JPH10303256A - Tape carrier connection method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the amount of extension of a tape carrier upon heat pressing by performing the heat pressing such that when a temperature applied to an anisotropic-conductive adhesive sheet becomes a particular ratio of a final temperature, a pressure force applied to the anisotropic-conductive adhesive sheet is a particular ratio of a final pressure force. SOLUTION: A connection terminal 6 of a tape carrier 5 and an Al electrode 2 of a liquid crystal display panel 1 are aligned with each other via an anisotropic-conductive adhesive sheet 3, and heat-pressed by a constant-heating type bonding tool 7 from a position over the tape carrier 5, such that the terminal 6 and the electrode 2 are electrically connected. In this case, the heat pressing is performed such that when the temperature applied to the sheet 3 reaches 85% of the final temperature the pressure force applied to the sheet 3 is 80 to 85% of the final pressure force. By this arrangement, the rising of the pressure force applied to the sheet 3 is quickened, and the sheet 3 can be pressurized with a pressure force close to the final pressure force before the carrier 5 extends by the heat applied to the carrier 5. Thus, the amount of extension of the carrier 5 can be suppressed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for connecting a tape carrier to an electronic device substrate such as a liquid crystal display panel or a printed circuit board.

[0002]

2. Description of the Related Art In general, there are a variety of methods for connecting a semiconductor element to an electronic device substrate such as a liquid crystal display panel or a printed circuit board. For example, as a mounting method of a liquid crystal driving LSI in a liquid crystal display device, COG is used. (Chi
p On Glass) method, TAB (Tape Au)
(bonded bonding) method is known.

In the COG method, a protruding electrode of a liquid crystal driving LSI and an electrode of a liquid crystal display panel are directly connected via an anisotropic conductive adhesive sheet.

On the other hand, the TAB method connects an LSI for driving a liquid crystal to a liquid crystal display panel via a tape carrier, so that electrical characteristics can be inspected on the tape, and the tape can be folded and mounted three-dimensionally. There are features. That TAB
Even in the mounting method by the construction method, a method of connecting an electrode of a liquid crystal display panel and a connection terminal of a tape carrier using an anisotropic conductive adhesive sheet is generally used, and the anisotropic conductive adhesive sheet is heat-cured. The conductive particles are dispersed in an adhesive made of a conductive resin, and the electrode pitch for connection is 70 μm.
A good connection can be made to the extent.

The connection between the electrode of the liquid crystal display panel and the connection terminal of the tape carrier by the TAB method is performed by temporarily fixing an anisotropic conductive adhesive sheet to the electrode surface of the liquid crystal display panel and connecting the electrode of the liquid crystal display panel to the tape carrier. Align the terminals. Thereafter, the tape carrier is heated and pressed by a bonding tool, and the bonding tool is removed after a predetermined time. By applying heat and pressure, the conductive particles having elasticity contained in the anisotropic conductive adhesive sheet are compressed, and the electrodes of the liquid crystal display panel and the connection terminals of the tape carrier are electrically stably connected. In addition, the connection is reliably maintained by the curing of the adhesive of the anisotropic conductive adhesive sheet.

As means for applying heat and pressure by a bonding tool, there are a pulse heating type tool, a constant heating type tool, and the like. The pulse heating method is a method in which a pulse current is instantaneously passed to a bonding tool to heat the bonding tool to a predetermined temperature. Although the temperature setting can be easily adjusted in a plurality of steps, the price of the pulse power source is higher and it is difficult to produce a long heat press tool as compared with the constant heating method. On the other hand, in the continuous heating method, the temperature setting of the hot press tool cannot be changed instantaneously and freely, but the price of the power supply is very low and long heat press tools can be easily manufactured. Is the mainstream.

In general, as a device for aligning the electrodes of the liquid crystal display panel with the connection terminals of the tape carrier, both the electrodes of the liquid crystal display panel and the connection terminals of the tape carrier are recognized by a CCD camera, and the output signal is used in accordance with the output signal. There are many mechanical alignment methods, and the alignment accuracy is ± 5 ±±
10 μm has been achieved.

[0008]

However, in the connection by the conventional continuous heating method, since the bonding tool is lowered by the air cylinder, a time lag occurs until pressure is transmitted to the anisotropic conductive adhesive sheet. on the other hand,
Since the temperature applied to the anisotropic conductive adhesive sheet is constantly heated, it rises simultaneously with the contact between the bonding tool and the tape carrier. There is a problem that the amount of elongation of the tape carrier changes due to the difference between the rise in temperature and pressure applied to the anisotropic conductive adhesive sheet.

In recent years, there has been a demand for a liquid crystal display panel with a higher resolution, and the TAB method has more outputs, so that the pitch of the connection terminals has been reduced. For this reason, it is important to control the elongation of the tape carrier during hot pressing.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned conventional problems and to provide a method of connecting a tape carrier with a high yield that can be connected at a narrow pitch and has high reliability.

