JPH07294954A - Tab compression-bonding device for liquid crystal cell - Google Patents

Abstract

PURPOSE:To make a uniform pressurizing force act between a liquid crystal cell and TAB to subject them to thermo compression bonding regardless of thermal deformation of a pressure head. CONSTITUTION:With respect to a reception base 23, a frame member 27 whose upper side is opened is stuck to a base plate 26 which has both ends fixed on an attaching plate 24, and a rubber sheet 28 as an elastic member having a prescribed thickness is stuck in this frame member 27, and a baseplate 29 is stuck on this rubber sheet 28, and a reception member 30 is set on this baseplate 29. These baseplate 29 and reception member 30 are made of a soft steel material like quenched steel or the like of SUS together; and if the pressurizing force from a pressure head 21 is not uniform throughout because of thermal deformation of a contact part 21b of the pressure head 21, the reception member 30 is deformed in accordance with the distribution of the pressurizing force to follow the contact part 21b of the pressure head 21.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a TAB pressure bonding device for a liquid crystal cell, which is used for fixing a TAB bonded to a liquid crystal cell via an ACF by thermocompression bonding.

[0002]

2. Description of the Related Art A liquid crystal panel in a liquid crystal display device is a TCP (Tape Carrier Pac) in which a driver IC is mounted in a liquid crystal cell in which a liquid crystal material is sealed between a pair of glass plates.
TAB (Tape Automated Bonding) consisting of a kage) is mounted, and the mounting of this TAB is as shown in FIG.
It is performed by using ACF (Anisotropic Conductive Film).

First, as shown in FIG. 1, on an ITO (tin oxide / indium oxide) electrode formed on the peripheral edge of one of the two glass plates 1a and 1b constituting the liquid crystal cell 1. The ACF 2 is attached to the liquid crystal cell 1, and the liquid crystal cell 1 is positioned in the XY direction and the rotation direction (θ direction) at the positioning station S ₁ . Liquid crystal cell 1
When the positioning is performed, the liquid crystal cell 1 is taken out from the positioning station S ₁ by a vacuum suction means or the like and set on the XY stage 3 arranged in the TAB temporary pressure bonding station S ₂ .

In the TAB temporary pressure bonding station S ₂ , the TAB 5 is cut from the TCP tape 4 and sent to the TAB positioning section 6 by the vacuum suction means. Then, the TA positioned by the TAB positioning unit 6
B5 is taken out by the vacuum suction means, and the TAB5 is sequentially positioned at predetermined positions of the liquid crystal cell 1 in a state where the image recognition means strictly aligns the alignment marks provided on the liquid crystal cell 1 and the TAB5 respectively. And is temporarily pressure-bonded by using the adhesive force of ACF2.

After the required number of TABs 5 are temporarily pressure-bonded to the liquid crystal cell 1, the liquid crystal cell 1 is evacuated by a vacuum suction means.
It is sent to the TAB main pressure bonding station S ₃ . And, in this TAB main pressure bonding station S ₃ ,
The receiving member is brought into contact with the lower side of the portion where the AB 5 is temporarily pressure-bonded, and the ACF 2 is thermally cured by thermocompression bonding with the heated pressure head 6.

Thus, as shown in FIG. 2, the liquid crystal cell 1
On the ITO electrode 7 on the glass plate 1b.
CF2 is adhered, but this ACF2 is made by dispersing bonding particles 2b in an epoxy thermosetting resin 2a, and an output lead 5a is formed on a TAB 5 mounted in this liquid crystal cell 1. The ACF 2 is for electrically connecting the output lead 5a to the ITO electrode 7. With the TAB 5 bonded to the liquid crystal cell 1,
In the AB main press-bonding station S ₃ , when both are pressed under heating, the thermosetting resin 2a first fluidizes, and as shown in FIG.
The side ITO electrode 7 and the ACF 2 are electrically connected to each other through the bonding particles 2b, and the temperature is further raised to thermoset the thermosetting resin 2a. Although it depends on the material of the ACF and the like, generally, in the main pressure bonding step, the pressure head 6 is used.
Thus, the ACF ² is applied with a pressure of about 20 kg / cm ^{2 to} 50 kg / cm ² at a temperature of about 150 ° C. to 180 ° C.

