Method for manufacturing liquid ejection head and recording element substrate

Abstract

To efficiently supply thermal energy required for joining a lead wiring part to a terminal.SOLUTION: A manufacturing method of a liquid discharge head, which comprises a recording element substrate 101 and an electric wiring substrate 102 comprising a lead wiring part 122 on one surface thereof, where the recording element substrate 101 has a discharge port forming member 111, a support substrate 110 provided with a support surface 110a for supporting the discharge port forming member 111 and a terminal 113 electrically connected to the lead wiring part 122 on the support surface 110a, includes a step of pressurizing a contact portion between the lead wiring part 122 and the terminal 113, from the electric wiring substrate 102 side, while heating a predetermined site of the support substrate 110, with lead wiring part 122 contacted with the terminal 113. A distance (d) between the predetermined site and the terminal 113 is shorted than a distance (D) between the predetermined site and the discharge port forming member 111.SELECTED DRAWING: Figure 1

Description

[Technical field]

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

[0002] The liquid ejection head has a recording element substrate that ejects liquid, an electric wiring substrate that is electrically connected to the recording element substrate, and a support member that supports the recording element substrate and the electric wiring substrate. The recording element substrate has an ejection port forming member in which a plurality of ejection ports are formed, and a support substrate having a support surface that supports the ejection port forming member. A lead wiring portion is formed on one surface of the electric wiring substrate. Terminals that are electrically connected to the lead wiring portion are formed on the support surface of the support substrate. In the above-mentioned method for manufacturing a liquid ejection head, the electric wiring board and the recording element board are arranged so that the lead wiring parts are in contact with the terminals. The lead wiring parts and the terminals are joined by applying heat and pressure from the electric wiring board side. Patent Document 1 describes a method for joining the lead wiring parts and the terminals by using ultrasonic waves in addition to heating and pressure. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2005-219238 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the above-mentioned bonding method, since the electric wiring board, which has a lower thermal conductivity than the recording element board, is heated, it is necessary to heat the lead wiring part and the terminal at a very high temperature for a long time to provide sufficient thermal energy to bond them together, which may increase the time required for bonding and reduce the manufacturing efficiency. In addition, since the ejection port forming member is not designed to withstand high temperatures, if the recording element substrate is directly heated, the ejection port may be damaged by the heat and the shape of the ejection port may change.

[0005] An object of the present invention is to solve the above problems and efficiently supply the thermal energy required to join the lead wiring portion and the terminal. [Means for solving the problem]

[0006] In order to achieve the above object, the present invention provides a method for manufacturing a liquid ejection head having a recording element substrate for ejecting liquid, and an electric wiring substrate having a lead wiring portion on one surface, the recording element substrate having an ejection port forming member having a plurality of ejection ports, a support substrate having a support surface for supporting the ejection port forming member, and a terminal formed on the support surface and electrically connected to the lead wiring portion, the method including applying pressure to the contact portion between the lead wiring portion and the terminal from the electric wiring substrate side while heating a predetermined portion of the support substrate with the lead wiring portion in a state in which the lead wiring portion is in contact with the terminal, the distance between the predetermined portion and the terminal being shorter than the distance between the predetermined portion and the ejection port forming member. Effect of the Invention

[0007] According to the present invention, it is possible to efficiently supply the thermal energy required to join the lead wiring portion of the electric wiring board and the terminal of the recording element board. [Brief description of the drawings]

[0008] [Figure 1] 5A to 5C are diagrams illustrating a manufacturing method of the liquid ejection head according to the first embodiment of the present invention. [Diagram 2] FIG. 2 is a schematic diagram illustrating a configuration of a liquid ejection head. [Diagram 3] FIG. 2 is a schematic diagram illustrating a configuration of a recording element substrate. [Figure 4] FIG. 2 is a diagram showing a configuration of an electric wiring board. [Diagram 5]FIG. 2 is a schematic diagram showing the arrangement of an electric wiring board and a recording element board. [Figure 6] FIG. 11 is a process diagram for explaining a sealing procedure. [Figure 7] 5A to 5C are diagrams for explaining a joining structure between the holding member, the electric wiring board, and the recording element board. [Figure 8] FIG. 13 is a schematic diagram showing the configuration of another recording element substrate. [Figure 9] 6A to 6C are diagrams illustrating a manufacturing method of a liquid ejection head according to a second embodiment of the present invention. [Figure 10] 10A to 10C are diagrams illustrating a manufacturing method of a liquid ejection head according to a third embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. However, the components described in the embodiment are merely examples and are not intended to limit the scope of the present invention.

