Clear soldermask and black core PCB - Page 1
Forum section: electronics / general

author: Boogami
author_rank: Contributor
timestamp: July 15, 2018, 10:15:27 pm
content: Hello,does anyone know a chinese PCB fab that can do a PCB like thiswith transparent soldermask and black core FR4 I presume? I am looking for a pcb manufacturer that can do cheap pcb prototypes but with this awesome combo.

author: tsman
author_rank: Frequent Contributor
timestamp: July 15, 2018, 10:37:57 pm
content: I doubt any of the quick & cheap prototyping places will do that combination. Coloured soldermask and plain FR4 is pretty much the limit of those cheap deals so if you need black PCB but clear soldermask then be prepared to pay for a custom run.

author: IconicPCB
author_rank: Super Contributor
timestamp: July 15, 2018, 10:38:23 pm
content: It must come at an awesome cost.It would be awesome if you could afford it.Awesome

author: rea5245
author_rank: Frequent Contributor
timestamp: July 15, 2018, 10:49:17 pm
content: Would it be cool enough to use regular FR-4 with black soldermask, but don't have the soldermask cover any of the traces?Speaking of the traces, what's the finish on that board? It doesn't look like HASL or ENIG.I googled for that image and it's the Analogue Nt, a Nintendo NES emulator. According to an article about it, the board is a "custom black PCB with exposed and raised copper traces, finished with a transparent solder mask."- Bob

author: sleemanj
author_rank: Super Contributor
timestamp: July 15, 2018, 10:54:57 pm
content: Quote from: rea5245 on July 15, 2018, 10:49:17 pmHASL / ENIG is done after solder mask, so only on the pads. The trace colour is just what the bare copper looks like after it's coated in the clear soldermask.

author: Gary.M
author_rank: Regular Contributor
timestamp: July 16, 2018, 08:49:44 pm
content: I don't know where you'd get that done, but it certainly does look nice!Quote from: Boogami on July 15, 2018, 10:15:27 pm

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: July 16, 2018, 09:20:55 pm
content: Clear soldermask can be found, but not from cheap proto services.Coloured FR4 will have significant MOQ and leadtime - forget cheap protos.A 4 layer board with inner planes and clear soldermask might get you close-ish to that appearance though.Or you could fake it with a black resist and silkscreen layer duplicating the trace pattern.

author: IconicPCB
author_rank: Super Contributor
timestamp: July 16, 2018, 10:53:16 pm
content: Awesome cost.

author: Gary.M
author_rank: Regular Contributor
timestamp: July 16, 2018, 11:39:57 pm
content: Quote from: IconicPCB on July 16, 2018, 10:53:16 pmSometimes aesthetics count.

author: IconicPCB
author_rank: Super Contributor
timestamp: July 16, 2018, 11:56:00 pm
content: No doubt.But our OP is " ...looking for a pcb manufacturer that can do cheap pcb prototypes but with this awesome combo..."

author: Gary.M
author_rank: Regular Contributor
timestamp: July 16, 2018, 11:59:18 pm
content: Quote from: IconicPCB on July 16, 2018, 11:56:00 pmYeah he was hopeful, no problem with that. And awesome is a figure of speech widely used amongst younger people. No need to scorch him over that.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: July 17, 2018, 02:26:42 am
content: That's probably CG. Looks good enough that it could be real, but it's also very unusual as you've noticed.Incidentally, clear soldermask seems to have been more common back in the day; Tektronix used this back in the 70s. Don't know if that's because it was a film process (with attendant poor registration tolerance -- not very suitable for SMT), or that that's how they preferred to do it. But at the same time, a lot of places went with bare copper (probably HASL board, followed by wave soldering?), which was probably a bit of a mess for various characteristics, but was probably cheap and fast...I don't know offhand of anywhere that has clear soldermask.Tim

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: July 17, 2018, 08:15:40 am
content: Quote from: T3sl4co1l on July 17, 2018, 02:26:42 amI've had clear mask from my UK supplier - attached pic is clear resist over ENIG.Eurocircuits also offer it.

author: TERRA Operative
author_rank: Super Contributor
timestamp: July 17, 2018, 09:04:00 am
content: If you could get the black PCB but get them to do the ENIG process on all copper before the clear solder mask, that would look really nice....

