ITeadStudio FPC mistake

[frank26080115]

I remember when Dave himself got a bad PCB back because the manufacturer decided to edit his file without asking him.

This is my first ever FPC design, I was very excited to receive it and put it together. But the power LED won't light up even when all the voltages are correct.

This is what happened:



I emailed ITeadStudio about it just now, probably won't get a response until Monday.

[Falcon69]

Wow!   Now I don't feel so cheap from buying my boards from an off the wall (aka, eBay) Chinese Manufacture.  Those boards look horrible to me.

Am I looking at this correctly?  Everywhere you had through hole, they placed a round pad for surface mount?

Also, the vias don't look very centered at all, and that silk screen, well, I won't even comment on that.

Thank you Frank, I feel much better about who I've been getting my boards from now.


EDIT:  Oops, I see it now.  Those were suppose to be square pads for surface mount, and they deleted a trace it looks like.  Why would they do that?  That's strange.  I thought all these manufacturers just do whatever is in the file you send them?

[c4757p]

That looks like shit! Glad their normal PCB service is better than that...

[c4757p]

I thought all these manufacturers just do whatever is in the file you send them?

I wish they would! I'd much rather they just sent me a "We can't make this, you suck at PCBs" and let me try again instead of screwing around with it. Even little things like putting a serial number on the silkscreen - how !%@(@# hard would "Here's your SN - make sure it's somewhere visible on the silkscreen" be?! I wanted that spot blank you bastards! I'm not paying you for PCB layout service! 

Of course, for all the babysitting, they sure as hell don't bother to do something as little as telling me about problems with my order. I sent in an order a while ago that I needed quickly, and they f-ed up one batch, so they had to redo it - and they never told me, so I get to sit here wondering where the hell my PCBs are. Then when I get them - they've included both batches and not marked the bad one! 

OK, ITEAD rant over.

[Falcon69]

c4757p

I know what you mean.  I tried a different company then my normal one, because they were cheaper.  I won;t use them again.  They placed (their) serial number on my board, true, it will be hidden by a component, but it wasn't what was in my file.  I will not use them again. I contacted them, and their response was that they do it on all "their boards" because they make too many to keep track of.  That's just it, it's not 'Their Boards', it's mine.

Anyway, that board the original poster di post, just looks like crap all around.

[c4757p]

I don't really have too much of a problem with the serial number, and I suspect that if I slapped "NO SERIAL NUMBER HERE" over an area in the outline layer, they'd probably do the right thing. But it would really be nice if the process consisted of simply this: Gerbers -> Automated Script to Convert to Their Machines' Format -> (Success? Make the damn boards. Failure? Email me.) Perhaps, since they do handle a lot of boards by beginners, a check box in the form: Do not check my Gerbers for me.

[Falcon69]

that's just it, in my email i sent them along with my gerber files, I specifically said that I don't want any other silk screening, except for what is in my file. They did it anyway.  Their boards were okay, except for that. 

Frank, is that board from Iteads special 5 dollar prototype thing they have?  Or is that from their actual premium type boards?  (or whatever they call their service, i've never actually ordered from them)

[c4757p]

Well, if their production process requires a serial number to track the board, they have to put it. They're not going to change their whole process. But I still suspect if I told them not to put a serial number here, but put it here instead, they'd oblige.

[frank26080115]

Frank, is that board from Iteads special 5 dollar prototype thing they have?  Or is that from their actual premium type boards?  (or whatever they call their service, i've never actually ordered from them)

It's their $70 FPC service, flexible film PCB, this is not FR-4, this is made with Kapton.

The soldermask layer has turned into circles, weird eh? There must be a good reason for this.

The highest resolution scan of this board I have is a 90 MB file. I'll try uploading it later

[Falcon69]

I see your point, but is I am paying for something, then it must be exactly as I say. They should at least contact the customer and say what their process is, and let the customer decide to go through with it or not. Instead of just opening the delivered package and finding it there.  Bad business in my opinion.

[c4757p]

I agree, they should warn you first. I guess I was expecting a nasty surprise anyway, since the specifications that they do publish are so poorly specified that I had already spent a good while trying to find things. Still don't know what their silkscreen resolution and registration are...

[Falcon69]

thats the flexible pcb boards? like whats in cell phones? I can't think of a reason why the soldermask layer would have the round instead of the square.  I could understand them in a flexible board changing from a square through hole to a circle.  A circle gives 360 degrees (infinity) of any one point where a rip can happen, making it stronger.  Whereas a square has 4 points that can easily rip.

It still doesn't make sense why they did that.  I don't see it causing a problem for the components. there's still a good surface to be soldered too.  But that missing trace, definately a problem.  For a $70 board, that is unacceptable to me. If it was a $5 board, I would almost expect a simple screw up like that.

[FrankBuss]

I never had a problem with their service. This is one of my boards they made:

http://www.frank-buss.de/tmp/cartridge-pcb.jpg

Yes, the vias are a bit off center and there was a serial number, too, but I don't mind, the board worked.

