Localize the electrical event
Record the affected net, resistance or continuity behavior, operating position, and whether the event is intermittent. Use defined electrical measurements to distinguish a trace problem from terminal contact or assembly-joint behavior. Avoid repeatedly flexing the suspect part to demonstrate the fault before documenting its initial state; additional handling can extend the damage.
Crack investigation record
| Investigation item | Question | Evidence to retain |
|---|---|---|
| Electrical behavior | Which path fails and in what position? | Measurement trace and net identity |
| Mechanical location | What deforms or contacts the circuit nearby? | Installed photographs and region overlay |
| Construction | Which material and process produced the sample? | Lot and stackup records |
| Comparison | What single hypothesis is being tested? | Controlled sample and fixture definition |
Map damage to the actual deformation
Compare the location with bend zones, support ends, vias, pad entries, outline features, and enclosure contact. Review conductor routing together with the fixture or product geometry. Check whether the tested assembly follows the intended path. A support shift or installation crease may place deformation somewhere the layout review did not anticipate.
Separate causes through controlled comparison
Retain material identity, copper construction, processing, and movement history with the specimen. Use appropriate examination to distinguish the fracture site and associated features. Test targeted changes to routing, support, construction, or handling without changing everything at once. Confirm the chosen correction under representative duty and update the drawings or process instructions that control the relevant variable.
Before you release the design
- Preserve failed parts in a documented orientation.
- Check connector contacts and joints before assuming a copper fracture.
- Record actual free length and restraint positions.
- Retain first-event data rather than only the final broken sample.
Watch points
- A thicker conductor may change the mechanism without resolving the load path.
Practical questions
Can a crack exist even if the board passes a stationary test?
An intermittent path may reconnect in one position. Define monitoring that represents the reported operating event and preserve the associated mechanical state.
Should I immediately replace the copper type?
Treat material substitution as one hypothesis. Review geometry, processing, support, and handling evidence first, then compare a controlled construction under the same relevant duty.
Technical references
References support the material or design context. Check the exact grade, part number, document revision and project conditions before release.Updated 27 September 2026 · Technical content policy · Engineering guidance supports project review; the agreed drawing defines the build.