JP2006035853A - Manufacturing method for inkjet recording head, inkjet recording head, substrate for recording head, and inkjet cartridge - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method or the like for a recording head which suppresses ejection defects due to a foreign substance such as dust generated at the time of manufacturing or using of the recording head. <P>SOLUTION: A silicon oxide film 16 is formed as a thermal storage layer on a silicon substrate 1. Then a plurality of through holes 17 which communicate with an ink supply port 8 are formed on the oxide film 16. Moreover, a heating element 2 is formed on the oxide film 16, and at the same time a silicon nitride film 18 is formed as a protecting layer on the oxide film 16. Next, a coating resin layer 5 as a passage constituting member is formed on the protecting layer, and also the ink supply port 8 is formed in the substrate 1 from the substrate rear face side. A filter consisting of the plurality of through holes is formed by removing a part of the silicon nitride film 18 with the silicon oxide film 16 being made a mask. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for manufacturing an ink jet recording head that performs recording by discharging droplets, an ink jet recording head, a substrate for the recording head, and an ink jet cartridge. Specifically, the method for manufacturing an ink jet recording head including a filter, and ink jet recording The present invention relates to a head, a recording head substrate, and an ink jet cartridge.

  In recent years, in order to reduce the size and increase the density of an ink jet recording head, a method has been proposed in which an electric control circuit for driving an ink discharge pressure generating element is built in a substrate using a semiconductor manufacturing technique. In such an ink jet recording head, in order to supply ink to a plurality of ejection openings, each substrate (ejection opening) communicates with a common ink supply opening by penetrating the substrate from the back side of the substrate. Ink is supplied from the supply port to each nozzle. For such a recording head, a method disclosed in Patent Document 1 is known as a manufacturing method for making the distance between the ink discharge pressure generating element for discharging ink from the discharge port and the discharge port with extremely high accuracy. Yes. In addition, when a silicon substrate is used as the substrate of such an ink jet recording head, it is possible to form an ink supply port using an anisotropic etching technique as disclosed in Patent Document 2. .

  One of the reliability required for the ink jet recording head is to suppress the entry of dust and foreign matter into the nozzle. Possible causes are that dust and foreign matter are mixed in the nozzle during the manufacturing process of the ink jet recording head, and that dust and foreign matter are sent together with ink and enter the nozzle. As a countermeasure against this problem, it is known to provide a filter in the ink jet recording head.

  For example, in Patent Document 3, in a recording head configured by bonding a member that forms an ejection port and a flow path to a silicon substrate provided with an ink supply port, an ink supply port is provided on a surface provided with a heater. It discloses that a resistance material layer for etching is provided, and a plurality of holes are provided in the resistance material layer to form a filter at the same time as forming an ink supply port. Further, Patent Document 4 discloses a configuration in which individual ink supply ports corresponding to each of a plurality of ink ejection chambers are provided.

On the other hand, in Patent Document 5, when forming an ink supply port on a silicon substrate, a membrane filter is used simultaneously with the ink supply port by using side etching on an etching resistant mask on the opposite side of the surface provided with the heater. The provision is disclosed.
US Pat. No. 5,478,606 US Pat. No. 6,139,761 US Pat. No. 6,264,309 US Pat. No. 6,543,884 JP 2000-94700 A

  However, in Patent Document 3 and Patent Document 4, since a member that forms an ejection port and a flow path is bonded to a silicon substrate having an ink supply port, a nozzle is used for the bonding. There is a risk of dust and foreign matter entering the inside. In addition, as disclosed in these documents, the method of forming an ink supply port in a silicon substrate after previously providing a hole to be a filter in a thin film on a silicon substrate, the anisotropic etching disclosed in Patent Document 2 is performed. The ink supply port is formed with a hole in the stop layer. Therefore, when applying the method disclosed in the above document to the method disclosed in Patent Document 1, a soluble resin for forming the flow path is immersed in an etching solution for forming the ink supply port. As a result, the accuracy of the manufactured head and the yield of high-precision head manufacturing may be adversely affected.

On the other hand, in the method of Patent Document 5, an insulating film made of SiO ₂ , SiN or the like is used as an etching resistant mask, but the insulating film (etching resistant mask) exposed on the back side of the silicon substrate is usually sputtered. It is configured as a deposited film formed by chemical vapor deposition (CVD) or chemical vapor deposition, and it is corroded by being exposed to various liquids in the subsequent process, and in the semiconductor manufacturing apparatus during the manufacturing process. Since a minute scratch may be attached when the product is conveyed, it is very difficult to keep the filter made of the insulating film free from defects until the final product is manufactured.

