JP2003298226A - Substrate connecting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable a substrate connecting device to obtain a prescribed connection quality to each substrate pair even when the substrate pair has a different thickness when simultaneously heating and pressing a plurality of substrate pairs piled upon another with an anisotropic conductive material being interposed between the electrode lead sections of each two substrates. <P>SOLUTION: When simultaneously heating and pressing two substrates by interposing the anisotropic conductive material between the electrode lead sections of the substrates by means of an anvil plate disposed on a base side 10 and a vertically movable thermocompression bonding head, the anvil plate is divided into a plurality of independent vertically movable lower blades 141 and 142 and the blades 141 and 142 are elastically supported by means of lower blade supporting means 40 (for example, rubber-made cushioning materials 41) in vertically movable states. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a substrate connecting device for connecting electrode lead portions of two substrates via an anisotropic conductive material, and more specifically, for connecting a plurality of substrate pairs at the same time. The present invention relates to a technique for making the thermocompression bonding conditions for each substrate pair substantially the same.

[0002]

2. Description of the Related Art Anisotropic conductive film (ACF; anisotro) is used as an anisotropic conductive material which is one of electrical connecting means.
pic conductive film) and anisotropic conductive resin (ACA; anisotropic con)
inclusive (adhesive). Among them, the anisotropic conductive film is, for example, a film in which conductive particles are dispersed in a thermosetting resin film, and has a property of exhibiting unidirectional conductivity when it is thermocompression bonded.

In the field of liquid crystal display devices, an anisotropic conductive film includes, for example, an electrode lead portion formed in a terminal portion of a liquid crystal panel and a TCP (tape carrier).
package) and the electrode lead parts of the flexible substrate are electrically connected together.

A substrate connecting device using an anisotropic conductive film includes an anvil plate arranged in a holding groove of a base and a thermocompression head which can be moved up and down with respect to the anvil plate.
Place the pair of substrates with the anisotropic conductive film sandwiched between the electrode leads of the two substrates on the anvil plate, and then press the thermocompression bonding head from above to push the electrode leads of the substrate pair together. Connect via an anisotropic conductive film.

In order to improve the productivity, it is preferable to connect a plurality of substrate pairs at the same time in one thermocompression bonding operation. Figure 5
FIG. 1 shows a conventional example of a board connecting device for simultaneously connecting two board pairs. 5A is a plan view and FIG. 5B is FIG. 5A.
5 is a sectional view taken along the line CC of FIG. 5, and FIG. 5C is a sectional view taken along the line DD of FIG. The board connection device described here is
This is for connecting a flexible substrate such as TCP to the terminal portion of the liquid crystal panel.

The board connecting device 1 includes a base 10 including a metal base plate 11 and two tables 12 and 13 installed on the base plate 11. One table 12 is for supporting a liquid crystal panel, and the other table 13 is for supporting a flexible substrate. In this example, both of them have a size capable of juxtaposing two substrates.

An anvil plate 14 made of a single metal plate is sandwiched between the tables 12 and 13. FIG. 5 (c)
As shown in FIG.
0 is provided. The thermocompression bonding head 20 is made of one metal plate having the same length as the anvil plate 14, and includes an electric heater (not shown).

The thermocompression bonding head 20 can be moved up and down, and is pressed against the anvil plate 14 with a predetermined pressure by a driving means such as an air cylinder (not shown). A cushion material 21 having a thickness of 0.2 mm for silicon rubber and a thickness of 0.05 mm for tetrafluoroethylene resin is attached to the pressing surface of the thermocompression head 20.

To explain an example of the connection work procedure, first,
The two liquid crystal panels PL1 and PL2 are placed on one table 12 so that their terminal portions are located on the anvil plate 14.
Then, an anisotropic conductive film (not shown) is arranged on each terminal portion.

Next, two flexible substrates FP1 and F
P2 is juxtaposed on the other table 13, and the electrode lead portions thereof are arranged on the liquid crystal panel PL via the anisotropic conductive film.
1, PL2, and then the thermocompression bonding head 20 is lowered and pressed down from above the flexible substrates FP1 and FP2 with a predetermined pressure.

