Tearing my hair out with a Chinese PCB company - Page 1
Forum section: electronics / general

author: peter-h
author_rank: Super Contributor
timestamp: October 25, 2021, 05:01:11 pm
content: I've been buying a panel, 32 circuits on it, for many years.The last company, China, ran for ~ 5 years and then vanished.I found another. I sent them the gerber data, and for avoidance of any doubt I sent them by DHL a panel of the existing (production/assembly tested) board.The idea is that they test the existing sample panel against the gerber data, to make sure there is no mis-interpretation of the data.But they didn't get this at all.After many emails, dealing with poor English, I agreed to pay USD 200 for them to make 1 panel from my gerber. They could then test that panel, and immediately test my sample panel, and if they both pass then obviously the two panels are electrically identicalNo joy...3 months and many emails later, no progress. It sort of appears that their panel probably does test ok. But they just don't get the principle of testing both panels to the same data.Is there some other interpretation on this saga?

author: mc172
author_rank: Frequent Contributor
timestamp: October 25, 2021, 05:21:49 pm
content: Can you get them to send you back your original sample and a production sample and test them yourself?

author: thinkfat
author_rank: Unknown
timestamp: October 25, 2021, 05:31:45 pm
content: That's a tedious process. It'd be much easier if they ran both panels through their flying probes machine.But this ordeal has only one conclusion: you cannot possibly work with this manufacturer.

author: ataradov
author_rank: Super Contributor
timestamp: October 25, 2021, 05:33:28 pm
content: Why would they bother testing your other board? I don't think this is a typical request, and that's why they are probably confused.You send gerbers, they send you the boards that match those gerbers. Why there needs to be another board involved?And also, let's say they don't match, what do you want them to do? They can't be responsible for some third-party board.

author: mc172
author_rank: Frequent Contributor
timestamp: October 25, 2021, 06:33:58 pm
content: Quote from: thinkfat on October 25, 2021, 05:31:45 pmNot really, you just build one!

author: peter-h
author_rank: Super Contributor
timestamp: October 25, 2021, 07:29:30 pm
content: There are various misinterpretations of gerber data possible, for example if there are tracks within planes. Yes, I know those should be done as polygon pours...What I don't get is why they don't seem to understand the instruction. It is absolutely trivial. Just test their panel and immediately test my panel.If they don't match then I have to abandon this order.Populating a board is not a full test. There could be open circuits, etc.

author: james_s
author_rank: Super Contributor
timestamp: October 25, 2021, 07:32:22 pm
content: I've never heard of someone sending a finished board to a PCB fab. You just have a minimal order made, then when you receive the sample order you evaluate the board yourself. It is not reasonable to expect them to set up and test a board they didn't make.

author: langwadt
author_rank: Super Contributor
timestamp: October 25, 2021, 07:44:16 pm
content: Quote from: peter-h on October 25, 2021, 05:01:11 pmif for some strange reason you don't think a pcb manufacturer can make pcbs from gerbers why do you think that they are capable ofmaking a test from the same gerbers that guarantee that they are "identical"?

author: mc172
author_rank: Frequent Contributor
timestamp: October 25, 2021, 07:52:03 pm
content: Quote from: peter-h on October 25, 2021, 07:29:30 pmI obviously didn't mean just put the components on and be done with it.You must have some sort of test procedure, fixture, etc., the outcome of which at some point must have convinced you that the boards from the original manufacturer were up to standard. So repeat that test with the new boards after populating one.

author: ataradov
author_rank: Super Contributor
timestamp: October 25, 2021, 08:13:04 pm
content: Quote from: peter-h on October 25, 2021, 07:29:30 pmOn a gerber level it does not matter. All planes would be broken up at the time gerber is generated. Your gerbers need to be very bad to be misinterpreted with modern tools.Quote from: peter-h on October 25, 2021, 07:29:30 pmThat sound like you want them to do extra work with no obvious benefit to them. Unless it is a very big order, I would not bother either.

author: NorthGuy
author_rank: Super Contributor
timestamp: October 25, 2021, 08:30:46 pm
content: What you ask them to do is totally unreasonable. You want them to build boards using your gerbers, then if the result doesn't match the test board (which they have no control over) you want them to throw their work away and return you the money. They probably didn't understand what you're asking, because nobody in the right mind would ever agree to such conditions.You probably can hire someone to test your board and see if the garbers match the board, but I would guess such job might cost more than manufacturing few PCBs. Even if your test board passes the fly test designed for the gerber, there's no guarantee that boards made with the gerber are identical to the test board. For example, some of the features of your test board might not be in the gerbers, not to mention possible SI differences.

