JP2018047637A - Method for manufacturing mems device, and method for manufacturing liquid jet head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing an MEMS device which suppresses damage of an electrode and can suppress lowering of reliability, and to provide a method for manufacturing a liquid jet head.SOLUTION: A method for manufacturing an MEMS device (recording head 3) that is provided with a first substrate (sealing plate 33) having a resin part (38) protruding from one surface and a first electrode (lower surface side protective film 52) covering a part of the resin part and a second substrate (pressure chamber forming substrate 29) having a second electrode on a surface facing the one surface includes: a resin part forming step of forming the resin part on one surface of the first substrate; an electrode layer forming step of forming an electrode layer (metal layer 52') becoming the first electrode on one surface; and an electrode layer etching step of etching the electrode layer to form the first electrode, where the temperature of the first substrate in the electrode layer forming step is a temperature equal to or higher than the highest temperature of the first substrate in the electrode layer forming step.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a method for manufacturing a MEMS device including a resin and a bump electrode made of an electrode covering the surface of the resin, and a method for manufacturing a liquid jet head.

  2. Description of the Related Art A MEMS (Micro Electro Mechanical Systems) device including a bump electrode that electrically connects two substrates is applied to various apparatuses (for example, a liquid ejecting apparatus and a sensor). For example, a liquid jet head which is a kind of MEMS device includes an actuator such as the bump electrode and the piezoelectric element described above, and transmits a drive signal (electric signal) to the actuator via the bump electrode. Examples of the liquid ejecting apparatus on which such a liquid ejecting head is mounted include an image recording apparatus such as an ink jet printer and an ink jet plotter. Recently, a liquid ejecting head has been applied to various manufacturing apparatuses by taking advantage of the fact that a very small amount of liquid can be accurately landed at a predetermined position. 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), and 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.

  The bump electrode includes a resin layer formed on the surface of the substrate and an electrode (wiring) formed on the resin layer (see, for example, Patent Document 1). The bump electrode is connected to a terminal formed on the counter substrate in a state where the bump layer is pressed toward the counter substrate facing and the resin layer is crushed.

JP 2009-260389 A

  Here, in the manufacturing process of the MEMS device, if heat is applied to the bump electrode after the bump electrode is formed, the resin layer may expand, and the electrode formed on the resin layer may be damaged. That is, due to the expansion of the resin layer, tensile stress is applied to the electrode, and the electrode is cracked or cracked. For example, when a substrate on which a bump electrode is formed and a counter substrate opposite to the substrate are bonded with an adhesive, heat is transmitted to the resin layer when the substrate is heated to cure the adhesive, and the electrode May be damaged. And when an electrode is damaged, conduction | electrical_connection between a bump electrode and a terminal cannot be taken normally, but the reliability of a MEMS device falls.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a method for manufacturing a MEMS device and a method for manufacturing a liquid ejecting head that can suppress electrode breakage and suppress deterioration in reliability. It is to provide.

The manufacturing method of the MEMS device of the present invention is proposed in order to achieve the above object, and includes a resin portion made of resin protruding from one surface and a first electrode covering a part of the resin portion. A first substrate, and a second substrate having a second electrode on a surface opposite to the one surface, wherein the first substrate and the second substrate are the first electrode and the second substrate. A method of manufacturing a MEMS device joined to conduct with the second electrode,
A resin part forming step of forming the resin part on the one surface of the first substrate;
An electrode layer film forming step of forming an electrode layer serving as the first electrode on the one surface including the region where the resin portion is formed;
An electrode layer etching step of etching the electrode layer to form the first electrode;
Including
The temperature of the first substrate in the electrode layer deposition step is a temperature equal to or higher than the highest temperature of the first substrate after the electrode layer deposition step.

  According to this method, since the electrode layer is formed in a state where the resin portion is expanded, the resin portion contracts due to cooling after forming the electrode layer, and compressive stress is applied to the electrode layer laminated on the resin portion. Become working. That is, compressive stress remains as residual stress in the electrode layer laminated on the resin portion. Thereby, damage, such as a crack and a crack, in the electrode layer laminated | stacked on the resin part can be suppressed. In addition, since the resin portion when forming the electrode layer is in the most expanded state from the electrode layer forming step to the completion of the MEMS device, even if the resin portion expands again in the subsequent steps, the resin portion The electrode layer laminated on the part does not extend more than during film formation. Thereby, the damage of the electrode layer laminated | stacked on the resin part can be suppressed more reliably. As a result, a decrease in reliability of the MEMS device can be suppressed.

The method for manufacturing a MEMS device according to the present invention includes a first substrate having a resin portion made of a resin protruding from one surface and a first electrode covering a part of the resin portion, and facing the one surface. A second substrate having a second electrode on a surface to be bonded, and the first substrate and the second substrate are joined so as to make the first electrode and the second electrode conductive. A method for manufacturing a MEMS device, comprising:
A resin part forming step of forming the resin part on the one surface of the first substrate;
An electrode layer film forming step of forming an electrode layer serving as the first electrode on the one surface including the region where the resin portion is formed;
An electrode layer etching step of etching the electrode layer to form the first electrode;
A substrate bonding step of bonding the first substrate and the second substrate via an adhesive so as to make the first electrode and the second electrode conductive;
Including
The temperature of the first substrate in the electrode layer deposition step is higher than the temperature of the first substrate in the substrate bonding step.

  According to this method, since the electrode layer is formed in a state where the resin portion is expanded, the resin portion contracts due to cooling after forming the electrode layer, and compressive stress is applied to the electrode layer laminated on the resin portion. Become working. That is, compressive stress remains as residual stress in the electrode layer laminated on the resin portion. Thereby, damage, such as a crack and a crack, in the electrode layer laminated | stacked on the resin part can be suppressed. In addition, since the resin part when forming the electrode layer is in a state of expanding more than the resin part in the substrate bonding process, even if the resin part expands again in the substrate bonding process, the electrode layer laminated on the resin part is It doesn't grow longer than during film formation. Thereby, the damage of the electrode layer laminated | stacked on the resin part can be suppressed more reliably. As a result, a decrease in reliability of the MEMS device can be suppressed.

