JP2015123691A - Liquid ejection head and liquid ejection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid ejection head suppressing corrosion of wiring caused by solvent, and further to provide a liquid ejection device.SOLUTION: A liquid ejection head ejecting liquid containing solvent comprises: a flexible substrate 212; and a rigid substrate 250 bonded to the flexible substrate 212. The flexible substrate 212 comprises: a base material 213; a wiring layer 214 provided on the base material 213; a plated layer 215 provided across a whole area on the wiring layer 214; and a protective layer 216 provided on the plated layer 215. The rigid substrate 250 is bonded to a part of the plated layer 215 where the protective layer 216 is not provided.

Description

  The present invention relates to a liquid ejecting head and a liquid ejecting apparatus that eject a liquid containing a solvent, and more particularly to an ink jet recording head and an ink jet recording apparatus that eject ink as a liquid.

  A liquid ejecting apparatus typified by an ink jet recording apparatus such as an ink jet printer or a plotter has a liquid ejecting head capable of ejecting liquid from a liquid storing means such as a cartridge or tank in which the liquid is stored as droplets.

  Such a liquid ejecting head includes a flow path that communicates with a nozzle opening that ejects ink as liquid, and a pressure generation unit that causes a pressure change in the liquid in the flow path to eject ink from the nozzle opening. There is an ink jet recording head. Examples of pressure generating means mounted on the ink jet recording head include a longitudinal vibration type piezoelectric actuator, a flexural vibration type piezoelectric actuator, a heating element, and a device using an electrostatic force.

  Here, the ink jet recording head includes a head main body that ejects liquid, and a flow path member that is provided on a surface opposite to the liquid ejection surface of the head main body. (See, for example, Patent Documents 1 and 2).

  Such an ink jet recording head includes a wiring board made of a flexible board connected to the head body, and a circuit board made of a rigid board held by the flow path member and connected to the wiring board. The signal is supplied to the pressure generating means via the circuit board and the wiring board.

  Also, the wiring of the flexible substrate used in the ink jet recording head is configured by covering the terminal portion of the wiring layer such as copper foil with gold plating, and the terminal portion covered with the gold plating of the wiring layer is configured as a circuit board or a mounting member. In addition, the wiring layer that is not covered with the gold plating is protected by the resist layer.

JP 2013-176963 A JP 2013-176862 A

However, when ink containing a solvent for an ink jet recording head is ejected, there is a problem that the solvent contained in the ink volatilizes and the volatilized solvent corrodes the wiring on the wiring board.
Specifically, the solvent contained in the ink volatilizes, and the volatilized solvent passes through the resist layer and accumulates on the wiring layer, so that the wiring layer may be corroded.

In addition, for the wiring in which the terminal part connected to the terminal part of the other member is gold-plated, the gold plating is altered by heat or the like when connecting to the terminal part of the other member, and the altered part is corroded by the solvent. May end up. The alteration of the gold plating is not limited to that caused by heat, and even at room temperature, the alteration may occur due to a diffusion phenomenon between metals, and corrosion may occur.
Such a problem exists not only in an ink jet recording head but also in a liquid ejecting head that ejects liquid other than ink.

  In view of such circumstances, an object of the present invention is to provide a liquid ejecting head and a liquid ejecting apparatus that suppress corrosion of wiring due to a solvent.

An aspect of the present invention that solves the above problems is a liquid ejecting head that ejects a liquid containing a solvent, and includes a flexible substrate and a rigid substrate bonded to the flexible substrate, and the flexible substrate includes a base. Material, a wiring layer provided on the substrate, a plating layer provided over the entire surface of the wiring layer, and formed of a material having higher corrosion resistance to the solvent than the wiring layer, and the plating layer And a protective layer having an insulating property provided thereon, wherein the rigid substrate is bonded to the plating layer on which the protective layer is not provided.
In such an aspect, by providing a plating layer in the wiring layer, even if the solvent contained in the liquid volatilizes and permeates the resist, the corrosion of the plating layer is suppressed by the solvent. Problems such as disconnection can be suppressed. Further, the manufacturing cost can be reduced as compared with the case where the protective layer is provided with a plating layer.

  Here, the plating layer between the wiring layer and the rigid substrate, in which the protective layer is not formed and is not joined to the rigid substrate, is a solvent layer with respect to the protective layer. It is preferably covered with a sealing material made of a material having low permeability. According to this, it can suppress by the sealing material that the solvent contained in the liquid evaporates and the volatilized solvent reaches | attains on the plating layer which is not covered with the protective layer with the sealing material. Therefore, even when the plated layer is altered by heat or the like, corrosion of the plated layer can be suppressed.

Another aspect of the present invention is a liquid ejecting head that ejects a liquid containing a solvent, and includes a flexible substrate and a rigid substrate bonded to the flexible substrate, and the flexible substrate includes a base material A wiring layer provided on the substrate, a plating layer provided at least in a region bonded to the rigid substrate on the wiring layer, and an insulating protective layer provided on the wiring layer The plating layer between the wiring layer and the rigid substrate, the protective layer is not provided, and the region not bonded to the rigid substrate is covered with a sealing material. The liquid ejecting head is characterized by the above.
In such an aspect, the solvent contained in the liquid volatilizes, and the volatilized solvent can be prevented from reaching the plating layer not covered with the protective layer by the sealing material. Therefore, even when the plated layer is altered by heat or the like, corrosion of the plated layer can be suppressed.

