Method for manufacturing a liquid dispensing head, liquid dispensing head

Abstract

We provide highly reliable liquid dispensing heads. [Solution] A method for manufacturing a liquid discharge head composed of a first channel substrate 107 and a second channel substrate 113, comprising: (a) a first substrate preparation step of providing an energy generating element 102 on the first surface 103a to form a first channel 116; (b) a second substrate preparation step of forming a second channel 115; (c) a first film formation step of forming a first protective film 108; (d) a first ashing step of ashing the second surface 107b; (e) a second film formation step of forming a second protective film 109 covering the second surface 107b; (f) a bonding step of joining the first channel substrate 107 and the second channel substrate 113; (g) a second ashing step of ashing the first surface 107a; and (h) a hydrofluoric acid treatment step of treating the first surface 107a with hydrofluoric acid, wherein the second film formation step, bonding step, second ashing step, and hydrofluoric acid treatment step are carried out in this order.

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a substrate for a liquid ejection head and a liquid ejection head.

Background Art

[0002] As a liquid ejection head for ejecting a liquid such as ink, a configuration including a nozzle and a substrate for a liquid ejection head in which a flow path communicating with the nozzle is formed is known. In a substrate for a liquid ejection head having such a configuration, a protective film for protecting the surface of the substrate and the flow path may be provided.

[0003] Patent Document 1 discloses a configuration in which a liquid-resistant protective film is provided so as to cover a predetermined portion of a substrate as a protective film for protecting the surface of the substrate and the flow path. In particular, when the substrate is a silicon substrate, it is important to provide such a protective film because the inner wall surface of the flow path is easily eroded by ink.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] When a substrate for a liquid ejection head is configured by joining a plurality of substrates, for the purpose of improving the adhesion of the substrates, another protective film may be provided on the protective film. However, in the film formation process of these protective films, there is a risk that the protective film is formed in an unintended portion, or unintended components remain on the surface of the substrate when the protective film is removed, thereby reducing the reliability of the substrate for the liquid ejection head.

[0006] The present invention has been made in view of the above problems, and an object thereof is to provide a highly reliable liquid ejection head. [Means for solving the problem]

[0007] To achieve the above objective, the method for manufacturing a liquid discharge head of the present invention is as follows: A method for manufacturing a liquid discharge head composed of a first channel substrate and a second channel substrate, (a) A first substrate preparation step in which an energy generating element for generating energy to discharge liquid is provided on the first surface of the first channel substrate, and a first channel is formed in the first channel substrate that penetrates from the first surface to the second surface opposite to the first surface, (b) A second substrate preparation step of forming a second channel in the second channel substrate that penetrates from the third surface to the fourth surface opposite to the third surface, (c) A first film formation step of forming a first protective film that covers at least a part of the first surface of the first channel substrate and the wall surface of the first channel, (d) A first ashing step of ashing the second surface of the first channel substrate, (e) A second film formation step of forming a second protective film that covers the second surface of the first channel substrate, (f) A bonding step of joining the second surface of the first channel substrate and the third surface of the second channel substrate via an adhesive so that the first channel and the second channel are in communication with each other, (g) A second ashing step of ashing the first surface of the first channel substrate, (h) A hydrofluoric acid treatment step of treating the first surface of the first channel substrate with hydrofluoric acid, Includes, The second film formation step, the bonding step, the second ashing step, and the hydrofluoric acid treatment step are The procedure is characterized by being carried out in the following order. Furthermore, in order to achieve the above-mentioned objectives, the method for manufacturing a liquid discharge head of the present invention is as follows: A method for manufacturing a liquid discharge head composed of a first channel substrate and a second channel substrate, (a) A first substrate preparation step of providing the energy generating element that generates energy for discharging liquid on the first surface of the first flow channel substrate, (b) A first film formation step of forming a first protective film that covers at least a part of the first surface of the first channel substrate and the wall surface of the first channel, (c) A second film formation step of forming a second protective film that covers the second surface of the first channel substrate, (d) A bonding step of joining the second surface of the first channel substrate opposite to the first surface and the third surface of the second channel substrate via an adhesive, (e) A first film removal step of removing at least a portion of the first protective film provided on the first surface of the first channel substrate, Includes, The second film formation step and the first film removal step are performed in this order. [Effects of the Invention]

[0008] According to the present invention, a highly reliable liquid dispensing head can be provided. [Brief explanation of the drawing]

[0009] [Figure 1] This is a schematic exploded perspective view of the liquid dispensing head. [Figure 2] This is a schematic cross-sectional view of a substrate for a liquid discharge head according to the first embodiment. [Figure 3A] This is a schematic cross-sectional view of the first channel substrate after the deposition of the first protective film. [Figure 3B] This is a schematic cross-sectional view of the first channel substrate with a portion of the first protective film removed. [Figure 3C] This is a schematic cross-sectional view of the ashing first channel substrate. [Figure 3D] This is a schematic cross-sectional view of the first channel substrate after the deposition of the second protective film. [Figure 3E] This is a schematic cross-sectional view of the substrate after the bonding process. [Figure 3F] This is a schematic cross-sectional view of an ashing substrate. [Figure 3G] This is a schematic cross-sectional view of the substrate after the second protective film has been removed. [Figure 4A] This is a schematic cross-sectional view of the first channel substrate after the deposition of the first protective film. [Figure 4B] It is a schematic cross-sectional view of the first flow path substrate after forming the second protective film. [Figure 4C] It is a schematic cross-sectional view of the substrate after the bonding process.

Mode for Carrying Out the Invention

[0010] Hereinafter, the mode for carrying out this invention will be illustratively and specifically described based on examples with reference to the drawings. Note that the dimensions, materials, shapes, relative arrangements, etc. of the components described in this embodiment should be appropriately changed according to the configuration of the apparatus to which the invention is applied and various conditions. That is, it is not intended to limit the scope of this invention to the following embodiments.

