate 11 is a plate material in which a plurality of nozzles 18 are arranged in a row at a predetermined pitch. In the present embodiment, a nozzle row (a kind of nozzle group) is configured by arranging a plurality of nozzles 18 at a predetermined pitch (for example, 360 [dpi]). Each nozzle 18 communicates with the end of the pressure chamber 15 opposite to the individual supply port 17. The nozzle plate 11 is made of, for example, glass ceramics, a silicon single crystal substrate, or stainless steel.

The actuator unit 12 in this embodiment includes a diaphragm 14, a piezoelectric element 19, and a lead electrode 20. The diaphragm 14 includes an elastic film 21 formed on the upper surface of the flow path forming substrate 10 and an insulating film 22 formed on the elastic film 21. The elastic film 21 is made of, for example, silicon dioxide (SiO ₂ ), and the insulating film 22 is made of, for example, zirconium oxide (ZrO ₂ ). A portion of the diaphragm 14 corresponding to the pressure chamber 15, that is, a portion that closes the upper opening of the pressure chamber 15 (empty portion) is displaced in a direction away from or near to the nozzle 18 due to the bending deformation of the piezoelectric element 19. Functions as a movable region (driving unit). A communication opening 23 communicating with the reservoir 16 is formed at a portion of the diaphragm 14 corresponding to the reservoir 16 of the flow path forming substrate 10.

  A piezoelectric element 19 is formed in a portion corresponding to the pressure chamber 15 in the insulating film 22 of the vibration plate 14. The piezoelectric element 19 in this embodiment is configured by laminating a lower electrode film 25 (first electrode), a piezoelectric film 26, and an upper electrode film 27 (second electrode) in this order from the diaphragm 14 side. In the present embodiment, the lower electrode film 25 and the piezoelectric film 26 are patterned for each pressure chamber 15, and the lower electrode film 25 is an individual electrode for each piezoelectric element 19. On the other hand, the upper electrode film 27 is an electrode common to each piezoelectric element 19. That is, the upper electrode film 27 is continuously formed across the pressure chambers 15 along the pressure chamber juxtaposition direction. In the stacking direction, the portion where the upper electrode film 27, the piezoelectric film 26, and the lower electrode film 25 overlap is a piezoelectric active portion in which piezoelectric distortion occurs due to voltage application to both electrode layers. That is, the upper electrode film 27 is a common electrode of the piezoelectric element 19, and the lower electrode film 25 is an individual electrode of the piezoelectric element 19. It is also possible to adopt a configuration in which the lower electrode film is a common electrode and the upper electrode film is an individual electrode.

  On the upper electrode film 27, a lead electrode 20 made of gold (Au) is formed via an adhesion layer (not shown) such as NiCr. The lead electrode 20 is patterned corresponding to each lower electrode film 25 that is an individual electrode, and is electrically connected to the lower electrode film 25. A drive voltage (drive pulse) is selectively applied to each piezoelectric element 19 through the lead electrode 20.

  The piezoelectric film 26 in the present embodiment is formed on the vibration plate 14 so as to cover the lower electrode film 25. As the piezoelectric film 26, a ferroelectric piezoelectric material such as lead (Pb), titanium (Ti) and zirconium (Zr), for example, lead zirconate titanate (PZT), niobium oxide, What added metal oxides, such as nickel oxide or magnesium oxide, etc. can be used.

