Some common bad welding habits in SMT chip mounting machine processing - What are the common problems encountered during SMT chip mounting machine processing by Borey Advanced?

2023-11-02


 

 

 

1. Sticker printing orientation violation

Reason for occurrence: Poor orientation alignment between the template and PCB is the main reason we need to consider. There are also cases of poor template manufacturing, and there is also a situation where the printing accuracy of the printing machine is not satisfactory.

Impact caused: Easy to cause bridging.

Solution: Adjust the template orientation; Adjust the printing machine.

2. Lack of solder paste filling amount

Lack of filling quantity is a phenomenon of insufficient solder paste supply for PCB pads. Unfilled, missing welds, missing welds, dents, etc. are all attributed to a lack of filling quantity. Due to the lack of filling quantity related to various factors such as printing pressure, scraper speed, off screen conditions, solder paste function and condition, template manufacturing method, and poor template cleaning, the most reasonable printing conditions are very important.

3. Penetration phenomenon on the patch

Penetration refers to the phenomenon of flux penetrating around the filled solder pad. The reasons for penetration include excessive pressure on the printing scraper and excessive vacancies in the template and PCB. Methods such as adjusting printing parameters and cleaning the template in a timely manner should be adopted.

4. Bridging phenomenon

Bridging is the phenomenon of solder paste being printed onto adjacent pads. Perhaps the reasons include the orientation violation of the template and PCB, high printing pressure, large printing space, and unclean templates. It is necessary to adjust printing parameters reasonably and clean the template in a timely manner.

5. The solder paste pattern has a depression

Cause of occurrence: Excessive scraper pressure; The hardness of the rubber scraper is not acceptable; The template window is too large.

The impact caused: The amount of solder is not sufficient, which can lead to false soldering and the strength of the solder joint is not sufficient.

Solution: Adjust the printing pressure; Replace with a metal scraper; Improve template window planning.

6. Too much solder paste

Reason for occurrence: The template window specification is too large; The gap between the template and PCB is too large.

The impact: It is easy to form a bridge connection.

Solution: Check the template window specifications; Schedule printing parameters, especially the vacancy of PCB templates.