JP2000181369A - Display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a COG(chip-on-glass) type liquid crystal display device which does not decrease in the number of obtained glass substrates while maintaining high connection reliability and has small external shape. SOLUTION: This display device has a through hole 17 penetrating a monolithic semiconductor integrated circuit 2, a wiring substrate connection electrode 8 connected to the monolithic semiconductor integrated circuit 2 through the through hole on the opposite surface from the circuit formation surface 20 of the monolithic semiconductor integrated circuit 2, and a wiring substrate electrode 10, formed on a wiring substrate 2, connected to the wiring substrate connection electrode 8, and is supplied with signals inputted to the monolithic semiconductor integrated circuit 2 or the electric power from the wiring substrate 3. Thus, the wiring substrate connection electrode 8 is formed on the monolithic semiconductor integrated circuit 2, so the space for connecting the wiring substrate 3 to the display panel is not necessary and then a non-display area 4b of the display panel 1 becomes small correspondingly.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a display device such as a liquid crystal display device and a plasma display device.

[0002]

2. Description of the Related Art Conventional display devices include, for example, a liquid crystal display device and a plasma display device.

Here, a liquid crystal display device will be described as a specific example as a conventional display device. The liquid crystal display device is C
Compared to displays such as RT (Cathode Ray Tube), it has excellent features such as low power and light weight, and its product power has been enhanced by advances in peripheral technology, and it has been used in various products. In particular, in an active matrix type liquid crystal display device using a thin film transistor (hereinafter referred to as a TFT) as a switching element for each pixel in a display area, a clear image display without crosstalk can be obtained. It is widely used in the field of car navigation displays.

In general, in a liquid crystal display device, it is necessary to form a drive circuit for operating each pixel in a display area of a liquid crystal display panel in a non-display area. As one of the methods, there is a method of directly mounting an IC chip or the like on which a drive circuit is formed on a glass substrate constituting a liquid crystal display panel. Since this method is compact and has improved vibration resistance, the portability, which is a characteristic of the liquid crystal display device, is further increased, and this forming method is becoming mainstream. In this connection method, since an IC chip is directly mounted on a glass substrate, COG (Chip)
On Glass) method.

Here, a liquid crystal display device in which a driving circuit is formed by the COG method will be specifically described as an example.

[0006] As shown in FIG.
The liquid crystal display panel 1 and a monolithic semiconductor integrated circuit
It is composed of a C chip 2 and a wiring board 3.

The IC chip 2 includes a TFT (not shown) formed in each pixel of the display area 4a of the liquid crystal display panel 1.
To drive each pixel, and is mounted on the non-display area 4b by COG. Note that this IC chip 2
Includes a signal line IC chip 2a and a scanning line IC chip 2a.
b.

As shown in FIG. 5, an output terminal (not shown) of the IC chip 2 is connected to an output electrode 6 on a wiring extending from each TFT in the display area 4a to the non-display area 4b, and is connected to an input terminal of the IC chip 2. Terminals (not shown) are connected to the input electrodes 7 formed in the non-display area 4b so that the IC
The chip 2 is mounted by COG.

The wiring board connection electrode 8 is connected to the input electrode 7 on the liquid crystal display panel, and is used to face and connect to the wiring board electrode 10 formed on the wiring board 3.

The wiring board 3 includes a wiring board electrode 10 formed to be connected to a wiring board connecting electrode 8 formed in the non-display area 4b so as to supply various signals and power to the IC chip 2. A plurality of common wirings 11 for supplying signals to the IC chip 2 are formed, and are configured with a common wiring forming section 12 having a multilayer structure.

The wiring board 3 is formed of a material such as a polyimide film so that it can be bent.
Thus, after the wiring board 3 is connected to the liquid crystal display panel 1, it is bent toward the liquid crystal display panel 1 to reduce the size from the front of the screen of the liquid crystal display device, thereby maintaining the compactness characteristic of the COG method. I'm sorry.