Here, in the main pressure bonding, not all the TABs 5 attached to the liquid crystal cell 1 are individually thermocompression bonded, but all the TABs 5 provided on each side are thermally bonded at the same time. Therefore, the pressure head 6 and its receiving member must be longer than the entire length of the liquid crystal cell 1. In recent years, the liquid crystal display tends to have a large screen, and the size of the liquid crystal cell 1 is considerably long, such as several cm to ten and several cm. Moreover, the width of the portion to be crimped by the pressure head 6 is very narrow,
Therefore, the contact portion of the pressure head 6 has an extremely elongated shape. Although thermocompression bonding is performed using the pressure head having such a structure, the liquid crystal cell 1 and the TAB 5 are required unless uniform pressure is exerted over the entire length of the pressure head.
Between the and, a partial electrical connection failure will occur.

From the above requirements, the pressure head and the receiving member, which are members for holding and pressing the liquid crystal cell and the TAB,
Both must strictly maintain parallelism. For this,
As for the pressure head and the receiving member, it is natural that strict finishing processing is performed, and the materials thereof are also members that are not easily deformed by external force or heat. Since the pressure head is heated, it must be a member having good thermal conductivity in addition to this requirement, and therefore it is made of a hard metal material. On the other hand, ceramics are generally used as the material of the receiving member side from the viewpoint of preventing deformation.

[0009]

By the way, at the time of thermocompression bonding by the pressure head, since the ACF is heated to about 150 ° C. to 180 ° C., it is necessary to heat the pressure head itself to about 300 ° C. Moreover, the width of the pressing portion of the TAB by the pressing head is quite narrow, and since the entire length of the liquid crystal cell is pressed at one time, the total length is extremely long. Thermal deformation occurs over a long period of time. This thermal deformation causes warping or bending depending on the material, shape, etc. Even if there is a slight deformation, a uniform pressure bonding force is applied over the entire length between the liquid crystal cell and the TAB at the time of thermocompression bonding. However, problems such as poor electrical connection between the ITO electrode 7 and the bonding particles 2b of the ACF2, which occur through the bonding particles 2b of the ACF2, occur.

The present invention has been made in view of the above points, and an object thereof is to apply a uniform pressing force between the liquid crystal cell and the TAB even when the pressure head is thermally deformed. The purpose is to enable thermocompression bonding.

[0011]

In order to achieve the above-mentioned object, according to the present invention, a TAB is attached to a liquid crystal cell via an ACF and set on a receiving member and heated from above. The TAB is thermocompression-bonded to the liquid crystal cell by lowering the head, and the receiving member is formed of a soft steel material, and the receiving member is mounted on the elastic member so that the pressing head is activated. The TAB is pressure-bonded to the liquid crystal cell so that the receiving member follows the pressure head.

[0012]

The TAB is bonded to the liquid crystal cell and set on the pedestal, and the pressure head heated from above is lowered to perform thermocompression bonding. As a result, the liquid crystal cell in which the ACF is interposed and the TAB are sandwiched between the receiving member and the pressure head, and a predetermined pressing force acts between them to perform thermocompression bonding. When the pressure head is thermally deformed, the receiving member mounted on the elastic member and made of a soft steel material is deformed by the pressing force so as to follow the deformation of the pressure head. . Therefore,
A substantially uniform pressing force acts on the liquid crystal cell and the TAB as a whole, so that the electrodes on the liquid crystal cell side and the output leads of the TAB are mounted in a surely electrically connected state.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. Thus, as described above, the ACF ₂ of the glass plate 1b of the liquid crystal cell 1 is processed at the TAB temporary pressure bonding station S _2.
The TAB 5 is attached on top (herein, in the following description, the state in which the TAB 5 is attached to the liquid crystal cell 1 is referred to as a work W), but this work W is transferred to the TAB main pressure bonding station S ₃ . Then, it is positioned at a predetermined position and thermocompression-bonded by applying a pressure from above and below under heating. Therefore, in the TAB main pressure bonding station S ₃ , the work W is placed on the work mounting table 10
The above is fixedly supported by vacuum suction.