author: peter-h
author_rank: Super Contributor
timestamp: October 25, 2021, 08:49:42 pm
content: "What you ask them to do is totally unreasonable. You want them to build boards using your gerbers, then if the result doesn't match the test board (which they have no control over) you want them to throw their work away and return you the money. They probably didn't understand what you're asking, because nobody in the right mind would ever agree to such conditions."Whole load of totally wrong assumptions there, but hey this is social mediaI paid for the "tooling" plus the cost of making the one board. I merely asked them, when they BBT the panel they made, toalso BBT the panel I sent them. Extra labour = seconds. If the two don't match, then there is a problem, I lose the NRE charges plus the panel cost, but detecting that is better than getting a few k boards back, populating them, and finding they don't work.Many years ago I got a few k boards back from a UK company. BBT passed of course. Populated them all. First one tested blew up the PSU. Turned out that all the vias were plated to all the inner layersYes this is rare nowadays, but the risk is very high. Especially when one has struggled buying the various chips at extortionate prices of today, and even then managed to get only just enough.I have used this process for 100% board validation before, and never had a problem.The reason I posted this was not to get sympathyit was to find out whether there is some issue with BBT which prevents two panels being tested from the same data. Of course I can't see how that could be possible. I am 99% sure these people just struggle to google translate between Chinese and English.

author: ataradov
author_rank: Super Contributor
timestamp: October 25, 2021, 09:18:25 pm
content: The deal is that you send gerbers, they send you board that match those gerbers. Why would they do anything extra? It is not seconds, it is never seconds. No vendor in their right mind will do what you want. This opens up so much liability that it is not worth it.

author: thm_w
author_rank: Super Contributor
timestamp: October 25, 2021, 09:20:23 pm
content: If all the vias were plated to inner layers, then the flying probe test would not pass. Either they lied or they tested based on their bad import, or there is some other information you are leaving out.They can just lie and say "yes it matches your board" and you will be in the exact same situation here.You should build up 1-10 boards and see if they work, before building 1000. And if you can't trust them to be making decent quality PCBs, you shouldn't be using them in the first place.

author: james_s
author_rank: Super Contributor
timestamp: October 25, 2021, 09:21:36 pm
content: Bottom line is modern PCB fab houses work a certain way. Either follow the standard procedure or you're going to have problems. It doesn't really matter how difficult or easy it is to do things your way, that isn't the way they work. I'm confused by what you're trying to get them to do and why so I'm not at all surprised that they're confused as well or don't want to waste time trying to work with you. They've got piles of other customers who just send them gerbers and don't try to get them to jump through extra hoops.

author: thm_w
author_rank: Super Contributor
timestamp: October 25, 2021, 09:24:36 pm
content: Quote from: james_s on October 25, 2021, 09:21:36 pmHe's done this in the past too. Expecting JLC to manufacture to his complex notes instead of just using industry standards:https://www.eevblog.com/forum/eda/jlpcb-having-an-interesting-attitude-to-reading-text-on-layers/

author: Mangozac
author_rank: Frequent Contributor
timestamp: October 25, 2021, 09:34:39 pm
content: Quote from: thm_w on October 25, 2021, 09:24:36 pmWow, that thread gives this one so much more context (and not to OP's benefit)!

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: October 26, 2021, 10:12:42 am
content: QuoteFor example, they may add tooling holes or other panelisation details that their process needs to load into their BBT system. It is quite possible that they make your panels as multiple images on a larger panel, so testing a single panel may be a fiddle, both mechanically and in dealing with the data.I really don't understand why you didn't just order a panel and test it. It's not like that is expensive these days.

author: thinkfat
author_rank: Unknown
timestamp: October 26, 2021, 10:33:33 am
content: Quote from: mc172 on October 25, 2021, 06:33:58 pmIt's not about just one. You'd have to build a whole panel of them and verify them all. I guess the OP tried to avoid the time and material to spend on this and thought of a quicker, more automated way to verify that the new panel is electrically identical to his reference. But as others have pointed out, it might not be as simple for the manufacturer as he thought.But what I pointed out is a different issue: How can you possibly work with a manufacturer that you cannot communicate with. It seems impossible for the OP to get across his request and just as impossible for the shop to explain why it won't work for them. I'm not doing finger pointing, I'm not calling anyones demands unreasonable, but clearly, this is not going to work for either of them.

author: peter-h
author_rank: Super Contributor
timestamp: October 26, 2021, 01:41:41 pm
content: When the character assasination squad is finished..."quicker, more automated way to verify that the new panel is electrically identical to his reference. "Exactly. Every other PCB company has done this previously. It is an easy way to ensure that you can go to a new PCB mfg and then go straight to production. The cost of a screwup on say 1000 PCBs is likely to be well into 5 digits."But as others have pointed out, it might not be as simple for the manufacturer as he thought."I struggle to see what is hard about- testing the panel they made- testing my reference panel right after thatMaybe they don't have in-house BBT? That would be weird, but not impossible. A lot of stuff is subcontracted down there."How can you possibly work with a manufacturer that you cannot communicate with."That is normal in China. Comms are often borderline. The typical Chinese scenario is a firm of say 100 people, and just 1 is educated in the West and he/she is their "voice" for all foreign customers.

