JP2007062034A - Wiring structure, device, manufacturing method for device, liquid droplet ejecting head, manufacturing method for liquid droplet ejecting head, and liquid droplet ejector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wiring structure whereby a space between a driver IC and a driving element with a step can be made conductive by a fine pitch and without causing disconnection, and to provide a device, a manufacturing method for the device, a liquid droplet ejecting head, a manufacturing method for the liquid droplet ejecting head, and a liquid droplet ejector. <P>SOLUTION: The wiring structure is provided by setting a second member 20 on a first member 10. A second conductive part 44 prepared at the second member 20 and a first conductive part 90 formed on the top face of the first member 10 are electrically connected with each other by wiring 34. The second member 20 is equipped with a step structure. The second conductive part 44 is formed at an upper step of the step structure. A penetrating conductive part 85 is formed at a lower step of the step structure which penetrates the lower step and becomes conductive to the first conductive part 90. The wiring 34 is led from the top face of the upper step to the top face of the lower step passing on a step surface which makes the upper step and the lower step continuous with each other, thereby connecting a space between the second conductive part 44 and the penetrating conductive part 85. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a wiring structure, a device, a device manufacturing method, a droplet discharge head, a droplet discharge head manufacturing method, and a droplet discharge apparatus.

A droplet discharge method (inkjet method) has been proposed for image formation and microdevice manufacturing. This droplet discharge method is a method of forming a desired wiring pattern on a substrate by discharging a functional liquid containing a material for forming wirings in a semiconductor device into droplets from a droplet discharge head.
In general, a droplet discharge head is provided on a flow path forming substrate having a pressure generating chamber communicating with a nozzle and a communicating portion that continues between the pressure generating chambers, and on one surface side of the flow path forming substrate. A driving element, and a sealing substrate that is bonded to the driving element side of the flow path forming substrate and includes a driver IC (semiconductor element) for driving the driving element. The driver IC is electrically connected by wiring. By the way, since the droplet discharge head has a structure in which a sealing substrate is laminated on a flow path forming substrate, the driving element provided on the flow path forming substrate and the sealing substrate are provided on the sealing substrate. A step is generated between the driver IC and the driver IC. Therefore, when connecting the connection terminal of the driver IC and the wiring portion connected to the driving element, it is necessary to perform wiring connection through a step.

  As an example of such a droplet discharge head, an opening is formed in the sealing substrate, a wiring portion connected to a driving element is exposed in the opening, a connection terminal of the driver IC above the step, and a step A device is known that is connected to a wiring portion of a driving element at a lower portion by wire bonding through the opening (for example, see Patent Documents 1 to 3).

By the way, in recent years, a droplet discharge method is also used when forming a fine pattern such as high-definition pixel formation or microdevice wiring formation. Therefore, a droplet discharge head is used to cope with such miniaturization. It is desired to form the distance (nozzle pitch) between the nozzles provided in as small as possible (narrow). In addition, since a plurality of the drive elements are formed corresponding to the nozzles, it is necessary to reduce the distance between the piezoelectric elements according to the nozzle pitch when the nozzle pitch is reduced. However, when the distance between the piezoelectric elements is reduced, it is difficult to connect each wiring connected to the plurality of piezoelectric elements and the driver IC by wire bonding, for example, adjacent wire bonding contacts and short-circuits. There is a fear.
JP 2000-127379 A JP 2000-135790 A JP 2000-296616 A

  Therefore, it is conceivable to route the wiring pattern instead of wire bonding. In this case, for example, the inner surface of the flow path forming substrate in which the opening is formed is an inclined surface, and the sealing substrate, the flow path forming substrate, A structure that smoothly connects the two can be considered. That is, by forming a wiring on the upper surface of the flow path forming substrate from the upper surface of the sealing substrate through the inclined surface, the upper driver IC and the lower drive element can be made to conduct well. it can. By the way, as shown in FIG. 10A, the sealing substrate 20 is usually mounted on the flow path forming substrate 10 via the adhesive layer 3.

However, even if the sealing substrate 20 is brought into close contact with the flow path forming substrate 10 via the adhesive layer 3, the adhesive layer 3 is drawn inward by contraction when the adhesive layer 3 is cured. As a result, a gap T that is not filled with the adhesive layer 3 as shown in FIG. 10A is formed on the outer peripheral side between the flow path forming substrate 10 and the sealing substrate 20.
Under such a state, when an attempt is made to form a wiring pattern that runs on the slope of the sealing substrate 20 and reaches the upper surface of the sealing substrate 20 and the upper surface of the flow path forming substrate 10, for example, As shown in FIG. 10B, the resist 45 for forming the wiring pattern enters the gap T. Therefore, even in the structure in which the inner surface of the flow path forming substrate described above is an inclined surface, the wiring pattern formed at the connection portion between the inclined surface of the sealing substrate 20 and the upper surface of the flow path forming substrate 10 is disconnected. There is a problem that needs to be improved.

  The present invention has been made in view of the above circumstances, and can provide a wiring structure, a device, a device manufacturing method, and a liquid droplet that can be conducted between a driver IC having a step and a driving element at a fine pitch without disconnection. It is an object of the present invention to provide a discharge head, a method of manufacturing a droplet discharge head, and a droplet discharge device.

  In the wiring structure of the present invention, the second member is provided on the first member, and the second conductive portion provided on the second member and the first conductive portion provided on the upper surface of the first member are provided. In the wiring structure that is electrically connected by wiring, the second member has a step structure, the second conductive portion is provided in the upper step portion of the step structure, and the lower step portion is provided in the lower step portion of the step structure. A penetrating conductive portion that penetrates the first conductive portion and is connected to the first conductive portion, and the wiring passes through a stepped surface that connects the upper stepped portion and the lower stepped portion to the lower stepped portion from the upper surface of the upper stepped portion. The second conductive portion is connected to the penetrating conductive portion.

According to the wiring structure of the present invention, the first conductive portion provided on the upper surface of the first member is provided with the through conductive portion that penetrates the lower step portion of the step structure provided in the second member. The first conductive part can be conducted through the conductive part. Therefore, the wiring that connects between the through conductive portion and the second conductive portion is excellently connected between the first conductive portion and the second conductive portion through the through conductive portion.
In addition, since the upper step portion and the lower step portion are continuously connected by the step surface, for example, when a wiring pattern is formed by a sputtering method, as described above, between the first member and the second member. By entering the gap, patterning failure occurs and the wiring does not break.
Therefore, since the wiring is routed from the upper surface of the upper step part to the upper surface of the lower step part through the step surface, a short circuit between adjacent wirings can be prevented as compared with the case of using wire bonding. In addition, the wiring can be formed with a fine pitch.

In the wiring structure, it is preferable that the step surface is formed to be inclined with respect to the upper surface of the lower step portion, and the inclination angle is an acute angle.
In this way, the wiring is prevented from being bent suddenly by the step between the upper and lower steps. Therefore, the penetration conductive part and the second conductive part can be satisfactorily connected by the wiring formed along the acute angle inclined surface.

  A device according to the present invention includes the above wiring structure, wherein the second conductive portion is a connection terminal of a semiconductor element.

  According to the device of the present invention, since the second conductive portion serves as the connection terminal of the semiconductor element, the first conductive portion and the connection terminal of the semiconductor element are reliably connected via the through conductive portion as described above. Will be. Therefore, the yield at the time of mounting a semiconductor element can be improved, and the device becomes highly reliable.

Further, in the device, the through conductive portion is a metal material selected from the group consisting of Ni—Cr, Cu, Ni, Au, Ag, an alloy of a metal material selected from the group, a brazing material, or a conductive resin. It is preferable that it is comprised with either of the materials.
By using the through-conductive portion made of such a material, the first conductive portion and the connection terminal of the semiconductor element are electrically connected through the through-conductive portion, so that the semiconductor element operates well and is reliable. It becomes a highly functional device.

Further, in the device, the wiring includes a base pattern made of a photosensitive resin containing a catalyst that promotes deposition of plating, and Al, Ni-Cr, Cu, Ni, Au, or Ag deposited on the base pattern. It is preferable that the conductive material is included.
If it does in this way, a ground pattern of desired shape can be formed by patterning photosensitive resin, for example using a photolithographic method. Here, since the base pattern contains a catalyst that promotes the deposition of plating, by thickening the plating on the base pattern, a device having a highly reliable wiring with reduced electric resistance is obtained.

Alternatively, the wiring is composed of a conductive base pattern formed by a physical vapor phase method and a conductive material containing Al, Ni-Cr, Cu, Ni, Au, or Ag deposited on the base pattern. It is preferable.
In this way, by patterning the metal film by a sputtering method, for example, as a physical vapor phase method, a base pattern having conductivity is formed. Further, by plating, for example, on the base pattern, a device having highly reliable wiring with reduced electrical resistance is obtained.

  In the device, the connection terminal of the semiconductor element is formed of a metal material selected from the group consisting of Al, Ni-Cr, Cu, Ni, Au, and Ag, or an alloy of a metal material selected from the group. It is preferable.