[0011] <First Embodiment> The liquid ejection head 10 according to the first embodiment of the present invention and a recording apparatus including the liquid ejection head 10 will be described. The recording apparatus includes a conveyance unit that conveys a recording medium and a liquid ejection head 10 that ejects liquid toward the recording medium conveyed by the conveyance unit. The liquid ejection head 10 is an inkjet recording head that ejects ink as a liquid to record an image on the recording medium.

[0012] [Configuration of Liquid Ejection Head] Referring to FIG. 1, the configuration of the liquid ejection head 10 according to the first embodiment will be described. FIG. 1 is a schematic exploded perspective view of the liquid ejection head 10. The liquid ejection head 10 includes a sub-tank unit 11, an electric circuit board 12, a base member 13, a flow path unit 14, a recording element substrate 15, an electric wiring member 16, a cover 17, and an electric connection member 18.

[0013] The recording element substrate 15 is formed by connecting a substrate 100 for the liquid ejection head and a pitch conversion member, and a flow path for the liquid supplied from the sub-tank unit 11 to flow is formed. The recording element substrate 15 is provided with a row of ejection ports configured by arranging a plurality of ejection ports. The flow path unit 14 includes a storage chamber for storing liquid and the like, and supplies the liquid supplied from the sub-tank unit 11 to the recording element substrate 15.

[0014] The sub-tank unit 11 stores the liquid supplied from outside the liquid discharge head 10 and used for image recording. The sub-tank unit 11 is equipped with a pressure adjustment mechanism and also has the function of controlling the pressure in the flow path of the liquid discharge head 10. The sub-tank unit 11 may also have a circulation unit for circulating the liquid between the sub-tank unit 11 and the recording element substrate 15. The sub-tank unit 11 is fitted with a cover 17, and the sub-tank unit 11 is covered and protected by the cover 17.

[0015] The electrical circuit board 12 receives signals from a signal transmitting unit provided in the main body of the recording device to drive the recording element board 15. The electrical circuit board 12 is connected to the signal transmitting unit of the recording device via an electrical connection member 18 and receives signals from the recording device to drive, for example, an energy generating element provided on the recording element board 15. The electrical connection member 18 is a member that electrically connects the main body of the recording device and the liquid discharge head 10, and is, for example, a flexible cable.

[0016] The electrical wiring member 16 electrically connects the electrical circuit board 12 and the recording element board 15. Signals received by the electrical circuit board 12 are transmitted to the recording element board 15 via the electrical wiring member 16.

[0017] The base member 13 is a support member that supports the flow channel unit 14. The flow channel unit 14 is fixed to the base member 13, for example, by adhesive. The base member 13 also has a cover (not shown) for protecting the flow channel unit 14 and the recording element substrate 15 connected to the flow channel unit 14 from the outside.

[0018] Figure 1 shows a liquid discharge head 10 in which four flow path units 14 and a recording element substrate 15 are arranged side by side. However, in applying the present invention, the liquid discharge head 10 may be configured with fewer than four or more flow path units 14 and recording element substrates 15 arranged side by side.

[0019] [Configuration of the circuit board for the liquid dispensing head] Referring to Figure 2, the configuration of the liquid discharge head substrate 100 according to the first embodiment will be described. Figure 2 is a schematic cross-sectional view of the liquid discharge head substrate 100 according to the first embodiment. The liquid discharge head substrate 100 has a plurality of nozzles 101a formed thereon as discharge ports for discharging liquid. Figure 2 shows a partial cross-section of the liquid discharge head substrate 100, showing one of the nozzles 101a of the liquid discharge head substrate 100 and a flow path communicating with the nozzle 101a.

[0020] The substrate 100 for the liquid discharge head is composed of a first channel substrate 107 and a second channel substrate 113.

[0021] The first channel substrate 107 has a first surface 107a and a second surface 107b opposite to the first surface 107a. A wiring layer 106 and a protective layer 105 for protecting the wiring layer 106 are laminated on the first surface 107a in that order. The first channel substrate 107 is also provided with a nozzle forming member 101 (discharge port forming member) on which a nozzle 101a is formed, an energy generating element 102 for generating energy for discharging liquid, and an electrical connection part 104. 01, the energy generating element 102, and the electrical connection part 104 are all provided on the first surface 107a side, i.e., on the protective layer 105. The energy generating element 102 and the electrical connection part 104 are electrically connected via the wiring layer 106. In this specification, when a component or film is provided on the surface of a substrate, it includes not only cases where the component or film is in direct contact with the surface of the substrate, but also cases where it is provided on the surface of the substrate via another film or layer.

[0022] The nozzle forming member 101 has a nozzle 101a and a nozzle channel 101b communicating with the nozzle 101a. The nozzle channel 101b is a pressure chamber in which an energy generating element 102 is provided. When viewed in a direction perpendicular to the first surface 107a, the nozzle 101a and the energy generating element 102 are positioned to overlap each other, and liquid is discharged from the nozzle 101a along a direction perpendicular to the first surface 107a. As the energy generating element 102, for example, an element that heats or boils liquid, such as a heater element, or an element that applies pressure to liquid by utilizing volume change, such as a piezoelectric element, can be used.

[0023] A first channel 116 is formed inside the first channel substrate 107, penetrating from the first surface 107a to the second surface 107b. The first channel 116 includes individual channels 116a that open to the first surface 107a and communicate with the nozzle channel 101b, and a common liquid chamber 116b (common channel) that opens to the second surface 107b and communicates with the channel of the second channel substrate 113 and the individual channels 116a. The first channel substrate 107 is provided with a plurality of individual channels 116a and a plurality of common liquid chambers 116b. A plurality of individual channels 116a may communicate with one common liquid chamber 116b, or one individual channel 116a may communicate with one common liquid chamber 116b.

[0024] A first protective film 108 and a second protective film 109 are formed on the first channel substrate 107. The first protective film 108 and the second protective film 109 are deposited (formed) on the first channel substrate 107 in this order.

