JLCPCB good for more than 2L PCB - can they follow instructions ? - Page 1
Forum section: electronics / general

author: mon2
author_rank: Frequent Contributor
timestamp: December 28, 2021, 12:23:39 pm
content: Hi. Quite frustrated with a recent job submission with JLCPCB for a rather simple 4L PCB. Anyone have senior engineering contacts at their factory that may know what they are doing on PCB processing ?They have removed the solder mask off our submitted fileset and simply do not understand the fault. The order is still being processed but not sure if we will go back for this torture in the future. As we are paying by the minute to review their errors and had to chat in the middle of the night 4+ times, causing loss of my beauty rest.Their comment is that we should not have approved the file - well heaven forbid, yes our staff took the weekend off. Did not think to have to babysit and check for their factory generated errors.I suppose we can fix what they have broken.It may be wiser to stick with our mainstream Suntak / China Fast Print / Yaxinda PCB shops. They simply get it done right, the first time.

author: JPortici
author_rank: Super Contributor
timestamp: December 28, 2021, 12:28:50 pm
content: I've never used JLC for production, but none of the 4L boards i've sent have had issues in fabrication. Sure it's frustrating when you're stuck talking to a middleman who can't understand you or relay your message properly

author: rpiloverbd
author_rank: Regular Contributor
timestamp: December 28, 2021, 12:30:51 pm
content: Sorry, I have no contacts at JLCPCB factory. Many senior engineers hang around here. I hope somebody will surely of good help to you. I think, for multilayer PCBs, Rayming PCB is a good alternative. They do rigid PCBs up to 20 layers. And flex PCBS up to 8 layers. Their communication with the customer is also satisfactory as far as I know.https://www.raypcb.com/rigid-flex-pcb/

author: mon2
author_rank: Frequent Contributor
timestamp: December 28, 2021, 12:41:55 pm
content: Thanks guys. I recall Rayming from past chats (perhaps even met them at HK trade fairs) but have not used them yet. JLCPCB factory also pinged back and now their machine is in motion, errors and all that were generated by their side.Originally thought no big deal - we can manually fix any solder bridges and perhaps their equipment cannot handle fine pitch parts with solder mask. However, our USB Type C connector has the spec'd in solder mask yet a larger, more coarse pitch 28 pin device is now missing the solder mask. Of most concern are the tiny TDFN (diamond shaped) LDO regulators we like to use as they are of the few available under the semiconductor crunch.Just sucks to have to repeat the same statements over and over in the middle of the night. Factory is saying to accept the boards as-is and report back any faults and they will make it right.Made it clear that if there is a next time, do not want amateur hour reviews of the submitted jobs. If we have to continue to pay on the backend to correct their faults, where is our savings in this business deal ?I guess we are getting what we paid for.

author: thm_w
author_rank: Super Contributor
timestamp: December 29, 2021, 11:15:20 pm
content: So they only removed the mask in some areas. What was your DRC rule set to in terms of minimum sliver?https://www.eevblog.com/forum/manufacture/minimum-gap-for-solder-mask-between-pads-at-jlcpcb/

author: Cerebus
author_rank: Super Contributor
timestamp: December 30, 2021, 02:26:45 am
content: JLC's capability specs are rather opaque, to put it mildly. Their minimum pad to solder mask figure is 50 microns and their minimum solder mask 'sliver' width is 100 microns. I haven't had cause to test the latter yet, but from the 4 layer boards I have had from them they have significantly exceeded the precision that 50 micron figure implies. I have no doubt that on the 4 layer boards with 1oz top copper that they'd manage a 100um minimum solder mask width with no trouble BUT if your solder mask wanders under that by even a micron I suspect that their own DRC will ruthlessly strip it off.So far I haven't had a board from them that wasn't exactly "to drawing", but I've been very careful to go through their capability specs with a fine tooth comb, followed them religiously and where they were unclear, erred on the conservative side.