And the manufacturing method of the liquid jet head of the present invention is a method of manufacturing a liquid jet head provided with the structure of the MEMS device according to any one of the above manufacturing methods,
It goes through the manufacturing method of the MEMS device in any one of said each manufacturing method, It is characterized by the above-mentioned.

  According to this method, a decrease in the reliability of the liquid jet head can be suppressed.

FIG. 3 is a perspective view illustrating a configuration of a printer. FIG. 3 is a cross-sectional view illustrating a configuration of a recording head. FIG. 3 is an enlarged cross-sectional view of a main part of the recording head. FIG. 6 is a state transition diagram illustrating a method for manufacturing a recording head. FIG. 6 is a state transition diagram illustrating a method for manufacturing a recording head. FIG. 6 is a state transition diagram illustrating a method for manufacturing a recording head. FIG. 6 is a state transition diagram illustrating a method for manufacturing a recording head. FIG. 6 is a state transition diagram illustrating a method for manufacturing a recording head. FIG. 6 is a state transition diagram illustrating a method for manufacturing a recording head.

  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 following, a liquid ejecting head that is one category of MEMS devices, in particular, an ink jet recording head (hereinafter, recording head) 3 that is a kind of liquid ejecting head will be described as an example. FIG. 1 is a perspective view of an ink jet printer (hereinafter referred to as a printer) 1 which is a kind of liquid ejecting apparatus equipped with a recording head 3.

  The printer 1 is an apparatus that records an image or the like by ejecting ink (a type of liquid) onto the surface of a recording medium 2 (a type of landing target) such as a recording paper. The printer 1 includes a recording head 3, a carriage 4 to which the recording head 3 is attached, a carriage moving mechanism 5 that moves the carriage 4 in the main scanning direction, a conveyance mechanism 6 that transfers the recording medium 2 in the sub scanning direction, and the like. Yes. Here, the ink is stored in an ink cartridge 7 as a liquid supply source. The ink cartridge 7 is detachably attached to the recording head 3. It is also possible to employ a configuration in which the ink cartridge is disposed on the main body side of the printer and supplied from the ink cartridge to the recording head through the ink supply tube.

  The carriage moving mechanism 5 includes a timing belt 8. The timing belt 8 is driven by a pulse motor 9 such as a DC motor. Therefore, when the pulse motor 9 operates, the carriage 4 is guided by the guide rod 10 installed on the printer 1 and reciprocates in the main scanning direction (width direction of the recording medium 2). The position of the carriage 4 in the main scanning direction is detected by a linear encoder (not shown) which is a kind of position information detecting means. The linear encoder transmits the detection signal, that is, the encoder pulse (a kind of position information) to the control unit of the printer 1.

  Next, the recording head 3 will be described. FIG. 2 is a cross-sectional view illustrating the configuration of the recording head 3. FIG. 3 is an enlarged cross-sectional view of a main part of the recording head 3. 3 is an enlarged cross-sectional view of the periphery of the bump electrode 37 located at one end (left side in FIG. 2) of the recording head 3. In the following description, the stacking direction of the members will be described as the vertical direction as appropriate. As shown in FIG. 2, the recording head 3 in the present embodiment is attached to the head case 16 in a state where the actuator unit 14 and the flow path unit 15 are stacked.

  The head case 16 is a box-shaped member made of synthetic resin, and a liquid introduction path 18 for supplying ink to each pressure chamber 30 is formed therein. The liquid introduction path 18 is a space for storing ink common to a plurality of formed pressure chambers 30 together with a common liquid chamber 25 described later. In the present embodiment, two liquid introduction paths 18 are formed corresponding to the rows of pressure chambers 30 arranged in two rows. In addition, the lower part (the flow path unit 15 side) of the head case 16 is recessed in a rectangular parallelepiped shape from the lower surface of the head case 16 (the surface on the flow path unit 15 side) to the middle of the head case 16 in the height direction. An accommodating space 17 is formed. When a flow path unit 15 to be described later is joined in a state of being positioned on the lower surface of the head case 16, the actuator unit 14 (the pressure chamber forming substrate 29, the sealing plate 33, the drive IC 34, etc.) stacked on the communication substrate 24 is obtained. It is configured to be accommodated in the accommodating space 17. Although not shown, an opening that communicates the space outside the head case 16 and the accommodation space 17 is formed in a part of the ceiling surface of the accommodation space 17. A wiring board such as an FPC (flexible printed circuit board) (not shown) is inserted through the opening into the accommodation space 17 and connected to the actuator unit 14 in the accommodation space 17. For this reason, the accommodation space 17 is a space open to the atmosphere.

  The flow path unit 15 in the present embodiment includes a communication substrate 24 and a nozzle plate 21. The nozzle plate 21 is a silicon substrate bonded to the lower surface of the communication substrate 24 (the surface opposite to the pressure chamber forming substrate 29). In the present embodiment, the nozzle plate 21 seals the opening on the lower surface side of a space that becomes a common liquid chamber 25 described later. The nozzle plate 21 has a plurality of nozzles 22 arranged in a straight line (row shape). Two rows of nozzles 22 (that is, nozzle rows) including the plurality of nozzles 22 are formed on the nozzle plate 21. The nozzles 22 constituting each nozzle row are provided at regular intervals along the sub-scanning direction, for example, at a pitch corresponding to the dot formation density from the nozzle 22 on one end side to the nozzle 22 on the other end side. In addition, the nozzle plate is bonded to a region of the communication substrate that is inward from the common liquid chamber, and the opening on the lower surface side of the space serving as the common liquid chamber is sealed with a member such as a flexible compliance sheet. You can also.