Interestingly, there was no serial number on another board I ordered some months ago (I tried the fancy white silk screen). Here is a 1200 dpi scan:

http://www.frank-buss.de/tmp/pla-pcb-1200-dpi.jpg

The vias and holes were nearly perfect this time and the board worked without problems, too (at least without problems of the caused by the PCB process, I had to solder some really thin wires because of a design bug I made ).

I guess I was expecting a nasty surprise anyway, since the specifications that they do publish are so poorly specified that I had already spent a good while trying to find things. Still don't know what their silkscreen resolution and registration are...

Besides the silkscreen specification, what do you miss? Looks good for me, they specify anything I want to know, like conductor width and space. They even have a Eagle "rules" file, which makes it very easy for me, because I'm using Eagle. BTW: at least they specify silkscreen line width (min 6 mil).

[ejeffrey]

I see your point, but is I am paying for something, then it must be exactly as I say. They should at least contact the customer and say what their process is, and let the customer decide to go through with it or not. Instead of just opening the delivered package and finding it there.  Bad business in my opinion.

Most pool services are going to add a serial number to your silk screen, especially if you don't have a distinctive identifying mark.  Even relatively high-end places like Euro-Circuits do that.  Your PCB will be combined with many other customers onto a large panel, and the serial number helps them make sure everyone gets the right parts.  With good manufacturers you can ask them not to, or use a double sided silkscreen and put it on the side you don't care about.

[frank26080115]

I was just testing a bit more and found that some traces were not conducting. I'm wondering if it is my fault. But I can fix these with thin wires. The design isn't too complicated, I could've probably deadbugged the whole thing on paper but I figure I experiment with FPC for the first time.

It's my first time doing a flexible circuit, does anybody have any design tips? Any caveats I should watch out for? Are there any bad practices that will make joints or traces easier to crack?

I'm trying to align my parts in a way that helps it bend. I can't think of much else.

Are there special tools I should look into? Obviously my Panavise isn't going to work on this. I can't solder on parts with bottom bosses while on a flat surface.

[SeanB]

Glue the board down to a piece of cardboard with either weak water based glue or a releasable adhesive, then do the exposed side like normal, then wash with water and IPA to release the glue and scrub the underside to get it clean, then do it the same way. Simple to align components so that the shorter side is in line with bending, and for DIP and such packages place a backing FRB board behind it with a permanent adhesive, either as a part of the board or added during assembly.

[free_electron]

First of all : over 40 different projects with iteadstudio , zero problems. Some were 2 layer, some 4, so me were batch orders.

Now, looking at your board : this smells like gerber import problems.
If you look at the pads on the left they have a proper square aperture. The pad with the missing track has a round aperture ( you specified square ). So that is a problem in the gerber data !
The track that is missing seems to be of a specific width not used anywhere else. I may be wrong but it looks wider than the other traces.

As for them needing to put on serial info. Every boardhouse does that. Even the giants that do massproduction. Flip over a pcb on a harddisk and it will tell you the tripod or topsearch logo and batchnumber. No escaping. This is traceability.

As for layout of flex pcb ... Your entire design would be rejected. On flex boards you cannot change dimensions in a step. You need teardrops everywhere. Pad to track or track to track dimension changes need teardrops.
There are also rules for minimum openings in the soldermask. They cant make em smaller than a certain size. Its actually the corners that form a problem. Now that it think of it. That could be the cause of your square openings on those pads being changed to round.... You violate the sharp corner distance rule.

Flex board design is a skill in itself and follows completely different rules than rigid boards.

Now on to the 'itead bashing' : itead does not touch your gerber data. The file goes to the boardhouse they use , those guys slap on the information.

Here is some other bits of i fo : you know how they say : no internal cutouts , no internal milling ? Well i have done at least 5 boards with internal cutouts, oblong holes, non plated oblongs and other 'weird shit' they clearly state they won't do.

Here's the secret : most PCB CAD tools (i won't mention names because that would open another shitstorm... Let's call em tools not even worthy of that name as they are glorified pecil and paper replacements) don't generate the proper gerber constructs or excellon constructs for those jobs. It takes manual intervention to intercept these improper constructions, correct them and hope you have all of them... If you miss one, the customer (who is already a cheapscate) will be yelling at you. As this service is targeted to joe hobbyist (who frequently thinks he is super-layout-man because he can connect two pads together) they impose these restrictions.

They have a business to run. They ar not an education facility nor an intensive care institute for defective layouts.

I always include a mechanical layer that holds the itead order number , sku number , the color of soldermakk and silkscreen. A separate mechanical layer that shows the slots, oblong drill holes (like for those power dc jacks)  and other weird shit , with full dimension arrows. My CAM data is split in folders : gerber , ncdrill plated , ncdrill nonplated and ncdrill plated slots. All milling paths are on an individual layer as well in the gerber.

