JP3326339B2 - Method for manufacturing flat display device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a connecting device for thermocompression bonding circuit boards and a method for manufacturing a flat display device such as a liquid crystal display device using the connecting device.

[0002]

2. Description of the Related Art A method of manufacturing a conventional flat display device will be described using a TFT (thin film transistor) type liquid crystal display device. FIG. 6 shows a plan view of a conventional TFT liquid crystal display device. First, the active matrix substrate 5 is formed on a substrate such as glass so that the source lines 2 intersect with the gate lines 1 and a gate insulating film (not shown) therebetween. The gate wiring 1 is connected to an external circuit board connection terminal (hereinafter referred to as a mounting terminal) 3, and the source wiring 2 is connected to a mounting terminal 4, and a signal is input from the outside. At this time, the mounting terminals are also formed at the same time when each wiring is formed. Then, pixel electrodes (not shown) are formed in a matrix, and TFTs (not shown) serving as switching elements are provided near these pixel electrodes.
Is arranged. Then, the active matrix substrate 5 and the opposing substrate 6 provided with an opposing electrode and the like are attached to each other, the gap is made constant by the spacer, and the liquid crystal is sealed with the sealant 11 to form a liquid crystal panel.

After the completion of the liquid crystal panel, the liquid crystal panel is inspected as shown in the flowchart of FIG. 8, and only non-defective products are sent to the next polarizing plate attaching step. Thereafter, an ACF (anisotropic conductive film) is attached to at least the mounting terminals in the mounting area. And the TCP punched out of the tape in a separate process
Is attached to the above-mentioned ACF to perform alignment. After that, the TCP and the panel are temporarily connected. Hereinafter, the temporary connection step will be described with reference to FIGS.

In FIGS. 9 (a) and 9 (b), a support 25
The connection base 15 is arranged via the upper support member 24. Further, a bonding head 21 and a bonding tool (a hatched portion at the tip of the bonding head) are formed via a support 26 fixed to the support table, a pressing cylinder 23 and a pressing rod 22, and a wiring (not shown) is provided on the bonding tool. Then, the liquid crystal panel and the TCP 7 are thermocompression-bonded by raising and lowering the bonding tool. Incidentally, the bonding head 21 and the bonding tool are usually formed integrally. Hereinafter, in the description of the partial cross-sectional views, only the bonding tool is illustrated.

FIGS. 10 (a) and 10 (b) are partially enlarged sectional views showing a temporary connection step. In FIG. 10, a liquid crystal panel in which an active matrix substrate 5 provided with mounting terminals 3 and 4 and a counter substrate 6 are sealed with a liquid crystal therebetween using a sealing material 11 and bonded together is mounted on a connection base 15. .
Note that, in the drawings, wiring and the like in the sealant 11 are not shown. An ACF 10 in which conductive particles are mixed in an insulating resin is attached to the mounting terminal 4 and its peripheral region, and a TCP 7 is positioned and arranged thereon. Then, the bonding tool 20 is lowered as indicated by the arrow, and the TCP 7 is pressed at a pressure of 10 kg / cm ² at, for example, 100 ° C. for 3 seconds, and thermocompression bonding is performed to perform temporary connection. As a result, the TCP 7 and the terminal 4 of the liquid crystal panel are temporarily connected. After that, longer time at higher temperature than the temporary connection process,
For example, main connection is performed by thermocompression bonding at a pressure of 30 kg / cm ² at 200 ° C. for 20 seconds. Since the temporary connection and the main connection have completely different connection conditions, they are generally performed using different devices.

As described above, the connection in two stages can be performed at a lower temperature than the solder connection when the ACF 10 is fixed. However, when the thermosetting system is used as the insulating resin for bonding, 170 to 190 is used. This is because, even in the case of a thermoplastic resin, a curing temperature of about 130 to 170 degrees is required as a curing temperature, so that the base material of the TCP 7 elongates or shifts during connection, and connection failure is likely to occur. Further, the connection time in a high temperature state can be shortened.

Thereafter, a TCP connection test is performed, and a printed circuit board (hereinafter, referred to as PWB) on which a display circuit is mounted is mounted on a TC board.
A final inspection is performed through a module assembling step of connecting to P and incorporating a backlight and the like, and a liquid crystal display device is completed.

[0008]

The display itself can be performed even in the provisionally connected state, and there is no deviation or deviation with a slight vibration. However, when a strong impact is applied in a car or the like, the sheet shifts or peels off, resulting in poor display. In addition, in the temporary connection state, since the curing reaction of the resin is insufficient, the connection reliability deteriorates with time, and display failure occurs. For this reason, it is not permissible to send at least one temporarily connected liquid crystal display device to the market.