  A sealing plate 13 having an accommodation space 29 that can accommodate the piezoelectric element 19 is joined to the upper surface of the actuator unit 12 opposite to the lower surface that is the joining surface with the flow path forming substrate 10. The sealing plate 13 is a hollow box-shaped member having an accommodation cavity 29 opened on the lower surface side which is a joint surface with the flow path forming substrate 10 on which the actuator unit 12 is laminated. In the present embodiment, Similar to the flow path forming substrate 10, it is made of a silicon single crystal substrate. The accommodation space 29 is a recess formed halfway in the height direction of the sealing plate 13 from the lower surface side to the upper surface side of the sealing plate 13. The dimension (inner method) of the accommodation empty portion 29 in the nozzle row direction is set to a size that can accommodate all the piezoelectric elements 19 in the same row. In addition, the dimension of the accommodation empty portion 29 in the direction perpendicular to the nozzle row is set to a size that can accommodate the piezoelectric active of the piezoelectric element 19. Further, as shown in FIG. 2, the sealing plate 13 is located at a position outside the accommodating void portion 29 in the direction orthogonal to the nozzle row, and the communication opening 23 and the flow path formation of the diaphragm 14 are formed. In a region corresponding to the reservoir 16 of the substrate 10, a liquid chamber cavity 30 is provided. The liquid chamber hollow portion 30 is provided along the direction in which the pressure chambers 15 are arranged so as to penetrate the sealing plate 13 in the thickness direction, and communicate with the communication opening 23 and the reservoir 16 in series as described above. To do. The flow path forming substrate 10 and the sealing plate 13 bonded to the flow path forming substrate 10 are configured by dividing a laminated structure composed of a first wafer 40 and a second wafer 41 described later. Therefore, the laminated body of the flow path forming substrate 10 and the sealing plate 13 is a kind of laminated structure in the present invention.

  A compliance substrate 31 composed of a sealing film 32 and a fixing plate 33 is bonded onto the sealing plate 13. The sealing film 32 is made of a material having low rigidity and flexibility (for example, a polyphenylene sulfide film, a thin stainless film, etc.), and one surface of the liquid chamber cavity 30 is sealed by the sealing film 32. Yes. The fixing plate 33 is thicker than the sealing film 32 and is made of a harder material (for example, stainless steel). Since the region of the fixing plate 33 facing the reservoir is an opening 33a penetrating in the thickness direction, one surface of the reservoir is sealed only with a flexible sealing film 32. In addition, a wiring opening 34 that penetrates the sealing plate 13 in the thickness direction is formed in the sealing plate 13 between the accommodation space 29 and the liquid chamber space 30. The other end of the lead electrode 20 whose one end is connected to the lower electrode film 25 of the piezoelectric element 19 in the accommodation space 29 is exposed in the wiring opening 34. A terminal of a wiring member such as COF (Chip On Film) (not shown) from the printer main body side is electrically connected to the exposed portion of the lead electrode 20. The lower surface of the sealing plate 13 is bonded to the upper surface of the flow path forming substrate 10 on which the actuator unit 12 is laminated by an adhesive. The adhesive is made of, for example, an epoxy or urethane adhesive, and is applied to the lower surface of the sealing plate 13 in advance by transfer.

  In the recording head 2 configured as described above, ink is taken into the reservoir 16 from the ink cartridge 3 through the liquid chamber empty portion 30 and the like, and the flow path from the reservoir 16 to the nozzle 18 through the pressure chamber 15 is filled with ink. Then, by supplying a drive signal from the printer main body side, an electric field corresponding to the potential difference between the two electrodes is applied between the lower electrode film 25 and the upper electrode film 27 corresponding to the pressure chamber 15, and the piezoelectric element 19 and When the working surface of the vibration plate 14 is bent and deformed, pressure fluctuation occurs in the ink in the pressure chamber 15. By controlling the pressure fluctuation, ink can be ejected from the nozzle 18 or the meniscus in the nozzle 18 can be slightly vibrated to the extent that ink is not ejected.

  4 to 10 are process diagrams for explaining the manufacturing process of the recording head 2. First, as shown in FIG. 4, an elastic film is formed on the entire surface of a first wafer 40 (corresponding to the first substrate in the present invention) for a flow path forming substrate in which regions to be a plurality of flow path forming substrates 10 are partitioned. 21 is formed, and then the insulating film 22, the piezoelectric element 19, and the lead electrode 20 are sequentially formed on the elastic film 21 on one surface of the first wafer 40 (surface to be bonded to the sealing plate 13). Is done. In addition, since the manufacturing method of each of these layers is a well-known technique, detailed description is abbreviate | omitted. In the following, illustration of the piezoelectric elements 19 and the like is omitted as appropriate. The upper and lower surfaces of the first wafer 40, that is, the surface (first surface) to which the nozzle plate 11 is bonded, and the surface (second surface) to which the second wafer 41 to be the sealing plate 13 is bonded, respectively. A chamfered portion 42 is formed in advance on the outer peripheral edge of the. In the present embodiment, the diameter of the first wafer 40 (excluding a portion passing through an orientation flat (hereinafter referred to as an orientation flat)) D1 is 149 mm (see FIG. 7), whereas the diameter of the chamfered portion 42 is The dimension d1 is about 50 [μm] to 350 [μm]. Moreover, the diameter D2 of the 2nd wafer 41 joined with the 1st wafer 40 is 150 [mm] (refer FIG. 7). That is, the dimensional difference (D2-D1) between the first wafer 40 and the second wafer 41 is 1 [mm]. This point will be described later. In each figure, the dimensional ratio of each part of the wafers 40 and 41 may be different from the actual one.

