JPH0622350U - Adhesive film for joining electronic components - Google Patents

Abstract

(57) [Summary] [Object] To provide an adhesive film suitable for preventing electronic parts from being damaged by static electricity. [Structure] An adhesive film formed by forming an adhesive layer on a peelable substrate having conductivity.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an adhesive film suitable for forming a circuit or electrodes between two circuit boards in a liquid crystal panel or the like and connecting both circuits, for example.

[0002]

[Prior art]

 In the case of connecting electronic components on the circuit between two circuit boards, a styrene-based or polyester-based thermoplastic or an epoxy is used as an adhesive that bonds them together and provides electrical continuity between these circuits. Thermosetting materials such as those based on silicone and silicone are known. In this case, when a conductive particle is mixed in the adhesive to obtain an electrical connection in the thickness direction of the adhesive by pressurization (for example, JP-A-55-104007), when connecting without using the conductive particle. There is one (for example, Japanese Unexamined Patent Publication No. 60-262430) in which electrical connection is obtained by the fine unevenness of the electrode surface due to the above pressure. These adhesives form an adhesive layer on a peelable substrate (hereinafter referred to as a separator) made of a polyester film or paper surface-treated with a release agent such as silicone, and a low polarity film such as polyethylene or tetrafluoroethylene. However, it is often supplied as a film. If it is in the form of a film, application work is unnecessary and it can be obtained as a long product with a certain thickness. Therefore, it is possible to automate the adhesive formation on the circuit, and it is easy to obtain high reliability of connection. In these connections, the adhesive film is temporarily connected to one circuit by pressure or the like, then the separator is peeled off, and the adhesive film is aligned with the other circuit before the main connection.

[0003]

[Problems to be solved by the device]

 In many cases, static electricity is generated in the temporary connection and the separator peeling process, and electronic components such as semiconductor chips and thin film transistors around the connection circuit are destroyed. As a countermeasure for this, humidification of the work atmosphere and a blower for removing static electricity were performed, but they were insufficient. Since these electronic parts do not operate normally and are damaged, it is necessary to replace them with non-defective ones, resulting in a great deal of labor and resource loss. The present invention is to provide an adhesive film suitable for preventing electronic parts from being damaged by static electricity.

[0004]

[Means for Solving the Problems]

 The present invention relates to an adhesive film formed by forming an adhesive layer on a releasable base material, wherein the releasable base material has conductivity, and an adhesive film for joining electronic components. The present invention will be described below with reference to the drawings. FIG. 1 is a schematic sectional view showing the structure of the present invention. In FIG. 1, 1 is a conductive base material, and it is necessary that the adhesive layer shown in 2 can be peeled off. The conductive base material 1 is typically a conductive plastic film obtained by mixing a conductive filler such as carbon or metal particles with a plastic such as polypropylene, polyvinyl chloride or polyethylene, and other metal foils, nets, etc. There is.

As the adhesive layer 2, basically, all general adhesives can be applied, but so-called adhesives for electronic parts whose impurity ions and curing speed are strictly controlled are preferable. These may be either thermoplastic type or thermosetting type, and may be a composite or mixture of these. In addition, even if conductive particles are mixed in the adhesive to obtain an electrical connection in the thickness direction of the adhesive by applying pressure, etc., without using conductive particles, for example, by applying pressure during connection, fine unevenness on the electrode surface may occur. It may be one that obtains electrical connection. A mixture of conductive particles is preferable because it is less susceptible to the effects of the electrode surface and the circuit surface and can be applied to a wide range of adherends.

To make the conductive base material 1 a peelable separator, a low-polarity film such as polyethylene or tetrafluoroethylene is used as the material of the conductive plastic film, or the surface of the base material 1 is roughened. The shape may be dealt with by forming a wavy line or providing a wavy line. Further, as shown in FIG. 2, the surface of the conductive substrate 1 may be surface-treated with a release agent 3 such as silicone. It is preferable that the release agent 3 is formed on both sides of the conductive base material 1 because it can be easily unwound when formed into a tape-shaped roll. Further, as shown in FIG. 3, a composite of a plastic film 4 and a metal 5 foil, a mesh or the like is also preferable since it is easy to obtain a balance between conductivity and mechanical strength. When using the adhesive film according to the present invention, it is preferable to use a humidifying atmosphere in the working atmosphere and to use it together with a conventional means such as a static electricity removing blower in order to surely obtain the effect of preventing electrostatic breakdown.

