2023-12-28

Ordering PCBs

Ordering PCBs and assembly is fun :-)

Well, not fun, and to be honest, one of the biggest challenges is the parts selection, what they have in stock or something equivalent, but designing the PCB is definitely fun (well, for me).

I export a gerber files that are the instructions to make the PCB tracking images, and also a BOM (bill of materials) and position file, for placing the parts.

I have done this many many times with several PCB manufacturers, and lately with JLCPCB, which seem to be surprisingly quick and sensibly priced (apart from the odd quirk). I'd love to find a UK company as cheap and easy to use, I'd use them.

The PCB printing has a few design constraints, the gaps between tracks, minimum track width, and so on, which relate to the optics of the process for printing and drilling the board itself. But apart from that the PCB is printed exactly as expected.

Well, until now.

This is what I ordered... (this is an image from their order history page)

And this is what arrived...

It took me ages to debug it - tracking down that the CPU was running way too hot (burned my finger) and not quite right. It turned out it was running on 4.5V not 3.3V. The shorts there short input to output on a regulator circuit and I was testing from 5V USB via a diode. If I had tested 12V it would have made smoke, I expect.

The thing is the order process involves a lot of steps, and each step show the PCB you are making.

  • When uploading the gerber files
  • When selecting assembly and it shows the bare PCB
  • When showing PCB with parts
  • When order complete and preview of PCB
  • When order complete and preview of assembly
  • On gerber viewer on the site from their order confirmation

At every stage they show the circuit correctly, but the final PCB was faulty.

I complained, and they advised: "We have reflected this issue to our engineering team and JLCCAM software team and they have found and fixed the issue just now, and there will be no the same issue next time, so don't worry about it."

They even provided an image of the error:

Next step - refund!

My view is simple.

  • They made an error in printing the PCB.
  • Arguably they made an error with the flying lead test of the PCB not spotting the printing error.
  • They then made the PCB with parts that cost money - either of the above errors not made would have avoided that.
  • It was not, in any way, my fault.
  • I did not get what I paid for.

It is simple. I should not only have a full refund, including shipping cost, but ideally I should be compensated for the hours of debug, the delay in getting working boards, and the cost of disposing of the WEEE (defunct PCBs and part).

I'll be happy for just a full refund, and either they pay for courier to return boards, or I dispose of them (at my cost). As I buy loads from them, I'd even allow for it to be a credit on my account rather than an actual refund.

I have a funny feeling they will try and weasel out of this - and then I may have to ask Amex to intervene. It is for two separate batches of boards (from 4 I ordered, 2 of which were fine) totalling over $470.

Watch this space - I'll update with news.

Update: They do seem to be trying to weasel out of out - that PCB manufacturer is separate from supplying parts and assembly - but the parts they supplied are useless to me as supplied, so not reasonable that I pay for them, surely? Indeed, I have offered to send the parts back to them (at their cost). We'll see how that goes.

They suggested I try and isolate the track, but this is cutting through soldered pads, so when I put the components back it will short again!

Update: They are being counter reasonable. I suggested I could maybe find someone to rework - they suggested I try, and get a quote. I may try and get a quote.

They also think just cleaning solder would be enough to avoid shorting with the component leads when cut like this...

Update: I have decided instead to offer a compromise on basis that on one board I can re-use the SCD41 sensors they have supplied. Pushing their offer $50 more on each set of boards. We'll see.

Update: We have credits now.

8 comments:

  1. Why not updated/fixed boards to replace the faulty ones?

    ReplyDelete
    Replies
    1. I think the suggestion is that they send out new fully assembled PCBs.

      Delete
  2. Is it a 2 or 4 layer PCB? If 2 layers then maybe it would be worth investing in a PCB router and make your own PCB's. Prices & capabilities vary. Would still need to do the assembly

    ReplyDelete
    Replies
    1. Been there, done that, and indeed, for some circuits it provides a way quicker turnaround, but is somewhat limiting for components which need a solder mask and stencil. I have seem some impressive kit people use, even printing solder paste, but with a turnaround of about a week including assembly, this is easier.

      Delete
  3. I certainly see where you're coming from.

    ...and I also see why they would want to minimise the amount they have to compensate you.

    As a professional/development service it's common for both sides to negotiate, as you have done. Especially where "trivial" mistakes have such a massive knock-on effect.

    On the one hand, as a regular consumer I'd expect better because there would be no assumption that I was technical capable.
    On the other, as a professional relationship, I'd expect them to be accommodating and want to do as much for the customer as possible.

    Their suggestion for rework seems reasonable, especially on a 2 layer board.

    I'd also be very amenable to rework if it was a short run that I was planning to do another iteration of: most of the value of these services is in time, not money, so rework would usually be the shortest time-path to the next stage of your development.

    Even in production work, when things go wrong that need lots of expensive rework on lots of board, there is usually a negotiation to reduce waste and start-from-scratch scenarios.


    If I was doing it and was worried about the solder bridging then I would also probably cut the tracks at the places between the pins and then add in a new wire instead of the incorrectly placed track.


    Good luck!

    ReplyDelete
    Replies
    1. PS: I'm also happy to help you with the rework if that would be useful.

      Delete
    2. We have managed to negotiate a reasonable amount on the basis that I can, reasonably easily with a heat gun, reuse the expensive part (SCD41).

      Delete
  4. I have to say, if I were in the same position, 'reworking' the board in this way would have been equally unacceptable.

    ReplyDelete

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