| Bad insulation caused by... | Countermeasure / Process Change | Could be detected* in test as... | |||
| Short | Intermittent Short | IR Failure (leaking) | Dielectric Breakdown (arcing) | ||
| Extraneous wire | Guided assembly Learn about guided assembly here and here |
X | |||
| Mis-registration in IDC connectors (tines have destroyed insulation). | Inspect | X | X | X | |
| Solder bridges | Inspect | X | X | X When a small air gap exists |
|
| Wire insulation that has been damaged and pierced due to compression (cable ties, strain reliefs), heat (heat shrinking, soldering), or stripping (to inner conductors during outer jacket or shield removal). |
See our February 2007 newsletter Learn more about compression errors here |
X | X | X When a small air gap exists |
|
| Loose strands of wire outside of termination, including braided or foil shielding. | Inspect | X | X | X | |
| Loose metal particles such as metal flake or cut strand of wire | Inspect | X | X | X | |
| Combination of leakage and arcing between layers of insulation | Look for non-homogeneous (more than one kind) of insulation. You may need to change sensitivity or else use different cable. | Partial Breakdown | |||
| Burn/carbon trail from breakdown; also some flux residue | See our page on problems with flux | Only with severe carbon trails | X | X | |
| Ionic contamination like salt or RMA flux on connector body | Page that deals with Flux Problems | X | |||
| Hydroscopic plastics/insulators that absorb moisture in humidity | Experiment by checking IR before and after drying connectors or cable in an oven to determine if they are absorbing water. Check manufacture's spec's. PTFE and other Teflon wire types have excellent properties in humidity. | X | |||
| Plywood, paint and most phenolic materials (as often used in fixturing), but only if used as an insulator for connections. | Cirris web page that deals with materials choices. | X | |||
| Fixturing to the device under test that has any of the problems above | X | X | X | X | |
