JP4235418B2 - Inkjet head recording element unit - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a recording element unit of the ink jet head.
[0002]
[Prior art]
First, a conventional technique will be described with reference to FIGS.
[0003]
7 and 8 show a bubble jet (R) type ink jet head of a side shooter type that ejects droplets in a direction substantially perpendicular to the heater substrate.
[0004]
FIG. 7 is an exploded perspective view illustrating the inkjet head, and FIG. 8 is a diagram illustrating the inkjet head.
[0005]
H1001 is an inkjet head, H1002 is a recording element unit, H1003 is an ink supply unit, H1100 is a first recording element substrate that is one of the recording element substrates, and H1101 is a second recording that is one of the recording element substrates. Element substrate, H1104 is a nozzle row, H1200 is a first plate forming a plate, H1250 and H1251 are ink supply ports, H1202 is a plate assembly (element substrate) which is a plate, H1300 is an electrical wiring tape, and H1302 is , H1307 is a first sealant, H1308 is a second sealant, H1400 is a second plate forming a plate, H1500 is an ink supply member, and H1600 is a flow path formation. H1700 is a filter, H1800 is a seal rubber, H2000 is a tongue Holder, H2200 electric contact substrate, H2300 is joint rubber, H2400 is bis.
[0006]
The inkjet head H1001 includes a recording element unit H1002, an ink supply unit H1003, and a tank holder H2000.
[0007]
As shown in the exploded perspective view of FIG. 7, the recording element unit H1002 includes a first recording element substrate H1100, a second recording element substrate H1101, a first plate H1200, an electric wiring tape H1300, and an electric contact substrate H2200. , The second plate H1400.
[0008]
The ink supply unit H1003 includes an ink supply member H1500, a flow path forming member H1600, a filter H1700, a seal rubber H1800, and a joint rubber H2300.
[0009]
Next, the recording element unit H1002 will be described.
[0010]
The recording element unit H1002 includes (1) formation of a plate assembly H1202 by joining the first plate H1200 and the second plate H1400, (2) mounting of the recording element substrates H1100 and H1101 to the plate assembly H1202, and (3). ▼ Electrical bonding of the electrical wiring tape H1300 and the recording element substrates H1100 and H1101; (4) Sealing of the electrical wiring tape H1300 lamination and the electrical connection portion of the recording element substrates H1100 and H1101; The wiring tape H1300 and the electrical contact substrate H2200 are mounted in this order.
[0011]
The first plate H1200 has ink supply ports H1250 for supplying black ink to the first recording element substrate H1100 and inks for supplying cyan, magenta, and yellow ink to the second recording element substrate H1101. A supply port 1251 is formed.
[0012]
The second plate H1400 is joined to the first plate H1200 so that the ink supply ports H1250 and H1251 are exposed (1) A plate assembly H1202 formed by joining the first plate H1200 and the second plate H1400. Formation).
[0013]
Next, referring to FIG. 9, (2) mounting of the recording element substrates H1100 and H1101 to the plate assembly H1202, (3) stacking of the electric wiring tape H1300 and electrical connection between the recording element substrates H1100 and H1101, (4) (2) The lamination of the electric wiring tape H1300 and sealing of the electric joint portion between the recording element substrates H1100 and H1101, etc., and (5) the bonding of the electric wiring tape H1300 and the electric contact substrate H2200 will be described.
[0014]
FIG. 9 is an enlarged view around the recording element substrate for explaining the ink jet head.
[0015]
H1102 is a connection pad provided with an Au stud bump (hereinafter also referred to as a stud bump) on the top, and H13050 and H13051 are device holes.
[0016]
The first recording element substrate H1100 and the second recording element substrate H1101 are bonded and fixed to the surface of the first plate H1200 with high positional accuracy. (2) Mounting of the recording element substrates H1100 and H1101 to the plate assembly H1202 ).
[0017]
The recording element substrates H1100 and H1101 having the nozzle rows H1104 have a known structure as a side shooter type ink jet substrate, and an ink channel (not shown) comprising a long groove-like through-hole in a 0.5 to 1 mm thick Si substrate. A heater array (not shown) as ejection means arranged in a zigzag pattern on each side across the ink flow path (not shown), and a recording element substrate in a direction orthogonal to the heater array (not shown) On both sides of H1100 and H1101, connection pads H1102 connected to the heater array (not shown) and arranged on both outer sides of the recording element substrates H1100 and H1101 are provided.