[0025] The first protective film 108 is a protective film provided primarily for the purpose of protecting the first channel substrate 107 from liquid such as ink. The first protective film 108 is provided so as to cover at least the second surface 107b and the first channel 116 of the first channel substrate 107. On the other hand, the first protective film 108 is not provided in the area of ​​the first surface 107a (protective layer 105) where the nozzle forming member 101, energy generating element 102, and electrical connection part 104 are provided. Furthermore, the first protective film 108 does not cover the nozzle forming member 101, energy generating element 102, or electrical connection part 104 themselves.

[0026] The second protective film 109 is a protective film (adhesion film) provided primarily for the purpose of protecting the first channel substrate 107 and improving the adhesion between the first channel substrate 107 and the second channel substrate 113. The second protective film 109 is provided so as to cover at least the second surface 107b of the first channel substrate 107.

[0027] The second channel substrate 113 has a third surface 113a that is joined to the second surface 107b of the first channel substrate 107, and a fourth surface 113b that is the opposite surface of the third surface 113a. The second surface 107b of the first channel substrate 107 and the third surface 113a of the second channel substrate 113 are joined by an adhesive 110. The fourth surface 113b is a joining surface that is joined to the pitch conversion member.

[0028] A second channel 115 is formed inside the second channel substrate 113, penetrating from the third surface 113a to the fourth surface 113b. The second channel 115 communicates with the common liquid chamber 116b of the first channel 116. Multiple second channels 115 are formed in the second channel substrate 113.

[0029] The second channel substrate 113 has a first protective film 111 and a second protective film 112 formed on it. The first protective film 111 and the second protective film 112 are formed (deposited) on the second channel substrate 113 in this order. The first protective film 111 is the same as the first protective film 108 provided on the first channel substrate 107. It has the following functions. The first protective film 111 is provided so as to cover the third surface 113a, the fourth surface 113b, and the second channel 115. The second protective film 112 has the same function as the second protective film 109 provided on the first channel substrate 107. The second protective film 112 is provided so as to cover the third surface 113a and the fourth surface 113b.

[0030] With this configuration, a flow path is formed inside the liquid discharge head substrate 100 for the liquid supplied from the sub-tank unit 11 to flow through. In the first embodiment, the flow path of the liquid discharge head substrate 100 is configured to include a nozzle flow path 101b, a first flow path 116, and a second flow path 115. The liquid passes through the second flow path 115, the first flow path 116, and the nozzle flow path 101b in that order and is discharged from the nozzle 101a. In the case of a configuration in which the liquid is circulated, the liquid that is not discharged from the nozzle 101a is recovered into the sub-tank unit 11 by passing through another first flow path 116 and second flow path 115.

[0031] As described above, a first protective film 108 and a second protective film 109 are deposited on the first channel substrate 107 that constitutes the liquid discharge head substrate 100. At this time, the first protective film 108 is patterned (removed) so as not to cover the portion of the first surface 107a of the first channel substrate 107 where the nozzle forming member 101 is provided or the energy generating element 102. The deposition of the second protective film 109 can be performed either before or after the patterning of the first protective film 108.

[0032] Let's consider the case where a first protective film 108 is formed, and a second protective film 109 is formed before patterning of the first protective film 108. In this case, organic components such as resist and stripping solution applied when patterning the first protective film 108 may remain on the second protective film 109, potentially contaminating it. This would reduce the adhesion of the second protective film 109. On the other hand, if, for example, oxygen plasma treatment is performed to remove the organic components, the second protective film 109 may deteriorate, potentially reducing its adhesion.

[0033] Let's consider the case where a first protective film 108 is deposited, and then a second protective film 109 is deposited after patterning of the first protective film 108. In this case, the second protective film 109 is also deposited on the first surface 107a through the first channel 116. The first surface 107a is a device formation surface on which devices such as the energy generating element 102 and the electrical connection part 104 are formed. Therefore, the deposition of the second protective film 109 on the first surface 107a may prevent the device characteristics and electrical characteristics from exhibiting the desired performance.

[0034] The following describes a method for manufacturing the liquid discharge head substrate 100 according to the first embodiment, which is reliable and can suppress deterioration in adhesion and performance.

[0035] [Manufacturing method for substrates for liquid dispensing heads] Referring to Figures 3A to 3G, a method for manufacturing the liquid discharge head substrate 100 according to the first embodiment will be described illustratively. Figures 3A to 3G are explanatory diagrams of the method for manufacturing the liquid discharge head substrate 100, and are schematic cross-sectional views in the same cross-section as in Figure 2.

[0036] First, a wiring layer 106 and a protective layer 105 are sequentially laminated on the first surface 107a of the first channel substrate 107. Then, an energy generating element 102 and an electrical connection part 104 are provided on the first surface 107a, and a first channel 116 is formed inside the first channel substrate 107. These steps together constitute the first substrate preparation step. In this first embodiment, the first channel substrate 107 is a silicon substrate and is formed using a silicon wafer.

[0037] The formation of the first channel 116 (individual channel 116a and common liquid chamber 116b) is due to reactive ions. This is done using the Bosch process, a type of etching. The Bosch process is a method of forming etching grooves perpendicular to the substrate by alternating between coating and etching. Alternatively, a method can be used in which unpenetrated holes are formed and then the substrate is thinned by backgrinding or CMP to create through-holes.

[0038] Next, a first film deposition step is performed in which a first protective film 108 is deposited on the first channel substrate 107 prepared in the first substrate preparation step. Figure 3A shows the first channel substrate 107 after the deposition of the first protective film 108. Preferably, the first protective film 108 is deposited so as to cover the entire silicon surface (the surface without any laminates) of the first channel substrate 107, including at least the wall surface of the first channel 116. In the first film deposition step, the first protective film 108 is deposited so as to cover the energy generating element 102 and electrical connection part 104 on the first surface 107a, as well as the wall surface of the first channel 116 and the entire surface of the first channel substrate 107.

[0039] The first protective film 108 is formed by comprising an oxide of at least one metal selected from the group consisting of, for example, Ti, Zr, Hf, V, Nb, and Ta, and is more preferably formed by TiO (titanium oxide).

[0040] For forming the first protective film, various deposition methods such as chemical vapor deposition (CVD), sputtering, and atomic layer deposition (ALD) can be employed. Among these, atomic layer deposition is preferred due to its good penetration characteristics. These deposition methods should be selected according to the structure of the exposed channel surface.

