JP2022081996A - Liquid discharge head and manufacturing method of the same - Google Patents

Abstract

To provide a liquid discharge head which enables improvement of filling performance of a sealant even if the sealant has a relatively high viscosity while inhibiting unwanted spreading of the sealant which seals electric connection parts.SOLUTION: A liquid discharge head 10 includes: a recording element substrate 3 which discharges a liquid; an electric wiring substrate 5 electrically connected to the recording element substrate 3; a support member 2 having a recessed part 21 which houses the recording element substrate 3; and a sealant 8 which seals electric connection parts 31, 51 between the recording element substrate 3 and the electric wiring substrate 5. The support member 2 has protrusion parts 12 protruding from a bottom surface 23 of the recessed part 21. Each protrusion part 12 is arranged close to the electric connection parts 31, 51, and a cutout part 13 which is open on an upper surface and a side surface of the protrusion part 12 is formed at the protrusion part 12. An opening of the cutout part 13 on the side surface of the protrusion part 12 is oriented in a direction of an area, which is located adjacent to the electric connection parts 31, 51, of a gap between a side surface 24 of the recessed part 21 and the recording element substrate 3. The sealant 8 fills a space ranging from the inner side of the cutout part 13 to the area of the gap.SELECTED DRAWING: Figure 3

Description

The present invention relates to a liquid discharge head and a method for manufacturing the same.

A liquid ejection head having a recording element substrate that ejects a liquid such as ink and an electric wiring board that supplies an electric signal or electric power for ejecting the liquid to the recording element substrate is known. The recording element board and the electric wiring board are electrically connected by connecting the connection terminal of the recording element board and the inner lead of the electric wiring board, and the electric connection part is sealed to protect from liquid and external force. It is sealed with a stop material. It is preferable that the encapsulant does not come into contact with the side surface of the recording element substrate as much as possible so as not to apply an unfavorable external force to the recording element substrate due to expansion or contraction due to environmental change or the like. Patent Document 1 describes a technique of forming a wall portion in a gap between a recess of a support member accommodating a recording element substrate and a recording element substrate to prevent the sealing material from flowing into an unnecessary gap. ing.

JP-A-2015-223832

From the viewpoint of electrical reliability and productivity of the liquid discharge head, it is required to fill even small gaps with a sealing material reliably and promptly. However, although the technique described in Patent Document 1 can suppress unnecessary spread of the encapsulant, when a encapsulant having a relatively high viscosity is used, it is possible to fill the required gap with the encapsulant. Will take a lot of time.
Therefore, an object of the present invention is to provide a liquid discharge head that improves the filling property of a sealing material having a relatively high viscosity while suppressing unnecessary spread of the sealing material that seals the electrical connection portion. It is to provide the manufacturing method.

In order to achieve the above-mentioned object, the liquid discharge head of the present invention has a recording element substrate for discharging liquid, an electric wiring board electrically connected to the recording element substrate, and a recess for accommodating the recording element substrate. It has a support member and a sealing material for sealing the electrical connection between the recording element substrate and the electrical wiring board, the support member has a protrusion protruding from the bottom surface of the recess, and the protrusion is a recording. It is arranged close to the electrical connection provided at the end of the element substrate, and the protrusion has notches formed on the upper surface and the side surface of the protrusion, and the notch opens on the side surface of the protrusion. Is oriented toward the region of the gap between the side surface of the recess and the recording element substrate adjacent to the electrical connection portion, and the encapsulant is filled from the inside of the notch portion to the region of the gap.
Further, the method for manufacturing a liquid discharge head of the present invention includes a recording element substrate for discharging liquid, an electrical wiring substrate electrically connected to the recording element substrate, a support member having a recess for accommodating the recording element substrate, and recording. It has a sealing material that seals the electrical connection between the element substrate and the electrical wiring substrate, and the support member is formed at a position close to the electrical connection in the gap between the recess and the recording element substrate. It is a method of manufacturing a liquid discharge head having a protrusion protruding from the bottom surface of the above, in which a step of forming notches opening on the upper surface and side surfaces of the protrusion and a recording element substrate are housed in the recess. The recording element substrate is recessed in a step of forming the notch, including a step of injecting a sealing material into the notch and sealing the electrical connection after being electrically connected to the electrical wiring board. The notch is formed so that the opening of the notch on the side surface of the protrusion faces the region of the gap between the side surface of the recess and the recording element substrate facing the electrical connection portion. The step of injecting the encapsulant includes injecting the encapsulant so that the encapsulant flows from the inside of the notch into the region of the gap.

According to the present invention, it is possible to improve the filling property of a sealing material having a relatively high viscosity while suppressing unnecessary spread of the sealing material for sealing the electrical connection portion.