author: free_electron
author_rank: Super Contributor
timestamp: October 26, 2021, 01:56:35 pm
content: Ever thought that their panel size may be different from yours ? They may simply have no way of mounting your panel in their tester.Your 'panel' may be a sub-panel for them. So what you supplied is smaller than what they run.Your data typically has stuff added : tooling , impedance and process control coupons and what not.Once the board has passed final testing then it is removed from its manufacturing panel. They typically do not reconfigure the tester for any arbitrary shape. the tester is set up for their fab panel size.

author: themadhippy
author_rank: Super Contributor
timestamp: October 26, 2021, 01:57:17 pm
content: QuoteHow many uk firms with a staff of 100 ,dealing with foreign customers have a member of staff fluent in mandarin or Cantonese ?

author: langwadt
author_rank: Super Contributor
timestamp: October 26, 2021, 02:17:59 pm
content: Quote from: peter-h on October 26, 2021, 01:41:41 pmsure if it someone doing manufacturing in a shed and testing is just some guy with a stack of pcbs he runs through a test manually. It is much more likely a highly automated (posssbly ISO certified) assembly line so what you want required stopping production to stick in your board, and that it assuming it will even fit

author: Kean
author_rank: Unknown
timestamp: October 26, 2021, 05:26:19 pm
content: As mikeselectricstuff and free_electron have pointed out, and from what I've seen myself of BBT machines in some factory tour videos, the BBT machines will often work with a larger production panel rather than a customer "sub-panel" for higher efficiency. Less manual handling.I actually had a video sent to me of testing a board produced for me. It had passed all BBT but had a shorts on an internal layer. It turned out they had a bug in their gerber processing tool for combining boards into production panels. The short was basically a line that ran right through the programming header, but only on some of the "sub-panels". Because the short was in the production panel gerber data, it passed testing. It was visible with back lighting, but annoyingly I'd already populated a few boards which failed before discovering it.

author: Mangozac
author_rank: Frequent Contributor
timestamp: October 27, 2021, 12:39:31 am
content: Quote from: mikeselectricstuff on October 26, 2021, 10:12:42 amExactly this. You order a prototype from JLC for $2. You build a sample and qualify it. When you're happy and want to order the production quality you go back to JLC and click "reorder" and enter in 100/1k/whatever quantity. That way you know that the same data has been used to fab both boards.

author: james_s
author_rank: Super Contributor
timestamp: October 27, 2021, 02:23:31 am
content: Nobody is trying to assassinate your character. We are just pointing out that you seem to have a history of trying to do things in a nonstandard way then having problems. The issue here is not them, it is you, or rather your peculiar workflow. Follow the standard workflow like everyone else does and you will stop having these problems.

author: peter-h
author_rank: Super Contributor
timestamp: October 27, 2021, 07:07:16 am
content: "When you're happy and want to order the production quality you go back to JLC and click "reorder" and enter in 100/1k/whatever quantity. That way you know that the same data has been used to fab both boards."JLC are too expensive for production work. Also, very limited ability to communicate in English. If you can't specify the job via the form on their website, it may come back "different". The other day I ordered 10 circuits and got back 10 panels of 10 circuitsClearly I did something "wrong", but this would never happen in conventional PCB purchasing where you specify the panel layout, overall panel size, breakout tab detail (with photos), etc."Nobody is trying to assassinate your character"Going back over somebody's old posts and digging up some other thread where that person got beaten up for something, is typical crappy social media behaviour. One sees it all over the place. Too many people with too much time on their hands... It's like you go on e.g. some snowboarding forum asking a question about snowboards, and a load of people dig up that you made a post in the off topic section, on brexit, and then beat you up, like a load of kids, in the snowboard section(I don't snowboard, btw).I don't think you and some others have even read my posts and the reasons for doing the BBT comparison. To say it yet again: it is to try to eliminate the risk of populating say 1000 boards (a 5 digit GBP figure) after a change of PCB manufacturer. I have been doing this routinely for many years.Anyway, this question is clearly not going to be answered. I was wondering if there was a BBT machine which somehow cannot test more than one board. I suspect this time that this company subcontracts the BBT and doesn't want to get involved, so is pretending they don't understand. It is a not uncommon Chinese tactic. They know that you will never turn up at their door.