The wiring board 3 has a power supply to the IC chip 2,
Wirings for a reference voltage, various transfer clocks, control signals, and the like are formed.

FIG. 6 shows a display area 4a of the liquid crystal display panel 1.
Another method for forming a drive circuit for operating a TFT (not shown) formed in each pixel in the non-display area 4b is shown, wherein the IC chip 2 on which the drive circuit is formed is shown.
Is mounted on a film substrate 13 formed of a material such as a polyimide film, and then connected to a film substrate connection electrode 14 formed on the liquid crystal display panel 1. This method is generally used for TCP (Tape Carrier Pacage).
It is called a method.

[0014]

However, the above-mentioned conventional display device has the following problems. That is, as compared with the COG method and the TCP method, the film substrate connection electrode 14 may be formed in the non-display area 4b in the TCP method, but the IC chip 2 and the wiring board connection electrode 8 are formed in the non-display area 4b in the COG method. Is necessary, and the size of the glass substrate becomes large only for the IC chip 2. Therefore, COG
In the method, there are problems that the number of glass substrates to be removed is reduced and that the external dimensions of the liquid crystal display device from the front of the screen are increased.

On the other hand, the TCP system has a larger number of connection points than the COG system, and has problems such as a reduction in manufacturing yield, and a reduction in reliability because the film substrate is easily broken by vibration or impact. In the case of a display device such as a plasma display device other than the liquid crystal display device, the same configuration is used, and there is a similar problem as described above.

Accordingly, it is an object of the present invention to reduce the number of glass substrates to be obtained while maintaining high connection reliability.
Another object of the present invention is to provide a COG liquid crystal display device having a small external dimension.

[0017]

According to a first aspect of the present invention, there is provided a display device, comprising: an electrode formed on a display panel; and a display operation of the display panel. A display device comprising a wiring board for connecting a projecting electrode formed on a circuit forming surface in a monolithic semiconductor integrated circuit and supplying a driving voltage to the monolithic semiconductor integrated circuit, wherein the through-hole penetrates through the monolithic semiconductor integrated circuit. A hole is formed, and a wiring board connection electrode connected to the monolithic semiconductor integrated circuit via a through hole is formed on the surface opposite to the circuit formation surface of the monolithic semiconductor integrated circuit, and the wiring board connection electrode is formed on the wiring board. Connecting the formed wiring board electrodes and supplying a signal or power input to the monolithic semiconductor integrated circuit from the wiring board. That.

As described above, the through-hole penetrating through the monolithic semiconductor integrated circuit is formed, and the wiring board connected to the monolithic semiconductor integrated circuit via the through-hole on the surface opposite to the circuit forming surface of the monolithic semiconductor integrated circuit. A connection electrode is formed, a wiring board electrode formed on the wiring board is connected to the wiring board connection electrode, and a signal or power input to the monolithic semiconductor integrated circuit is supplied from the wiring board. Is formed on the monolithic semiconductor integrated circuit, so that a space for connecting the wiring board to the display panel is not required, and the non-display area of the display panel can be reduced accordingly. For this reason, without reducing the number of glass substrates, CO
A liquid crystal display device using the G method can be provided. Further, since a film substrate is not used as in the conventional example, the number of connection points is increased, and problems such as breakage of the film substrate can be solved, thereby improving reliability.

The liquid crystal display device according to the second aspect is the first aspect.
, A display panel and a monolithic semiconductor integrated circuit,
The connection between the monolithic semiconductor integrated circuit and the wiring board is connected by an adhesive made of an organic resin, and the glass transition temperature of the organic resin used for connecting the display panel and the monolithic semiconductor integrated circuit is the same as that of the monolithic semiconductor integrated circuit. Higher than the connection temperature with the wiring board.

