Borey Advanced - Problems encountered during SMT SMT mounting machine processing

2024-03-08


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

2. The reason for the depression in the solder paste pattern is that the scraper pressure is too high; The hardness of the glue scraper is not acceptable; The template window is too large.

The impact caused: Inadequate amount of solder, prone to false soldering, and insufficient strength of solder joints.

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

3. The reason for the excessive amount of solder paste: the template window specification is too large; The gap between the template and PCB is too large.

The impact is that it can easily form a bridge connection.

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

4. Reasons for violating the orientation of SMT printing: Poor alignment of the template and PCB orientation is the main reason we need to consider. There are also cases of poor template manufacturing, and another situation is that 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.

5. Lack of solder paste filling, which is a phenomenon of insufficient solder paste supply for PCB pads. Unfilled, lack of welding, insufficient welding, depression, etc. are all attributed to insufficient filling amount. Due to the lack of factors related to printing pressure, scraper speed, off screen conditions, solder paste function and condition, template manufacturing method, poor template cleaning, etc., the most reasonable printing conditions are crucial.

6. Penetration phenomenon on surface mount 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.