However, there is a possibility that a device that controls the line may fail or malfunction due to a lightning strike or the like, and a liquid crystal panel that has not been permanently connected may be sent to a subsequent process due to an operator error. is there. This is because if the TCP and the liquid crystal panel are just aligned, a defect is found in the TCP connection inspection process and is not sent to the subsequent processes, but as shown by the dotted line in FIG. After the TCP and the liquid crystal panel are temporarily connected, it is temporarily fixed.
And the liquid crystal panel are connected to each other, and are electrically connected. Therefore, even if a lighting test is performed, the liquid crystal panel becomes a non-defective product and may be sent to a subsequent process.

It is an object of the present invention to provide a method for manufacturing equipment which may malfunction due to a natural disaster or a human error.
An object of the present invention is to manufacture a flat-panel display device by a manufacturing method that does not allow defective connection products to flow to a subsequent process.

[0011]

The flat display device according to the present invention.
Is a method of manufacturing a display medium such as a liquid crystal between substrates facing each other.
Minimize the display panel that encapsulates the body and the external circuit board
The display panel and the external circuit board are also provided with an anisotropic conductive film.
When connecting with a flat type
In the method of manufacturing a display device, the bonding
A notch is provided in at least a part of the
The notch of the binding tool is
And at least two connection terminals and the connection area of the circuit board
Using a thermo-compression type connection device that is 50% or less of
The continuation is at a higher temperature and a longer time with stronger pressure than the temporary connection process.
It is characterized by thermocompression bonding .

[0012]

[0013]

[0014]

By using this manufacturing method, even if a malfunction of the manufacturing apparatus due to a natural disaster or the like occurs, it is immediately known whether or not the connection is in a temporary connection state. Disappears.

The notch of the bonding tool
Is at least two connection terminals of the circuit board,
It may be 50% or less of the connection area of the circuit board.
By using this manufacturing method, misalignment hardly occurs at the time of main connection. Further, when a flexible circuit board such as TCP is used as the external circuit board, the extension of the base material can be reduced, and the connection failure can be reduced. In addition, it is possible to easily distinguish a defective connection after the actual connection.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention
A T-type liquid crystal display device will be described as an example with reference to the drawings.
The same parts as those in the related art are denoted by the same reference numerals, and the description will be simplified.

Embodiment 1 FIG. 6 is a plan view of a TFT type liquid crystal display device. In FIG. 6, first, the active matrix substrate 5 is made of aluminum,
The gate wiring 1 is formed of tantalum or the like, and the source wirings 2 are formed of aluminum, tantalum or the like so as to intersect each other with a gate insulating film (not shown) formed of silicon nitride or the like interposed therebetween. Then, pixel electrodes (not shown) are formed in a matrix form using ITO, aluminum, or the like. A TFT (not shown) connected to the gate line 1, the source line 2, and the pixel electrode is arranged near each pixel electrode. At this time, the mounting terminals 3 and 4 are also formed at the same time when each wiring is formed. These are formed by forming a conductive film or an insulating film and then patterning the film by a photolithography process and an etching process. Then, the active matrix substrate 5 is bonded to a counter substrate 6 provided with a counter electrode (not shown), a gap is made constant with a spacer (not shown), and a liquid crystal (not shown) is sealed with a sealant to form a liquid crystal panel.

After the completion of the liquid crystal panel, the liquid crystal panel is inspected as shown in the flowchart of FIG.
Only non-defective products are sent to the next polarizing plate sticking process. After that, the ACF is attached to at least the mounting terminals in the mounting area. Then, the TCP punched out of the tape in a separate step is attached to the ACF to perform alignment. After that, the TCP and the liquid crystal panel are temporarily connected. Here, the ACF is attached to the liquid crystal panel side, but may be attached to the TCP side. Hereinafter, the temporary connection step will be described with reference to FIGS.

9 (a) and 9 (b), the support 25
The connection base 15 is arranged via the upper support member 24. Further, a bonding head 21 and a bonding tool (a hatched portion at the tip of the bonding head) are formed via a support 26 fixed to the support table, a pressing cylinder 23 and a pressing rod 22, and a wiring (not shown) is provided on the bonding tool. Then, the liquid crystal panel and the TCP 7 are thermocompression-bonded by raising and lowering the bonding tool. In addition, invar (an alloy mainly composed of about 64% of iron and about 36% of nickel) and super amber (an alloy mainly composed of about 64% of iron, about 32% of nickel and about 4% of cobalt) Thus, the bonding head 21 and the bonding tool are usually formed integrally.

