Liquid ejection head and method of manufacturing the same

Abstract

To provide a liquid discharge head configured so that an electric connection part and a non-electric connection part can perform sealing in accordance with a purpose, and a manufacturing method for a liquid discharge head.SOLUTION: One end part at one side provided with an electric connection part of a recording element substrate is formed in a stepped shape.SELECTED DRAWING: Figure 2

Description

[Technical Field]

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

[0002] The support member and recording element substrate that make up the liquid ejection head are joined by applying an adhesive to the support member and then aligning and mounting the recording element substrate. The electrical wiring board and recording element substrate are then electrically connected by wire bonding using gold (Au) wires. The wire-bonded electrical connections are protected by sealing with a sealant. When sealing the electrical connections, it is necessary to ensure the electrical quality of the liquid ejection head by thoroughly filling the sealant into even the smallest details, such as gaps in the electrical connections.

[0003] The sealant is also filled into non-electrically connected portions of the recording element substrate, to form a sealed space when the cap member that vacuum wipes the ejection surface comes into contact with the non-electrically connected portions, and the sealant is filled to a predetermined height to increase the degree of adhesion with the cap member.

[0004] In this way, both the electrically connected portions and the non-electrically connected portions are sealed with a sealant, but the purposes are different. By varying the fluidity of the sealant in the portions with different sealing purposes, a good sealing state can be achieved. In other words, high fluidity is required to reliably fill the sealant into small spaces such as gaps. Furthermore, filling the sealant to a specified height does not require high fluidity, but rather requires that a specified amount of sealant remain in a specified position.

[0005] When the sealing purposes are different in this way, typically different sealants are used to seal each part according to the purpose, but when different sealants are used according to the purpose, there is a concern that costs will increase due to the increased number of types of materials.

[0006] Patent Document 1 describes a method for dicing a wafer, in which a half-cut cut line is formed by down-cutting in the forward direction, and the remaining work portion and dicing tape are fully cut by up-cutting in the return direction. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-302228 Summary of the Invention [Problem to be solved by the invention]

[0008] The fluidity of the sealant is affected by the shape of the sealing portion. In particular, the shape of the end of the recording element substrate where the electrical connection portion and non-electrical connection portion are provided has a significant effect on the fluidity of the sealant. In the cutting method of Patent Document 1, the cross section of each cut portion has an end shape consisting of a single surface spanning the entire width and thickness of the recording element substrate. Therefore, the fluidity of the sealant is the same in each cut portion, and it is not possible to perform sealing with different fluidities tailored to the purpose.

[0009] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a liquid ejection head that can seal electrically connected portions and non-electrically connected portions according to the purpose, and a method for manufacturing such a liquid ejection head. [Means for solving the problem]

[0010] Therefore, the method for manufacturing a liquid ejection head of the present invention includes a cutting step of cutting out a recording element substrate from a wafer by a cutting means having a predetermined thickness, a connecting step of connecting an electrical connection portion provided on a part of the recording element substrate to an electrical wiring board by wire bonding, and a connecting portion that connects the electrical connection portion connected in the connecting step to the electrical wiring board and at least a part of the periphery of the recording element substrate. No. 1a first sealing step of sealing with a sealant, wherein the cutting step includes the following steps: a first cutting step of moving the cutting means to a predetermined depth in the thickness direction of the wafer to make an incision in the end of the recording element substrate where the electrical connection portion is provided, a second step of changing the relative position of the cutting means and the wafer within the thickness of the cutting means in the thickness direction of the cutting means and in a direction away from the electrical connection portion, and a third step of cutting the recording element substrate at the position moved in the second step. [Effects of the Invention]

