JPH0493041A - Thermocomprerssion bonding method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Summary] Regarding a method for thermocompression bonding of leads using a thermoplastic anisotropic conductive resin film, the present invention aims to eliminate the effects of heating the resin film and thermal expansion of a pressing plate serving as a cooling medium. For the purpose of simultaneously connecting a large number of external connection electrodes formed on a substrate and a large number of leads facing each of the connection electrodes by thermocompression bonding using a thermoplastic anisotropic conductive resin film,
While the substrate and the lead are being set on the thermocompression bonding table, a metal press plate is placed on each of the substrates and the leads, which serves as a heating medium when the heated wedge heats the resin film and also as a cooling medium when cooling the resin film. The present invention is characterized in that a heating means is sandwiched between the wedge and the heater block for preheating.

[Industrial application field]

The present invention relates to a thermocompression bonding method, in particular, a thermocompression bonding method using a thermoplastic anisotropically conductive resin film.
edBondin) and how to connect the leads of the frame.

[Conventional technology]

FIG. 4 is a schematic plan view of a crimp part connecting a large number of leads of a T A B frame to a liquid crystal panel.
A plurality of (five in the figure) TAB frames 3-1 to 3-5 are bonded by thermocompression at the same time.

Each TAB frame 3-1 to 3-5 is formed by connecting one end of a large number of leads 4 facing each of the connecting electrodes 2 to a connecting member 5, and each After connecting the end connecting portion of the REET 4 to the connecting terminal 2, it is cut along the line AA in the figure and the connecting member 5 is removed.

The resin film 6 has a structure in which a large number of metal-coated particles are built into an acrylic ball with a diameter of about 10 μm, for example, and the resin film 6 has a structure in which a large number of metal-coated particles are built into an acrylic ball with a diameter of about 10 μm.
When the resin film 6 is heated to a thermoplastic temperature and an appropriate pressing force is applied, conductivity can be obtained between the connecting electrode 2 and the lead 4 facing each other.

FIG. 5 is an explanatory diagram of the conventional method of thermocompression bonding using a conventional device.

In FIG. 5, after fixing the liquid crystal panel 1 to the upper surface of the thermocompression bonding table 13 attached to the base plate 12 and overlaying the resin film 6 on the connection electrode 2, the connection part of the lead 4 is placed opposite the connection electrode 2. TA on the resin film 6 as shown.
Stack and fix B frame 3.

A metal pressing plate 9 hangs vertically below the crimp wedge 8 that moves up and down, and when the wedge 8 heated by a built-in heater or the like is lowered toward the TAB frame 3, as shown in FIG.
As shown in (a), the wedge 8 presses the TAB frame 3 with an appropriate pressing force via the press plate 9, and heats the TAB frame 3 and the resin film 6 via the press plate 9.

As a result, the connection electrode 2 and the lead 4 of the TAB frame 3 are electrically connected by the resin film 6, but the resin film 6 is in a softened state at this point.

Therefore, as shown in FIG. 5 (I+), after raising the wedge 8 with the pressing plate 9 left in place, the cold air 12 is blown onto the pressing plate 9 from the nozzle 11 located diagonally above. Cools and solidifies, connecting electrode 2 and lead 4
The connection is completed.

Next, as shown in FIG. 5(C), the wedge 8 and the pressing plate 9 are
is lifted upward, and a new liquid crystal panel 1 is set on the thermocompression bonding table 13 in place of the liquid crystal panel 1 that has been crimped.

Thereafter, the TAB frame 3 is thermocompression bonded to a large number of liquid crystal panels 1 by repeating the above steps.

FIG. 6 is a diagram showing the relationship between the cycle time of thermocompression bonding using the apparatus shown in FIG. 5 and the temperature of the press plate.

In FIG. 6, the vertical axis represents the temperature ('C) of the press plate 9.

The horizontal axis is time (seconds), and the temperature of the press plate 9, which was about 140°C during thermocompression bonding, decreased to below ioo'c in about 20 seconds when setting the new liquid crystal panel 1, and once For thermocompression bonding, the net time for thermocompression bonding is approximately 10 seconds, the cooling time after thermocompression bonding is approximately 30 seconds, the first compression preparation (replacing the liquid crystal panel 1, etc.) is approximately 25 seconds, and the heating of the press plate 9 is approximately 10 seconds. seconds, and their total time is about 75 seconds.

