Affordable 2 layer PCB assembly service / Need advise - Page 1
Forum section: electronics / general

author: satrs
author_rank: Newbie
timestamp: September 14, 2019, 08:54:35 pm
content: Hi, everyone!If there is a active topic like this, i will remove and rewrite it there.I just received order on 2000 devices, but now I have big headache about, how to choose PCB manufacture and assembly service provider. Which one is more reliable?Currently I am looking for PCB assembly services in China. Recently I have ordered PCBs from Pcbway and Jlcpcb couple of times, but don't have any experience with PCB assembly service.I need advice. What's your recommendation, for choosing proper manufacturer for PCB assembly service? There are many other manufacturers like this, which one would you recommend?Plz don't suggest any other options then China. I am not in USA and there is no PCB manufacturer near me.Some datails: 2 layer board 100x100mm size. with 2 layer assembly, no BGA, 20 Through-hole parts and 60 SMD.

author: Yansi
author_rank: Super Contributor
timestamp: September 14, 2019, 09:02:20 pm
content: Have you at least tried to search on this forum?Even in this same category "Manufacturing & Assembly" you can find these three topics even in the first like what 10 topics:https://www.eevblog.com/forum/manufacture/jlcpcb-smt-assembly-service-208764/https://www.eevblog.com/forum/manufacture/jlc-pcb-prototype-assembly-incredibly-cheap/https://www.eevblog.com/forum/manufacture/inexpensive-non-chinese-source-for-pcb-manufacturing/

author: satrs
author_rank: Newbie
timestamp: September 14, 2019, 09:11:06 pm
content: Yes, I found this jlcpcb related topics, but i need full assembly, not only SMT.Anyway jlcpcb is the last option for me.

author: Simon
author_rank: Unknown
timestamp: September 15, 2019, 07:13:58 am
content: I would not go sntraight to china with a 2000 peice order. You have no idea what garbage you will get back. I once got PCB cart to quote me and they were as expensive as my local assembler. I would get someone local to do them. You have not put your country so it is hard to tell you where to go outside of china.

author: SteveyG
author_rank: Unknown
timestamp: September 15, 2019, 07:18:37 am
content: For 2000pcs, many of the prototype assembly houses will not be of use as the quantity is too high. You will need to find a proper assembly house for production devices.Where are you based?

author: Yansi
author_rank: Super Contributor
timestamp: September 15, 2019, 08:06:21 am
content: I think he is from Georgia - at least, the flag was there.PS: PCBcart is extremely expensive, no wonder

author: Simon
author_rank: Unknown
timestamp: September 15, 2019, 08:08:12 am
content: no idea, I use them for PCB's and am happy. Iassumed any chinese assembler would be cheaper thn local but i was wrong and also realize that i get what i pay for.

author: Yansi
author_rank: Super Contributor
timestamp: September 15, 2019, 08:10:09 am
content: As a sidenote - I have never used china assembly services, apart from quoting a few (oh well...) We have always used local ones and always accepted the extreme pricing as a must.

author: Simon
author_rank: Unknown
timestamp: September 15, 2019, 08:19:26 am
content: My local assembler usually quotes the price of the PCB's if made in the UK and the parts from the distributors so they are not really expensive at all. I could not do it cheaper if i was stupid enough to hand build them myself.

author: Psi
author_rank: Super Contributor
timestamp: September 15, 2019, 08:33:08 am
content: Advice for your BOM line items if you're getting the PCBA company to order parts for you.Don't say on a critical item.. "This part MUST be genuine" because they don't know how to check or do that.Instead, say something like.. "Supplier MUST be Digikey or Mouser ONLY"I have found that to work much better.

author: voltsandjolts
author_rank: Unknown
timestamp: September 15, 2019, 08:41:33 am
content: Is it just me who thinks 'satrs' is a spammer?edit: OK, probably not. Just thought new user discussing assembly, mentioning JLCPCB was fishy just as JLC Assembly kicks off. But I was wrong.

author: SteveyG
author_rank: Unknown
timestamp: September 15, 2019, 09:14:08 am
content: Quote from: voltsandjolts on September 15, 2019, 08:41:33 amNot seeing it. What are they spamming?

author: satrs
author_rank: Newbie
timestamp: September 15, 2019, 10:03:31 am
content: Thanks everyone for response.QuoteI am going to make 10-20 peace order and then make assumptions. For final assembly i will visit the factory and be involved on functional test, to eliminate all feasible errors.QuoteSorry for that, I will show my location.QuoteI have 10-15 assembly house options on my list, so I am confused little.I am from Tbilisi, Georgia. There is no local PCB manufacturer near.QuotePast I allways use to order from Digikey and Mouser, but this days, it's very pain in the ass, compared to lcsc.com and alibaba.It's definitely true for some parts, example I ordered 50 pcs MPU6050 from aliexpress, 20 of them was defective one. I should note them first.QuoteI asked first and there is a moderator to make decision.

