I made a simple breakout board for a sensor using this tutorial:
The board only has a few components on 1 side. So, the back solder mask appears empty (the file is ~500 bytes). I sent it off to JLCPCB but they replied that there is an issue with the board:
"Tks for your pcb order on our website, pls help advise below issue before proceeding by tomorrow latest ,tks .
Noticed there wasn’t solder mask on bottom copper layer based on your design ,is it correct and can we proceed for production as it ?"
I changed the board setup to be a 1 sided board (so the back Gerber files are not produced) and sent it again and told them it is 1 sided. They rejected it again for the same reason. Per other discussions, I told them to just put mask on the whole bottom side and they said no, to fix it on my side and send it again.
I do not know what else to do. I am new to PCB layouts and KiCad.
I see @Danchik had basically the same issue one this thread: Applying a solder mask to the board but no resolution is given there. Does anyone have any ideas? I can send it to another board shop but the $2 JLCPCB price is hard to beat.
If you use THT components - as can be seen in the that “KiCAD Quick-Start” still image - the back solder mask isn’t empty. You should create a normal 2-layer board and have graphics in the bottom solder mask layer where the through hole pads are. I can see zero reasons to not apply the solder mask to the backside of the board at all.
If you use the standard KiCad footprints for the components there shouldn’t be any problems. The correct bottom layers are exported correctly to gerbers if you choose them.
You can also give us the whole project and someone can check if there’s something fundamentally wrong there. If you do that, keep the gerbers which you generated with the project.
Thanks for your reply. I am using SMD parts. When I try to upload my project, I get a message saying that new users can’t upload attachments. I will try again after this reply.
OK, I don’t see anything wrong with the project or the gerbers. To be honest I don’t understand why the manufacturers aren’t sure what to do with empty B.Mask layer. With one quick glance it looks self-evident that there are no pads on the bottom side and the mask substance should be applied to the whole backside.
Use their preferred method of giving notes and tell them something like this:
“There are no mask openings in the back side, therefore the B.Mask gerber layer is empty. Please apply the mask to the whole backside of the board.”
If they don’t understand that, tell them they are stupid. Because that would be true.
You can of course put some “fake” graphics there. For example draw lines along the edge of the board so that there will be narrow non-masked edge in the physical board. Or write your board name and revision number there in the mask layer (looks nice on top of a copper fill) if small amount of exposed copper isn’t a problem. Or write text outside the board outlines saying “Back mask layer intentionally left blank. Apply mask to the whole backside.”
I have never ordered anything in JLC.
I didn’t look into your project, but do you have any cooper at bottom. If no then may be when you fill the whole bottom with copper then they will have no problems with solder mask on it.
When you tried to tell them that it is one side pcb that may be they had the problem as standard one side PCB has tracks at bottom and not top. I am just trying to find any possibility assuming they are more stupid than I probably should assume.
I appreciate the replies. I will try to put some lines and such on the bottom, with a note, and send it over email and post any reply.
The board does have a copper zone in the bottom (and the bottom copper Gerber appears not empty). I did not know that 1 sided PCBs have tracks at the bottom, thanks for the info.
So I put lines around the back and some text in the b mask and covered the text with silkscreen text – then I sent them the zip file and asked them if it passes their checks.
"Roughly , your attached need to improved i think ,since no trace and copper layer ？ also without anything on bottom solder mask layer ,that means cover by solder mask ink ?
Pls, can you ask someone for help on your side in case of more rejection"
One side PCBs can have tracks at top or bottom, but a standard (historically) one side is TH elements on top, and connections on bottom (it is easier to solder, not only manually, but also by machine - wave soldering).
I have many times designed two side PCBs with all elements at bottom and GND plane at top (I just prefere to see PCB in the same orientation as user sees the device case - if I put LEDs (at top) at left they are at left and not right if I had designed PCB reversally) and had never problems ordering such PCBs. But as I remember I have never ordered one side PCB with tracks at top.
But as I said - I was just looking for any posiibility of source of their problems.
This also had a problem with the bottom mask layer so I used it to play around and found out that if I select “Do not tent vias” the bottom solder mask renders as expected. So I went back to JLCPCB and they are now complaining about some naming issues – at least it is not the solder mask.
Not sure what are you speaking about but if about what I have written that all elements at bottom then you shold know that assembling need not to be done in the same orientation then designing.
I just help myself to avoid a mistake when transferring for example LED positions to mechanical drawing with openings for them.
I’ve had similar issues submitting single sided boards to JLCPCB. I used the “two layers, parts on Front only” layer setup in Pcbnew. But when I submitted to JLCPCB they asked a confusing question about what to do with the bottom mask.
They gave two options: "1) to cover it all with tin 2) to cover it all with solder mask. ". We selected option 2 and all was well, but to avoid the drama in the future we no longer use that layer setup. Instead we always design with a bottom mask, even if it is empty.
It sounds like you got caught by something similar, but in addition there are some issues with the gerbers you’ve submitted.
In general, make sure you generate and send the front and back Cu, Paste, SilkS and Mask layers, plus the Edge.Cuts. A line width of 0.15mm, coordinate format 4.6, and including X2 attributes works for us. We’ve submitted dozens of designs to JLCPCB and rarely have issues, so this issue stood out.
JLCPCB’s online preview is very good - after uploading your gerbers, check the output of the online checker and review the preview carefully before submitting.
I do NOT trust fabrication houses in China to keep designs secure; something to think about.
OSHPark is USA located company and has a privacy policy ( I have no affiliation with OSHPark other than as a happy paying customer ).
OSHPark also accepts both native KiCad files and Gerbers for projects; and performs online reviews of both file systems. There is no cost for these reviews.
I’d upload your files to OSHPark in both formats and see if there is some way to determine exactly who/what/where/when is to blame for JLCPCB’s reject status of your project.
Not to try to steer customers away from OSHPark, I like them and use them often, but if you want soldermask color other than purple you will have to buy elsewhere. If you want to get a good handle on the cost from several manufacturers at once, check out PCB Shopper. You enter in some basic details for your board (size, number of layers, quantity desired, mask and silk colors, etc) and get rough quotes from 25 different manufacturers. Obviously they don’t generate quotes for all the available board manufacturers, but there are some good names in their list.
However, the main point was that OSHPark accepts both native KiCad and Gerber file formats and does a fairly good Design Check as part of the upload process; a process that can be used to troubleshoot potential Gerber generation issues.
One other reason why I have been using OSHPark is how well the boards end up being exactly as the files contents are. In my experience, if there is something wrong with a delivered board, there is a problem in the design file, and not the service. In my opinion this is very valuable in learning how to use KiCad to get a physical board exactly 100% as intended.
And, the final reason they are my favorite for proto-boards is because it avoids all the potential hassles of China shipping.
But certainly, if a design required a specific soldermask color (other than purple), I’d have to use another vendor.