[0007]

[Action]

 According to the present invention, since the releasable base material has conductivity, static electricity generated in the connecting step can be removed by grounding or the like by utilizing the conductivity of the base material. Therefore, it is possible to prevent the electronic parts from being damaged by static electricity.

[0008]

【Example】

Example 1 A conductive plastic film having a thickness of 50 μm and made of a mixture of polyethylene and carbon fibers (surface resistance 10 ³ Ω-cm) was coated with an epoxy adhesive using a roll coater to obtain an adhesive film having a thickness of 20 μm after drying. This film was easy to unwind when it was used as a tape-shaped roll. According to the method shown in FIG. 4, the adhesive film 12 of the present embodiment is grounded to the connection terminal 11 of the continuous product (TAB) of the flexible wiring board on which the IC chip is mounted by the metal roll which also serves as the contactor 14 from the separator 13. While taking 15, the temporary connection was made by the press 16. Then, while removing the separator, the main connection was made to the glass terminal 17 of the liquid crystal display. The IC chip was not destroyed by static electricity in this example.

Example 2 As in Example 1, except that 1% by volume of conductive particles having a particle size of 5 μm and having a thin layer of Ni / Au on the surface of polystyrene spheres were mixed with an epoxy adhesive. When evaluated in the same manner as in Example 1, there was no destruction of the IC chip due to static electricity. Comparative Examples 1-2 As in Examples 1-2, polyethylene containing no carbon fibers was used as the separator. When evaluated in the same manner as in Example 1, many breakages of the IC chip due to static electricity occurred.

Example 3 As in Example 2, as a separator, both sides of a composite film prepared by vapor deposition of an Al metal thin film on a 25 μm polyester film were subjected to silicone treatment as a release agent. When the structure shown in FIG. 3 was obtained and evaluated in the same manner as in Example 1, there was no destruction of the IC chip due to static electricity. The ground of this example was taken out by applying a pin-shaped contact from the adhesive surface so as to face the Al metal thin film. In the case of this example, the release agent is insulating, but it is considered that static electricity is grounded through the Al metal thin film due to its thinness of about 1 μm or less and the inclusion of conductive particles in the adhesive. . Generally, the withstand voltage level is 10 V with respect to the thickness of the insulating layer of 1 μm. In addition, as an application of this example, it is also possible to take out the contactor in the form of a blade so as to bite into the adhesive layer and directly contact with the Al metal thin film.

Example 4 Similar to Example 2, but a polyvinyl carbamate-based treatment as a release agent was performed on both surfaces of a rolled copper foil 18 μm as a separator. The rolled copper foil had a smooth surface and was also flexible, allowing continuous winding and good rewindability. When evaluated in the same manner as in Example 1, it was possible to prevent electrostatic breakdown.

[0012]

[Effect of device]

 As described above, according to the present invention, it is possible to prevent the electronic parts from being destroyed by static electricity, and therefore it is possible to significantly reduce defects in the connection process.

[Brief description of drawings]

FIG. 1 is a schematic sectional view showing a configuration of an embodiment of the present invention.

FIG. 2 is a schematic sectional view showing the configuration of another embodiment of the present invention.

FIG. 3 is a schematic sectional view showing the configuration of another embodiment of the present invention.

FIG. 4 is a schematic cross-sectional view for explaining the usage of the adhesive film according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Conductive base material 2 Adhesive 3 Release agent 4 Film 5 Metal 11 Connection terminal part of FPC board 12 Adhesive film 13 Separator 14 Contact 15 Ground 16 Press 17 Terminal part of glass substrate

Claims (1)

[Scope of utility model registration request] 1. An adhesive film comprising an adhesive layer formed on a peelable base material, wherein the peelable base material has electrical conductivity.