  Here, the sealing material is preferably an epoxy adhesive. According to this, permeation | transmission of a solvent can further be suppressed by using a specific material as a sealing material.

  Moreover, it is preferable that the end surface of the said wiring layer is covered with the said sealing material. According to this, corrosion of the wiring due to the solvent adhering to the end face of the wiring layer can be suppressed.

According to another aspect of the invention, there is provided a liquid ejecting apparatus including the liquid ejecting head according to the above aspect.
In this aspect, it is possible to realize a liquid ejecting apparatus that can eject a liquid containing a solvent and suppress corrosion of the wiring.

FIG. 2 is an exploded perspective view of a recording head according to Embodiment 1 of the invention. FIG. 3 is a plan view of the recording head according to the first embodiment of the invention. FIG. 3 is a cross-sectional view of the recording head according to the first embodiment of the invention. FIG. 2 is an enlarged cross-sectional view of a main part of the recording head according to Embodiment 1 of the invention. FIG. 6 is an enlarged cross-sectional view of a main part of a recording head according to Embodiment 2 of the present invention. 1 is a schematic perspective view of a recording apparatus according to an embodiment of the present invention.

Hereinafter, the present invention will be described in detail based on embodiments.
(Embodiment 1)
1 is an exploded perspective view of an ink jet recording head that is an example of a liquid ejecting head according to Embodiment 1 of the present invention. FIG. 2 is a plan view of the ink jet recording head according to Embodiment 1 of the present invention. FIG. 3 is a cross-sectional view taken along the line AA ′ of FIG.

  As shown in the drawing, an ink jet recording head 200 which is an example of a liquid ejecting head of the present embodiment includes a head main body 210 that ejects ink droplets as a liquid, a flow path member 220 that supplies ink to the head main body 210, and a flow A circuit board 250 held by the path member 220, an external wiring board 260 connected to the circuit board 250, and a cover head 270 are provided.

  The head main body 210 of this embodiment is provided with a liquid ejecting surface 211a in which a nozzle opening 211 that ejects ink containing a solvent is opened. Here, examples of the ink containing a solvent include so-called UV ink and solvent ink that absorb and cure ultraviolet rays.

  Further, inside the head main body 210 (not shown), a flow path communicating with the nozzle opening 211, a pressure generating means for causing a pressure change in the ink in the flow path, and the like are provided. As such a pressure generating means, for example, the volume of the liquid flow path is changed by deformation of a piezoelectric actuator having a piezoelectric material exhibiting an electromechanical conversion function, thereby causing a pressure change in the ink in the liquid flow path, so that the ink droplets from the nozzle openings That injects ink droplets, injects ink droplets from the nozzle openings by bubbles generated by the heat generated by the heating elements, and generates electrostatic force between the diaphragm and the electrode. For example, a so-called electrostatic actuator that ejects ink droplets from the nozzle openings by deforming the diaphragm by electrostatic force may be used.

A plurality of nozzle openings 211 opening in the liquid ejection surface 211 a of the head body 210 are arranged in parallel to form a row of nozzle openings 211. In the present embodiment, the direction in which the nozzle openings 211 are arranged side by side is referred to as a first direction X. In the present embodiment, two rows of nozzle openings 211 arranged in parallel in the first direction X are provided in a direction orthogonal to the first direction X. In the present embodiment, a direction orthogonal to the first direction X is referred to as a second direction Y. In the present embodiment, a direction orthogonal to the first direction X and the second direction Y is referred to as a third direction Z. In the third direction Z, the liquid ejection surface 211a side is the Z1 side, and the liquid ejection surface 211a. The opposite side is referred to as the Z2 side.
A cover head 270 that protects the nozzle body 211 in a state where the nozzle opening 211 is exposed is fixed to the liquid ejecting surface 211a side where the nozzle opening 211 of the head body 210 opens.

  Further, the wiring board 212 is drawn from the Z2 side opposite to the Z1 side, which is the liquid ejection surface 211a of the head main body 210. The wiring board 212 is made of a flexible board, which will be described in detail later, and is connected to a pressure generating means or the like (not shown) of the head body 210.

  The flow path member 220 is fixed to the Z2 side opposite to the Z1 side, which is the liquid ejecting surface 211a of the head main body 210. In the present embodiment, the head main body 210 is fixed to the flow path member 220 by two screw members 271 that are screwed into the flow path member 220.

  The flow path member 220 includes a flow path member main body 221 and both side surfaces of the flow path member main body 221, in the present embodiment, the first lid member 222 and the second lid member 223 provided on both sides in the second direction Y, respectively. It comprises. In the present embodiment, in the second direction Y, the side on which the first lid member 222 is provided is referred to as the Y1 side, and the side on which the second lid member 223 is provided is referred to as the Y2 side.