[0011] According to the present invention, it is possible to provide a liquid ejection head and a method for manufacturing a liquid ejection head that can seal electrically connected portions and non-electrically connected portions with different fluidities depending on the purpose. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 2 is a schematic diagram showing a liquid ejection head. [Figure 2] FIG. 2 is a diagram showing a recording element substrate. [Figure 3] FIG. 3 is a diagram showing a recording element substrate and a first support member. [Figure 4] FIG. 2 is a plan view showing a first support member 1 and a second support member. [Figure 5] FIG. 10 is a diagram showing the process of two-stage offset cutting. [Figure 6] FIG. 10 is a cross-sectional view of the recording element substrate cut along a two-stage offset cut. [Figure 7] 1A to 1C are diagrams showing the full cutting process in order of steps. [Figure 8] FIG. 4 is a cross-sectional view of the recording element substrate cut by full cutting. [Figure 9] FIG. 2 is a diagram showing recording element substrates arranged on a wafer. [Figure 10] FIG. 10 is a diagram showing a state in which the periphery of the recording element substrate is sealed with a first sealant. [Figure 11]5A to 5C are views showing the process of joining the recording element substrate to the first support member in the order of steps. [Figure 12] FIG. 10 is a diagram showing a first support member to which an electric wiring member is joined, and a second support member joined to the electric wiring member. [Figure 13] FIG. 10 is a diagram showing a recording element substrate in which a sealant is applied to the periphery other than the end portion on the electrical connection side. [Figure 14] FIG. 10 is a diagram showing a state in which a first sealant is injected with a needle. [Figure 15] FIG. 10 is a diagram showing a recording element substrate with a sealant applied around the periphery. [Figure 16] FIG. 10 is a diagram showing the first sealant flowing under the gold wires. [Figure 17] FIG. 10 is a diagram showing a state in which a second sealant is applied after a first sealant is applied. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0014] 1 is a schematic diagram showing a liquid ejection head 10 to which this embodiment can be applied. The liquid ejection head 10 includes a recording element substrate 4, an electric wiring substrate 5 electrically connected to the recording element substrate 4, a second support member 2 adhered to the electric wiring substrate 5, and a first support member 1 supporting the recording element substrate 4, the electric wiring substrate 5, and the second support member 2. The periphery of the recording element substrate 4 is sealed with a first sealant 8, and the connection portion between the recording element substrate 4 and the electric wiring substrate 5 is sealed with sealants (the first sealant 8 and the second sealant 9).

[0015] The recording element substrate 4 has a plurality of ejection ports (not shown), and ejects liquid supplied from a liquid supply unit (not shown) to the recording element substrate 4 through the first support member 1 from the ejection ports by driving the drive elements based on an electric signal from the electric wiring substrate 5. The electric wiring substrate 5 is sandwiched between the first support member 1 and the second support member 2 and bonded thereto.

[0016] FIG. 2 is a diagram showing a recording element substrate 4 according to this embodiment. The recording element substrate 4 has an electrical connection portion 40 (connection terminal) electrically connected to the electrical wiring substrate 5 and a non-electrical connection portion 41 that is not connected to other components. The end of the recording element substrate 4 on the side where the electrical connection portion 40 is provided (near the electrical connection portion 40) is a stepped end portion 42. The stepped end portion 42 is formed at a position recessed by one step from the surface of the recording element substrate 4 (the surface where the electrical connection portion 40 is provided), and this surface extends across the entire area of the recording element substrate 4 in the direction perpendicular to the plane of FIG. 2 and continues to the end of the recording element substrate 4 to the right of the plane of FIG. 2. This end portion forms a vertical surface. The end of the recording element substrate 4 on the side where the non-electrical connection portion 41 is provided is a vertical surface end portion 43 without a step. Note that the non-electrical connection portion 41 here refers to the end of the recording element substrate 4 where the electrical connection portion 40 is not provided.

[0017] Fig. 3(a) is a diagram showing the first support member 1, and Fig. 3(b) is a diagram showing the first support member 1 to which the recording element substrate 4 is adhered. The first support member 1 is provided with a supply port 11 that supplies liquid to the recording element substrate 4, and the liquid is supplied to the recording element substrate 4 through the supply port 11 (see Fig. 3(a)). After an adhesive is applied to the first support member 1, the recording element substrate 4 is aligned with the supply port 11, and then mounted on the first support member 1 and adhesively fixed (see Fig. 3(b)).