[0010] (First embodiment) First, the configuration of a liquid ejection head to which the manufacturing method of the present invention is applied will be described. Fig. 2(a) is a perspective view showing a schematic configuration of a liquid ejection head. Fig. 2(b) is an exploded perspective view showing a part of the liquid ejection head shown in Fig. 2(a) disassembled. Referring to Figs. 2(a) and 2(b), the liquid ejection head 100 has a recording element substrate 101 that ejects liquid such as ink, an electric wiring substrate 102 having a lead wiring portion on one surface, and a support member 103 that supports the recording element substrate 101 and the electric wiring substrate 102. Here, the surface of the electric wiring substrate 102 supported by the support member 103 is an example of the "one surface" on which the lead wiring portion is formed.

[0011] The support member 103 has a support section 104 that supports the recording element substrate 101, a support section 105 that supports the electric wiring substrate 102, and a flow path 105 for supplying liquid to the recording element substrate 101. The support section 104 is large enough to support the entire recording element substrate 101. The support section 105 is provided around the support section 104 so as to be one step higher. The material of the support member 103 may be, for example, a resin material or a ceramic material such as Al2O3. In this embodiment, modified PPE (Polyphenyleneether) is used as the material of the support member 103. The support member 103 is formed by molding.

[0012] Fig. 3 is a diagram for explaining the configuration of the recording element substrate 101. Fig. 3(a) is a perspective view of the recording element substrate 101. Fig. 3(b) is an enlarged view showing a part of the recording element substrate 101 when viewed from the side joined to the electric wiring substrate 102. Fig. 3(c) is an enlarged view showing a part of the recording element substrate 101 when viewed from the side joined to the support member 103. 3(a) and 3(b), the recording element substrate 101 has a support substrate 110 mainly made of Si, and an ejection port forming member 111. The ejection port forming member 111 has a plurality of ejection ports 115 that eject liquid. These ejection ports 115 are arranged in a plurality of rows.

[0013] The support substrate 110 has a support surface 110a that supports the ejection port forming member 11, and a plurality of terminals 113 that are electrically connected to the lead wiring portions of the electric wiring board 102 are formed on this support surface 110a. The plurality of terminals 113 are arranged along both ends in the row direction of the ejection ports 115. The row direction of the ejection ports 115 coincides with the longitudinal direction of the support substrate 110. The thickness of the support substrate 110 is, for example, 0.6 mm to 0.8 mm.

[0014] The support substrate 110 is provided with pressure generating elements 112 for discharging liquid for each discharge port 115, and further provided with electrical wiring (not shown) made of Al or the like for sending electrical signals to the pressure generating elements 112. This electrical wiring is electrically connected to terminals 113. The terminals 113 supply the driving signal (driving power) supplied via the electrical wiring substrate 102 to the pressure generating elements 112 via the electrical wiring. Upon receiving the driving signal, the pressure generating elements 112 generate heat and heat the liquid. By heating the liquid, air bubbles are generated. Droplets are discharged from the discharge ports 115 by utilizing the pressure generated when the air bubbles are generated.

[0015] The support substrate 110 is also provided with a liquid supply port 114 for supplying liquid to the vicinity of the pressure generating element 112. The liquid supply port 114 is a through-hole penetrating the support substrate 110. The liquid supply port 114 can be formed by anisotropic etching using the crystal orientation of Si. As an etching solution, for example, a strong alkaline solution such as TMAH (tetramethylammonium hydroxide) or KOH (potassium hydroxide) can be used. An Au layer is formed on the surface of the terminal 113. For example, plating is used to form this Au layer.

