Causes of Bad Connections
| Bad connections caused by… | Countermeasure / Process Change |
Could be detected in tests as… | ||
| Open | Intermittent Open | High Resistance | ||
| Wire not connected, missing or connected to something else (miswire): | Guided assembly can help prevent miswires. Cirris provides multiple options for guided assembly.
Pin-Sight build aide. |
X | ||
| Flux on mating surface of contact | Learn more about flux on contact surfaces. | X | X | X |
| Cold solder joint | IPC/WHMA 6-20 section 4.3 to 4.9 has excellent information on soldering.
To purchase a copy of A620 visit the WHMA website. |
X | X | X |
| Wire insulation caught in a crimp termination. | Inspection and adjustment for cutting/stripping equipment including replacing stripping blades. | X | X | X |
| Metal oxides on surface of joined metal parts including failure of gas tight connection. | This can be a field problem that is difficult to test since the wiping action of connector engagement usually interrupts the problem for a short time. To learn more about this problem see: | X | X | X |
| Deformed/damaged/worn contact, including fatigue in spring force of contact. | Contacts in mating fixturing connectors that are identical or even undersized may help. Spring probes are blind to these faults. | X | X | X |
| Failure of contact to fully mate because contact is not retained in connector housing. | Contact Retention Problems See Push-Click-PullPin-Sight Learn more about Pin-Sight |
X | X | X |
| Wrong wire gauge for termination. | Check manufactures specifications for terminals/pins against wire guage. Use a splice to change wire size. | X | X | X |
| Loose crimps, including those caused by missing strands of wire. | Crimp force monitoring, Crimp Pull Test:Crimp Size Chart | X | X | X |
| All strands broken (sometimes the result of excessive crimp force). | Crimp force monitoring, Crimp Pull Test:Crimp Size Chart | X | X | X |
| Fixturing to the device-under-test has any of the problems above. | X | X | X | |