JPH05291740A - Terminal connecting device - Google Patents

Abstract

PURPOSE:To improve reliability of connecting a terminal by bringing a pressure member having a low thermal expansion coefficient into contact with a surface in contact with a flexible printed board (FPC) to suppress elongation of the FPC, deviation of the FPC due to thermal deformation of an elastic part in heating, pressurizing connection of an electrode terminal of liquid crystal type or other flat display panel to the terminal of the FPC. CONSTITUTION:A pressurized part of a terminal connecting device uses a pressure member 3 having a low thermal expansion coefficient such as a metal foil, a ceramic sheet, etc., as a surface in contact with an FPC 9, a multilayer structure formed inside through an elastic element 2, brings the FPC 9 into contact with a hard board 8 of a flat display panel through the member 3 at the times of heating, pressure-connecting terminals of the PFC 9, and suppresses a deviation of the PFC 9 due to elongation of the PFC 9, a distortion of a buffer A.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention connects an electrode terminal portion formed on a rigid substrate such as a glass substrate of a liquid crystal type or other flat display panel and a terminal portion formed on a corresponding flexible wiring board (FPC). The present invention relates to a terminal connecting device that does.

[0002]

2. Description of the Related Art Connection between a panel electrode terminal portion formed on a hard substrate such as glass of a liquid crystal type or other flat display panel and a substrate terminal portion of another FPC is
A thermoplastic or thermosetting adhesive for a binder, in which an anisotropic conductive film as an electrode connecting material is sandwiched between the electrode terminal portion and the FPC terminal portion to bring the conductive particles into pressure contact with each other by appropriately controlled pressure and heat. As a connecting device, a terminal connecting device as shown in FIGS. 3 and 4 is cited as a connecting device. In the terminal connecting device of FIG. 3, the anisotropic conductive film 10 is cured by the irradiation heat of the infrared lamp 4 that has passed through the hard substrate 8 to face the first terminal electrode portion 8a (panel electrode terminal portion) of the hard substrate 8. FP
The configuration is such that it is connected to the second terminal electrode portion 9a (FPC terminal portion) of C9.

The pressing mechanism 7 of the connecting device is provided with a columnar elastic body 15 on the upper surface thereof, and the glass plate 6 on the lower surface of the light-shielding mask 5.
And the first terminal electrode portion 8a and the second terminal electrode portion 9a are sandwiched between the elastic body 15 and the elastic body 15 made of silicon rubber or the like. It is a thing. The connection device cures the anisotropic conductive film 10 by a heat ray that is emitted from the infrared lamp 4 and is transmitted through the glass plate 6 and the first terminal electrode portion 8a to irradiate the second terminal electrode portion 9a. ..

In the connection device of FIG. 4, a heating head 13 such as a pulse tool or a constant heat (heater block) is provided above a mounting table 14, and the FPC 9 and the hard substrate 8 sandwiching the anisotropic conductive film 10 are, for example, The second terminal electrode portion 9a formed on the FPC 9 having a small thickness and a large thermal conductivity.
Is placed on the mounting table 14 in a higher order and the heating head heated to a predetermined heating temperature is applied to the FPC 9 to apply pressure to cure the anisotropic conductive film 10 by heat conduction.
The pressurizing structure of this device has an elastic sheet 12 made of silicon rubber or the like in order to obtain the uniform pressure of the rigid substrate 8 and the first and second terminal electrode portions 8a, 9a which are the connected portions of the FPC 9 by the mounting base 14 and the heating head 13. It has a structure sandwiching.

[0005]

In the heating connection by the above-mentioned conventional terminal connecting device, in addition to the thermal expansion of the FPC itself, the coefficient of thermal expansion of the elastic body or elastic sheet of the device is F.
Since it is larger than the thermal expansion coefficient of PC, F
The PC is pulled in the extending direction, and the extension is promoted. In addition, when the balance of pressure and heat received due to the difference in the film thickness of FPC and the warp of the hard substrate, the elastic body and elastic sheet such as silicon rubber are deformed abnormally, causing the FPC to shift from the fixed position. It was. The influence of such expansion and displacement of the FPC is apt to cause poor connection or short circuit as the wiring pitch of the FPC becomes fine or the size of the connection portion of the FPC becomes long, which is an important issue for reliability of connection. I had it.

[0006]

SUMMARY OF THE INVENTION The present invention is based on a homogeneously rigid metal or glass as a base in a pressurizing portion of a terminal connecting device, and sandwiches a thin elastic material such as a rubber sheet on the outside thereof.
A pressure member having a low coefficient of thermal expansion, such as a metal foil or a ceramic, is integrally attached to form a pressure member having a multilayer structure, and a pressure member having a low coefficient of thermal expansion such as a metal foil or a ceramic sheet on the surface of the pressure member. The FPC and the hard substrate are welded together by heating and pressurizing through.

[0007]

By using a material having a low coefficient of thermal expansion such as a metal foil or a ceramic as the pressing member in contact with the FPC, the electrode terminal portion of the hard substrate and the surface of the pressing portion during the pressure heating operation of the FPC terminal portion are used. Since the expansion of the pressing member is small, the FPC is not pulled in the expanding direction, the pressing member itself does not undergo thermal deformation or distortion, and the elastic sheet of the inner layer follows the undulations and warps of the FPC and the hard substrate to be uniform. Contact the FPC by applying sufficient pressure.

