EEVblog® Electronics Community Forum
Electronics => Projects, Designs, and Technical Stuff => Topic started by: marshallh on December 08, 2013, 01:31:01 am
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I promised Mitch a writeup on this, so here it is.
OSHPark - 2-4layer batch pooling service, charges by the square inch bounding box of gerbers.
Hackvana - 2-4layer direct ordering service, charges by setup cost + quantity, specs, and area.
Let me start by saying I have ordered many boards from Laen through his oshpark service, and have that service of his to thank for enabling my projects. However there are issues that I and others have experienced that might save somebody else some trouble.
4 layer, 5mil track/space, 10mil minimum drill.
Screenshot of the 0.8mm BGA which is why I need 10mil drill.
(http://retroactive.be/lsu3_001_altium.png)
Drill export report
Tool Hole Size Hole Type Hole Count Plated Tool Travel
---------------------------------------------------------------------------
T1 10mil (0.254mm) Round 869 57.37 Inch (1457.13 mm)
T2 12.99mil (0.32995mm) Round 4 0.14 Inch (3.60 mm)
T3 13mil (0.3302mm) Round 16 0.63 Inch (16.00 mm)
T4 27.56mil (0.70002mm) Round 5 0.33 Inch (8.50 mm)
T5 35.43mil (0.89992mm) Round 10 0.90 Inch (22.86 mm)
T6 36.22mil (0.91999mm) Round 4 0.28 Inch (7.00 mm)
T7 76mil (1.9304mm) Round 3 0.34 Inch (8.60 mm)
T8 86.61mil (2.19989mm) Round 2 0.39 Inch (9.90 mm)
T9 90.55mil (2.29997mm) Round 2 0.47 Inch (12.04 mm)
T10 100.39mil (2.54991mm) Round 1 0.00 Inch (0.00 mm)
T11 125.2mil (3.18008mm) Round 4 7.47 Inch (189.81 mm)
---------------------------------------------------------------------------
Totals 920 68.32 Inch (1735.45 mm)
Sep 29 - Run 1 ordered. $75
Oct 11 - Run 1 shipped.
(http://retroactive.be/lsu3_001_run1.jpg)
(http://retroactive.be/lsu3_001_run1_zoom.jpg)
Minor plating failures, maybe salvageable if all pads had oxidation removed immediately before reflow. However all 10mil hits were upsized to 13/14mil by the fab, resulting in catastrophic breakout. Inner 16 power vias are 13/21mil and were not negatively affected.
Oct 15 - Run 2 ordered. Complementary re-run after talking to Laen (Thanks)
Oct 25 - Run 2 shipped.
(http://retroactive.be/lsu3_001_run2.jpg)
(http://retroactive.be/lsu3_001_run2_zoom.jpg)
Plating failures, severe overetch and again overdrill.
My project needed to progress and it looked unlikely that I would be able to get it done at all.
Enter hackvana. Mitch is an Australian fellow that travels to Shenzhen and works directly with a board shop there. He does not pool batch orders like Oshpark. This means the minimum order is 5 pcs and you pay all the setup costs. At this point I was more interested in getting a working PCB.
Quote from Mitch was $123 plus shipping. Turn time was about 9 days.
(http://retroactive.be/lsu3_001_runh.jpg)
(http://retroactive.be/lsu3_001_runh_zoom.jpg)
Great plating, proper 10mil drills, adequate silk and soldermask. The only beef I had is that the fab grew the copper layers by about 2mil to prevent drill breakout. This is a pretty common chinese fab trick. Mitch says this can be bypassed if needed (obv. for stuff like controlled impedance diff pairs). It does not create any shorts but does mess with track impedance. E-testing is claimed but I do not see any probe marks or evidence of testing.
In any case I assembled the PCB and it brought up OK.
(http://retroactive.be/lsu3_001_assemble.jpg)
Back to OSHPark -----
Nov 7 - Run 3 Oshpark started (Again complementary after talking to Dan and describing the issues, he said it would be addressed)
Dec 2 - Run 3 shipped.
(http://retroactive.be/lsu3_001_run3_zoom.jpg)
Plating and drill alignment is finally addressed. Drills are still upsized and causing severe breakout.
OSHPark uses about 3-4 different fabs for the 4layer batch. Whichever one you get is up to the phase of the moon. Each one is identifiable due to characteristics like LPI silk, copper overetch, low DPI silk, etc...
The moral of the story: Don't use 10 mil drills with them, and prepare for delays. Plating fails have happened before, a friend wrote up a failure analysis with SEM imagery and sent to the fab. That fab is still experience plating failures and still being used by the service.