[Problems to be Solved by the Invention] In the conventional method described above, the pressing plate 9, which is a heating medium and a cooling medium for the resin film 6, has a length spanning almost the entire width of the liquid crystal panel 1. During the exchange, it is cooled by about 50°C from the thermocompression bonding temperature, and at the beginning of the next thermocompression bonding process, which is sandwiched between the wedge 8 and the TAB frame 3, the longitudinal direction indicated by arrows C and C' in FIG. It begins to thermally expand.

Therefore, applying conventional thermocompression bonding to liquid crystal panels,
For example, when five TAB frames 3-1 to 3-9 on which 160 leads are formed at a pitch of 0.18 mm are bonded simultaneously to the same panel 1 by thermocompression, the TAB frames 3-
The thermal expansion of the pressing plate 9 that presses 1 to 3-5 is TAB
While the comb-like leads 4 of the frames 3-1 to 3-3 are biased by several tens of μm in the length direction of the press plate 9 (in the direction of arrows B and B' in FIG. 4), the connections formed in the base Since the electrode 2 is hardly affected by the thermal expansion of the pressing plate 9, the lead 4 at the end, for example, the lead 4 at the left end of the frame 3-1 and the frame 3
The right end lead 4 of -s is now shifted with respect to the opposing connection part 2.

Due to this deviation of the lead 4, the TAB frames 3-1 to 3-5
．． When the manufacturing error of the connection electrode 2 is added, the deviation between the connection part 2 and the lead 4 may be 90 μm, and as a result,
There was a problem that some leads 4 were not connected.

[Means for Solving the Problems] The thermocompression bonding method of the present invention, which aims to eliminate connection failures due to thermal expansion of a press plate, is as follows: According to FIGS. 1 and 2, which show examples thereof, (Substrate) A large number of external connection electrodes formed on 1 and a large number of leads facing each of the connection electrodes,
When simultaneously connecting by thermocompression bonding using thermoplastic anisotropically conductive resin film 6, the heated wedge 8 serves as a heating medium when heating the resin film 6, and also as a cooling medium when cooling the resin film 6. A metal pressing plate 9 is sandwiched between a wedge 7 and three heater blocks, each having a heating means, and preheated while the panel 1 and the lead are being set on the thermocompression bonding table 13. do.

(Function) According to the above means, while the panel and the leads are set on the thermocompression bonding table, the pressing plate is preheated by the wedge and the heater block, each having a heating means.Therefore, the pressing plate that presses the lead is preheated. is almost at the crimping temperature when it contacts the lead, and thermal expansion during crimping is significantly lower than in conventional methods, making it possible to eliminate connection failures in conventional methods and shortening the cycle time of thermocompression bonding.

〔Example〕

EMBODIMENT OF THE INVENTION Below, the thermocompression bonding method by the Example of this invention is demonstrated using drawing.

FIG. 1 is a front view showing the main structure of the thermocompression bonding device according to the present invention, FIG. 2 is an explanatory diagram of a thermocompression bonding method using the device shown in FIG. 1, and FIG. 3 is a diagram showing the device shown in FIG. It is a figure which shows the relationship between the cycle time of the thermocompression bonding used, and the temperature of a press plate.

In FIG. 1, wedge 8 is connected to heater plate 21.
The heater plate is attached by hanging from a holder 24 via a tool 22 and a plurality of shafts 23. The holder 24 is fixed to a drive shaft 26 of an air cylinder 25, and a support fitting 27 to which the air cylinder 25 is fixed is supported by a column 28.

The press plate 9 is fixed to a support 29 made of a thermally insulating material, and the support 29 is located below the wedge 8 when not in operation.
is suspended from the holder 24 by a plurality of coil springs 30.

Sliding base 32 that slides in the left-right direction along the top surface of base 31
On top is a thermocompression table 1 for fixing the liquid crystal panel 1.
3 and a heater block 33, and the heater block 33 has a built-in heater 34.

In this device, the liquid crystal panel 1 is fixed on a sliding table 32, a thermoplastic anisotropically conductive resin film 6 is placed on the connection electrode 2 at the right end of the surface of the liquid crystal panel 1, and the leads 4 are placed opposite the connection electrode 2. After the TAB frame 3 is superimposed and fixed on the resin film 6, the air cylinder 25 is driven to lower the holder 24.

Then, the pressing plate 9 presses the TAB frame 3, and in turn, the wedge 8 presses the pressing plate 9. Next, when the air cylinder 25 is reversely driven to raise the holder 24,
In the first stage, only the wedge 8 rises, and in the second stage, the press plate 9 separates from the TAB frame 3 and rises.