  The communication substrate 24 is a silicon substrate that constitutes the upper part (portion on the head case 16 side) of the flow path unit 15. As shown in FIG. 2, the communication substrate 24 communicates with the liquid introduction path 18, and a common liquid chamber 25 in which ink common to each pressure chamber 30 is stored, and the liquid is introduced through the common liquid chamber 25. An individual communication path 26 that individually supplies ink from the path 18 to each pressure chamber 30 and a nozzle communication path 27 that connects the pressure chamber 30 and the nozzle 22 are formed by etching or the like. The common liquid chambers 25 are long empty portions along the nozzle row direction, and are formed in two rows corresponding to the rows of pressure chambers 30 arranged in two rows as shown in FIG. . A plurality of individual communication paths 26 and nozzle communication paths 27 are formed along the nozzle row direction.

  As shown in FIG. 2, the actuator unit 14 in this embodiment is formed into a unit by laminating a pressure chamber forming substrate 29, a vibration plate 31, a piezoelectric element 32 that is a kind of actuator, a sealing plate 33, a drive IC 34, and the like. In this state, it is bonded to the communication substrate 24. The actuator unit 14 is formed smaller than the accommodation space 17 so that it can be accommodated in the accommodation space 17.

  The pressure chamber forming substrate 29 is a silicon substrate that constitutes a lower portion of the actuator unit 14 (portion unit 15 side portion). A part of the pressure chamber forming substrate 29 is removed in the thickness direction by etching or the like, and a plurality of spaces to be the pressure chambers 30 are arranged in parallel along the nozzle row direction. The space is partitioned by the communication substrate 24 at the lower side and partitioned by the diaphragm 31 to form the pressure chamber 30. In addition, this space, that is, the pressure chamber 30 is formed in two rows corresponding to the nozzle rows formed in two rows. Each pressure chamber 30 is a hollow portion that is long in a direction orthogonal to the nozzle row direction, and the individual communication passage 26 communicates with one end portion in the longitudinal direction, and the nozzle communication passage 27 forms the other end portion. Communicate.

  The vibration plate 31 is a thin film member having elasticity, and is laminated on the upper surface of the pressure chamber forming substrate 29 (the surface opposite to the flow path unit 15 side). The diaphragm 31 seals the upper opening of the space to be the pressure chamber 30. In other words, the pressure chamber 30 is partitioned by the diaphragm 31. A portion of the diaphragm 31 corresponding to the pressure chamber 30 (specifically, an upper opening of the pressure chamber 30) functions as a displacement portion that displaces in a direction away from or close to the nozzle 22 as the piezoelectric element 32 is bent and deformed. To do. That is, a region corresponding to the upper opening of the pressure chamber 30 in the diaphragm 31 is a drive region 35 in which bending deformation is allowed. On the other hand, a region outside the upper opening of the pressure chamber 30 in the diaphragm 31 is a non-driving region 36 in which bending deformation is inhibited. Note that the pressure chamber forming substrate 29 on which the vibration plate 31 is laminated, that is, the substrate including the vibration plate 31 and the pressure chamber forming substrate 29 corresponds to the second substrate in the present invention.

The vibration plate 31 is, for example, an elastic film made of silicon dioxide (SiO ₂ ) formed on the upper surface of the pressure chamber forming substrate 29 and an insulator made of zirconium oxide (ZrO ₂ ) formed on the elastic film. And a membrane. Then, the piezoelectric elements 32 are stacked in regions corresponding to the pressure chambers 30 on the insulating film (the surface opposite to the pressure chamber forming substrate 29 side of the vibration plate 31), that is, in the driving region 35. The piezoelectric element 32 in the present embodiment is a so-called flexural mode piezoelectric element. The piezoelectric element 32 is formed by, for example, sequentially laminating a lower electrode layer, a piezoelectric layer, and an upper electrode layer on the vibration plate 31. Either the upper electrode film or the lower electrode film is a common electrode formed in common for each piezoelectric element 32, and the other is an individual electrode formed individually for each piezoelectric element 32. When an electric field corresponding to the potential difference between the two electrodes is applied between the lower electrode layer and the upper electrode layer, the piezoelectric element 32 bends and deforms in a direction away from or near to the nozzle 22. Note that the piezoelectric elements 32 in the present embodiment are formed in two rows along the nozzle row direction corresponding to the pressure chambers 30 arranged in two rows along the nozzle row direction.

  Further, as shown in FIGS. 2 and 3, wiring 40 connected to the individual electrode or the common electrode of the piezoelectric element 32 is formed on the diaphragm 31. The wiring 40 extends to the non-drive region 36 of the diaphragm 31, and becomes a terminal connected to a bump electrode 37 (described later) in the non-drive region 36. That is, as shown in FIG. 2, in the non-driving region 36 on the upper surface of the diaphragm 31 (the surface facing the sealing plate 33), individual terminals 41 connected to the individual electrodes of the piezoelectric element 32 (first in the present invention). 2) and a common terminal 42 (a type of the second electrode in the present invention) connected to the common electrode of the piezoelectric element 32 is formed. Specifically, in the direction orthogonal to the nozzle row direction, individual terminals 41 are formed outside the row of one piezoelectric element 32 and outside the row of the other piezoelectric element 32, and are common between the rows of both piezoelectric elements 32. A terminal 42 is formed. The individual terminals 41 are formed for each piezoelectric element 32 because they are connected to the individual electrodes of the piezoelectric element 32. For example, a plurality of individual terminals 41 are formed along the nozzle row direction. On the other hand, at least one common terminal 42 is formed to be connected to the common electrode of the piezoelectric element 32. In the present embodiment, the common terminal 42 is connected to both the common electrode of one piezoelectric element 32 and the common electrode of the other piezoelectric element 32.

