JP5341688B2 - Liquid discharge head and manufacturing method thereof - Google Patents

Description

  The present invention relates to a liquid discharge head that discharges liquid to perform recording on a recording medium, and a manufacturing method thereof.

  A liquid discharge head (hereinafter also referred to as a head) provided by bonding a liquid discharge head substrate (hereinafter also referred to as a head substrate) to a support substrate is mounted on a liquid discharge device, and the discharge port of the liquid discharge head A recording operation is performed on the recording medium by discharging a liquid such as ink from the recording medium.

  In order to make such electrical connection between the head substrate and the support substrate, Patent Document 1 discloses a configuration in which a through electrode penetrating from the front surface to the back surface of the silicon substrate is provided. The head disclosed in Patent Document 1 is shown in FIG. The recording element substrate H1100 having a through electrode and the holding substrate H1200 are mounted by being electrically connected via an electric bump H1105 used as an electrical connection portion.

JP 2007-326240 A

  The head substrate is provided by simultaneously forming and cutting a plurality of head substrates on a silicon substrate or the like using a semiconductor manufacturing technique. For this reason, as the size of each head substrate increases, the number of head substrates that can be formed from a single silicon substrate decreases, resulting in increased manufacturing costs. Therefore, it is required to reduce the area of the head substrate. ing. Also, from the viewpoint of achieving a reduction in the size of a liquid discharge apparatus that mounts a liquid discharge head, there is a demand for downsizing the head substrate.

  However, in the configuration of the head of Patent Document 1, a certain distance is provided between the ink supply port and the electric bump H1105 in order to prevent ink penetration, and the sealant H1317 that blocks the ink around the electric bump H1105. Is provided. If this distance is shortened, ink may permeate and the electric bumps H1105 may corrode. Therefore, it is difficult to reduce the area of the head substrate by shortening the distance.

  Accordingly, the present invention provides a liquid ejection head that can achieve both the prevention of ink soaking into the electrical connection portion and the reduction of the area of the head substrate in a liquid ejection head using the liquid ejection head substrate. It is intended to provide.

  The liquid discharge head according to the present invention includes a first surface provided with a plurality of elements that generate energy used for discharging liquid, and a surface opposite to the first surface provided with a recess. A substrate having a second surface, a liquid supply port penetrating between the first surface and the second surface, and a plurality of the elements electrically connected to the first surface of the substrate. A liquid discharge head having a plurality of electrodes penetrating between the surface of the recess and the inside of the recess, and a conductive layer electrically connected in common to the plurality of electrodes and provided on the inside A substrate for supporting the liquid discharge head and the substrate for the liquid discharge head from the second surface side, and a convex portion provided on the inside of the concave portion, and provided on the convex portion and electrically connected to the conductive layer A connecting member, and an opening that communicates with the supply port and supplies liquid to the supply port. A support substrate, and a resin covering the conductive layer and the connection member between the support substrate and the liquid discharge head substrate from the inside of the recess to the second surface. The member which becomes is characterized by the above-mentioned.

  Even if the head substrate is reduced, the head substrate is provided with a concave portion and the support substrate is provided with a convex portion, and a connection member is provided on the convex portion for electrical connection, and the gap between the concave portion and the convex portion is sealed. The distance between the member and the supply port can be a distance that can prevent the ink from penetrating into the connection portion.

  As a result, it is possible to provide a liquid ejection head that can achieve both the prevention of ink soaking into the connection member and the reduction of the liquid ejection head substrate.

