Selecting Components For PCB Assembly??

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rstew
Posts: 7
Joined: 28 Sep 2021, 18:25

Selecting Components For PCB Assembly??

#1 Post by rstew » 28 Sep 2021, 18:43

Hi All;
New to this forum, but I have been using DipTrace for well over 2 years and have ordered many bare boards from both Domestic North American and Asian sources.
Now I want to try ordering some completely assembled boards, in this case with only a few components, mostly SMT and a couple of thru-hole.
In DipTrace I have the components identified with the manufacturers PN's and Digikey PN's.
I created and sent the BOM and the CPL to JLCPCB, only to find they can't correlate the PN's to parts they have in stock.
It appears you have to wade through their component inventory and select equivalent parts by their PN's. What a pain!
Is there a board house in China or elsewhere that can correlate domestic component PN's automatically?
Any other ideas? There has to be a way to do this but I don't know where to look.

Thanks,
rstew

Alex
Technical Support
Posts: 3626
Joined: 14 Jun 2010, 06:43

Re: Selecting Components For PCB Assembly??

#2 Post by Alex » 29 Sep 2021, 05:07

Try to load BOM to https://lcsc.com/bom . I have never used it but maybe some equivalents can be found automatically.

charlesR
Posts: 8
Joined: 04 Jan 2021, 23:09

Re: Selecting Components For PCB Assembly??

#3 Post by charlesR » 04 Oct 2021, 17:07

I have used JLCPCB's SMD assembly service many times and I have had very good luck. For me, the most difficult step is: "How to find the parts I need, and what is the part number that JLCPCB will accept as valid?" I have found 3 options.

1. Use https://lcsc.com/bom as suggested by Alex

2. Download JLCPCB's Excel file which contains all parts (https://jlcpcb.com/componentSearch/uploadComponentInfo, then open up Excel file and use "data filters" and "pivot tables" to search for the components you need. I find this is the fastest way to narrow down my search to specific parts like "resistors, capacitors, linear regulators, etc", however it contains very limited info on electrical characteristics of the individual components. If you need this detail, then try Option 3 below.

3. This kind gentlemen: (Jan Mrázek) has developed a parametric search tool specifically for JLCPCB to try and solve this problem. Link is here: https://github.com/yaqwsx/jlcparts It's a fairly big improvement versus the search tool on JLCPCB website and LCSC website, but it takes some time to learn how to use it. Just fair warning: this parametric tool is also not as powerful as the parametric search tool like you might find on Digikey's website, but it's better than nothing.

Most of my BOM's contain about 15 to 30 parts depending on the project- and it takes me a solid 4 or 5 hours just to properly populate my CPL and BOM files. This is huge time sink and brings no joy. However I also get no joy out of assembling the PCB's myself with 0403 sized parts!

Here is similar post I made on Diptrace forum that might help you also
viewtopic.php?f=4&t=13779&p=29731&hilit=cpl#p29731

Good luck
Charles

rstew
Posts: 7
Joined: 28 Sep 2021, 18:25

Re: Selecting Components For PCB Assembly??

#4 Post by rstew » 09 Oct 2021, 22:04

Thanks Alex and Charles. I will check out those options and see how it goes.\

rstew

rstew
Posts: 7
Joined: 28 Sep 2021, 18:25

Re: Selecting Components For PCB Assembly??

#5 Post by rstew » 09 Oct 2021, 22:46

Charles, I just reviewed your earlier post that you referenced above, and it has some great advice. I wish I had known some of that earlier; it would have saved a lot of frustration and grief.
It's too bad JLC don't incorporate a basic introductory type file that contains some of that kind of information. That would help a newbie get past the initial hurdles and roadblocks and enhance their assembly business I would think.
Actually if they would just update their tutorial to reflect the required format for the BOM and CPL, that would be a big help also.
Just my nickles worth.

rstew

rstew
Posts: 7
Joined: 28 Sep 2021, 18:25

Re: Selecting Components For PCB Assembly??

#6 Post by rstew » 10 Oct 2021, 13:54

Another thing about ordering assembled boards is it seems like the default quantity limit is 50 boards. I would like to order 200 or so, but there does not seem to be a way to do that.
I have sent a request through their chat line, but of course its the weekend and I guess no one is around to answer my question. Hopefully this week.
Anyone know how you go about ordering a bigger quantity?

rstew

charlesR
Posts: 8
Joined: 04 Jan 2021, 23:09

Re: Selecting Components For PCB Assembly??

#7 Post by charlesR » 22 Oct 2021, 20:45

rstew wrote:
10 Oct 2021, 13:54
Another thing about ordering assembled boards is it seems like the default quantity limit is 50 boards. I would like to order 200 or so, but there does not seem to be a way to do that.
I have sent a request through their chat line, but of course its the weekend and I guess no one is around to answer my question. Hopefully this week.
Anyone know how you go about ordering a bigger quantity?

rstew
Hi rstew,
You are correct- JLCPCB's SMT Assembly service maximum order size is 50 boards. The best way to get more boards is to use Diptrace's PCB Layout to Panelize your board. Select "Edit \ Panelizing" from the main menu to open the dialog box. Diptrace made a video about this here... viewtopic.php?t=14087#p30648

The maximum single panel size for JLCPCB is:
· 2 Layer: 20x20mm - 480x320mm
· 4&6 Layer: 20x20mm - 350x320mm

So assuming you have a 2 Layer PCB, and your PCB is smaller than the JLCPCB maximum dimensions above, then you simply create multiple copies of your PCB and Diptrace "fits" them into a single board. For example, if your board is 50mmx50mm then you should be able to get 50 PCB's on a single board, and then order 5 boards = 250 PCB's.

To separate individual PCB's from panel, you can use V-score or "mouse-bite" methods. Or you can just use special scissors (snips) that cut through metal like these... ($35 USD)

https://www.amazon.com/Malco-M12A-12-In ... EBW2&psc=1

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