  As shown in FIGS. 2 and 3, the sealing plate 33 (corresponding to the first substrate in the present invention) is a photosensitive adhesive 43 having an insulating property between the sealing plate 33 (the adhesive of the present invention). 1 is a silicon substrate disposed at a distance from the diaphragm 31 with a single type) interposed therebetween. A bump electrode 37 that outputs a drive signal from the drive IC 34 to the piezoelectric element 32 side is provided on the lower surface (corresponding to one surface in the present invention) of the sealing plate 33 on the pressure chamber forming substrate 29 side in the present embodiment. A plurality of are formed. As shown in FIG. 2, the bump electrode 37 is located at a position corresponding to one individual terminal 41 formed outside one piezoelectric element 32, and the other individual terminal 41 formed outside the other piezoelectric element 32. , A position corresponding to the common terminal 42 formed between the rows of both piezoelectric elements 32, and the like. Each bump electrode 37 is connected to a corresponding individual terminal 41 or common terminal 42. More specifically, a conductive film 39 (the lower surface side protective film 52 and the lower surface side metal film 53) described later is electrically connected to the corresponding individual terminal 41 or common terminal 42. Note that the sealing plate 33 and the pressure chamber forming substrate 29 were pressurized in a direction in which the bump electrodes 37 and the individual terminals 41 and the corresponding common terminals 42 corresponding to the bump electrodes 37 approach each other. It is joined in a state.

  As shown in FIG. 3, the bump electrode 37 in the present embodiment includes a resin portion 38 made of resin protruding from the lower surface of the sealing plate 33, and the surface of the resin portion 38 (specifically, on the lower surface of the sealing plate 33. This is a so-called resin core bump made of a conductive film 39 that covers a part of the surface on the side opposite to the contacting surface. The resin portion 38 is made of an elastic resin made of, for example, a polyimide resin, a phenol resin, an epoxy resin, or the like, and is formed on the bottom surface of the sealing plate 33 in a protruding shape along the nozzle row direction. As shown in FIG. 3, the resin portion 38 has a lower surface formed in an arc shape in a cross section in a direction intersecting the nozzle row direction. The conductive film 39 is formed by laminating a lower surface side protective film 52 (corresponding to the first electrode in the present invention) and a lower surface side metal film 53 in order from the lower surface side of the sealing plate 33. The lower surface side protective film 52 is made of, for example, titanium (Ti), nickel (Ni), chromium (Cr), tungsten (W), alloys thereof, or a laminate of these, and has corrosion resistance and conductivity. Have. The lower surface side metal film 53 is made of gold (Au) or the like. For this reason, the lower surface side protective film 52 functions not only as a protective film that protects the through wiring 45 described later, but also as an adhesion layer that improves the adhesion of the lower surface side metal film 53.

  Such a two-layer conductive film 39 is formed at a position corresponding to the individual terminal 41 or the common terminal 42 on the surface of the resin portion 38. Specifically, a plurality of conductive films 39 of the bump electrodes 37 that are electrically connected to the individual terminals 41 are formed along the nozzle row direction corresponding to the individual terminals 41 arranged in parallel along the nozzle row direction. . In addition, at least one conductive film 39 conducting to the common terminal 42 is formed corresponding to the common terminal 42. The resin portion 38 is connected to the individual terminal 41 or the common terminal 42 with the conductive film 39 (the lower surface side protective film 52 and the lower surface side metal film 53) sandwiched therebetween and slightly collapsed in the height direction. Yes. That is, the bump electrode 37 is connected to the individual terminal 41 or the common terminal 42 in a state of being slightly crushed in the height direction.

  Further, as shown in FIG. 3, the conductive film 39 extends along the direction intersecting the nozzle row direction to the position where it overlaps with the through wiring 45 formed at a position off the resin portion 38 on the lower surface of the sealing plate 33. Has been extended. That is, the conductive film 39 extends in a direction intersecting with the nozzle row direction from a position overlapping the end on the lower surface side of the through wiring 45 to a position overlapping the resin portion 38. The end on the lower surface side of the through wiring 45 is covered with the conductive film 39 (that is, the lower surface side protective film 52) and is electrically connected to the conductive film 39. In the present embodiment, the through wiring 45 formed on one side of the bump electrode 37 and the through wiring 45 formed on the other side of the bump electrode 37 are alternately arranged along the nozzle row direction. Correspondingly, the conductive film 39 drawn to one side from the position overlapping the resin portion 38 and the conductive film 39 drawn to the other side from the position overlapping the resin portion 38 are alternately arranged along the nozzle row direction. ing.

  As shown in FIGS. 2 and 3, the through wiring 45 is a wiring that relays between the lower surface and the upper surface of the sealing plate 33, and is provided inside the through hole 49 that penetrates the sealing plate 33 in the plate thickness direction. It consists of metal (conductor), such as formed copper (Cu). The through hole 49 in the present embodiment is formed at a position corresponding to a sealing space 44 (described later) formed between the pressure chamber forming substrate 29 and the sealing plate 33. That is, the through wiring 45 is arranged so that the lower surface side end faces the sealed space 44. As described above, a portion of the through wiring 45 exposed at the opening on the lower surface side of the through hole 49 (in other words, an end on the lower surface side of the through wiring 45) is covered with the corresponding conductive film 39. On the other hand, a portion of the through wire 45 exposed at the opening on the upper surface side of the through hole 49 (in other words, an end on the upper surface side of the through wire 45) is covered with the corresponding upper surface side wire 46. By the through wiring 45, the conductive film 39 extending from the bump electrode 37 and the upper surface side wiring 46 are electrically connected. The through wiring 45 does not need to be filled in the through hole 49, and may extend from the upper surface of the sealing plate 33 to the lower surface of the sealing plate 33 in at least a part of the through hole 49.