It is a cross-sectional schematic diagram of a conventional head. It is a perspective view of a head using the present invention. It is a top view of the substrate for heads of an example of the present invention. It is sectional drawing of the board | substrate for heads of an example of this invention. It is sectional drawing of the board | substrate for heads of an example of this invention. 6 is a cross-sectional view showing a method for manufacturing the head substrate shown in Example 1. FIG. FIG. 6 is a cross-sectional view showing a method for manufacturing the support substrate shown in Example 1. 6 is a cross-sectional view illustrating a method for manufacturing the head shown in Embodiment 1. FIG. 6 is a cross-sectional view illustrating a method for manufacturing a support substrate shown in Example 2. FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 2 is a top view of a liquid discharge head 40 (hereinafter also referred to as a head) that can be mounted on a liquid recording apparatus using the present invention. A liquid discharge head substrate 41 (hereinafter also referred to as a head substrate) is electrically connected to a contact pad 44 connected to a liquid recording apparatus by a flexible film wiring substrate 43 connected to a terminal provided on the support substrate. The head substrate 41 is supported by the head 40 by being bonded to the support substrate. Here, the head 40 is an example of a head integrated with an ink tank, but may be a separate type separated from the ink tank.

  FIG. 3A shows three supply port rows in which a plurality of ink supply ports 10 used for supplying one type of ink are arranged, and three types of ink (for example, yellow, magenta, cyan). 1 shows a head substrate 41 that can be used for a head that uses). FIG. 3B shows a head substrate 41 that has one supply port array composed of a plurality of ink supply ports 10 that supply one type of ink and uses one type of ink.

  In the head substrate 41, the heating element 1 used as an element that generates energy for ejecting ink, the individual power wiring 36 that supplies power to the heating element 1, and the power common to the plurality of heating elements 1 are provided. Power wiring 13 used as a conductive layer to be supplied is provided. An element array configured by arranging a plurality of heating elements 1 is provided on both sides of the supply port array along the supply port array. Further, the head substrate 41 is provided with a drive circuit 11 used as a switching element that outputs a signal for selecting the heating element 1. The drive circuit 11 is provided on the side opposite to the supply port array along the element array.

  FIG. 4A is an example of a schematic cross-sectional view in the AA ′ direction of FIG. 3A, in which a plurality of supply port arrays are provided, and a plurality of heating elements 1 are provided in a region between adjacent supply port arrays. The structure which provided the two electric power wiring 13 connected to is shown. FIG. 4B shows an example of a schematic cross-sectional view in the C-C ′ direction of FIG. 3A of the head having one supply port array.

  A supply port array composed of a plurality of supply ports 10 for supplying ink to the heating element 1 provided on the head substrate 41 is a surface opposite to the first surface of the substrate on which the heating element 1 is provided. The second concave portion 8 and the ink through hole 9 of the supply port array provided on the surface of The ink supplied from the opening 30 of the support substrate through the supply port 10 is ejected from the ejection port 4 by the energy generated in the heating element 1, thereby performing a recording operation on the recording medium. The discharge port 4 and the flow path communicating with the discharge port are formed by a flow path forming member 3 made of resin. A protective layer 12 is provided on the top of the heating element 1 to protect it from ink, and a flow path forming member 3 is provided above the protective layer 12.

  The individual power wiring 36 that is connected to the heating element 1 and supplies current to the heating element 1 has a common GNDH inside the first recess 7 provided on the second surface of the substrate 2 through the through electrode 5. It is connected to the power wiring 13 used for wiring and VH wiring. The power wiring 13 is provided along the element row, and one power wiring 13 is connected to only one of the GNDH wiring and the VH wiring. When providing both the GNDH wiring and the VH wiring inside the first recess 7, it is necessary to provide two power wirings 13.

  A third surface is provided inside the first recess 7 so that the thickness of the substrate is thinner than the thickness of the second surface and the first surface in the direction perpendicular to the surface of the substrate. . The power wiring 13 is provided on the convex portion 22 having a thickness larger than the mounting surface 21 of the support substrate 20 via the bumps 6 used as connection members, and is electrically connected to the electrical connection terminals 14 used as terminals. . Further, between the first concave portion 7 and the convex portion 22 provided with the bump 6, the electrical connection terminal 14, and the power wiring 13, a member made of resin or the like is used as the sealing member 24 and the bump 6 and the electrical connection terminal 14. And are sealed so as to cover the power wiring 13.

