SMT welding defects and their solutions

SMT welding defects and their solutions

1. introduction

 

It is not easy to create and select a surface-mount process that is tailored to the specific product. Because SMT technology involves a number of technical complex systems engineering, any of these factors will affect the quality of the welding of electronic products.

 

The soldering quality of component solder joints directly affects the quality of printed circuit assembly (PWA) and even the whole machine. It is affected by many factors, such as the solderability of solder paste substrate components, placement accuracy and soldering process Wait. During the process of SMT process research and production, we know that reasonable surface mount process technology plays a crucial role in controlling and improving SMT production quality. In this paper, we analyze the causes of several typical welding defects encountered, And put forward the corresponding craft method to solve.

 

2. Several SMT Welding Defects and Their Solutions

 

2-1 Solder ball and reflow solder ball

 

The presence of solder balls indicates that the process is not entirely correct and there is a risk of short circuiting of electronic products and therefore needs to be excluded. International standards for the presence of solder balls are: printed circuit board components in the range of 600 can not appear five solder balls. There are many reasons for producing tin balls. Need to find the root cause.

 

2-1-1 Solder ball in solder ball