It is a perspective view of the liquid discharge head which concerns on one Embodiment. It is a top view of the support member which concerns on one Embodiment. It is an enlarged view of a part of the liquid discharge head which concerns on one Embodiment. It is a top view which shows each stage of the joining process which concerns on one Embodiment. It is a top view which shows each stage of the sealing process which concerns on one Embodiment.

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

FIG. 1 is a perspective view of a liquid discharge head according to an embodiment of the present invention.
The liquid ejection head 10 ejects a liquid (for example, four-color inks of cyan, magenta, yellow, and black) and records an image on a recording medium. The housing 1, the support member 2, and 2 It has two recording element substrates 3 and 4 and an electrical wiring substrate 5. The support member 2 is attached to the housing 1, and the recording element boards 3 and 4 and the electrical wiring board 5 are joined to the support member 2. The recording element substrates 3 and 4 include a first recording element substrate 3 that ejects black ink and a second recording element substrate 4 that ejects inks of other three colors. The electric wiring board 5 is electrically connected to the recording element boards 3 and 4 in order to supply an electric signal and electric power for discharging the liquid to the recording element boards 3 and 4. Liquid is supplied to the recording element substrates 3 and 4 from a liquid supply unit (not shown) connected to the housing 1 through the housing 1 and the support member 2, and the supplied liquid is used as an electric signal or an electric signal through the electric wiring board 5. When electric power is supplied, it is discharged from the recording element substrates 3 and 4.

FIG. 2 is a plan view of the support member of the present embodiment.
The support member 2 is formed on a joint surface 20 to which the electric wiring board 5 is joined, a first recess 21 formed on the joint surface 20 and accommodating the first recording element substrate 3, and also formed on the joint surface 20. It has a second recess 22 for accommodating the second recording element substrate 4. The recesses 21 and 22 accommodate the recording element boards 3 and 4 with the connection terminals 31 (see FIG. 3A) and the inner leads 51 of the electrical wiring board 5 (FIG. 3A). (See) is provided so that it is approximately the same height as. This makes it possible to improve the reliability of the electrical connection portion between the connection terminal 31 and the inner lead 51.
The support member 2 is formed by resin molding. In the present embodiment, as the resin material (modified polyphenylene ether) of the support member 2, a filler is mixed in an amount of 40% by mass for the purpose of improving the rigidity and bringing the coefficient of linear expansion closer to the coefficient of linear expansion of the recording element substrates 3 and 4. Is used.

Here, with reference to FIG. 3, a detailed configuration of the recess of the support member of the present embodiment will be described. The first concave portion accommodating the first recording element substrate and the second concave portion accommodating the second recording element substrate have substantially the same configuration. Therefore, in the following, only the configuration of the first recess will be described. FIG. 3A is an enlarged plan view showing a region surrounded by a broken line in FIG. 1, and FIG. 3B is an enlarged perspective view of a part of the support member of the present embodiment. FIG. 3 (c) is a cross-sectional view taken along the line AA of FIG. 3 (b). In addition, in FIG. 3A, the illustration of the sealing material for sealing the electrical connection portion is omitted for the sake of easy viewing.
The support member 2 is a protrusion protruding from the bottom surface 23 of a first recess (hereinafter, also simply referred to as “recess”) 21 that accommodates the first recording element substrate (hereinafter, also simply referred to as “recording element substrate”) 3. Has twelve. The protrusion 12 is arranged so as to face the end portion of the long side surface (second side surface) 3b of the rectangular recording element substrate 3 adjacent to the intersection portion 3c with the short side surface (first side surface) 3a. There is. At the end of the recording element substrate 3 adjacent to the short side surface 3a, an electrical connection portion between the connection terminal 31 of the recording element substrate 3 and the inner lead 51 of the electrical wiring board 5 is provided, and therefore, the protrusion 12 is provided. , Are arranged in close proximity to the electrical connection portions 31, 51.

Further, the protrusion 12 is formed with a notch 13 that opens on the upper surface and the side surface thereof. The opening of the notch 13 on the side surface of the protrusion 12 faces the direction of the intersection 3c between the short side surface 3a and the long side surface 3b of the recording element substrate 3, and therefore the short side surface 3a of the recording element substrate 3 and the short side surface 3a thereof. It faces the direction of the gap between the side surface 24 of the facing recess 21 and the side surface 24. The details will be described later, but the gap is filled with the first sealing material 8 for sealing the electrical connection portions 31 and 51 through the notch portion 13, and the notch portion 13 is the first seal. It is provided to give directivity to the flow of the stop member 8. Therefore, the cutout portion 13 is preferably formed so that the depth from the opening is larger than the width when viewed from the direction orthogonal to the bottom surface 23 of the recess 21, and as an example, the depth is 1.2 mm. The width is 0.7 mm. Further, the notch portion 13 has a bottom surface 14 continuous with the bottom surface 23 of the recess 21 in order to smooth the flow of the first sealing material 8. The bottom surface 14 may be flat, but in order to enhance the directivity of the flow of the encapsulant, as shown in FIG. 3 (c), the bottom surface 23 of the recess 21 toward the opening of the notch portion 13. It is preferable to incline so as to approach.

