A countersink is a conical hole cut into a manufactured object, or the cutter used to cut such a hole. A common use is to allow the head of a countersunk bolt or screw, when placed in the hole, to sit flush with or below the surface of the surrounding material.
Peelable Solder Masks (also known as strippable mask or blue-mask) are applied by screen-printing, act as in-process protection and are removed either after processing at the PCB manufacturer or at the assembler.
Peelable Solder Masks, provide such protection in soldering processes like wave soldering, reflow soldering or hot-air solder leveling (HASL). Reliable, time-saving and cost-saving in their application, they have long surpassed manual masking with heat-resistant tapes.
At Jaapson PCB, we always use Atotech material: SD 2843. It has the below features and advantages: Excellent definition due to optimized Rheology Excellent adhesive strength and mechanical stability Resistant during HASL High chemical resistance Protecting during plating processes by peelable soldermask