[0016] The ejection port forming member 111 is joined to the support substrate 110 so that its end portion is adjacent to the terminal 113. The ejection port forming member 111 is produced by the following procedure. First, a soluble resin is applied onto the support substrate 110 to form a mold material that will become a liquid flow path. For example, a positive photoresist (ODUR, manufactured by Tokyo Ohka Kogyo Co., Ltd.) is applied by spin coating, and then exposed and developed to form a flow path pattern. Next, a material that will become the discharge port forming member 111 is applied by spin coating. The material of the discharge port forming member 111 is required to have high mechanical strength, adhesion to the base, resistance to liquid, and the like, as well as resolution for forming a fine pattern of the discharge ports 115. Examples of materials that satisfy these characteristics include cationic polymerization type epoxy resin compositions. Examples of epoxy resins include reaction products of bisphenol A and epichlorohydrin, and reaction products of bromobisphenol A and epichlorohydrin. Examples of reaction products include reaction products of phenol novolac or o-cresol novolac and epichlorohydrin. The epoxy resin preferably has an epoxy equivalent of 2000 or less, and more preferably has an epoxy equivalent of 1000 or less. The photo-cationic polymerization initiator for curing the epoxy resin may be a compound that generates an acid upon irradiation with light. For example, an aromatic sulfonium salt or an aromatic iodonium salt may be used. If necessary, a wavelength sensitizer may be added. For example, the wavelength sensitizer may be SP-100, which is commercially available from ADEKA Corporation.

[0017] Next, the portion coated with the material of the discharge port forming member 111 is exposed to light through a photomask, and then the unexposed area is removed with a developer to form a pattern of the discharge ports 115, etc. Finally, the mold material is dissolved from the liquid supply port 114 and the discharge ports 115 to form the discharge port forming member 111. As shown in Figures 3(a) and 3(c), step portions 116 are provided at both ends in the longitudinal direction of the support substrate 110. The step portions 116 are formed parallel to the row direction of the terminals 113. The step portions 116 are an example of a predetermined portion that is heated when joining the terminals 113 and the lead wiring portions of the electric wiring board 102. As with the formation of the liquid supply port 114, the step portions 116 can be formed by using anisotropic etching. The step portion 116 is provided on the surface opposite to the support surface 110a. The step portion 116 is closer to the terminal 113 than the discharge port forming member 111. The thickness of the step portion 116 of the support substrate 110 is thinner than the thickness of the portion of the support substrate 110 where the terminal 113 is formed.

[0018] Fig. 4 is a diagram for explaining the configuration of the electric wiring board 102. Fig. 4(a) is a partially enlarged view of the electric wiring board 102, and Fig. 4(b) is a cross-sectional view taken along the line AA of Fig. 4(a). 4(a) and 4(b), the electric wiring board 102 has a base film 120 and a lead wiring section 122 supported and fixed to the base film 120. The base film 120 is made of a foldable insulating organic resin such as a polyimide film (PI film). The base film 120 is provided with device holes 121 for exposing the row of ejection ports 115 of the recording element substrate 101. One surface of the base film 120 is configured to cover the entire lead wiring portion 122. A plurality of connection pads 123 are formed on the other surface of the base film 120. Electrical signals are supplied to these connection pads 123 from the recording device body on which the liquid ejection head is mounted. The one surface of the base film 120 is an example of "one surface" of the electric wiring board 102 on which the lead wiring portion 122 is formed.

[0019] The lead wiring portion 122 extends from an edge of the device hole 121 to one end of the base film 120. The entire lead wiring portion 122 is supported and fixed to the base film 120. The end of the lead wiring portion 122 does not protrude into the device hole 121. The end of the lead wiring portion 122 on the device hole 121 side serves as a connection portion that is electrically connected to the terminal 113 of the recording element substrate 102. The method of joining the lead wiring portion 122 fixed to the base film 120 to the terminal 113 is called a chip-on-film method (COF method).

[0020] The other end of the lead wiring portion 122 is electrically connected to a connection pad 123. The lead wiring portion 122 is provided for each connection pad 123. A driving signal (driving power) can be supplied from the recording device main body to the recording element substrate 101 via the connection pad 123 and the lead wiring portion 122. The lead wiring portion 122 may be made of a metal wiring (conductive member) such as Al. In this embodiment, the main component of the lead wiring portion 122 is Cu. The connection portion of the lead wiring portion 122 with the terminal 113 is plated with Ni, and an Au plating layer is formed thereon. The lead wiring portion 122 is fixed to the base film 120 using an adhesive containing epoxy, which has a glass solidification temperature of about 60°C to 70°C, as its main component.