The flow path member 220 has a liquid flow path 400 for supplying ink to the head main body 210 from a liquid storage means (not shown) in which ink is stored as a liquid and collecting the ink from the head main body 210 to the liquid storage means. Is provided. The liquid flow path 400 of the present embodiment includes a supply flow path 410 and a recovery flow path 420. In the supply flow path 410 and the recovery flow path 420, liquid storage means for storing ink is directly or via a tube. It is connected.
The supply flow path 410 is a forward path for supplying ink from the liquid storage means to the head main body 210, and is provided on one end side in the first direction X of the flow path member 220.

  The recovery flow path 420 is a return path for recovering ink from the head main body 210 to the liquid storage means, and is provided on the other end side of the flow path member 220 in the first direction X. In the present embodiment, in the first direction X, the one end side where the supply flow path 410 is provided is referred to as the X2 side, and the other end side where the recovery flow path 420 is provided is referred to as the X1 side.

Further, the supply channel 410 is provided with a filter 224 for removing foreign matters such as bubbles and dust contained in the ink. The ink supplied from the liquid storage means passes through the filter 224 to remove foreign matter and is supplied to the head main body 210.
In addition, the flow path member main body 221 is provided with a first recess 225 that opens on one side in the second direction Y and a second recess 226 that opens on the other side in the second direction Y. .

The opening of the first recess 225 of the flow path member 220 is covered by the first lid member 222, and a first space 430 is formed between the first recess 225 and the first lid member 222.
The opening of the second recess 226 is covered with the second lid member 223, and a second space 431 is formed between the second recess 226 and the second lid member 223.

  And the circuit board 250 which is the rigid board | substrate of this embodiment is hold | maintained in the 2nd space part 431. FIG. A communication hole 228 that communicates the second space 431 and the surface on the Z1 side is provided on the head body 210 side of the flow path member 220, that is, on the Z1 side. The wiring board 212 of the head main body 210 is inserted through the communication hole 228 and connected to the circuit board 250 in the second space portion 431.

In addition, an external wiring connection hole 229 that communicates the second space portion 431 and the outside is provided on the Z2 side of the flow path member 220. The external wiring board 260 is inserted through the external wiring connection hole 229 and connected to the circuit board 250 in the second space portion 431. The external wiring connection hole 229 is sealed with a seal member (not shown). This suppresses ink from entering from the external wiring connection hole 229. The external wiring board 260 is made of a flexible board (FPC) or the like.
In this way, a print signal from an external control circuit or the like is supplied to the pressure generating means of the head main body 210 as a drive signal via the external wiring board 260, the circuit board 250, and the wiring board 212.

Here, the wiring board 212 and the circuit board 250 will be described in detail with further reference to FIG. Note that. FIG. 4 is an enlarged cross-sectional view of the main parts of the wiring board and the circuit board.
As shown in FIG. 4, the wiring substrate 212 is made of a flexible substrate (FPC) or a COF in which a driving circuit such as a driving IC is mounted on the flexible substrate, and is provided on the substrate 213 and the substrate 213. The wiring layer 214, a plating layer 215 provided on the wiring layer 214, and an insulating protective layer 216 provided on at least a part of the plating layer 215 are provided. In the present embodiment, the wiring layer 214 and the plating layer 215 of the wiring board 212 constitute a wiring.

As the base 213, a flexible film formed of an insulating material such as a polyester film or a polyimide film can be used.
The wiring layer 214 is made of a conductor formed on the base material 213 and is patterned into a predetermined shape. Examples of the material for the wiring layer include copper (Cu) and aluminum (Al). The wiring layer can be formed, for example, by bonding a copper foil to the base material 213 and then patterning it into a predetermined shape. Of course, the method of forming the wiring layer is not limited to this, and it may be formed by electroless plating or the like.

  The plating layer 215 is formed by plating over the entire surface of the wiring layer 214. The material of the plating layer 215 has higher corrosion resistance than the material of the wiring layer 214 with respect to the solvent contained in the ink, and does not impair the flexibility of the wiring substrate 212. In this embodiment, since the ink contains a solvent such as a monomer, the ink has higher corrosion resistance than the material of the wiring layer 214 with respect to the solvent contained in the ink, and the flexibility of the wiring board 212 is increased. Examples of the material that does not deteriorate include at least one selected from the group consisting of gold (Au), tin (Sn), platinum (Pt), and the like. The ink may contain an acrylate monomer or γ-butyrolactone. The plated layer 215 may be a single layer made of at least one material selected from the above materials, or may be a laminate of a plurality of layers. Further, the plating layer 215 may be formed directly on the wiring layer 214, or an adhesion layer such as nickel may be provided. Incidentally, an adhesion layer such as nickel can also be formed by plating. In addition, when tin is used as the plating layer 215, whiskers may be formed when stress is applied to the wiring board 212. Therefore, the plating layer 215 is made of a material that does not easily generate whiskers, that is, gold. (Au) or the like is preferably used. Needless to say, when tin is used for the plating layer 215, the generation of whiskers may be suppressed by adding lead or heat treatment as a countermeasure against whiskers. The plating layer 215 is preferably made of a material having a lower ionization tendency than the material of the wiring layer 214. Although this will be described in detail later, the plating layer 215 is provided to prevent the solvent contained in the ink from volatilizing and the volatilized solvent from being accumulated on the wiring layer 214 and corroding. By using a material that is less reactive than the wiring layer 214 as the 215, that is, a material that has a low ionization tendency, even if a solvent accumulates on the plating layer 215, the plating layer 215 can be prevented from corroding. . That is, when copper (Cu) is used for the wiring layer 214, it is preferable to use a material having a smaller ionization tendency than copper (Cu), that is, gold (Au) or the like for the plating layer 215. When aluminum (Al) is used for the wiring layer 214, the plating layer 215 is made of a material having a smaller ionization tendency than aluminum (Al), that is, gold (Au), tin (Sn), platinum (Pt ) Etc., at least one material selected from the group consisting of, etc. can be used. The plating method for forming such a plating layer 215 is not particularly limited, and may be electrolytic plating or electroless plating.