  The upper surface side wiring 46 is a wiring laminated on the upper surface of the sealing plate 33 (the surface on the driving IC 34 side (the side opposite to the pressure chamber forming substrate 29 side)). The upper surface side wiring 46 is formed by laminating an upper surface side protective film 55 and an upper surface side metal film 56 in order from the upper surface side of the sealing plate 33. The upper surface side protective film 55 is made of the same metal as that of the lower surface side protective film 52. For example, titanium (Ti), nickel (Ni), chromium (Cr), tungsten (W), alloys thereof, and the like are laminated. It consists of what was done. For this reason, the upper surface side protective film 55 also has corrosion resistance and electrical conductivity, like the lower surface side protective film 52. The upper surface side metal film 56 is made of the same metal as the lower surface side metal film 53, and is made of gold (Au) or the like. The upper surface side protective film 55 functions as a protective film that protects the through wiring 45 as well as the lower surface side metal film 53, and also functions as an adhesion layer that improves the adhesion of the upper surface side metal film 56. The upper surface side wiring 46 extends from a position covering the upper surface side end of the through wiring 45 to a position corresponding to an IC terminal 47 of the drive IC 34 described later, and a terminal portion connected to the IC terminal 47 at the position. Become.

  The photosensitive adhesive 43 that bonds the sealing plate 33 and the pressure chamber forming substrate 29 (more specifically, the vibration plate 31 laminated on the pressure chamber forming substrate 29) has a photosensitivity that changes its degree of curing when irradiated with light. And it is the adhesive which has thermosetting which changes a hardening degree by heating. As such a photosensitive adhesive 43, for example, a resin mainly containing an epoxy resin, an acrylic resin, a phenol resin, a polyimide resin, a silicone resin, a styrene resin, or the like is preferably used. Further, as shown in FIG. 2, the photosensitive adhesive 43 in the present embodiment is provided on the outer peripheral portion of the sealing plate 33 and on both sides of the bump electrode 37 in the direction orthogonal to the nozzle row direction. Then, a sealing space 44 is formed between the sealing plate 33 and the pressure chamber forming substrate 29 by the photosensitive adhesive 43 provided on the outer peripheral portion of the sealing plate 33. That is, the sealing space 44 is partitioned by the sealing plate 33, the pressure chamber forming substrate 29 (vibrating plate 31), and the photosensitive adhesive 43 provided on the outer peripheral portion of the sealing plate 33. For this reason, the piezoelectric element 32 is accommodated in the sealing space 44. The sealed space 44 is not a completely sealed space because it is opened to the atmosphere via a small-diameter atmosphere opening path (not shown) that penetrates the sealing plate 33. In addition, the photosensitive adhesive 43 provided on both sides of the bump electrode 37 is formed to be long along the extending direction of the resin portion 38.

  A drive IC 34 is stacked on the upper surface of the sealing plate 33. The drive IC 34 is an IC chip for driving the piezoelectric element 32, and is fixed to the upper surface of the sealing plate 33 via an adhesive 48 such as an anisotropic conductive film (ACF). As shown in FIG. 2, a plurality of IC terminals 47 connected to the terminal portions of the upper surface side wiring 46 are formed on the lower surface (surface on the sealing plate 33 side) of the drive IC 34. Among the IC terminals 47, a plurality of IC terminals 47 corresponding to the individual terminals 41 are arranged in parallel along the nozzle row direction. In this embodiment, two rows of IC terminals 47 are formed corresponding to the rows of piezoelectric elements 32 arranged in two rows.

  The recording head 3 configured as described above introduces ink from the ink cartridge 7 into the pressure chamber 30 via the liquid introduction path 18, the common liquid chamber 25, the individual communication path 26, and the like. In this state, if a drive signal from the drive IC 34 is supplied to the piezoelectric element 32 via the bump electrode 37, the wiring 40, etc., the piezoelectric element 32 is driven and pressure fluctuation occurs in the ink in the pressure chamber 30. By using this pressure fluctuation, the recording head 3 ejects ink droplets from the nozzles 22.

  Next, a manufacturing method of the recording head 3, particularly a manufacturing method of the sealing plate 33 will be described in detail. 4 to 10 are state transition diagrams for explaining a method of manufacturing the recording head 3. In particular, FIGS. 4 to 9 are state transition diagrams illustrating a method for manufacturing the sealing plate 33. 4 to 10 are shown upside down with respect to FIGS. 2 and 3 for convenience of explanation. That is, in FIGS. 4 to 10, the lower surface side (pressure chamber forming substrate 29 side) of the sealing plate 33 is the upper side, and the upper surface side (drive IC 34 side) is the lower side.

  First, the through wiring 45 is formed at a predetermined position on a silicon substrate (hereinafter, simply referred to as a sealing plate 33) to be the sealing plate 33. Specifically, the through hole 49 penetrating the sealing plate 33 in the thickness direction is formed by, for example, dry etching, wet etching, laser, or a combination of these methods. Then, the through wiring 45 is formed inside the through hole 49 by electrolytic plating or the like. The metal deposited outside the upper surface or the lower surface of the sealing plate 33 is removed using a CMP (Chemical Mechanical Polishing) method or the like. Next, in the resin portion forming step, the resin portion 38 is formed on the lower surface of the sealing plate 33 (the upper surface in FIG. 4). Specifically, for example, a resin layer is formed on the surface of the sealing plate 33, and a resin layer is formed at a predetermined position through a photolithography process or the like. That is, a resin layer having a rectangular cross section extending along the nozzle row direction is formed. If such a resin layer is formed, the sealing plate 33 is heated. Due to this heat, the viscosity of the resin layer is lowered and the corners of the resin layer fall. Thereafter, the sealing plate 33 is cooled to solidify the resin layer. As a result, as shown in FIG. 4, a resin portion 38 having a circular arc surface is formed.