One such failure courtesy azonenberg
(http://retroactive.be/azon_oshfail.jpg)
SEM comparison of plating (good is first, bad is second)
(http://retroactive.be/azon_oshfail2.jpg)
You can read his full failure analysis pdf here (http://colossus.cs.rpi.edu/pictures/2013/April/4-13-2013%20-%20plating%20FA/oshpark_plating_wWuhtxPc.pdf)
Laen and Dan of OSHPark are both great guys and a pleasure to talk to. I will still order 4layer pcbs in the future, but not important ones.
Mitch of Hackvana can also be talked to directly via email or IRC. I will be ordering from him in the future as well.
I hope this was objective and gave you an idea of what to expect from these two services.
Links -
OSHPark http://oshpark.com/ (http://oshpark.com/)
Hackvana http://www.hackvana.com (http://www.hackvana.com) https://docs.google.com/document/d/1p6FH25ltGpzJQ5_8fbflDukqEKghiEcpuhJpngth2Is/edit (https://docs.google.com/document/d/1p6FH25ltGpzJQ5_8fbflDukqEKghiEcpuhJpngth2Is/edit)
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Hello folks,
I'm Mitch, yes Mr. Hackvana.
marshallh, thank you very much for your kind words.
I have the best job in the world. I get to see amazing designs like this one, and I get the glowing feeling of helping people make things.
Being the centre of the largest electronics manufacturing district in the world, Shenzhen has everything you need to turn an idea into reality. I've lived there for several years and I love it. The language barrier is enormous though.
There are several fabs I use, depending on the job. I know the people at each one personally, and I know they'll do a good job. I see my role as helping you guys get access to these wonderful places, while taking care of shipping, payment, the language barrier, and most importantly, fixing things if they go wrong.
My IRC channel (#hackvana on Freenode):
http://webchat.freenode.net/?channels=hackvana (http://webchat.freenode.net/?channels=hackvana)
Good place to talk about electronics, as well as ask me questions.
Finally I want to say sorry oshpark didn't work out for that board. Laen is a big inspiration for me, and I think what he's done for hackers over the years has been huge. If you're in the USA (or you just want to support a guy whose done so much for hackers), get your boards from OSH Park ^-^
Mitch.
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The edge connector fingers on the hackvana board look a bit corroded, maybe from handling. Is this just the standard enig for a prototype or is it a special (thicker) hard gold plating as done by some shops?
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If you don't mind saying what that is? Building your own PCI-E gigabit Ethernet adapter? ???
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The edge connector was not electroplated. There is some scuffing due to the shop running the boards through the edge beveler.
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If you don't mind saying what that is? Building your own PCI-E gigabit Ethernet adapter? ???
It's not an ethernet connector. It has a USB and some type of power connector... I'm curious too.
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usb 3.0 engine obviously
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obviously
Not obvious. Not to everyone, anyway.
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One comment about the electrical testing - I have had boards which failed the E-test (they still sent them to me, as well as the second batch) and had no evidence of having been tested. Some of the fabs must have very gentle testers (or do it before HASL?)
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obviously
Not obvious. Not to everyone, anyway.
really ? the usb connector with 6 extra pins and the matched length differential pairs are a dead giveaway.
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really ? the usb connector with 6 extra pins and the matched length differential pairs are a dead giveaway.
Dead giveaway to you. Lots of us don't look at this stuff every day, like you. I'm just starting in this hobby, and I had no idea what that board was until you posted what it was.
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You've never used USB 3.0 before? The blue on the connector was the dead giveaway for me. They're all that particular blue colour.
(Plus the silkscreen USB symbol helps too)
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You've never used USB 3.0 before? The blue on the connector was the dead giveaway for me. They're all that particular blue colour.
(Plus the silkscreen USB symbol helps too)
I still don't personally own a machine with USB 3.
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... :-//
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... :-//
Some of us buy good hardware and just can't afford to every other year when the latest fancy toy comes out...
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What do most people even use USB 3.0 for? :-//
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lol wow. You think I can afford anything at all? I've got I think 1 USB3.0 port. I was shrugging because I didn't know what to say to what you said. Don't get so bent out of shape.
I use it for my external hard drive. I can copy over a 6GB file in a minute or two. USB2.0 would take most of an hour. 2.0 is becoming extremely obsolete, very quickly. I'm just as behind as anyone else.
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How many 6GB files do you copy? :o
I don't think I've ever used a USB 2 device and thought "damn, this should be faster"!
Anyway..... back to PCBs?
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Quite a few, you don't watch TV shows or movies? I download just about everything onto a 2TB external hard drive. Makes it nice and portable.
Anyway, we're way OT here.
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I still don't personally own a machine with USB 3.