FIGS. 1A and 1B are partially enlarged views of FIG. 9, and are AA 'sectional view and BB' sectional view of FIG. 7, respectively. In FIG. 1, a liquid crystal panel in which an active matrix substrate 5 having mounting terminals 3 and 4 and a counter substrate 6 are bonded to each other through a liquid crystal using a sealant 11 is mounted on a connection base 15. In the drawings, the source wiring and the like in the seal are not shown. An ACF 10 in which conductive particles are mixed in an insulating resin is attached to the mounting terminal 4 and its peripheral region, and a TCP 7 is positioned and arranged thereon. Then, the bonding tool 14 is moved in the direction of the arrow, and the TCP 7 is pressed at a pressure of 10 kg / cm ² at 100 ° C. for 3 seconds, for example, and thermally connected to perform temporary connection. At this time, a cushion rubber or the like may be interposed therebetween.

The bonding tool 14 of this embodiment is
As shown in FIG. 1B, a notch corresponding to the center of each TCP 7 is provided. Therefore, since the central part is not connected, even if it is sent to the post process for some reason, a connection failure is found in the inspection process,
It does not flow to subsequent steps. At this time, the size of the notch may be one or more wires separately, but if it is one, it is indistinguishable from a normal connection failure at the time of real connection, and the processing of the bonding tool 14 Although it depends on the size of the TCP 7 due to a problem of accuracy or the like, it is preferable that the length is two mm or more and about several mm to 1 cm. In addition, if the area that is not so connected is increased, a positional shift is likely to occur at the time of the actual connection.
It is desirable to make the following.

Here, the notch is provided at a position corresponding to the center of the TCP 7 of the bonding tool 14, but as shown in FIG. 5A, the center is connected and the end is not connected. May be. Further, as shown in FIG. 5B, a plurality of notches may be provided for one TCP 7. According to this structure, a connection failure is confirmed at a plurality of places, and it is easily understood that the connection is temporary.

Thus, the TCP 7 and the terminal 4 of the liquid crystal panel are temporarily connected. Thereafter, a higher pressure at a higher temperature and a longer time than the temporary connection step, for example, 30 seconds at 170 degrees for 20 seconds.
The main connection for thermocompression bonding is performed at a pressure of kg / cm ² .

Then, T shown in the flowchart of FIG.
A CP connection check is performed. In this inspection process, the liquid crystal panel, T
An abnormality of the CP, a connection failure between the liquid crystal panel and the TCP, and the like are inspected. At this time, even if a liquid crystal display device that is only temporarily connected is sent, the terminal corresponding to the notch portion is floating without being connected, or even if the liquid crystal display device is temporarily connected, another terminal is not connected. Since the connection is weaker than the portion and the connection resistance is higher, an abnormal display is caused, and the lighting inspection can be easily performed. The inspection can also be performed by examining the trace of the bonding tool 20 at the connection portion of the TCP 7.

Thereafter, the PWB on which the display circuit is mounted is
A final inspection is performed through a module assembling process for connecting to a CP and incorporating a backlight and the like, and a liquid crystal display device is completed.

As described above, according to the manufacturing method of the liquid crystal display device of the present embodiment, even if something temporarily connected only flows as shown by a dotted line in FIG. It is discovered by inspection and does not flow to subsequent processes.

(Embodiment 2) FIG. 2 is a view showing a temporary connection step according to Embodiment 2 of the present invention, and is a cross-sectional view taken along the line BB 'of FIG. Note that the steps other than the temporary connection step are the same as those in the first embodiment, and a description thereof will not be repeated.

In this embodiment, the bonding tool 14
Is provided only in one of the three TCPs 7 here, and the remaining two are provisionally connected in the entire area. Even in this case, it is desirable that both ends of the connection region of the TCP 7 corresponding to the cutout portion are connected, and the area of the cutout portion is desirably 50% or less of the total connection area. Even when the temporary connection bonding tool 14 is used, a connection failure is found in the inspection process as in the first embodiment, and does not flow to a subsequent process.

(Embodiment 3) FIG. 3 is a view showing a temporary connection step according to Embodiment 3 of the present invention, and is a cross-sectional view taken along the line BB 'of FIG. Note that the steps other than the temporary connection step are the same as those in the first embodiment, and a description thereof will not be repeated.

In this embodiment, the temporary connection is performed by using a plurality of bonding tools 14 each having a notch. Even in this case, it is desirable that both ends of the connection region of the TCP 7 corresponding to the cutout portion are connected, and the area of the cutout portion is desirably 50% or less of the total connection area.

In this embodiment, one bonding tool 14 is used for each of the plurality of TCPs 7. However, the bonding tool 14 may be divided into two or more, or a plurality of TCPs 7 may be temporarily connected by one bonding tool 14. . Further, it is not necessary to provide notches in all of the plurality of bonding tools 14, but it is sufficient to provide them in any one of them. Even when the bonding tool 14 is used, a connection failure is found in the inspection process as in the first embodiment, and does not flow to a subsequent process.