[0041] Next, a first film removal step is performed to partially remove the first protective film 108 on the first surface 107a. Specifically, the first protective film 108 is removed in the region of the first surface 107a where the energy generating element 102 and electrical connection part 104 are formed, and in the region where the nozzle forming member 101 will be provided later. Figure 3B shows the first channel substrate 107 with the first protective film 108 partially removed. In the first embodiment, when viewed in a direction perpendicular to the first surface 107a, the first protective film 108 is removed in at least the region overlapping with the energy generating element 102 and electrical connection part 104, and in the region where the nozzle forming member 101 is provided (contacts).

[0042] The first protective film 108 can be removed by wet etching or dry etching after a photolithography process, which includes forming a resist on the first surface 107a, exposing the removal area, and then removing the film. The unwanted resist is then removed with an organic stripping solution. The partial removal process of the first protective film 108 (first film removal process) may be considered as part of the first film formation process. After the first film formation process, organic contaminants 130 may remain on the first protective film 108 on the second surface 107b, which is opposite to the first surface 107a.

[0043] Next, a first ashing process is performed on the first channel substrate 107. The first ashing process is performed to remove organic contaminants 130 on the second surface 107b. Figure 3C shows the ashing first channel substrate 107. Ashing is a method of removing organic matter by generating an oxygen plasma, reacting oxygen radicals with organic matter, and decomposing the organic matter into CO2 and H2O, which are then vaporized.

[0044] When TiO is deposited as the first protective film 108 using the ALD method with TiCl4, chlorine components contained in the precursor may be present in the deposited TiO. When chlorine reacts with the ink components, it reduces the adhesion reliability at the bonding interface. Therefore, by ashing the second surface 107b, the chlorine composition ratio in the TiO can be reduced, thereby improving adhesion reliability. A chlorine composition ratio of 1% or less in the TiO is preferable.

[0045] Next, a second film deposition step is performed in which a second protective film 109 is deposited on the first channel substrate 107. Figure 3D shows the first channel substrate 107 after the deposition of the second protective film 109. The second protective film 109 is deposited on the second surface 107b of the first channel substrate 107, on top of the first protective film 108.

[0046] The second protective film 109 is selected from the group consisting of, for example, a SiC film, a SiCN film, an OSiOC film, and an OSiOCN film, and is more preferably a SiC film. In other words, the second protective film 109 is formed by including at least one of SiC, SiCN, OSiOC, and OSiOCN.

[0047] A method for depositing the second protective film 109 is the same as the method for depositing the first protective film 108. To selectively deposit the film on the second surface 107b, chemical vapor deposition (CVD) and sputtering are particularly preferred, and chemical vapor deposition (CVD) is more preferred.

[0048] During the deposition of the second protective film 109, the first channel 116 penetrates the first channel substrate 107 from the first surface 107a to the second surface 107b. Therefore, in the second deposition process, gas flows through the first channel 116, which is a through-hole, to the first surface 107a side, and a small amount of the second protective film is deposited on the first surface 107a of the first channel substrate 107. The second protective film that is unintentionally deposited on the first surface 107a in this way is distinguished from the second protective film 109 on the second surface 107b and designated as the second protective film 120. Since the energy generating element 102 and the electrical connection part 104 are formed on the first surface 107a, if the second protective film 120 is deposited on these, for example, it may affect the device characteristics and electrical characteristics.

[0049] In parallel with the first substrate preparation step, first film deposition step, first ashing step, and second film deposition step for forming the first channel substrate 107, the second substrate preparation step, first film deposition step, and second film deposition step for forming the second channel substrate 113 are carried out. However, the formation of the first channel substrate 107 and the formation of the second channel substrate 113 may be carried out in order, and the order is not important. In the first embodiment, the second channel substrate 113 is a silicon substrate, similar to the first channel substrate 107, and is formed using a silicon wafer.

[0050] The second substrate preparation step is the step of forming a second channel 115 on the second channel substrate 113. The formation of the second channel 115 can be carried out in the same manner as the formation of the first channel 116. The first film deposition step is the step of depositing a first protective film 111 on the second channel substrate 113. The deposition of the first protective film 111 can be carried out in the same manner as the deposition of the first protective film 108. The second film deposition step is the step of depositing a second protective film 112 on the second channel substrate 113. The deposition of the second protective film 112 can be carried out in the same manner as the deposition of the second protective film 109. In addition, after the first film deposition step, the first ashing step may be carried out in the same manner as with the first channel substrate 107. However, the types of films, deposition methods, and channel formation methods do not necessarily have to be the same as with the first channel substrate 107, and may differ between the first channel substrate 107 and the second channel substrate 113 in order to obtain the desired performance.

[0051] Next, a bonding process is performed to join the first channel substrate 107 and the second channel substrate 113. The substrate formed by joining the second surface 107b of the first channel substrate 107 and the third surface 113a of the second channel substrate 113 is referred to as substrate 119 for convenience. Figure 3E shows the substrate 119 after the bonding process.

[0052] The first channel substrate 107 and the second channel substrate 113 are joined by an adhesive 110. The adhesive 110 is formed (applied) on the second protective film 109 on the second surface 107b of the first channel substrate 107, or on the second protective film 109 on the third surface 113a of the second channel substrate 113. Figure 3E shows an example in which the adhesive 110 is formed on the first channel substrate 107. Then, the first channel The second surface 107b and the third surface 113a are joined via adhesive 110 so that 116 and the second flow path 115 are in communication.

[0053] The adhesive 110 is preferably made of a material that has low coating properties and minimal inclusion of air bubbles, and is also preferably made of a low-viscosity material that makes it easy to reduce the thickness of the adhesive 110. The adhesive 110 preferably contains a resin selected from the group consisting of epoxy resin, acrylic resin, silicone resin, benzocyclobutene resin, polyamide resin, polyimide resin, and urethane resin. As for the curing method of the adhesive 110, for example, a thermosetting method and an ultraviolet delayed curing method can be used. If any of the substrates is ultraviolet transparent, the ultraviolet curing method can also be used.

