Kicad vs JLCPCB assembly (small parts)

Hi everyone,

I want to design a layout with small addressable rgb leds (ws2812b-2020) and have JLCPCB make the assembly

are there special considerations in that matter ? are they gonna make it happen just like that no matter what I design ?

I usually solder everything myself, so this is new ground for me

thanks for your insights

No problem. 2020 package is huge to their technology. I used them for WS2812B 1615 package and all was good. Passive components down to 0402. No problems whatsoever.
Just make sure that the LEDs are not rotated.

how do you mean “not rotated” ? why would’nt be allowed to rotate a package ?
and in respect to what axis ?? this is confusing to say the least :slight_smile:

Sometimes KiCAD exports CPL with with a wrong part rotation, so while you place check on the preview that they are all as per your design.
Usually if your KiCAD footpritnt has the same rotation as their footprint on the components page then it’s fine.
They have two of these diodes: C965555 and C5349955.
One footprint has pin #1 top left, the other is bottom right (rotated 180 deg).
To make it easy - rotate your footprint to have the same orientation. Alternatively you can rotated later manually after the CPL file is exported.

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I downloaded the ezlib from jlcpcb site, I guess it should be fine as long as I dont modify their footprint

Possibly. I’ve never used their footprints. Very inconsistent.
I always use either KiCAD libs or make my own.
However in this case at least the rotation will be correct.

really ? they can’t be trusted ? I noticed, back in the day, many different online pinouts, for ws8212 leds, for instance, a pain in the ass
I always buy a couple of them to try them before designing anything

Find the correct JLC part number, make sure the footprint is available for download (from EasyEDA), download the footprint (there’s a KiCad add-on/plugin for that). Never had any problems with that.
Regarding rotation: I never bothered with that. It is always seemingly random (it is not, 0° refers to the orientation the part is located in the tape, which might be different from the footprint orientation), but a JLC engineer will fix it for you IF you provide a clear polarity orientation somewhere (e.g. in the silkscreen).

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Agree that there is no need to worry about rotation as they are quite alert to catching it. You should also check the box at jlc order time that says something to the effect of “require confirmation.” Then the job will not proceed until you approve a placement file like this one (white dots are my silk and red dots are jlc placement, and there are red +/- marks on diodes etc):


When the job is initailly submitted you may see a pic like this with an incorrect part rotation (or 10) – don’t worry as that is before their engineer peeks at it and corrects it. When you get the approval drawing it is usually correct, but you have a chance to correct anything they missed or misinterpreted.

They have also fixed a part of mine that needed x/y translation (an sd card that had the centroid in the wrong spot).

Yes, forgot to mention - as long as it is remotely clear where and how your component should belong, a JLC engineer will fix it. I have never bothered changing footprint reference point or rotation.

They will also happily place a 0603 component on a 0402 footprint! I’d say if your component does not fall off when you turn the PCB upside down after soldering, JLC will accept it and make it work.

BTW this is in stark contrast to Eurocircuits - they will complain with the slightest mismatch. They have found a handful of bugs for me (also details with slightly wrong part number) that slipped through, which is great - but is sometimes a pain to get a design through, particularly if you are in a hurry. Unfortunately EC is far too expensive for personal use.

alrighty then, thanks everyone !!

In my experience PCBWay is very careful with parts orientation. I used a SMT side-view LED that only had one possible orientation that matched the silkscreen, and they still asked for confirmation that it was correct…

I like JLC as it’s one stop shop for PCB manufacturing, parts sourcing and assembly (if you are OK with they parts stock).
I used PCBWay for PCB manufacturing before, but not for PCBA as souring the parts seems slow and complex. That’s my feeling when I read about it.
May try them in a future.