[0018]
For example, a TAB tape is employed as the electrical wiring tape (hereinafter also referred to as a wiring tape) H1300.
[0019]
The TAB tape is a laminate of a base film, copper foil wiring, and a cover film that protects the wiring.
[0020]
The copper foil wiring has a trace of a predetermined shape (not shown) that connects the two recording element substrates H1100, H1101 and the electrical contact substrate H2200.
[0021]
Inner leads H1302 whose surfaces are Au-plated as connection terminals extend to two sides of the device holes H13050 and H13051 corresponding to the connection pads of the recording element substrates H1100 and H1101.
[0022]
The electric wiring tape (TAB tape) H1300 has the cover film side bonded and fixed to the surface of the second plate H1400 via a thermosetting epoxy resin adhesive layer. The base film of the electric wiring tape (TAB tape) H1300 is: A smooth capping surface of the recording element unit H1002 is brought into contact with a capping member (not shown) when used in the ink jet recording apparatus.
[0023]
The electrical wiring tape H1300 is electrically connected to the two recording element substrates 1100 and H1101 by connecting the inner leads H1302 of the electrical wiring tape H1300 and the connection pads H1102 provided with stud bumps on the recording element substrates H1100 and H1101 in a single manner. This is done by joining the point ILB (inner lead bonding) ((3) electrical bonding of the electrical wiring tape H1300 and the recording element substrates H1100 and H1101).
[0024]
After the ILB bonding, the electrical connection portion is sealed with a first sealant H1307 and a second sealant H1308 in order to protect it from ink corrosion and external impact (4) of the electrical wiring tape H1300. (Sealing of electrical joints between the stacked layers and the recording element substrates H1100 and H1101).
[0025]
The first sealing agent H1307 mainly seals the outer peripheral portions of the mounted recording element substrates H1100 and H1101, and the second sealing agent is an electrical connection between the recording element substrates H1100 and H1101 and the electrode wiring tape H1300. The front side of the connection part is sealed.
[0026]
The electrode wiring tape H1300 is bonded to the second plate by applying or transferring a thermosetting epoxy adhesive in the range of the bonding length of the H1400 in advance, the electrode wiring tape H1300 being pressed and heated.
[0027]
Then, the recording element unit H1002 is assembled by bonding the electrical wiring tape H1300 and the electrical contact substrate H2200. (5) Bonding of electrical wiring tape H1300 and electrical contact substrate H2200.
[0028]
[Problems to be solved by the invention]
However, in the above-described technique, when the electrode wiring tape H1300 and the second plate H1400 are pressure-bonded, a part of the adhesive may be pushed out from the adhesion interface to the periphery of the device holes H13050 and H13051. was there.
[0029]
Adhesive that is excessively pushed near the inner lead H1302 flows from the root of the inner lead H1302 toward the tip, and wets the surface of the inner lead H1302.
[0030]
The adhesive thinly solidified on the surface of the inner lead H1302 limits the bending of the inner lead H1302, and reduces the bonding strength between the inner lead H1302 and the connection pad H1102 during ILB.
[0031]
Alternatively, a defect occurs in which the connection pad H1102 is peeled off from the recording element substrates H1100 and H1101 after ILB.
[0032]
The present invention has been made in view of the above-described problems, and the object of the present invention is to prevent an excessive amount of adhesive from being pushed out to the root of the inner lead and to achieve a good ILB. and a recording element unit of the ink jet head.
[0033]
[Means for Solving the Problems]
The present invention has achieved the above object by the following technical configuration.
[0034]
(1) and the recording element substrate having a plurality of connection pads, and a plate to which the recording element substrate is fixed, a device hole for placing the recording element substrate, the plurality exposed on at least one side of said device hole A lead group consisting of a plurality of leads that are electrically connected to the connection pads; and a trace group consisting of a plurality of traces for conduction, each drawn from the plurality of leads in a direction away from the device hole. A recording element unit of an ink jet head having a wiring tape, wherein a surface of the electric wiring tape on which irregularities are formed according to the plurality of traces is adhered to the plate with an adhesive, and the lead By making Wi> W the width W of the group and the width W of the trace group at the location where the adhesive is provided, the adhesive Recording element unit from provided the point ink jet head is characterized in Rukoto suppress extrusion of the adhesive toward the lead group.