  The present invention has been conceived in order to solve the above-described technical problems, and its purpose is to make the distance between the ink discharge pressure generating element and the discharge port extremely accurate and at the time of manufacturing or using the ink jet recording head. An object of the present invention is to provide an ink jet recording head manufacturing method, a recording head manufactured by the manufacturing method, and an ink jet cartridge that suppress ejection failure due to foreign matters such as dust.

  In order to achieve the above-described object, a method of manufacturing an inkjet head according to the present invention includes a plurality of ejection ports for ejecting ink, a plurality of ink flow paths respectively communicating with the plurality of ejection ports, An ink jet head manufacturing method comprising: an ink supply port for supplying a liquid to an ink flow path, the step of preparing a silicon substrate, and the step of forming a heat storage layer on the first surface of the silicon substrate A step of forming a plurality of through holes for communicating with the ink supply port in the heat storage layer, a step of forming a heating element for discharging ink on the heat storage layer, and the heating element. A step of forming a protective layer on the silicon substrate having a heat storage layer having a plurality of through-holes formed; and a flow that forms the plurality of ejection openings and the plurality of ink flow paths on the protective layer. Form the road component And forming the ink supply port in the silicon substrate by anisotropic etching from the second surface side facing the first surface of the substrate, and partially passing through the protective film. Removing the heat storage layer in which the hole is formed as a mask, and forming a filter by the plurality of through holes.

  According to the above-described ink jet head manufacturing method, when the ink supply port is formed, the protective layer and the heat storage layer prevent communication between the ink flow path and the ink supply port. Therefore, even when the flow path is formed by a resin mold, the resin forming the mold does not come into contact with the etching solution for anisotropic etching. Furthermore, since a filter with a heat storage layer and a protective layer can be formed on the surface of the substrate on which the ink flow path is formed in a state where the ink flow path is formed, it is possible to prevent dust from being mixed during manufacturing due to bonding or the like. There is no need to Further, in the subsequent processes such as dicing and sticking to the chip plate, the filter is not exposed on the surface of the head chip, so that the filter is not damaged by handling or the like. Accordingly, it is possible to provide a method for manufacturing an ink jet recording head that solves the above-described problems and suppresses ejection failures due to foreign matters such as dust generated during the manufacture or use of the ink jet recording head.

  The ink jet recording head of the present invention is an ink jet recording head that performs recording by discharging ink by heat generation of a heat generating element, and supplies a plurality of heat generating elements for discharging ink and the heat generating element. A plurality of ejection openings for ejecting ink corresponding to each of the plurality of heating elements, each of the plurality of ink ejection openings, and the ink supply opening. A plurality of ink flow paths that communicate with each other, and a flow path constituting member for forming a filter, and a filter comprising a heat storage layer and a protective layer provided on the silicon substrate is formed at the ink supply port. It is characterized by that.

  According to the above-described ink jet recording head, it can be easily manufactured by the above-described manufacturing method.

  Furthermore, the present invention also provides a recording head substrate used for the recording head and an ink jet cartridge including the recording head.

  As described above, according to the present invention, a method of manufacturing an ink jet recording head, a recording head manufactured by the manufacturing method, and an ink jet cartridge that suppress ejection failure due to foreign matters such as dust generated during the manufacture and use of the ink jet recording head are provided. Can provide.

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

  FIG. 1A is a schematic diagram showing an ink jet recording head according to an embodiment of the present invention.

  As shown in FIG. 1A, the recording head 50 is configured by forming a plurality of ejection ports 7 for ejecting ink and disposing a coating resin layer 5 functioning as an orifice plate on the silicon substrate 1. Has been. In the silicon substrate 1, ink supply ports 8 for supplying ink to the respective discharge ports 7 are formed as through holes. On both sides of the ink supply port 8, energy generating elements 2 (heating elements) for applying thermal energy to the ink are arranged so as to face the respective discharge ports 7. In addition, an ink flow path 6 is formed between the coating resin layer 5 and the silicon substrate 1, so that ink from the ink supply port 8 is supplied to each ejection port 7.

  The recording head 50 configured as described above is mounted and used in an ink jet recording apparatus (not shown). Specifically, when a predetermined electrical signal generated by a control device (not shown) of the ink jet recording apparatus is input to the energy generation element 2, the energy generation 2 is driven to cause a foaming phenomenon in the ink. Ink is ejected from the ejection port 7 as ink droplets by the energy of the foaming.

