What causes the quality problems of solder paste printing?

insmtAt the beginning of the processing program, there is a very important link, that isSolder pastePrinting. The quality of solder paste printing will directly affect our subsequent performanceSMTThe quality of processing and the wholePCBAThe quality of the board. Then what causes these printing defects? What are the solutions? The following is a brief introduction from JJY solder Paste Manufacturer for you:

I. Sharpening defect.

Cause: It is formed due to gaps in the scraper or excessive viscosity of the solder paste.

Solution: InSMTDuring surface mount technology (SMT) processing, appropriately reduce the gap of the squeegee or select solder paste with a suitable viscosity.

Second, the defect of too thin solder paste on the solder pad.

Cause of occurrence:1The template is too thin.2The pressure of the scraper is too high.3The tinting property of the solder paste is poor.

Solution:smtThe operators of the surface mount technology (SMT) manufacturers select templates of suitable thickness;Select solder paste with suitable particle size and viscosity;Reduce the pressure of the scraper.

Three. Defect of inconsistent solder paste thickness on the solder pads.

Cause of occurrence:1The solder paste is not stirred evenly.2The template is not parallel to the printed circuit board.

Solution: Thoroughly stir the solder paste before printing;Adjust the absolute position of the template and the printed circuit board.

4. There are burr defects on the edges and surfaces of the solder paste on the solder pads.

Cause: The viscosity of the solder paste is too low, and the wall of the holes in the template is rough.

Solution: Select solder paste with slightly higher viscosity;Check the etching quality of the holes in the template before printing.

V. Collapse Defects. After printing, the solder paste sinks towards the middle of the solder pad.

Cause of occurrence:1The pressure of the scraper is too high.2The printed circuit board is not firmly positioned.3The viscosity of the solder paste or the metal content is too low.

Solution: Adjust the pressure;Re-fix the printed circuit board;Select solder paste with suitable viscosity.

Shenzhen JJY Industrial Technology Co., Ltd. is a company15As a manufacturer specializing in the research and development and customization of solder paste, lead-free solder paste and leaded solder paste for many years, if you want to learn more about solder paste, please continue to follow JJY Solder Paste Factory and leave a message online to interact with us.