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Forum Index : Microcontroller and PC projects : JLCPCB standards dropping?
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bigmik Guru  Joined: 20/06/2011 Location: AustraliaPosts: 2914 |
G’day all, This is a question not a statement. Is JLC dropping the ball a bit lately? Especially with their PCBA? It appears that quite a few people are getting 1 dud assembled board out of 5 purchased. I recently received a set of PCBs and they were packaged differently than usual, normally they are in a vacuum sealed bubble wrap type bag these were wrapped in paper inside a “less” vacuum sealed bag. My PCBs seem fine but I noticed a different packaging method. I think they might be rationalising their methods a bit and possibly errors are creeping in. Interested in others thoughts on this. Regards Mick Mick's uMite Stuff can be found >>> HERE (Kindly hosted by Dontronics) <<< |
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| Amnesie Guru Joined: 30/06/2020 Location: GermanyPosts: 396 |
Yepp, same here. As you mentioned. With my latest order there was no problem, but with the last TWO (!) (scratches & defective traces all along)... Who knows whats wrong there... Greetings Daniel |
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| bigmik Guru Joined: 20/06/2011 Location: AustraliaPosts: 2914 |
Thanks Daniel, This is a worrying trend. Regards, Mick Mick's uMite Stuff can be found >>> HERE (Kindly hosted by Dontronics) <<< |
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Mixtel90 Guru Joined: 05/10/2019 Location: United KingdomPosts: 6786 |
I'll see what my current order is like - they've currently in transit. They aren't assembled though, just some aquarium controller boards. I wouldn't expect them to do functional testing of assembled boards. They have no schematic for a start. If pick & place is a bit off and causes a bad solder joint then they aren't going to find it. The boards prior to assembly should be OK though as they do point-to-point testing as standard, I think.. Mick Zilog Inside! nascom.info for Nascom & Gemini Preliminary MMBasic docs & my PCB designs |
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| bigmik Guru Joined: 20/06/2011 Location: AustraliaPosts: 2914 |
G’day All, I have personally never had a bad board from JLC, well one that was their doing, plenty that were my stuff ups. I have been considering getting a board done in PCBA but the recent faults have me concerned, and Daniel said his bare boards were scratched and had traces that were not where they should have been. Regards Mick (the big one) Mick's uMite Stuff can be found >>> HERE (Kindly hosted by Dontronics) <<< |
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| Mixtel90 Guru Joined: 05/10/2019 Location: United KingdomPosts: 6786 |
Personally I've never had a bad board from them and the sealed bubble-wrap and plastic wrapping has kept them in mint condition as far as the UK. :) Mick Zilog Inside! nascom.info for Nascom & Gemini Preliminary MMBasic docs & my PCB designs |
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Grogster Admin Group  Joined: 31/12/2012 Location: New ZealandPosts: 9306 |
As far as their PCB's are concerned, they are excellent.  Very cheap also. As far as the PCBA, I got one CMM2G2 board recently, which had solder-bridges on some of the pins(two bridges in two places from memory), but I fixed the board by simply reflowing the ARM chip in the area of the bridges, and checking again under my microscope. One CMM2G2 board I got(a different one to that mentioned above), had bad solder work on the SDRAM chip, and I was getting errors at boot-up time. I fixed that one also, by just manually reflowing all the pins on the SDRAM chip. But yeah........not sure what to think at this point. I do hear what Mick(not the big one!) is saying, and it would be totally unrealistic to expect them to check every SMD connection they do, but generally speaking, the SMD assembly process is pretty reliable now, and you don't NORMALLY hear of any problems, and the PCBA process can often be better then some people's manual soldering, so..... It's a bit difficult to know. Smoke makes things work. When the smoke gets out, it stops! |
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| JohnS Guru Joined: 18/11/2011 Location: United KingdomPosts: 3801 |
I'm another who had 1 bad out of 5. Still works out a good price. John |
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| Volhout Guru Joined: 05/03/2018 Location: NetherlandsPosts: 4233 |
John, In my employers soldering streets (yep...long production lines....streets) the reflow (temperature) profile is tuned to the product. Sample runs are done on a product and soldering is inspected both AI and human visual. In case there are large differences in heat capacity (i.e. small 0402's next to large connectors or capacitors or inductors) local temperatures are measured with thermocouples during soldering. This is labor intensive, and creates waste. When JLC build only few samples, that "tuning" is not performed, and they must run a default temperture profile. The (max) 10x10cm boards are so cheap, that they where most likely in spare area of larger production series. In that case you are depending on the temperature profile of the larger series. All in all, I am not surprized there are occasional soldering problems. Regards, Volhout PicomiteVGA PETSCII ROBOTS |
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| JohnS Guru Joined: 18/11/2011 Location: United KingdomPosts: 3801 |
Thanks for the explanation - seems highly plausible. John |
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| Grogster Admin Group Joined: 31/12/2012 Location: New ZealandPosts: 9306 |
Yes, I agree when put like that. I also must mention, that prior to the virus and the silicon chip shortages that created, I never had a single faulty CMM2G2 board from JLC, and they must have made me hundreds of those during the time I was selling them. In other words, I will still be using JLC for my next PCBA order. The issues - for whatever reason - have not made be go elsewhere, and there are A-LOT of PCB houses in China to choose from!  Smoke makes things work. When the smoke gets out, it stops! |
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