  FIG. 5 is an example of a schematic cross-sectional view of the head in the B-B ′ direction of FIG. 3. A plurality of through-electrodes 5 connected to the individual power wirings 36 provided for each of the plurality of heating elements 1 are provided along the direction of the element rows. The plurality of through electrodes 5 are connected to the power wiring 13 inside the recess 7 of the substrate 2.

  FIG. 5A shows a configuration in which the bump 6 is provided on the entire surface of the power wiring 13 and the electrical connection terminal 14. However, if electrical connection is possible, 2 as shown in FIG. Only one bump 6 can be provided. In this way, the concave portion of the substrate and the convex portion of the support substrate 20 are electrically connected, and the periphery of the bump is covered with a member made of a resin made of an amine curable epoxy resin composition or the like as the sealing member 24. Sealing is performed. The sealing member 24 may be sealed using a plurality of materials as well as one kind of sealing material. An adhesive material can also be used as the sealing material.

  As described above, the recesses of the substrate and the convex portions of the support substrate 20 are electrically connected, and the gaps between the concave portions and the convex portions are sealed. The distance can be a distance that can prevent the ink from penetrating into the bump.

Example 1
Next, an example of the present invention will be specifically described with reference to a manufacturing method. In the present embodiment, a configuration in which a first supply port row and a second supply port row adjacent to each other are provided will be described. A region between the first supply port row and the second supply port row is provided along the first supply port row, and the first element row corresponding to the first supply port row, A second element row corresponding to the second supply port is provided along the second supply port row.

  FIG. 6 shows a manufacturing method of the head substrate 41 according to the schematic cross-sectional view of FIG. FIG. 7 shows a method for manufacturing the head support substrate 20 of this embodiment. FIG. 8 shows a manufacturing method for mounting the head substrate 41 and the support substrate 20.

  A heating element 1 and a driving circuit 11 used as an element for generating energy were formed on a first surface of a substrate 2 (first substrate) containing silicon having a thickness of 625 nm as a main component (FIG. 6A). Further, a protective layer 12 is provided on the upper side of the heating element 1 and the drive circuit 11 in the direction perpendicular to the surface of the substrate. Next, a cationic polymerization type epoxy resin or the like used as the flow path forming member 3 is applied to the substrate 2 by using a spin coat method or the like, and an ejection port 4 is formed by performing exposure and development using a photolithography method (FIG. 6). (B)).

  A mask made of a resist or the like in which a region located in the first recess 7 and the second recess 8 is opened on the second surface opposite to the surface on which the heating element 1 of the substrate 2 is provided by using a photolithography method. Was provided. Further, a part of the substrate 2 was subjected to crystal anisotropic etching using tetramethylammonium hydroxide (hereinafter referred to as TMAH) as an etchant to expose the third surface having a depth of 425 μm. Thereby, the 1st recessed part 7 and the 2nd recessed part 8 were provided. As the etchant, a strong alkaline solution such as KOH or NaOH can be used in addition to TMAH. It is known that the etching rate of the silicon crystal orientation <111> plane with respect to a strong alkali etchant such as TMAH is significantly slower than the silicon crystal orientation <100>. Therefore, when the second surface is a silicon crystal orientation <100> plane, the side surfaces of the first recess 7 and the second recess 8 are etched so as to be the <111> plane. An inclination of about 54.7 degrees can be provided. Thereby, the 1st recessed part 7 and the 2nd recessed part continued from the 2nd surface, and the 1st slope provided from the 2nd surface to the position of the 3rd surface was provided.

  The opening width of the substrate 2 in the first recess 7 provided with the power wiring 13 is set to 1000 μm, and the opening width of the substrate 2 in the second recess 8 of the supply port 10 is set to 800 μm. Thereafter, the resist mask was stripped using a stripping solution or the like to provide the substrate 2 in FIG.