[0011]

Accordingly, the flexible substrate FP is provided for the two liquid crystal panels PL1 and PL2.
1 and FP2 are simultaneously thermocompression bonded via the anisotropic conductive film, but this has the following problems to be solved.

That is, in the case of the liquid crystal panel, the substrate thickness (thickness of the terminal portion) has a variation of about 70 μm at the maximum. FIG. 5C shows a case where the liquid crystal panel PL1 on one side is thick and the liquid crystal panel PL2 on the other side is thin.

For example, the substrate thickness of the liquid crystal panel is 20 μm
If the degree is different, the cushion material 21 of the thermocompression bonding head 20
Only with this, it becomes impossible to absorb the pressure difference between the liquid crystal panels PL1 and PL2 during the pressure bonding. As a result, the liquid crystal panel having a large thickness has excessive pressure, and the liquid crystal panel having a small thickness has insufficient pressure, so that a predetermined connection quality cannot be maintained.

Such a problem is not limited to the connection between the liquid crystal panel and the flexible substrate, but also in the connection between the flexible substrate and the hard circuit substrate or the connection between the hard circuit substrates by the anisotropic conductive film. Occurs.

The present invention has been made to solve the above problems, and its object is to simultaneously heat a plurality of substrate pairs in which anisotropic conductive films are sandwiched between two electrode lead portions of two substrates. It is an object of the present invention to provide a board connecting device capable of obtaining a predetermined connection quality for each board pair even when the thickness of each board pair varies in pressure bonding.

[0016]

In order to achieve the above object, the present invention comprises an anvil plate arranged in a holding groove of a base and a thermocompression head capable of moving up and down with respect to the anvil plate. A plurality of substrate pairs stacked with an anisotropic conductive material sandwiched between the electrode lead portions of the two substrates are juxtaposed on the anvil plate, and the thermocompression bonding head is lowered to bring the electrode lead portions of the substrate pair to each other. In the substrate connecting device for simultaneously connecting via the anisotropic conductive material, as the anvil plate, provided with a plurality of lower blades movable in the vertical direction and independently provided for each of the substrate pairs. In addition, lower blade supporting means for elastically supporting the lower blades so as to be vertically movable is provided at the bottom of the holding groove.

According to this structure, since the lower blade supporting means absorbs the pressure imbalance of each substrate pair due to the difference in substrate thickness, even when a plurality of substrate pairs are heated and pressure-bonded at the same time, It is possible to maintain a predetermined connection quality for the pair.

Although each lower blade is made of a metal plate such as stainless steel, it does not have a cutting function. Further, in the present invention, the board pair means two members connected via an anisotropic conductive material, and is a combination of a liquid crystal panel and a flexible board, a combination of a flexible board and a hard circuit board, and a hard circuit. A combination of substrates is included.

In the present invention, in order to simplify the structure, it is preferable to use a rubber elastic body for the lower blade supporting means. In order to adjust the elastic supporting force of each lower blade according to the difference in the substrate thickness, a spring having a spring strength adjusting mechanism may be used as the lower blade supporting means.

Further, in order to apply a uniform pressure to each substrate pair, an oil cylinder is provided below each lower blade, and a hydraulic damper communicating between the oil cylinders is supported by the lower blade. It is preferable to adopt it as a means. In order to make the movement of each lower blade smooth, it is preferable to provide a low friction means such as a bearing ball on the inner wall of the holding groove.

It is not preferable to divide the thermocompression bonding head side because not only an electric heater is required for each thermocompression bonding head but also it becomes difficult to uniformly control the temperature of each thermocompression bonding head.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a board connecting device 1A according to the present invention.
The embodiment of the present invention will be described with reference to FIG. 1A is a plan view, and FIG. 1B is A in FIG.
FIG. 1C is a sectional view taken along line BB in FIG. 1C. The thermocompression bonding head is not shown in FIG. In addition,
In this embodiment, an anisotropic conductive film is used as the anisotropic conductive material, but an anisotropic conductive resin can also obtain the same effect.