[0018] FIG. 4 is a plan view showing a first support member 1 to which a recording element substrate 4 and an electrical wiring substrate 5 are bonded, and a second support member 2 bonded to the electrical wiring substrate 5. The electrical wiring substrate 5 is bonded to the first support member 1 with a different adhesive than the adhesive used to bond the recording element substrate 4. The second support member 2 is bonded to the electrical wiring substrate 5 using the same adhesive 7 as the electrical wiring substrate 5 bonded to the first support member 1. A wide range of ceramic materials, such as Al2O3, or resin materials can be used for the first support member 1 and the second support member 2. In this embodiment, a ceramic material is used. The leads 51 of the electrical wiring substrate 5 and the electrical connection portions 40 of the recording element substrate 4 are connected by wire bonding using gold (Au) wires 61.

[0019] In this embodiment, when separating the wafer 20 by dicing, cutting is performed using two methods: two-stage offset cutting and one-stage cutting. Below, a cutting process for separating the wafer 20, on which a plurality of recording element substrates 4 are arranged, by dicing will be described.

[0020] FIGS. 5(a) to 5(d) are diagrams showing the process of two-stage offset cutting in this embodiment in order of steps. To cut the wafer 20, the wafer 20 mounted on the dicing tape 26 is cut into individual pieces using a blade disk 23 rotating at high speed. During cutting, ultrapure water is sprayed on the blade disk 23 and the wafer 20. In two-stage offset cutting, as shown in FIG. 5(a), the blade disk 23 is first moved to half the thickness (predetermined depth) of the recording element substrate 4, and the recording element substrate 4 is half-cut. The result of the half-cut is shown in FIG. 5(b). Then, by changing the relative positions of the blade disk 23 and the wafer 20, the position of the blade disk 23 relative to the wafer 20 is changed in the direction of arrow A (thickness direction of the blade disk) (see FIG. 5(c)). Specifically, the relative position of the blade disk 23 is changed within the range of the blade disk thickness. The recording element substrate 4 is cut at the changed position with the blade disk 23, and the blade disk 23 makes a cut to a depth that will result in a 0.05 mm cut in the dicing tape 26. In this way, the recording element substrate 4 is cut. The result of cutting the recording element substrate 4 is as shown in Figure 5(d).

[0021] 6 is a cross-sectional view of the recording element substrate 4 cut by a two-stage offset cut. The recording element substrates 4 are lined up on the wafer 20, and the recording element substrates 4 are separated by cutting between them. When cutting by a two-stage offset cut in the manner described above, the end of the recording element substrate 4 on the side where the electrical connection portion 40 of the recording element substrate 4 is provided becomes a stepped end portion 42, and the end of the recording element substrate 4 on the side where the non-electrical connection portion 41 is provided becomes a vertical surface end portion 43 without a step.

[0022] 7(a) and (b) are diagrams showing the full-cut process in this embodiment in order of steps. In full-cutting, as shown in FIG. 7(a), the recording element substrate 4 is cut by the blade disk 23, and the blade disk 23 is moved to a depth where a 0.05 mm deep cut is made in the dicing tape 26. In this way, full-cutting cuts the recording element substrate 4 in one step. The result of full-cutting is shown in FIG. 7(b).

[0023] 8 is a cross-sectional view of the full-cut recording element substrate 4. When full-cutting is performed, the ends of the continuously arranged recording element substrates 4 all become vertical end surfaces 43 without steps.

[0024] In this embodiment, the wafer 20 is cut by selectively using two-stage offset cutting or full cutting depending on the cutting position relative to the recording element substrate 4.

