pcbway - a precautionary tale

Go To Last Post
24 posts / 0 new
Author
Message
#1
  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

Here's another story regarding PCB manufacturer PCBWay. However, I thought I might be different and tell you of a nasty problem I've run into with them.

 

I ordered a small batch of PCBs to be manufactured and assembled by them. The assembly isn't all that difficult to do by hand, but I wanted to try out their assembly service to see how well it works, as I have some upcoming assembly orders that I need an assembly house for. After my boards arrive, I hook up the power input to 12V, and measure the 3.3V Vcc rail. Vcc was well above 3.3V, so I checked the LDO used to generate 3.3V. It should be a microchip mcp1703a. Here's the IC that pcbway supplied and assembled for me:

 

U2

 

The mcp1703a should be marked with JKXX, not CS9H. At a very rough guess, I think they erroneously supplied an mcp1700t for U2. The mcp1700t has a maximum input voltage of 6V, well below that of my DC input. I've checked the BOM that I sent to PCBWay, and yes, it does specify an mcp1703a.

 

I've let PCBWay know, and will update this thread if there's any news, but in the meantime, I have a bunch of useless boards.

 

- S

 

ps: yes, U3 is an attiny9.

 

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

Oops

 

Thanks for sharing Stephen.

Ross McKenzie ValuSoft Melbourne Australia

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

As I use PCBway for all my PCB and assembly I am surprised that they made this mistake.  They always confirm BOM's with me and get a sign off.  I am about to pull the trigger on a very nice size build of two different boards, and rather intricate as well.

 

You mention that the boards are not difficult to assemble, how many did you have made, and how many are destroyed?  Can't you remove the part and replace it?  I know that this should not have happened but surely a three pin SMD device should not take much to do.

 

valusoft wrote:

Oops

 

Thanks for sharing Stephen.

Indeed, please do keep us up to date.

 

JIm

If you want a career with a known path - become an undertaker. Dead people don't sue! - Kartman

Why is there a "Highway to Hell" and only a "Stairway to Heaven"? A prediction of the expected traffic load?  - Lee "theusch"

Please Read: Code-of-Conduct

Atmel Studio6.2/AS7, DipTrace, Quartus, MPLAB user

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

jgmdesign wrote:

As I use PCBway for all my PCB and assembly I am surprised that they made this mistake.  They always confirm BOM's with me and get a sign off.  I am about to pull the trigger on a very nice size build of two different boards, and rather intricate as well.

 

They also sent me the BOM quote for approval. That quote indicated the correct mcp1703a part.

 

jgmdesign wrote:

You mention that the boards are not difficult to assemble, how many did you have made, and how many are destroyed?  Can't you remove the part and replace it?  I know that this should not have happened but surely a three pin SMD device should not take much to do.

 

Replacing the part is definitely doable - I ordered 5 boards, and all 5 boards need the mcp1703a replaced. Additionally, on the single board that I powered up, the attiny9 (the only IC powered from the 3.3V output of the mcp1703a) might need replacing also. You can see from the pic that there's plenty of room to rework these two chips.

 

So, reworking these boards is doable, but if I'm going to that trouble, I might as well do the entire assembly myself :-(

 

- S

 

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

Stephen,

 

I presume that pcbway supplied all  the parts and then loaded them. Ask them to explain how/why they bought the wrong part.

 

Leaving aside the wrong part loaded, how would you rate the overall assembly, timing, packaging and delivery (especially the cleaning).

 

Ross McKenzie ValuSoft Melbourne Australia

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 2

Clearly their mistake.

 

I would ask for either a full refund of you money, or to have them re-do the boards at their cost.

 

They clearly failed to provide the service you paid for.

 

JC

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

valusoft wrote:
I presume that pcbway supplied all  the parts and then loaded them. Ask them to explain how/why they bought the wrong part.

Yes, I requested their turnkey service, in which I send them a BOM, and they would purchase the parts themselves. In my case, the BOM included the full MPN (MCP1703AT-3302E/CB) and a digikey part number for cross-checking (MCP1703AT-3302E/CBCT-ND).