  According to this configuration, when the wiring is formed by depositing the plating on the base pattern, the connection terminal of the semiconductor element is configured to include the metal material constituting the plating. The plated plating is bonded to the connection terminal, and the connection reliability between the wiring and the connection terminal is high.

In the device, it is preferable that the semiconductor element is held on an upper surface of the second member via an adhesive layer.
If it does in this way, it will become possible to mount a semiconductor element on the 2nd member easily and cheaply.

  In the device manufacturing method of the present invention, the second member is provided on the first member, and the gap between the semiconductor element provided on the second member and the first conductive portion provided on the upper surface of the first member is provided. In the method of manufacturing a device connected by wiring, a step of forming a step structure by etching a precursor substrate serving as a precursor of the second member and forming the second member by providing a through hole in a lower step portion of the step structure And aligning a part of the first conductive portion in the through hole and providing the second member on the first member, and embedding a conductive material in the through hole. The step of forming a through-conductive portion in the lower step portion, the step of providing a semiconductor element in the upper step portion, and the routing of the upper step portion and the lower step portion through a step surface that continues the connection, the connection of the semiconductor element Wiring to connect between the terminal and the through-conductor A step of forming, characterized by comprising a.

According to the device manufacturing method of the present invention, a part of the first conductive portion is disposed in a through hole provided in a lower step portion of the step structure, and the through conductive portion is embedded by filling the through hole with a conductive material. Since it is formed, the upper surface side of the lower step portion can be electrically connected to the first conductive portion through the through conductive portion. Therefore, the wiring that connects between the through conductive portion and the second conductive portion is excellently connected between the first conductive portion and the second conductive portion through the through conductive portion.
Further, when, for example, a sputtering method is used when forming the wiring pattern, according to this configuration, the upper and lower steps of the step structure formed by etching the precursor substrate are continuously formed by the step surface. Therefore, the disconnection of the wiring due to the gap generated between the first member and the second member as described above is prevented.
In addition, since this wiring is routed from the upper surface of the upper step portion to the upper surface of the lower step portion through the step surface, short-circuiting between adjacent wires is less likely to occur than when wire bonding is used. As a result, it is possible to provide a device that can be formed with a fine pitch and in which semiconductor elements are mounted at a high density.

In the device manufacturing method, the precursor substrate is preferably composed of a silicon substrate having a plane orientation (1, 0, 0), and the step structure is formed by anisotropically etching the silicon substrate. .
Here, by performing wet etching with an alkaline solution such as KOH as anisotropic etching on a silicon substrate having a plane orientation (1, 0, 0), the difference in etching rate of each plane orientation is caused. The side surface of the upper stage portion can be an inclined surface.

In the device manufacturing method, the wiring is formed with a base pattern made of a photosensitive resin containing a catalyst that promotes the deposition of plating, and then Al, Ni-Cr, Cu, Ni, Au are formed on the base pattern. Or a conductive material containing Ag is preferably deposited.
If it does in this way, a ground pattern of desired shape can be formed by patterning photosensitive resin, for example using a photolithographic method. Here, since the base pattern includes a catalyst that promotes the deposition of plating, the plating is thickened on the base pattern, thereby providing a highly reliable wiring with reduced electric resistance.

In the device manufacturing method, the connection terminal of the semiconductor element is a metal material selected from the group consisting of Al, Ni—Cr, Cu, Ni, Au, and Ag, or an alloy of a metal material selected from the group. It is preferable that it is formed by.
According to this configuration, when the wiring is formed by depositing the plating on the base pattern, the connection terminal of the semiconductor element is configured to include the metal material constituting the plating. The plated plating is bonded to the connection terminal, and the connection reliability between the wiring and the connection terminal is high.

  The droplet discharge head of the present invention includes a flow path forming substrate provided with a pressure generation chamber communicating with a nozzle for discharging droplets, and a pressure formed in the pressure generation chamber disposed on the upper surface side of the flow path formation substrate. A driving element that causes a change, a sealing substrate provided to cover the driving element provided on the flow path forming substrate, and a semiconductor element disposed on an upper surface side of the sealing substrate and driving the driving element; , The sealing substrate has a step structure, the semiconductor element is provided on the upper step portion of the step structure, and the lower step portion penetrates the lower step portion of the step structure. A through-conductive portion that is electrically connected to the wiring portion of the driving element is provided, and is routed from the upper surface of the upper step portion to the upper surface of the lower step portion through a step surface that connects the upper step portion and the lower step portion. The penetrating conductive portion and the semiconductor element by the formed wiring. Wherein the between the connection terminals are connected.

According to the droplet discharge head of the present invention, the through-conductive portion is provided which is electrically connected to the wiring portion of the driving element provided on the upper surface of the flow path forming substrate and penetrates the lower step portion of the step structure of the sealing substrate. The drive element can be conducted through the through-conductive portion. Therefore, the wiring that connects between the through conductive portion and the connection terminal of the semiconductor element provides good conduction between the drive element and the connection terminal of the semiconductor element through the through conductive portion.
For example, when a wiring pattern is formed by sputtering, according to the present configuration, the upper step portion and the lower step portion are continuously connected by the step surface, so that the flow path forming substrate and the sealing substrate are used as described above. It is possible to prevent the wiring from being disconnected by the gap between the two.
In addition, compared to the case where the wire is routed from the upper surface of the upper step portion to the upper surface of the lower step portion through the step surface and wire bonding is used, a short circuit between adjacent wires is prevented and wiring is performed at a fine pitch. Can be formed.

  The method for manufacturing a droplet discharge head according to the present invention includes a flow path forming substrate provided with a pressure generating chamber communicating with a nozzle for discharging droplets, and the pressure generating chamber disposed on the upper surface side of the flow path forming substrate. A driving element for causing a pressure change in the chamber; a sealing substrate provided to cover the driving element provided on the flow path forming substrate; and the driving element disposed on an upper surface side of the sealing substrate to drive the driving element. A droplet discharge head including a semiconductor element, wherein a stepped structure is formed by etching a silicon substrate serving as a precursor of the sealing substrate, and a through hole is provided in a lower step portion of the stepped structure. A step of forming the sealing substrate, a step of positioning the wiring portion connected to the driving element in the through hole, and providing the sealing substrate on the flow path forming substrate; By embedding a conductive material in the through hole, A step of forming a penetrating conductive portion in the lower step portion, a step of providing a semiconductor element on the upper step portion, and a routing step that passes through the step surface that connects the upper step portion and the lower step portion. Forming a wiring for connecting between the connection terminal and the through-conductive portion.

According to the method for manufacturing a droplet discharge head of the present invention, the wiring portion of the driving element is disposed in the through hole provided in the lower step portion of the step structure, and the through hole is embedded with a conductive material, thereby passing through the conductive layer. Since the portion is formed, the upper surface side of the lower step portion can be electrically connected to the driving element through the through conductive portion. Therefore, the wiring connects between the through-conductive portion and the connection terminal of the semiconductor element, and well conducts between the driving element and the semiconductor element via the through-conductive portion.
Further, when the wiring is formed, for example, when a sputtering method is employed, according to this configuration, the upper and lower steps of the step structure formed by etching the precursor substrate are continuously formed by the step surface. Therefore, the disconnection of the wiring due to the gap between the first member and the second member as described above can be prevented.
In addition, since this wiring is routed from the upper surface of the upper step portion to the upper surface of the lower step portion through the step surface, short-circuiting between adjacent wires is less likely to occur than when wire bonding is used. Thus, the droplet discharge head can be formed with a fine pitch and the semiconductor elements are mounted at a high density.

  A droplet discharge apparatus according to the present invention includes the droplet discharge head described above.

  According to the droplet discharge device of the present invention, as described above, since it includes the droplet discharge head in which the connection terminal to the semiconductor element and each drive element are securely connected by the fine pitch wiring, A droplet discharge device provided with this is highly reliable and small.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
In the following description, an XYZ orthogonal coordinate system is set, and the positional relationship of each member will be described with reference to this XYZ orthogonal coordinate system. A predetermined direction in the horizontal plane is defined as the X-axis direction, a direction orthogonal to the X-axis direction in the horizontal plane is defined as the Y-axis direction, and a direction orthogonal to the X-axis direction and the Y-axis direction (that is, the vertical direction) is defined as the Z-axis direction.

(Droplet ejection head)
First, a first embodiment of a droplet discharge head according to the present invention will be described with reference to FIGS.
1 is a perspective configuration diagram showing an embodiment of a droplet discharge head, FIG. 2 is a partially cutaway perspective view of the droplet discharge head viewed from below, and FIG. 3 is taken along line AA in FIG. FIG.
The droplet discharge head 1 of the present embodiment discharges a functional liquid in the form of droplets from a nozzle. As shown in FIG. 3, the droplet discharge head 1 is disposed on a flow path forming substrate 10 in which a pressure generation chamber 12 communicating with a nozzle 15 from which droplets are discharged is formed, and on the upper surface of the pressure generation chamber 12. The piezoelectric element (driving element) 300 that causes a pressure change in the pressure generating chamber 12, the reservoir forming substrate (sealing substrate) 20 that is disposed on the upper surface of the pressure generating chamber 12 and covers the piezoelectric element 300, and the reservoir forming substrate 20 And a semiconductor element 200 that drives the piezoelectric element 300. In addition, the connection terminal 44 of the semiconductor element 200 and the lead electrode (wiring portion) 90 that is electrically connected to the piezoelectric element 300 are electrically connected by the wiring 34.
The operation of the droplet discharge head 1 is controlled by an external controller (not shown) connected to the semiconductor element 200.