author: Psi
author_rank: Super Contributor
timestamp: September 15, 2019, 02:15:36 pm
content: Quote from: satrs on September 15, 2019, 10:03:31 amYeah, you do need to make a call on what parts to go 'known genuine' on and what parts to get from places like LCSC.- Always go known genuine on any tantaium caps (I'm looking at you Apple)Maybe ceramic too if they're small but high value, i.e. pushing the limit of what's possible in small packages.- Always go known genuine on any parts that have non-standard features that you rely on. etc. special voltage reg with reverse polarity protection. These sort of parts have a premium cost so are a tempting target for fakes. It's easy and profitable to grab a 7805 and stamp the other part number on it.If fake parts are used you may not notice as the product may seem to work fine. So always test these sort of features as part of your testing.(If you find multiple potential parts you could select for your product pick the one with the weird shape/pincount/footprint to help reduce the chance of fakes. It's harder for them to re-label chips with weird footprints because they don't have a large stock of similar but cheaper parts.)- Always go known genuine on any parts you are using at close to their rated spec. etc. ADC noise level, Opamp distortion, FET running hot. It's easy to end up getting factory rejects where they are actually from the genuine factory but were supposed to have been destroyed because they were binned and found out of spec.For a lot of parts you don't really care too much if the spec is off by 1% but, when you do care, make sure the part is genuine.

author: 48X24X48X
author_rank: Frequent Contributor
timestamp: September 17, 2019, 03:49:14 am
content: I was in your situation about a year ago. We ended with a factory in Shenzhen in the end.We did a survey of companies and send a request for a quote. From the quotes itself you already can filter out some of the companies. Good ones will give very detailed information in the quote. We then pay a visit to the trimmed list of companies in Shenzhen. Here is where you can really know whether the company is just a trading company or actually owning the factory. Our visit spans across really shabby factories that are not even own by the company we contacted with and to factories that are properly run. Workers that properly dressed with the coat, shoe, cap and anti static straps and organized lines are few of the criteria that we were looking for. Proper components storage and receiving area are also one of the aspect we looked at. Dedicated area for testing is also one of the most important aspect we were emphasizing on. As we needed box build and packaging, it is one of the service we need the factory to offer. And if you need certain service like X-Ray and test jig build, you need to make that as a requirement early on. From this visit, we decided which factory we wanted to use.We then did a pre-production run of 30 pieces with one of us being there. They then sent us the 30 pieces to test. This is where you can catch any mistakes done by the factory. Ours was a simple mistake when a connector mounted reversely. Device was running perfectly. This visit also allows us to fine tune the entire test process and packaging procedures which must also be included in a detailed document manual with clear pictures and annotations.During the real production stage, we hired a part time local engineer that used to work for Foxconn that speak good English for handling some troubleshooting issue if it does pops up as none of us were present. A small 100 pieces was first assembled, verified and tested. Then, the remaining units was assembled. Our test jigs was also remotely accessible to see the progress and troubleshoot if needed. You also need to verify the box build and how your product goes in the retail packaging if you have them.Regarding the BOM, you totally have control of which part you want them to supply and where to get them. Important parts we would directly buy them from manufacturers and ship them into China. Importing into China has VAT tax but can be reimbursed if you are not a local company. Importing parts does require every single detail even for the batch and date code of the parts! Less trivial parts like your regular capacitor, resistors, connector are supplied by them. Some parts we bought directly from proper distributor channels in China itself which is preferable to reduce cost and the VAT tax procedure.We also have the packaging made in China and ship over to the PCBA company. The enclosure was also moulded in another factory in Shenzhen.All in all, it is a very manageable process if you want to get your hands dirty. Some people would just hire a turnkey company to do everything for them but we are glad we didn't. Yes you might have some sleepless night but it's a valuable learning curve and after a while, you get the hang of it.

author: OwO
author_rank: Super Contributor
timestamp: September 17, 2019, 04:39:43 am
content: Quote from: Psi on September 15, 2019, 02:15:36 pmI would say LCSC is for "known genuine" and taobao/shenzhen market is for non critical parts.Be very careful which parts to consider as "non critical".Contrary to popular belief it's not the passives that you should be skimping on, and passives usually are a small fraction of the BOM cost anyway. Connectors are also something most think as non critical but I would ONLY buy from reputable sources, because connectors usually fail first in a product. Usually my formula is to get the majority of the lower cost parts of the BOM from a proper distributor, and play shenzhen market gamble with the few high value parts (e.g. FPGAs, RFICs, and anything expensive). That way it's easy logistics wise to do sample testing and any failures are easy to troubleshoot (90% of the board is "known good"). It is unintuitive, and I find most people doing the opposite (skimping on passives while buying FPGAs from digikey at 1000% markup), but in all my years of selling products made with shenzhen market parts I have not had a single defect that can be blamed on an IC.