In the above configuration, the connection between the display panel and the monolithic semiconductor integrated circuit requires a finer electrode pitch and parallelism of the members is required. Are connected, and then the monolithic semiconductor integrated circuit and the wiring board are connected. Therefore, before connecting the wiring substrate and the monolithic semiconductor integrated circuit, the monolithic semiconductor integrated circuit is already connected to the liquid crystal display panel, so that the display panel and the monolithic semiconductor integrated circuit are connected at the temperature at which the wiring substrate is connected. It is necessary to prevent the anisotropic conductive adhesive from being damaged. Therefore, as described above,
The connection between the display panel and the monolithic semiconductor integrated circuit, and the connection between the monolithic semiconductor integrated circuit and the wiring board are connected with an adhesive made of an organic resin, and the glass transition of the organic resin used for the connection between the display panel and the monolithic semiconductor integrated circuit. Since the temperature is higher than the connection temperature between the monolithic semiconductor integrated circuit and the wiring board, the connection between the display panel and the monolithic semiconductor integrated circuit is not affected when the wiring board is connected. Thus, a high-quality display device can be obtained while maintaining high connection reliability.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS. Here, a liquid crystal display device as a display device will be described as an example.

FIG. 1 is a partial sectional view of a liquid crystal display device according to an embodiment of the present invention, FIG. 2 is a plan view thereof, and FIG. 3 is a partially enlarged perspective view thereof. As shown in FIG. 2, this liquid crystal display device includes a liquid crystal display panel 1, an IC chip 2 such as a monolithic semiconductor integrated circuit, and a wiring board 3. In addition, the wiring board 3 has a configuration in which the electrodes 6 formed on the liquid crystal display panel 1 and the protruding electrodes 5 formed on the circuit forming surface 20 in the IC chip 2 for performing the display operation of the liquid crystal display panel 1 are connected. Supplies a driving voltage such as a signal and a power supply to the IC chip 2.

In the non-display area 4b of the liquid crystal display panel 1,
As shown in FIG. 1, the output terminal of the IC chip 2 is connected to a TFT (not shown) formed in each pixel of the display area 4a of the liquid crystal display panel 1 and is connected to a wiring drawn to the non-display area 4b. An output electrode 6 is formed so as to face and connect to the protruding electrode 5. The IC chip 2 controls a TFT (not shown) formed in each pixel of the display area 4a of the liquid crystal display panel 1 to drive each pixel to cause the liquid crystal display panel 1 to perform a display operation. COG is mounted on the display area 4b. The IC chip 2 includes a signal line IC chip 2a and a scanning line IC chip 2b (FIG. 2).

The output terminal 5 and the output electrode 6 are formed on the side of the non-display area 4b near the display area 4a. A dummy terminal 9 is formed on the side of the IC chip 2 on the side opposite to the output terminal 5 to balance when connecting the IC chip 2.
Also, a dummy electrode 16 is formed on the liquid crystal display panel.
The output electrode 6 and the dummy electrode 16 formed in the non-display area 4b are formed simultaneously with the TFT by diverting the conductive thin film used for forming the TFT in the display area 4a.

The IC chip 2 has a through hole 17 penetrating therethrough. Further, a wiring board connection electrode 8 for inputting a power supply or a transfer clock to a circuit of the IC chip 2 is formed on a surface of the IC chip 2 opposite to the circuit forming surface 20. The wiring board connection electrode 8 is connected to a circuit of the IC chip 2 through a through hole 17 penetrating the IC chip 2. In these forming methods, after a semiconductor integrated circuit is formed on the IC chip 2, an input portion to the circuit is etched.
A vertical hole is made in the IC chip 2. Next, gold plating is applied to the vertical hole to make the wall surface of the vertical hole conductive. Thereafter, wrapping processing is performed from the back surface until the vertical holes are exposed. Then, the through holes 17 are formed by performing gold plating on the vertical holes.
When the through holes 17 are formed by plating, the wiring board connection electrodes 8 are also formed. In this embodiment, the through hole 1
The hole diameter of No. 7 was 40 μm, and the LSI thickness was 130 μm.
Gallium arsenide was used as the material of the IC chip 2.