[0021] Next, a method for manufacturing the liquid ejection head according to the first embodiment of the present invention will be described. The method for manufacturing the liquid ejection head of this embodiment includes a bonding step for bonding the lead wiring portion 122 of the electric wiring board 102 and the terminal 113 of the recording element board 101 to each other. In carrying out the bonding step, the electric wiring board 102 and the recording element board 101 are arranged so that the lead wiring portion 122 abuts against the terminal 113. FIG. 5 shows a schematic arrangement of the electric wiring board 102 and the recording element board 101. The recording element board 101 is provided with an alignment mark 131, and the electric wiring board 102 is provided with an alignment mark 132. The electric wiring board 102 and the recording element board 101 are arranged so that these marks 131 and 132 have a predetermined positional relationship. The electric wiring board 102 and the recording element board 101 can be moved to any desired position by using a fixing table having a function of adsorbing by suction.

[0022] The procedure of the joining step will be described in detail below. 1A to 1E are process diagrams illustrating a bonding procedure in a manufacturing method for a liquid ejection head according to the present embodiment, each of which is a process diagram showing a bonding procedure based on the structure of the AA cross section in FIG. 1(a), the recording element substrate 101 and the electric wiring substrate 102 are placed at predetermined positions so that the lead wiring portion 122 and the terminal 113 face each other. At this time, positioning is performed based on the marks 131 and 132 so that the ejection port forming member 111 is exposed from the device hole 121. Next, as shown in FIG. 1(b), the lead wiring portion 122 is brought into contact with the terminal 113.

[0023] Next, as shown in FIG. 1(c), the heating tool 200 is brought into contact with the step portion 116 of the recording element substrate 101 to heat it. The heating tool 200 has a surface with an oxidation-resistant coating mainly made of Cu, and a heater is provided inside. The distance d between the step portion 116 and the terminal 113 is smaller than the distance D between the step portion 116 and the discharge port forming member 111. In this embodiment, the distance from the heated surface (heating portion) of the step portion 116 to the terminal 113 in the vertical direction (thickness direction of the support substrate 110) is defined as d. Also, the distance from the heating portion of the step portion 116 to the discharge port forming member 111 in the horizontal direction (longitudinal direction of the support substrate 110) is defined as D. Note that the distances d and D may be defined in any way as long as they can indicate the transfer distance of thermal energy. For example, d may be defined as the linear distance between the heating portion of the step portion 116 and the terminal 113, and D may be defined as the linear distance between the heating portion of the step portion 116 and the discharge port forming member 111. The temperature of the heating tool 200 is, for example, 400° C. to 500° C. The distance d is, for example, 0.2 mm, and the distance D is, for example, 0.4 mm. Furthermore, in the support substrate 110, the thermal energy supplied from the heating tool 200 is supplied to the terminal 113 side via the thin step portion 116. By making the portion to be heated thin, the area in which heat is diffused can be limited. Therefore, the contact portion between the terminal 113 and the lead wiring portion 122 can be heated efficiently. In contrast, in the case of a support substrate of a constant thickness that does not have the thin step portion 116, the area in which heat is diffused is wide, so the efficiency of heating the contact portion between the terminal 113 and the lead wiring portion 122 decreases. The above distances d and D are preferably determined appropriately based on the thermal diffusivity of the support substrate 110 so that the discharge port 115 is not damaged by heat.

[0024] 1(d), a pressure tool 201 is used to apply pressure to the contact portions between the terminals 113 and the lead wiring portions 122 from the side of the electric wiring board 102. The pressure tool 201 is movable in a direction perpendicular to the surface of the base film 120, and can apply a constant load (pressure) to the contact portions between the terminals 113 and the lead wiring portions 122. The load (pressure) is, for example, 10N to 20N. By applying pressure to the contact portion between the heated terminal 113 and the lead wiring portion 122, the Au layers of the terminal 113 and the lead wiring portion 122 are crushed, resulting in an electrical connection between the terminal 113 and the lead wiring portion 122.

[0025] The width l of the pressure tool 201 is narrower than the width L of the input terminal 113. Here, the width l and the width L are widths in the longitudinal direction of the support substrate 110 (the row direction of the ejection ports 115). The width l is, for example, 0.1 mm, and the width L is, for example, 0.2 mm. By making the width l narrower than the width L in this way, it is possible to prevent pressure from being transmitted to the step portion 116, which is thinner than other portions. As a result, it is possible to prevent the recording element substrate 101 from cracking due to pressure. The state shown in FIG. 1(e) is the state in which the terminal 113 and the lead wiring portion 122 are electrically connected.

[0026] After the above-mentioned bonding step is performed, a sealing step is performed. 6A and 6B are process diagrams illustrating a sealing procedure in the method for manufacturing a liquid ejection head according to the present embodiment, showing the process based on the structure of the AA cross section in FIG. First, as shown in FIG. 6(a), the sealant 106 is supplied through the gap between the discharge port forming member 111 and the base film 120 to seal the joint between the terminal 113 and the lead broken line portion 122.