  Such a plating layer 215 is formed over at least the surface of the wiring layer 214 on the Y1 side that is opposite to the Y2 side that is the base material 213 side. Of course, the plating layer 215 may be formed over the entire surface other than the surface of the wiring layer 214 on the substrate 213 side, that is, over the end surface. Note that the end surface of the wiring layer 214 is a direction orthogonal to the second direction Y that is the stacking direction, that is, a surface in the first direction X and the third direction Z. That is, the fact that the plating layer 215 is provided over the entire surface of the wiring layer 214 means that at least the surface of the wiring layer 214 on the Y1 side that is opposite to the Y2 side that is the surface bonded to the base material 213. It is formed over the entire surface. Of course, even if the plating layer 215 is provided over the entire surface of the wiring layer 214, it is not necessary to make the wirings conductive by covering the wirings with the plating layer 215 in order to prevent a short circuit. Further, in the present embodiment, the configuration in which the plating layer 215 is directly provided on the wiring layer 214 is illustrated, but the present invention is not particularly limited to this, and as described above, between the wiring layer 214 and the plating layer 215. An adhesive layer or the like may be provided. That is, the term “on the wiring layer 214” includes both the state immediately above the wiring layer 214 and a state in which another member is interposed (upward).

  The protective layer 216 is made of an insulating material and is formed on a region other than the terminal portion 217 connected to other members of the plating layer 215. As such a protective layer 216, a solder resist such as a thermosetting epoxy resin can be used. Further, the protective layer 216 can be formed in a predetermined shape by applying a resist material coating solution by a screen printing method, for example. In addition, the protective layer 216 is not limited to a solder resist, For example, you may adhere | attached insulating films, such as a polyimide film, with the adhesive agent.

  Such a protective layer 216 is formed on the plated layer 215, that is, on at least the surface of the plated layer 215 on the Y1 side opposite to the Y2 side on the wiring layer 214 side. Of course, the protective layer 216 may be formed over the end surface of the plating layer 215. Note that the end surface of the plating layer 215 is a direction orthogonal to the second direction Y that is the stacking direction, that is, a surface in the first direction X and the third direction Z. That is, the protective layer 216 being formed on the plated layer 215 means that it is formed on at least the surface of the plated layer 215 on the Y1 side opposite to the Y2 side on the wiring layer 214 side. Further, in the present embodiment, the configuration in which the protective layer 216 is directly provided on the plating layer 215 is illustrated, but the present invention is not particularly limited thereto, and another layer is provided between the plating layer 215 and the protective layer 216. You may make it provide. Further, the protective layer 216 may be formed over the entire surface of the base 213 on the Y1 side.

  The plating layer 215 not covered with the protective layer 216 becomes the terminal portion 217 of the wiring board 212, and the terminal portion 217 is connected to the terminal portion 251 of the circuit board 250. In the present embodiment, the terminal portion 217 of the wiring board 212 and the terminal portion 251 of the circuit board 250 are joined by the solder 218. Of course, the method of joining the terminal portion 217 of the wiring board 212 and the terminal portion 251 of the circuit board 250 is not particularly limited to this, and an anisotropic conductive adhesive (ACP, ACF) or non-conductive adhesive (NCP) , NCF) or the like may be used. Further, although not shown, the plating layer 215 is also provided with a terminal portion connected to the external wiring board 260, a terminal portion for mounting a drive circuit, and the like. Like the terminal portion 217 connected to the terminal portion 251 of 250, it is not covered with the protective layer 216.

  Thus, by forming the plating layer 215 over the entire surface of the wiring layer 214, it is possible to suppress the wiring layer 214 from being corroded by the solvent contained in the ink. That is, if the wiring layer 214 is only covered with the protective layer 216, the solvent contained in the ink volatilizes, and the components contained in the solvent permeate the protective layer 216 and accumulate on the wiring layer 214. It will corrode. In the present embodiment, since the solvent that has passed through the protective layer 216 accumulates on the plating layer 215, the plating layer 215 has corrosion resistance to the solvent, thereby suppressing the corrosion of the plating layer 215 and the wiring layer 214. Problems such as disconnection due to corrosion can be suppressed.

