JPS6194085A - Flat display unit - 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 Field of Industrial Application The present invention relates to a flat panel display device such as a liquid crystal display device, a plasma display device, or an EL display device, and particularly to a group of electrodes led out to the outside of the display device and a semiconductor device for driving the display device. The present invention relates to a flat panel display device equipped with an improved electrode connection structure that connects a flexible circuit board electrode group on which a flexible circuit board is mounted.

Conventional configuration and its problems In order to drive a flat panel display device as described above, the external electrode group of the display device and the flexible circuit board electrode group on which the driving semiconductor device is mounted are connected. There is a need for this, and for this purpose several methods have been adopted, such as those listed below.

(1) A metal material suitable for thermal fusion, such as Au or Sn, is applied to the surface of the electrode to be connected by plating or vapor deposition, and the electrodes are connected by thermal fusion.

(2) Anisotropic conductive rubber in which conductive parts and non-conductive parts are arranged alternately is sandwiched between electrodes and pressed together by applying external pressure.

(3) An anisotropic conductive film made into a sheet by dispersing a conductive dispersant in a resin is sandwiched between electrodes and bonded by thermocompression.

Each of these methods has the following problems.

(1) A treatment process for the electrode surface is required, and only a limited number of electrode materials can be used. Moreover, once connected, it cannot be replaced.

(2) The anisotropic conductive rubber itself has a high internal resistance of several tens of ohms or more, and requires a jig to apply external pressure.

(3) Heat resistance due to the use of resin as the adhesive;
Poor moisture resistance.

Furthermore, a common problem is that all of the three methods described above only connect the $i sides, and a method for fixing the flexible substrate must be prepared separately.

OBJECTS OF THE INVENTION An object of the present invention is to integrate a flexible circuit board and a connecting part,
It is an object of the present invention to provide an electrode connection structure that makes the mounting body compact, realizes high reliability and low resistance of the connection part, and also allows the replacement of the circuit board.

Structure of the Invention The structure of the present invention includes an external lead-out electrode group of a flat panel display, and an electrode group corresponding to the external lead-out electrode group in a flexible circuit board on which a semiconductor device for driving the flat panel display is mounted. The flexible circuit board is stacked one on top of the other and pressed against each other by a spring member within the frame, and a part of the flexible circuit board is attached to the frame.

Description of examples The basic configuration of the present invention is shown in FIG.

The semiconductor device 2 that drives the flat panel display 1 is mounted on a flexible circuit board 3, and a part of the flexible circuit board 3 has a connection spring 4 inscribed therein. It is fixed within a groove 5a of a frame 5 having a cross-sectional structure of a square shape. After alignment, the external lead-out electrode group 6 of the flat panel display 1 and the electrode group 7 of the flexible circuit board 3 are inserted into the groove 5a of the frame body 5 in a state of overlapping and direct contact. . A flexible circuit board 3 is connected to a connecting spring 4 via a cushioned sheet 8.
The structure is such that the external lead-out electrode group 6 and the circuit board electrode group 7 are pressed against each other by the connection spring 4 while the glass substrate 9 is inscribed in the frame 5 under the pressing force.

With the configuration shown in Figure 1, the glass substrate 9 and Hilex glass (260 x 80 x 2.471 m
), and an ITO electrode (
512 Au electrodes were formed on a polyimide flexible circuit board 3 at a pitch of 0.32 mm,
The other end was connected to one on which 16 driving semiconductor devices were mounted. The external dimension of the connection frame 5 is 260 m in length.
It has a width of 35πm, a height of 12'Inl, and is made of At. The semiconductor device mounting portion of the flexible circuit board 3 is formed of phosphor bronze with a thickness of 0.37/Im at the 35 WIN width portion of the frame 5. It was fixed by being inscribed in the groove 5a. After aligning the external lead-out electrodes 6 and the flexible circuit board electrodes γ, the electrode portions 7 of the flexible circuit board 3 are bonded using a silicone rubber sheet with a thickness of 0.3 m1N as a cushioning sheet 8.
was fixed to the back surface of the connector, inserted into the connection frame 5, and pressure-welded. In this case, the connection resistance should be 10 or less. Stored at a constant temperature of 126°C, and stored at a constant temperature and humidity of 86°C and 85°C for 1000 hours.
Even after that, it was less than twice the initial value. Even after repeated insertion and withdrawal 500 times, the connection resistance value was less than twice the initial value.