[0027] The sealing material 106 flows from the discharge port forming member 111 side to the end side of the support substrate 110 through a space (gap) formed by the plurality of lead wiring parts 122 and the support substrate 110. This flow of the sealing material 106 allows the entire exposed surface of the joint part between the terminal 113 and the lead broken line part 122 to be covered with the sealing material 106 as shown in FIG. 6(b). For the sealing material 106, it is preferable to use a thermosetting sealing material mainly composed of epoxy resin having high fluidity. The viscosity of the epoxy resin is, for example, 1 Pa·s to 5 Pa·s (25°C, 100 rotations). The thixotropic index is, for example, 0.5 to 1.5 (10 / 100 rotations), and the gelation time is, for example, 50 seconds to 200 seconds. Finally, the sealant 106 is cured to bond the recording element substrate 101 and the electric wiring substrate 102 more firmly.

[0028] After the above-mentioned sealing process is performed, the recording element substrate 101 and the electric wiring substrate 102 are bonded to the support member 103. Fig. 7 shows the state in which the recording element substrate 101 and the electric wiring substrate 102 are bonded to the support member 103. The structure shown in Fig. 7 corresponds to the structure of the AA cross section in Fig. 2(a). 7, the recording element substrate 101 is fixed to the support member 103 using an adhesive 107, and the electric wiring substrate 102 is fixed to the support member 103 using an adhesive 108. The adhesives 107 and 108 are preferably resistant to liquids. In this embodiment, the adhesives 107 and 108 are mainly made of epoxy resin.

[0029] An air dispenser is used to apply adhesive 107 to a predetermined location on support portion 104 of recording element substrate 101. Adhesive 108 is applied to the entire surface of support portion 105 of recording element substrate 101 by a transfer method. After application of adhesives 107 and 108, recording element substrate 101 and electric wiring board 102 are attached to predetermined locations on support member 103. Thereafter, adhesives 107 and 108 are cured at a temperature of 100° C. or higher. Note that curing of adhesives 107 and 108 and curing of sealant 106 may be performed in a single process. Through the above curing step, the liquid ejection head 100 shown in FIG. 2(a) is obtained.

[0030] According to the manufacturing method of the liquid ejection head of this embodiment described above, the thermal energy required to bond the lead wiring portion 122 of the electrical wiring board 102 and the terminal 113 of the recording element board 101 can be efficiently supplied in the bonding process. 1(a) to 1(e), for example, the step portion 116 of the recording element substrate 101 is directly heated. Therefore, compared to the case where the recording element substrate 101 is heated via the electric wiring substrate 102, the contact portion between the lead wiring portion 122 and the terminal 113 can be heated more efficiently.

[0031] Furthermore, since the distance d between the step portion 116 and the terminal 113 is smaller than the distance D between the step portion 116 and the discharge port forming member 111, the thermal energy supplied from the heating tool 200 is transmitted to the terminal 113 before being transmitted to the discharge port forming member 111. Therefore, the Au layer of the terminal 113 and the Au layer of the lead wiring portion 122 can be efficiently heated, and damage to the discharge port 115 due to heat can be suppressed. In particular, by arranging the step portion 116 at a position closer to the terminal 113 than the discharge port forming member 111, the contact portion between the lead wiring portion 122 and the terminal 113 can be heated more efficiently.

[0032] Moreover, the terminal 113 is located between the end of the support substrate 110 and the ejection port forming member 111. More specifically, the terminal 113 is located between the stepped portion 116, which is the heated portion (predetermined portion), and the ejection port forming member 111. With this arrangement, a sufficient distance can be secured between the stepped portion 116 and the ejection port forming member 111, further improving the effect of suppressing damage to the ejection port 115 due to heat. Furthermore, the step portion 116 is provided on the surface opposite to the support surface 110a. With this arrangement, the heating tool 200 and the pressure tool 201 can sandwich the vicinity of the contact portion between the lead wiring portion 122 and the terminal 113, so that deformation of the recording element substrate 101 caused by stress during pressure application can be suppressed.