Next, with reference to FIGS. 4 and 5, in the method of manufacturing the liquid discharge head of the present embodiment, the electrical connection portion is sealed from the joining step of joining the recording element substrate and the electric wiring board to the support member. The process up to the sealing process will be described. 4 (a) to 4 (c) are plan views showing each stage of the joining process of the present embodiment, and FIGS. 5 (a) to 5 (d) are each stage of the sealing process of the present embodiment. It is a plan view which shows the figure, and it is the figure which corresponds to FIG. 3 (a). In the following, the description of the joining process and the sealing process relating to the second recording element substrate will be omitted, and only the joining process and the sealing process relating to the first recording element substrate will be described.

First, as shown in FIG. 4A, a support member 2 having a protrusion 12 having a notch 13 formed on the bottom surface 23 of the recess 21 is prepared. The support member 2 is also formed with a flow path 11 for supplying a liquid to the recording element substrate 3.
Next, as shown in FIG. 4B, the recording element substrate 3 is housed in the recess 21 and joined to the support member 2. Specifically, first, a thermosetting adhesive (not shown) is applied to the bottom surface 23 of the recess 21 along the peripheral edge of the opening of the flow path 11. Then, the position of the liquid supply path (not shown) formed on the recording element substrate 3 is aligned with the position of the flow path 11 of the support member 2, and the recording element substrate 3 is attached to the support member 2 while being heated.
Next, a thermosetting adhesive (not shown) different from the one to which the recording element substrate 3 is bonded is applied to the joint surface 20 of the support member 2, and the electric wiring board 5 is supported by heat crimping. Join to. Then, as shown in FIG. 4C, the connection terminal 31 of the recording element substrate 3 and the inner lead 51 of the electrical wiring board 5 are connected by heating ultrasonic bonding, and the recording element substrate 3 and the electrical wiring board 5 are connected to each other. Connect electrically.

Next, as shown in FIG. 5, the electrical connection portions 31, 51 thus formed are sealed with the first sealing material 8 and the second sealing material 9 in order to protect them from liquids and external forces.
Specifically, first, a first sealing material 8 made of a thermosetting resin is cut out from a needle (not shown) arranged in contact with the protrusion 12 at a position shown by a dotted line in the figure. Inject into 13. The injection amount at this time is larger than the minimum necessary amount as described later in order to surely fill the gap for sealing the electrical connection portions 31, 51 with the first sealing material 8. The quantity. The injected first encapsulant 8 flows along the shape of the notch 13 as shown by an arrow in FIG. 5A, and flows in a gap under the inner lead 51 (that is, the recording element substrate 3). (Gap between the short side surface 3a of the above and the side surface 24 of the recess 21 facing the short side surface 3a). Then, as shown in FIG. 5 (b), when the gap is almost filled with the first sealing material 8, as shown in FIG. 5 (c), the surplus first sealing material 8 is used. It flows into the periphery of the protrusion 12. In this way, the first sealing material 8 is filled from the inside of the notch portion 13 to the gap on the lower side of the inner lead 51, that is, to the gap facing the electrical connection portions 31, 51, and around the protrusion 12. It is also filled in the gaps between the two.
Then, as shown in FIG. 5D, a second sealing material 9 made of a thermosetting resin is applied so as to cover the inner lead 51 from above. Then, the support member 2 is held at a high temperature for a certain period of time, and the first encapsulant 8 and the second encapsulant 9 are thermally cured, so that the electrical connection portions 31 and 51 become the first encapsulant 8. It is sealed with the second sealing material 9.

As described above, in the present embodiment, the flow of the first sealing material 8 injected into the notch 13 is directed toward the gap for sealing the electrical connection portions 31, 51. It is possible to improve the filling property of the first sealing material 8 into the gap. Therefore, for example, as a sealing material for ensuring long-term reliability, a material having a relatively high viscosity has been found by the present inventors, but even such a sealing material having a relatively high viscosity has been found. , The gaps for sealing the electrical connection portions 31, 51 can be reliably and quickly filled. Further, in the present embodiment, since the protrusion 12 is provided, it is possible to prevent the first sealing material 8 injected into the notch 13 from flowing in the direction of the long side surface 3b of the recording element substrate 3. Therefore, it is possible to suppress unnecessary spreading of the first sealing material 8.
In the present embodiment, when the first sealing material 8 is injected into the notch portion 13, the tip of the needle is brought into contact with the protrusion portion 12, but it is not always necessary to bring them into contact with each other. However, in order to allow the first sealing material 8 discharged from the needle to efficiently flow into the notch 13 without overflowing around the notch 13, the distance between the tip of the needle and the protrusion 12 (protrusion). The distance between the two in the height direction of the portion 12) is preferably as short as possible.