In order to perform the thermocompression bonding of the work W, the apparatus shown in FIGS. 4 to 6 is used. In the figure, 11 is a frame of the main body of the apparatus, and this frame 11 includes a pair of left and right side plates 11a, 11a and these side plates 11a, 11a.
and a top plate 11b provided on the upper part of a. Top 11
A slide guide 12 is vertically provided on the slide b, and guide rails 12a, 12 are provided on both front and back surfaces of the slide guide 12.
b is provided. A pressure unit 13 is mounted on the front guide rail 12a so as to be able to move up and down, and a tape running unit 14 is mounted so that it can be moved up and down on the back guide rail 12b. The pressure unit 13 and the tape running unit 14 are lift blocks 1 that move up and down along the guide rails 12a and 12b, respectively.
5 and 16 are provided.

The elevating block 15 on the side of the pressurizing unit 13 is connected to an air cylinder 17 as an elevating drive means provided on the top plate 11b of the frame 11, and is vertically moved by this air cylinder 17. . Further, the elevating block 16 of the tape running unit 14 is moved up and down in conjunction with the elevating block 15, and for this purpose, a connecting rod 18 is fixedly provided on the elevating block 15 and this connecting rod is provided. Reference numeral 18 penetrates through the slide guide 12 in the thickness direction, is inserted into a guide hole 19 which is elongated in the vertical direction, and is further inserted into an insertion hole 20 formed in the elevating block 16. This insertion hole 20
It is a long hole extending in the vertical direction. Therefore, when the elevating block 15 descends, the elevating block 16 also descends in conjunction with this, but even if the elevating block 16 stops midway, the elevating block 15 is further moved. Is configured to be able to descend independently.

Lifting block 1 in pressurizing unit 13
A pressure head 21 is attached to the lower end portion of 5.
As shown in FIG. 7, the pressurizing head 21 has a narrow contact portion 21b extending from the lower end of a main body portion 21a in which a rod heater 22 is mounted, and contacts the workpiece W. Is the contact portion 21b.

The pressure head 21 is held in a heated state by the heater 22 and is lowered by the elevating block 15 by the air cylinder 17, so that the contact portion 21b comes into contact with the portion of the work W to be crimped, Although pressed from above, in order to receive this work W from below,
A cradle 23 is provided. As shown in FIG. 7, the pedestal 23 includes side plates 11a, 11a of the frame 11.
A base plate 26, both ends of which are fixed by bolts 25, 25 is provided on a mounting plate 24 that is installed between them, and a frame member 27 having an open upper side is fixedly provided on the base plate 26. A rubber sheet 28 as an elastic member having a predetermined thickness is attached inside the frame member 27, and a base plate 29 is attached on the rubber sheet 28. The receiving member 30 is mounted on the receiving member 30, and the rod heater 31 is also built in the receiving member 30. The base plate 29 and the receiving member 30 are made of a relatively soft steel material such as SUS hardened steel.

The upper surface of the receiving member 30 on the receiving table 23 is a flat receiving surface 30a, and the work W is brought into contact with the receiving surface 30a. Then, when the work W set in this way is pressed against the pressing head 21 from above and a predetermined load is applied, this pressing force is applied to the rubber sheet via the receiving member 30 and the base plate 29. The rubber sheet 28 is elastically deformed by acting on 28, but the side surface of the base plate 29 is guided by the side portion 27a of the frame member 27, whereby the rubber sheet 28 is elastically deformed. As a result, the receiving member 30 is displaced only in the direction in which it rises and falls within the frame member 27. Further, in order to restrict the movement of the receiving member 30 in the direction projecting from the frame member 27, the frame member 27 is formed with tip bending portions 27b and 27b, and the receiving member 30 has the tip bending portions 27b and 27b. It is designed so as to project upward from a portion between them.

Further, the base plate 26 of the pedestal 23
Is fixed to the mounting plate 24 only at both ends thereof, and the intermediate portion is in a non-fixed state. Then, three adjusting bolts 32 are screwed under the mounting plate 24 at both end portions and a central portion thereof, and each of the bolts 32 is in contact with the lower surface of the base plate 26. Therefore, by screwing these adjusting bolts 32, the base plate 26 can be bent or curved in the longitudinal direction thereof, whereby the receiving surface 30a of the pedestal 23 can be bent.
The flatness can be adjusted.