The board connecting apparatus 1A according to this embodiment also
Similar to the conventional example described above, a combination of a liquid crystal panel and a flexible substrate such as TCP is connected to each other, and a metal base plate 11 and two tables 12 installed on the base plate 11 are connected. , 10 including base 13
Is equipped with.

One table 12 is for supporting a liquid crystal panel, and the other table 13 is for supporting a flexible substrate. In this example, both of them are formed in a size capable of juxtaposing two substrate pairs. Base plate 11 and table 12, 1
3 may be integrated.

An anvil plate is arranged between the tables 12 and 13. In this example, two lower blades are used as the anvil plate,
That is, the lower blade 141 for one substrate pair and the lower blade 142 for the other substrate pair are used. Lower blade 141,142
Are movable independently of each other and are made of a metal plate such as stainless steel.

Holding grooves 30 and 30 for holding the lower blades 141 and 142 between the facing surfaces of the tables 12 and 13 respectively so as to be movable in the vertical direction (direction orthogonal to the paper surface in FIG. 5A).
Are formed. The bottom of each holding groove 30 is closed by the base plate 11.

Further, lower blade guide rails 31 for guiding the lower blades 141, 142 in the vertical direction are provided at two locations on both sides of the tables 12, 13 and at one location in the center. Each of the lower blade guide rails 31 is formed with a guide groove 311 that holds the side edges of the lower blades 141 and 142.

In each of the guide grooves 311 is shown in FIG.
As shown in (b) and (c), bearing balls 312 are provided as low friction members that smoothen the movement of the lower blades 141 and 142. In addition, bearing ball 3
Instead of 12, the lower blade guide rail 31 itself may be formed of a low friction resin, or the guide groove 311 may be coated with a low friction resin.

At the bottom of each holding groove 30, the lower blades 141, 1
Lower blade support means 40 for elastically supporting 42 are provided. The lower blade support means 40 eliminates the pressure difference caused by the difference in thickness between two substrate pairs (refer to the liquid crystal panel PL and the flexible substrate FP shown in FIG. 5 above) at the same time when they are thermocompression bonded. Acts as a damper to absorb.

In this example, a rubber cushion material 41 is used as the lower blade supporting means 40. Cushion material 41
The hardness and the thickness depend on the pressure applied at the time of crimping, but generally the hardness is Shore hardness 60 to 90 and the thickness is 0.5.
It is preferably about 1.0 mm. In this example, the cushion material 41 is two pieces for the lower blade 141 and the lower blade 142, but one cushion material 41 may be arranged between the lower blade 141 and the lower blade 142.

In FIG. 2, on one lower blade 141, one substrate pair A in which a flexible substrate FP1 is superposed on the terminal portion of the liquid crystal panel PL1 via an anisotropic conductive film is placed, and the other lower blade is placed. A state in which the other substrate pair B in which the flexible substrate FP2 is overlapped on the terminal portion of the liquid crystal panel PL2 via the anisotropic conductive film (both not shown) is placed on 142, and crimped by the thermocompression bonding head 20. Is illustrated.

As illustrated here, even if the thicknesses of the connection portions of the one substrate pair A and the other substrate pair B are different,
According to the present invention, the difference in thickness is absorbed by the amount of deformation of the cushion material 41, and the pressure from the thermocompression bonding head 20 is evenly applied to each substrate pair A and B. , B can ensure a predetermined connection quality.

Incidentally, the thickness of the substrate pair A and the substrate pair B is 20
When there is a difference of μm, in the case of the anvil plate 14 made of one metal plate of the above-mentioned conventional example, almost no predetermined connection quality could be obtained, but the split lower blade 14 according to the present invention.
In the case of 1,142, it was possible to obtain a predetermined connection quality for all the substrate pairs.

FIG. 3 shows a first modification of the lower blade supporting means 40 of the lower blades 141 and 142. In the first modification, the compression spring 42 having the spring strength adjusting means is adopted. In this case, the spring strength adjusting means is screwed to the nut 43 fixed to the base plate 11 and the nut 43 so that the tip thereof is the lower blade 14.
1, 142 is connected to the adjusting screw 44, and the compression spring 42 is inserted into the adjusting screw 44.
1 and the lower blades 141 and 142.