[0008]

1 and 2 show an embodiment of the device of the present invention. FIG. 1 shows a terminal connection provided with a pressurizing portion A in which the elastic body 15 of the prior art terminal connection device shown in FIG. 3 is improved. In the device
The pressing portion A has a columnar quartz glass provided on the upper surface of the pressing mechanism 7 as a base 1, an elastic body 2 made of silicon rubber is attached to the upper end thereof, and the surface of the elastic body is coated with Teflon. This is a structure in which a pressure member 3 made of a low thermal expansion coefficient sheet of SUS foil is integrally attached. When the Teflon coating is heated and pressed, the resin of the anisotropic conductive film should be
It is surface-treated in order to prevent it from adhering to the metal foil surface even if it protrudes from the FPC. The structure having the glass 6, the light-shielding mask 5, and the infrared lamp 4 above the pressing portion A is the same as that of the above-mentioned conventional device.

The base 1 of the pressing portion A may be a homogeneous rigid material such as metal other than the above quartz glass. The silicon rubber of the elastic body 2 may be another cushioning material, but the thinner the thickness, the better in order to prevent the mounted FPC from being displaced due to the buckling of the rubber. The pressing member 3 located at the interface with the FPC is not limited to the SUS foil, of course, and the lower the coefficient of thermal expansion of the alternative member is, the more effective it is. There is no problem with the material, but if the material has a rigid surface, it is difficult to apply uniform pressure because it does not correspond to the roughness or warpage of the FPC or substrate surface, so it follows the undulation or warpage between the FPC and the substrate. In order to facilitate uniform pressurization, it is effective to make each of the above materials into a sheet and interpose a sheet of an elastic material such as silicon rubber.

The embodiment of FIG. 2 is a terminal connecting device in which the elastic sheet 12 made of silicone rubber in the prior art device of FIG. 4 is improved, and the outer layer of the elastic sheet 12 is made of SUS foil having a Teflon coating to have a low thermal expansion coefficient. The structure is characterized in that a pressure sheet A'having a multi-layered structure is provided as the pressure pressing member 11 having a plurality of layers. By providing the pressing member 11 of the SUS foil on the surface, the structure is such that the SUS foil is located at the contact portion with the FPC 9 when the electrode terminal portion and the FPC terminal portion are connected by heating and pressurization. The elastic sheet 12 such as a large silicone rubber does not directly contact the FPC. Incidentally, in the embodiments, reference numerals not particularly explained are the same as those in the conventional example.

[0011]

The terminal connecting device of the present invention having the above-described structure and operation is used when infrared rays are radiated in the pressurizing section or the FPC terminal section is sandwiched between the electrode terminal section and the FPC terminal section on the hard substrate by heating and pressing. Since the sheet having a low coefficient of thermal expansion is brought into contact with the FPC, the FPC having a smaller coefficient of thermal expansion than the conventional elastic body having a large coefficient of thermal expansion greatly expands together with the elastic body, or the heat of the elastic body is increased. In contrast to the problem of connection failure (not connected) or short circuit caused by deformation due to deformation, which is a serious problem in reliability of terminal connection, in comparison with FPC when connecting FPC with liquid crystal type or other flat display panel The elongation can be suppressed to 1/3 to 1/2, which is effective for connection with a fine pitch, and can improve the yield of the liquid crystal panel. It is also applicable to the connection of the terminal portion of the electrode terminal, a FPC rats display panel.

[Brief description of drawings]

FIG. 1 is a schematic diagram of an infrared irradiation type terminal connection device.

FIG. 2 is a schematic view of a heating head type terminal connecting device.

FIG. 3 is a schematic diagram of a conventional infrared irradiation type terminal connection device.

FIG. 4 is a schematic view of a conventional heating head type terminal connecting device.

[Explanation of symbols]

 A pressure portion A ′ pressure sheet 1 base 2 elastic body 3, 11 pressure member 4 infrared lamp 5 light-shielding mask 7 pressure mechanism 8 hard substrate 9 FPC (flexible wiring substrate) 10 anisotropic conductive film 12 elastic sheet 13 Heating head

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yuji Matsuda 22-22 Nagaike-cho, Abeno-ku, Osaka City, Osaka Prefecture Sharp Corporation

Claims (1)

[Claims] 1. An electrode connecting material is pressure-melted between an electrode terminal portion formed on a hard substrate such as a glass substrate of a flat display panel such as a liquid crystal facing each other and a terminal portion of a flexible wiring board (FPC). In a terminal connecting device for connecting both terminal parts by means of a metal foil, a ceramic sheet or the like as a pressing member contacting the FPC,
A sheet having a lower coefficient of thermal expansion than that of the above is used, and an elastic body such as a rubber sheet is added to the inner layer to form a multilayer sheet structure, and the hard substrate and the FPC are heated and pressed through the pressing member. A terminal connecting device characterized by being bonded.