  FIG. 1B is a perspective view showing an example of an ink jet cartridge equipped with the ink jet recording head shown in FIG. The ink jet cartridge 300 includes the above-described ink jet recording head 50 and an ink containing portion 200 that contains ink to be supplied to the ink jet recording head 50, and these are integrated.

(First embodiment)
Next, a detailed configuration of the recording head according to the first embodiment of the present invention will be described with reference to FIG.

  The recording head 50 is configured by disposing the coating resin layer 5 on a recording head substrate 30 in which a plurality of layers are stacked with the silicon substrate 1 as a base. That is, the recording head substrate 30 is obtained by removing the coating resin layer 5 from the recording head 50.

On the surface side of the silicon substrate 1, a field oxide film 13, a BPSG (borosilicate glass) film 14, a silicon oxide film 16 made of silicon dioxide, a silicon nitride film 18 made of silicon nitride, and a tantalum film 19 are sequentially laminated. The energy generating element 2 is formed on the silicon nitride film 16. A thermal oxide film (SiO ₂ film) 3 used as a mask when forming the ink supply port 8 is formed on the back side of the substrate. In the recording head 50, the silicon oxide film 16, the BPSG film 14, and the field oxide film 13 are provided as heat storage layers, and the silicon nitride film 18 and the tantalum film 19 are provided as protective layers. It is.

  The function of each of these films is also disclosed in a known document (for example, Japanese Patent Application Laid-Open No. 2003-136492), and detailed description thereof is omitted, but the field oxide film 13 is formed on the silicon substrate 1. The BPSG film 14 and the silicon oxide film 16 function as an interlayer insulating film of the drive circuit, for isolating semiconductor elements of the drive circuit (not shown). The silicon nitride film 18 is for protecting the energy generating element 2 and a drive circuit (not shown). Further, the tantalum film 19 is formed in a portion corresponding to the energy generating element 2 in the surface of the silicon nitride film 18 and prevents the silicon nitride film 18 from being deteriorated by a cavitation phenomenon generated in the ink. belongs to. The silicon nitride film 18 has a function as an insulating film for insulating the energy generating element 2 and the tantalum film 19 in addition to the function as a protective layer.

  One filter unit 20 is provided on each side of a sacrificial layer 15 (see FIG. 3) described later, and one filter unit 20 is provided with a plurality of through holes 17 in the silicon oxide film 16 and the silicon nitride film 18. Is made up of. In terms of the ink flow direction, the filter unit 20 is disposed at an intermediate position between the ink supply port 8 and the ink flow path 6.

  In addition, the performance as a filter of the filter part 20 is determined by the hole diameter and arrangement pitch of the through-hole 17, for example, the performance as a filter improves, so that a hole diameter is small. However, if the hole diameter is too small, ink pressure loss may occur in the filter unit 20 and the ink flow may deteriorate. Therefore, it is preferable to determine the hole diameter according to the size of dust or foreign matter scheduled to be captured, the characteristics of the ink used, and the like. For example, the opening area of one through-hole 17 may be about ½ of the opening area of the discharge port 7, so that dust and foreign matters larger than about ½ of the opening area of the discharge port 7 can be obtained. Captured by the filter unit 20.

  According to the recording head 50 configured as described above, since the filter unit 20 is provided, it is possible to prevent dust and foreign matter in the ink from entering the ink flow path 6 and the ejection port 7. Accordingly, it is difficult to cause a discharge failure due to clogging of dust and foreign matter in the discharge port 7 and the reliability of the recording head 50 is improved. Further, since the filter unit 20 is provided in the silicon oxide film 16 and the silicon nitride film 18, the mechanical strength is improved as compared with the filter disclosed in Patent Document 5. In addition, since the filter unit 20 is provided inside the recording head substrate 30 as compared with the filter disclosed in Patent Document 5, it is difficult to apply an impact force from the outside. Therefore, damage to the filter unit 20 in the manufacturing process is reduced. Furthermore, the silicon oxide film 16 and the silicon nitride film 18 are members generally provided in this type of recording head as a heat storage layer and a protective layer, respectively. That is, the recording head 50 has an advantage in that the filter unit 20 can be formed without using a special member.

  In the present embodiment, in addition to the silicon nitride film 18, a film made of oxidized silicon may be further formed as the protective layer.

(Second Embodiment)
Next, as a second embodiment of the present invention, an example of a recording head manufacturing method according to the present invention will be described below with reference to FIGS. The recording head manufacturing method described below is for manufacturing the recording head 50 shown in FIG.