Finally, a method of setting the injection amount of the first encapsulant 8 will be described with reference to a specific example.
The injection amount of the first sealing material 8 is the minimum required filling amount calculated based on the volume of the gap for sealing the electrical connection portions 31, 51, and the sealing material is surely filled in the gap. It is determined as the sum of the extra amount to be used. The filling amount is calculated from the value obtained by multiplying the volume of the gap calculated from the nominal size by the correction coefficient considering the dimensional tolerance (corrected volume) and the specific gravity (density) of the sealing material to be used, and the excess amount is used. It is calculated from the process capacity such as the variation in the coating amount of the sealing material.
For example, the nominal dimensions of the gap for sealing the electrical connection portions 31, 51 are set to 0.6 mm in width, 2.2 mm in length, and 0.6 mm in depth, and the correction coefficient considering the dimensional tolerance is 1.2. Then, the corrected volume becomes (0.6 mm × 2.2 mm × 0.6 mm) × 1.2 = 0.95 mm ³ . Further, assuming that the density of the encapsulant used is 1.4 g / cm ² , the minimum required filling amount for one electric connection portion is 1.33 mg. However, in the present embodiment, since two notches 13 are provided as injection points for one electrical connection part 31, 51, the filling amount per place is 0.66 mg. Then, assuming that the excess amount at each injection site is 1.4 mg, the injection amount of the first encapsulant 8 per injection site is set to 0.66 mg + 1.4 mg = 2.06 mg.

2 Support member 3 First recording element board 5 Electrical wiring board 8 First encapsulant 12 Protrusion 13 Notch 21 Recess

Claims (9)

A recording element substrate for discharging liquid, an electric wiring board electrically connected to the recording element substrate, a support member having a recess for accommodating the recording element substrate, and the recording element substrate and the electric wiring board. A liquid discharge head having a sealing material for sealing an electrical connection.
The support member has a protrusion protruding from the bottom surface of the recess, and the protrusion is arranged in close proximity to the electrical connection provided at the end of the recording element substrate.
A notch that opens on the upper surface and the side surface of the protrusion is formed in the protrusion, and the opening of the notch on the side surface of the protrusion is a gap between the side surface of the recess and the recording element substrate. Of these, it faces the direction of the area adjacent to the electrical connection.
The liquid discharge head is filled with the sealing material from the inside of the notch portion to the region of the gap. The recording element substrate has a first side surface adjacent to the end portion provided with the electrical connection portion and a second side surface intersecting with the first side surface, and the region is the recording element. The liquid discharge head according to claim 1, which is a region between the first side surface of the substrate and the side surface of the recess facing the first side surface. The liquid discharge head according to claim 2, wherein the protrusion is arranged so as to face an end of the second side surface adjacent to an intersection with the first side surface. The liquid discharge head according to claim 3, wherein the opening of the notch portion faces the direction of the intersection. The liquid discharge head according to any one of claims 1 to 4, wherein the depth of the notch from the opening is larger than the width of the notch when viewed from a direction orthogonal to the bottom surface of the recess. .. The liquid discharge head according to any one of claims 1 to 5, wherein the cutout portion has a bottom surface continuous with the bottom surface of the recess. The liquid discharge head according to claim 6, wherein the bottom surface of the notch portion is inclined toward the opening of the notch portion so as to approach the bottom surface of the recess. A recording element substrate for discharging liquid, an electric wiring board electrically connected to the recording element substrate, a support member having a recess for accommodating the recording element substrate, and the recording element substrate and the electric wiring board. It has a sealing material for sealing an electrical connection portion, the support member has a protrusion protruding from the bottom surface of the recess, and the protrusion is provided at an end portion of the recording element substrate. A method for manufacturing a liquid discharge head, which is arranged in close proximity to the electrical connection portion.
A step of forming notches in the protrusions that open on the upper surface and side surfaces of the protrusions, and
The process includes a step of accommodating the recording element substrate in the recess and electrically connecting to the electrical wiring board, then injecting the sealing material into the notch portion and sealing the electrical connection portion.
In the step of forming the notch, the opening of the notch on the side surface of the protrusion is a gap between the side surface of the recess and the recording element substrate in a state where the recording element substrate is housed in the recess. Including forming the notch so as to face the region facing the electrical connection.
A method for manufacturing a liquid discharge head, wherein the step of injecting the encapsulant material comprises injecting the encapsulant material so that the encapsulant material flows from the inside of the notch portion into the region of the gap. The liquid discharge head according to claim 8, wherein the step of injecting the sealing material comprises injecting the sealing material while bringing the tip of the needle for discharging the sealing material into contact with the protrusion. Production method.

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