author: lordium
author_rank: Regular Contributor
timestamp: December 30, 2021, 02:58:55 am
content: We use them for most PCB here at our company (Automotive, and only PCB not assembly), and I don't we ever had any issue. 2,4,6 Layer and BGA etc. and all kinds of strange and oversized PCB (even outside their stated dimensions on their webpage). Also personally use them too, still never had a problem there.I think maybe you have a communications problem or not labeled the files according to their specification. Or maybe the experience is different from outside china, as I can only give my perspective from inside.

author: DIYGUY Chris
author_rank: Contributor
timestamp: December 30, 2021, 08:41:03 am
content: Whenever wrong things occur, I always check how to fix it first then I check what caused these wrong things to prevent it from happening again and it is great that you thought it the same way.First verse, I know many persons at JLC so you can forward me the details of the accidental event and I can play your new "man in the middle" if this is gonna help. Also maybe you want to talk to Rebecca through rebecca@jlcpcb.com I'm pretty sure that she will not let the case down.As I know, each JLC customer has a "account manager" which is a specialist person that you can directly Email whenever you need help (I recommend Sophie) also the support team are available through their official Email support@jlcpcb.com so I wonder if you have had contacted them, you can also start a "quality complaint" directly from the order history.Considering all these options I don't think that JLC are willing to ignore any case.

author: nvmR
author_rank: Regular Contributor
timestamp: December 30, 2021, 10:12:17 am
content: I have also used JLC for 2,4 layer jobs. I have found that as long as you consider the time differences, and try to make orders with enough time to respond during your workday, and making orders not near the weekend, they are well worth the money saved and the simple interface.Their chat support is fairly good, and the assembly service is also mostly good.

author: thinkfat
author_rank: Unknown
timestamp: December 30, 2021, 10:29:52 am
content: I've used JLCPCB for 4 layer PCBs down to 0.4mm pad pitch (QFN packages). Their minimum solder mask sliver is rather generous, but so far I didn't have problems with it. The problem is mostly that they don't exactly specify what they can do regarding solder mask so it's difficult to anticipate what they will do to your Gerbers.

author: mon2
author_rank: Frequent Contributor
timestamp: December 31, 2021, 12:59:07 pm
content: Thanks everyone for your feedback and comments.Celia is our rep but Rebecca has also reached out to us to investigate to satisfaction. As of yesterday, Celia acknowledged the solder mask was removed from our PCB for areas where we had it in place. This is for 3 parts on the design. One being a 28 pin SSOP. Not worried about this device as it is rather simple to fix for any solder bridges. More concerned about the X2SON LDO devices (1.0*1.0mm package) and a small SMD diode with a small pitch. Our USB Type C connector has the solder mask in place between the solder pads.The 28 pin SSOP solder mask should not have been removed without an alert from the factory. Yet they claim they did not modify the original fileset. Perhaps their import tool is the root cause ? Regardless, they removed the solder mask.They are willing to correct the issue after their investigation but wanting us to continue to build and ship to us. As if we have a choice at this stage. Believe the boards are finished as of this writing so we should receive them in the next week or so via DHL.Johnny don't need no soldermask

author: thinkfat
author_rank: Unknown
timestamp: December 31, 2021, 03:23:29 pm
content: Do you have any places where a pad is defined by solder mask instead of copper? If not, you'll probably be fine. Solder mask doesn't do a lot against bridging, it's mostly a safeguard against solder alloy being wicked off of pads by connecting traces or vias and causing dry joints because the fillet doesn't form properly. Sometimes, adjustments to the stencil can then help.

author: thm_w
author_rank: Super Contributor
timestamp: December 31, 2021, 09:39:30 pm
content: Quote from: mon2 on December 31, 2021, 12:59:07 pmYou haven't answered the question though, what was your DRC for minimum sliver + expansion? What was the actual width of the mask?

author: nigelwright7557
author_rank: Frequent Contributor
timestamp: January 01, 2022, 02:47:45 pm
content: I have used JLCPCB for a few years now and not had many problems.I got a message from them saying a pcb came out bad, 1 from a batch.I ddint dream for one second they would actually send it to me in with good pcb's.First I knew a customer was complaining of 6 mm hole through the pcb that shouldnt be there.A few times I have had rejections of files for various reasons.Oddly just sending same files again they went through ok.For me JLCPCB win on price every time and quality normally is excellent.

