In SMT chip processing, most of the defects are caused by solder paste defects. For this kind of production details, we can organize the BOM and Gerber data from the beginning, to the management of the procurement channel of the components, the storage and access control of the solder paste, solder paste printing, SPI solder paste inspection, reflow soldering, etc. Strict control to reduce or avoid soldering defects caused by solder paste problems.

In addition, in PCBA processing, because the same batch of products may have thousands of pieces, the chip processing cycle is relatively long, there may be dry solder paste on the template stencil, or the template opening and the circuit board may not be aligned. Such details may cause unwanted solder paste to be generated at the bottom of the template or even during the processing of PCBA foundry materials, resulting in poor soldering. Next, Sanjing will give you a brief introduction on how to avoid solder paste defects in SMT chip processing.

The printing cycle is fixed in a specific mode during the processing of the full-automatic printing machine. Make sure that the template is on the pad, so that the solder paste printing process is clean. For fine stencils, if damage occurs between thin pins due to the bending of the stencil section, it may cause printing defects and short circuits.

After printing the solder paste, if the operator finds a printing error, he should immediately put the improperly printed board in the soaking solvent, because the solder paste is relatively easy to remove before drying. Conversely, the longer the waiting time, the more difficult it is to remove the solder paste.

In addition, in order to prevent solder paste and other contaminants from remaining on the surface of the circuit board, wipe it with a clean cloth. After soaking, scrub with warm water and spray, and then use a hot air blower for drying. If using a horizontal stencil cleaner, the clean side should be down to allow the solder paste to come off the board.

The above is about how to avoid welding defects in SMT patch processing, I hope it can be helpful to everyone!