Blank FR4 with soldermask pre-applied - Page 1
Forum section: electronics / general

author: ckambiselis
author_rank: Regular Contributor
timestamp: September 27, 2023, 06:46:28 pm
content: Hi,This probably sounds weird to be looking for, but, has anyone seen blank double sided FR4 boards with matte black/dark color soldermask pre-applied, been sold on any place, preferably Europe?The only product that is close to what I have thought of is presensitized boards but the ones I have found have a transparent coating.Of course one way to get them would be to "design" a blank board and send it to one of the many online fabs, but I suspect they would cost more than a ready made product.ThanksOscar

author: PeteH
author_rank: Unknown
timestamp: September 27, 2023, 07:55:01 pm
content: What size of FR4 sheet? Thickness?

author: abeyer
author_rank: Frequent Contributor
timestamp: September 27, 2023, 08:16:06 pm
content: If it's truly completely "blank" then presumably you aren't soldering anything to it, so the resist properties of solder resist are moot... why not just spray paint (or any other diy finish) a board your desired color?(and there may well be a reason this won't work... but you haven't actually told us what you're trying to do)

author: wraper
author_rank: Unknown
timestamp: September 27, 2023, 08:25:48 pm
content: AFAIK the only similar thing you could get is G-10 (garolite) often sold as 3D printer surface. It comes colored.https://www.fingertechrobotics.com/proddetail.php?prod=garoliteThere is no point making blank FR-4 covered with solder mask. There are other materials if it's for a front panel or similar. People order PCB front panels only because it's a cheapest way how to order a custom panel.

author: ckambiselis
author_rank: Regular Contributor
timestamp: September 28, 2023, 07:16:33 am
content: Standard 1.6mm, 35um, min 10x10cm max 30x30cm.

author: ckambiselis
author_rank: Regular Contributor
timestamp: September 28, 2023, 07:22:51 am
content: The idea is for rapid prototyping or when just 1-2 PCBs are needed, using a diode laser engraver, with a quick test I made on scrap PCB I had laying around I can get to around 5-10mm/s with a 20W laser for the traces, and about 200mm/s for pads and text. How well the spraypaint adheres to the copper is one problem.

author: newto
author_rank: Regular Contributor
timestamp: September 28, 2023, 12:43:24 pm
content: Your best bet is probably to go direct to a PCB manufacturer.You can get five black 10x10cm boards for 2$ and 1.44$ shipping (if you're willing to wait 2-3 weeks for delivery) from JLCPCB with their discount, and more expensive per if you want larger or more than 5 at a time (although still pretty reasonable).If you were ordering a lot of boards, you could probably get a special deal, since you can skip a bunch of process steps (but probably not worth it for them to make a special process if you're only getting a couple)

author: zapta
author_rank: Super Contributor
timestamp: September 29, 2023, 04:36:02 am
content: Can't you just create gerber files of a PCB with solid copper and order from services such as JLCPCB?

author: ealex
author_rank: Frequent Contributor
timestamp: September 29, 2023, 05:16:27 am
content: Quote from: ckambiselis on September 28, 2023, 07:22:51 amI've been using cheap black spray paint for this.I had to try several types to find one that has proper adhesion and burns cleanly - I had a "4W" 450nm laser engraver."burns cleanly" - leaves only ash, nothing sticky.Be aware of the fumes - you'll need good ventilation.

author: ckambiselis
author_rank: Regular Contributor
timestamp: September 29, 2023, 08:42:56 pm
content: What type of spray paint did you find to work the best, acrylic, epoxy... etc?