The wiring board 3 connects the wiring board electrode 10 to the wiring board connection electrode 8 to supply a signal or power input to the IC chip 2. In this case, the wiring board 3
Is made of a base material using a bendable material such as a polyimide film, and the portion where the wiring board electrode 10 is formed has a single-layer shape of the polyimide film. Also, as shown in FIG. 3, the wiring board electrode 10 is branched from the common wiring 11 for each signal (power supply, transfer clock, etc.). Multi-layer. In this embodiment, a 25-μm-thick polyimide film is used for the formation portion of the wiring board electrode 10 to improve the bendability after connection.

The liquid crystal display panel 1 and the IC chip 2 and the wiring board 3 and the IC chip 2 are made of an anisotropic conductive adhesive (ACF: Anisotoropic) in which conductive particles obtained by applying gold plating to resin balls are dispersed in an organic resin. Connect via Conductive Film).

The order of connection is as follows.
The C chip 2 is connected, and then the wiring board 3 and the IC chip 2 are connected. This is because the connection between the liquid crystal display panel 1 and the IC chip 2 requires a finer electrode pitch and requires parallelism between members.

At this time, the liquid crystal display panel 1 and the IC chip 2
Anisotropic conductive adhesive 18 used for connection and the anisotropic conductive adhesive 19 for connecting the wiring board 3 and the IC chip 2 have different connection temperatures and glass transition temperatures of the thermosetting resin at the time of connection. Is used. In this embodiment, a thermosetting resin such as an epoxy resin is used as the organic resin, and the glass transition temperature of the thermosetting epoxy resin used for the liquid crystal display panel 1 and the IC chip 2 is determined by connecting the wiring board 3 and the IC chip 2. An anisotropic conductive adhesive is used which is higher than the temperature at which the heat treatment is performed. This means that before connecting the wiring board 3 and the IC chip 2, the IC
Since the chip 2 is already connected to the liquid crystal display panel 1, the liquid crystal display panel 1 is connected at the temperature at which the wiring board 3 is connected.
This is to prevent the anisotropic conductive adhesive 18 connecting the IC chip 2 from being damaged. Specifically, the liquid crystal display panel 1 is connected to the IC chip 2 using an anisotropic conductive adhesive having a glass transition temperature of 137 ° C. of the thermosetting epoxy resin. Used an anisotropic conductive adhesive having a connection temperature of 110 ° C.

As described above, according to this embodiment, I
IC chip 2 on the surface opposite to circuit forming surface 20 of C chip 2
The wiring board electrode 8 for inputting a power supply and a transfer clock to the circuit is formed, and the wiring board connection electrode 10 formed on the wiring board 3 is connected to the wiring board electrode 8. A space for connecting the wiring board connection electrode 10 to the non-display area 4b is not required, and a compact liquid crystal display device can be obtained without reducing the number of glass substrates to be taken.

The glass transition temperature of the organic resin of the anisotropic conductive adhesive 18 used for the liquid crystal display panel 1 and the IC chip 2 is higher than the temperature at which the wiring board 3 and the IC chip 2 are connected. The organic resin connecting the liquid crystal display panel 1 and the IC chip 2 is not damaged at the temperature at which the substrate 3 is connected, and a high quality liquid crystal display device can be obtained.

In this embodiment, the case of a liquid crystal display device has been described. However, similar effects can be obtained in the case of a display device other than a liquid crystal display device such as a plasma display device.

[0033]

According to the display device of the present invention, a through-hole penetrating the inside of the monolithic semiconductor integrated circuit is formed, and the monolithic semiconductor integrated circuit is formed on the surface opposite to the circuit forming surface of the monolithic semiconductor integrated circuit via the through-hole. Form a wiring board connection electrode connected to the circuit, connect the wiring board electrode formed on the wiring board to this wiring board connection electrode, and supply a signal or power input to the monolithic semiconductor integrated circuit from the wiring board Therefore, the wiring board connection electrode is formed on the monolithic semiconductor integrated circuit, and the space for connecting the wiring board to the display panel becomes unnecessary.
The non-display area of the display panel can be reduced accordingly. Therefore, without reducing the number of glass substrates,
A liquid crystal display device using a COG method with small external dimensions can be provided. Further, since a film substrate is not used as in the conventional example, the number of connection points is increased, and problems such as breakage of the film substrate can be solved, thereby improving reliability.