  Here, the droplet discharge head 1 is provided with the first member as the flow path forming substrate 10 and the second member as the reservoir forming substrate 20 in the device and the wiring structure of the present invention. Furthermore, a terminal portion that conducts to the piezoelectric element 300 is used as a first conductive portion, and a connection terminal of the semiconductor element 200 is provided as a second conductive portion. Therefore, the droplet discharge head 1 according to the present embodiment includes one embodiment of the device and one embodiment of the wiring structure. It also includes descriptions of structures and device embodiments.

(nozzle)
As shown in FIG. 2, a nozzle substrate 16 is mounted on the lower side (−Z side) of the droplet discharge head 1. The nozzle substrate 16 is provided with a plurality of nozzles 15 for discharging droplets arranged in the Y-axis direction. In the present embodiment, a group of nozzles 15 arranged in a plurality of regions on the nozzle substrate 16 are referred to as a first nozzle group 15A, a second nozzle group 15B, a third nozzle group 15C, and a fourth nozzle group 15D, respectively. .

The first nozzle group 15A and the second nozzle group 15B are arranged side by side in the X-axis direction. The third nozzle group 15C is provided on the + Y side of the first nozzle group 15A, and the fourth nozzle group 15D is provided on the + Y side of the second nozzle group 15B. The third nozzle group 15C and the fourth nozzle group 15D are arranged side by side in the X-axis direction.
In FIG. 2, each of the nozzle groups 15 </ b> A to 15 </ b> D is illustrated as being configured by six nozzles 15, but each nozzle group is actually configured by, for example, about 720 nozzles 15. Is.

(Pressure generation chamber)
A flow path forming substrate (first member) 10 is disposed on the upper side (+ Z side) of the nozzle substrate 16. The lower surface of the flow path forming substrate 10 and the nozzle substrate 16 are fixed via, for example, an adhesive or a heat welding film. The flow path forming substrate 10 can be made of silicon, glass, a ceramic material, or the like, and is formed of silicon in this embodiment. A plurality of partition walls 11 extending in the X direction from the center portion are formed inside the flow path forming substrate 10. The partition wall 11 is formed by partially removing the silicon single crystal substrate which is a base material of the flow path forming substrate 10 by anisotropic etching. With the partition wall 11, a plurality of substantially comb-shaped opening regions in a plan view are defined in the flow path forming substrate 10. Of these opening regions, a portion formed extending in the X-axis direction is surrounded by the nozzle substrate 16 and the vibration plate 400 to form the pressure generation chamber (first member) 12. The pressure generation chamber 12 stores the functional liquid and discharges the functional liquid from the nozzle 15 by the pressure applied when the droplet discharge head 1 is operated.

  Each pressure generating chamber 12 is provided corresponding to a plurality of nozzles 15. That is, a plurality of pressure generation chambers 12 are provided side by side in the Y-axis direction so as to correspond to the plurality of nozzles 15 constituting each of the first to fourth nozzle groups 15A to 15D. The plurality of pressure generating chambers 12 formed corresponding to the first nozzle group 15A constitutes the first pressure generating chamber group 12A, and the plurality of pressure generating chambers 12 formed corresponding to the second nozzle group 15B are the first. Two pressure generation chamber groups 12B are formed, and a plurality of pressure generation chambers 12 formed corresponding to the third nozzle group 15C constitute a third pressure generation chamber group 12C, and a plurality of pressure generation chambers 12B are formed corresponding to the fourth nozzle group 15D. The generated pressure generation chamber 12 constitutes a fourth pressure generation chamber group 12D. The first pressure generation chamber group 12A and the second pressure generation chamber group 12B are arranged side by side in the X-axis direction, and a partition wall 10K extending in the Y-axis direction is formed between them. Similarly, the third pressure generation chamber group 12C and the fourth pressure generation chamber group 12D are arranged side by side in the X-axis direction, and a partition wall 10K extending in the Y-axis direction is formed between them.

(Reservoir)
In addition, a portion extending in the Y direction in the drawing in the planar comb-shaped opening region formed in the flow path forming substrate 10 constitutes the reservoir 100. Ends on the substrate outer edge side (+ X side) in the plurality of pressure generation chambers 12 forming the first pressure generation chamber group 12A are connected to the reservoir 100 described above. The reservoir 100 preliminarily holds the functional liquid supplied to the pressure generation chamber 12, and is a common functional liquid holding chamber (ink chamber) of the plurality of pressure generation chambers 12 constituting the first pressure generation chamber group 12A. ). A reservoir 100 similar to that described above is also connected to each of the second, third, and fourth pressure generation chamber groups 12B, 12C, and 12D, and the functional fluid supplied to the pressure generation chamber groups 12B to 12D, respectively. The temporary storage part is comprised.

  As shown in FIG. 3, the reservoir 100 includes a reservoir portion 21 formed on the reservoir forming substrate 20 and a communication portion 13 formed on the flow path forming substrate 10. The communication portion 13 has a function of connecting the reservoir portion 21 to each of the pressure generation chambers 12. A compliance substrate 30 having a structure in which a sealing film 31 and a fixing plate 32 are laminated is bonded to the outside of the reservoir forming substrate 20 (on the side opposite to the flow path forming substrate 10). In the compliance substrate 30, the sealing film 31 disposed on the inside is made of a material having low rigidity and flexibility (for example, a polyphenylene sulfide film having a thickness of about 6 μm). On the other hand, the fixing plate 32 disposed on the outside is made of a hard material such as metal (for example, stainless steel having a thickness of about 30 μm). The fixing plate 32 has an opening 33 formed by cutting out a planar region corresponding to the reservoir 100. With this configuration, the upper portion of the reservoir 100 is sealed only with a flexible sealing film 31 and is a flexible portion 22 that can be deformed by a change in internal pressure. Further, the compliance substrate 30 is formed with a functional liquid introduction port 25 for supplying a functional liquid to the reservoir 100, and the reservoir forming substrate 20 is introduced to communicate the functional liquid introduction port 25 with the reservoir 100. A path 26 is provided.

The functional liquid introduced from the functional liquid introduction port 25 flows into the reservoir 100 via the introduction path 26, and is further supplied to each of the plurality of pressure generation chambers 12 constituting the first pressure generation chamber group 12A via the supply path 14. It has become so. Note that a pressure change may occur inside the reservoir 100 due to the flow of the functional liquid or the ambient heat when the piezoelectric element 300 is driven.
However, since the flexible portion 22 of the reservoir 100 is bent and deformed to absorb the pressure change, the inside of the reservoir 100 can always be maintained at a constant pressure.

(Piezoelectric element)
On the other hand, a diaphragm 400 is disposed on the upper surface side (+ Z side) of the flow path forming substrate 10 in the figure. The diaphragm 400 has a structure in which an elastic film 50 and a lower electrode film 60 are laminated in order from the flow path forming substrate 10 side. The elastic film 50 disposed on the flow path forming substrate 10 side is made of a silicon oxide film having a thickness of about 1 to 2 μm, for example, and the lower electrode film 60 is a metal film having a thickness of about 0.2 μm, for example. It consists of In the present embodiment, the lower electrode film 60 functions as a common electrode for a plurality of piezoelectric elements 300 disposed between the flow path forming substrate 10 and the reservoir forming substrate 20.

A piezoelectric element 300 for deforming the diaphragm 400 is disposed on the upper surface side (+ Z side) of the diaphragm 400 in the figure. The piezoelectric element 300 has a structure in which a piezoelectric film 70 and an upper electrode film 80 are laminated in order from the lower electrode film 60 side. The piezoelectric film 70 is made of, for example, a PZT film having a thickness of about 1 μm, and the upper electrode film 80 is made of, for example, a metal film having a thickness of about 0.1 μm.
The concept of the piezoelectric element 300 may include the lower electrode film 60 in addition to the piezoelectric film 70 and the upper electrode film 80. This is because the lower electrode film 60 functions as the piezoelectric element 300 and also functions as the diaphragm 400. In the present embodiment, a configuration in which the elastic film 50 and the lower electrode film 60 function as the diaphragm 400 is employed, but the elastic film 50 may be omitted and the lower electrode film 60 may also serve as the elastic film 50. it can.

