An in-depth inspection of a printed circuit board (PCB) or printed circuit board assembly (PCA/PCBA) is a quick, cost effective way to ensure the delivery of exceptional quality products. Whether qualifying your own product or screening a subcontractor’s deliverables, a detailed inspection can provide invaluable information about potential process weaknesses that might result in reduced lifespan or reliability.
For quality screening or product qualification, IAL can perform PCB or PCA inspection to the standards set forth in IPC-A-600 and IPC-A-610. This inspection is designed to encompass many of the typical pitfalls of PCB manufacturing; from plating thickness to via registration, solder mask coverage to resin fill, an IPC inspection is a comprehensive examination of many of the key characteristics of an assembly. Many of the features called out by the IPC specs can be inspected non-destructively, and therefore are appropriate as a final inspection or quality screen of a product before shipping; for more in-depth examination, destructive analysis is usually necessary.
PCB/PCA Construction Analysis (sometimes also referred to as Destructive Physical Analysis, or DPA) adds cross-sectional analysis and device delayering to the standard IPC inspection. This deeper dive may target suspected defects buried within the board, like improper via etchback or cracked thru-hole plating, or may simply be part of a more stringent quality control program. In other cases, this type of analysis may be performed in support of a competitive analysis, to look for potential intellectual property infringement or to better understand where a competitor has positioned themselves in the market.
Another, more specialized subset of PCB Inspection is dye penetrant testing (also colloquially referred to as Dye and Pry). Dye penetrant is primarily used in support of failure analysis to look for solder failures. By immersing a PCA in a vat of dye and subjecting it to vacuum and pressure, dye is forced into all available spaces on the PCA – including any cracked or non-wetted solder joints. Suspect devices are then pried from the board, and any failing solder joints can be identified by the presence of the brightly colored dye.
Both unpopulated PCBs and fully populated PCAs can be inspected per IPC-A-600 or IPC-A-610 (respectively). Dye penetrant testing is appropriate for BGAs, LGAs, and QFNs that have not been coated with a conformal coating.
- Continuous monitoring of an established process
- Qualification of a new device or process
- Solder joint inspection and failure analysis