  Next, a mask for forming a through hole in which the through electrode 5 is to be formed is formed by using a photoresist method or the like, and the substrate 2 is etched from the first recess 7 by dry etching or the like such as a Bosch process. A through hole for providing the through electrode 5 was provided. Thereafter, the resist mask was stripped using a stripping solution or the like.

  Next, an insulating layer (not shown) for ensuring the insulation between the through electrode 5 and the substrate 2 was formed on the entire surface by a CVD method using a resin such as silicon oxide, silicon nitride, or parylene. Thereafter, a region other than the region provided with the through holes was opened by using a photolithography technique, and unnecessary insulating layers were removed by a technique such as RIE. Furthermore, a metal film was formed in the through hole by a vapor deposition method, and patterning was performed using a photolithography technique or the like, thereby forming the through electrode 5 that can be electrically connected to the individual power wiring 36. The through electrode 5 was filled with a conductive material by electrolytic plating after depositing a metal film in order to obtain a sufficiently low resistance. Thereby, it was possible to provide a thick film, and it was possible to provide the through electrode 5 having a lower resistance than the film formation by metal film deposition alone (FIG. 6D).

  Next, titanium tungsten, which is a refractory metal material, was formed as a diffusion prevention layer (not shown) on the surface of the substrate 2 provided with the first recess 7 and the second recess 8. Subsequently, a plating conductor layer (not shown) excellent as a wiring layer was formed on the entire surface by vacuum film formation or the like. In order to improve the adhesion between the diffusion prevention layer and the plating conductor gold layer, it is desirable to form the plating conductor metal after removing the oxide film from the diffusion prevention film.

  Further, a photoresist was applied to the entire surface of the gold layer of the plating conductor by a method such as spin coating, slit coating, or spray coating. At this time, a photoresist was applied so as to be thicker than a desired wiring thickness. Furthermore, in order to remove the photoresist so as to expose the gold layer of the plating conductor in the part where the wiring is to be formed, resist exposure and development were performed by a photolithography method to form a mask serving as a mold material for plating.

  Using this mask, a predetermined current was passed through gold as a plating conductor in an electrolytic bath of gold sulfite by electrolytic plating to form power wirings 13 connected to the plurality of through electrodes 5. Thereafter, the resist mask was stripped using a stripping solution or the like to provide the head substrate of FIG.

  Thereafter, the silicon substrate 2 is etched by 200 μm using dry etching such as Bosch process, the ink through hole 9 is provided, and the supply port 10 including the ink through hole 9 and the second recess 8 is provided (FIG. 6F). )).

  In the present embodiment, the ink through hole 9 and the through hole of the through electrode 5 are formed in separate steps, but can be formed simultaneously. At that time, a metal film to be a conductive film is also formed on the ink through hole 9 by vapor deposition, and is patterned so as to allow electrical contact only to the through hole.

  A plurality of substrates for heads were provided by forming a plurality of substrates 2 at the same time by the above process and cutting them with a dicing saw or the like.

  Next, a method for manufacturing the head support substrate will be described. A resist mask was provided on the substrate (third substrate) whose main component is silicon thinner than the depth of the first recess so as to have an opening width of about 900 μm. Further, similarly to the first substrate, a strong alkali such as TMAH was used as an etchant, and portions other than the portion serving as the convex member were removed by crystal anisotropic etching. The surface of the third substrate used at this time is also the second inclined surface having the same inclination angle of about 54.7 degrees as the first inclined surface with respect to the surface of the substrate by making the crystal orientation <100> plane of silicon. A convex member can be provided.

  Further, a support substrate having a convex portion 22 shown in FIG. 6B by bonding a convex portion member to a mounting surface 21 of a substrate (second substrate) made of alumina or the like having an opening 30 for supplying ink. 20 was provided. Furthermore, the bumps 6 made of a conductive material such as gold are provided on the convex portions 22 of the support substrate 20.