[0011]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a method in which a connection terminal of a tape carrier and an electrode of an electronic device substrate are opposed to each other via an anisotropic conductive adhesive sheet.
When the temperature applied to the anisotropic conductive adhesive sheet reaches 85% of the ultimate temperature when applying heat to the tape carrier from the upper surface of the tape carrier with a bonding tool, the pressure applied to the anisotropic conductive adhesive sheet becomes the final ultimate pressure. This is a method of connecting a tape carrier that is thermally pressurized so as to be 80% or more and 85% or less. It is possible to suppress the amount of elongation of the tape carrier during the heat pressurization, and to connect the electrode of the electronic device substrate to the connection terminal of the tape carrier. The positioning accuracy is improved, and even when the connection terminals of the tape carrier have a narrow pitch, a high yield and high reliability can be secured.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS According to a first aspect of the present invention, a connection terminal of a tape carrier and an electrode of an electronic device substrate are opposed to each other via an anisotropic conductive adhesive sheet, and a tape is formed by a bonding tool. When the temperature applied to the anisotropic conductive adhesive sheet reaches 85% of the ultimate temperature when applying heat and pressure from the upper surface of the carrier, the pressure applied to the anisotropic conductive adhesive sheet is 80% to 85% of the ultimate pressure. This is a method of connecting a tape carrier to be heated and pressed as described below, and the temperature applied to the anisotropic conductive adhesive sheet is set to a final attainment temperature of 8
When the pressure applied to the anisotropic conductive adhesive sheet reaches 5%, the pressure applied to the anisotropic conductive adhesive sheet is increased by 80% to 85% of the ultimate pressure. Before the tape carrier expands due to the heat applied to the tape carrier, the anisotropic conductive adhesive sheet can be pressed at a pressure close to the ultimate pressure, and the amount of expansion of the tape carrier can be suppressed.

According to a second aspect of the present invention, there is provided the tape carrier connecting method according to the first aspect, wherein the method of thermally pressing the upper surface of the tape carrier with a bonding tool is a constant heating method. In a constant heating method that is very inexpensive and can easily produce a long hot press tool, the amount of elongation of the tape carrier can be suppressed.

An embodiment of the method for connecting a tape carrier according to the present invention will be described below with reference to the drawings.

(Embodiment) FIG. 1 is a sectional view of a tape carrier connecting method according to an embodiment of the present invention before a tape carrier and a liquid crystal display panel are connected before heat pressing.
FIG. 2 is a cross-sectional view of the tape carrier and the liquid crystal display panel according to the embodiment at the time of heat pressing in a connecting step.
Is a liquid crystal display panel made of a light-transmitting glass substrate, on which a 2000-3000 ° thick Al electrode 2 is formed, and 3 is an Al electrode 2 of the liquid crystal display panel 1. On the surface of the crimping temperature is 100-15
This is an anisotropic conductive adhesive sheet in which conductive particles 4 are dispersed and adhered in a temporary fixing state at 0 ° C. The anisotropic conductive adhesive sheet 3 uses CP7621F manufactured by Sony Chemical Co., Ltd. As shown in FIG. 1, 4 is dispersed and arranged in an anisotropic conductive adhesive sheet 3 made of a thermosetting adhesive or the like. By arranging the conductive particles 4 or more, a stable connection resistance (0.5 Ω or less) can be realized. 5 is
A connection terminal 6 provided on the surface of the tape carrier is positioned and overlapped with the Al electrode 2 of the liquid crystal display panel 1 via the anisotropic conductive adhesive sheet 3.
Is a constant heating type bonding tool which is superimposed on the tape carrier 5 via a 50 μm-thick Teflon sheet 8 as a cushion material for more uniformly applying heat and pressure.

The connection method of the tape carrier according to the above arrangement is such that the connection terminals 6 of the tape carrier 5 and the Al electrodes 2 of the liquid crystal display panel 1 face each other via the anisotropic conductive adhesive sheet 3, and are aligned and overlapped. Thereafter, heat is applied from above the tape carrier 5 with a bonding tool 7 of a constant heating method, and the connection terminals 6 of the tape carrier 5 and the Al electrodes 2 of the liquid crystal display panel 1 are electrically connected.

In the above-described method of connecting the tape carriers, the lowering speed of the bonding tool 7 was connected under the respective conditions shown in Table 1 to obtain samples 1, 2, and 3.

[0018]

[Table 1]

The temperature, pressure and time at the time of connection were 19 for all of Samples 1, 2 and 3.
The same conditions were set at 0 ° C., 40 kgf / cm ² and 20 sec.

Next, in each of the above samples, how the temperature change (%) with respect to the ultimate temperature changes with the elapsed time is shown in Table 2, and the pressure change (%) with respect to the ultimate pressure is shown. (Table 3) shows how the time changes with the elapsed time.
Further, based on (Table 2) and (Table 3), for sample 1, the heat pressurization time, the final attained temperature, and the ratio of the temperature change and the pressure change to the final attained pressure are shown in FIG. FIGS. 4 and 5 are time-temperature and pressure change diagrams of Samples 2 and 3, respectively.