Your computer needs to get out more often. That aside, the usb connector, the color and the squiggly lines kinda gave it away. And oh I dunno the big fat TUSB1310A transceiver right next to it. ;D
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I still don't personally own a machine with USB 3.
Your computer needs to get out more often.
My wallet needs to get laid more often.
That aside, the usb connector, the color and the squiggly lines kinda gave it away. And oh I dunno the big fat TUSB1310A transceiver right next to it. ;D
Never said I didn't know it was a USB 3 port. ;)
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What do most people even use USB 3.0 for? :-//
External drives for a cheapo backup solution. Doesn't get you the same iops and latency as sata, but throughput is pretty good. All I need for said cheapo backup solution. Get two 3 Tb disks at your local friendly Aldi and you're good to go.
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I still don't personally own a machine with USB 3.
Your computer needs to get out more often.
My wallet needs to get laid more often.
Amen brother. Or am I now anthropomorphizing m4 w4ll3t? Damn...
That aside, the usb connector, the color and the squiggly lines kinda gave it away. And oh I dunno the big fat TUSB1310A transceiver right next to it. ;D
Never said I didn't know it was a USB 3 port. ;)
Never said I didn't know that you did or didn't know that it was or was not a USB3 port (or not). In fact, I didn't even imply that you did or didn't know that it was or was not a USB3 port. Or did I ... ? ;)
no I didn't
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External drives for a cheapo backup solution. Doesn't get you the same iops and latency as sata, but throughput is pretty good. All I need for said cheapo backup solution. Get two 3 Tb disks at your local friendly Aldi and you're good to go.
Aldi sells HDDs where you live? Here, it just sells the sort of food that you eat while reading job listings and crying.
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Aldi sells HDDs where you live? Here, it just sells the sort of food that you eat while reading job listings and crying.
Yup, HDDs. Good coffee too. Quite decent wine as well but that takes a little timing. So I'm guessing this is a distance-to-Heimat thing. Apparently in a US Aldi you can get cryworthy food. In a dutch Aldi you can get good coffee, well timed wine and cheapo HDDs. And back in Germany you can probably walk into an Aldi store and get a Rheinmetall transfunktionierter cyberblaster bollocks Kanone on discount.
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:)
My grandfather used to cook and eat squirrels that he killed in the yard because he was too cheap (not poor - cheap) to buy proper meat at the store. I am not kidding, exaggerating or bullshitting. He shops at Aldi.
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Trader Joe's is owned by the same dudes that own ALDI ...
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Who is aldi and why do they sell harddrives and food? seems like an odd combination...
Also, on topic, that annular ring break out makes me cringe just looking at it.
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I bought a printer/scanner/faxer there last week :)
Not with USB3 though...
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Also, on topic, that annular ring break out makes me cringe just looking at it.
I've only done a couple boards with OSH, but that's basically what I found too. Impressively bad drill registration and it seemed like they up-sized the holes a bit too. IMHO they should list the drill diameter tolerance, and I think their annular ring spec is a bit optimistic...
The purple+gold is sexy though. ;D Though I am a bit of a purist, I think a green soldermask (especially the duller ones like we've seen on some of the Rigol teardowns &c) looks very professional. I like the USB board better in green.
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Who is aldi and why do they sell harddrives and food? seems like an odd combination...
Also, on topic, that annular ring break out makes me cringe just looking at it.
I'm pretty sure that Aldi in the US differs from Aldi outside the US.
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Despite Laen being a great guy to deal with, I had poor success with OSH.
The drill sizes ended up smaller by over the 8 thou spec.- leads did not fit :(
I suspect they round off the drill sizes or assume they are unfinished. I was offered a free re-do but didn't bother as I had a few of my own footprints wrong.
Also, the PCB's soldermask gets ruined by isopropyl alcohol, which I use to clean boards.
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PCB's soldermask gets ruined by isopropyl alcohol
That's weird, I've never encountered any problem with OSHPark before when using isopropanol to clean boards, or acetone for those really hard baked-on flux spots, or DeFlux-It G2, or any other solvent I use. I've never had any problems with soldermask from Hackvana or any other PCB fab I've ever used in this regard either.
The OP's board layout with the FPGA and other BGA devices is beautiful work.
However, realistically, it's right at the upper end of what the PCB fabs targeting the cheap hobbyist market will expect to see in terms of the design rules that are demanded by their customers designs. Designs like yours demanding those tight design rules probably account for few of their customers.
It's nice to know that Mitch can deliver that sort of design rules when I need it. Although I've never needed to use a BGA like that before.