[0035]
(2) The recording element unit of the ink jet head according to (1), wherein the electrical wiring tape includes a flexible film that covers the trace group on a surface bonded to the plate.
[0038]
That is, conventionally, even when the adhesive at the bonding interface has been pushed out along the trace of the wiring, according to the invention according to the present application, the bonding pushed out toward the contact portion provided with the inner lead. As the agent moves toward the contact portion, the momentum is reduced as the shape of the trace expands, so that excessive adhesive can be prevented from being pushed out to the root of each inner lead.
[0039]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0040]
(First embodiment)
1-3 is a figure of the Example of the invention concerning this application.
[0041]
FIG. 1 is a diagram of a first embodiment according to the present invention, FIG. 2 is a diagram of a TAB tape in the first embodiment, and FIG. 3 is a schematic sectional view of the TAB tape in the first embodiment.
[0042]
In addition, since the structure of a present Example is the same as what was demonstrated in the prior art example except the trace of an electrical wiring tape, the same code | symbol is attached | subjected to the same structure and detailed description is abbreviate | omitted.
[0043]
H1304a, H1304b, H1304c, and H1304d are groups of traces, H1306 is a connection portion including inner leads H1302, A and B are epoxy adhesive layers, BF is a base film, CF is a cover film that is a flexible film, and E is The direction of the electrical contact substrate H2200, W is the width of the group of traces, Wi is the pitch width of the inner leads H1302 which is the width of the connection portion H1306, and Ta is the trace of the electrical wiring tape H1300 in this embodiment.
[0044]
As shown in FIG. 3, the electric wiring tape H1300 is composed of a base film BF made of 50 μm polyimide, conductive traces Ta connected to individual inner leads H1302 formed by 35 μm copper foil wiring, and 4 μm for protecting the traces Ta. Cover film CF made of polyparaferylene terephthalamide (PPTA), base film BF and copper foil wiring, and epoxy adhesive layers A and B for bonding the copper foil wiring and cover film CF, respectively.
[0045]
The trace Ta is designed so that the inner leads H1302 of the device holes H13050 and H13051 and the electrical contact substrate H2200 are connected to each other, and the width and routing of each trace Ta are designed so as to maintain a predetermined resistance relationship in the electrical wiring tape H1300. .
[0046]
The two connecting portions H1306 of the recording element substrate H1101 are each provided with 24 inner leads each having a width of 80 μm and arranged at a pitch of 0.24 mm (see FIG. 2).
[0047]
Similarly, eleven inner leads H1302 each having a width of 80 μm are provided at two connection portions H1306 of the recording element substrate H1100, and are arranged at a pitch of 0.17 mm (see FIG. 2).
[0048]
The copper foil wiring forming the trace Ta is bonded onto the smooth base film BF, and the unevenness of the trace Ta is covered with the cover film CF.
[0049]
For this reason, the surface of the cover film CF, that is, the surface bonded to the recording element substrates H1100 and H1101 of the electric wiring tape H1300 has a minute surface step due to the trace Ta having a thickness of 35 μm (see FIG. 3). ).
[0050]
On the other hand, as shown in FIG. 2, the traces Ta drawn from the two sides of each of the two device holes H13050 and H13051 form at least four trace groups H1304a, H1304b, H1304c, and H1304d.
[0051]
The groups H1304b and H1304d of the trace Ta that communicate with the inner lead H1302 of the connection portion H1306 on the side (E direction) of the electrical contact substrate H2200 (not shown) are drawn in a direction away from the connection portion H1306.
[0052]
Trace groups H1304a and H1304c are drawn out from the connection portion H1306 on the side opposite to the electrical contact substrate H2200, respectively.
[0053]
The group of traces H1304a is divided into two small groups and drawn out with the group of traces H1304b in between.
[0054]
The average width of the individual traces Ta in the group of traces 1304b is smaller than the average width of the individual traces Ta in the group of traces H1304a having a long extraction distance. As a result, the group of traces H1304b is an area in which the thin traces Ta are integrated. Form.