  Next, a conductive film 39 is formed on the resin portion 38. Specifically, as shown in FIG. 5, first, in the first film forming step (corresponding to the electrode layer forming step in the present invention), the lower surface of the sealing plate 33 including the region where the resin portion 38 is formed. A metal layer 52 ′ (corresponding to the electrode layer in the present invention) to be the lower surface side protective film 52 is formed on the entire surface (the upper surface in FIG. 5). At this time, sealing is performed so that the temperature is higher than the highest temperature (for example, 200 ° C. to 230 ° C.) reached by the sealing plate 33 in the manufacturing process after the first film forming process until the recording head 3 is completed. A metal layer 52 ′ is formed with heat applied to the plate 33. That is, the temperature of the sealing plate 33 in the first film forming step is equal to or higher than the highest temperature of the sealing plate 33 after the first film forming step. In particular, this temperature (the temperature of the first substrate in the first film forming step) is higher than the temperature of the sealing plate 33 in the substrate bonding step (described later) that tends to be high. In other words, heat is applied to the sealing plate 33 so that the temperature is higher than the highest temperature reached by the sealing plate 33 in the substrate bonding step. Specifically, for example, the metal layer 52 ′ is formed by sputtering or the like in a state where heat is applied to the stage on which the sealing plate 33 is placed. Thus, the resin part 38 will be in the expanded state by applying heat to the sealing plate 33. In this state, by forming the metal layer 52 ′ by a sputtering method or the like, a dense metal layer 52 ′ can be formed as compared with the case where heat is not applied to the sealing plate 33. Subsequently, as shown in FIG. 6, in the second film formation step, a metal layer 53 ′ that becomes the lower surface side metal film 53 is formed on the metal layer 52 ′ that becomes the lower surface side protection film 52. For example, similarly to the metal layer 52 ′ that becomes the lower surface side protective film 52, the sealing plate 33 is placed on the stage, and the metal layer 53 ′ is formed by sputtering or the like. At this time, the temperature of the sealing plate 33 is adjusted to be equal to or lower than the temperature of the sealing plate 33 in the first film forming step. In the present embodiment, the metal layer 53 ′ to be the lower surface side metal film 53 is formed by a sputtering method or the like while the stage is heated so that the sealing plate 33 has the same temperature as the first film formation step. Thereby, since it can suppress that the resin part 38 expand | swells rather than the time of a 1st film-forming process, it can suppress that metal layer 52 'used as the lower surface side protective film 52 is damaged. Further, a denser metal layer 53 ′ can be formed than when no heat is applied to the sealing plate 33.

  If the metal layer 52 ′ to be the lower surface side protective film 52 and the metal layer 53 ′ to be the lower surface side metal film 53 are formed on the surface of the sealing plate 33, heating of the sealing plate 33 is stopped, and the sealing plate Cool the temperature of 33 to room temperature. As a result, the expanded resin portion 38 contracts, and compressive stress is applied to the metal layer 52 ′ that becomes the lower surface side protective film 52 and the metal layer 53 ′ that becomes the lower surface side metal film 53 laminated on the resin portion 38. It becomes a state. That is, the compressive stress remains as residual stress in the metal layer 52 ′ that becomes the lower surface side protective film 52 and the metal layer 53 ′ that becomes the lower surface side metal film 53. Thereafter, in the first metal layer etching step (corresponding to the electrode layer etching step in the present invention), the metal layer 52 ′ to be the lower surface side protective film 52 and the metal layer 53 ′ to be the lower surface side metal film 53 are etched to form the lower surface. The side protective film 52 and the lower surface side metal film 53 (that is, the conductive film 39) are formed. Specifically, a resist layer is formed on the metal layer 53 ′ to be the lower surface side metal film 53, and the metal layer 52 ′ and the lower surface side metal film to be the lower surface side protective film 52 through a photolithography process, an etching process, and the like. The metal layer 53 ′ that becomes 53 is etched. Thereby, as shown in FIG. 7, the conductive film 39 (the lower surface side protective film 52 and the lower surface side metal film 53) is formed at a predetermined position, and the bump electrode 37 is formed.

  If the bump electrodes 37 and the like are formed on the lower surface of the sealing plate 33, the upper surface side wiring 46 and the like are formed on the upper surface (the lower surface in FIG. 8) of the sealing plate 33 as shown in FIG. Specifically, in the third film forming step, a metal layer to be the upper surface side protective film 55 is formed on the entire upper surface of the sealing plate 33, and in the fourth film forming step, the upper surface side protective film 55 is formed. A metal layer to be the upper surface side metal film 56 is formed on the metal layer to be. In the third film formation step and the fourth film formation step, the metal layer may be formed with the sealing plate 33 heated, or the metal layer may be formed without heating the sealing plate 33. A film may be formed. When the sealing plate 33 is heated, the temperature of the sealing plate 33 is adjusted so as to be equal to or lower than the temperature of the sealing plate 33 in the first film formation step. In the case where the sealing plate 33 is not heated, even if the sealing plate 33 is heated by film formation by sputtering, the temperature of the sealing plate 33 at this time is the same as that in the first film forming step. It becomes lower than the temperature of 33. Thereafter, in the second metal layer etching step, the metal layer to be the upper surface side protective film 55 and the metal layer to be the upper surface side metal film 56 are etched to form the upper surface side protective film 55 in the same manner as in the first metal layer etching step. And the upper surface side metal film 56 (that is, the upper surface side wiring 46) is formed. Thereby, as shown in FIG. 8, the upper surface side wiring 46 etc. are formed in a predetermined position, and the sealing board 33 is created. In addition, as a manufacturing method of the sealing board 33, it is not restricted to said method. For example, the upper surface side wiring 46 or the like may be formed on the upper surface of the sealing plate 33 first, and the bump electrode 37 or the like may be formed on the lower surface of the sealing plate 33 later.