[0033] The thickness of step portion 116 of support substrate 110 is thinner than the thickness of the portion of support substrate 110 where terminal 113 is formed. By using this thin step portion 116 as the heating portion, the area in which heat is diffused is limited. This makes it possible to heat the contact portion between lead wiring portion 122 and terminal 113 more efficiently. Since the step portion 116 can be formed by anisotropic etching, machining or the like is not required, and an increase in the number of manufacturing steps can be suppressed.

[0034] Furthermore, step portion 116 is located at the end of support substrate 110 in the longitudinal direction, and applies a constant load to the surface of electric wiring board 102 opposite to the surface on which lead wiring portion 122 is formed. The longitudinal width of the region where this load is applied (same as width l of pressure tool 201) is smaller than longitudinal width L of terminal. With this configuration, pressure is not transmitted to thin step portion 116, so that it is possible to prevent recording element substrate 101 from cracking when pressure is applied. The terminals 113 and the step portions 116 are formed at both ends of the support substrate 110. In the process shown in FIG. 1(a) to FIG. 1(e), the terminal 113 at one end is brought into contact with the lead wiring portion 122 of the electric wiring board 102, and the terminal 113 at the other end is brought into contact with the lead wiring portion 122 of another electric wiring board 102. The terminals 113 at both ends may be joined to the lead wiring portion 122 at the same time. In this case, a heating tool 200 and a pressure tool 201 are disposed at each end. Also, after the terminal 113 at one end is joined to the lead wiring portion 122, the terminal 113 at the other end may be joined to the lead wiring portion 122. In this case, only one heating tool 200 and one pressure tool 201 may be used.

[0035] Second embodiment Next, a method for manufacturing a liquid ejection head according to a second embodiment of the present invention will be described. The manufacturing method of the liquid ejection head of this embodiment includes a bonding process for bonding the lead wiring portion 122 of the electric wiring board 102 and the terminal 113 of the recording element board 101, but the portion to be heated (predetermined portion) is different from that of the first embodiment. In the following, in order to avoid duplication, a description of the same configuration as the first embodiment will be omitted.

[0036] 8 is a diagram for explaining the configuration of a recording element substrate 101 used in the manufacturing method of a liquid ejection head of this embodiment. The recording element substrate 101 has a support substrate 110, an ejection port forming member 111, and terminals 113. The ejection port forming member 111 and the terminals 113 are the same as those described in the first embodiment. The support substrate 110 differs from the first embodiment in that the thickness of at least the portion from the terminals 113 to the end is constant and the support substrate 110 does not have a step portion 116. The end faces 117 are an example of a predetermined portion to be heated when joining the terminals 113 and the lead wiring portions 112. The end faces 117 are located at both ends in the longitudinal direction of the support substrate 110. The end faces 117 are closer to the terminals 113 than the ejection port forming members 111. Such end faces 117 can be produced in the process of cutting out the recording element substrate 101.

[0037] 9A to 9E are process diagrams illustrating a bonding procedure in the manufacturing method of the recording head of this embodiment, showing the process steps based on the structure of the AA cross section in FIG. First, as shown in Fig. 9(a), the recording element substrate 101 and the electric wiring substrate 102 are arranged at predetermined positions so that the lead wiring portion 122 and the terminal 113 face each other. This process is basically the same as the process in Fig. 1(a). Next, as shown in Fig. 9(b), the lead wiring portion 122 is brought into contact with the terminal 113. This step is also basically the same as the step in Fig. 1(b).

[0038] Next, as shown in FIG. 9(c), the heating tool 200 is brought into contact with the end surface 117 of the recording element substrate 101 and heated. The distance d between the end surface 117 and the terminal 113 is smaller than the distance D between the end surface 117 and the discharge port forming member 111. In this embodiment, the distance from the heated surface (heating portion) of the end surface 117 to the terminal 113 in the horizontal direction (longitudinal direction of the support substrate 110) is defined as d. Also, the distance from the heating portion of the end surface 117 to the discharge port forming member 111 in the horizontal direction is defined as D. Note that the distances d and D may be defined in any way as long as they can indicate the transfer distance of thermal energy. For example, d may be defined as the linear distance between the heating portion of the end surface 117 and the terminal 113, and D may be defined as the linear distance between the heating portion of the end surface 117 and the discharge port forming member 111. The temperature of the heating tool 200 is, for example, 400°C to 500°C. The distance d is, for example, 0.1 mm, and the distance D is, for example, 0.4 mm.