[0055]
In the multi-recording element type recording element unit H1002 of this embodiment, the relative positional accuracy of each recording element is important in order to prevent image color misregistration.
[0056]
In order to ensure this relative accuracy, the electric wiring tape H1300 is bonded after the two recording element substrates H1100 and H1101 are mounted.
[0057]
The electrical wiring tape H1300 and the plate assembly H1202 are bonded in the order of the transfer of the adhesive X to the adhesive surface of the plate assembly H1202, the alignment of the electrical wiring tape H1300, and the pressure-bonding and heating cure of the adhesive X.
[0058]
As a feature of the electrical wiring tape H1300 of the present embodiment, the group of traces H1304b drawn from the connection part H1306 facing a wide adhesive area is in the vicinity of the connection part H1306 and away from the connection part H1306. The layout is made so that the width W becomes smaller.
[0059]
As schematically shown in FIG. 1, the pitch width Wi of the inner leads H1302 is about 6.48 mm, and the width W of the group of traces is about 5.04 mm at a point about 3.5 mm away from the side of the device hole H13050. is there.
[0060]
According to the study by the present inventors, a phenomenon that the adhesive X is extruded along the pattern of the trace Ta of the electric wiring tape H1300 was observed.
[0061]
In the electrical wiring tape H1300 of this embodiment, the adhesive X is easily pushed out along the pattern of the trace group H1304b to the connection portion H1306 adjacent to the relatively wide adhesion area, but in the vicinity of the connection portion H1306, the trace group H1304b. Therefore, the force of the adhesive X to be pushed out or the amount of the adhesive X to be pushed out itself is reduced, and an undesirable flow of the adhesive X to the root of the inner lead H1302 is prevented.
[0062]
(Comparative examples and other examples)
Next, a comparative example will be described with reference to FIGS.
[0063]
FIG. 4 is a diagram of a comparative example of this embodiment.
[0064]
FIG. 5 is a diagram showing the difference in the flow of adhesive after TAB bonding with the comparative example of this example, FIG. 5 (a) is a diagram of the comparative example, and FIG. 5 (b) is a diagram of this example. It is.
[0065]
Tb is a trace of the electric wiring tape H1300 in this embodiment, and X is an adhesive.
[0066]
In this comparative example, the width W of the group of traces drawn from the connection portion H1306 is laid out at about 8.24 mm, which is larger than the pitch width Wi of the inner leads H1302.
[0067]
5 (a) and 5 (b), the electric wiring tape H1300 has a layer structure as shown in FIG. 3, and the adhesive X is about 20 μm per unit area on the bonding surface of the plate assembly H1202. The transfer amount was controlled so as to obtain a thickness.
[0068]
The adhesive X was a thermosetting epoxy adhesive, and was subjected to heat curing at about 130 to 150 ° C. for 30 seconds after the electrical wiring tape H1300 and the recording element substrates H1100 and H1101 were pressure-bonded.
[0069]
As a result, in the configuration of the comparative example, the adhesive X was pushed out near the root of the inner lead H1302 of the connecting portion H1306 (FIG. 5A), and the ILB was hindered.
[0070]
On the other hand, in the configuration of this example, the adhesive X was not seen at the base of the inner lead H1302 (FIG. 5B), and the inner lead H1302 maintained the original bending rigidity, and good ILB was possible. .
[0071]
The cause of this phenomenon is as follows: (1) A path is formed between a minute step (unevenness) on the surface of the cover film CF corresponding to the trace Ta of the copper foil wiring and the recording element substrates H1100 and H1101. It can be considered that the configuration of the electric wiring tape H1300 reduces the extrusion of the adhesive X as the path width increases.
[0072]
At the same time, in the case of the present embodiment, (2) the portion of the group of traces H1304b where the traces Ta having a small average width are concentrated becomes a portion where the bending rigidity of the electric wiring tape H1300 is weak, and the trace is caused by the thermal linear expansion during bonding. In the group H1304b, it is considered that a slight lift occurred between the electric wiring tape H1300 and the plate assembly H1202, and the action of expanding the path was synergized.