  Further, when the terminal portion 217 of the wiring board 212 and the terminal portion 251 of the circuit board 250 are heated at the time of joining, the plating layer 215 of the wiring board 212 is altered. Specifically, a metal-to-metal diffusion phenomenon occurs between the plated layer 215 of the wiring board 212 and the terminal portion 251 of the circuit board 250, resulting in deterioration. If the plated layer 215 is altered in this way, the corrosion resistance of the plated layer 215 to the solvent is lowered. Therefore, when the volatilized solvent comes into contact with the terminal portion 217 where the plated layer 215 is altered, the altered plated layer 215 may be corroded. There is. In addition, when it heats at the time of the junction of the terminal part 217 of the wiring board 212, and the terminal part 251 of the circuit board 250, the diffusion phenomenon of metals will be accelerated | stimulated, solder joining, anisotropic conductive adhesive, and Even bonding using a non-conductive adhesive is heated because of reliability and shortening of the curing time. Of course, the diffusion phenomenon between the metals occurs even at room temperature that is not heated, and the plating layer 215 is altered.

  Therefore, in the present embodiment, the plating layer 215 between the wiring layer 214 and the circuit board 250, the protective layer 216 is not formed, and the region not joined to the terminal portion 251 of the circuit board 250 is , And is covered with a sealing material 252. That is, the sealing material 252 is provided on the plating layer 215 other than the region joined to the terminal portion 251 of the circuit board 250 in the terminal portion 217 that is not covered by the protective layer 216 of the plating layer 215. In this embodiment, the wiring board 212 (base material 213, protective layer 216, etc.) and the circuit board 250 are bonded together by the sealing material 252. Such a sealing material 252 is preferably a material that is less permeable to the solvent contained in the ink than the protective layer 216, and for example, an epoxy adhesive or the like can be used. That is, the same material as the protective layer 216 can be used as the sealing material 252, but the sealing material 252 preferably has a higher crosslink density than the protective layer 216. In other words, the wiring board 212 includes a portion where flexibility is required and a portion where flexibility is not so required, such as the terminal portion 217. Since the protective layer 216 is provided in a portion where flexibility is required, it is preferable to use a material having a low crosslink density. However, if the crosslink density is low, components contained in the ink are easily transmitted. On the other hand, since the sealing material 252 is provided in the vicinity of the terminal portion 217 where flexibility is not required so much, a material having a higher crosslinking density than the protective layer 216 can be used. It becomes difficult to penetrate the components.

  Further, the same sealing material 253 as the sealing material 252 is formed to cover the end surface of the wiring layer 214. That is, when the end surface of the wiring layer 214 is not covered with the plating layer 215, the end surface of the wiring layer 214 is covered with the sealing material 253 because corrosion occurs due to the accumulation of the solvent on the end surface of the wiring layer 214. Thus, corrosion of the end face of the wiring layer 214 can be suppressed. In this embodiment, in FIG. 4, the sealing material 253 covers only the end surface of the wiring layer 214 in the third direction Z, but of course, the present invention is not limited to this. It is a direction perpendicular to the second direction Y, which is the stacking direction, that is, a surface in the first direction X and the third direction Z. The sealing material 253 may cover the exposed end surface of the wiring layer 214, although not particularly illustrated.

  By providing the sealing material 252 in this manner, it is possible to suppress the volatilized solvent from being accumulated in the altered plating layer 215 in the terminal portion 217 of the wiring board 212. Therefore, it is possible to suppress the plating layer 215 that has deteriorated in the terminal portion 217 of the wiring board 212 from being corroded by the solvent. In addition, by covering the portion of the end surface of the wiring layer 214 that is not covered with the plating layer 215 with the sealing material 253, it is possible to suppress accumulation of the volatilized solvent on the end surface of the wiring layer 214. End surface corrosion can be suppressed.

  Furthermore, in this embodiment, since the wiring board 212 and the circuit board 250 are joined by the sealing material 252, the joining strength between the wiring board 212 and the circuit board 250 is improved. Therefore, the electrical bonding strength between the terminal portion 217 of the wiring board 212 and the terminal portion 251 of the circuit board 250 is also improved, and problems such as disconnection can be suppressed.

  In the ink jet recording head 200 of this embodiment, ink from a liquid storage unit (not shown) is supplied to the head main body 210 via the supply flow path 410 of the flow path member 220, and the flow path of the head main body 210 is connected to the nozzle. After filling with ink up to the opening 211, ink droplets are ejected from the nozzle opening 211 by driving the pressure generating means according to the drive signal. Further, the ink introduced into the head main body 210 flows out to the recovery flow path 420 of the flow path member 220 and is returned to the liquid storage means via the recovery flow path 420. In other words, the ink in the liquid storage means is supplied to the head main body 210 via the supply flow path 410 and is recovered from the head main body 210 to the liquid storage means via the recovery flow path 420.

  In the present embodiment, the ink jet recording head 200 that circulates the ink is illustrated. However, the present invention is not particularly limited to this, and is not circulated. That is, the ink is merely supplied from the liquid storage means to the ink jet recording head 200. An ink jet recording head may be used.

(Embodiment 2)
FIG. 5 is an enlarged cross-sectional view of a main part of an ink jet recording head which is an example of a liquid jet head according to Embodiment 2 of the present invention. In addition, the same code | symbol is attached | subjected to the member similar to Embodiment 1 mentioned above, and the overlapping description is abbreviate | omitted.

