Outline
This method replaces solder masks or coatings on circuit boards at BGA locations. BGA locations provide unique challenges due to their inaccessibility after reflow, exposure to high temperatures, and the requirement to surround the BGA pads with masks. The exposed Vias and circuits may cause shorting or BGA solder joint starvation.
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Images and Figures![]()
Soldermask Required at BGA Site
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Figure 1: Scrape down to the copper surface to create a barrier to solder flow between pad and via.
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Figure 2: Apply the replacement coating. A wood stick or small dispenser may be used.
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Figure 3: "Dog Bone" area coated with soldermask
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Procedure
Evaluation
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2.4.3 Coating Replacement, Solder Mask, BGA Locations
Procedure covers the methods for replacement of of solder mask on circuit board assemblies at BGA component locations.