(Embodiment 4) FIG. 4 is a diagram showing a temporary connection step according to Embodiment 4 of the present invention. In this embodiment, a COG (chip-on-glass) system in which a driving IC as an external circuit board is directly connected to the board is used. Also,
Except for the temporary connection step, the process is the same as that of the first embodiment, and a description thereof will be omitted.

First, similarly to the first embodiment, the ACF 10 is attached to at least the mounting terminals 4 in the mounting area.
Then, the bumps 9 of the chip 8 and the mounting terminals 4 on the panel are attached to the ACF to perform alignment. Here, the ACF 10 is attached to the liquid crystal panel side, but may be attached to the chip 8 side.

Then, the temporary connection is performed by the bonding tool 14 having a cutout portion provided in a portion corresponding to each chip 8. Even in this case, a notch corresponding to the central portion of the chip 8 is provided. Therefore, since the central portion is not connected, even if the central portion is sent to a subsequent process for some reason, a connection failure is found in the inspection process and does not flow to the subsequent processes. At this time, the size of the cutout portion is several mm to several cm depending on the size of the chip 8 because the chip 8 is harder than a flexible substrate such as TCP, so that the chip 8 is connected unless formed larger. It is. In addition, if the area that is not so connected is increased, misalignment is likely to occur at the time of the actual connection. Therefore, it is preferable that the connection area of each chip 8 be 50% or less.

As described above, the present invention can be applied to the COG method. In this case, as in the first embodiment, a connection failure is found in the inspection process and does not flow to the subsequent processes. Also,
It can be determined by examining the melting state of the resin of the ACF. Note that the bonding tool 14 according to the second and third embodiments can be used even when the connection is performed using the COG method as in the present embodiment.

Although the embodiments of the present invention have been described with reference to the TFT type liquid crystal display device as an example, a simple matrix type liquid crystal display device, EL (electroluminescence),
Other display devices such as plasma can also be used.

[0038]

According to the method of manufacturing a flat display device of the present invention.
Then, a display medium such as a liquid crystal is sealed between the substrates arranged opposite to each other.
Display panel, and at least an external circuit board,
The display panel and the external circuit board are connected by an anisotropic conductive film.
When connecting the flat display device through the temporary connection process
In the manufacturing method of the above, the temporary connection, the external circuit board
By temporarily not connecting some parts, the product
Even if erroneous operation of the manufacturing equipment
It is easy to determine whether the connection is defective.
It will not be sent enough.

[0039]

[0040]

The notch of the bonding tool
Is at least two connection terminals of the circuit board,
It may be 50% or less of the connection area of the circuit board.
Further, when a flexible circuit board such as TCP is used as the external circuit board, the extension of the base material can be reduced, and the connection failure can be reduced. In addition, it is possible to easily distinguish a defective connection after the actual connection.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a TF during a temporary connection step according to a first embodiment of the present invention.
It is sectional drawing of a T-type liquid crystal display device.

FIG. 2 is a diagram illustrating a TF during a temporary connection step according to a second embodiment of the present invention.
It is sectional drawing of a T-type liquid crystal display device.

FIG. 3 is a diagram illustrating a TF during a temporary connection step according to a third embodiment of the present invention.
It is sectional drawing of a T-type liquid crystal display device.

FIG. 4 is a diagram illustrating a TF during a temporary connection step according to a fourth embodiment of the present invention.
It is sectional drawing of a T-type liquid crystal display device.

FIG. 5 shows another bonding tool according to the first embodiment of the present invention.

FIG. 6 is a plan view of the TFT type liquid crystal display device before connection to an external circuit board.

FIG. 7 shows an external circuit board (TC) of a TFT type liquid crystal display device.
P) is a plan view after connection.

FIG. 8 is a flowchart of a mounting process of the TFT type liquid crystal display device.

FIG. 9 is an overall view of a temporary connection device.

FIG. 10 is a cross-sectional view of a TFT type liquid crystal display device during a conventional temporary connection step.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Gate wiring 2 Source wiring 5 Active matrix substrate 6 Counter substrate 7 TCP (tape carrier package) 8 Chip 10 ACF (anisotropic conductive film) 11 Sealant 14 Bonding tool 15 Connection stand

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G02F 1/1345 H01L 21/60

Claims (1)

(57) [Claims] 1. A display medium such as a liquid crystal between substrates opposed to each other.
Minimize the display panel that encapsulates the body and the external circuit board
The display panel and the external circuit board are also provided with an anisotropic conductive film.
When connecting with a flat type
In the method of manufacturing a display device, at the time of the temporary connection, at least a part of the bonding tool
A notch is provided, and the notch of the bonding tool is provided.
Is at least two connection terminals of the circuit board,
A thermocompression-type connection that is 50% or less of the connection area of the circuit board.
Connection device, and this connection is performed at a higher temperature and for a longer time than the temporary connection process.
Thermo-compression bonding at a low pressure.
Production method.