How to print solder paste on the circuit board

Printing solder paste on the circuit board with a laser stencil and then connecting electronic components to the circuit board through a high-temperature reflow furnace is the most commonly used method in the electronics manufacturing industry today. The printing of solder paste is a bit like painting paint on the wall. The difference is to apply the solder paste to a certain position more accurately and control the amount of solder paste. Therefore, a more accurate special SMT sticker must be used. A sheet stencil to control the printing of solder paste.

Solder paste printing is the basis for the quality of circuit board soldering. The position of solder paste and the amount of tin are more critical. It is often seen that solder paste printing is not good, causing problems such as short circuit and virtual soldering of solder. However, if you really want to print the solder paste well, you have to consider the following factors:

Squeegee type: Printing solder paste should choose the appropriate scraper according to the characteristics of different solder paste or red glue. Currently, the scraper used for solder paste printing is made of stainless steel.

Scraper angle: The angle at which the scraper scrapes the solder paste.

Squeegee pressure: The pressure of the squeegee will affect the amount of solder paste. In principle, when other conditions remain unchanged, the greater the pressure of the scraper, the less the amount of solder paste will be. Because of the high pressure, it is equivalent to compressing the gap between the steel plate and the circuit board.

Squeegee speed: The speed of the scraper will directly affect the shape of solder paste printing and the amount of solder paste, as well as the quality of solder. Generally, the speed of the scraper is set between 20-80mm/s. In principle, the speed of the scraper must match the viscosity of the solder paste. The better the fluidity of the solder paste, the faster the scraper speed should be, otherwise it is easy to seepage.

Demoulding speed of patch stencil:

Whether to use vacuum seat

Is the circuit board deformed?

steel plate opening

Send us an inquiry , we will get back to you soon ,thank you !