[0054] As a method for applying the adhesive 110, for example, an adhesive transfer method using a transfer substrate can be used. Specifically, a transfer substrate is prepared, and the adhesive 110 is thinly and uniformly applied to the transfer substrate by a spin coating method or a slit coating method. Then, by bringing the adhesive surface (second surface 107b) of the first channel substrate 107 into contact with the applied adhesive 110, the adhesive 110 can be transferred only to the adhesive surface of the first channel substrate 107. The size of the transfer substrate is preferably the same as or larger than the first channel substrate 107. Suitable transfer substrates include films such as silicon, glass, PET, PEN, and PI. In addition, screen printing and dispensing can be used as methods for directly forming the adhesive 110 on the first channel substrate 107. In the first embodiment, the adhesive 110 was applied to the first channel substrate 107 as an example, but the adhesive 110 may also be applied to the second channel substrate 113.

[0055] Next, a second ashing step is performed on the surface of the substrate 119 on which the energy generating element 102 is formed, i.e., the first surface 107a of the first channel substrate 107. Figure 3F shows the ashing substrate 119. The second ashing step can be performed using the same method as the first ashing step. The second ashing step causes the second protective film 120 formed on the first surface 107a to become SiO2. The SiO2-converted second protective film 120 is referred to as the second protective film 121.

[0056] Next, a second film removal step is performed to remove the SiO-converted second protective film 121 on the first surface 107a. Figure 3G shows the substrate 119 from which the SiO-converted second protective film 121 has been removed.

[0057] Methods for removing the SiO-converted second protective film 121 include wet treatment using hydrofluoric acid and dry etching using F-based gas. Since dry etching can sometimes make it difficult to achieve a suitable selectivity ratio with respect to the energy generating element 102 and the protective layer 105, wet treatment using hydrofluoric acid is more preferable. Therefore, in this example, a hydrofluoric acid treatment step, which involves wet treatment using hydrofluoric acid, is performed as the second film removal step.

[0058] Next, a nozzle formation process is performed in which a nozzle forming member 101 is formed on the substrate 119. Through the nozzle formation process, the nozzle 101a communicates with the first channel 116 via the nozzle channel 101b. Subsequently, the wafer is separated into individual pieces, completing the substrate 100 for the liquid discharge head as shown in Figure 2.

[0059] Furthermore, in the assembly process, a pitch conversion member with a pitch conversion channel formed therein is connected to the liquid discharge head substrate 100 to obtain a recording element substrate 15, and an electrical wiring member 16 is electrically connected to the recording element substrate 15. Then, the recording element substrate 15, channel unit 14, base member 13, electrical circuit board 12, sub-tank unit 11, and cover 17 are assembled to complete the liquid discharge head 10.

[0060] Thus, in the first embodiment, the first substrate preparation step, the first film deposition step, and the first ashing step are performed. The second film formation process, bonding process, second ashing process, and hydrofluoric acid treatment process are carried out in this order. Furthermore, for the second channel substrate 113, processes such as the second substrate preparation process are carried out before the bonding process. By carrying out the second film formation process, bonding process, second ashing process, and hydrofluoric acid treatment process in this order, contamination of the surface of the second protective film, which is in close contact with another substrate via the adhesive, can be suppressed. Ultimately, this enables the manufacture of a highly reliable liquid dispensing head.

[0061] The above manufacturing method is merely an example, and additional steps may be added as appropriate. However, needless to say, no steps that would cause organic contamination of the bonding surface should be added between the first ashing step for the first channel substrate 107 shown in Figure 3D and the bonding step for joining the first channel substrate 107 and the second channel substrate 113 shown in Figure 3E.

[0062] <Second Embodiment> Next, a second embodiment of the present invention will be described. The second embodiment differs from the first embodiment in the method of manufacturing the substrate for the liquid discharge head. Hereinafter, only the differences between the configuration of the second embodiment and the configuration of the first embodiment will be described. Components in the configuration of the second embodiment that are the same as those in the configuration of the first embodiment are denoted by the same reference numerals and their description is omitted.

[0063] [Manufacturing method for substrates for liquid dispensing heads] Referring to Figures 4A to 4C, a method for manufacturing the liquid discharge head substrate 100 according to the second embodiment will be described illustratively. Figures 4A to 4C are explanatory diagrams of the method for manufacturing the liquid discharge head substrate 100, and are schematic cross-sectional views in the same cross-section as in Figure 2.

[0064] First, similar to the first embodiment, a first substrate preparation step is performed, and a first channel substrate 107 is prepared in which a wiring layer 106 and a protective layer 105 are laminated, an energy generating element 102 and an electrical connection part 104 are provided, and a first channel 116 is formed. Then, similar to the first embodiment, a first film deposition step is performed to deposit a first protective film 108 on the first channel substrate 107. The type of film and film deposition method of the first protective film 108 are the same as in the first embodiment. Figure 4A shows the first channel substrate 107 after the deposition of the first protective film 108 according to the second embodiment.

[0065] In this example, the first channel 116 is formed before the bonding process (bonding the first channel substrate 107 and the second channel substrate 113), which will be described later. However, the first channel substrate 107 may be processed after the bonding process to form the first channel 116. In other words, the first substrate preparation process may not include the process of forming the channel, and the first channel formation process for forming the first channel 116 may be separated from the first substrate preparation process.

[0066] Next, as a second film deposition step, a second protective film 109 is deposited on the first channel substrate 107. Figure 4B shows the first channel substrate 107 after the deposition of the second protective film 109 according to the second embodiment. The second protective film 109 is deposited on the second surface 107b of the first channel substrate 107, on top of the first protective film 108. The type of film and deposition method of the second protective film 109 are the same as in the first embodiment. If the first channel 116 is already formed on the first channel substrate 107, in the second film deposition step, a small amount of the second protective film 120 is also deposited on the first protective film 108 on the first surface 107a through the first channel 116.