Furthermore, when the right end of the sliding table 32 is brought into contact with the stopper 35, the TAB frame 3 is located under the pressing plate 9, and when the left end is brought into contact with the stopper 36, the heater block 33 is located under the pressing plate 9. To position.

In FIG. 2(A), the heated wedge 8 is placed on the pressing plate 9.
Press TAB frame 3 through
The resin film 6 sandwiched between the AB frames 3 is heated.

As a result, connection electrodes 2 formed on the surface of the liquid crystal panel 1
and the leads 4 of the TAB frame 3 are electrically connected by the softened resin film 6.

In FIG. 2(D), after the wedge 8 is raised leaving the press plate 9, cold air 12 is blown onto the press plate 9 from the diagonally upward nozzle 11, and the resin film 6 is cooled through the press plate 9. It solidifies, and the connection between the connection electrode 2 and the lead 4 is completed.

Next, as shown in FIG. 2(C), the pressing plate 9 is lifted above the TAB frame 3 by raising the holder 24, and then the sliding table 31 is moved to the left and the holder 24 is lowered. As shown in (d), the press plate 9 cooled by the cold air 12 is sandwiched between the heated wedge 8 and the heater block 33, and is preheated to a thermocompression bonding temperature.

Thereafter, while the press plate 9 is being preheated, a new liquid crystal panel 1 is set in place of the panel 1 that has been bonded, and the above steps are repeated to heat and press the TAB frame 3 onto a large number of liquid crystal panels 1 one after another.

In Fig. 3, the vertical axis is the temperature of the press plate 9 (°C), and the horizontal axis is the time (seconds). The temperature drops to below 100°C in about 20 seconds, and one thermocompression bonding takes about 30 seconds to prepare for crimping, such as replacing a new LCD panel 1, and the net time of thermocompression bonding is about 10 seconds. The cooling time is about 30 seconds, and the total time is about 70 seconds, and the pressing plate 9
Preheating is performed during preparation for crimping.

In FIGS. 2 and 3, the press plate 9, which has been preheated during replacement of the new liquid crystal panel 1, can start thermocompression bonding almost at the same time as pressing the TAB frame 3 with the pressing force of the wedge 8, and The temperature rise after contacting the TAB frame 3 is about 20 to 30°C, and the thermal expansion in the length direction is small (about 20 μm or less), so the leads 4 of the TAB frame 3 are bonded by thermocompression with almost no movement. Become.

〔Effect of the invention〕

As explained above, according to the method of the present invention, it is possible to significantly reduce the movement of the lead due to thermal expansion of the pressing plate, eliminate the conventional crimping defects, and reduce the cycle time of thermocompression bonding, improving productivity. effective.

[Brief explanation of drawings]

Fig. 1 is the main configuration of the thermocompression bonding device according to the present invention, Fig. 2 is an explanatory diagram of the thermocompression bonding method using the device shown in Fig. 1, and Fig. 3 is thermocompression bonding using the device shown in Fig. 1. Figure 4 is a diagram showing the relationship between cycle time and temperature of the pressing plate. Figure 4 is a schematic plan view of the thermocompression connection between the liquid crystal panel and the TABIJ-board. Figure 5 is an explanatory diagram of the conventional thermocompression bonding method. Figure 6 is FIG. 7 is a diagram showing the relationship between the cycle time of thermocompression bonding using a conventional device and the temperature of the press plate. FIG. 7 is a perspective view of the press plate. In the figure, 1 is the liquid crystal panel (substrate), 2 is the external connection electrode of the substrate 1, 3 +3-1+3-2+3-3+3-4+3-5 is TA
B frame, 4 is a lead, 6 is a thermoplastic anisotropic conductive resin film, 9 is a wedge, 9 is a press plate, 13 is a thermocompression bonding table, 33 is a heater block. residence

Claims (1)

[Claims] A large number of external connection electrodes (2) formed on a substrate (1) and a number of leads (4) facing each of the connection electrodes (2).
) are simultaneously connected by thermocompression bonding using a thermoplastic anisotropically conductive resin film (6), when the heated wedge (8) is used as a heating medium to heat the resin film (6). Along with the resin film (6)
When cooling the substrate (1) and the leads (4), a metal press plate (9) that serves as a cooling medium is placed on the thermocompression table (1).
3) A thermocompression bonding method characterized in that during setting, preheating is performed by sandwiching the wedge between the wedge (8) and the heater block (3), each of which has a heating means.