JPH0576182B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a wire clamp plate, and more particularly to a clamp plate that directly clamps a wire in a wire bonding device used to connect semiconductor chips with wires such as gold wire. be.

(Prior art) A wire bonding device that connects semiconductor chips with wires such as gold wires is equipped with a clamp plate at its tip that directly clamps the wire. , fixing plate 1
The movable plate 2 is movable toward the fixed plate. The wire clamp plates 1 and 2 are used to connect semiconductor chips one after another while repeatedly clamping and unclamping the wire W, and it is required that the continuity of wire bonding be excellent.

That is, if the wire sticks to the tip of the tool during wire bonding, the wire bonding will be interrupted and the continuity of the bonding will deteriorate. Therefore, various improvement measures are being considered.
For example, as in Japanese Patent Laid-Open No. 63-78544, it has been proposed to vibrate the tool ultrasonically to prevent the wire from sticking.

(Problems to be Solved by the Invention) On the other hand, in order to improve the continuity of wire bonding, wire clamp devices are being studied from the viewpoint of materials.

In other words, conventional wire clamp plates made of cermets such as carbide have been used, but this has the disadvantage that the wire comes into contact with the clamp plate as it travels, causing the clamp plate to wear out and become unusable for long periods of time. Recently, TiN has been applied to ruby.
Coatings began to be used.

The reason why ruby is coated with TiN is
This is because when Ruby is used alone, static electricity is generated due to contact with the running wires, and the static electricity causes the wires to curl or become tangled, making them unusable.

However, even if ruby is coated with TiN, its adhesion is not very good and it will eventually peel off, making it impossible to use it for a long time.

Therefore, the ruby clamp plate from which the TiN has peeled off is coated with TiN again and used, but the service life is short and replacement work is frequent, and it is also costly to re-coat the TiN, making it economical. There were problems in terms of gender, etc.

The present invention was made to solve the problems of the prior art described above, and provides a clamper for clamping wires when connecting semiconductor chips.
The object of the present invention is to provide a wire clamp plate that has excellent wear resistance, has a long life, and can significantly improve the continuity of wire bonding.

(Means for Solving the Problems) In order to achieve the above object, the present inventor created a coating material for the clamp plate that directly clamps the wire at its tip, which has high hardness, wear resistance, and static electricity. To prevent this, we decided to coat it with TiN or TiC, which has good electrical conductivity.
In this case, we conducted extensive experimental research on materials that would not easily peel off after coating.

As a result, although TiN and TiC have the above-mentioned advantages, the coating material, i.e., the wire clamp plate, does not have good adhesion and peels when used with conventional cermet or ruby. It has been discovered that, in limited cases, excellent adhesion with TiN and TiC can be achieved, and the present invention has been made here.

That is, in short, the clamper according to the present invention has a structure in which the clamp plate that directly sandwiches the wire at the tip is a sintered silicon carbide body, and the sintered silicon carbide body is coated with TiN or TiC.

The present invention will be explained in more detail below.

Wire clamp plates made of sintered silicon carbide (SiC) are generally manufactured by forming granules of fine silicon carbide powder into a predetermined shape using a mold press, degreasing and sintering, and then grinding and polishing them. TiN or
Finish the surface to be coated with TiC to a mirror finish.

Silicon carbide sintered body has superior thermal conductivity compared to ruby, alumina, etc., so it can easily dissipate the frictional heat generated when the wire contacts the clamp plate while running, which helps reduce wear. . However, a silicon carbide sintered body alone cannot be used because it generates static electricity, and it also lacks wear resistance, so there is a limit to how long it can be used.

Therefore, in the present invention, a silicon carbide sintered body is coated with either TiN or TiC.

In other words, as mentioned above, TiN and TiC have high hardness and wear resistance, and have good conductivity, so they can prevent the generation of static electricity, but when the clamp plate is made of ruby as in the past, there is a problem of peeling. There is. Therefore, the present inventor conducted various studies on materials that have good adhesion to TiN and TiC, and as a result, it was found that silicon carbide sintered bodies have very good adhesion to TiN and TiC. However _{, Al2O3}
We also considered a sintered body, but the adhesion was not good, and even if we coated it with TiN or TiC, it would peel off.

Note that there are no particular restrictions on the coating method for TiN or TiC. For example, various PVD coating methods are available, and ion plating is easy. A suitable coating thickness is 1.0 to 5.0 μm.

(Example) Next, examples of the present invention will be shown.

Example A disk with a diameter of 4 mm, a thickness of 1 mm, and a surface roughness of 0.03 μm was manufactured from silicon carbide sintered body, and for this disk,
A 2μm TiN coating was applied using arc discharge high vacuum ion plating method.

As a result of attaching this clamp plate to the clamper and using it at a bonding speed of 0.2 seconds, the coating surface wore out after 10 months of use, and it was time to replace it.

In addition, TiC was applied to the above disk to a thickness of 2 μm using the same method.
coating was carried out.

As a result of attaching this clamp plate to the clamper and using it at a bonding speed of 0.2 seconds, the coating surface wore out after 12 months of use, and it was time to replace it.

Comparative example Ruby, diameter 4mm, thickness 1mm, surface roughness
A 0.03 μm disk was manufactured, and TiN was applied to this disk.
A 2 μm thick coating was applied using arc discharge high vacuum ion plating method.

When this clamp plate was attached to a clamper and used at a bonding speed of 0.2 seconds, the coating began to peel off after 6 months.

(Effects of the Invention) As explained above, according to the present invention, the wire clamp plate is made of silicon carbide sintered body, and TiN
Or, since it is coated with TiC, it has excellent abrasion resistance and good adhesion.Therefore, the coating will not peel off and static electricity will not be generated even if the wire comes into contact with it, so it can be used for a long time. , the continuity of wire bonding can be significantly improved, and the cost required for producing the clamp plate can be reduced.

[Brief explanation of the drawing]

FIG. 1 is an explanatory sectional view showing a clamp plate in a wire bonding device. 1...Fixed plate, 2...Movable plate.

Claims (1)

[Claims] 1. In a clamper that clamps a wire when wiring a semiconductor chip, the clamp plate that directly clamps the wire at its tip is made of a sintered silicon carbide body,
A wire clamp plate characterized in that the silicon carbide sintered body is coated with one of TiN and TiC.