author: ataradov
author_rank: Super Contributor
timestamp: October 27, 2021, 07:11:39 am
content: Why are you inventing crazy theories when there is a good explanation. This kind of behavior is exactly why they won't do your requests. Even if they do it and something does not work, you will come up with some theory to explain it, after all " It is a not uncommon Chinese tactic".

author: thinkfat
author_rank: Unknown
timestamp: October 27, 2021, 08:24:55 am
content: Quote from: Kean on October 26, 2021, 05:26:19 pmThat's a good example why it's prudent to verify boards before ordering in big quantities, even if the Gerber data is known-good. But also a caveat that even automated tests at the manufacturer might not save you.

author: thinkfat
author_rank: Unknown
timestamp: October 27, 2021, 08:36:43 am
content: Quote from: peter-h on October 27, 2021, 07:07:16 amOn the contrary, it has been answered. You're probably not getting the size of the operation you're dealing with. Maybe watch a video about JLCPCB's automated manufacturing line, Scotty from Strange Parts has done a tour of their facility a while ago, so go and check his Youtube channel. Then you might understand why what you ask is unreasonable for them.It might also be that the shop you're trying to contract is just an aggregator. They might not have any manufacturing capabilities themselves and thus simply cannot do what you ask for.

author: 48X24X48X
author_rank: Frequent Contributor
timestamp: October 27, 2021, 08:45:52 am
content: It is almost 100% that PCB companies will tweak your gerber to better suite their manufacturing capabilities. But, they are usually done in order to ensure it fits their manufacturing capabilities limits and also provide a better head room if possible. So, definitely PCB factory A and B will not manufacturer a 100% same exact output. But, having said that, it doesn't mean an assembled board from 2 different factories would give very different results unless you are doing some application that needing so much of accuracy and repetitiveness.But, JLCPCB is not expensive for their PCB (probably the cheapest) but maybe not an optimized option for assembly especially if your parts are not in their inventory. But, if you can only use their parts in your design and not looking for big volume or requiring full turnkey solution like testing, packing, etc, it is a good option. I have only tried them once for fun but for real production I used other service provider in Shenzhen.

author: thm_w
author_rank: Super Contributor
timestamp: October 27, 2021, 10:31:31 pm
content: Quote from: peter-h on October 27, 2021, 07:07:16 amI didn't "go over your old posts", I remember you posting about having issues with JLC. Which is incredibly relevant to this thread, as the problem isalmostthe same.I've also already recommended making a handful of pre-production units, to verify that their production process is correct, parts are good, etc.This way you are checking: the PCB, the pick and place, solder, the components, etc. Instead of just going overboard checking the PCB only, and assuming everything else will be good.

author: Mangozac
author_rank: Frequent Contributor
timestamp: October 27, 2021, 10:49:30 pm
content: Quote from: 48X24X48X on October 27, 2021, 08:45:52 amAnd for those concerned about such tweaks they do offer the "Confirm Production file" option when ordering.Quote from: peter-h on October 27, 2021, 07:07:16 amJLC have always come in the cheapest for any quotes I've done. Are you doing giant quantities or something?What are you doing that's so complex that you need to provide written instructions? When I design a board I specifically refer to the JLC design rules so that I can place the order without having to provide any further instructions. I understand that sometimes something more complex needs to be achieved; that's why you order just a couple of prototypes first and/or use the "confirm production file" option.The JLC order form provides plenty of guidance. Click on the question mark next to quantity and it specifically states "If your design is a panel with several boards on it, it is the number of your panels ..... When you place an order that requires us to panelize the board, it will be the number of panels. "

author: james_s
author_rank: Super Contributor
timestamp: October 27, 2021, 11:05:49 pm
content: Quote from: Mangozac on October 27, 2021, 10:49:30 pmFrom what I can tell, nothing. The issue isn't complexity, the issue is his unorthodox workflow and ignoring of standards and conventions that if followed, would negate the need to explain anything. I have never once had a board come out with an error that I didn't design into it myself. I've goofed up layouts a handful of times and it was always entirely my own fault, JLC and other providers manufactured the board exactly as I designed it.

author: langwadt
author_rank: Super Contributor
timestamp: October 28, 2021, 12:06:43 am
content: Quote from: james_s on October 27, 2021, 11:05:49 pmat the low price per board they must be making huge numbers every day, if they didn't have very high success rate they wouldn't be around for long

author: Matt-Brown
author_rank: Regular Contributor
timestamp: October 28, 2021, 03:19:59 pm
content: Asfter I have any of my customers panls made (I work for a contract manufacturing pcba house), we ask for the panelized working files of the panel from the bare board house that made the array. We then send that along with our specs and single gerber (original files) to any other board house we use to make the bare boards.This way array, rails, fids and elctrically they are wasy to match from house to house