  Next, the first concave portion having the first slope of the head substrate 41 shown in FIG. 6F and the convex portion 22 having the second slope of the support substrate 20 shown in FIG. As shown in FIG. Further, the opening 30 of the support substrate 20 and the supply port 10 of the head substrate 41 are provided so as to coincide with each other. Thereby, the power wiring 13 of the head substrate 41 and the bump 6 of the support substrate 20 can be electrically connected, and ink can be supplied from the opening 30 of the support substrate 20 to the supply port of the head substrate 41. It was.

  Thereafter, a sealing member 24 made of a resin made of an amine curable epoxy resin composition is provided in the gap between the first concave portion 7 and the convex portion 22 provided with the bump 6, the electrical connection terminal 14, and the power wiring 13. Filled and covered to seal as shown in FIG.

  As described above, the first concave portion 7 is provided in the head substrate 41 and the convex portion 22 is provided in the support substrate 20, and electrical connection is performed at the portion, and the inclined surface between the first concave portion and the convex portion is sealed Sealed with member 24. Thereby, even if the head substrate is further reduced, the distance between the bump 6 and the supply port 10 can be set to a distance that can prevent the ink from penetrating into the bump 6.

  The space between the first inclined surface of the first recess 7 and the second inclined surface of the convex portion 22 which is substantially parallel is sealed with a sealing member 24 made of resin or the like, thereby reliably covering and sealing. And corrosion due to ink could be more effectively prevented. As a result, even if the head substrate is further reduced, it is possible to provide a liquid ejection head that can prevent ink from penetrating into the bumps 6 and the power wirings 13.

(Example 2)
In the present embodiment, a method for manufacturing the support substrate 20 different from that in the first embodiment will be described. The head substrate was provided using the manufacturing method of Example 1.

  The support substrate 20 is made of polysulfone resin having excellent heat resistance and chemical resistance, and has a width of 900 μm in the direction perpendicular to the element array, a height of 425 μm, and an opening 30 for supplying ink. Injection molding was performed so as to have (FIG. 9A). In addition, any resin that can be injection-molded having heat resistance and chemical resistance can be used as the support substrate 20 in the same manner. For example, polyether sulfone resin, polyphenylene ether resin, polyphenylene oxide resin, polypropylene resin, etc. Can also be used.

  At this time, the convex portion 22 was provided so as to have a second inclined surface having the same inclination angle as the first concave portion 7 of the head substrate.

  Next, bumps 6 made of a conductive material such as gold and electrical connection terminals 14 were formed on the protrusions 22 of the support substrate 20 (FIG. 9B).

  The head substrate 41 shown in FIG. 6 (f) and the support substrate 20 shown in FIG. 9 (b) were combined as shown in FIG. 7 to make electrical connection. The opening 30 of the support substrate 20 and the supply port 10 of the head substrate 41 were bonded so as to coincide with each other. As a result, the ink could be supplied from the support substrate 20 to the head substrate 41.

  Thereafter, a sealing member 24 made of an amine curable epoxy resin composition is filled in a gap of about 50 μm between the first concave portion 7 and the convex portion 22 provided with the bump 6, the electrical connection terminal 14, and the power wiring 13. As a result, sealing was performed as shown in FIG.

  As described above, the first concave portion 7 is provided in the head substrate 41 and the convex portion 22 is provided in the support substrate 20, and electrical connection is performed at the portion, and the inclined surface between the first concave portion and the convex portion is sealed. Sealed with member 24. Thereby, even if the head substrate is further reduced, the distance between the bump 6 and the supply port 10 can be set to a distance that can prevent the ink from penetrating into the bump 6.

  Further, the support substrate 20 is provided so as to have an inclined surface having substantially the same inclination angle as the first inclined surface by injection molding with a resin member so as to correspond to the first recess. As described above, the gap between the first inclined surface of the first recess 7 and the second inclined surface of the substantially parallel convex portion 22 is sealed with the sealing member 24 made of resin or the like, thereby ensuring more certainty. The bump 6 and the power wiring 13 can be covered and sealed. As a result, it was possible to provide a liquid discharge head capable of preventing ink penetration even when the head substrate is further reduced.