[0039] 9(d), a pressure tool 201 is used to apply pressure to the contact portion between the terminal 113 and the lead wiring portion 122 from the side of the electric wiring board 102. The pressure tool 201 is the same as that described in the first embodiment. The width l of the pressure tool 201 is narrower than the width L of the input terminal 113. By applying pressure to the contact portion between the heated terminal 113 and the lead wiring portion 122, the Au layers of the terminal 113 and the lead wiring portion 122 are crushed, and as a result, the terminal 113 and the lead wiring portion 122 are electrically connected. The state shown in FIG. 9(e) is the state in which the terminal 113 and the lead wiring portion 122 are electrically connected. After the above bonding step is performed, a sealing step and a curing step are performed in the same manner as in the first embodiment, thereby obtaining the liquid ejection head 100 shown in FIG. 2(a).

[0040] In the manufacturing method of the liquid ejection head of this embodiment described above, as in the first embodiment, the thermal energy required to join the lead wiring portion 122 of the electrical wiring board 102 and the terminal 113 of the recording element board 101 can be efficiently supplied. 9(a) to 9(e), the end surface 117 of the recording element substrate 101 is directly heated. Therefore, compared to the case where the recording element substrate 101 is heated via the electric wiring substrate 102, the contact portion between the lead wiring portion 122 and the terminal 113 can be heated more efficiently.

[0041] Furthermore, since the distance d between the end face 117 and the terminal 113 is smaller than the distance D between the end face 117 and the discharge port forming member 111, the thermal energy supplied from the heating tool 200 is transmitted to the terminal 113 before being transmitted to the discharge port forming member 111. Therefore, the Au layer of the terminal 113 and the Au layer of the lead wiring portion 122 can be efficiently heated, and damage to the discharge port 115 due to heat can be suppressed. Moreover, the recording element substrate 101 has a certain degree of thickness without any thin portion such as the step portion 116. Therefore, the recording element substrate 101 is less likely to crack when pressure is applied. Furthermore, compared to the first embodiment, this is advantageous in reducing the dimensions of the recording element substrate 101 to reduce costs and save space.

[0042] Furthermore, the terminals 113 are positioned between the end of the support substrate 110 and the ejection port forming member 111. More specifically, the terminals 113 are positioned between the end face 117, which is the heated portion (predetermined portion), and the ejection port forming member 111. This arrangement allows a sufficient distance to be maintained between the end face 117 and the ejection port forming member 111, further improving the effect of suppressing damage to the ejection port 115 due to heat. The end surface 117 and the terminal 113, which are the heating parts, are provided at both ends of the support substrate 110. In the process shown in FIG. 9(a) to FIG. 9(e), the terminal 113 at one end is abutted against the lead wiring part 122 of the electric wiring substrate 102, and the terminal 113 at the other end is abutted against the lead wiring part 122 of another electric wiring substrate 102. The terminals 113 at both ends may be joined to the lead wiring part 122 at the same time. In this case, a heating tool 200 and a pressure tool 201 are disposed at each end. The end surface 117 at both ends of the support substrate 110 are clamped by the two heating tools 200. Also, after the terminal 113 at one end is joined to the lead wiring part 122, the terminal 113 at the other end may be joined to the lead wiring part 122. In this case, only one heating tool 200 and one pressure tool 201 may be used.

[0043] (Third embodiment) 10 is a diagram for explaining a manufacturing method of a liquid ejection head according to a third embodiment of the present invention. The manufacturing method of a liquid ejection head according to this embodiment includes a bonding process for bonding the lead wiring portion 122 of the electric wiring board 102 to the terminal 113 of the recording element board 101, but the portion to be heated (predetermined portion) is different from that of the first embodiment. The recording element substrate 101 has a support substrate 110, an ejection port forming member 111, and terminals 113. The ejection port forming member 111 and the terminals 113 are the same as those described in the first embodiment. The end portion of the support substrate 110 has a tapered surface 118 that is thinner toward the end portion instead of the step portion 116, and in this respect, it differs from the first embodiment.

[0044] The tapered surface 118 is an example of a predetermined portion to be heated when the terminal 113 and the lead wiring portion 112 are joined. The tapered surface 118 is located at both ends of the support substrate 110 in the longitudinal direction. The thickness of the tapered surface 118 is thinner than the thickness of the terminal 113. The distance d between the heated surface (heating portion) of the tapered surface 118 and the terminal 113 is shorter than the distance D between the heating portion of the tapered surface 118 and the discharge port forming member 111. The tapered surface 118 is closer to the terminal 113 than the discharge port forming member 111. The tapered surface 118 can be formed by anisotropic etching, similar to the step portion 116.

