Hi everybody. I'm new at SMT soldering. I'm using a stencil to print solder paste on PCB. and my board has 0402 components that it make assembling process long so I can't complete a set of board in a day and I have to continue in the next day. what can I do to prevent of drying printed stencil? Can I put it in refrigerator and do it in next day?
Your paste should specify a number of times it is OK for various things to happen.
The two you might care about are the "Stencil Time"/"Working life", which is how long the paste can be out of the pot on your stencil while you print PCBs.
The other is "Tack Time" which is how long the paste can sit on the printed board before you apply components and reflow. Beyond this time the paste can dry out or "slump" (create shorts by spreading out).