[0067] In the second embodiment, as in the first embodiment, the process of forming the second channel substrate 113 is carried out in parallel with the various processes of forming the first channel substrate 107. In this example, similar to the first channel substrate 107, a second channel formation process may be carried out after the bonding process to form the second channel 115 in the second channel substrate 113. In other words, the second channel formation process may be carried out separately from the second substrate preparation process.

[0068] Next, a bonding process is performed to join the first channel substrate 107 and the second channel substrate 113. The bonding process is carried out in the same manner as in the first embodiment, and a substrate 119 is obtained by joining the second surface 107b of the first channel substrate 107 and the third surface 113a of the second channel substrate 113. Figure 4C shows the substrate 119 after the bonding process according to the second embodiment.

[0069] Next, a first film removal step is performed to remove a portion of the first protective film 108. In the first film removal step, at least the portion of the first protective film 108 formed on the first surface 107a of the first channel substrate 107 that contains the energy generating element 102 and the electrical connection portion 104, and the portion of the area where the nozzle forming member 101 will be provided later, is removed. The first film removal step can be performed in the same manner as the first film removal step of the first embodiment.

[0070] In the second embodiment, the first film removal step removes both the first protective film 108 on the first surface 107a and the second protective film 120 on the first protective film 108 together. In other words, in the second embodiment, the first film removal step can remove (lift off) the second protective film 120 that adhered to the first surface 107a in the second film formation step together with the first protective film 108. The substrate 119 after the first film removal step is the same as the substrate 119 of the first embodiment shown in Figure 3G.

[0071] After the first film removal process, a nozzle formation process and assembly process similar to those in the first embodiment are performed to complete the liquid discharge head substrate 100 and the liquid discharge head 10.

[0072] Thus, in the second embodiment, the first substrate preparation step, the first film deposition step, the second film deposition step, the bonding step, and the first film removal step are performed in this order. Furthermore, for the second channel substrate 113, steps such as the second substrate preparation step are performed before the bonding step. By performing the second film deposition step and the first film removal step in this order, contamination of the surface of the second protective film, which is in close contact with another substrate via the adhesive, can be suppressed. Consequently, a highly reliable liquid dispensing head can be manufactured.

[0073] The above manufacturing method is merely an example, and additional steps may be added as appropriate, and the order of the steps may be changed. For example, when forming a channel after substrate bonding, a second protective film 109 or the like to improve adhesion may be formed before substrate bonding, and a first protective film 108 or the like to protect the channel may be formed after the channel is formed after substrate bonding. Then, by performing a first film removal step to remove the first protective film 108 on the first surface 107a, the second protective film 109 formed on the first surface 107a together with the first protective film 108 can be removed. Also, for example, the nozzle formation step to form the nozzle forming member 101 may be performed before the first film formation step, rather than after the bonding step.

[0074] <First Example> Next, we will describe examples of actual manufacturing using the manufacturing methods for the liquid discharge head substrate 100 according to each of the embodiments described above. First, we will describe a first embodiment in which a liquid discharge head 10 was manufactured using the manufacturing method according to the first embodiment.

[0075] First, as a first substrate preparation step, a protective layer 105 made of SiCN and a wiring layer 106 were laminated onto the first channel substrate 107, and an energy generating element 102 made of TaSiN and an electrical connection part 104 made of Au were formed. Then, the first channel 116 was formed inside the first channel substrate 107 by reactive ion etching using the Bosch process.

[0076] Next, as the first film deposition step, a first protective film 108 was deposited on the first channel substrate 107. In this example, TiO was deposited as the first protective film 108 by ALD using TiCl4. In this example, the thickness of the first protective film 108 was set to 30 nm. The first channel substrate after the first film deposition step The structure of plate 107 is the same as that shown in Figure 3A.

[0077] Next, as a first film removal step, a dry film resist, spin-coated on a film, was transferred to the first surface 107a of the first channel substrate 107. Then, exposure and development were performed so that the energy generating element 102, the electrical connection part 104, and the contact area of ​​the nozzle forming member 101 formed on the first surface 107a were exposed. After that, the first protective film 108 (TiO) on the first surface 107a of the first channel substrate 107 was etched with buffered hydrofluoric acid, and the unwanted resist was removed with a stripping solution. In this first film removal step, the first protective film 108 on the first surface 107a was selectively removed, while organic contaminants 130 remained on the first protective film 108 on the second surface 107b. The structure of the first channel substrate 107 after the first film removal step is the same as that shown in Figure 3B.

[0078] Next, as the first ashing step, oxygen ashing was performed on the second surface 107b of the first channel substrate 107. The ashing conditions were a processing temperature of 225°C, an RF bias of 0W, and a processing time of 135s. The ashing process successfully removed all of the organic contaminants 130 remaining on the second surface 107b. Furthermore, the ashing process reduced the chlorine composition ratio in the first protective film 108(TiO) on the second surface 107b from 1.5% to 0.8%, improving resistance to ink. The structure of the first channel substrate 107 after the first ashing step is the same as that shown in Figure 3C.

[0079] Next, as a second film deposition step, a second protective film 109 was deposited on the second surface 107b of the first channel substrate 107. In this example, SiC was deposited as the second protective film 109 by plasma CVD. Through the second film deposition step, the second protective film 120 was also deposited in the areas in contact with the energy generating element 102, the electrical connection part 104, and the nozzle forming member 101 on the first surface 107a, through the first channel 116. The structure of the first channel substrate 107 after the second film deposition step is the same as that shown in Figure 3D.

[0080] In addition, a second channel substrate 113 was formed in parallel with the first channel substrate 107. The second channel substrate 113 was formed by performing a second substrate preparation step, a first film deposition step, and a second film deposition step.

[0081] Next, as a bonding step, a film-like spin-coated adhesive 110 was brought into contact with the second surface 107b of the first channel substrate 107 while heating, thereby forming the adhesive 110 only on the second surface 107b. Benzocyclobutene was used as the adhesive 110. Then, the first channel substrate 107 and the second channel substrate 113 were bonded together and heat-cured to produce the substrate 119. The structure of the substrate 119 after the bonding step is the same as that shown in Figure 3E.