[0073]
In this embodiment, the pattern as shown in FIG. 1 is used for the group of traces H1304b drawn from the connection portion 1306 adjacent to the relatively wide bonding area. However, the configuration of the group of traces H1304b is changed to other groups of traces, For example, it may be used simultaneously for the trace group H1304d.
[0074]
As another embodiment, as shown in FIG. 6, only in the vicinity of the connecting portion H1306, the width of the trace group H1304b is once reduced to recover the loss due to the wiring resistance, and the width of the trace group H1304b is restored. It is also possible to expand
[0075]
As described above, the advantages obtained from this embodiment are particularly advantageous for the manufacturing method in which ILB is performed after TAB bonding.
[0076]
On the other hand, even when the TAB-recording element substrate H1100, H1101 assembly is mounted on the plate assembly H1202 after the ILB, stress is exerted on the bonded inner lead H1302 in the process in which the extruded adhesive X is cured and deformed. Defects such as peeling of stud bumps may occur.
[0077]
If this is significant, there is a concern of destroying the entire inner lead H1302 group that has been subjected to ILB sealing.
[0078]
For this reason, the advantage obtained from the present embodiment is effective even when the TAB-recording element substrate H1100 and H1101 assembly is mounted on the plate assembly H1202 after ILB.
[0079]
In addition, this invention is not limited to structures, such as a specific material in an Example, a shape.
[0080]
For example, the invention according to the present application can be adopted for a single-chip type recording element unit and its manufacturing process, and the effects described can be obtained.
[0081]
Moreover, you may use a flexible substrate, a jumping lead type flexible substrate, etc. as an electrical wiring tape.
[0082]
【The invention's effect】
As described above, according to the present invention, it is possible to prevent the adhesive of excess to the base of the inner lead is extruded, it is possible to provide a recording element unit of the ink jet head capable good ILB.
[0083]
That is, by adopting the present invention for tracing and TAB bonding of an electric wiring tape such as TAB tape, the adhesive does not flow into the connecting portion, and there is no problem due to the adhesive protruding into the ILB after TAB bonding.
[Brief description of the drawings]
FIG. 1 is a diagram of a first embodiment according to the present invention. FIG. 2 is a diagram of a TAB tape in the first embodiment. FIG. 3 is a schematic sectional view of a TAB tape in the first embodiment. FIG. 5 is a diagram showing a difference in the flow of adhesive after TAB bonding with the comparative example of the present embodiment, and FIG. 5 (a) is a diagram of the comparative example, and FIG. 5 (b). FIG. 6 is a diagram of another embodiment of the present invention. FIG. 7 is an exploded perspective view illustrating the ink jet head. FIG. 8 is a diagram illustrating the ink jet head. FIG. 9 is a diagram illustrating the ink jet head. Enlarged view around the recording element substrate [Explanation of symbols]
H1002 Recording element unit H1003 Ink supply unit H1100 First recording element substrate H1101 Second recording element substrate H1102 Connection pad H1200 First plate H1202 Plate assembly (element substrate)
H1300 Electrical wiring tape H1302 Inner leads H1304a, H1304b, H1304c, H1304d Trace group H1306 Connection part H1400 Second plate H2000 Tank holder H13050, H13051 Device hole Ta Trace W Trace group width Wi Inner lead pitch width

Claims (2)

A recording element substrate having a plurality of connection pads;
A plate to which the recording element substrate is fixed,
The recording element device hole for placing a substrate, a lead group including a plurality of leads at least said exposed on one side a plurality of connection pads and electrically connecting the said device hole, wherein the plurality in a direction away from the device hole A trace group consisting of a plurality of traces for conduction, each drawn from each of the leads, and an electrical wiring tape comprising:
A recording element unit of an inkjet head having:
The surface of the electrical wiring tape on which irregularities are formed according to the plurality of traces is adhered to the plate with an adhesive,
The width Wi of the lead group and the width W of the trace group at the place where the adhesive is provided satisfy Wi> W, so that the direction from the place where the adhesive is provided toward the lead group is set. recording element unit of the ink jet head, characterized in Rukoto suppress extrusion of the adhesive. The recording element unit of an ink jet head according to claim 1, wherein the electrical wiring tape includes a flexible film that covers the trace group on a surface bonded to the plate.

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