 

DocJC wrote:
I would ask for either a full refund of you money, or to have them re-do the boards at their cost.

 

They clearly failed to provide the service you paid for.

Yes, that's what I would expect from a pcb house that I'd send my business to.

 

valusoft wrote:

Leaving aside the wrong part loaded, how would you rate the overall assembly, timing, packaging and delivery (especially the cleaning).

I'll review the boards and assembly service later (when this issue is resolved).

 

In the meantime, I got a reply from them. They've claimed that their supplier sent them the wrong part. I was given no further explanation of how that happened, or who the supplier was. They've also offered to send replacement parts, presumably for me to do the rework myself. So far, their response has been quite underwhelming.

 

- S

 

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

Companies like GoldPhoenix will actually buy the parts you specify from Digikey and Mouser. You can elect to have them source components from ‘local’ suppliers but that is fraught with trouble. My recent transaction had thrm miss the last item in the BOM which was a unidirection transzorb. The ones they ‘sourced’ had no cathode marking and they wanted to know which way to install it. I reiterated the part number abd gave a link to the datasheet, so they ended up getting some from a different supplier. There were some question i had regarding various charges they added that never were explained to me and they ended up dropping. I am still none the wiser. For me, it wasn’t so much the question of the money, but rather what they were charging me for.
Apart from that, the boards were assembled as i expected - they did send me photos to verify before they shipped. You really need to check all the part codes etc as once it’s on the plane, there’s no going back.

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

 They've also offered to send replacement parts, presumably for me to do the rework myself.

Obviously they are looking for the cheap resolution to the problem.

 

I would continue to say no, and request either your full refund, or new boards.

 

Clearly, also, the board that was over-voltaged is now unreliable and worthless for any serious work.

 

JC 

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

Doc - good luck with that strategy. They've got the cash- anything else is total loss to them and their margins are small. The service is cheap 'n' cheerful and for the most part it works. The best you could expect is a discount next time.

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

Kartman wrote:
... and their margins are small.
Could evaluate a PCBA fab that has larger margins.

There's one mention of MacroFab (Houston, Texas) :

https://www.avrfreaks.net/forum/using-aref-another-digital-input#comment-2287861

 

https://macrofab.com/company/

 

"Dare to be naïve." - Buckminster Fuller

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

Kartman wrote:

Doc - good luck with that strategy. They've got the cash- anything else is total loss to them and their margins are small. The service is cheap 'n' cheerful and for the most part it works. The best you could expect is a discount next time.

 

+!

 

I have had an issue or two with them but in one case it was clearly my fault, the other I think I simply replaced the part as it was not worth the trouble as they provide me with better service than the American places here I have tried.  And found out that they send the work I am paying top dollar for to China to be done anyway.  So you kinda have to pick your battles carefully.

 

Kartman wrote:
Companies like GoldPhoenix will actually buy the parts you specify from Digikey and Mouser.

So does PCBWay.  If yu put a Digikey or Mouser part number on the BOM, AND tell them to purchase it from them they will do it.  It you put on the BOM "Or Equivalent" then you are at their mercy.  What I do is make it clear on my order that I want all overages sent back to me with the order when shipped.  Not only do they send that back, they also send back the empty bags from Mouser and Digikey as proof of the purchase as I can track who bought the parts from the markings on the bags.

 

Keep in mind I am not defending PCBway 100%.  I am just letting you know how you must handle things with them, or any Chinese PCB vendor as they all say the same thing...we built it based on....blah blah blah.  I got the same response from teh ones here in the USA.

 

JIm

If you want a career with a known path - become an undertaker. Dead people don't sue! - Kartman

Why is there a "Highway to Hell" and only a "Stairway to Heaven"? A prediction of the expected traffic load?  - Lee "theusch"

Please Read: Code-of-Conduct

Atmel Studio6.2/AS7, DipTrace, Quartus, MPLAB user

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

Another update. PCBWay has refunded the full price of the assembly and components. Kudos to them for taken responsibility in this way.