In FIG. 2, the flexible circuit board 3 is bent and fixed to the connection frame 5 in order to make the size of the connection structure more compact. The other configurations are the same as the embodiment shown in FIG.
Identical parts are given the same numbers. The outer dimensions of the connection frame 5 are 260 mm in length and 20π in width.

With a height of 12mm, the semiconductor device mounting part was fixed to the 20πm width part, and the signal wiring part was fixed to the 12mm height part. By doing so, it was possible to reduce the external volume of the connected structure to approximately %.

FIG. 3 shows a case where the connection spring 4 in the connection structure is placed below the glass substrate, and effective connection can be achieved when the number of electrodes is large or when the connection area is large. Furthermore, a cushioning sheet 8 was also used on the lower side of the glass substrate 9. Other parts similar to those in FIG. 2 are given the same numbers and their explanations will be omitted.

FIG. 4 shows a case under the same conditions as in FIG. 1, with silicone rubber sheets covering both sides of the object to be connected as cushioning sheets 8. If the glass substrate 9 is thin, the glass substrate 9 may be distorted and a uniform connection may not be obtained. 8, the pressure was applied uniformly and a good connection was obtained.

Next, for example, the electrode connections of an EL display device were carried out under the conditions described in the embodiment of FIG. In the EL display device, the pitch of the external lead-out electrode part is 0.32.
ynyr with 256 scanning electrodes and 1024 signal electrodes was used. Drive voltage 100■.

When the device was driven at a maximum current of 80 mA, good driving was achieved. The shape of the connection spring in the present invention is not limited to that shown in FIG. 1, and is shown in FIG.
, b, and c, and the plate thickness can be arbitrarily changed depending on the pressure and shape required for pressure welding.

The following table shows the connection resistance values when the electrode material is changed. This is the average connection resistance when 1024 electrodes were measured with an electrode pitch of 0.32.

In this way, connections with low connection resistance can be achieved regardless of the electrode material.

Effect of the invention 9 Vapor The effects of the present invention are that the electrode connector and the circuit board on which the semiconductor device for driving the display device is mounted can be integrated and made compact, and that it is easy to handle. 81
-Achieving high reliability and low connection resistance regardless of 1.
It is possible to realize a connection that is resistant to high temperatures and high humidity.

[Brief explanation of drawings]

FIG. 5 is a perspective view showing another embodiment. FIG. 5 is a sectional view showing an example of the shape of a spring used in the connection structure in the embodiment of the present invention. 1...Flat type display body, 2...Semiconductor device for driving a display device, 3...Flexible circuit board, 4...
... Connection spring, 5 ... Frame body, 6 ... External electrode group, 7 ... Electrode group of flexible circuit board,
8... Cushioning sheet, 9... Glass substrate. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
figure? Figure 2・[Mi≦ed--i≦勺-1 Figure 3 Figure 4?・(7 meters Figure 5 (α) (-6-) (Riotsu

Claims (2)

[Claims] (1) A flexible circuit board having a flat display body having a group of external lead-out electrodes arranged in parallel, and a semiconductor device for driving the flat display body and having an electrode group facing the external lead-out electrode group. A frame body having a U-shaped cross-sectional structure on which a part of the flexible circuit board is mounted, and a spring member inscribed in a groove of the frame body, A flat panel display device characterized in that an externally led electrode group and an electrode group of the flexible circuit board are overlapped, and the electrode groups are brought into pressure contact with each other by the spring material within the frame. (2) The back surface of the electrode group of the flexible circuit board where the external lead-out electrode group of the flat panel display and the electrode group of the flexible circuit board are overlapped, or the back surface of the electrode group of the flexible circuit board and the flat plate. 2. The flat panel display device according to claim 1, wherein cushioning sheets are arranged on both back surfaces of the external lead-out electrode group of the display device.