Why does SMT 0805 footprint look strange in JLC gerber preview?

I’m working on my first board with Kicad, and have it ready to submit to JLC for fab.
In the JLC Gerber viewer, the pads on R1, R2, R3 look odd - it’s like the solder mask is extending into the pad area?

In pcbnew, it looks like this

It also looks OK in the Kicad gerber viewer:

I generated the Gerber and Drill files according to the instructions on JLC.

I’ve seen this before. It’s a bug.

A bug in Kicad or in JLC’s system?

If Kicad, is there a workaround?

It also affects the SOIC18 footprint:

JLC. It’s fine in other viewers.

So I should send it somewhere else for fab. Who do you recommend?

Or, are you saying that it is only in the JLC viewer, and the fabricated boards would be correct?

It’s a problem with their viewer.

The is one of the best online viewers out there:


Pretty sure its there veiwer not knowing how to handle rounded rectangle pads, it seems like they are drawing the rectangular pad, then subtracting the ovals, where it should only be subtracting the corners.

Raise it with JLC and have them look at fixing there bug,

And there seems to be a second bug for the silk of the jumper.

JLC confirms it is bug in their viewer, and pads and silkscreen will be per the Kicad gerber viewer.


Hi. I have the same issue with JLCPCB gerber viewer. What version of Kicad do you use?
I’ve used 5.99 nightly and have the same problem with SMD resistor layouts. Also I tried to export gerbers from one of my old project made with 5.1.2 version and there is no problem. After that I tried with the same project and exported gerbers via 5.99 nightly and there I reproduce problem again. Also with gerbers exported from 5.99 version some of online gerber viewers can’t read them all. With OSHPark there is no problem. In 5.99 there is something changed in gerber export but I don’t know what is it.

I think, as @Rerouter pointed out, this is a problem with rounded rectangles - which were only introduced as standard in the KiCad library in a fairly recent version - can’t recall which one.

There never were normal rectangle pads for R, C or L standard sizes in the library for version 5 (the rounded rectangles were introduced while we created the library for v5. So at the latest with 5.0.0-rc2 as that was kind of the feature freeze for the library.)

So it is safe to order my PCB from JLPCB and ignore their gerber viewer?
In PCB preview on website is rendered normal. Top image is from preview.

Nobody here will give you a gurantee. So I suggest you do your own research and possibly contact your manufacturer.

I’ve seen a few issues with their gerber viewer. Another one is the silkscreen for the chip notch is the wrong way around.

Received the PCB’s last week and no issues, so its only their viewer. But if you wan’t to be 100% sure then email support@jlcpcb.com

Screenshot from 2020-07-13 12-38-54

Thanks I will contact with them.

Maybe if enough people keep asking the same question of support, they might install a better viewer. It’s really puzzling why a large fab like them keeps using a viewer with bugs, when there are open source viewers like tracespace.io under MIT license, which has already been adopted by at least a couple of fabs I know of.

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