Acceptability of Electronic Assemblies Flashcards

According to IPC-A-610, conformal coating that has lifted from the board surface (delamination) on a Class 3 assembly is classified as:

Answer: A defect

Conformal coating delamination is a defect for Class 3 because it compromises environmental protection.

What IPC-A-610 condition describes the presence of white residue under conformal coating that does not affect circuit performance?

Answer: Acceptable condition

White residue under conformal coating that does not affect performance is an acceptable condition per IPC-A-610.

A PCB with measling (internal glass fiber separation visible as white spots) that does not reduce the electrical spacing below minimums is classified as:

Answer: Acceptable for all classes provided spacing is maintained

Measling is acceptable when it does not reduce conductor spacing below minimum electrical clearance requirements.

Per IPC-A-610, a scratch on the PCB surface that does NOT expose base laminate is classified as:

Answer: Acceptable for all classes

Scratches that do not expose base laminate are acceptable for all classes per IPC-A-610.

Which condition describes a hole in the solder joint that penetrates from one surface to another?

Answer: Pinhole/blowhole

A pinhole or blowhole is a void in the solder that penetrates through the solder mass from one surface to the other.

IPC-A-610 requires that solder mask on a PCB should not encroach onto a surface-mount land by more than what amount for Class 3?

Answer: No encroachment allowed

For Class 3, solder mask encroachment onto SMT lands is not permitted, as it can affect solderability.

A component marked with a date code that is illegible after soldering is classified in IPC-A-610 as:

Answer: Acceptable if traceability is maintained by other means

Illegible markings are acceptable if component traceability is maintained through other means such as assembly records.