  If the sealing plate 33 is formed as described above, the photosensitive adhesive 43 is provided between the pressure chamber forming substrate 29 on which the piezoelectric element 32 and the vibration plate 31 are formed and the sealing plate 33 in the substrate bonding step. The photosensitive adhesive 43 is heated in a state where the is sandwiched, and the photosensitive adhesive 43 is cured. Specifically, first, a liquid photosensitive adhesive is applied to the surface of either the pressure chamber forming substrate 29 or the sealing plate 33 using, for example, a spin coater, and then heated. A photosensitive adhesive layer cured to a certain degree of hardness is formed. Next, in the exposure step, the photosensitive adhesive layer is irradiated with light such as ultraviolet rays to increase the degree of curing of the photosensitive adhesive layer at a predetermined position, and then in the development step, the other photosensitive adhesive layer Remove. Thereby, the photosensitive adhesive 43 is formed in a predetermined position. Next, as shown in FIG. 9, the pressure chamber forming substrate 29 and the sealing plate 33 are opposed to each other with the photosensitive adhesive 43 interposed therebetween, and the pressure chamber forming substrate 29 and the sealing plate 33 are brought closer to each other. Press (pressurize) in the direction and heat. By this pressing, the photosensitive adhesive 43 and the bump electrode 37 are crushed in the height direction, and the bump electrode 37 is electrically connected to the individual terminal 41 and the common terminal 42 corresponding thereto. Then, the photosensitive adhesive 43 is fully cured by heating, and the pressure chamber forming substrate 29 and the sealing plate 33 are joined. The heating for curing the photosensitive adhesive 43 may be performed from the pressure chamber forming substrate 29 side or from the sealing plate 33 side. Alternatively, it may be performed from both sides of the pressure chamber forming substrate 29 side and the sealing plate 33 side. In any case, the temperature of the sealing plate 33 rises due to heating, but the temperature of the sealing plate 33 at this time is equal to or lower than the temperature of the sealing plate 33 in the first film formation step described above. For example, the temperature of the sealing plate 33 is 170 ° C. to 200 ° C. For this reason, even if the resin part 38 expand | swells, it does not expand more than the resin part 38 at the time of a 1st film-forming process.

  When the photosensitive adhesive 43 is fully cured, pressing and heating are stopped, and the bonded pressure chamber forming substrate 29 and the sealing plate 33 are cooled to room temperature. Thereafter, the pressure chamber forming substrate 29 is polished from the lower surface side (the side opposite to the sealing plate 33 side) to make the pressure chamber forming substrate 29 thinner. Next, the pressure chamber 30 is formed on the thin pressure chamber forming substrate 29 through a photolithography process, an etching process, and the like. When the pressure chamber 30 is formed on the pressure chamber forming substrate 29, the driving IC 34 is joined to the sealing plate 33, and the actuator unit 14 is created. Then, after the actuator unit 14 and the flow path unit 15 are joined, the flow path unit 15 to which the actuator unit 14 is joined is joined to the lower surface of the head case 16. Thereby, the actuator unit 14 is accommodated in the accommodating space 17, and the above-described recording head 3 is produced.

  In this way, in a state where heat is applied to the sealing plate 33 so that the temperature is equal to or higher than the highest temperature of the sealing plate 33 in the manufacturing process after the first film formation process until the recording head 3 is completed. Since the metal layer 52 ′ to be the lower surface side protective film 52 is formed, the metal layer 52 ′ is formed with the resin portion 38 expanded. For this reason, the resin part 38 contracts by cooling after the metal layer 52 ′ is formed, and a compressive stress is applied to the metal layer 52 ′ laminated on the resin part 38. That is, the compressive stress remains as residual stress in the metal layer 52 ′ laminated on the resin portion 38. Thereby, damage, such as a crack and a crack, in metal layer 52 'laminated | stacked on the resin part 38 can be suppressed. Further, since the resin portion 38 when forming the metal layer 52 ′ is in the most expanded state from the first film formation step until the recording head 3 is completed, the resin portion 38 is again formed in the subsequent steps. Even if it expands, the metal layer 52 ′ laminated on the resin portion 38 does not extend more than during film formation. Thereby, damage to metal layer 52 'laminated | stacked on the resin part 38 can be suppressed more reliably. As a result, a decrease in the reliability of the recording head 3 can be suppressed, and consequently a decrease in the reliability of the printer 1 can be suppressed. In the present embodiment, the metal layer 52 ′ and the lower surface side metal film 53, which become the lower surface side protective film 52, are added to the sealing plate 33 so that the temperature is higher than the temperature of the sealing plate 33 in the substrate bonding step. Since the metal layer 53 ′ is formed, the resin portion 38 is expanded more than the resin portion 38 in the substrate bonding step. Thereby, even if the resin part 38 expands again in the substrate bonding step, the metal layer 52 ′ and the metal layer 53 ′ laminated on the resin part 38 do not extend more than at the time of film formation, and are laminated on the resin part 38. Further, damage to the metal layer 52 'and the metal layer 53' can be more reliably suppressed.

  The temperature applied to the sealing plate 33 in the first film forming step is not particularly limited as long as it is equal to or higher than the highest temperature of the sealing plate 33 after the first film forming step. It is desirable to exceed Tg (glass transition temperature). If the resin portion 38 exceeds Tg, the deformation amount (expansion amount) of the resin portion 38 increases, and if the metal layer 52 ′ that becomes the lower surface side protective film 52 is formed in this state, the resin portion 38 becomes more The metal layer 52 'can be formed in the expanded state. For this reason, even if the sealing plate 33 is heated in the subsequent process, if the temperature of the sealing plate 33 at this time does not exceed Tg, the crack of the metal layer 52 ′ laminated on the resin portion 38 will occur. It is possible to further suppress cracks and the like. In the case where the metal layer 52 ′ is formed in a state where the sealing plate 33 is heated to a temperature not exceeding the Tg of the resin portion 38, the above Tg is used from the viewpoint of suppressing cracks and cracks in the metal layer 52 ′. Although it is inferior in the case of heating beyond the range, it has an effect of suppressing the peeling of the metal layer 52 '. That is, when the resin portion 38 does not exceed Tg, the deformation amount of the resin portion 38 when changing from a state expanded by heating to a state contracted by cooling can be suppressed, and the metal layer 52 ′ is peeled off due to excessive deformation. Can be suppressed.