[0025] FIG. 9(a) is an enlarged view of a portion of a wafer 20 on which recording element substrates 4 are arranged, and FIG. 9(b) is a view showing a cutting process for dicing the wafer 20 on which a plurality of recording element substrates 4 are arranged. In this embodiment, as shown in FIG. 9(a), the recording element substrates 4 are arranged on the wafer 20, and the electrical connection portion 40 is provided on the right side of the recording element substrate 4 in the drawing. Therefore, in this embodiment, as shown in FIG. 9(b), cutting in the direction of arrow B is performed using a two-stage offset cut, and cutting in the direction of arrow C, which intersects with the direction of arrow B, is performed using a full cut. By performing the cutting in the direction of arrow B using a two-stage offset cut, the end of the recording element substrate 4 on the electrical connection portion 40 side becomes a stepped end 42, and the end of the recording element substrate 4 on the side where the non-electrical connection portion 41 is provided (ends other than the one end) becomes a stepless vertical surface end (one-surface end) 43.

[0026] Figure 10 is a diagram showing a state in which a recording element substrate 4 and an electrical wiring substrate 5 are joined to a first support member 1, a second support member 2 is joined to the electrical wiring substrate 5, and the periphery of the recording element substrate 4 is sealed with a first sealant 8.

[0027] In this embodiment, the first sealant 8 is poured under the gold (Au) wire 61 by utilizing the ridge line of the step portion of the stepped end portion 42 created by cutting with two offset cuts. In order to pour the first sealant 8 under the gold (Au) wire 61, it is preferable to set the step width W to 0.01 mm to 0.05 mm (see FIG. 6). The maximum width of 0.05 mm is a value calculated from the fact that the width of the cutting line is a maximum of 0.15 mm.

[0028] The first sealant 8 contains filler particles with a diameter of 0.025 mm, and the step depth D (see FIG. 6) is set so that the first sealant 8 can flow into the gap between the recording element substrate 4 and the gold (Au) wire 61 even if the filler particles overlap. The gap between the recording element substrate 4 and the gold (Au) wire 61 required for this purpose is set to 0.15 mm, which is five times the maximum filler dimension (0.03 mm). It is preferable to set this gap appropriately. When the gap before cutting is 0.03 mm and the minimum gap is set to twice the maximum filler dimension (0.03 mm), it is preferable to set the cutting depth D to 0.03 mm to 0.10 mm. The step width and cutting depth are not limited to these values and are preferably set appropriately depending on the viscosity of the sealant and the ambient temperature.

[0029] A method for manufacturing the liquid ejection head 10 will now be described.

[0030] 11(a) to 11(c) are diagrams showing the order of steps for bonding the recording element substrate 4 to the first support member 1. A thermosetting adhesive 7 is applied (see FIG. 11(b)) to the periphery of the supply port 11 of the first support member 1 (see FIG. 11(a)), which has the supply port 11 formed therein. Thereafter, the recording element substrate 4 cut out from the wafer 20 is aligned with the supply port 11 of the first support member 1 and bonded to the first support member 1 while being heated with the adhesive 7 (see FIG. 11(c)).

[0031] FIG. 12(a) shows an electric wiring board 5 bonded to a first support member 1, and FIG. 12(b) shows a second support member 2 bonded to the first support member 1 in the state shown in FIG. 12(a). The electric wiring board 5 is bonded to the first support member 1, to which the recording element substrate 4 has been bonded, by thermocompression bonding using a thermosetting adhesive (not shown), as shown in FIG. 12(a). Then, the connection terminals 40 provided on the recording element substrate 4 and the leads 51 of the electric wiring board 5 are wire-bonded using gold (Au) wires 61. Then, as shown in FIG. 12(b), the second support member 2 is bonded to the electrically connected electric wiring board 5 by compression bonding using the same adhesive as used to bond the first support member 1 and the electric wiring board 5. At this time, the second support member 2 is bonded so that the recording element substrate 4 is positioned within the opening of the second support member 2.