In such a piezoelectric element 300, a lead electrode (first conductive portion) 90 made of, for example, gold (Au) or the like for connection to the semiconductor element 200 is formed as a lead-out wiring. Therefore, the lead electrode 90 is included in a part of the piezoelectric element.
In other words, each lead electrode 90 extends from the vicinity of the end of each pressure generating chamber 12 of the upper electrode film 80 on the side of the row to the elastic film 50. Although details will be described later, each lead electrode 90 extends to a through conductive portion provided in the reservoir forming substrate 20. In the vicinity of the end of the lead electrode 90, the semiconductor element 200 and the piezoelectric element 300 can be conducted through the wiring 34 connected to the through conductive portion.

  A plurality of the piezoelectric elements 300 are provided so as to correspond to the plurality of nozzles 15 and the pressure generating chambers 12. In the present embodiment, for convenience, a group of piezoelectric elements 300 provided in a line in the Y-axis direction so as to correspond to each of the nozzles 15 constituting the first nozzle group 15A is referred to as a first piezoelectric element group, A group of piezoelectric elements 300 provided in a line in the Y-axis direction so as to correspond to each of the nozzles 15 constituting the second nozzle group 15B is referred to as a second piezoelectric element group. A group of piezoelectric elements corresponding to the third nozzle arm is referred to as a third piezoelectric element group, and a group of piezoelectric elements corresponding to the fourth nozzle arm is referred to as a fourth piezoelectric element group. The first piezoelectric element group and the second piezoelectric element group are arranged side by side in the X axis direction, and similarly, the third piezoelectric element group and the fourth piezoelectric element group are arranged side by side in the X axis direction. The droplet discharge head 1 includes four semiconductor elements 200A to 200D in order to drive the first to fourth piezoelectric element groups.

(Reservoir forming substrate)
A reservoir forming substrate (sealing substrate, second member) 20 is disposed on the upper surface side (+ Z side) of the flow path forming substrate 10 so as to cover the piezoelectric element 300. The flow path forming substrate 10 and the reservoir forming substrate 20 are bonded together by an adhesive layer (not shown) made of an adhesive resin or the like. Since the reservoir forming substrate 20 is a member that forms the base of the droplet discharge head 1 together with the flow path forming substrate 10, a rigid material having substantially the same thermal expansion coefficient as that of the flow path forming substrate 10 is used as its constituent material. Is preferred. In the case of this embodiment, since the flow path forming substrate 10 is made of silicon, a silicon single crystal substrate made of the same material as that is preferably used. Since the silicon substrate can be easily processed with high accuracy by anisotropic etching, there is an advantage that a piezoelectric element holding portion 24 and the like described later can be easily formed.
As with the flow path forming substrate 10, the reservoir forming substrate 20 can be configured using glass, ceramic material, or the like.

  The reservoir forming substrate 20 is provided with a sealing portion 23 that hermetically seals the piezoelectric element 300. In the case of the present embodiment, a portion sealing the first piezoelectric element group is referred to as a first sealing portion 23A, and a portion sealing the second piezoelectric element group is referred to as a second sealing portion 23B. To. Similarly, a portion sealing the third piezoelectric element group is referred to as a third sealing portion, and a portion sealing the fourth piezoelectric element group is referred to as a fourth sealing portion.

  In addition, the sealing portion 23 is provided with a piezoelectric element holding portion 24 formed of a concave portion having a substantially rectangular shape in plan view extending in the direction perpendicular to the paper surface of FIG. The piezoelectric element holding portion 24 has a function of securing a space around the piezoelectric element 300 that does not hinder the movement of the piezoelectric element 300 and sealing the space. The piezoelectric element holding portion 24 has a dimension capable of sealing at least the piezoelectric film 70 of the piezoelectric element 300. The piezoelectric element holding unit 24 may be partitioned for each of the plurality of piezoelectric elements 300.

  Thus, the reservoir forming substrate 20 has a function as a sealing substrate that blocks the piezoelectric element 300 from the external environment. By sealing the piezoelectric element 300 with the reservoir forming substrate 20, it is possible to prevent deterioration of the characteristics of the piezoelectric element 300 due to external moisture or the like. Further, in the present embodiment, the inside of the piezoelectric element holding part 24 is only sealed, but the inside of the piezoelectric element holding part 24 is made to be in a vacuum or an atmosphere such as nitrogen or argon. It can be kept at low humidity. With these configurations, deterioration of the piezoelectric element 300 can be more effectively prevented.

(Wiring structure and device)
Here, an embodiment of the wiring structure and device of the present invention included in a part of the droplet discharge head 1 will be described in detail with reference to FIG.
FIG. 4 is a diagram showing a device that constitutes a part of the droplet discharge head 1, and is an enlarged view of the area A in FIG. 4, where reference numeral 500 denotes the device. In FIG. 4, the illustration of the piezoelectric element 300 and the piezoelectric element holding portion 24 is omitted to simplify the illustration.

The device 500 includes a wiring structure 500a. Here, the step structure provided on the reservoir forming substrate 20 will be described.
As shown in FIG. 1, a recess 20a is provided between the first sealing portion 23A and the second sealing portion 23B, that is, the reservoir forming substrate 20 (see FIG. 1). Therefore, the reservoir forming substrate 20 has a step structure in which the surface on which the recess 20a is not formed is an upper surface and the bottom of the recess 20a is a lower surface.
Specifically, the semiconductor element 200 is provided in the upper step portion of the step structure, and a through conductive portion 85 that passes through the lower step portion and is connected to the piezoelectric element 300 is provided in the lower step portion of the step structure. Is provided. Here, the upper step portion in the step structure refers to a reservoir-forming substrate portion having a relatively thick film thickness where the recess portion 20a is not formed, and the lower step portion in the step structure includes the recess portion 20a. Thus, the reservoir forming substrate portion having a relatively thin film thickness is shown. The semiconductor element 200 includes, for example, a semiconductor integrated circuit (IC) including a circuit board or a drive circuit.

  The semiconductor element 200 is mounted on the reservoir forming substrate 20 in a face-down state with the connection terminal surface facing downward. An adhesive 42 made of a thermoplastic material such as polyimide is disposed at the central portion of the semiconductor element 200. By applying pressure to the reservoir forming substrate 20 while heating the semiconductor element 200, the semiconductor element 200 is stored in the reservoir. It is fixed to the upper surface of the formation substrate 20. By mounting with the adhesive 42 as described above, the semiconductor device 200 can be easily and inexpensively mounted, and the low-cost droplet discharge head 1 is obtained.

The wiring structure 500a in the present embodiment is drawn from the upper surface of the upper step portion to the upper surface of the lower step portion through a step surface that connects the upper step portion and the lower step portion of the step structure provided on the reservoir forming substrate 20. A wiring 34 to be rotated is provided. The wiring 34 connects between the semiconductor element 200 including the second conductive portion provided in the upper step portion of the step structure and the through conductive portion 85 provided in the lower step portion of the step structure.
That is, since the semiconductor element 200 is mounted on the upper portion of the reservoir forming substrate 20 in the droplet discharge head 1, the device 500 having the second conductive portion in the wiring structure 500a as the connection terminal 44 of the semiconductor element 200 is provided. And includes an embodiment of the device and wiring structure.

By the way, the step surface which makes the said upper step part and the said lower step part continue is the inclined surface 35 with respect to the upper surface of the lower step part of the said step structure, The inclination angle is an acute angle.
As will be described later, the inclined surface 35 uses the difference in etching rate of each surface orientation when wet etching is performed with an alkaline solution such as KOH on a silicon substrate having a surface orientation (1, 0, 0). The inclination angle is about 54 °.

  Further, the through conductive portion 85 is formed in the through hole 36 provided in the lower step portion by a metal material selected from the group consisting of Ni-Cr, Cu, Ni, Au, Ag, an alloy of a metal material selected from the group, A brazing material or a conductive resin material is embedded. In the present embodiment, as will be described later, Ni plating (brazing material) is embedded in the through hole 36 and the surface thereof is covered with Au plating. The penetrating conductive portion 85 is provided on the lead electrode 90 whose upper surface is exposed on the upper surface side of the lower step portion of the reservoir forming substrate 20 and whose lower surface side is electrically connected to the piezoelectric element 300. By the through conductive portion 85 made of such a material, the upper surface side (side on which the semiconductor element is provided) and the lower surface side (side on which the drive element is provided) in the lower step portion can be conducted. Specifically, a part of the piezoelectric element 300 (lead electrode 90) provided on the upper surface of the flow path forming substrate 10 which is the lower layer of the reservoir forming substrate 20 can be conducted through the through conductive portion 85. Yes.

Here, the penetrating conductive portion is formed by a wiring 34 that runs from an upper surface of the upper step portion to an upper surface of the lower step portion through an inclined surface (step surface) 35 that connects the upper step portion and the lower step portion. 85 and the connection terminal 44 of the semiconductor element 200 are connected. By routing the wiring 34 on the inclined surface 35, the wiring 34 is prevented from being bent suddenly due to the step formed by the upper and lower steps of the reservoir forming substrate 20.
That is, from the upper step portion of the step structure (upper portion of the sealing portion 23) to the through conductive portion 85 provided on the lower step portion (lower step portion of the sealing portion 23) through the inclined surface (step surface) 35. The wiring 34 is routed.