[0021]

[Table 2]

[0022]

[Table 3]

The elongation of the tape carrier 5 due to heat and pressure was measured using the sample prepared as described above. As shown in the tape carrier sectional view of FIG. 6, the extension amount of the tape carrier 5 is determined by the distance L from one outermost terminal 9 of the connection terminal 6 of the tape carrier 5 to the other outermost terminal 10.
Was measured in advance, and the same portion was measured after hot pressing, and the difference was defined as the amount of elongation of the tape carrier 5. The result is
It is shown in (Table 4).

[0024]

[Table 4]

As can be seen from Tables 2 and 3, and FIGS. 3, 4 and 5, the temperature changes tend to be the same for samples 1, 2 and 3, and the lowering speed of the bonding tool 7 Although the temperature rise does not change even if the speed is increased as described above, the tendency of the pressure change is different between Samples 1, 2 and 3, and Sample 3 in which the bonding tool 7 descends at a high speed.
In the case, the pressure rises faster. According to Table 4, the descending speed of the bonding tool 7 is set at 8.
It can be seen that the elongation of the tape carrier 5 is the smallest at 45.3 (39 to 50) (μm) in Sample 3, which was the fastest at 0 cm / sec. This is because the rise of the pressure applied to the anisotropic conductive adhesive sheet 3 is increased so that the heat applied to the tape carrier 5 causes the anisotropic conductive adhesive sheet 3 to be close to the ultimate pressure before the tape carrier 5 expands. This is because the pressure can be increased. In addition, this can be seen from the conditions of the thermal pressurization (Table 2),
As can be seen from Table 3 and FIG. 5, which is a time-temperature / pressure change diagram of Sample 3, anisotropic conductive adhesive sheet 3
Can be achieved when the pressure applied to the anisotropic conductive adhesive sheet 3 is 80% to 85% of the final ultimate pressure when the temperature applied to the final reaches 85% of the final ultimate temperature.

In the above embodiment, the connection terminal 6 of the tape carrier 5 and the Al electrode 2 of the liquid crystal display panel 1 are opposed to each other, and the bonding tool of a constant heating method is applied via the anisotropic conductive adhesive sheet 3. Although the case of connection has been described, the present invention is not limited to the liquid crystal display panel 1 but can be applied to connection between a semiconductor element and a printed circuit board.

[0027]

According to the tape carrier connecting method of the present invention, the anisotropic conductive adhesive interposed between the tape carrier and the electronic device substrate in the step of connecting the tape carrier to the electronic device substrate such as a liquid crystal display panel. By speeding up the rise of the pressure applied to the agent sheet, the amount of elongation of the tape carrier can be suppressed, and the alignment accuracy between the electrode of the electronic device substrate and the connection terminal of the tape carrier is improved.
Further, even when the connection terminals of the tape carrier have a narrow pitch, high yield and high reliability can be secured.

[Brief description of the drawings]

FIG. 1 is a sectional view of a tape carrier connecting method according to an embodiment of the present invention before a thermal press in a connecting process between a tape carrier and a liquid crystal display panel.

FIG. 2 is a cross-sectional view of the tape carrier connecting method according to an embodiment of the present invention when the tape carrier is connected to a liquid crystal display panel by applying heat and pressure;

FIG. 3 is a time-temperature / pressure change diagram of a sample 1 in the embodiment of the method for connecting a tape carrier according to the present invention.

FIG. 4 is a time-temperature / pressure change diagram of a sample 2 in the embodiment of the method for connecting a tape carrier according to the present invention.

FIG. 5 is a time-temperature / pressure change diagram of a sample 3 in the embodiment of the method for connecting a tape carrier according to the present invention.

FIG. 6 is a sectional view of a tape carrier.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Liquid crystal display panel 2 Al electrode 3 Anisotropic conductive adhesive sheet 4 Conductive particle 5 Tape carrier 6 Connection terminal 7 Bonding tool 8 Teflon sheet

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Tatsufumi Ogata 1006 Kazuma Kadoma, Kadoma City, Osaka Inside Matsushita Electric Industrial Co., Ltd.

Claims (2)

[Claims] 1. An anisotropic conductive adhesive is applied when a connection terminal of a tape carrier and an electrode of an electronic device substrate are opposed to each other via an anisotropic conductive adhesive sheet, and the tape carrier is heat-pressed from the upper surface by a bonding tool. When the temperature applied to the adhesive sheet reaches 85% of the ultimate temperature, the pressure applied to the anisotropic conductive adhesive sheet is 80% or more and 85% of the ultimate pressure.
A method of connecting a tape carrier to be heated and pressed as described below. 2. The method of connecting a tape carrier according to claim 1, wherein the method of applying heat and pressure from the upper surface of the tape carrier with a bonding tool is a constant heating method.