IPC-A-610 inspection basics
What the IPC-A-610 acceptability standard covers, how its product classes and inspection conditions work, and the solder defects that come up most often at the bench.
- PCBA
- Inspection
- Soldering
IPC-A-610, Acceptability of Electronic Assemblies, is the reference most electronics manufacturers use to decide whether a finished circuit board assembly passes visual inspection. It describes, with photos and drawings, what good and bad workmanship looks like for solder joints, component placement, hardware, cleanliness and more.
How it relates to other standards
| Standard | What it answers |
|---|---|
| IPC-A-610 | Does the finished assembly look acceptable? (visual acceptance criteria) |
| J-STD-001 | What are the requirements for the soldering process and materials? |
| IPC-7711/7721 | How should rework, modification and repair be carried out? |
Product classes
The same joint can pass on one product and fail on another, depending on the class the customer specifies:
- Class 1 — General electronic products. The main requirement is that the assembly works.
- Class 2 — Dedicated service electronics. Continued performance and longer life expected; uninterrupted service is desired but not critical.
- Class 3 — High-performance / harsh-environment electronics. Equipment that must work when needed, with no downtime tolerated.
Inspection conditions
Each feature is judged against four conditions:
- Target — close to ideal; the preferred result.
- Acceptable — not ideal, but maintains integrity and reliability.
- Process indicator — not a defect, but a sign the process should be looked at.
- Defect — not acceptable for the class; the item must be reworked, repaired, scrapped or dispositioned.
Defects that come up often
- Bridging — solder joining conductors that should be separate.
- Insufficient solder / poor wetting — not enough fillet, or solder that beads up instead of flowing onto the land and lead.
- Disturbed or cold joints — rough, grainy or cracked surfaces from movement or too little heat during cooling.
- Tombstoning — a chip component standing on one end, connected on only one side.
- Misalignment — parts skewed or offset beyond the allowed overhang.
- Solder balls and splatter — loose solder that can migrate and short.
- Lifted leads or pads and component damage such as cracked bodies.
- Contamination — flux residue or debris where cleanliness is required.
Rework versus repair
Rework brings an item back into full conformance with the original drawings and specifications. Repair restores function but may not fully match the original documentation, so it normally needs customer approval. Knowing which one you are doing matters as much as the soldering itself.
This page is a general summary for orientation. Always work from the current revision of the standard and the customer’s documentation.