  Next, as shown in FIG. 5, the second wafer 41 for the sealing plate 13 is divided into a plurality of regions to be the sealing plate 13 having the accommodation empty portion 29, the liquid chamber empty portion 30, and the wiring opening 34. Is done. A chamfered portion 43 is also provided in advance on the outer peripheral edge of the second wafer 41. Subsequently, as shown in FIG. 6, an alignment process for determining a relative position between the first wafer 40 and the second wafer 41 is performed. A first alignment mark 44 and a second alignment mark 45 are formed in advance on the bonding surface (second surface) of the first wafer 40 with the second wafer 41. These alignment marks 44 and 45 are, for example, parallelogram-shaped marks formed on the first wafer 40 by wet etching. The alignment marks 44 and 45 are oriented in a region outside the region where the plurality of flow path forming substrates 10 are partitioned. Are formed on one side and the other side in the surface direction. These alignment marks 44 and 45 may penetrate the first wafer 40 or may not penetrate. Moreover, it is not restricted to what was formed by wet etching, For example, what was formed by plating etc. may be used. In short, any mark may be used as a reference for alignment between the first wafer 40 and the second wafer 41. The position of the first wafer 40 and the second wafer 41 in the direction perpendicular to the orientation flat surface is defined with reference to the orientation flat.

  On the other hand, at the position corresponding to the first alignment mark 44 and the second alignment mark 45 of the first wafer 40 in the second wafer 41, the first alignment opening 46 and the second alignment opening 47 respectively have a plate thickness direction. It is formed in a penetrating state. Then, in the alignment step, the first wafer 40 and the second wafer 41 are parallel to the orientation flat based on the alignment marks 44 and 45 in a state where the bonding surfaces of the first wafer 40 and the second wafer 41 face each other. And the relative position in the direction parallel to the upper and lower surfaces of each wafer 40, 41 (position adjustment direction; hereinafter referred to as the first direction) is determined. Specifically, for example, as shown in FIG. 6, the alignment mark 44 of the first wafer 40 is passed through the alignment openings 46 and 47 of the second wafer 41 by a camera 48 (imaging means) disposed below the second wafer 41. , 45 are recognized, and the relative positions are adjusted so that the alignment marks 44, 45 are disposed in the alignment openings 46, 47, respectively. The alignment error will be described later with reference to FIG.

  If the relative position between the first wafer 40 and the second wafer 41 is determined in the alignment process, the first wafer 40 and the second wafer 41 may have the adhesive 49 interposed therebetween in the substrate bonding process as shown in FIG. And bonded (bonded) together. If the first wafer 40 and the second wafer 41 are joined, as shown in FIG. 8, in the grinding process, the first wafer 40 and the second wafer 41 opposite to the second face on which the second wafer 41 is joined are formed. By grinding one surface, the first wafer 40 is adjusted to a necessary thickness as the flow path forming substrate 10. Specifically, for example, the first wafer 40 is ground to some extent (until it is a little thicker than the necessary thickness) by a back surface polishing apparatus (back grinder) or the like. Thereafter, the first wafer 40 is wet-etched using, for example, an etching solution made of hydrofluoric acid or the like, so that the thickness required for the flow path forming substrate 10 is adjusted.

