Pink PCBs..! - Page 1
Forum section: electronics / general

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: March 07, 2013, 03:37:16 pm
content: Had an interesting problem today - some ENIG (gold finish) PCBs with white resist turned a pale pink when they went through the oven.Apparently something in the ENIG cleaning process affected the ink chemistry (the assembly subcontractor had seen this before).Fortunately I realised that we could just get the resist re-printed & this saved the day with only a day lost.

author: SeanB
author_rank: Super Contributor
timestamp: March 07, 2013, 04:04:08 pm
content: Do it as a feature..........

author: mrflibble
author_rank: Super Contributor
timestamp: March 07, 2013, 05:13:14 pm
content: Quote from: SeanB on March 07, 2013, 04:04:08 pmWhat he said. Add a flower motif to the silkscreen, slap an ar-suckmy-duino on it somewhere and hawk your wares on kickstarter. Bound to sell!

author: Bored@Work
author_rank: Super Contributor
timestamp: March 07, 2013, 06:11:27 pm
content: Time to connect to your inner feminine side.

author: Smokey
author_rank: Super Contributor
timestamp: March 07, 2013, 07:00:40 pm
content: before and after pictures?

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: March 07, 2013, 08:34:35 pm
content: Quote from: Smokey on March 07, 2013, 07:00:40 pm

author: nicknails
author_rank: Regular Contributor
timestamp: March 08, 2013, 01:17:00 am
content: We use white resist on all of our boards and I've seen this happen a few times. Not to that extent, more of just a pinkish hue. We've never really seen it as a problem and all of our parts are encapsulated.

author: deephaven
author_rank: Frequent Contributor
timestamp: March 08, 2013, 09:18:16 am
content: Why not introduce a line of electronic Barbie Dolls? You could call them Barbduinos

author: kc0ngu
author_rank: Contributor
timestamp: May 05, 2013, 07:42:36 pm
content: Does it only happen over ENIG?If it happens with regular HASL, it might not be the ENIG, it might be migration of a blue, violet or similar pigment/dye in the resist. White inks sometimes use these added colors to increase the apparent 'whiteness' of the white ink, especially if a cheap or low quality white pigment is being used. Most times these added colors dont show, but reflow and solder temps can play rough with (poorly) formulated inks/resists.Not a real answer I know, just my 2cents from 30+ years of designing these coatings and (trying to) solve similar issues on the PCB shop floor.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: May 05, 2013, 09:18:00 pm
content: The PCBs were re-printed with the same resist ink, and came out fine, so pretty sure it was something that happenned during plating.The PCBs were for this BTW...http://www.uva.co.uk/work/continuum

author: EEVblog
author_rank: Unknown
timestamp: May 05, 2013, 10:12:03 pm
content: Quote from: mikeselectricstuff on March 07, 2013, 03:37:16 pmYes, I've seen this before quite a few times, not uncommon. Although I thought it was pretty much history these days.

author: jmole
author_rank: Regular Contributor
timestamp: May 05, 2013, 11:28:36 pm
content: Quote from: mikeselectricstuff on May 05, 2013, 09:18:00 pmbeautiful piece. how'd you end up working with these folks?

author: kc0ngu
author_rank: Contributor
timestamp: May 06, 2013, 12:46:48 am
content: Quote from: mikeselectricstuff on May 05, 2013, 09:18:00 pmOK, thanks for the update Mike, I will have to have a think about what else might be in going on, appreciate your work (and videos's) as always, impressive end result/installation.

author: Corporate666
author_rank: Unknown
timestamp: May 15, 2013, 11:46:25 pm
content: Can you disclose who the PCB manufacturer was?I just got a very expensive quantity of white soldermasked boards with ENIG plating.... haven't used any yet but maybe I should run one through the reflow process to see if it turns pink!