author: Siwastaja
author_rank: Super Contributor
timestamp: January 02, 2022, 04:39:45 pm
content: Maybe you have wrong expectations?High definition solder mask for tiny sliver width is an expensive special process. If you really need that, you should be looking into high-end manufacturers, with 10-100 times the cost. Then you also get the classic process of back-and-forth communication with the actual engineers.IMHO, it's normal to remove soldermask between pins of 0.5mm pitch devices; either by yourself in CAD, or by the manufacturer. This is visible in most commercial products.

author: mon2
author_rank: Frequent Contributor
timestamp: January 02, 2022, 09:23:10 pm
content: QuoteTBH - thought the same. However, the paradox is that the USB Type C connector has a finer pin pitch and yet the solder mask is still present in that region of the PCB. Yes, we deal with many other PCB shops and they are not that much more expensive but still are higher in cost than JLCPCB (ie. Yaxinda, Suntak, Founder PCB, China Fast Print, Kingford PCB, etc.).I will know more about the DRC tomorrow for this PCB design.

author: thinkfat
author_rank: Unknown
timestamp: January 03, 2022, 09:03:47 am
content: Well, lesson served: Always set up your manufacturing constraints to what the manufacturer can actually do so to not have surprises when you receive the boards.Another hint: You can download the whole set of manufacturing files from your JLCPCB account. IIRC, they even have before/after Gerber files so that you can for yourself what adjustments have been made.

author: mon2
author_rank: Frequent Contributor
timestamp: January 03, 2022, 09:53:21 am
content: JLCPCB admitted that they made the error. The lesson to be learned is on their side.

author: thinkfat
author_rank: Unknown
timestamp: January 03, 2022, 11:10:17 am
content: Quote from: mon2 on January 03, 2022, 09:53:21 amAnd not on yours, too? Hmm...

author: thm_w
author_rank: Super Contributor
timestamp: January 04, 2022, 11:07:01 pm
content: Quote from: mon2 on January 02, 2022, 09:23:10 pmPitch is not a definitive answer, although you are generally correct. Which is why I've repeatedly asked for sliver.I can have a 2.5mm pitch part with 2.4mm wide pads, now the gap between the pads is small, 0.1mm. This can occur if you've made a custom footprint, or per part solder mask expansion values, etc.

author: Uky
author_rank: Regular Contributor
timestamp: January 11, 2022, 09:47:11 am
content: Ordered two small batches of boards from JLPCB.One batch came out perfect. The other had silkscreen for mask instead of mask...The fault was on my side: Wrong name on that particular layer. No question about it.My bad.BUT: Anyone at JLPCB should have noticed this if he/she had a look at the gerber filesand if I had been that person, I would have e-mailed and asked: We see that white silk screencovers solder pads all over the board. Is this really correct!?, in which case I would have asked to havethat part of the order cancelled immedeately. When the boards arrived and I saw what had happened,I e-mailed JLPCB customer service and asked if theu could rename that layer and re-processthe order.No answer.I corrected the error and submitted a new order. The new boards arrived yesterday.Perfect and no problems.So - I take it that there is actually no-one at the wheel at JLPCB for small ordersand that these are processed fully automatic without any human intervention.Therefore: Everything has to be 100% correct when submitting an order.I am about to order other boards, but Covid makes me hesitate to usea non-european manufacturer as I have been noticed that air transportationout from China will be limited because of lack of flight staff and generalquaranteen rules.

