Saturday, 18 July 2015

Dirty Circuits Done Dirt Cheap


Often design and research is and expensive business, especially when dealing with technology that your are unfamiliar with. A big proportion of this is PCB manufacture and I have spend a few years looking for a low cost reliable method for PCB production.

The most cost effective method is to have the boards produced overseas but then you won't be sure of the quality of the boards until they return. This is where Dirty PCB step in.

Dirty has been setup by the guys at Dangerous Prototypes as a reliable access to PCB fabs overseas.











I discovered Dirty PCB while looking at another PCB manufacturers reviews and recommendation on a forum post.

So went over to there website and I was almost knocked of my feet at how cheap 2 layer PCBs were.


If you can keep your design under 5cm x 5cm and don't mind if you end up with anywhere between 8 - 12 PCBs then it is only $14 (9GBP) that could be less than 0.10GBP   1GBP per PCB. WOW! There is also a selection of colours for the solder masks at no extra cost.

For me that is great for me as most of my designs are under this size as 50x50mm is quite equate for a breakout board but for $11 more you can have up to 10cm x 10cm (100x100mm That's huge). 

There are a few things that you need to accept to get this price level the boards can only be 2 layers and the pad finish will be HASL (Hot Air Solder Leveling) there is an option for ENIG (Electro-less Nickel Immersion Gold) but it is $15 more. Also there free postage option is quite slow so its worth paying $19 more to get DHL airmail, I realise this is more that the PCBs cost but otherwise it could be a up to 8 weeks delivery. 

Next thing to have a look at is there capabilities, this is all listed in the FAQ.

Capabilities
ITEMCAPABILITY
MaterialFR-4 0.6mm-2.0mm 1oz copper ('standard' PCB material is 1.6mm thick, but we default to 1.2mm)
Layer number2L
Maximum size100*100mm (10*10cm)
ShapeAlmost anything! We'll send it and see if they accept it!
Min internal slot32mil (0.8mm)
Min core thickness4mil 0.08mm
Min core thickness16-96mil(inner) 16-118mil(out)
Min w/s5/5mil(I/L)
Min w/s5/5mil(O/L)
Min silkscreen line0.15mm
Min BGA sizeOblong:10*13.5mil/circle:12mil
Min SMD width8mil
Min solder dam3mil(green)/3.5mil(black)
Min dielectric thickness2.5mil
Min diameter of finished hole12mil
Tolerance of drill position+/- 2mil
Tolerance of finished hole sizePTH +/- 3mil
Tolerance of finished hole sizeNPTH: +/- 2mil
PTH hole copper thickness0.6~1.4mil
Max A.R of PTH8:1
Surface copper thickness1oz
Routing dimension tolerance(Z0) Impedance control 4mil
V-cutNow refused! 80*80mm(min) 380*300(max)
(Z0) Impedance control+/- 15%
Ionic contamination< 6.4ugNaCl/inch2
Surface treating(No PB) hot air levelling/AuSn/AgCN/Electrogilding/Ni/OSP*/G.F
*OSPOrganic solder-ability Preservatives
This is much the same as most board houses standard service I'm mainly looking at the trace thickness and clearance which is 4 thou (thousandths of an inch, this is a bit of a legacy thing with board houses) and a clearance of 5 thou.

There is some helpful things further down the page, Dirty PCB supply a design rules check file for Eagle this file is use in you design rules check to make sure your PCB design is manufacturable. They also supply a cam processing file to help export your design manufacture file. But if you use Eagle like I do you can just send in your .brd design file and Dirty PCB will do all the exporting for you. This is great as I don't have to worry about getting the export wrong or sending the wrong layer files.  

So that's it time to give them a spin. Note: Dirty PCB only accept PayPal payments best to make sure you PayPal details are upto date.

On thing I noticed after putting in my order is that the level of communication is amazing are reassuring, and you can also check the status of you order in the websites status page.  

One Week Later (seriously that is really really fast!)


Such Box! Much Cute! 


There is no mistaking this box the end stamp is very cool.


And then you even get a sticker, I like stickers :)


The PCBs where well wrapped but a little loose in the bag the could rub against each other possibly scratch the finish but this didn't happen in my case. 


I always get excited to see one of my own designs as PCB please don't get too excited this is not a product its just a demo board to try out a BLE chip that I might use in a product ;)


The finish is great the Silkscreen is legible and the resist is nice and even. lets have a look under the microscope.


The quality is excellent and precise the soldermask is tight to the pads with none of the ground fill exposed. The thing that really knock me off my feet is they have also managed to apply the mash between the the pads on the main package, these gaps are less than 0.2mm in width that is brilliant.

  
 And for the free sticker.


Got the perfect place for that.

So what do I think of Dirty PCB here is my round up:

  • Easy of use: Straight forward and quite fun the site feels as though it doesn't take itself to seriously and approachable. Though more payment options would be a nice addition.
  • Communication: Reassuringly comprehensive without feeling like I'm being spammed.
  • Lead Time: Quick! 
  • Packaging: Exciting!
  • Finish and Quality: Astounding good.
I can only award Dirty PCBs up to 5 sparks but in may opinion they deserve 6. Very pleased with the service.
  


  





5 comments:

  1. There's a price-comparison calculator for printed circuit boards at PCBShopper.com. It lets you enter your board's specs, then shows you prices from two dozen PCB manufacturers, including DirtyPCBs.

    For 5x5cm boards, DirtyPCBs' price is nothing special - there are 5 Chinese manufacturers that charge $9.99, just like DirtyPCBs. DirtyPCBs looks better if you want a solder mask color other than green (the other Chinese companies charge extra for different colors, but DirtyPCBs does not).

    For boards larger than 5x5cm, DirtyPCBs' price jumps above that of other manufacturers - even if you want colors other than green.

    So I'd recommend checking out the price comparison tool before making a purchase.

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  2. There are other factors which should also be considered..;. PCB quality, delivery time, etc... Getting $9.99 PCBs and having to debug the PCB manufacturing (small shorts to do under etching, etc)... or having to wait a number of weeks for the PCBs may not be for everyone. From the PCB reviews I have read, DirtyPCBs quality is consistently very good and their delivery is also excellent... To me this would take precedence over price.

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    Replies
    1. Kirby, PCBShopper shows delivery time (and even lets you specify when you want your boards to arrive - PCBShopper considers lead times and shipping times to meet your schedule). As for quality, people can read and write Amazon-style reviews of the PCB manufacturers.

      DirtyPCBs is charging $10 for 5x5cm boards. So are several other Chinese manufacturers. DirtyPCBs sends the boards to a Chinese company for manufacturing. I would be surprised if DirtyPCBs has some "secret sauce" that allows them to get vastly better quality at the same price as everyone else.

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    2. I would have to agree with Kirby with this one I checked out a few review of different manufacturers before selecting DirtyPCBs. There are some that the Mask tightness and silk finish is questionable. And I have had issues in the past of bridges it exposed copper fill. NIGHTMARE! Also as mentioned the feel of the service was excellent I felt like a valued customer other then just a number in the cue, saying that, i will checkout that PCBShopper.com an see what it all about :)

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  3. Sorry folk just spotted an error less than £1 per PCB not £0.10 ( order of magnitude fail ) :) AMENDED

    ReplyDelete