What Is Soldermask
The masks clearance will be approximately 1.5mil-2mils (0.038mm - 0.05mm) larger than the copper characteristic on all sides to ensure no masks is by accident printed on the copper. This is to stop masks from by accident being utilized over the copper surface, thereby lowering the solderable floor space making soldering more difficult. We see design information created by all types of software program packages and engineers of various degrees of expertise. Sometimes the solder mask clearances are precisely the identical size because the copper pad they are exposing, sometimes they are much larger or smaller. Anytime there's a regular or 'most popular' of something, economies of scale invariably begin kicking in.
LPI mask is a messy liquid process and totally different colors can't be swapped on the fly. Of course, you can have a separate mask line for different colours, however that is likely price and area prohibitive in some factories. It occurs, typically a mistake is made with the original artwork and something gets covered with masks that shouldn't be. Before sending your information in for manufacturing, turn on your prime copper and high solder masks layers at the similar time to ensure every thing that must be open in the mask layer is open.
Since most boards are made with standard green, the manufacturing line is optimized for this shade. Other colors are possible however so as to use a unique colour, the tools must be cleaned, calibrated, and prepped for the color change.
Another danger of black solder mask is the way in which it absorbs warmth during reflow. You should scale down the configuration file or make sure the temperature sensor is always positioned on the board. Screen printing additionally tends to show light brown in the course of the reflow course of, which may be because the circuit board beneath absorbs lots of heat. The contrast between traces, planes, and no-copper areas could be very low, so you should zoom in to examine for manufacturing defects.
From the front, the distinction between screen printing and solder mask is very excessive, so if your circuit board has many half-numbers, the blue PCB solder mask may be for you. Besides temporary solder mask, polyimide tape (commonly called Kapton Tape, a brand of E.I. du Pont de Nemours) or pre-shaped silicone masking boots can be utilized to cowl select areas of the circuit board. A Non-Solder Mask Defined pad is a conventional solder mask clearance that is larger than the copper pad it is exposing.