  After the first wafer 40 is ground to a predetermined thickness, a flow path such as the pressure chamber 15 is formed on the first wafer 40 by a photolithography process and an etching process, as shown in FIG. Specifically, a resist (not shown) is patterned into a predetermined shape on the first surface of the first wafer 40. Next, wet etching is performed from the first surface side of the first wafer 40 using, for example, an alkaline solution such as a potassium hydroxide (KOH) aqueous solution. As a result, the first wafer 40 is formed with empty portions that serve as the pressure chamber 15, the individual supply port 17, and the reservoir 16. Then, as shown in FIG. 10, the unnecessary part of the outer periphery part of the joined body of the 1st wafer 40 and the 2nd wafer 41 is removed by cutting by dicing etc., for example. Then, the nozzle plate 11 having the nozzles 18 formed on the first surface of the first wafer 40 is bonded, and the compliance substrate 31 is bonded to the second wafer 41. These first wafer 40 and the like are shown in FIG. The recording head 2 in the present embodiment is manufactured by being divided into such a single chip size.

  FIG. 11 is a schematic diagram for explaining an alignment error between the first wafer 40 and the second wafer 41. In the figure, the wafers 40 and 41 in a state where they are arranged at a specified position (design target position) in the alignment direction (first direction) of the alignment marks 44 and 45 are indicated by solid lines, and are located at a position higher than the specified position. Each of the wafers 40 and 41 in a state where the maximum allowable error in one direction is shifted is indicated by a broken line. Here, the alignment error in the first direction of the first wafer 40, that is, the tolerance with respect to the specified position is T1 [mm], and the tolerance in the first direction when the specified position is 0 (the positional deviation from the specified position). The allowable maximum value) is σ1 [mm]. That is, the tolerance (alignment accuracy) T1 for the alignment of the first wafer 40 is ± σ1. Similarly, the tolerance of the second wafer 41 with respect to the specified position in the first direction is T2 [mm], and the tolerance in the first direction when the specified position is 0 is σ2 [mm]. That is, the tolerance T2 for the alignment of the second wafer 41 is ± σ2. For convenience, in the first direction, a position shift on the side where one end of the first wafer 40 approaches one end of the second wafer 41 (left side in FIG. 11) is defined as a shift on the + side. A positional shift on the side (right side in FIG. 11) whose end is far from one end of the second wafer 41 is defined as a negative shift.

In this embodiment, the tolerance T1 with respect to the specified position of the first wafer 40 is ± 0.3 [mm], and | σ1 | is 0.3 [mm]. Similarly, the tolerance T2 with respect to the specified position of the second wafer 41 is ± 0.3 [mm], and | σ2 | is 0.3 [mm]. When the errors of the wafers 40 and 41 in the alignment process are allowable maximum values in the opposite directions in the first direction, that is, for example, one end of the first wafer 40 is shifted by + σ1 with respect to the specified position. 11 (position indicated by E1a in FIG. 11), and one end of the second wafer 41 is shifted by −σ1 from the specified position (position indicated by E2b in FIG. 11). In addition, the end of the first wafer 40 is configured not to protrude outward from the end of the second wafer 41. More specifically, the diameter D1 of the first wafer 40 and the diameter D2 of the second wafer 41 are set so as to satisfy the following condition (1).
D1-D2> 2 (σ1 + σ2) (1)
In this embodiment, since 2 × (0.3 + 0.3) = 1.2 [mm], when the diameter D2 of the second wafer 41 is 150 [mm], the diameter D1 of the first wafer 40 is It is set smaller than 148.8 [mm]. However, in the present embodiment, the diameter D1 of the first wafer 40 is set to 149 [mm] in consideration that the substantial alignment error is substantially smaller than the above-described tolerance.

