Timeline for Black Pad. Will heat remove the gold from an ENIG finish?
Current License: CC BY-SA 4.0
18 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Nov 7 at 0:36 | comment | added | bitsmack | @mbrig it's a few years later, but there's an answer now :) | |
| Nov 7 at 0:34 | vote | accept | bitsmack | ||
| Nov 6 at 10:32 | answer | added | Mircea Ilie Balasoiu | timeline score: 3 | |
| Jan 7, 2023 at 1:41 | comment | added | mbrig | Did you ever get an answer on this? I'm curious | |
| Nov 5, 2019 at 19:57 | answer | added | user16222 | timeline score: 2 | |
| Oct 29, 2019 at 8:01 | history | bumped | CommunityBot | This question has answers that may be good or bad; the system has marked it active so that they can be reviewed. | |
| Sep 26, 2019 at 22:09 | comment | added | rdtsc | There appear to be little metallic balls of something near every trouble-spot. My guess is it is an undesired metallic contaminant, perhaps phosphorus, left over from the ENIG process (and thus is the fab's "fault".) Before reflow temperatures, the balls are not visible because they are so small. Heating allows them to merge into larger droplets. I'd order a prototype run from a different fab and send those back (minus the chips of course.) :) | |
| Sep 26, 2019 at 21:00 | history | tweeted | twitter.com/StackElectronix/status/1177327193732632576 | ||
| Sep 26, 2019 at 20:47 | comment | added | bitsmack | @SunnyskyguyEE75 Do you mean the white blobs? It's a feeble attempt at silkscreening a tiny part :-) A 0.4mm-pitch WLCSP sits inside those corner markings. | |
| Sep 26, 2019 at 20:43 | comment | added | D.A.S. | Is that the bottom side glue? | |
| Sep 26, 2019 at 20:32 | history | edited | bitsmack | CC BY-SA 4.0 |
even more info
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| Sep 26, 2019 at 18:57 | comment | added | bitsmack | @VoltageSpike This is from a partially-assembled array. They soldered/populated some of the individual boards, and left the others alone. These images are from the left-over boards which weren't soldered, but went through the oven because they were on the same array. | |
| Sep 26, 2019 at 18:54 | comment | added | Voltage Spike♦ | If they went through an assembly process, what was it? why are there no components or solder on the board? Assembly usually means 'putting the components on the board' | |
| Sep 26, 2019 at 18:53 | comment | added | bitsmack | @VoltageSpike Agreed :-) They were clean before they went through the assembly process! | |
| Sep 26, 2019 at 18:52 | history | edited | bitsmack | CC BY-SA 4.0 |
better image, additional info
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| Sep 26, 2019 at 18:49 | history | edited | Voltage Spike♦ | CC BY-SA 4.0 |
added 88 characters in body
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| Sep 26, 2019 at 18:48 | comment | added | Voltage Spike♦ | Those pads need to be clean before a BGA is put on them, it looks like it's the same material as the soldermask. It would be unusual for an assembly process to deposit material. | |
| Sep 26, 2019 at 18:23 | history | asked | bitsmack | CC BY-SA 4.0 |