  Further, by using the injection molding technique as shown in the present embodiment, it is possible to reduce the convex etching process and the alumina substrate bonding process as shown in the first embodiment, thereby reducing the manufacturing cost. I was able to.

DESCRIPTION OF SYMBOLS 1 Element 2 Board | substrate 5 Electrode 7 Concave part 10 Supply port 13 Power wiring 14 Terminal 20 Supporting substrate 22 Convex part 24 Sealing member 40 Liquid discharge head 41 Liquid discharge head substrate

Claims (8)

A first surface provided with a plurality of elements for generating energy used for discharging liquid, a second surface opposite to the first surface, provided with a recess, and the first surface A substrate having a liquid supply port penetrating between the first surface and the second surface; and electrically connected to the plurality of elements; and the first surface of the substrate and the inside of the recess A liquid discharge head substrate having a plurality of electrodes penetrating between and a conductive layer commonly connected to the plurality of electrodes and provided on the inside;
Supporting the liquid discharge head substrate from the second surface side, a convex portion provided inside the concave portion, and a connecting member provided on the convex portion and electrically connected to the conductive layer; A support substrate in communication with the supply port, and an opening for supplying a liquid to the supply port;
Have
A member made of a resin that covers the conductive layer and the connection member is provided between the liquid discharge head substrate and the support substrate from the inside of the recess to the second surface. Liquid discharge head.   2. The liquid discharge head according to claim 1, wherein a plurality of the supply ports are provided, and the plurality of supply ports are arranged so that a supply port array is provided on the substrate.   3. The element row configured by arranging a plurality of the elements is provided on both sides of the supply port of the first surface so as to sandwich the supply port row. The liquid discharge head described. The recess has a first slope that is continuous with the second surface and is provided from the second surface to a position between the first surface and the second surface;
The convex portion has a second slope substantially parallel to the first slope,
4. The liquid ejection head according to claim 1, wherein a member made of the resin is provided between the first inclined surface and the second inclined surface. 5. A first surface provided with a plurality of elements for generating energy used for discharging liquid, a second surface opposite to the first surface, provided with a recess, and the first surface And a liquid supply port penetrating between the second surface and the second surface; and a plurality of the elements electrically connected to the first surface of the substrate and the recess A liquid discharge head substrate comprising: a plurality of electrodes penetrating between the plurality of electrodes; and a conductive layer electrically connected in common to the plurality of electrodes and provided on the inside. And a process of
A support substrate having a convex portion provided with a connecting member that can be electrically connected to the conductive layer, and an opening for supplying a liquid to the supply port; and the convex portion is the liquid ejection head substrate. Providing the support substrate so that the opening and the supply port communicate with each other at an inner position;
Electrically connecting the conductive layer and the connecting member;
Providing a member made of resin so as to cover the conductive layer and the connection member between the liquid discharge head substrate and the support substrate from the inside of the recess to the second surface;
A method of manufacturing a liquid discharge head, comprising: Providing the support substrate comprises:
Providing a second substrate having the opening;
Adhering the convex part member for forming the convex part and the second substrate;
Providing the connection member on the convex portion;
The method of manufacturing a liquid discharge head according to claim 5, wherein:   The first substrate is formed of silicon, the recess is obtained by removing a part of the first substrate by crystal anisotropic etching, and the convex member is a third of silicon. The method of manufacturing a liquid discharge head according to claim 6, wherein the substrate is obtained by performing anisotropic etching on the substrate to remove a portion other than the portion serving as the convex member. Providing the support substrate comprises:
Forming a member made of a resin having the opening and the convex portion by injection molding;
Providing the connection member on the convex portion;
The method of manufacturing a liquid discharge head according to claim 5, comprising:

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