author: JPortici
author_rank: Super Contributor
timestamp: January 11, 2022, 01:55:28 pm
content: Quote from: Uky on January 11, 2022, 09:47:11 amTip #1: in their order form you can check an option so you have confirm their production files, otherwise they won't ask (though they asked in the past anyway when i did uncommon things like silkscreen over pad)Tip #2: Nah, we've recently received our boards within the standard timeframe, but chinese new year is about to happen so you might want to order sooner than later

author: T3sl4co1l
author_rank: Super Contributor
timestamp: January 11, 2022, 02:32:01 pm
content: I guess newbies in this space, see the prominence of JLC, and expect they must be good -- good enough to apparently be popular -- and look at the price and figure, how can I lose, it's so cheap?The history as I understand it, is JLC is one of the newer entries to the market, and through "shady" dealings (spamming forums, sponsored promotions), and I presume, considerable automation on their backend (both for processing files, and in the actual printers), have cut prices lower than ever.(Or was that PCBWAY that was spamming? I forget already.)So some may be unaware that such services really are cut rate, for all that implies.You get boards. They can be soldered. They probably don't have shorts/breaks differing from the fab files.You get their stackup. (Custom stackup? Ain't no one got time to read that.)You get their materials (whatever soldermask, silk, etc. ink are used).You get their quality process (whatever range of blemishes, plugged/tented vias, soldermask webbing, plating thickness, layer alignment, etc. they consider acceptable).If you want something slightly off the beaten path, think for a moment: should I be shopping for $thing at Walmart, or a store specializing in it?Do you buy your tools at Walmart? Harbor Freight?Mind, not setting up a guilt trip here: there is a time and place for everything. I have some HF tools. I don't expect much of them, and they get it done most the time. Simple cheap protos -- maybe you're going to rip into them anyway (because you goofed up on component choice, wiring, etc. -- yes, I've done this plenty of times, too!), and honestly, the weaker grade of soldermask makes it easier to expose traces, making new pads and such.But if you expect something a bit tighter, or well supported (customer service), or a custom stackup, or production quality -- you're expecting too much from them. They simply aren't in that kind of business. Go elsewhere; you will pay more, and you won't regret it. You may even pay less, in quantity (100s, 1000s of units).Likewise for their assembly service: don't expect rigorous AOI, let alone flying probe test or rework; placement and soldering defects have been reported here before. Expect some amount of fallout, or do the rework yourself.For reference, typical full-service board fabs are in the $100 range, and assemblies in the $1000 range. Eye-watering for a hobbyist, true; but very much, cheap to on-par, for the professional.Tim

author: Cerebus
author_rank: Super Contributor
timestamp: January 11, 2022, 04:15:05 pm
content: Quote from: T3sl4co1l on January 11, 2022, 02:32:01 pmI don't recall any confirmed incidents of JLC spamming, on the other hand Idorecall that PCBWAY were caught out misbehaving any number of times.QuoteI wouldn't disagree with any of that. What the stunning inexpensiveness of JLC (and their ilk) does permit is doing things that you might not otherwise. An upside down version of "opportunity cost" if you will.Some months back I was having problems with a breadboarded prototype, might have been signal integrity, might have been stupidity on my behalf, might just have been noise/stray coupling in a breadboarded environment. I strongly suspected that it was something that would go away once everything was on a proper PCB with proper power and ground planes. This also involved some OCXOs of dubious provenance so I also wanted to be able to soak test those in a 'clean' setup. I ran up a quick4 layerboard design isolating just the troublesome sub-circuit, complete with nice clean coaxial test points, and fired it off to JLC and got it back a couple of weeks later. A little bit of solder later and my suspicions were confirmed, it was just my crappy breadboarding. I spent under £50in total, confirmed my suspicions that all would be well once I got the sensitive analogue electronics on a proper board, and got a set of boards that I could run a soak test several OCXOs on.I would not have gone down that road if I'd been paying 'proper' board house prices, the experiment would have been too expensive for something that was essentially a 'throwaway' once it had done its job.

author: nigelwright7557
author_rank: Frequent Contributor
timestamp: January 12, 2022, 02:47:02 am
content: Quote from: lordium on December 30, 2021, 02:58:55 amI have had about 200-300 pcb's made by JLCPCB and only had one bad pcb.They let me know one pcb was bad and I thought thye would just bin it but they put it in with good pcb's and of course it got sent out a customer !Luckily customer was understanding about it but I had to pay to send another pcb.They sometimes reject my files despite them being correct and simply resending them see's them go through ok.I can only guess someone different checked the files second time through ?I have used JLCPCB prefferred filename extensions where possible.However they dont like board outline that I put on my silk screen layer.