  The wiring 34 can be electrically connected to the lead electrode 90 connected to the piezoelectric element 300 through the through conductive portion 85. Therefore, the wiring 34 connecting the through conductive portion 85 and the connection terminal 44 of the semiconductor element 200 is connected between the piezoelectric element 300 and the connection terminal 44 of the semiconductor element 200 through the through conductive portion 85. Have good continuity.

The wiring 34 has a base pattern 34a made of a photosensitive resin containing a catalyst that promotes the deposition of plating, and a conductive material containing Al, Ni-Cr, Cu, Ni, Au, or Ag deposited on the base pattern 34a. It is composed of materials. Specifically, by using a photosensitive resin material in which fine particles of Pd (palladium) are dispersed as the base pattern 34a, the resin material can be patterned into a desired shape by exposure and development. And the manufacturing process can be simplified. And in the base pattern 34a comprised with the resin material to which the catalyst was provided, the plating 34b is deposited with respect to the catalyst. These platings 34b are made of a metal material such as Cu, Ni, or Au. In addition, plating of a different material may be deposited on the surface of each wiring and connection terminal.
Further, since the base pattern 34a contains a catalyst that promotes the deposition of plating, a conductive material having a film thickness is plated 34b on the base pattern 34a, thereby providing a resistance value necessary for wiring.

  In addition, a plurality of connection terminals 44 are provided on the periphery of the lower surface side (side on which the adhesive 42 is provided) of the semiconductor element 200. The connection terminal 44 is made of a conductive material containing Al, Ni—Cr, Cu, Ni, Au, or Ag, or a metal material in which two or more of these are combined. Therefore, when a conductive material is plated on the base pattern 34a and the wiring 34 is formed as described later, by combining the plating 34b deposited from the base pattern 34a and the plating deposited from the connection terminal 44, The semiconductor element 200 and the lead electrode 90 are reliably connected.

  FIG. 5 is an enlarged explanatory view of a plating joint portion between the wiring 34 and the connection terminal 44 of the semiconductor element 200 described above. As shown in FIG. 5, a plating 44a is deposited on the surface of the connection terminal 44 of the semiconductor element 200, and a plating 34b is deposited on the base pattern 34a. The base pattern 34 a is formed on the lead electrode 90 connected to the piezoelectric element 300. Therefore, the plating 44a and the plating 34b grown in this manner are coupled, whereby the connection terminal 44 and the wiring 34 are electrically connected. That is, by using the wiring structure of the present invention by the wiring 34, the droplet discharge head 1 as a device on which the semiconductor element 200 is mounted is configured.

By the way, the flow path forming substrate 10 and the reservoir forming substrate 20 are bonded to each other through the adhesive layer 3. Specifically, as shown in FIG. 4, the adhesive layer 3 is provided on the reservoir forming substrate 20 side. Therefore, the adhesive layer 3 is disposed between the lead electrode 90 and the reservoir forming substrate 20. Thus, the two substrates 10 and 20 are bonded together.
Here, as described with reference to FIG. 10, for example, the adhesive layer 3 contracts when the adhesive layer 3 is cured, whereby the adhesive layer 3 is drawn inward, and as a result, the flow path forming substrate 10 and the reservoir On the outer peripheral side with respect to the formation substrate 20, a void portion T that is not filled with the adhesive layer 3 is formed. However, in the droplet discharge head 1 according to the present embodiment, as described above, the reservoir forming substrate 20 has a step structure, and the wiring 34 is provided along the inclined surface 35 between the upper and lower steps of the step structure. Forming.
According to this configuration, since the upper step and the lower step are continuously connected by the inclined surface 35, the wiring 34 is not disconnected due to the patterning failure due to the gap, and therefore the wiring 34 is connected to the piezoelectric element 300. The conducting lead electrode 90 and the connection terminal 44 of the semiconductor element 200 are conducting well.

(Operation of droplet discharge head)
In order to eject liquid droplets of the functional liquid by the liquid droplet ejection head 1 shown in FIG. 3, an external controller (not shown) connected to the liquid droplet ejection head 1 is connected to the functional liquid inlet 25 (not shown). The external functional liquid supply device is driven. The functional liquid delivered from the external functional liquid supply device fills the internal flow path of the droplet discharge head 1 up to the nozzle 15 after being supplied to the reservoir 100 via the functional liquid introduction port 25.

Then, the external controller transmits drive power and a command signal to the semiconductor element 200 mounted on the reservoir forming substrate 20. The semiconductor element 200 that receives the command signal or the like transmits a drive signal based on the command from the external controller to each piezoelectric element 300.
Then, as a result of applying a voltage between the lower electrode film 60 and the upper electrode film 80 corresponding to the pressure generating chamber 12, the elastic film 50, the lower electrode film 60, and the piezoelectric film 70 are displaced. Due to the displacement, the volume of each pressure generating chamber 12 changes, the internal pressure increases, and the droplets are ejected from the nozzle 15.

According to the droplet discharge head 1 having such a configuration, the lead electrode 90 connected to the piezoelectric element 300 provided on the upper surface of the flow path forming substrate 10 penetrates the lower step portion of the step structure provided in the reservoir forming substrate 20. Since the through conductive portion 85 is provided, the piezoelectric element 300 can be conducted through the through conductive portion 85. Therefore, the wiring that connects between the through-conductive portion and the connection terminal of the semiconductor element conducts favorably between the drive element and the connection terminal of the semiconductor element via the through-conductive portion 85.
In addition, as described above, in this configuration, the base pattern 34a of the wiring is formed by, for example, the sputtering method along the step surface in which the upper step portion and the lower step portion are continuously connected by the inclined surface 35. Since the wiring 34 is formed by depositing the plating on the base plate 34a, the patterning of the base pattern 34a may be caused by the gap T between the flow path forming substrate 10 and the reservoir forming substrate 20 as described above. Therefore, the wiring 34 formed by depositing the plating 34b on the base pattern 34a is prevented from being disconnected.

In addition, according to the droplet discharge head 1 of the present embodiment, it is not necessary to provide a space for drawing a wire, as compared with the conventional case where the semiconductor element 200 is mounted using wire bonding. For this reason, even when the wiring 34 is narrowed as the nozzle 15 is narrowed, the wiring 34 is routed along the inclined surface 35 so that a short circuit due to contact between adjacent wirings hardly occurs. Thus, the semiconductor element 200 can be reliably mounted while securing the general connection. In addition, it is possible to mount with a short TAT, a low cost, and a high yield as compared with the conventional mounting by wire bonding.
Moreover, since the opening region (etching region) in the reservoir forming substrate 20 can be reduced compared to the case where the through groove is formed in the flow path forming substrate 10 as in the case of wiring connection using the conventional wire bonding, for example, When the reservoir forming substrate 20 is adhered to the flow path forming substrate 10, cracking or the like when handling the reservoir forming substrate 20 can be prevented, and the handling of the reservoir forming substrate 20 is facilitated.

As described above, the droplet discharge head 1 includes the device 500 in which the semiconductor element 200 is mounted by the wiring structure 500a with high conduction reliability having the wiring 34 routed at a fine pitch without disconnection. Therefore, it is highly reliable and small.
According to the wiring structure 500a of the present embodiment, the first conductive portion (lead electrode 90) below the step and the second conductive portion (connection terminal 44) above the step can be reliably electrically connected. In addition to the droplet discharge head, other devices can be mounted via a step, and can be widely applied to electronic devices, printing devices, and the like.

(Method for manufacturing droplet discharge head)
Next, as an embodiment of the method for manufacturing a droplet discharge head according to the present invention, the case of manufacturing the droplet discharge head 1 will be described with reference to FIG. Since the droplet discharge head 1 includes the device itself of the present invention as described above, a method for manufacturing a device by the following steps for manufacturing a droplet discharge head will also be described. Moreover, each figure shown in FIG. 6 is a figure corresponding to the schematic cross-sectional structure which follows the AA line of FIG.

First, a step of forming a reservoir forming substrate 20 as a sealing substrate is performed.
As shown in FIG. 6A, anisotropic etching is performed on the center of the upper surface of the silicon single crystal substrate (precursor substrate) 120 having a plane orientation (1, 0, 0) as a precursor of the reservoir forming substrate. To form a recess 20a. Specifically, first, the surface of the silicon single crystal substrate 120 is thermally oxidized to form a silicon oxide film. Next, a resist is applied to the surface of the silicon single crystal substrate 120, and an opening corresponding to a portion where the recess 20a is to be formed is provided by photolithography.