The tape running unit 14 as another member which is guided by the slide guide 12 and moves up and down,
Side plates 34, 34 are provided at both ends of a connecting plate 33 fixedly provided on the elevating block 16, and a supply reel 35 is provided between the side plates 34, 34 in front of the position of the pressure unit 13. A take-up reel 36 is provided on the back surface side of the slide guide 12, and when the pressure head 21 comes into contact with the work W from the supply reel 35, the thermosetting resin 2a having an adhesive property that constitutes the ACF 2 is provided.
In addition, a protection tape 37 having a width wider than the entire length of the pressurizing head 21 in order to protect it from direct adhesion of dust or the like.
Are being supplied. The protective tape 37 is guided to the lower position of the pressure head 21 by the guide rollers 38 and 39 provided between the side plates 34 and 34, and is further guided to the take-up reel 36 via the guide roller 40. It is like this. Although not shown, the take-up reel 36 is equipped with a take-up means such as a motor so that the protective tape 37 can be run.

A work holding member 41 is provided at a front portion between the side plates 34, 34. In this work holding member 41, a large number of elastic rings 41b are attached to a rod member 41a with a predetermined pitch interval,
When the work head W is thermocompressed, the elastic ring 4 of the work holding member 41 is first moved when the pressing head 21 is lowered.
1b contacts the upper surface of the liquid crystal cell 1 on the work W,
By applying the entire load of the tape feeding unit 14 on the liquid crystal cell 1, when the work W is warped or curved, it can be corrected.

The present embodiment is configured as described above, and its operation will be described below with reference to FIGS. 8 to 10. First, with the air cylinder 17 in a contracted state, as shown in FIG. 8, the pressing unit 13 and the tape running unit 14 are held in an elevated state, and the work W is set on the work mounting table 10. , Its positioning. Here, when the work W is accurately positioned,
In the lower part of the portion of the work W where the TAB 5 is thermocompression-bonded to the liquid crystal cell 1, the receiving member 3 forming the receiving table 23 is formed.
The receiving surface 30a of 0 comes into contact. Here, since the rod heater 31 is built in the receiving member 30,
The work W is preheated by operating the rod heater 31. The preheating for this work W is
The thermosetting resin 2a of the ACF 2 is in a relatively low state where it does not soften, for example, about 60 ° C. When preheating is not required, the rod heater 31 is provided on the receiving member 30 side.
Need not be provided. Along with this, the rod heater 22 attached to the pressure head 21 is also operated to heat the pressure head 21, but the temperature of the pressure head 21 is considerably higher than that of the receiving member 30 as described later. It will be expensive.

Therefore, the elevating block 15 is lowered by operating the air cylinder 17 in the extending direction. A connecting rod 18 is provided on the elevating block 15, and the connecting rod 18 is also connected to the elevating block 16. Therefore, when the air cylinder 17 operates, the pressurizing unit 13 and the tape running unit 14 move. It goes down in tandem. Then, as shown in FIG. 9, in the middle of this descending stroke, first, the elastic ring 4 in the work holding member 41 provided in the tape traveling unit 14 is provided.
1b contacts the liquid crystal cell 1 of the work W, and the tape running unit 14 stops at this position. In this state, the load of the entire tape traveling unit 14 acts on the liquid crystal cell 1, so that the deformation of the work W in the direction along the thermocompression bonding line is corrected, and at least in this direction, the work W is corrected. The whole becomes substantially flat.

When the extension of the air cylinder 17 is further continued from the state shown in FIG. 9, the elevating block 15 descends independently, and as shown in FIG. The pressure head 21 contacts the upper surface of the work W. Here, since the protective tape 37 runs under the pressure head 21 between the guide rollers 38 and 39, the pressure head 21 is protected by the protective tape 37.
The pressure head 21.
Is pressed against the work W via the protective tape 37. As a result, the contact portion 21b of the pressure head 21 can be prevented from being contaminated by being in direct contact with the ACF 2 or the like.