Ultimately what you want from any PCB fab is to have the right expectations about design rules. It's best if they specify we can do X design rules, or we can do Y design rules if you really need to but it's more expensive, and then they actually deliver a working PCB that meets those design rules, without drill breakout or shorts.
If their advertised specification is that they can only do 6/6 copper, or they can only do 13 thou drills, or something like that, then I don't mind, as long as they reliably deliver what they specify. If I know in advance that my board needs to go to another fab in order to get reliable results for a given design, then that's good, that saves time, please don't bullshit me, and I'm more likely to come back to you as a customer in the future for the majority of my designs where 6/6 and 13 thou drills are perfectly sufficient in most cases.
If they fail to meet their advertised design rules, or they go and edit the files you've given them and change the 10 thou drills to 13 thou then that would piss me off. Generally speaking, any PCB fab just going and changing the files you've given them without any discussion or understanding is behavior I would really not be happy with.
OSHPark purple is beautiful, I think it's great, but unfortunately OSHPark seems to be one of the only places in the world where you can get that purple solder mask. (But this is a personal preference obviously.) I wish you could get something similar from other fabs.
But obviously good old green is good for most prototypes, too :)
Of course the tradeoff with OSHPark is that you only get the purple/ENIG, if you want something else you don't get a choice.
One tiny, trivial fussy thing about Hackvana is that they will add their internal job identifier/serial number printed on the silkscreen on your boards. On the OP's sexy USB card, for example, you can see this is on the silkscreen underneath the RAM chip on the Hackvana board but not on the OSHPark board. Mitch and his team will usually move this text, where possible, so that it is hidden underneath a component when the board is assembled. This is pretty trivial, but you may dislike it if you are very fussy about the aesthetics of your silkscreen text and there are no components on the board suitable for hiding space, and usually other places (including OSHPark) will not include such text.
Personally I find that OSHPark is a bit slow, taking almost 1 month to delivery from when I place my order. I suspect this is a combination of a couple of factors, namely living in Australia as well as always choosing the most tight-ass postage option. If I paid for proper delivery it might be a bit better. Hackvana is superior in this regard, but for those of you living in the US then OSHPark might be faster.
I do like the OSHPark pricing model, though, with no setup fees. Many PCB fabs like to go for the "super size deal", where, you know, you're getting that economy of scale and you're only paying 50% more for a 200% increase in your number of boards, or something like that. But I don't always care about that.
Sometimes I want to test a risky design experiment, or prototype or test a subsystem, something that is a work in progress with lots of design revisions and changes being prototyped, so I'm only ever going to need 2 or 3 boards and I have no use at all for 10 or 20 boards. So I can go to OSHPark and get their 3-board batch for a very low price, say $10-$15 depending on the board size, and this is very attractive to a cash flow constrained self-employed engineer, allowing a design revision, or a part of the design, to be physically built and proven and debugged with minimal expenditure, ready for the next design revision. This is very attractive where you need 2-3 boards, and have no need at all for 20-30.
OSHPark provides stackup details, which is important for controlled-impedance designs. So it's good that they actually provide that.
http://support.oshpark.com/support/articles/136707-2-layer-board-stackup (http://support.oshpark.com/support/articles/136707-2-layer-board-stackup)
http://blog.oshpark.com/kb/4-layer-stackup/ (http://blog.oshpark.com/kb/4-layer-stackup/)
Obviously any serious controlled impedance design, whether for RF or fast digital, is likely to require careful testing and refinement of the board design and the use of techniques like making a test token with just a straight-through transmission line on that stackup from that PCB fab... but if the PCB fab can't start by specifiying the stackup and the type of dielectric they're using then it's a waste of time, it's not plausible to consider making a design that they can manufacture. In some cases you may need to either go to a different board house, or change the transmission line widths to get the impedance right for a given board house, or do an empirical test board with that board fab and measure its impedance and tweak accordingly.
Another minor disadvantage with OSHPark, personally, is they leave those jagged ugly snap-off tabs on the edge of their boards. Yes you can file them off, but I find this a bit of an annoying messy feature, from the way they panelise their boards. Most PCB fabs, including Hackvana, will provide you with a nice clean milled edge as your design specifies, but OSHPark fails in this regard.
I've never found any "perfect" PCB fab house that delivers everything exactly the way I want it with all the right manufacturing specifications and reliable adherence to those specs, with relatively fast turnaround, at a relatively good price. I can name slight gripes (very trivial in some cases) about any of the several places I've worked with.
But both Hackvana and OSHPark are pretty good overall.
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I used IPA on one of my oshpark boards yesterday and the silkscreen is still perfect.
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I have had one order from OSH Park last year where silkscreen was easily removable with IPA/toothbrush combo. Others were good, including the most recent one.