Next, the opening of the resist is treated with hydrofluoric acid to form the opening in the silicon oxide film. Next, the silicon single crystal substrate 120 is immersed in an aqueous solution of about 35 wt% potassium hydroxide (KOH), and anisotropic etching of the silicon single crystal substrate 120 exposed from the opening of the silicon oxide film is performed. At this time, due to the difference in the etching rate of each plane orientation, the side surface of the recess 20a is formed on the silicon single crystal substrate 120 as an inclined surface 35 of about 54 °.
At this time, the recess 20a does not penetrate the silicon single crystal substrate 120, and the etching is finished in a state in which the silicon single crystal substrate 120 has a thickness of about 10 to 50 μm. Therefore, the silicon single crystal substrate 120 has a step structure in which a portion having a relatively thick thickness by the recess 20a is an upper step portion of the step structure and a portion having a relatively thin thickness by the recess is a lower step portion of the step structure. It will be prepared.

Subsequently, the through hole 36 is formed at a predetermined position of the lower step portion of the step structure by using anisotropic etching in the same manner as the concave portion 20a. Here, the predetermined position means that at least a lead electrode 90 that is electrically connected to the piezoelectric element 300 is disposed in the through-hole 36 in a bonding process between the reservoir forming substrate 20 and the flow path forming substrate 10 described later. It means a possible position. The through hole 36 has a rectangular shape in plan view and has an inclined surface due to the difference in etching rate of each surface orientation.
After the etching is completed, the surface of the silicon single crystal substrate 120 is again thermally oxidized to form a silicon oxide film (not shown). Similarly, the reservoir portion 21 and the piezoelectric element holding portion 24 are formed by etching. Therefore, as shown in FIG. 3, the stepped surface has a stepped structure, the stepped surface connecting the upper stepped portion and the lower stepped portion is an acute inclined surface 35, and a through hole 36 is formed in the lower stepped portion. A reservoir forming substrate 20 is formed.

Next, the reservoir forming substrate 20 is provided on the flow path forming substrate 10 by aligning the lead electrodes (wiring portions) 90 that are electrically connected to the piezoelectric elements 300 in the through holes 36.
Specifically, as shown in FIG. 6B, in a state where the position covering the piezoelectric element 300 on the flow path forming substrate 10 before the etching process and the position of the through hole 36 are matched, 10 and the reservoir forming substrate 20 are bonded to each other through the adhesive layer 3. At this time, a lead electrode 90 connected to the piezoelectric element 300 extending in the central portion on the flow path forming substrate 10 is formed in the central portion of the reservoir forming substrate 20 and is provided in the lower step portion of the step structure. It is disposed in the hole 36.
For example, after pre-treatment, the substrate is immersed in an electroless Ni plating solution, Ni plating is grown from the lead electrode 90 disposed in the through hole 36, and the through hole 36 is filled with Ni plating. To do. Thereafter, the Ni surface is coated by a substitution Au plating method. Note that the through conductive portion 85 is not limited to the above manufacturing method, and for example, a conductive resin may be embedded in the through hole 36 by a dispenser or the like.
Next, as shown in FIG. 6B, anisotropic etching is performed on the flow path forming substrate 10 made of a silicon single crystal substrate to produce the pressure generating chamber 12 and the like, and the reservoir forming substrate 20 is compliant. The substrate 30 is bonded, and the nozzle substrate 16 is bonded to the flow path forming substrate 10.

Next, a step of forming the wiring 34 is performed.
Specifically, as shown in FIG. 6 (c), the upper step portion passes through an inclined surface 35 that connects the upper step portion and the lower step portion of the step structure provided on the reservoir forming substrate 20 and A base pattern 34a is formed on the lower step. Specifically, first, a photosensitive resin containing a catalyst that promotes the deposition of plating, a liquid material of a photosensitive resin material in which fine particles of Pd (palladium) are dispersed, is sprayed on the surface of the reservoir forming substrate 20. By applying by a coating method or the like, the photosensitive resin can be evenly provided on the inclined surface 35.

Then, the resin material is exposed and developed through a mask on which the pattern of the wiring 34 is drawn. As a result, the base pattern 34 a for forming the wiring 34 is patterned on the surface of the silicon single crystal substrate 120. The base pattern 34a is preferably formed in a state where at least a part of the upper surface of the through conductive portion 85 is exposed, whereby the through conductive portion 85 and the semiconductor are formed by plating 34b deposited on the base pattern 34a. Conduction with the element 200 is possible.
At this time, since the upper step portion and the lower step portion of the step structure are continuously connected by the inclined surface (step surface) 35, the base pattern 34a has the inclined surface 35 between the upper step portion and the lower step portion. Connected smoothly along.
In forming the base pattern 34a, direct drawing may be performed by using a sputtering method through an Si mask or an inkjet method.

By the way, as described above, when the adhesive layer 3 bonding the reservoir forming substrate 20 and the flow path forming substrate 10 is cured, the adhesive layer 3 contracts and is pulled inward, and FIG. 10 is used. As described, a gap T that is not filled with the adhesive layer 3 is formed on the outer peripheral side between the flow path forming substrate 10 and the reservoir forming substrate 20.
In this configuration, by forming the recess 20 a in the reservoir forming substrate 20, a step structure in which the upper step portion and the lower step portion are continuously connected by the inclined surface 35 is provided. Therefore, unlike the conventional configuration (see FIG. 10), the flow path forming substrate 10 is not exposed in the lower step portion, and the base pattern 34a formed along the step structure is disconnected by the gap portion T. There is nothing.

Next, a step of providing the semiconductor element 200 on the reservoir forming substrate (second member) 20 is performed.
Specifically, as shown in FIG. 6D, the semiconductor element 200 is bonded to the upper surface of the reservoir forming substrate 20. Specifically, first, an adhesive 42 made of a thermoplastic resin material is applied to the central portion on the lower surface side of the semiconductor element 200. Then, the connection terminal 44 of the semiconductor element 200 is aligned in a so-called face-down state facing the reservoir forming substrate 20, and the semiconductor element 200 is heated and pressurized against the reservoir forming substrate 20.
Here, the gap between the connection terminal 44 and the reservoir forming substrate 20 is set to about several μm to 10 μm by adjusting the amount of adhesive applied and the amount of heating / pressurizing during bonding. This gap is embedded by plating the wiring 34 described later. Thereafter, the whole is cooled to cure the adhesive 42, and the semiconductor element 200 is fixed to the upper surface of the reservoir forming substrate 20.
In the present embodiment, the step of mounting the semiconductor element 200 on the reservoir forming substrate 20 is performed after the formation of the base pattern 34a. However, after mounting the semiconductor element 200 on the reservoir forming substrate 20, the base pattern 34a is formed. The pattern 34a may be formed.

Returning to the wiring 34 formation step again, as shown in FIG. 6E, plating 34b is deposited on the surface of the base pattern 34a. Specifically, electroless plating is performed by the following processing process.
First, in order to improve the wettability of the surface of the base pattern 34a and the connection terminal 44 and to remove the residue, 1 in an aqueous solution containing 0.01 to 0.1% hydrofluoric acid and 0.01 to 1% sulfuric acid. Soak for ~ 5 minutes. Alternatively, it may be immersed in an alkali-based aqueous solution such as 0.1 to 10% sodium hydroxide for 1 to 10 minutes.
Next, an alkaline aqueous solution with a pH of 9 to 13 based on sodium hydroxide is immersed in 20 to 60 ° C. for 1 second to 5 minutes to remove the oxide film on the surface. In addition, you may immerse the acidic aqueous solution of pH 1-3 based on 5-30% nitric acid for 1 second to 5 minutes in the temperature heated at 20-60 degreeC.

  Next, it is immersed in a zincate solution having a pH of 11 to 13 containing ZnO for 1 second to 2 minutes, and the surface of each wiring and connection terminal is replaced with Zn. Next, it is immersed in a 5 to 30% nitric acid aqueous solution for 1 to 60 seconds to separate Zn. Then, it is again immersed in a zincate bath for 1 second to 2 minutes, and dense Zn particles are deposited on the surface of the base pattern 34 a and the connection terminals 44.

Next, it is immersed in an electroless Ni plating bath to deposit Ni plating. This plating is deposited to a height of about 2 to 30 μm. The plating bath is a bath using hypophosphorous acid as a reducing agent, and has a pH of 4 to 5 and a bath temperature of 80 to 95 ° C. Due to the hypophosphorous acid bath, phosphorus co-deposits.
Further, the Ni surface may be replaced with Au by dipping in a replacement Au plating cradle. Au is formed to a thickness of about 0.05 μm to 0.3 μm. The Au bath is a cyan-free type, has a pH of 6 to 8, a bath temperature of 50 to 80 ° C., and is immersed for 1 to 30 minutes.

  In this manner, Ni or Ni—Au plating is deposited on the surface of the base pattern 34 a and the connection terminals 44. Here, as described above, since the through conductive portion 85 is formed by Ni—Au plating, the plating deposited on the base pattern 34 a comes into close contact with the through conductive portion 85. Therefore, as described above, the base pattern 34a is well formed without disconnection along the inclined surfaces 35 of the upper and lower steps of the step structure. Therefore, the plating deposited on the base pattern 34a. The wiring 34 formed by 34b is naturally not disconnected and has high conduction reliability.