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: July 17, 2018, 09:56:16 am
content: Quote from: TERRA Operative on July 17, 2018, 09:04:00 amThat's what we did for the boards above.Another option may be to get a black resist layer as a negative of the copper layer - probably easier and cheaper than getting black FR4.Of course you need a sensible, preferably local PCB place that you can talk to for doing special builds like this.

author: reboots
author_rank: Regular Contributor
timestamp: July 17, 2018, 07:53:24 pm
content: I don't know about black prepreg. But I do know that Rogers RO4000/RO4350 laminates, typically used for high-performance RF applications, are pure white. Rogers material is available from most better fabs--for a significant price premium.https://www.rogerscorp.com/acs/producttypes/9/RO4000-Laminates.aspx

author: Hydron
author_rank: Super Contributor
timestamp: July 18, 2018, 08:20:29 pm
content: Looks like that pic isn't CG:https://www.theverge.com/2015/6/26/8850397/analogue-nt-premium-nes-nintendo-consoleCertainly looks striking (other than that green 3-pin reg replacement module they've stuck in there!). Shame it's almost certainly out of hobbyist reach.

author: reboots
author_rank: Regular Contributor
timestamp: July 23, 2018, 09:40:53 pm
content: This doesn't address OP's question in the slightest, but someone is selling black FR4 laminate on eBay:https://www.ebay.com/itm/162430211254Could add a little something to DIY projects.

author: In Vacuo Veritas
author_rank: Frequent Contributor
timestamp: July 24, 2018, 02:24:25 pm
content: It is also possible to have two layers of soldermask. The customer is king.One black layer that covers the substrate but leaves all copper exposed, then a clear layer over the copper except pads.

author: reboots
author_rank: Regular Contributor
timestamp: January 08, 2020, 08:04:04 pm
content: Resurrecting this thread to mention that (US-based) OSH Park does now offer clear solder mask on black prepreg with their After Dark service:https://docs.oshpark.com/services/afterdark/Same price as standard prototype boards, somewhat longer lead time.

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: March 01, 2020, 04:29:00 pm
content: Anyone know how to order this service from OSH Park? I uploaded a design and it keeps showing me the purple color scheme. I can't find anywhere to select "After Dark".

author: jfiresto
author_rank: Frequent Contributor
timestamp: March 01, 2020, 07:27:03 pm
content: After you upload your design and clickOrder, a list of options will appear, including a check box:[ ]After Dark (Black Substrate + Clear Mask)Just click on it.

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: March 01, 2020, 07:51:24 pm
content: Duh, don't know how I missed that ...

author: nardev
author_rank: Unknown
timestamp: March 01, 2020, 08:02:18 pm
content: In some other topics i already mentioned a company from my country, they told me that if required, they can even mix up color which is not standard and make panels for you. Though i have no idea how much would that cost but they say they can do it.Feel free to contact them if you want.https://pcb.ba/p.s. i have been asking about the turqise blue, sth like that and they said, possible.

author: jfiresto
author_rank: Frequent Contributor
timestamp: March 01, 2020, 08:04:22 pm
content: Quote from: Alex Eisenhut on March 01, 2020, 07:51:24 pmDon't feel too bad – that suggests the GUI could be more "discoverable".

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: March 01, 2020, 11:03:50 pm
content: Quote from: jfiresto on March 01, 2020, 08:04:22 pmIt blanks out the "After Dark" option if you select "Super Swift".

author: jfiresto
author_rank: Frequent Contributor
timestamp: March 02, 2020, 09:12:38 am
content: Quote from: Alex Eisenhut on March 01, 2020, 11:03:50 pmAt one point, I managed to tick "2 oz. copper" and "After Dark", two incompatible options, which then grayed and lockedallthe options. At least I could see what I could not change.I had to cancel the order and submit another.I will ask OSH Park if the page is a work in progress.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: March 02, 2020, 01:11:39 pm
content: Use your browser to your advantage!- Right-click the offending boxes, select Inspect Element- Find the offending <input> tags- Right-click, Edit as HTML- Addchecked=falsebetween the last attribute and the final '>' (or anywhere in the middle really, as long as you aren't stomping other attributes).Could also make a short bookmarklet that resets input fields, unchecking everything; I'd have to think about it a moment to come up with something though.Tim

author: I wanted a rude username
author_rank: Frequent Contributor
timestamp: March 03, 2020, 12:31:55 am
content: Quote from: T3sl4co1l on March 02, 2020, 01:11:39 pmAs long as it's using a proper HTML form you could just create an <input type="reset"> button and let the browser do all the work.

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: March 03, 2020, 03:54:10 am
content: In any case it's super cheap. I whipped up a little test jig I'll probably see in April.

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: March 05, 2020, 03:18:34 am
content: And the panel is complete, more than a week earlier than they anticipated. This option must be popular. I hope my thingy looks as good as I think it will!

author: jfiresto
author_rank: Frequent Contributor
timestamp: March 05, 2020, 07:59:58 am
content: OSH Park must be getting a fair amount of business – or we have been very lucky. Last night, I sent them a design for their regular processing. They sent the panel to the fab seven minutes later.

author: Ranayna
author_rank: Super Contributor
timestamp: March 05, 2020, 08:41:58 am
content: One has to assume that due to the delivery issues that the Chinese fabs are facing at the moment, OSHPark, as US based manufacturer, gets significantly more customers.

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: March 12, 2020, 10:20:40 pm
content: It shipped today. Now I worry if it will work. I didn't put much effort into it....