author: Psi
author_rank: Super Contributor
timestamp: September 17, 2019, 07:24:46 am
content: Quote from: OwO on September 17, 2019, 04:39:43 amNope LCSC has fakes/bad-parts.I got some SMT fuses from their just a few months back and they never blow. They get so hot the solder holding them on starts to melt and they smoke.

author: SteveyG
author_rank: Unknown
timestamp: September 17, 2019, 09:09:46 am
content: Quote from: Psi on September 17, 2019, 07:24:46 amWhat did they say about it? They have a genuine parts guarantee.

author: Psi
author_rank: Super Contributor
timestamp: September 18, 2019, 06:57:54 am
content: Quote from: SteveyG on September 17, 2019, 09:09:46 amI didn't follow up, it was part of a PCBA order, i didn't get them directly.PCBway ordered the parts from LCSC, or they say they did.I have no way to really prove it.but i think it's more likely they were bad parts from LCSC than it is likely that pcbway lied to me that they got them from LCSC.This is the fuse in question, in case anyone want to order some and confirm/have a play.Might make a cool video.https://lcsc.com/product-detail/Surface-Mount-Fuses_SMD1812P300TF-16V_C55996.htmlSupposed to trip at 5A but if you overcurrent them at 12A on PSU they get so hot the solder melts and they smoke.The material they used doesn't seem to have any PTC properties at all.

author: satrs
author_rank: Newbie
timestamp: September 24, 2019, 09:21:09 am
content: 48X24X48XGreat experience, can you share us your findings, actual names? It will be helpful for others.There is a forum thread for exactly this.https://www.eevblog.com/forum/manufacture/some-china-pcb-manufacturer-recommend/100/Or send me pm.Unfortunately we don't have enough budget and time resources to make such findings, to visit multiple factories and hire someone for production monitoring.

author: marshallh
author_rank: Unknown
timestamp: September 25, 2019, 08:43:32 pm
content: I've got fakes from PCBway on multiple runs. LD1117 2.5v which was confirmed to be a fake via die decapping. If you want to avoid this you can specify some vendor-specific variants of a similar part that isn't commonly copied.Pcbway has been on the whole ok for me but not without problems. Never had issues with 4layer stuff but have had issues with the 2layer pcb line. 100 boards with VCC/gnd dead shorted due to a masking/aperture issue (not my problem btw).If you are doing more than a thousand or two thousand I would highly suggest paying a 3rd party or going there yourself to handle issues and maintain accountability. Try a smaller batch first and then re-order the rest later. If you do repeat business, however, that can work against you as the quality will eventually suffer if the company can take advantage of your "loyalty"

author: Psi
author_rank: Super Contributor
timestamp: September 26, 2019, 12:32:28 am
content: Quote from: marshallh on September 25, 2019, 08:43:32 pmOut of interest, what info did you put on the BOM for that item? Did you tell them it had to be purchased from digikey/mouser etc..

author: marshallh
author_rank: Unknown
timestamp: September 26, 2019, 01:44:15 am
content: Quote from: Psi on September 26, 2019, 12:32:28 amMy entire BOM was all digikey part numbers with Supplier: Digikey. Another fab I was buying from always bought the digikey parts, because the date codes they'd end up with were always the ones I'd get when i ordered myself. But Pcbway uses their own suppliers. I think this is fairly common.

author: Psi
author_rank: Super Contributor
timestamp: September 26, 2019, 03:59:23 am
content: yes, but giving a digikey part number doesn't tell them that the part must be purchased from digikey.If you want them to do that you have to say on the line item "ATTENTION ! PART MUST BE PURCHASED FROM DIGIKEY"

author: 48X24X48X
author_rank: Frequent Contributor
timestamp: September 26, 2019, 04:17:13 am
content: If purchase from outside of China (even Taiwan), you will be charged VAT tax which will be partially reimbursed (a small portion not refundable due to some handling charges). If no VAT mentioned, it's very obvious parts not purchased from your preferred seller. We did our own purchase for anything outside of China.On PCBWay, we did went for a short tour. My personal opinion, if you are doing one off or prototype, it's okay. Anything other than that, get a proper factory. Everything is messy and disorganized.