  As shown in FIG. 5, the ink jet recording head of this embodiment includes a wiring board 212A made of a flexible board and a circuit board 250 made of a rigid board, and these wirings are connected to each other.

  The wiring board 212A is made of a flexible board (FPC) or a COF in which a driving circuit such as a driving IC is mounted on the flexible board, and includes a base material 213, a wiring layer 214 provided on the base material 213, and a wiring layer. A plating layer 215 </ b> A provided on 214, and a protective layer 216 provided on wiring layer 214.

  The plating layer 215 </ b> A is formed on the wiring layer 214 by plating, and is provided only on the terminal portion 217 connected to the terminal portion 251 of the circuit board 250. That is, the plating layer 215A is formed only in a region that is not covered by the protective layer 216.

  The material of such a plating layer 215A is not particularly limited as long as it is highly conductive and can be connected to the terminal portion 251 of the circuit board 250 and does not impair the flexibility of the wiring board 212A. The plating layer 215A preferably has higher corrosion resistance than the material of the wiring layer 214 with respect to the solvent contained in the ink. As the material of the plating layer 215A, for example, gold (Au), tin (Sn), platinum (Pt), or the like can be used. The plated layer 215A may be a single layer made of at least one material selected from the above materials, or may be a laminate of a plurality of layers. Further, the plating layer 215A may be formed directly on the wiring layer 214, or an adhesion layer such as nickel may be provided. Incidentally, an adhesion layer such as nickel can also be formed by plating. In addition, when tin is used for the plating layer 215A, whiskers may be formed when stress is applied to the wiring board 212. Therefore, the plating layer 215A is made of a material that does not easily generate whiskers, that is, gold. (Au) or the like is preferably used. The plating layer 215A is preferably made of a material having a lower ionization tendency than the material of the wiring layer 214. Although this will be described in detail later, the plating layer 215A is provided to prevent the solvent contained in the ink from volatilizing and the volatilized solvent from being accumulated on the wiring layer 214 and corroding. By using a material that is less reactive than the wiring layer 214 as 215A, that is, a material that has a low ionization tendency, even if a solvent accumulates on the plating layer 215A, corrosion of the plating layer 215A can be suppressed. . That is, when copper (Cu) is used for the wiring layer 214, it is preferable to use a material that has a smaller ionization tendency than copper (Cu), that is, gold (Au) or the like, as the plating layer 215A.

  The protective layer 216 is made of an insulating material and is formed over at least the wiring layer 214 other than the region where the plating layer 215A is formed. As such a protective layer 216, a solder resist such as a thermosetting epoxy resin can be used as in the first embodiment. Further, the protective layer can be formed in a predetermined shape by applying a resist material coating solution by a screen printing method, for example. In addition, the protective layer 216 is not limited to a solder resist, For example, you may adhere | attached insulating films, such as a polyimide film, with the adhesive agent.

  A region where the plating layer 215 </ b> A is not covered with the protective layer 216 of the wiring layer 214 is a terminal portion 217 connected to the terminal portion 251 of the circuit board 250. In the present embodiment, the terminal part 217 of the wiring board 212 </ b> A and the terminal part 251 of the circuit board 250 are joined by the solder 218. Of course, the method for joining the terminal portion 217 of the wiring board 212A and the terminal portion 251 of the circuit board 250 is not particularly limited to this, and anisotropic conductive adhesive (ACP, ACF), non-conductive adhesive (NCP) , NCF) or the like may be used. Note that the terminal portion 217 of the wiring board 212A and the terminal portion 251 of the circuit board 250 are preferably subjected to heat treatment regardless of which method is used.

  In addition, the plating layer 215A between the wiring board 212A and the circuit board 250, in which the protective layer 216 is not formed and is not joined to the terminal portion 251 of the circuit board 250, is formed by the sealing material 252. Covered. That is, the sealing material 252 is provided on the plating layer 215A other than the region joined to the terminal part 251 of the circuit board 250 in the terminal part 217 provided with the plating layer 215A. In the present embodiment, the wiring board 212 </ b> A (base material 213, protective layer 216, etc.) and the circuit board 250 are bonded by the sealing material 252. Such a sealing material 252 is preferably a material that is less permeable to the solvent contained in the ink than the protective layer 216, and for example, an epoxy adhesive or the like can be used. That is, the same material as the protective layer 216 can be used as the sealing material 252, but the sealing material 252 preferably has a higher crosslink density than the protective layer 216. In other words, the wiring board 212 includes a portion where flexibility is required and a portion where flexibility is not so required, such as the terminal portion 217. Since the protective layer 216 is provided in a portion where flexibility is required, it is preferable to use a material having a low crosslink density. However, if the crosslink density is low, components contained in the ink are easily transmitted. On the other hand, since the sealing material 252 is provided in the vicinity of the terminal portion 217 where flexibility is not required so much, a material having a higher crosslinking density than the protective layer 216 can be used. It becomes difficult to penetrate the components.

  Further, the same sealing material 253 as the sealing material 252 is formed to cover the end surface of the wiring layer 214. That is, when the end surface of the wiring layer 214 is not covered with the plating layer 215, the end surface of the wiring layer 214 is covered with the sealing material 253 because corrosion occurs due to the accumulation of the solvent on the end surface of the wiring layer 214. Thus, corrosion of the end face of the wiring layer 214 can be suppressed.

