PCB SMT SMD Stencil Scrubbing Process Introduction

One-stop PCBA smart manufacturers today for you to talk about SMT SMD processing stencil how to scrub?SMT SMD processing stencil scrubbing process. In the SMT SMD production process, due to the deformation of the PCB substrate, positioning is not allowed, support is not in place, design and a series of reasons, in the process of solder paste printing stencil and PCB substrate pads is difficult to form an ideal sealing state. In the SMT process of solder paste printing process there will always be a little solder paste from the stencil and PCB gap between the extrusion out of the bottom of the stencil. These solder paste if not processed in the subsequent PCBA processing will affect the back of the circuit board surface cleaning and even open sidewalls will be adhering to the solder paste, affecting the transfer of solder paste, so the bottom of the stencil residual solder paste scrubbing is essential to us in this processing session of a process. Below to share with you a brief SMT SMD processing stencil scrubbing process.

SMT Mounter Stencil Scrubbing Process

In SMT SMD processing we generally use automatic scrubbing method for removal. Scrubbing modes are wet wipe, vacuum wipe and dry wipe, usually using a combination of wet wipe/vacuum wipe/dry wipe process, i.e. wet wipe first, then vacuum wipe and dry wipe. It is also possible to use a combination of wet-vacuum-dry scrubbing. The purpose of wet wiping is to remove solder paste residue from the bottom of the stencil, while the purpose of dry wiping is to remove cleaning agent and flux residue from the bottom. Vacuum wipe the nominal hope that the printing template aperture residual solder paste suction, but the actual effectiveness depends on the template aperture area ratio, may be an effective function of the aperture wall into the cleaning agent suction, so as not to affect the first time after wiping the screen after the printing effect.

In the actual PCBA processing in addition to the automatic cleaning function, but also need to carry out regular manual decontamination. Because in the long term a large number of printing solder paste in the process, the bottom of the stencil will be components are contaminated, so as to form a hard scab around the mesh, and this kind of thing is the need for processors to carry out regular manual removal.

Generally after the manual wet wipe should be dry wipe again or leave it for a few minutes, otherwise it may lead to the first one or two boards under the tin is not good. Because the manual wiping stencil for wet wiping, too much cleaning agent penetrated into the opening hole wall, the rapid evaporation of cleaning agent leads to increased solder paste viscosity, which affects the SMT SMD under tin.

SMT SMD processing stencil how to scrub? SMT SMD processing stencil scrubbing process of knowledge, want to know more, you can pay attention to the PEAK PCBA, if you need to know more about PCB prototyping, SMT SMD, PCBA processing related technical knowledge, welcome to leave a message to get!