Quality Assessment

Although nodules in the electrodeposited copper in PTH's are sometimes the result of plating bath contamination, the most prevalent cause seems to be associated with poor drilling. Generally, improper drilling of the holes in PWB's produces sites for the growth of plating nodules. These localised sites are generally areas of smeared epoxy and frayed glass fibres upon which the electrodeposited copper creates irregularities in the form of nodules and bumps. The overall rough wall conditions created by poor drilling conditions also result in a generally overall rough and irregular deposit of copper in the PTH's.