By the pressing force of the air cylinder 17, the work W is held between the contact portion 21b of the pressure head 21 and the receiving surface 30a of the receiving member 30 of the pedestal 23 on the fixed side, and is applied. The heat of the pressure head 21 reaches the ACF 2 interposed between the liquid crystal cell 1 of the work W and the TAB 5, and the thermosetting resin 2a of this ACF 2 is fluidized. Then, due to the holding force from above and below, the bonding particles 2b and the ITO electrode 7 of the liquid crystal cell 1 and the TAB are formed.
5 is connected to the output lead 5a of
The TO electrode 7 and the output lead 5a are electrically connected. When the temperature of the ACF 2 further rises, the thermosetting resin 2a starts to cure. Therefore, by applying a pressing force to the pressure head 21 for a predetermined time, the TAB5
Will be fixed to the liquid crystal cell 1 by thermocompression bonding. When the thermocompression bonding is completed, the air cylinder 17 is contracted so that the pressure unit 13 first rises to a predetermined height position, and then the tape running unit 14 as well as the pressure unit 13 ascends. , The state of FIG. 7 is restored. Then, the protective tape 37 is wound by a predetermined amount by the take-up reel 36, and the preparation for thermocompression bonding of the next work W is completed.

A rod heater 22 is attached to the pressure head 21 of the pressure unit 13 to heat the pressure head 21. Here, the heating of the pressure head 21 is for fluidizing the thermosetting resin 2a in the ACF 2 during thermocompression bonding, and further for heating it to the curing temperature thereof. Generally, the heating temperature is at least 150 ° C. It is said that the temperature needs to be about 180 ° C. The heat from the pressure head 21 contacts the contact portion 21.
b is transmitted through the protective tape 37 and the TAB 5 in the work W, and in order to cause a rapid curing reaction, it is necessary to rapidly raise the heating temperature. Will be heated to temperatures of 300 ° C. and above. Contact part 21
Since b has a narrow width and has to reach the entire length of the liquid crystal cell 1, the length is extremely long. Therefore, the contact portion 21b of the pressure head 21 may be deformed by the influence of heat. Of course, this thermal deformation is extremely slight, but even if it is slightly deformed, a uniform pressing force cannot be exerted on the work W, and as a result,
The ITO electrode 7 and the output lead 5a of the TAB 5 cause a contact failure.

In the present invention, it is assumed that the pressure head 21 is subject to thermal deformation, and the pressure head 2 is used.
When the contact portion 21b of No. 1 is thermally deformed, the pedestal 23 side follows the deformation so that the thermal deformation is absorbed by the pedestal 23 side. That is, the contact portion 2 of the pressure head 21
In the frame member 27, the receiving member 30 of the pedestal 23, which is a counterpart member on which the workpiece W is held together with the 1b, is
It is supported by a rubber sheet 28 and is fixed by a frame member 27 in a direction other than the pressing direction acting from the pressing head 21, but can be displaced in the pressing direction by the amount of elastic deformation of the rubber sheet 28. Has become. Moreover, since the receiving member 30 is not formed of a hard member such as ceramics but is formed of a relatively soft steel material, the pressure applied from the pressure head 21 is not uniform throughout. In this case, the receiving member 30 is deformed so as to follow the contact portion 21b of the pressure head 21 according to the distribution of the pressing force. As a result, a substantially uniform pressing force is applied to the work W along the thermocompression bonding line, and all the ITO electrodes 7 are securely connected to each output lead 5a of the plurality of TABs 5 that are pasted over the entire length thereof. Will be done.

Here, even if the receiving surface 30a of the receiving member 30 is deformed so as to follow the pressing force of the pressure head 21, the amount of deformation is very small. Therefore, the receiving member 30 is only slightly deformed. However, when the pressure head 21 is operated for a long period of time, it is deformed to such an extent that it cannot be corrected only by copying the receiving member 30 of the receiving member 30 due to the pressing force of the pressure head 21 due to the accumulated influence of heat. become. In this case, an appropriate one of the three adjusting bolts 32 screwed into the mounting plate 24 is screwed, and the tip of the screw adjusts the base plate 26 of the pedestal 23 to forcibly bend it. In this way, adjustment is performed so as to follow the deformation of the pressure head 21.