 

- S

 

ps: As requested by Ross, I'll post a review of the boards in this thread later today when I have a bit more spare time.

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

Congrats!

 

100% satisfied?

 

Jim

If you want a career with a known path - become an undertaker. Dead people don't sue! - Kartman

Why is there a "Highway to Hell" and only a "Stairway to Heaven"? A prediction of the expected traffic load?  - Lee "theusch"

Please Read: Code-of-Conduct

Atmel Studio6.2/AS7, DipTrace, Quartus, MPLAB user

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

jgmdesign wrote:
100% satisfied?

 

Of course :-)

 

Here's a quick review of their service. I had several different board orders done in a single batch. Some of the boards were PCB only, some were PCB plus assembly.

 

The quality of the bare boards was very good for all the orders. Alignment of layers was precise. I think my gerbers had a soldermask swell size of 0.1mm. I don't know if pcbway did any adjustment there, but even on the fine pitch (0.5mm) SMD pads, I couldn't find any soldermask overlapping the pad. And on those 0.5mm SMD pads, there was adequate soldermask between pads. For one of the orders (a 4 layer board), the bare boards came individually wrapped in bubble wrap. For another, the bare boards were put in a ziplock bag. For the others, the boards were stacked together in shrink wrap bubble wrap. There's some minor scratching on the surface of the boards, most noticeably on the boards placed in the ziplock bag, but I don't see any damaged soldermask or flaws that might affect solderability.

 

There was one board that had an obvious manufacturing problem - there was a gouge in the top copper underneath the soldermask. I'm guessing this happened during photoetching. Electrically, it's not an issue, as it's part of a ground pour, and there's no continuity break.

 

One of the orders was for HASL lead-free, but it looks like I got a free upgrade for that order to ENIG.

 

Overall, I'd say the bare boards are very good.

 

I also had assembly done on several of the board orders. These were turnkey assembly orders in which I supplied BOMs and PCBWay purchased the components on my behalf. These were all prototypes - the number of boards assembled per order was 5 or less. I'm guessing that the process used by PCBWay was to stencil print solder paste, hand place most of the components, bake in a reflow oven, then hand solder any remaining components. The components that went through the reflow oven were generally well soldered - you can see in the pic in the original post that all of the visible components had even amounts of solder filleting, and the components were well centred on their pads. I can see on one of the boards around 2 or 3 components that show signs of hand soldering - there are a blobs of uncleaned flux residue around those components. I'd guess that those components either were missed in the reflow pass, or somehow fell off before reflow. I can also see some uncleaned flux between the pins of some of the fine pitch SMD components. There are three or four areas where the solder paste smeared a little bit. I don't think these affect functionality of my boards, but I haven't thoroughly tested them yet.

 

Assembly-wise, I'm happy with them, particularly considering the hand placement. The most difficult board had components on both sides, and included 0402 passives.

 

There was an issue with packaging of some of these assembled boards. All of the assembled boards were placed in separate static shielding bags. However, the larger boards (100mm x 100mm) were wrapped in bubble wrap before placing them in the static bags, which kinda defeats the purpose of the anti static bags.

 

Time between payment and shipping was 20 calendar days. There was also a period of about a week before that during which the BOM was revised several times due to unavailable components. Shipping was 5 calendar days (DHL express).

 

Overall, the only major issue for me so far was the wrong component discussed in the original post, which they rectified by refunding the assembly and components cost for the affected board.

 

Communications was fine. Turnaround was either the same day, or in the morning on the next business day.

 

There are a couple of things which I need to do for future orders. Firstly, as suggested by others I'll give them a list of approved suppliers (digikey, mouser etc), and only allow components from other suppliers with my explicit approval. Secondly, I'll check board photos to see if the right components have been loaded (although that's not always possible - component markings aren't always legible). And finally, I'll include instructions not to put bubble wrap inside static bags of assembled boards.
 