  By providing the sealing material 252 in this way, it is possible to suppress accumulation of the solvent contained in the solvent volatilized in the altered plating layer 215A in the terminal portion 217 of the wiring board 212A. Therefore, it is possible to prevent the plating layer 215A having deteriorated in the terminal portion 217 of the wiring board 212A from being corroded by the solvent.

  That is, when heated at the time of joining the terminal portion 217 of the wiring board 212A and the terminal portion 251 of the circuit board 250, the plating layer 215A of the wiring board 212A is altered. Specifically, a metal diffusion phenomenon occurs between the plating layer 215 </ b> A of the wiring board 212 </ b> A and the terminal portion 251 of the circuit board 250. When the plating layer 215A is altered in this way, the corrosion resistance of the plating layer 215A to the solvent is lowered. Therefore, when the volatilized solvent comes into contact with the terminal portion 217 where the plating layer 215A is altered, the altered plating layer 215A may be corroded. There is. Note that, when heated at the time of bonding between the terminal portion 217 of the wiring board 212A and the terminal portion 251 of the circuit board 250, the diffusion phenomenon between metals is promoted, and solder bonding, anisotropic conductive adhesive, and Even bonding using a non-conductive adhesive is heated because of reliability and shortening of the curing time. Of course, the diffusion phenomenon between the metals occurs even at room temperature that is not heated, and the plating layer 215A is altered.

  In the present embodiment, the plating layer 215A that has deteriorated at the joint portion with the terminal portion 251 of the circuit board 250 is covered with the sealing material 252 so that the plating layer 215A can be prevented from being corroded by the solvent.

  Further, the portion of the end surface of the wiring layer 214 that is not covered with the plating layer 215A is covered with the sealing material 253, so that the volatilized solvent can be suppressed from being accumulated on the end surface of the wiring layer 214. End surface corrosion can be suppressed.

  Furthermore, in the present embodiment, since the wiring board 212A and the circuit board 250 are bonded together by the sealing material 252, the bonding strength between the wiring board 212A and the circuit board 250 is improved. Therefore, the electrical bonding strength between the terminal portion 217 of the wiring board 212A and the terminal portion 251 of the circuit board 250 is also improved, and problems such as disconnection can be suppressed.

(Other embodiments)
As mentioned above, although each embodiment of this invention was described, the basic composition of this invention is not limited to what was mentioned above.

  For example, in the first and second embodiments described above, the sealing members 252 and 253 are provided in the terminal portion 217 to be joined to the terminal portion 251 of the circuit board 250 of the wiring boards 212 and 212A. Alternatively, a sealing material may be provided in a terminal portion (not shown) of the external wiring board 260 bonded to the circuit board 250 in the same manner. Further, for the wiring (not shown) of the external wiring board 260, if a plating layer similar to the plating layer 215 of the wiring board 212 of the first embodiment is provided, corrosion of the wiring of the external wiring board 260 is suppressed. Can do. Furthermore, if the sealing members 252 and 253 of Embodiments 1 and 2 described above are provided in the terminal portions on the pressure generating means side (not shown) to which the wiring boards 212 and 212A of the head body 210 are connected, Corrosion due to the solvent can be suppressed.

  In the first and second embodiments described above, the sealing material 253 is provided on the end surface of the wiring layer 214. However, since the wiring layer 214 is thin and the area of the end surface is small, the sealing material 253 that covers the end surface is used. Even if it is not provided, it is considered that the influence of corrosion is small. In addition to the end face of the wiring layer 214, if the region not covered by the plating layer 215 of the wiring layer 214, for example, the side surface of the wiring layer 214 is not covered by the plating layers 215 and 215A, the wiring layer A sealing material 253 may be provided on the side surface of 214.

  In the first embodiment described above, the plating layer 215 is provided between the wiring layer 214 and the protective layer 216. However, the plating layer is formed so as to cover the protective layer 216 with respect to the wiring layer 214 covered with the protective layer 216. 215 may be provided. However, as in the first embodiment described above, when the plating layer 215 is provided between the wiring layer 214 and the protective layer 216, the area required for the plating layer 215 can be reduced, and the manufacturing cost can be reduced.

  Further, the ink jet recording head 200 of each of the above-described embodiments is mounted on an ink jet recording apparatus that is an example of a liquid ejecting apparatus. Here, the ink jet recording apparatus of this embodiment will be described. FIG. 6 is a schematic perspective view illustrating an ink jet recording apparatus which is an example of a liquid ejecting apparatus according to an embodiment of the invention.

  As shown in FIG. 6, the ink jet recording apparatus I includes a carriage 3 on which an ink jet recording head 200 is mounted. The carriage 3 is provided on a carriage shaft 5 attached to the apparatus main body 4 so as to be movable in the axial direction.