Further, a thick Au plating may be applied on the Ni—Au wiring. This is because even if the base pattern 34a which is the base of the plating is formed thin, the electrical resistance can be reduced by thickening the plating. Further, as the plating deposited on the base pattern 34a, a conductive material containing Al, Ni-Cr, Cu, Ni, Au, or Ag, or a combination of two or more of them may be used. .
In addition, a water washing process is performed between each chemical process. As the washing tank, one having an overflow structure or a QDR mechanism is used, and N ₂ bubbling is performed from the bottom surface. Incidentally, bubbling method is a method of issuing a N2 methods and through such sintered bodies issue a N ₂ a hole such as resin tube. Thus, it is possible to perform a sufficiently effective rinse in a short time.

  Through the above process, as shown in FIG. 4, the plating 44a is deposited on the surface of the connection terminal 44 of the semiconductor element 200, and the plating 34b is deposited on the surface of the base pattern 34a. Here, the plating 34 b deposited from the base pattern 34 a in the vicinity of the lead electrode 90 is formed on the through conductive portion 85. In this way, the wiring 34 is formed by growing both plating until the plating 34b and the plating 44a are bonded to each other, and the wiring 34 electrically connects the connection terminal 44 of the semiconductor element 200 and the through conductive portion 85. Connected to.

As described above, since the through conductive portion 85 is connected to the lead electrode 90 that is connected to the piezoelectric element 300, the wiring 34 is connected to the connection terminal 44 of the semiconductor element 200 and the lead electrode through the through conductive portion 85. 90 is electrically connected. With this wiring 34, the semiconductor element 200 and the piezoelectric element 300 can be electrically connected.
Through the above steps, the droplet discharge head 1 is formed. Further, the device 500 can be formed by the step of forming the droplet discharge head 1.

As described in detail above, according to the manufacturing method of the droplet discharge head of the present embodiment, the lead electrode 90 that is electrically connected to the piezoelectric element 300 is disposed in the through hole 36 provided in the lower step portion of the step structure. Since the through-hole conductive portion 85 is formed by embedding the through-hole 36 with a conductive material such as plating, the upper surface side of the lower step portion can be electrically connected to the lead electrode 90 via the through-conductive portion 85. Become. Therefore, the wiring 34 connects between the through conductive portion 85 and the connection terminal 44 of the semiconductor element 200, and provides good conduction between the piezoelectric element 300 and the semiconductor element 200 through the through conductive portion 85. is doing.
Further, as described above, in this configuration, the reservoir forming substrate 20 has a step structure by forming the recess 20a. Since the base pattern 34a is formed along the surface where the upper and lower steps of the step structure are continuously connected by the inclined surface 35, and plating is deposited on the base pattern 34a, the wiring 34 is formed. As described above, the gap formed between the flow path forming substrate 10 and the reservoir forming substrate 20 does not cause the patterning failure of the base pattern 34a. Therefore, the wiring 34 constituted by the base pattern 34a is prevented from being disconnected. .
In addition, since this wiring is routed from the upper surface of the upper step portion to the upper surface of the lower step portion through the step surface, short-circuiting between adjacent wires is less likely to occur than when wire bonding is used. A droplet discharge head 1 that can be formed at a fine pitch and on which the semiconductor elements 200 are mounted at a high density is provided.

(Second Embodiment)
Next, a second embodiment of the droplet discharge head according to the present invention will be described with reference to FIG. In addition, the droplet discharge head in this embodiment is comprised from the thing different from the wiring structure and device which comprise the droplet discharge head 1 of the said 1st Embodiment. Note that portions having the same configuration as those of the droplet discharge head 1 in the first embodiment will be described with the same reference numerals, and description thereof will be omitted.
FIG. 7 is an explanatory diagram of a cross-sectional structure of a droplet discharge head according to the second embodiment. As shown in FIG. 7, in the droplet discharge head according to the second embodiment, the semiconductor element 200 is mounted on the reservoir forming substrate 20 in a so-called face-up state with the surface on the connection terminal 44 side facing up. This is different from the first embodiment.

  In the second embodiment, the wiring 38 is routed up to the semiconductor element 200 formed on the upper surface of the reservoir forming substrate 20, and the wiring 38 is connected to the connection terminal 44 of the semiconductor element 200 via the through conductive portion 85. The lead electrode 90 that is conductive to the piezoelectric element 300 is electrically connected. Further, a slope 39 is provided on the side surface of the semiconductor element 200, and the slope 39 makes it easy to route the wiring 38 to the upper surface of the semiconductor element 200. The slope 39 is made of an insulating material.

The wiring 38 includes a conductive base pattern 38a formed by, for example, sputtering as a physical vapor method, and Al, Ni—Cr, Cu, Ni, Au plated on the base pattern 38a, or And a conductive material containing Ag. Here, it is necessary to connect the lower surface side of the wiring 38 to the connection terminal 44 of the semiconductor element 200. In the present embodiment, the base pattern 38a having conductivity is used.
In this way, by patterning the metal film by the sputtering method, the conductive base pattern 38a can be formed. In addition, since the plating is deposited on the base pattern 38a, the electrical resistance as the wiring 38 can be reduced by increasing the film thickness by this plating.

  Further, the reservoir forming substrate 20 is provided with a recess 20a as in the first embodiment, and the reservoir forming substrate 20 has a step structure by the recess 20a. The upper and lower steps in the step structure are continuously connected by the inclined surface 35. Even in this configuration, the wiring 38 routed from the upper step portion of the step structure to the lower step portion through the inclined surface 35 is connected to the flow path forming substrate 10 and the reservoir forming substrate attached via the adhesive layer 3. Disconnection due to the gap T generated between the wiring 20 and the wiring structure including the wiring 38 that is prevented in the same manner as in the first embodiment, is arranged on the inclined surface 35 with a fine pitch, and has high conduction reliability. And devices.

Next, a method for manufacturing a droplet discharge head according to the second embodiment will be described with reference to the sectional process diagram of FIG. Note that the process from the formation process of the reservoir forming substrate 20 to the adhering process with the flow path forming substrate 10 is the same as that of the first embodiment shown in FIGS. .
First, as shown in FIG. 8A, the semiconductor element 200 is mounted on a predetermined position of the reservoir forming substrate 20 via an adhesive layer (not shown). A slope 39 is provided on the side surface of the semiconductor element 200. At this time, the reservoir forming substrate 20 has a step structure, and a through conductive portion 85 is provided in the lower step portion of the step structure. Further, the step surface that continues the upper and lower steps of the step structure is an inclined surface 35 that forms an acute angle.

Next, as shown in FIG. 8B, the conductive film 41 such as Al, Ni—Cr, Cu, Ni, Au, or Ag constituting the conductive base pattern 38a formed by sputtering is used. It is formed on the entire surface of the reservoir forming substrate 20. In the present embodiment, NiCr / Au is sputtered as the conductive film 41.
At this time, the conductive film 41 is formed along the inclined surface 35 in which the upper and lower steps of the step structure provided on the reservoir forming substrate 20 are continuous. Since the inclined surface 35 smoothly connects the lower step surface and the upper step surface as described above, the inclined surface 35 is uniformly patterned.

  Thereafter, as shown in FIG. 8C, a resist mask R patterned into the base pattern shape of the wiring 38 is formed on the conductive film 41, and etching is performed through the resist mask R. At this time, the conductive film 41 is uniformly formed between the upper step portion and the lower step portion along the inclined surface 35, and a good base pattern 38a is formed by etching as shown in FIG. Is done. Since the base pattern 38a in this embodiment has conductivity unlike the above-described embodiment, the base pattern 38a may be formed so as to cover the entire top surface of the through conductive portion 85. Therefore, the base pattern 38 a is electrically connected between the connection terminal 44 of the semiconductor element 200 and the through conductive portion 85.

  Here, since the base pattern 38a is a thin film, a film thickness is required to sufficiently function as a wiring. Therefore, as shown in FIG. 8E, the plating 38b is deposited on the surface of the base pattern 38a in the same manner as in the embodiment. In this embodiment, since the base pattern 38a has conductivity, electrolytic plating is performed. Thereby, plating with a sufficient film thickness can be deposited on the base pattern 38a. Therefore, the electrical resistance as the wiring 38 is reduced and good electrical connection is possible.

In the second embodiment, the semiconductor element 200 is mounted on the reservoir forming substrate 20 in a face-up state. The wiring 38 is routed from the upper surface of the semiconductor element 200 mounted on the upper step portion of the step structure provided on the reservoir forming substrate 20 to the penetrating conductive portion 85 provided on the lower step portion of the step structure. The connection terminal (second conductive portion) 44 of the semiconductor element 200 is electrically connected to the lead electrode (first conductive portion) 90 on the flow path forming substrate 10 via the conductive portion 85.
As described above, the wiring 38 can provide a droplet discharge head including a wiring structure including a wiring having high conduction reliability and a fine pitch, as in the first embodiment, and a device.

  The above-described droplet discharge head, wiring structure, and device are not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.

