PCB Peelable Mask

For PCB boards, peelable mask is used to protect selected board areas during the Surface Finish or Assembly Process to keep solder from flowing onto contacts, terminals and plated through holes (PTH). It is also called peel off mask, mask rivets, or blue mask due to its blue colour.

Peelable mask is featured by eliable, time-saving and cost-saving in its application, so it has long surpassed manual masking with heat-resistant tapes.

During the PCB design or layout, here are some guidelines which help everyone to understand the gerber data better.

1. Generally the peel-off mask is applied only to 1 side of the PCB, usually on the solder side.
2. When generating output include the board outline in your peel-off layer(s).
3. Below are some minimum and maximum specifications for peelable mask production:
   Minimum width of any Peel-off element (P): 0.500mm (20mil)
   Maximum coverable hole diameter (H): 6.00mm (236mil)
   Minimum overlap on copper pattern (V): 0.600mm (24mil)
   Minimum clearance to free copper (W): 0.600mm (24mil)
   Minimum distance from PCB outline: 0.500mm (20mil)
   Tolerance on position: +/-0.300mm (12mil)
4. Try to void many different small peel-off areas randomly placed on your PCB. Make the peel-off area as large as possible by connecting the separate peel-off areas wherever practical. This will make it easier to remove the mask after soldering.

SDY Electronic manufactures PCB boards, and provides technical support to customers as well. Kindly please feel free to contact Alex@sdy-pcb.com or our engineer for further details.