Pics:

 

Flux residue would be a terrible name for an alt rock band:

flux res

 

TSSOP8 - 0.65mm pitch - footprint (please excuse my poor macro photography). Alignment of pads to soldermask and drilling can be seen here:

u6 footprint

 

eeprom mounted in that TSSOP 8 footprint. The white specs around the "U6" silkscreen are bits of solder paste residue:

u6

 

- S

 

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

Thanks for the extensive report Stephen.

 

Is that item a conductive piece?

 

Ross McKenzie ValuSoft Melbourne Australia

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

valusoft wrote:
Is that item a conductive piece?

 

Almost all of the white spots in that photo, including the one you've highlighted, are dust specks, and quite likely caused at my end. There's also a small scratch on the topmost pad of C12.

 

- S

 

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

That is good then Stephen. It just looked to be a golden colour like the actual pads.

Ross McKenzie ValuSoft Melbourne Australia

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

Flux residue would be a terrible name for an alt rock band:

I think you might be wrong, there ;-)

"Experience is what enables you to recognise a mistake the second time you make it."

"Good judgement comes from experience.  Experience comes from bad judgement."

"Wisdom is always wont to arrive late, and to be a little approximate on first possession."

"When you hear hoofbeats, think horses, not unicorns."

"Fast.  Cheap.  Good.  Pick two."

"Read a lot.  Write a lot."

"We see a lot of arses on handlebars around here." - [J Ekdahl]

 

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

DocJC wrote:

 They've also offered to send replacement parts, presumably for me to do the rework myself.

Obviously they are looking for the cheap resolution to the problem.

 

I would continue to say no, and request either your full refund, or new boards.

 

Clearly, also, the board that was over-voltaged is now unreliable and worthless for any serious work.

 

JC 

 

Or send the boards back to them and have them replace the parts.  That is what happens when we have a severe glitch, such as that.  The fact is, unless it is some sort of unrecoverable mistake, you can be sure that the best you'll get from any turn-key is reworked boards.  A wrong 3-pin SMD device does not fall under the term "unrecoverable!"  It can be replaced in under 30 seconds by an experienced rework solderer.

You can avoid reality, for a while.  But you can't avoid the consequences of reality! - C.W. Livingston

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 1

For what it would cost to send the boards BACK to China it is not worth it.  Its amazing that DHL from China to the USA is dirt cheap and FAST, but in the revers direction it is a pain in the A$$, expensive and SLOW.  

 

Just my experience with trying that  once....only once (laugh)

 

Jim

If you want a career with a known path - become an undertaker. Dead people don't sue! - Kartman

Why is there a "Highway to Hell" and only a "Stairway to Heaven"? A prediction of the expected traffic load?  - Lee "theusch"

Please Read: Code-of-Conduct

Atmel Studio6.2/AS7, DipTrace, Quartus, MPLAB user

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

"You shouldn't send me the wrong regulator, Johnny.
My faddah sent me the wrong regulator wunst... Wunst."

"Experience is what enables you to recognise a mistake the second time you make it."

"Good judgement comes from experience.  Experience comes from bad judgement."

"Wisdom is always wont to arrive late, and to be a little approximate on first possession."

"When you hear hoofbeats, think horses, not unicorns."

"Fast.  Cheap.  Good.  Pick two."

"Read a lot.  Write a lot."

"We see a lot of arses on handlebars around here." - [J Ekdahl]

 

Last Edited: Wed. Jan 3, 2018 - 12:41 PM
  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

There is somethins elso more than China we always let China the full marketi in this kind of thing.
We need to open doors in EU.
Try this one and let me know Smt Low Cost.
Regards ;)

Paula

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

One of my brothers bought a bunch of components from Mouser some time ago, among which were some resistors and they had the wrong value.

He complained and got a new batch of resistors for free.

They were the same wrong value as the first faulty batch.

 

No safe place untill you're pushing the daisies.

Paul van der Hoeven.
Bunch of old projects with AVR's:
http://www.hoevendesign.com

Last Edited: Tue. Feb 6, 2018 - 02:44 PM