Secondary Ion Mass Spectrometry Protocols for Electrodeposited Copper Impurity Quantification
Dynamic SIMS protocols require cesium primary beams and oxygen flooding to accurately quantify trace sulfur, chlorine, and carbon in plated copper films.
Microvia Plating Audit
Meaning
Formal evaluation process that examines the integrity and uniformity of copper deposition in the laser drilled holes of a high density interconnect board. A microvia plating audit focuses on identifying structural weaknesses such as knee cracks, interface separation, plating folds or incomplete filling that could cause circuit failure. It involves the review of statistical process control data, cross-sectional imaging, plating chemistry logs and the results of accelerated thermal cycling tests.
This audit provides the evidence that the manufacturer can consistently produce reliable blind and buried vias.
Procedural Framework
Investigation begins with a review of the chemical bath maintenance logs and the laser drilling parameters used to create the holes. During a microvia plating audit, the inspector verifies that the desmear process has successfully removed all resin debris before the electroless copper stage. Any residue remaining at the bottom of the via can prevent a strong metallurgical bond, leading to latent defects in the field.
Statutory Requirement
Compliance with the GB/T standards for printed circuits is often a condition for supplying to the domestic telecommunications and automotive sectors. While the microvia plating audit is a technical review, its results are used to satisfy the legal requirements for product safety and reliability. The findings are documented in a formal report that specifies any necessary corrective actions for the production line.
Structural Reliability
Observations of the copper grain structure and the thickness of the plating at the corners provide a forecast of the board’s lifespan. This rigorous check protects the buyer from the high costs of mass product recalls.