[0082] Next, as a second ashing step, oxygen ashing was performed on the first surface 107a of the substrate 119. The ashing conditions were a processing temperature of 225°C, an RF bias of 0W, and a processing time of 68s. By performing the ashing treatment, the SiC second protective film 120 deposited on the first surface 107a was converted to SiO. The structure of the substrate 119 after the second ashing step is the same as that shown in Figure 3F.

[0083] Next, as a second film removal step (hydrofluoric acid treatment step), the SiO-based second protective film 121 on the first surface 107a was removed using buffered hydrofluoric acid. The hydrofluoric acid treatment time was 60 s. The structure of the substrate 119 after the second film removal step is the same as that shown in Figure 3G.

[0084] Next, in the nozzle formation process, a nozzle forming member 101 was formed on the first surface 107a of the substrate 119. Then, after the substrate 119 was separated into individual chips, a pitch conversion member was connected to the liquid discharge head substrate 100 to obtain the recording element substrate 15. Then, in the assembly process, the recording element The circuit board 15, flow path unit 14, base member 13, electrical circuit board 12, sub-tank unit 11, and cover 17 were assembled, and the electrical wiring member 16 and electrical connection member 18 were connected to complete the liquid discharge head 10.

[0085] <Second Example> Next, a second embodiment will be described in which the liquid discharge head 10 is manufactured using the manufacturing method according to the second embodiment.

[0086] First, as a first substrate preparation step, a protective layer 105 made of SiCN and a wiring layer 106 were laminated onto the first channel substrate 107, and an energy generating element 102 made of TaSiN and an electrical connection part 104 made of Au were formed. Then, the first channel 116 was formed inside the first channel substrate 107 by reactive ion etching using the Bosch process.

[0087] Next, as the first film deposition step, a first protective film 108 was deposited on the first channel substrate 107. In this example, TiO was deposited as the first protective film 108 by ALD using TiCl4. In this example, the thickness of the first protective film 108 was set to 30 nm. The structure of the first channel substrate 107 after the first film deposition step is the same as that shown in Figure 4A.

[0088] Next, as a second film deposition step, a second protective film 109 was deposited on the second surface 107b of the first channel substrate 107. In this example, SiC was deposited as the second protective film 109 by plasma CVD. Through the second film deposition step, the second protective film 120 was also deposited on the first protective film 108 on the first surface 107a via the first channel 116. The structure of the first channel substrate 107 after the second film deposition step is the same as that shown in Figure 4B.

[0089] In addition, a second channel substrate 113 was formed in parallel with the first channel substrate 107. The second channel substrate 113 was formed by performing a second substrate preparation step, a first film deposition step, and a second film deposition step.

[0090] Next, as a bonding step, a film-like spin-coated adhesive 110 was brought into contact with the second surface 107b of the first channel substrate 107 while heating, thereby forming the adhesive 110 only on the second surface 107b. Benzocyclobutene was used as the adhesive 110. Then, the first channel substrate 107 and the second channel substrate 113 were bonded together and heat-cured to fabricate the substrate 119. The structure of the substrate 119 after the bonding step is the same as that shown in Figure 4C.

[0091] Next, as the first film removal step, a dry film resist, which had been spin-coated on a film, was transferred to the first surface 107a of the first channel substrate 107. Then, exposure and development were performed so that the energy generating element 102, the electrical connection part 104, and the contact area of ​​the nozzle forming member 101 formed on the first surface 107a were exposed. After that, the first protective film 108 (TiO) on the first surface 107a of the first channel substrate 107 was etched with buffered hydrofluoric acid, and the unwanted resist was removed with a stripping solution. At this time, the etching of the first protective film 108 (TiO) lifted off and removed the second protective film 120 (SiO) on the first protective film 108. The structure of the substrate 119 after the first film removal step is the same as that shown in Figure 3G.

[0092] Next, in the nozzle formation process, a nozzle forming member 101 was formed on the first surface 107a of the substrate 119. Then, after the substrate 119 was separated into individual chips, a pitch conversion member was connected to the liquid discharge head substrate 100 to obtain the recording element substrate 15. Then, in the assembly process, the recording element substrate 15, flow path unit 14, base member 13, electrical circuit board 12, sub-tank unit 11, and cover 17 were assembled, and the electrical wiring member 16 and electrical connection member 18 were connected to complete the liquid discharge head 10.