  First, as shown in FIG. 3A, a field oxide film 13 is formed on the silicon substrate 1. Here, a silicon nitride film (not shown) is formed in advance in a region where the ink supply port 8 is opened, whereby a thin oxide film 13 a is formed in this region instead of the field oxide film 13. The silicon substrate 1 may have a crystal orientation of <100> plane or <110> plane.

  Next, as shown in FIG. 3B, after forming the BPSG film 14 so as to cover the entire field oxide film 13, a part of the BPSG film 14 is thin to match the region where the ink supply port 8 is opened. A part of the oxide film 13a is simultaneously removed to expose the silicon substrate 1.

  Next, as shown in FIG. 3C, a sacrificial layer 15 made of aluminum is selectively formed on the exposed position of the silicon substrate 1. The sacrificial layer 15 is removed at the same time as anisotropic etching for forming the ink supply port 8, which will be described later. It is not a thing.

  Next, as shown in FIG. 3D, the silicon oxide film 16 is formed as a heat storage layer so as to cover the BPSG film 14 and the sacrificial layer 15, and a plurality of through-holes 17 to be the filter unit 20 are formed. The formation of the through-hole 17 can be performed, for example, by a process common to the patterning of the silicon oxide film 16, thereby simplifying the process. Thereafter, the energy generating element 2, electrode wiring (not shown), drive circuit (not shown) and the like are further formed on the silicon oxide film 16.

  Next, as shown in FIG. 3E, a silicon nitride film 18 is formed as a protective layer so as to cover the entire silicon oxide film 16. At this time, the silicon nitride film 18 is also formed in the through hole 17. Thereafter, a tantalum film 19 is formed on a portion of the surface of the silicon nitride film 18 corresponding to the energy generating element 2.

  Next, as shown in FIG. 3F, a thermal oxide film 3 is formed on the entire back surface side of the silicon substrate 1, and a part thereof is removed to function as an etching mask for forming the ink supply port 8. To do.

  Next, as shown in FIG. 3G, a flow path resin layer 6a made of a meltable resin material is formed on the surface side of the silicon substrate 1 as a mold material for forming the ink flow path 6 (see FIG. 2). It is applied and patterned into a predetermined shape according to the shape of the ink flow path 6.

  Next, as shown in FIG. 3 (h), the covering resin layer 5 is formed so as to cover the flow path resin layer 6 a, and the discharge port 7 is formed at a position facing the energy generating element 2. Although not shown, a water repellent layer made of, for example, a dry film laminate is formed on the surface of the coating resin layer 5.

  Next, as shown in FIG. 3I, a protective material 9 made of an etching resistant material is attached in advance so as to cover the entire surface except for the back side of the silicon substrate 1, and then a strong alkali is used with the thermal oxide film 3 as a mask. An ink supply port 8 is formed by performing anisotropic etching using an aqueous solution. In addition, by this etching, the sacrificial layer 15 is simultaneously isotropically etched and removed. After this etching process is completed, the protective material 9 is removed.

  Etching in this step can be performed by a known general method. For example, the substrate 1 in the state shown in FIG. 3I is immersed in an 80 ° C. TMAH aqueous solution having a concentration of 22%. May be implemented. Here, in the configuration disclosed in Patent Document 5, since the filter is provided on the thermal oxide film on the back surface of the substrate, a strong alkaline aqueous solution or the like is formed on the filter during the anisotropic etching for forming the ink supply port. In some embodiments, the thermal oxide film 3 can be completely opened with an opening serving as a mask. Therefore, the above-described problem does not occur. In the recording head manufacturing method of the present invention, when the ink supply port is formed, the protective layer and the heat storage layer prevent communication between the ink flow path and the ink supply port. Therefore, even when the flow path is formed by a resin mold, the resin forming the mold does not come into contact with the etching solution for anisotropic etching.

  Next, as shown in FIG. 3J, the silicon nitride film 18 formed in the through hole 17 is removed by dry etching from the back side of the substrate 1 using the silicon oxide film 16 as a mask. The through hole 17 is penetrated. Then, the soluble flow path resin layer 6 a is eluted from the discharge port 7 and from the ink supply port 8 through the through hole 17, thereby forming the ink flow path 6.

  The recording head substrate 30 on which the nozzle portion is formed by the above steps is separated and cut into chips by a dicing saw or the like, and electric wiring (not shown) for driving the energy generating element 2 is joined to each chip. Thereafter, when a chip tank member (not shown) for storing ink to be supplied to the ink supply port 8 is joined to the ink supply port 8 side of each chip, the ink jet recording head 50 is completed.