According to the second aspect of the present invention, in the above configuration, the connection between the display panel and the monolithic semiconductor integrated circuit requires a finer electrode pitch and parallelism of the members is required. And the monolithic semiconductor integrated circuit, and then the monolithic semiconductor integrated circuit and the wiring board. Therefore, before connecting the wiring substrate and the monolithic semiconductor integrated circuit, the monolithic semiconductor integrated circuit is already connected to the liquid crystal display panel, so that the display panel and the monolithic semiconductor integrated circuit are connected at the temperature at which the wiring substrate is connected. It is necessary to prevent the anisotropic conductive adhesive from being damaged. For this reason,
The connection between the display panel and the monolithic semiconductor integrated circuit, and the connection between the monolithic semiconductor integrated circuit and the wiring board are connected with an adhesive made of an organic resin, and the glass transition of the organic resin used for the connection between the display panel and the monolithic semiconductor integrated circuit. Since the temperature is higher than the connection temperature between the monolithic semiconductor integrated circuit and the wiring board, the connection between the display panel and the monolithic semiconductor integrated circuit is not affected when the wiring board is connected. Thus, a high-quality display device can be obtained while maintaining high connection reliability.

[Brief description of the drawings]

FIG. 1 is a partial sectional view of a liquid crystal display device according to an embodiment of the present invention.

FIG. 2 is a plan view of the liquid crystal display device according to the embodiment of the present invention.

FIG. 3 is a partially enlarged perspective view of the liquid crystal display device according to the embodiment of the present invention.

FIG. 4 is a plan view of a conventional liquid crystal display device.

FIG. 5 is a partially enlarged perspective view of a conventional liquid crystal display device.

FIG. 6 is a plan view of a conventional TCP type liquid crystal display device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Liquid crystal display panel 2 IC chip 3 Wiring board 4a Display area 4b Non-display area 5 Output terminal 6 Output electrode 8 Wiring board connection electrode 10 Wiring board electrode 17 Through hole 18 Anisotropic conductive adhesive which connects a liquid crystal display panel and an IC chip Agent 19 Anisotropic conductive adhesive for connecting wiring board and IC chip 20 Circuit formation surface

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H092 GA48 GA50 GA55 GA59 HA25 JA24 JA46 NA15 NA27 NA29 5G435 AA14 AA18 BB12 EE37 EE42 EE47

Claims (2)

[Claims] An electrode formed on a display panel is connected to a protruding electrode formed on a circuit forming surface in a monolithic semiconductor integrated circuit for performing a display operation of the display panel, and a driving voltage is applied to the monolithic semiconductor integrated circuit. A display device provided with a wiring substrate for supplying a monolithic semiconductor integrated circuit, wherein a through-hole penetrating through the monolithic semiconductor integrated circuit is formed, and a surface opposite to a circuit forming surface of the monolithic semiconductor integrated circuit is formed through the through-hole. Forming a wiring board connection electrode connected to the monolithic semiconductor integrated circuit, connecting a wiring board electrode formed on the wiring board to the wiring board connection electrode, a signal input to the monolithic semiconductor integrated circuit or A display device, wherein power is supplied from the wiring board. 2. A display panel and a monolithic semiconductor integrated circuit, and a connection between the monolithic semiconductor integrated circuit and a wiring board are connected by an adhesive made of an organic resin, respectively, and a connection between the display panel and the monolithic semiconductor integrated circuit is provided. 2. The display device according to claim 1, wherein a glass transition temperature of the organic resin used is higher than a connection temperature between the monolithic semiconductor integrated circuit and the wiring substrate. 3.