Timeline for probable cause of damage to small SMD part: ESD, heat, something else?
Current License: CC BY-SA 3.0
9 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Jan 20, 2018 at 5:45 | vote | accept | kellogs | ||
| Jan 19, 2018 at 12:54 | answer | added | Anonymous | timeline score: 3 | |
| Jan 19, 2018 at 12:42 | history | edited | kellogs | CC BY-SA 3.0 |
added 616 characters in body
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| Jan 19, 2018 at 12:12 | comment | added | Dave Tweed | This question is far too vague. "Care has (not) been exercised" could mean anything at all and conveys no information. More important: Are you sure that the part is damaged, or are you just getting bad solder joints? What kind of solder are you using and how are you applying it? Your description of the handling of the "hot air gun" suggests that you're not using proper rework technique. Is it even temperature controlled? | |
| Jan 19, 2018 at 12:10 | comment | added | Olin Lathrop | Seriously!? You think 36% fallout is only "a bit" high? Even the 10% you mention first is well past unacceptable. | |
| Jan 19, 2018 at 12:08 | answer | added | Olin Lathrop | timeline score: 7 | |
| Jan 19, 2018 at 12:02 | comment | added | Joren Vaes | What kind of part is it? Some accelerometers using polymer micromachining might be sensitive to heat, though I am no authority on that. Have the parts been kept in a propper, dehumidified storage system, or been pre-heated to cook off any absorbed water before assembly? In addition, just strapping your wrist to ground isn't good enough, you need to have a high impedance (but not high enough to prevent dechargeing) to ground, otherwise any charge inside the PCB/chip will be able to transfer too rapidly to ground and cause damage. | |
| Jan 19, 2018 at 11:59 | comment | added | Bimpelrekkie | I think 10% non working after assembly is high as well. Did you follow all precautions, recommendations, soldering profile as recommended in the datasheet? Did you investigate /prove that this component gets damaged? I mean, it could be a bad soldering connection, that would then exclude ESD. Regarding ESD: then something has to cause an ESD event, ESD does not happen "from nowhere". Also often ESD damage does not cause a component to fail immediately but only after some time, unless it is a very strong ESD pulse of course. | |
| Jan 19, 2018 at 11:44 | history | asked | kellogs | CC BY-SA 3.0 |