[0045] In the manufacturing method of this embodiment, the terminals 113 and the lead wiring portions 112 are joined in the same manner as in Figures 1(a) to 1(e). After this joining step, the sealing step and hardening step described in the first embodiment are carried out to obtain the liquid ejection head 100 shown in Figure 2(a). The method for manufacturing a liquid ejection head according to this embodiment also provides the same effects as those of the first embodiment. [Explanation of symbols]

[0046] 101 Recording element substrate 102 Electrical wiring board 110 Support substrate 110a Support surface 111 Discharge port forming member 113 Terminal 122 Lead wiring section

Claims

1. A method for manufacturing a liquid ejection head, comprising: a recording element substrate for ejecting liquid; and an electric wiring substrate having a lead wiring portion on one surface thereof, the recording element substrate having an ejection port forming member having a plurality of ejection ports, a support substrate having a support surface for supporting the ejection port forming member, and a terminal formed on the support surface and electrically connected to the lead wiring portion, the method comprising the steps of: and applying pressure to the contact portion between the lead wiring portion and the terminal from the electric wiring board side while heating a predetermined portion of the support substrate in a state in which the lead wiring portion is in contact with the terminal. A method for manufacturing a liquid ejection head, wherein the distance between the predetermined portion and the terminal is shorter than the distance between the predetermined portion and the ejection port forming member.

2. The method for manufacturing a liquid ejection head according to claim 1 , wherein the predetermined portion is closer to the terminal than to the ejection port forming member.

3. 3. The method for manufacturing a liquid ejection head according to claim 1, wherein the terminal is located between the predetermined portion and the ejection port forming member.

4. 4. The method for manufacturing a liquid ejection head according to claim 3, wherein the thickness of the predetermined portion of the support substrate is thinner than the thickness of the portion of the support substrate where the terminals are formed.

5. 5. The method for manufacturing a liquid ejection head according to claim 4, wherein the predetermined portion is a step portion provided on a surface opposite to the support surface.

6. 5. The method for manufacturing a liquid ejection head according to claim 4, wherein the predetermined portion is formed of a tapered surface that is thinner toward an end portion in the longitudinal direction of the support substrate.

7. 7. The method for manufacturing a liquid ejection head according to claim 5, wherein the predetermined portion is formed by anisotropic etching.

8. the support substrate has a constant thickness at least in a portion from the terminal to an end portion in a longitudinal direction of the support substrate, The method for manufacturing a liquid ejection head according to claim 3 , wherein the predetermined portion is an end face of the end portion of the support substrate.

9. the predetermined portion is located at an end portion in a longitudinal direction of the support substrate, applying a constant load to a surface of the electric wiring board opposite to the one surface; The method for manufacturing a liquid ejection head according to claim 1 , wherein a width in the longitudinal direction of the region to which the load is applied is smaller than a width in the longitudinal direction of the terminal.

10. the electrical wiring board has a base film that covers the entire lead wiring portion, The method for manufacturing a liquid ejection head according to claim 1 , wherein the lead wiring portion and the terminal are bonded by a chip-on-film method.

11. a discharge port forming member in which a plurality of discharge ports for discharging liquid are formed; a support substrate having a support surface for supporting the ejection port forming member; a terminal formed on the support surface to which a lead wiring portion of an electric wiring board is electrically connected, the terminal is located between an end of the support substrate and the discharge port forming member, the end portion of the support substrate has a step portion on a surface opposite to the support surface, so that the thickness of the end portion of the support substrate is thinner than the thickness of a portion of the support substrate where the terminal is formed; a distance d between the step portion and the terminal is smaller than a distance D between the step portion and the ejection port forming member,

12. a discharge port forming member in which a plurality of discharge ports for discharging liquid are formed; a support substrate having a support surface for supporting the ejection port forming member; a terminal formed on the support surface to which a lead wiring portion of an electric wiring board is electrically connected, the terminal is located between an end of the support substrate and the discharge port forming member, the end portion of the support substrate has a tapered surface that is thinner toward the end portion, so that the thickness of the end portion of the support substrate is thinner than the thickness of a portion of the support substrate where the terminal is formed; a distance d between the tapered surface and the terminal is smaller than a distance D between the tapered surface and the discharge port forming member,

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