(Droplet discharge device)
Next, an embodiment of the droplet discharge device of the present invention will be described with reference to FIG. As the liquid droplet ejection apparatus according to this embodiment, an ink jet recording apparatus including the above-described liquid droplet ejection head 1 will be described.

  The droplet discharge head 1 constitutes a part of a recording head unit having an ink flow path communicating with an ink cartridge or the like, and is mounted on an ink jet recording apparatus. As shown in FIG. 9, the recording head units 1A and 1B having the droplet discharge heads are detachably provided with cartridges 2A and 2B constituting ink supply means, and the recording head units 1A and 1B are mounted. The carriage 9 is attached to a carriage shaft 5 attached to the apparatus main body 4 so as to be movable in the axial direction.

  The recording head units 1A and 1B, for example, are configured to eject a black ink composition and a color ink composition, respectively. Then, the driving force of the driving motor 6 is transmitted to the carriage 9 via a plurality of gears and a timing belt 7 (not shown), so that the carriage 9 on which the recording head units 1A and 1B are mounted moves along the carriage shaft 5. It is like that. On the other hand, the apparatus body 4 is provided with a platen 8 along the carriage shaft 5, and a recording sheet S which is a recording medium such as paper fed by a paper feed roller (not shown) is conveyed onto the platen 8. It is like that. Since the ink jet recording apparatus having the above configuration includes the above-described droplet discharge head 1, the ink jet recording apparatus is small, highly reliable, and low in cost.

  Although FIG. 9 shows an ink jet recording apparatus as a single printer as an example of the droplet discharge apparatus of the present invention, the present invention is not limited to this, and a printer realized by incorporating such a droplet discharge head. It can also be applied to units. Such a printer unit is attached to a display device such as a television or an input device such as a whiteboard, and is used to print an image displayed or input by the display device or the input device.

  The droplet discharge head can also be applied to a droplet discharge apparatus for forming various devices by a liquid phase method. In this embodiment, as the functional liquid discharged from the droplet discharge head, a liquid crystal display device forming material for forming a liquid crystal display device, an organic EL forming material for forming an organic EL display device, an electronic circuit A material including a wiring pattern forming material for forming a wiring pattern is used. According to the manufacturing process in which these functional liquids are selectively arranged on the substrate by the droplet discharge device, the pattern arrangement of the functional material can be performed without going through the photolithography process. For example, a liquid crystal display device, an organic EL device, a circuit, etc. A board | substrate etc. can be manufactured cheaply.

It is a perspective view showing one embodiment of a droplet discharge head. FIG. 3 is a partially cutaway view of a perspective configuration view of a droplet discharge head as viewed from below. It is a cross-sectional block diagram in the AA arrow of FIG. It is a figure which shows one Embodiment of the device which comprises some droplet discharge heads. It is expansion explanatory drawing of the plating junction part of wiring and the connection terminal of a semiconductor element. It is a figure which shows one Embodiment of the manufacturing process of a droplet discharge head. It is a figure which shows 2nd Embodiment of a droplet discharge head. It is a figure which shows the manufacturing process of the droplet discharge head of 2nd Embodiment. It is a figure which shows one Embodiment of a droplet discharge apparatus. It is a sectional side view showing the configuration of a conventional droplet discharge head.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Droplet discharge head, 10 ... Channel formation board | substrate (1st member), 12 ... Pressure generating chamber, 20 ... Reservoir formation board | substrate (2nd member), 20a ... Recessed part, 34 ... Wiring, 36 ... Through-hole, 38 ... Wiring, 44 ... Connection terminal, 85 ... Penetration conductive part, 120 ... Silicon single crystal substrate (precursor substrate), 200 ... Semiconductor element, 300 ... Driving element (piezoelectric element), 500 ... Device, 500a ... Wiring structure

Claims (15)

A second member is provided on the first member, and the second conductive portion provided on the second member and the first conductive portion provided on the upper surface of the first member are electrically connected by wiring. In the wiring structure,
The second member includes a step structure, and the second conductive portion is provided in the upper step portion of the step structure, and the lower step portion of the step structure penetrates the lower step portion and is electrically connected to the first conductive portion. A penetrating conductive part is provided,
The wiring is routed from the upper surface of the upper step portion to the upper surface of the lower step portion through a step surface that makes the upper step portion and the lower step portion continuous, and the second conductive portion and the through conductive portion. A wiring structure characterized by connecting the two.   The wiring structure according to claim 1, wherein the step surface is formed to be inclined with respect to the upper surface of the lower step portion, and the inclination angle is an acute angle.   A device comprising the wiring structure according to claim 1, wherein the second conductive portion is a connection terminal of a semiconductor element.   The through conductive portion is made of any one of a metal material selected from the group consisting of Ni—Cr, Cu, Ni, Au, and Ag, an alloy of a metal material selected from the group, a brazing material, or a conductive resin material. The device according to claim 3, wherein   The wiring is composed of a base pattern made of a photosensitive resin containing a catalyst that promotes plating deposition, and a conductive material containing Al, Ni-Cr, Cu, Ni, Au, or Ag deposited on the base pattern. The device according to claim 3, wherein the device is a device.   The wiring is composed of a conductive base pattern formed by a physical vapor phase method and a conductive material containing Al, Ni-Cr, Cu, Ni, Au, or Ag deposited on the base pattern. The device according to claim 3 or 4, characterized by the above.   The connection terminal of the semiconductor element is formed of a metal material selected from the group consisting of Al, Ni—Cr, Cu, Ni, Au, and Ag, or an alloy of a metal material selected from the group. The device according to claim 5 or 6.   The device according to claim 3, wherein the semiconductor element is held on an upper surface of the second member via an adhesive layer. A device manufacturing method, wherein a second member is provided on a first member, and a semiconductor element provided on the second member and a first conductive portion provided on an upper surface of the first member are connected by wiring. In
Etching a precursor substrate that serves as a precursor of the second member to provide a step structure, and forming a second member by forming a through hole in a lower step portion of the step structure;
Providing the second member on the first member by positioning so that a part of the first conductive portion is disposed in the through hole; and
A step of embedding a conductive material in the through hole to form a through conductive portion in the lower stage portion;
Providing a semiconductor element on the upper stage;
Forming a wiring that is routed through a stepped surface that connects the upper step portion and the lower step portion to connect the connection terminal of the semiconductor element and the through conductive portion;
A device manufacturing method comprising: The precursor substrate is composed of a silicon substrate having a plane orientation (1, 0, 0),
The device manufacturing method according to claim 9, wherein the step structure is formed by anisotropic etching of the silicon substrate.   For the wiring, after forming a base pattern made of a photosensitive resin containing a catalyst that promotes the deposition of plating, a conductive material containing Al, Ni-Cr, Cu, Ni, Au, or Ag is deposited on the base pattern. The device manufacturing method according to claim 9, wherein the device is formed.   The connection terminal of the semiconductor element is formed of a metal material selected from the group consisting of Al, Ni—Cr, Cu, Ni, Au, and Ag, or an alloy of a metal material selected from the group. The manufacturing method of the device as described in any one of Claims 9-11. A flow path forming substrate provided with a pressure generating chamber communicating with a nozzle for discharging droplets, a driving element disposed on the upper surface side of the flow path forming substrate and causing a pressure change in the pressure generating chamber; In a droplet discharge head comprising: a sealing substrate provided to cover the driving element provided on the flow path forming substrate; and a semiconductor element disposed on the upper surface side of the sealing substrate and driving the driving element. ,
The sealing substrate is provided with a step structure, and the semiconductor element is provided in the upper step portion of the step structure, and the lower step portion of the step structure penetrates the lower step portion and is electrically connected to the wiring portion of the driving element. A penetrating conductive part is provided,
A wiring routed from the upper surface of the upper step portion to the upper surface of the lower step portion through a step surface that connects the upper step portion and the lower step portion to each other between the through conductive portion and the connection terminal of the semiconductor element. A droplet discharge head characterized by being connected to each other. A flow path forming substrate provided with a pressure generating chamber communicating with a nozzle for discharging droplets, a driving element disposed on the upper surface side of the flow path forming substrate and causing a pressure change in the pressure generating chamber; A droplet discharge head comprising: a sealing substrate that covers the driving element provided on the flow path forming substrate; and a semiconductor element that is disposed on an upper surface side of the sealing substrate and drives the driving element. A manufacturing method comprising:
Etching a silicon substrate that is a precursor of the sealing substrate to form a step structure, forming a through hole in a lower step portion of the step structure, and forming the sealing substrate;
Providing the sealing substrate on the flow path forming substrate by aligning the wiring portion to be connected to the driving element in the through hole; and
Forming a through conductive portion in the lower step by embedding a conductive material in the through hole; and
Providing a semiconductor element on the upper stage;
Forming a wiring that is routed through a stepped surface that connects the upper step portion and the lower step portion to connect the connection terminal of the semiconductor element and the through conductive portion;
A method for manufacturing a droplet discharge head, comprising: A droplet discharge apparatus comprising the droplet discharge head according to claim 13.

Images