Trouble in Your Tank: Optimizing the Soldermask Process, Part 3
In previous columns (May and June, 2013) related to the soldermask process, I presented critical information on ink properties, methods of soldermask application, tack drying, etc. In this column, the exposure process is detailed. This includes exposure units, UV lamps, the phototool, and the overall exposure energy.
Exposure Process
Once the soldermask ink is applied and properly tack dried, it is now necessary to expose the soldermask. Optimum exposure is critical in attaining a quality image. Essentially, exposure works hand-in-hand with development to maintain fine features and tight soldermask dams. Make no mistake: Proper exposure is the first step in the proper definition of the soldermask image. In order to achieve optimum exposure results the operator must consider the following:
- Exposure units;
- UV lamps;
- The photo tool or photographic template; and
- Exposure energy.
All of these factors or critical aspects are important in order to optimize the exposure process. Each will now be presented in some detail.Read the full column here.Editor's Note: This column originally appeared in the October 2013 issue of The PCB Magazine.