JPH0677291A - Method and apparatus for removing whisker of film carrier - Google Patents

Abstract

PURPOSE:To almost perfectly remove whiskers with such a simplified method and apparatus by removing whiskers between conductor patterns through application of ultrasonic beam to the plated film carrier within the refining water or the heated one. CONSTITUTION:On the occasion of manufacturing a film carrier having a conductor pattern formed by copper, whiskers between conductor patterns are removed by application of ultrasonic beam to the plated film carrier within the refining water or heated refining water. Moreover, in the apparatus for manufacturing a film carrier having conductor pattern formed by copper, a water tank is provided as a post-processing apparatus of the plating vessel and an ultrasonic beam generating apparatus is comprised within the water tank. For instance, in the process for manufacturing a film carrier having conductor pattern formed by electrolytic copper foil, a film carrier having completed the tin plating is guided into the water tank filled with the hot water of 80 deg.C produced from the refining water and is then placed under the irradiation with ultrasonic beam for 15 seconds from the ultrasonic beam generating apparatus.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for removing whiskers formed after tin-plating a film carrier.

[0002]

2. Description of the Related Art A film carrier method (TAB) is known as a mounting technology for semiconductor devices.
The film carrier used for this TAB is one in which a conductor pattern is formed on a copper foil attached to a flexible insulating film such as polyester resin by a photoresist method, and then Au is used.
It is tin-plated for bonding to bumps. In such a film carrier, needle-like crystals called whiskers are generated after tin plating, which is a major cause of short circuits between the conductor patterns.

As an attempt to suppress or prevent the generation of the whiskers, various studies have been conducted by changing the chemical composition of the plating solution, but this method causes a large amount of abnormal precipitation on the conductor pattern, It was a product that could not be used. Although efforts have been made to suppress the generation of whiskers by devising the pretreatment method for plating, it has not been possible to prevent the generation of whiskers. In addition, as a post-plating treatment, attempts were made to remove whiskers generated by post-treatment liquids such as acids and bases, but the plating surface reacts with the post-treatment liquid and deteriorates to make it unusable. It was something that

As described above, many studies have been made to date as a method for suppressing or preventing the generation of whiskers, but the present situation is that no such method has been found.

In view of the above situation, it is an object of the present invention to provide a method and a device capable of removing whiskers almost completely with a simpler method and device.

[0006]

According to the method of the present invention, when a film carrier having a conductor pattern of copper or the like is produced, the film carrier after plating is subjected to ultrasonic waves in purified water or warm water thereof, The whiskers between the conductor patterns are removed, and the device of the present invention is provided with a water tank as a post-treatment device for the plating tank, and an ultrasonic wave generator is incorporated in the water tank. It was done.

In order to remove whiskers generated after plating, the device of the present invention incorporates an ultrasonic wave generator capable of causing cavitation in a water tank provided as a post-treatment tank for the plating tank. In another device, the film carrier after plating is dipped, and cavitation is caused in purified water or its heated water by an ultrasonic wave generator, and this action cuts and removes the whiskers from the root.

The water filled in the water tank does not deteriorate the surface of the film carrier. Therefore, if purified water or heated water thereof is used, particularly hot water of 70 to 80 ° C. can be used because the washing effect by the hot water can be obtained at the same time. .

[0009]

[Example] In the process of manufacturing a film carrier having an electro-deposited copper foil as a conductor pattern, the number of whiskers generated in the output side outer lead portion after completion of tin plating was 168 per piece. This film carrier
It was introduced into a water tank filled with warm water of 80 ° C. prepared from purified water, and ultrasonic waves were irradiated for 15 seconds by an ultrasonic wave generator.
Furthermore, when this film carrier was dried and annealed and the number of pseudo whiskers was counted, 0 and all whiskers could be removed.

[0010]

As described above, according to the present invention, whiskers generated between conductor patterns can be reliably removed in a short time without deteriorating the plating surface. Further, in the device of the present invention, since the film carrier and the ultrasonic wave generation device do not come into contact with each other, the lead is not deformed.

Claims (2)

[Claims] 1. When manufacturing a film carrier having a conductor pattern of copper or the like, the film carrier after plating is subjected to ultrasonic waves in purified water or its warm water to remove whiskers between the conductor patterns. A method for removing whiskers from a film carrier. 2. A whisker for a film carrier, characterized in that, in a film carrier manufacturing apparatus using copper or the like as a conductor pattern, a water tank is provided as a post-processing apparatus for the plating tank, and an ultrasonic wave generator is incorporated in the water tank. Removal device.