Solder composition

Abstract

The present invention discloses a solder composition, and belongs to the welding field. The solder composition comprises, by weight, 3-4wt% of silver, 0.5-1wt% of copper, 0.04-0.07wt% of nickel, 2.5-3.5wt% of bismuth, 0.2-1.5wt% of indium, and the residual of tin, with the total weight of the solder composition being 100wt%. Compared with a traditional solder, the solder composition further comprises 0.2-1.5wt% of indium, while maintaining or increasing properties such as yield strength and tensile strength, urges a welding spot formed by the solder composition to maintain good or better performance in a thermal cycling test without causing a failure test result of intermetallic fracture of the welding spot in a ball shear test after more than once reflow, and has better shear strength.

Description

technical field [0001] The invention relates to the field of soldering, in particular to a solder composition. Background technique [0002] A very important part of consumers' impression of the quality of consumer electronic products depends on whether the consumer electronic products are durable. When a consumer electronic product is subjected to impact, or is used for a long time and operates at different levels of performance, after many cycles of high and low temperature changes, if there is no damage, failure, etc., it can often be used because of its durability. impression of good quality. Whether a consumer electronic product can withstand the test of shock and temperature depends in part on the packaging method used and the quality of the solder used for packaging. There are many ways to package electronic components, for example, one of them is Wafer Level Chip Scale Package (WLCSP). Wafer-level chip size packaging is a packaging technology that uses solder ball...

AI Technical Summary

Problems solved by technology

[0005] This kind of SACNB solder has better yield strength and tensile strength than SAC solder, but when this kind of SACNB solder is made into solder balls and applied to WLCSP packaging, the solder joints formed by it are often due to the ball push test. If the mechanical strength is too high and the brittle fracture of the self-boundary metal is prone to occur, or the redistribution layer (Advanced Packaging, RDL) fracture occurs during the temperature cycle test, and the pad peeling (Pad Peeling) is judged as bad, it cannot pass the test and is pending. improve

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