스퀴지 압력의 변화는 인쇄에 큰 영향을 미칩니다. 압력이 너무 작으면 솔더 페이스트가 스텐실 개구부의 바닥에 효과적으로 도달할 수 없고 패드에 잘 침착되지 않습니다. Too much pressure will cause tin The paste is printed too thin and can even damage the stencil.
The ideal state is to just scrape the solder paste from the surface of the stencil. In addition, the hardness of the scraper will also affect the thickness of the solder paste. A squeegee that is too soft (urethane squeegee) will dent the solder paste, and a harder squeegee or metal squeegee is recommended for fine-pitch printing.
스퀴지의 매개 변수에는 재료가 포함됩니다, 스퀴지의 두께와 너비, 블레이드 홀더에 대한 스퀴지의 탄성, and the angle of the squeegee to the steel mesh, 등. 이러한 매개변수는 모두 솔더 페이스트의 분포에 다양한 정도로 영향을 미칩니다. When the angle of the squeegee relative to the stencil is 60°-65°, 솔더 페이스트 인쇄의 품질이 최고입니다..
The relationship between the opening size and the direction of the squeegee should be considered while printing. The traditional printing method of solder paste is that the squeegee runs at a 90° angle along the x or y direction of the stencil. 그 결과, the amount of solder paste on different directions of the device openings is different. It has been verified by experiments that when the length of the opening is parallel to the direction of the squeegee, the thickness of the solder paste is about 60% larger than that when the two are perpendicular. The squeegee is printed in the direction of 45°, which can significantly improve the unbalance of solder paste in the opening direction of different stencils, and at the same time, it can reduce the damage of the squeegee to the openings of fine-pitch stencils.
Empirical formula for SGY Metal SQG squeegee blade pressure
When using a shore screen printing squeegee with a hardness of 80-85, initially apply 1kg of pressure per 50mm of squeegee length.
예를 들어. A 300mm squeegee applies a pressure of 6kg. Gradually reducing the pressure until the solder paste begins to remain on the template and cannot be scraped cleanly, and then increase the pressure by 1kg. Between the time when the solder paste is not clean and when the scraper sinks into the wire hole to dig out the solder paste, there should be an acceptable range of 1-2kg to achieve a good screen printing effect.
How to calculate the blade pressure according to the blade length, please refer to DEK metal squeegee
Here we caculate approximate squeegee blade pressure reference.
200MM 4-6KG
250MM 4-6KG
300MM 5-7KG
350MM 6-8KG
400MM 7-9KG
500MM 8-10KG
If the scraper is new, the pressure can be smaller, if the scraper is old, it can be larger
Moreover.Too many external factors such as whether the squeegee is installed and the printing height will affect the printing solder paste (the steel plate should be scraped clean and the printing quality should be guaranteed)