[0032] 13(a) and 13(b) are diagrams showing the application of the first sealant 8 to the periphery of the recording element substrate 4, excluding the end portion on the electrical connection portion 40 side. FIGS. 14(a) to 14(c) are diagrams showing the injection of the first sealant 8 with a needle 12, showing a partial cross section of FIG. 13(b). As shown in FIG. 13(a), the first sealant 8 is injected into the periphery, including the non-electrically connected portion, excluding the end portion on the electrical connection portion 40 side, while moving the needle as shown by arrow 44 (see FIG. 13(b)). This seals the gap between the recording element substrate and the edge of the opening of the second support member 2 with the sealant. As shown in FIG. 14, the liquid level of the first sealant 8 injected from the needle 12 rises, and a meniscus forms between the edge portion of the recording element substrate 4 and the edge portion of the second support member 2, allowing the first sealant 8 to fill to the same height as the recording element substrate 4.

[0033] Figure 15(a) and (b) show the 1 sealant 8 15(a) shows how the first sealant 8 is applied to both side ends of the electrical connection portion 40 of the recording element substrate 4. As shown in FIG. 15(a), the needle 12 is positioned at position 46 on both ends of the side end of the electrical connection portion 40, and the first sealant 8 is applied. At this time, the needle 12 is applied at position 46 without moving. The applied first sealant 8 flows along the ridge of the step portion of the stepped end 42 and flows under the gold (Au) wire 61 (see FIG. 15(b)).

[0034] 16(a) to 16(d) are diagrams showing how the first sealant 8 applied to position 46 flows under the gold (Au) wire 61. As shown in FIG. 16(a), the first sealant 8 applied to position 46 starts to flow along the ridge of the step of the stepped end 42, as shown in FIG. 16(b). The gap between the step of the stepped end 42 and the gold (Au) wire 61 is 0.15 mm, and the first sealant 8 flows along the ridge of the step from both ends of the end on the electrical connection portion 40 side toward the center due to capillary action (see FIG. 16(b)). Then, as shown in FIG. 16(c), the first sealant 8 joins at approximately the center of the end on the electrical connection portion 40 side. Finally, as shown in FIG. 16(d), the lower part of the gold (Au) wire 61 at the end on the electrical connection portion 40 side is sealed with the first sealant 8. The lower portion of the gold (Au) wire 61 at the end on the electrical connection portion 40 side is sealed with the first sealant 8, so that the periphery of the recording element substrate 4 is sealed with the first sealant 8.

[0035] In this embodiment, the periphery of the recording element substrate 4 is sealed with the first sealant 8, but this is not limiting, and a configuration is also possible in which the lower part of the gold (Au) wire 61 at the end on the electrical connection portion 40 side and at least a part of the periphery of the recording element substrate 4 are sealed with the first sealant 8. Furthermore, in this embodiment, the first sealant 8 is applied to positions 46 at both ends of the end on the electrical connection portion 40 side, but this is not limiting, and the first sealant 8 may be applied to either position 46 at the end on the electrical connection portion 40 side. In this case, an amount of the first sealant 8 that reaches the other position 46 is applied.

[0036] 17 is a diagram showing a state in which the second sealant 9 is applied after the application of the first sealant 8. After the application of the first sealant 8, the second sealant 9 is applied onto the gold (Au) wires 61 in order to protect the gold (Au) wires 61 and the electrical connection parts 40 from liquids such as ink and external forces. After the application of the first sealant 8 and the second sealant 9 is completed, the first support member 1 is left in a high-temperature environment for a certain period of time to thermally cure the adhesive 7, the first sealant 8, and the second sealant 9. The first sealant 8 and the second sealant 9 may be the same type of sealant.

[0037] In this way, one end of the recording element substrate where the electrical connection section is provided is formed in a stepped shape, which makes it possible to provide a liquid ejection head and a method for manufacturing a liquid ejection head that can seal the electrical connection section and the non-electrical connection section with different fluidities depending on the purpose. [Explanation of symbols]

[0038] 1 first support member 2 Second support member 4. Recording element board 5 Electrical wiring board 8. First sealant 9 Second sealant 10 Liquid ejection head 23 blade disc