  By the way, in above-mentioned embodiment, although the bump electrode 37 was formed in the sealing plate 33 side, it is not restricted to this. For example, a bump electrode may be formed on the pressure chamber forming substrate side. In this case, the substrate including the vibration plate and the pressure chamber forming substrate corresponds to the first substrate in the present invention, and the sealing plate corresponds to the second substrate in the present invention. Further, the step of forming a metal layer on the resin portion of the pressure chamber forming substrate corresponds to the film forming step in the present invention. Even in this case, the pressure chamber forming substrate is formed so that the pressure chamber forming substrate has a temperature equal to or higher than the highest temperature in the manufacturing process from the step of forming the metal layer on the resin portion to the completion of the recording head. A metal layer is formed with heat applied. In particular, in the substrate bonding step, the metal layer is formed in a state where heat is applied to the pressure chamber forming substrate so that the temperature becomes equal to or higher than the highest temperature reached by the pressure chamber forming substrate. Thereby, damage to the metal layer can be suppressed.

  In the above-described embodiment, the conductive film 39 of the bump electrode 37 is configured by two layers of the lower surface side protective film 52 and the lower surface side metal film 53, but is not limited thereto. For example, this conductive film may be formed of a single layer. In this case, the conductive film corresponds to the first electrode in the present invention, and the metal layer to be the conductive film corresponds to the electrode layer in the present invention.

  In the above description, the ink jet recording head 3 has been described as an example of the liquid ejecting head, but the present invention can also be applied to other liquid ejecting heads. 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 In a color material ejecting head for a display manufacturing apparatus, a solution of each color material of R (Red), G (Green), and B (Blue) is ejected as a kind of liquid. Further, an electrode material ejecting head for an electrode forming apparatus ejects a liquid electrode material as a kind of liquid, and a bioorganic matter ejecting head for a chip manufacturing apparatus ejects a bioorganic solution as a kind of liquid.

  In addition, a first substrate and a second substrate are provided, and a bump electrode including a resin portion and an electrode covering a part of the resin portion is formed on one of the first substrate and the second substrate. The present invention is also applicable to MEMS devices. For example, a MEMS device in which either a first substrate or a second substrate is provided with a drive region and a piezoelectric element, and this piezoelectric element is applied to a sensor or the like that detects pressure change, vibration, or displacement of the drive region. The present invention can also be applied.

  DESCRIPTION OF SYMBOLS 1 ... Printer, 2 ... Recording medium, 3 ... Recording head, 4 ... Carriage, 5 ... Carriage moving mechanism, 6 ... Conveying mechanism, 7 ... Ink cartridge, 8 ... Timing belt, 9 ... Pulse motor, 10 ... Guide rod, 14 ... actuator unit, 15 ... flow path unit, 16 ... head case, 17 ... accommodating space, 18 ... liquid introduction path, 21 ... nozzle plate, 22 ... nozzle, 24 ... communication substrate, 25 ... common liquid chamber, 26 ... individual communication Passage, 27 ... nozzle communication passage, 29 ... pressure chamber forming substrate, 30 ... pressure chamber, 31 ... vibration plate, 32 ... piezoelectric element, 33 ... sealing plate, 34 ... drive IC, 35 ... drive region, 36 ... non-drive Area 37, bump electrode 38, resin portion 39, conductive film 40 wiring, 41 individual terminal 42 common terminal 43 photosensitive adhesive 44 sealing space 45 penetrating , 46 ... upper surface side wiring, 47 ... IC terminal, 48 ... adhesive, 49 ... through hole, 52 ... lower surface side protective film, 52 '... metal layer, 53 ... lower surface side metal film, 53' ... metal layer, 55 ... Upper surface side protective film, 56... Upper surface side metal film

Claims (3)

A first substrate having a resin portion protruding from one surface and a first electrode covering a part of the resin portion; and a second substrate having a second electrode on a surface facing the one surface A MEMS device comprising: a substrate, wherein the first substrate and the second substrate are joined so as to conduct the first electrode and the second electrode,
A resin part forming step of forming the resin part on the one surface of the first substrate;
An electrode layer film forming step of forming an electrode layer serving as the first electrode on the one surface including the region where the resin portion is formed;
An electrode layer etching step of etching the electrode layer to form the first electrode;
Including
The method of manufacturing a MEMS device, wherein the temperature of the first substrate in the electrode layer deposition step is equal to or higher than the highest temperature of the first substrate after the electrode layer deposition step. A first substrate having a resin portion protruding from one surface and a first electrode covering a part of the resin portion; and a second substrate having a second electrode on a surface facing the one surface A MEMS device comprising: a substrate, wherein the first substrate and the second substrate are joined so as to conduct the first electrode and the second electrode,
A resin part forming step of forming the resin part on the one surface of the first substrate;
An electrode layer film forming step of forming an electrode layer serving as the first electrode on the one surface including the region where the resin portion is formed;
An electrode layer etching step of etching the electrode layer to form the first electrode;
A substrate bonding step of bonding the first substrate and the second substrate via an adhesive so as to make the first electrode and the second electrode conductive;
Including
The MEMS device manufacturing method, wherein a temperature of the first substrate in the electrode layer forming step is higher than a temperature of the first substrate in the substrate bonding step. A method for manufacturing a liquid jet head having the structure of the MEMS device according to claim 1,
A manufacturing method of a liquid jet head, wherein the manufacturing method of the MEMS device according to claim 1 or 2 is performed.

Images