  Then, the driving force of the driving motor 6 is transmitted to the carriage 3 via a plurality of gears and timing belt 7 (not shown), so that the carriage 3 on which the ink jet recording head 200 is mounted is moved along the carriage shaft 5. . On the other hand, the apparatus main body 4 is provided with a conveyance roller 8 as a conveyance unit, and a recording sheet S which is a recording medium such as paper is conveyed by, for example, the conveyance roller 8 as a conveyance unit. Note that the conveyance means for conveying the recording sheet S is not limited to the conveyance roller, and may be a belt, a drum, or the like.

  Further, the ink jet recording apparatus I is provided with a liquid storing means 2 such as an ink tank fixed to the apparatus main body 4 and storing ink therein. A supply pipe 2 a that supplies ink to the ink jet recording head 200 and a recovery pipe 2 b that recovers ink from the ink jet recording head 200 are connected to the liquid storage unit 2.

  The supply pipe 2a and the recovery pipe 2b are made of a tubular member such as a flexible tube, and are respectively provided with a supply path for supplying ink and a recovery path for recovering ink. Then, one end of the supply pipe 2a is connected to the supply flow path 410 of the ink jet recording head 200, and one end of the recovery pipe 2b is connected to the recovery flow path 420, whereby the ink of the liquid storage means 2 is discharged to the ink jet recording head. The ink from the ink jet recording head 200 is collected in the liquid storage unit 2 while being supplied to the ink jet recording head 200.

  Although not particularly illustrated, a pressure feeding means such as a pressure pump or a suction pump is provided in the middle of the supply pipe 2a or the recovery pipe 2b, and the ink is stored in the liquid storage means 2 by the pressure feeding of the pressure feeding means. And the ink jet recording head 200.

  In the example illustrated in FIG. 6, the ink jet recording head 200 is mounted on the carriage 3 and moves in the main scanning direction. However, the present invention is not particularly limited thereto. For example, the ink jet recording head 200 is fixed. Thus, the present invention can also be applied to a so-called line type recording apparatus that performs printing only by moving a recording sheet S such as paper in the sub-scanning direction.

  Further, in the above-described example, the ink jet recording head 200 that supplies ink to the ink jet recording head 200 from the liquid storing means 2 and collects ink to the liquid storing means 2 is exemplified, but the invention is not particularly limited thereto. The present invention can also be applied to an ink jet recording head that simply supplies ink from the liquid storage means 2 to the ink jet recording head 200.

  Further, in the above-described example, the liquid storage means 2 is fixed to the apparatus main body 4 and ink is supplied to the ink jet recording head 200 via the supply pipe 2a. The liquid storage means such as the above may be mounted on the carriage 3 so that the liquid storage means moves along the carriage shaft 5 together with the ink jet recording head 200. Further, the liquid storage means may not be mounted on the ink jet recording apparatus I.

  In the above embodiment, an ink jet recording head has been described as an example of a liquid ejecting head. However, the present invention is widely intended for a liquid ejecting head, and is a liquid that ejects liquid other than ink. Of course, the present invention can also be applied to an ejection head. Other liquid ejecting heads include, for example, various recording heads used in image recording apparatuses such as printers, color material ejecting heads used in the manufacture of color filters such as liquid crystal displays, organic EL displays, and FEDs (field emission displays). Examples thereof include an electrode material ejection head used for electrode formation, a bioorganic matter ejection head used for biochip production, and the like.

  I ink jet recording apparatus (liquid ejecting apparatus), 2 liquid storing means, 200 ink jet recording head (liquid ejecting head), 210 head main body, 211 nozzle opening, 211a liquid ejecting surface, 212, 212A wiring board, 213 base material, 214 Wiring layer, 215, 215A Plating layer, 216 Protective layer, 217 Terminal section, 220 Channel member, 250 Circuit board, 251 Terminal section, 260 External wiring board, 270 Cover head, 400 Liquid channel

Claims (6)

A liquid ejecting head for ejecting a liquid containing a solvent,
A flexible substrate, and a rigid substrate bonded to the flexible substrate,
The flexible substrate is
A substrate;
A wiring layer provided on the substrate;
A plating layer provided over the entire surface of the wiring layer and formed of a material having higher corrosion resistance to the solvent than the wiring layer;
An insulating protective layer provided on the plating layer,
The liquid ejecting head, wherein the rigid substrate is bonded to the plating layer on which the protective layer is not provided.   The plating layer between the wiring layer and the rigid substrate, in which the protective layer is not formed, and the region that is not bonded to the rigid substrate has a solvent permeability to the protective layer. The liquid ejecting head according to claim 1, wherein the liquid ejecting head is covered with a sealing material made of a low material. A liquid ejecting head for ejecting a liquid containing a solvent,
A flexible substrate, and a rigid substrate bonded to the flexible substrate,
The flexible substrate is
A substrate;
A wiring layer provided on the substrate;
A plated layer provided in a region bonded to at least the rigid substrate on the wiring layer;
An insulating protective layer provided on the wiring layer,
The plating layer between the wiring layer and the rigid substrate, wherein the protective layer is not provided and a region not bonded to the rigid substrate is covered with a sealing material. Liquid ejecting head.   The liquid ejecting head according to claim 2, wherein the sealing material is an epoxy adhesive.   The liquid jet head according to claim 2, wherein an end surface of the wiring layer is covered with the sealing material.   A liquid ejecting apparatus comprising the liquid ejecting head according to claim 1.

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