(Third embodiment)
The present invention is not limited to the above-described embodiment, and the recording head may be, for example, as shown in FIG.

  The recording head 51 shown in FIG. 4 has an adhesive layer 22 in addition to the configuration of the recording head 50 of FIG. The adhesive layer 22 functions as a protective layer and serves to adhere the coating resin layer 5 and the recording head substrate 31. For example, the adhesive layer 22 is made of a thermoplastic resin (trade name: Hymal, manufactured by Hitachi Chemical Co., Ltd.). The silicon nitride film 18 and the tantalum film 19 are formed so as to cover. Furthermore, it is formed also on the member between the through-holes 17 of a filter part. The adhesive layer 22 can be formed, for example, by patterning with a positive resist.

  According to the recording head 51 configured as described above, the adhesive strength between the coating resin layer 5 and the recording head substrate 31 is improved, and the coating dendritic layer 5 is hardly peeled off. Further, since the adhesive layer 22 is also formed in the vicinity of the through hole 17 of the filter portion, the filter portion has a three-layer structure of the silicon oxide film 16, the silicon nitride film 18, and the adhesive layer 22, and the mechanical strength thereof is further increased. improves.

(A) is a schematic diagram showing an ink jet recording head according to an embodiment of the present invention, and (b) is a perspective view showing an example of an ink jet cartridge to which the present invention can be applied. 1 is a cross-sectional view illustrating an ink jet recording head according to a first embodiment of the present invention. (A)-(j) is typical sectional drawing which shows the manufacturing process of the inkjet recording head based on the Example of this invention in time series. It is sectional drawing which shows the inkjet recording head which concerns on the 2nd Example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 3 Thermal oxide film 5 Cover resin layer 6a Flow path resin layer 8 Ink supply port 13 Field oxide film 14 BPSG film 16 Silicon oxide film 17 Through-hole 18 Silicon nitride film 20 Filter part 30, 31 Recording head substrate 50, 51 Recording head

Claims (7)

Inkjet head comprising: a plurality of ejection ports for ejecting ink; a plurality of ink flow paths communicating with the plurality of ejection openings; and an ink supply port for supplying a liquid to the plurality of ink flow paths A manufacturing method of
Preparing a silicon substrate;
Forming a heat storage layer on the first surface of the silicon substrate;
Forming a plurality of through holes in the heat storage layer for communicating with the ink supply port;
Forming a heating element for discharging ink on the heat storage layer;
Forming a protective layer on the silicon substrate provided with a heat storage layer having a plurality of through-holes forming the heating element;
Forming a flow path constituting member constituting the plurality of ejection openings and the plurality of ink flow paths on the protective layer;
Forming the ink supply port on the silicon substrate by anisotropic etching from a second surface side facing the first surface of the substrate;
A step of removing a part of the protective film by using the heat storage layer in which the through holes are formed as a mask, and forming a filter by the plurality of through holes.   The method for manufacturing an ink jet recording head according to claim 1, wherein the protective layer includes silicon oxide or silicon nitride.   The method of manufacturing an ink jet recording head according to claim 1, further comprising a step of laminating a tantalum film on a portion of the protective layer corresponding to the heating element after the formation of the protective layer.   The method according to claim 1, further comprising a step of forming an adhesion improvement layer made of a thermoplastic resin for improving adhesion between the flow path component member and the protection layer on the protection layer after the formation of the protection layer. 3. A method for producing an ink jet recording head according to 2. An ink jet recording head that performs recording by discharging ink by heat generated by a heating element,
A silicon substrate comprising: a plurality of heating elements for discharging ink; and an ink supply port for supplying ink to the heating elements;
A plurality of ejection ports for ejecting ink and a plurality of ink flow paths communicating with each of the plurality of ink ejection ports and the ink supply port are formed corresponding to each of the plurality of heating elements. A flow path component for
An ink jet recording head in which a filter comprising a heat storage layer and a protective layer provided on the silicon substrate is formed at the ink supply port. A recording head substrate used in an inkjet recording head,
A silicon substrate formed with an ink supply port for supplying ink penetrating from one surface to the other surface;
A heat storage layer formed on the silicon substrate;
A heating element formed on the heat storage layer;
A protective layer laminated on the heat storage layer so as to cover the heating element,
A recording head substrate, wherein the heat storage layer and the protective layer are provided with a plurality of through holes that penetrate the heat storage layer and the protective layer and communicate with the ink supply port.   An ink jet cartridge comprising the ink jet recording head according to claim 5, further comprising an ink containing portion for containing ink to be supplied to the ink jet recording head.

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