As described above, when the pressurizing head 21 is thermally deformed, the pedestal 23 side is made to follow this, and a rough copy of this copy is the adjusting bolt 32.
By forcing the receiving member 30 to be bent by screwing, the receiving member 30 can be elastically bent when pressed by the pressure head 21. Since it is possible to make a detailed copy, it becomes possible to make a more accurate copy. Further, the frequency of performing the copy correction of the pedestal 23 using the adjustment bolt 32 can be reduced, and this correction does not need to be performed very strictly, so that the forced copy can be easily performed. Further, by providing such a copying mechanism, even if the pressurizing head 21 is considerably thermally deformed, it is not necessary to replace it, so the pressurizing head 2
1 has a longer life and can be replaced less frequently.

[0030]

As described above, according to the present invention, the receiving member is made of a soft steel material and the receiving member is mounted on the elastic member. Since the TAB is pressure-bonded to the liquid crystal cell so as to follow the pressure head, even if the pressure head is thermally deformed, a uniform pressing force is applied between the liquid crystal cell and the TAB to provide them. There is an effect that the electrodes can be thermocompression-bonded with the electrodes reliably connected electrically.

[Brief description of drawings]

FIG. 1 is a process explanatory view showing a process of mounting a TAB on a liquid crystal cell forming a liquid crystal panel.

FIG. 2 is an enlarged cross-sectional view showing a state in which a liquid crystal cell and a TAB are bonded together.

FIG. 3 is an enlarged cross-sectional view showing a state in which a liquid crystal cell and TAB are thermocompression bonded.

FIG. 4 is a front view of the configuration of a TAB pressure bonding device for a liquid crystal cell showing an embodiment of the present invention.

5 is a diagram viewed from the XX direction in FIG.

FIG. 6 is a perspective view showing an operating member in a TAB pressure bonding device for a liquid crystal cell.

FIG. 7 is a cross-sectional view of a pressure head and a receiving member.

FIG. 8 is an operation explanatory view showing a state of each operating member before the thermocompression bonding operation.

FIG. 9 is an operation explanatory view showing a state of each operating member before the thermocompression bonding.

FIG. 10 is an operation explanatory view showing a state of each operating member during thermocompression bonding.

[Explanation of symbols]

 1 Liquid Crystal Cell 2 ACF 5 TAB 10 Work Placement Table 12 Slide Guide 13 Pressure Unit 14 Tape Travel Unit 15, 16 Elevating Block 17 Air Cylinder 21 Pressure Head 21b Contact Part 22 Rod Heater 23 Cradle 24 Mounting Plate 26 Base Plate 27 Frame Member 28 Rubber sheet 29 Base plate 30 Receiving member 30a Receiving surface 32 Adjustment bolt 34 Side plate 41 Work holding member 41a Rod member 41b Elastic ring W Work

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroshi Umezu 2-6-2 Otemachi, Chiyoda-ku, Tokyo Inside Ritsudenshi Engineering Co., Ltd. (72) Hiroyuki Sasaki 2--6, Otemachi, Chiyoda-ku, Tokyo No. 2 inside Nitrate Electronics Engineering Co., Ltd.

Claims (4)

[Claims] 1. A liquid crystal cell, in which TAB is attached via ACF, set on a receiving member, and a PRESS head heated from above is lowered to thermocompress TAB to the liquid crystal cell. By forming the receiving member from a soft steel material and mounting the receiving member on the elastic member, the TAB is pressed onto the liquid crystal cell so that the receiving member follows the pressing head when the pressing head operates. A TAB pressure bonding device for a liquid crystal cell, which has a structure. 2. The receiving member is mounted in a frame member through a rubber sheet, the receiving member having a receiving surface against which the lower surface of the liquid crystal cell abuts, so that the pressing force of the pressure head acts in the direction. The TAB pressure bonding apparatus for a liquid crystal cell according to claim 1, wherein the TAB pressure bonding apparatus has a displaceable structure. 3. The receiving member is configured such that both ends of the receiving member are fixed to a mounting member, and an intermediate portion is mounted so as to be forcibly bendable by an adjusting bolt screwed into the mounting member. The TAB pressure bonding device for a liquid crystal cell according to claim 1 or 2. 4. A pressing member which presses the liquid crystal cell from above when pressing by the pressing head and absorbs deformation in the direction along the thermocompression bonding line. 1. A TAB pressure bonding device for a liquid crystal cell according to 1.