Gerbers to Include To Avoid Having a Solder Mask - Page 1
Forum section: electronics / general

author: bostonman
author_rank: Super Contributor
timestamp: February 13, 2025, 12:16:45 am
content: Recently I laid out a PCB and showed some friends. Unfortunately they don't understand what a PCB is, so I had the idea to make (and possibly spend the money ordering) one without a solder mask so the traces show. I added a middle layer to use as the copper pour ground and thought the top and bottom would show all the traces.Attached are the files I included to JLCPCB to see the gerber view, however, it looked like the board was covered in green covering all the vias/holes/pads.Did I include a layer I shouldn't have?

author: thm_w
author_rank: Super Contributor
timestamp: February 13, 2025, 01:53:23 am
content: There is no GTS or GBS file so it looks ok to me:https://jlcpcb.com/help/article/Suggested-Naming-PatternsBut if you don't include a solder mask layer, its probably going to confuse them. So at the very least put that in the notes that you don't want any solder mask.The JLC preview isn't trustworthy in giving you an accurate representation of the end result.

author: bostonman
author_rank: Super Contributor
timestamp: February 13, 2025, 02:12:50 am
content: QuoteThat's what I thought too.Thanks for the link, but I already saw that months ago when I ordered another board (and I saved it for future reference).So if I include 'top' (which I assume is some assembly print) and 'top silk', ignoring a middle and bottom layer, that's enough to get the whole top of the board made correctly?What happens with the traces and stuff, do they still get soldered or remain copper?As you may tell, I'm a bit confused on one or two (or maybe three) of the layers and their purpose. The silk screen layer is obvious, but then there is paste, mask, and assembly.

author: oPossum
author_rank: Super Contributor
timestamp: February 13, 2025, 03:08:07 am
content: Soldermask is a negative layer, so just draw a polygon on those layers that covers the entire board.

author: bostonman
author_rank: Super Contributor
timestamp: February 13, 2025, 03:34:30 am
content: QuoteA negative layer? I assume it inverts?Why draw a polygon on that layer or layers?

author: oPossum
author_rank: Super Contributor
timestamp: February 13, 2025, 04:01:58 am
content: Drawing on the mask layer removes the mask. So to remove all the mask just cover the entire board with a polygon on the mask layer.If there is no file for the mask then nothing will be removed from the mask layer and the entire board will be covered with mask.

author: bostonman
author_rank: Super Contributor
timestamp: February 13, 2025, 04:28:42 am
content: Ahhh that looks exactly what I'd want should I desire spending the money just to give people who don't understand what a PCB is.If a solder mask isn't included, per your picture, does that mean the traces will be bare copper or covered with solder so they are silver?

author: oPossum
author_rank: Super Contributor
timestamp: February 13, 2025, 04:42:55 am
content: Traces will be covered with ENIG (gold), HASL (tin) or OSP (typically clear-ish) as specified on the order.

author: oPossum
author_rank: Super Contributor
timestamp: February 13, 2025, 04:56:50 am
content: An other option would be yellow soldermask. It shows the traces quite clearly.

author: oPossum
author_rank: Super Contributor
timestamp: February 13, 2025, 05:03:01 am
content: Be aware that if you don't have any mask then you can't have any silk either because silk can only be applied on top of mask.Using yellow mask will allow silk as usual.

author: Kasper
author_rank: Frequent Contributor
timestamp: February 13, 2025, 05:12:20 am
content: FAFO: add a soldermask layer, draw on it, load it into JLC and use their preview to see what it looks like. Don't even need to order boards to preview.If you want to show off, make business cards, coasters or ...For business cards, I use black soldermask and ENIG. Text typed in soldermask layer.You get a black card with gold lettering.

author: bostonman
author_rank: Super Contributor
timestamp: February 13, 2025, 01:34:20 pm
content: QuoteWas a solder mask used in the older days? For some reason I remember seeing boards without solder masks. If so, were silk screens used back then?

author: Kasper
author_rank: Frequent Contributor
timestamp: February 13, 2025, 03:10:13 pm
content: 10 years ago, I would order PCBs from Alberta Printed Circuits in Canada. They'd charge extra for:More than 2 PCBsSoldermaskSilkscreenDrills that weren't from their list of about 10 sizes. Smallest being 0.43mm, I think.For small boards, a few sq inches, I think it was about $50 to $100 CAD/USD for 2 plus $25 for shipping.That was a very low price compared to other higher end fabs I'd use near Vancouver.