This folder structure gets zipped in afile with the order number and sku number ( so there is no discussion)

I use this approach with all my board vendors. I've never had problems , neither with US Based very high end makers, nor Eurocircuits , Vermeulen Printservice , ACB or any other european pcb maker.
I also have never had problems with itead. I send them exactly the same output using the same workflow i use for anyone else. This proves that their pcb fab is perfectly capable of doing 'real' work.

I've done 6/6 (6 mil track and gap) boards with itead without a single question from their side. Send the files and 9 to 10 days later i had the boards in house (UPS Shipping)

[amyk]

Lots of good info on how to design with flex here: http://www.pcb3d.com/uploads/Flex_Design_Guidelines.pdf

[peter.mitchell]

I have done 6/6 with Itead too the results were fine, but not internal cutouts ect.

I am curious, have you done internal cutouts that are used for panelization (which they say they don't do)? I noticed the price difference between 5x10 and 10x10 is very small and may be worthwhile doing 2 boards in the 10x10 and breaking them out rather than doing 2 orders of 5x10.

[frank26080115]

Lots of good info on how to design with flex here: http://www.pcb3d.com/uploads/Flex_Design_Guidelines.pdf

Excellent, thanks

First of all : over 40 different projects with iteadstudio , zero problems. Some were 2 layer, some 4, so me were batch orders.

I've used both ITead and Seeed before without problems as well. Like everybody else here, I just wished they (either the store or the manufacture) gave me a "approve this change" email.

most PCB CAD tools (i won't mention names because that would open another shitstorm... Let's call em tools not even worthy of that name as they are glorified pecil and paper replacements)

Do you have any recommendations? I can start using Altium but I don't want to switch my prefered tool unless I really need to.

[c4757p]

I shouldn't criticize people while I'm in a grouchy mood. (Too bad that's when you most want to do it...) I ought to mention the fact that that one thing was my only "bad" experience with them, and even that wasn't really bad, just irritating. I still use them for pretty much everything and they normally do an excellent job. When I'm patient enough to settle for shipping by standard post, they're cheap as all hell, too. I wouldn't hesitate to recommend them for PCBs. (FPCs, maybe. That one really should have been rejected - I agree, looks like a bad design - and that silkscreen just makes me embarrassed for them.)

Now on to the 'itead bashing' : itead does not touch your gerber data. The file goes to the boardhouse they use , those guys slap on the information.

100% true. Counterpoint: They choose the board house and ought to stand by its quality. I don't even know what board house they use, and they don't give me a choice, so as far as I'm concerned it's an "itead board" and if I have a problem with it, they are the closest I can find to someone to hold responsible for it.

I've done 6/6 (6 mil track and gap) boards with itead without a single question from their side.

I hope not! Unlike your slots, that's perfectly within their requirements (0.15mm). I've done 6/6 with them as well.

[c4757p]

Still don't know what their silkscreen resolution and registration are...

Found the resolution! I wonder if they just added it, or if I've been missing it all this time... 6 mil. It's at the bottom of the capabilities table - I swear it wasn't there before...

[free_electron]

I've used both ITead and Seeed before without problems as well. Like everybody else here, I just wished they (either the store or the manufacture) gave me a "approve this change" email.

I would take a hard long look at the gerber data first.... I suspect problems there... And in that case you cant blame itead...

Process the gerber using a real tool and see what happens. (Tools like genesis frontline, lavenir, ucam or cam350. 99% of the boardfabs out there use either ucam or genesis frontline. Those are the gold standards for gerber processing)

[frank26080115]

I would take a hard long look at the gerber data first.... I suspect problems there... And in that case you cant blame itead...

Process the gerber using a real tool and see what happens. (Tools like genesis frontline, lavenir, ucam or cam350. 99% of the boardfabs out there use either ucam or genesis frontline. Those are the gold standards for gerber processing)

I used Gerbv, does that count? UCAM and Genesis are not free.

[Jon Chandler]

I have done 6/6 with Itead too the results were fine, but not internal cutouts ect.

I am curious, have you done internal cutouts that are used for panelization (which they say they don't do)? I noticed the price difference between 5x10 and 10x10 is very small and may be worthwhile doing 2 boards in the 10x10 and breaking them out rather than doing 2 orders of 5x10.

Elecrow has recently announced that they offer panelizing with v-scores for a slight extra charge over the standard prices which are the same as iTead and Seeed.  Elecrow also offers colored soldermask at no additional charge.

I've had one board made by Elecrow and it was of good quality.  I have a panelized board underway so I'll report on the results when it arrives.  I was able to squeeze 8 boards into a 100mm x 100mm panel.  For that many copies, the additional charge was $12, making the total price $36 for 80 boards.

There's a discussion of panelizing options from the Chinese suppliers here.  Some of the suppliers allow multiple boards on the panel at no additional charge, with only the board outlines separating them on the silkscreen.  You have to cut the boards apart, which can be a miserable task.