  Thus, since the diameter D1 of the first wafer 40 and the diameter D2 of the second wafer 41 are set so as to satisfy the above condition (1), after the alignment process, the first wafer 40 In the state where the second wafer 41 is bonded, even if there is an alignment error, the outer peripheral end of the first wafer 40 is prevented from protruding outward from the outer peripheral end of the second wafer 41. Thus, the first wafer 40 (especially the end portion) can be processed during the processing of the first wafer 40 without increasing the number of steps for processing the recess for accommodating the first wafer 40 in the second wafer 41 as in the prior art. ) Is prevented from being chipped or cracked. In particular, when the first wafer 40 is ground and thinned as in the grinding step, cracks and chips are more likely to occur. In this case as well, the end of the first wafer 40 is the end of the second wafer 41. Since it does not protrude outward from the end, it is possible to effectively suppress cracking and chipping of the first wafer 40. As a result, the yield in the manufacturing process of the recording head 2 (MEMS device or laminated structure) can be improved. The upper limit of the dimensional difference between the diameter D1 of the first wafer 40 and the diameter D2 of the second wafer 41 is determined according to the number of flow path forming substrates 10 in the first wafer 40. In other words, the dimensional difference is determined in a range that satisfies the condition (1) and does not affect the number of the flow path forming substrates 10 in the first wafer 40.

  Although one embodiment of the present invention has been described above, of course, the present invention is not limited to such an embodiment. For example, the configuration of the piezoelectric element 19 and the configuration of the flow path (pressure chamber 15 and the like) formed on the flow path forming substrate 10 are not limited to those exemplified in the above embodiment, and various configurations may be adopted. Can do. In short, the present invention can be applied as long as it has a laminated structure in which a plurality of substrates (silicon wafers) are laminated and integrated.

  In the above-described embodiment, the ink jet recording head mounted on the liquid ejecting head ink jet printer is exemplified as one form of the MEMS device having the laminated structure. However, the present invention may be applied to one that ejects liquid other than ink. it can. For example, a color material ejecting head used for manufacturing a color filter such as a liquid crystal display, an electrode material ejecting head used for forming an electrode such as an organic EL (Electro Luminescence) display, FED (surface emitting display), a biochip (biochemical element) The present invention can also be applied to bioorganic matter ejecting heads and the like used in the production of

  DESCRIPTION OF SYMBOLS 1 ... Printer, 2 ... Recording head, 3 ... Ink cartridge, 4 ... Carriage, 6 ... Recording paper, 7 ... Carriage moving mechanism, 8 ... Paper feed mechanism, 10 ... channel forming substrate, 11 ... nozzle plate, 12 ... actuator unit, 13 ... sealing plate, 14 ... vibrating plate, 15 ... pressure chamber, 16 ... reservoir, 17 ... Individual supply port, 18 ... Nozzle, 19 ... Piezoelectric element, 20 ... Lead electrode, 21 ... Elastic film, 22 ... Insulating film, 23 ... Communication opening, 25 ... Lower electrode film, 26 ... Piezoelectric film, 27 ... Upper electrode film, 29 ... Storage cavity, 30 ... Liquid chamber cavity, 31 ... Compliance substrate, 32. .. Sealing film, 33 ... Fixing plate, 34 ... Wiring opening, 40 ... First wafer, 41 ... Second wafer, 42 ... Chamfer, 43 ... Chamfer 44 ... first alignment mark, 45 ... second alignment mark, 46 ... first Alignment opening, 47 ... second alignment opening, 48 ... camera, 49 ... adhesive

Claims (4)

An alignment step for determining a relative position between the first substrate and the second substrate;
A bonding step of bonding the first substrate and the second substrate with the relative position determined by the alignment step;
Have
The difference between the outer diameter of the first substrate and the outer diameter of the second substrate is the tolerance for the position of the first substrate and the tolerance for the position of the second substrate in the alignment step. Substrate bonding method characterized by being at least twice the total of the above.   The substrate bonding method according to claim 1, further comprising a grinding step of grinding the first substrate after the joining step. A method for manufacturing a MEMS device having a laminated structure formed by bonding a first substrate and a second substrate,
A method for manufacturing a MEMS device, comprising the substrate bonding method according to claim 1. A liquid ejecting head having a liquid channel communicating with a nozzle and a driving element for ejecting the liquid in the liquid channel from the nozzle to a laminated structure formed by bonding the first substrate and the second substrate A manufacturing method comprising:
A manufacturing method of a liquid jet head including the substrate bonding method according to claim 1.

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