[0093] This embodiment includes the following methods. (Method 1) A method for manufacturing a liquid discharge head composed of a first channel substrate and a second channel substrate, (a) A first substrate preparation step in which an energy generating element that generates energy for discharging liquid is provided on the first surface of the first channel substrate, and a first channel is formed in the first channel substrate that penetrates from the first surface to the second surface opposite to the first surface, (b) A second substrate preparation step of forming a second channel in the second channel substrate that penetrates from the third surface to the fourth surface opposite to the third surface, (c) A first film formation step of forming a first protective film that covers at least a part of the first surface of the first channel substrate and the wall surface of the first channel, (d) A first ashing step of ashing the second surface of the first channel substrate, (e) A second film formation step of forming a second protective film that covers the second surface of the first channel substrate, (f) A bonding step of joining the second surface of the first channel substrate and the third surface of the second channel substrate via an adhesive so that the first channel and the second channel are in communication with each other, (g) A second ashing step of ashing the first surface of the first channel substrate, (h) A hydrofluoric acid treatment step of treating the first surface of the first channel substrate with hydrofluoric acid, Includes, A method for manufacturing a liquid dispensing head, characterized in that the second film formation step, the bonding step, the second ashing step, and the hydrofluoric acid treatment step are carried out in this order. (Method 2) The method for manufacturing a liquid discharge head according to Method 1, characterized in that the first substrate preparation step, the first film formation step, the first ashing step, and the second film formation step are carried out in this order. (Method 3) A method for manufacturing a liquid discharge head composed of a first channel substrate and a second channel substrate, (a) A first substrate preparation step of providing the energy generating element that generates energy for discharging liquid on the first surface of the first flow channel substrate, (b) A first film formation step of forming a first protective film that covers at least a part of the first surface of the first channel substrate and the wall surface of the first channel, (c) A second film formation step of forming a second protective film that covers the second surface of the first channel substrate, (d) A bonding step of joining the second surface of the first channel substrate opposite to the first surface and the third surface of the second channel substrate via an adhesive, (e) A first film removal step of removing at least a portion of the first protective film provided on the first surface of the first channel substrate, Includes, A method for manufacturing a liquid dispensing head, characterized in that the second film formation step and the first film removal step are carried out in this order. (Method 4) The method for manufacturing a liquid dispensing head according to Method 3, characterized in that the first substrate preparation step, the first film formation step, the second film formation step, the bonding step, and the first film removal step are carried out in this order. (Method 5) (f) A first channel formation step of forming a first channel in the first channel substrate, (g) A second channel formation step in which a second channel is formed on a second channel substrate, Includes, A method for manufacturing a liquid discharge head according to method 3 or 4, characterized in that the first channel formation step and the second channel formation step are performed before the joining step. (Method 6) A method for manufacturing a substrate for a liquid discharge head according to any one of methods 1 to 5, characterized in that the first protective film is formed of TiO. (Method 7) The method for manufacturing a liquid discharge head according to any one of methods 1 to 6, characterized in that the second protective film is formed comprising at least one of SiC, SiCN, SiOC, and SiOCN. (Method 8) A method for manufacturing a liquid discharge head according to any one of methods 1 to 7, characterized in that the first film formation step is a step of forming the first protective film by atomic layer deposition. (Method 9) A method for manufacturing a liquid discharge head according to any one of methods 1 to 8, characterized in that the second film formation step is a step of forming the second protective film by plasma CVD. (Method 10) The first protective film is formed of TiO, The method for manufacturing a liquid discharge head according to Method 1, characterized in that the first ashing step is a step of removing organic matter by oxygen ashing. (Composition 1) A liquid dispensing head manufactured by the manufacturing method described in Method 10, A liquid dispensing head characterized in that the chlorine composition ratio of the first protective film is 1% or less. [Explanation of symbols]

[0094] 10...Liquid discharge head, 102...Energy generating element, 107...First channel substrate, 107a...First surface, 107b...Second surface, 108...First protective film, 109...Second protective film, 110...Adhesive, 113...Second channel substrate, 113a...Third surface, 113b...Fourth surface, 115...Second channel, 116...First channel

Claims

1. A method for manufacturing a liquid discharge head composed of a first channel substrate and a second channel substrate, (a) A first substrate preparation step in which an energy generating element for generating energy to discharge liquid is provided on the first surface of the first flow channel substrate, and a first flow channel is formed in the first flow channel substrate that penetrates from the first surface to the second surface opposite to the first surface, (b) A second substrate preparation step of forming a second channel in the second channel substrate that penetrates from the third surface to the fourth surface opposite to the third surface, (c) A first film formation step of forming a first protective film that covers at least a part of the first surface of the first channel substrate and the wall surface of the first channel, (d) A first ashing step of ashing the second surface of the first channel substrate, (e) A second film formation step of forming a second protective film that covers the second surface of the first flow channel substrate, (f) A bonding step of joining the second surface of the first channel substrate and the third surface of the second channel substrate via an adhesive so that the first channel and the second channel are in communication with each other, (g) A second ashing step of ashing the first surface of the first channel substrate, (h) A hydrofluoric acid treatment step of treating the first surface of the first channel substrate with hydrofluoric acid, Includes, A method for manufacturing a liquid dispensing head, characterized in that the second film formation step, the bonding step, the second ashing step, and the hydrofluoric acid treatment step are carried out in this order.

2. The method for manufacturing a liquid discharge head according to claim 1, characterized in that the first substrate preparation step, the first film formation step, the first ashing step, and the second film formation step are carried out in this order.

3. A method for manufacturing a liquid discharge head composed of a first channel substrate and a second channel substrate, (a) A first substrate preparation step of providing an energy generating element that generates energy for discharging liquid on the first surface of the first flow channel substrate, (b) A first film formation step of forming a first protective film that covers at least a portion of the first surface of the first channel substrate, (c) A second film formation step of forming a second protective film that covers the second surface of the first channel substrate opposite to the first surface, (d) A bonding step of joining the second surface of the first channel substrate and the third surface of the second channel substrate via an adhesive, (e) A first film removal step of removing at least a portion of the first protective film provided on the first surface of the first flow channel substrate, Includes, A method for manufacturing a liquid dispensing head, characterized in that the second film formation step and the first film removal step are carried out in this order.

4. The method for manufacturing a liquid dispensing head according to claim 3, characterized in that the first substrate preparation step, the first film formation step, the second film formation step, the bonding step, and the first film removal step are performed in this order.

5. (f) A first channel formation step of forming a first channel in the first channel substrate, (g) A second channel formation step of forming a second channel in the second channel substrate, Includes, The method for manufacturing a liquid discharge head according to claim 3 or 4, characterized in that the first channel formation step and the second channel formation step are performed before the joining step.

6. The first protective film is characterized by being formed of TiO, as described in claim 1 or 3. A method for manufacturing a liquid dispensing head.

7. The method for manufacturing a liquid dispensing head according to claim 1 or 3, characterized in that the second protective film is formed comprising at least one of SiC, SiCN, SiOC, and SiOCN.

8. The method for manufacturing a liquid dispensing head according to claim 1 or 3, characterized in that the first film formation step is a step of forming the first protective film by atomic layer deposition.

9. The method for manufacturing a liquid discharge head according to claim 1 or 3, characterized in that the second film formation step is a step of forming the second protective film by a plasma CVD method.

10. The first protective film is formed of TiO, The method for manufacturing a liquid discharge head according to claim 1, characterized in that the first ashing step is a step of removing organic matter by oxygen ashing.

11. A liquid dispensing head manufactured by the manufacturing method described in claim 10, A liquid dispensing head characterized in that the chlorine composition ratio of the first protective film is 1% or less.

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