Claims

1. a cutting step of cutting out recording element substrates from the wafer using a cutting means having a predetermined thickness; a connecting step of connecting an electrical connection portion provided on a part of the recording element substrate to an electrical wiring board by wire bonding; a first sealing step of sealing, with a first sealant, the connection portion that connects the electrical connection portion connected in the connecting step to the electrical wiring board and at least a part of the periphery of the recording element substrate; A method for manufacturing a liquid ejection head, comprising: The cutting step includes a first cutting step: a first step of cutting an end portion of the recording element substrate, on which the electrical connection portion is provided, to a predetermined depth in a thickness direction of the wafer by moving the cutting means; a second step of changing a relative position between the cutting means and the wafer within a range of the thickness of the cutting means in a thickness direction of the cutting means and in a direction away from the electrical connection portion; a third step of cutting the recording element substrate at the position to which the recording element substrate was moved in the second step; A method for manufacturing a liquid ejection head, comprising:

2. the cutting step includes a fourth step as a second cutting step of cutting the end of the recording element substrate by moving the cutting means in the thickness direction of the wafer, 2. The method for manufacturing a liquid ejection head according to claim 1, wherein the cutting process includes a first cutting process for cutting the wafer in a first direction and a second cutting process for cutting the wafer in a second direction intersecting the first direction.

3. A method for manufacturing a liquid ejection head as described in claim 1 or 2, characterized in that in the first sealing process, the connection portion is sealed by applying the first sealant to both side ends of the recording element substrate that sandwich the connection portion.

4. A method for manufacturing a liquid ejection head as described in claim 1 or 2, characterized in that in sealing the connection portion in the first sealing process, the connection portion is sealed by applying the first sealant to either one of the two side ends of the recording element substrate that sandwich the connection portion.

5. a first supporting step of supporting the recording element substrate with a first supporting member; A method for manufacturing a liquid ejection head as described in any one of claims 1 to 4, further comprising a second support process in which the electrical wiring board is supported by being sandwiched between the first support member and the second support member, and the recording element board is positioned within an opening provided in the second support member.

6. A method for manufacturing a liquid ejection head as described in claim 5, characterized in that in the first sealing process, the periphery of the recording element substrate is sealed by sealing the connection portion and the space between the recording element substrate and the edge of the opening within the opening with the first sealant.

7. A method for manufacturing a liquid ejection head as described in Claim 6, wherein the first sealant is filled at the ends other than the one end in a direction perpendicular to the surface of the recording element substrate to the same height as the ends.

8. A method for manufacturing a liquid ejection head as described in any one of claims 1 to 7, further comprising a second sealing process for sealing the wire used for the wire bonding connection by applying a second sealant onto the connection portion sealed in the first sealing process.

9. In the first supporting step, the recording element substrate is supported by the first supporting member via an adhesive; 6. The method for manufacturing a liquid ejection head according to claim 5, wherein in the second supporting step, the electric wiring board is supported by being sandwiched between the first supporting member and the second supporting member via an adhesive.

10. a recording element substrate that ejects liquid; an electric wiring board electrically connected to an electric connection portion provided on a part of the recording element substrate; a first support member for supporting the recording element substrate; a second support member for supporting the electrical wiring board; a sealant for sealing a connection portion where the recording element substrate and the electric wiring substrate are connected by wire bonding; A liquid ejection head comprising: the electrical connection portion is provided in the vicinity of one end of the recording element substrate, the one end portion has a stepped shape with a predetermined step, A liquid ejection head, characterized in that the end portions of the recording element substrate other than the one end portion have end faces without steps.

11. A liquid ejection head as described in Claim 10, wherein at least a portion of the periphery of the recording element substrate is sealed with the sealant.

12. The electrical wiring board is supported by being sandwiched between the first support member and the second support member, and the recording element board is positioned within an opening provided in the second support member, The liquid ejection head according to claim 10 , wherein a gap between the recording element substrate and an edge of the opening is sealed with a first sealant.

13. A liquid ejection head as described in Claim 11, wherein at the ends other than the one end, the sealant is filled to the same height as the end in a direction perpendicular to the surface of the recording element substrate.

Images