The IPC-6012 provides max. bow and twist not exceed 0.75% for the PCB from SMB to SMT. This article will show you how to control the bow and twist of PCB. Let’s find out the prevention methods of PCB bow and twist:
-
Engineering design.
The arrangement of PP between layers should correspond one-to-one; Core and PP should use the same brand products for multilayer PCB. The inner and outer copper areas should be close, and dummy copper can be added when necessary.
-
Baking lamination before cutting.
It is generally required to bake 150 degrees for 6 to 10 hours to remove moisture from the board and making the resin solidifies completely.
-
Aligned the warp and weft of prepreg for multilayer PCB.
-
Eliminate the stress after cold laminate and trim the deckle edge.
-
Baking the board before the drill,150 degrees for 4 hours.
-
The thin PCB does not apply to the machine brush, recommended chemical cleaning.
-
After the HAL/LF-HAL, the PCB must be placed on the flat marble or steel plate and make clean after natural cooling.
