Bonding wire

Abstract

The invention discloses a bonding wire. The bonding wire comprises a bonding wire base body and three plating layers, wherein the bonding wire base body is coated with the three plating layers; the bonding wire base body is gold-silver-palladium alloy; the three plating layers comprise a gold plating layer, a palladium plating layer and a platinum plating layer from interior to exterior in sequence; and the platinum plating layer is the thickest among the three plating layers. The bonding wire provided by the invention adopts the three-plating-layer structure; the bonding wire is high in antioxidant performance and sulfidation resistance, and the problem of silver migration can be solved as well; the electronically packaged bonding wire is high in subsequent performance stability; and the bonding wire is low in preparation cost, so that the bonding wire can fully replace the gold wire.

Description

technical field [0001] The invention relates to a bonding wire, in particular to a bonding wire with a three-layer coating structure and a preparation method thereof. Background technique [0002] At present, most of the connections between semiconductor electronic chips in integrated circuits and external lead frames are completed by bonding wires, which is the so-called wire bonding. The process is to fix the bonding wire through a special ceramic nozzle on the bonding equipment, leaving a certain length of bonding wire at the tail, and then melt the tail of the bonding wire into a ball through external arc discharge, and then use the ceramic nozzle The spherical bonding wire is extruded and connected to the electrode of the electronic chip, and finally the other end of the bonding wire is connected to the external lead frame by friction through the movement of the bonding equipment, and it is completed after being encapsulated by plastic resin. To ensure the smooth progr...

AI Technical Summary

Problems solved by technology

However, the cost of gold is expensive, and the cost of bonding gold wire is relatively high. In order to meet market requirements, substitutes for bonding gold wire have been introduced, such as silver alloy wire and gold-plated silver alloy wire.

The manufacturing cost of silver alloy wire is lower, but its resistance to oxidation and vulcanization is lower, so it can only replace gold wire in low-end products

Relatively speaking, gold-plated silver alloy wire can be a better substitute for gold wire. It is coated with a layer of gold on the surface of silver alloy wire, which does improve the anti-oxidation and vulcanization performance of the product without affecting its bonding. However, due to The atomic structure of gold is very similar to that of silver, so gold plating on the surface of silver alloy wire cannot solve the problem of silver migration, and the performance stability of electronic packaging is poor, so gold-plated silver alloy wire still cannot completely replace gold wire

Images