According to this, by rotating the adjusting screw 44, the elastic biasing force with respect to the lower blades 141, 142 of the compression spring 42 can be arbitrarily adjusted. The number of adjusting screws 44 provided for each lower blade may be arbitrary. The spring strength adjusting means can be applied to the case where the lower blade supporting means 40 is the rubber cushion material 41.

FIG. 4 shows a second modification of the lower blade supporting means 40 of the lower blades 141 and 142. In this second modified example, a hydraulic damper system is adopted. That is, the oil cylinder 45 for the lower blade 141 and the lower blade 1 which communicate with each other through the pipe 47 having the flow rate adjusting valve 471 in the base plate 11.
An oil cylinder 46 for 42 is provided, and one lower blade 141 is supported by the piston 451 of the oil cylinder 45, and the other lower blade 142 is supported by the piston 461 of the oil cylinder 46.

According to this hydraulic damper system, as illustrated in FIG. 2, the thickness of the substrate pair A arranged on the lower blade 141 side is thick and the thickness of the substrate pair B arranged on the lower blade 142 side is thin. In this case, since the lower blade 141 side is pushed down, the lower blade 14
Since the second side is pushed up, the upper surfaces of the substrate pair A and B are aligned on the same plane, and even pressure is applied to both connection portions.

The present invention is not limited to the above embodiment. By changing the size of the tables 12 and 13, the number of substrate pairs that can be connected in one operation can be arbitrarily determined. In some cases, the lower blade itself can be made to have a cushioning property by making the lower blade from rubber, for example.

[0039]

As described above, according to the present invention,
For simultaneously thermocompression bonding a plurality of substrate pairs with an anisotropic conductive material sandwiched between the electrode lead portions of the two substrates by an anvil plate arranged on the base side and a thermocompression head that can move up and down By dividing the anvil plate into a plurality of independent lower blades that can move in the vertical direction and elastically supporting each of the lower blades in a vertically movable manner by the lower blade supporting means,
Even if there is variation in the thickness of each board pair, each board pair can be satisfactorily connected while maintaining a predetermined connection quality.

[Brief description of drawings]

FIG. 1 is a plan view and a cross-sectional view for explaining an embodiment of a board connecting device according to the present invention.

FIG. 2 is an explanatory view of the operation of the present invention.

FIG. 3 is a cross-sectional view showing a first modification of the lower blade support means in the present invention.

FIG. 4 is a cross-sectional view showing a second modification of the lower blade support means in the present invention.

5A and 5B are a plan view and a cross-sectional view for explaining a board connecting device as a conventional example.

[Explanation of symbols]

10 bases 11 base plate 12, 13 tables 141,142 lower blade 30 retaining groove 31 Lower blade guide rail 311 Guide groove 312 bearing balls 40 Lower blade support means 41 cushion material 42 Compression spring 43 fixing nut 44 Adjustment screw 45,46 Oil cylinder 451 and 461 pistons 47 plumbing 471 Flow control valve

Claims (5)

[Claims] 1. An anisotropic conductive material including an anvil plate disposed in a holding groove of a base and a thermocompression bonding head capable of moving up and down with respect to the anvil plate, between electrode lead portions of two substrates. Substrate connection in which a plurality of substrate pairs stacked with sandwiching the substrate are juxtaposed on the anvil plate, and the thermocompression bonding head is lowered to simultaneously connect the electrode lead portions of the substrate pair with each other through the anisotropic conductive material. In the device, the anvil plate is provided with a plurality of lower blades that are movable in the vertical direction and are independently provided for each of the substrate pairs, and the lower blades are provided at the bottom of the holding groove. A board connecting device, characterized in that a lower blade supporting means for elastically supporting up and down movement is provided. 2. The board connecting device according to claim 1, wherein the lower blade supporting means is made of a rubber elastic body. 3. The board connecting device according to claim 1, wherein the lower blade supporting means is a spring having a spring strength adjusting mechanism. 4. The board connecting device according to claim 1, wherein the lower blade supporting means is a hydraulic damper. 5. The substrate connecting device according to claim 1, wherein low friction means for the lower blade is provided on an inner wall of the holding groove.