Circuit Board Testing

Cross sectional measurements of plated through hole (PTH) quality, ball grid arrays (BGA), inner plane separation, inner plane registration, wicking, and dielectric layer thickness are all good indicators of circuit board quality.

XRF Measurement (ASTM B568) can non-destructively measure the thickness of metallic coatings to the nearest micro-inch. If the gold plating, nickel plating, tin plating, solder, or other coatings are not the right thickness then they may not provide adequate protection or contact resistance.

Circuit board assembly is a major contributor to the overall quality of a circuit board. Optical microscope inspection for flux residue, poor solder joints, inaccurate placement, delamination, or other defects is a good first step in a quality program. Solderability (ASTM B678) measurements indicate how well a surface is prepared prior to populating with components. The actual strength of connectors and adhesion of leads can be measured with custom tensile strength measurements. Destructive physical analysis (DPA) can be used to locate the source of failures.

Temperature and humidity chambers are used for environmental cycling of circuit boards for initial burn in purposes or to simulate extreme performance conditions which could cause failure over time. Solder shock testing is used to show how well a circuit board is likely to maintain integrity during soldering processes.