Preparation method based on single crystal copper bonding wire

Abstract

The invention discloses a preparation method based on single crystal copper bonding wire. The preparation method of the single crystal copper bonding wire is divided into two steps: (1) using continuous casting single crystal copper rod as the single crystal copper The starting material of the bonding wire, at the same time, the single crystal copper bonding wire is drawn by the drawing equipment driven by the AC servo motor with the microcomputer program control, active wire release, and the pulling force accuracy is less than 1mN; (2) The drawn single crystal copper bond The bonding wire is treated with electroplating precious metal palladium with a surface thickness of 0.5um~1um and an organic epoxy coating with a thickness of 1um for double-layer protection; in this way, a single crystal copper bonding wire with multiple protective coatings is finally obtained. Bonding wire has the advantages of low price, high elongation, good mechanical and electrical properties, and good oxidation resistance.

Description

technical field [0001] The invention relates to a method for preparing a bonding wire, in particular to a method for preparing a bonding wire based on single crystal copper and having multiple protective coatings. Background technique [0002] Bonding wire is mainly used in LED packaging, the connection of electrodes or chips of semiconductor devices such as integrated circuits and transistors, and external leads. It is an indispensable material in the semiconductor industry. Its important function determines that the material used as bonding wire needs to have Good electrical conductivity, excellent ductility and chemical stability, etc., in the current LED packaging and IC packaging, gold (Au) bonding wire accounts for more than 90% of the amount. [0003] The price of gold is expensive and rising day by day, which brings heavy cost pressure to low-end LEDs and IC packaging, which are the largest shipments. In addition, the market is driven to require higher chip density, ...

AI Technical Summary

Problems solved by technology

[0005]However, the performance difference between copper (Cu) and gold (Au) brings the following two fatal shortcomings of copper (Cu) bonding wire: 1. Copper (Cu) pull Work hardening during the manufacturing process makes it difficult to draw wires as thin as gold bonding wires; 2. The stability of copper (Cu) is much lower than that of gold (Au), and it is easy to oxidize during storage and welding, resulting in bondage If the performance of the fixed chip deteriorates or even fails, it is necessary to change the current bonding process and carry out anti-oxidation treatment on the bonding wire. Although there is electroplating palladium (Pd) treatment to improve the oxidation resistance, the thickness of the electroplating layer and its effect on The effect of improving oxidation resistance and the influence of soldering performance are still under further study, and these problems lead to great difficulties in the preparation and use of copper-based bonding wires