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PCB Software

Discussion in 'Circuit Simulation & PCB Design' started by ronv, Jun 8, 2014.

  1. MrDEB

    MrDEB Active Member

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    I saw where Hack-A- Day suggested trying the Dirt Cheap boards. Hopefully they will work better than the last batch I got from Elcrow which had several shorts . Have used Iteasd and happy w/ results but couldn't pass up the $14 plus free shipping. Yea I mifght pay more for cheap but the ICSP expander is a really simple board. Will wait and see. Thanks for the link but I had seen that before.
     
  2. JonSea

    JonSea Well-Known Member

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    I have had nothing be excellent results from Elecrow with about 10 different boards ordered to date.

    Was it a manufacturing problem, which they will fix, or a layout error?
     
  3. MrDEB

    MrDEB Active Member

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    I have checked and rechecked using a ohm meter but all the circuits are connected but need to recheck for shorts between connections. The layout looks fine and the 8 x 8 matrix works but I lose the last two lines of the matrix. Assembled several boards with same results.Got frustrated and put it aside but feel the circuit board may be at fault??
    When I get my boards from Dirt Cheap I am going over them with a fine tooth comb before assembly.
     
  4. dave

    Dave New Member

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  5. JonSea

    JonSea Well-Known Member

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    Wow. When I have a board that doesn't work, I first suspect errors on my part. I would never accuse a fab house of shoddy work until I positively located faults of their doing. You could seriously damage their business with careless remarks like this.
     
  6. JonSea

    JonSea Well-Known Member

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    1. Your circuit design may be in error. There are many connections to the matrix, so this is a likihood.

    2. Your implementation of the circuit to PCB layout may be in error. It's easy to inadvertently swap connections for example.

    3. Your circuit board layout may have errors like crossed tracks, missed connections, traces too close together, etc. I don't know if DipsTrace has a DRC, what parameters you have set or if you even use it. Many errors will be detected if you use a properly configured DRC.

    Do you use a service like FreeDFM.com? You submit your Gerber files and a few minutes later, you'll get a report of any errors in your Gerber files. It won't detect errors in the circuit, but it will find problems in the Gerber files and tell you if they can be manufactured.

    To say "the boards have several shorts." followed by "My circuit doesn't work. I feel the boards may be at fault?" is irresponsible. Unless you can show faults in the boards that aren't a result of the files you submitted, you shouldn't say the boards are faulty. Someone unfamiliar with your talents may read your first comment and conclude the vendor doesn't do quality work.

    Errors do happen. Years ago I received a board with shorts. There was a small triangle of copper shorting two traces, which was not present in the Gerber files. Somehow when the film was made from the Gerbers had a triangular shape added. When the fab house was shown the boards and the Gerbers, they saw the error and made the boards again.

    Other errors have been entirely my fault; a ground plane split into two, missing connections, wrong footprints. Nobody but me to blame for those errors.
     
    • Like Like x 1
  7. eTech

    eTech Active Member

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    Hi

    There is a free DFM too called DFMNow that is a gerber viewer and DFM checker. Works great.
    I use it before submitting gerber data for PCB fabrication.

    eT
     
  8. MrDEB

    MrDEB Active Member

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    Diptrace has a DRC checker and all is good. Even compared to schematic and everything is OK.. I got curious about why the dang thing loses three lines of the Matrix (one line stays on).
    Did some further checking with components mounted and a bare board. Found I had one of the 805 smd resistor pads grounded on a bare board.going to investigate if I can increase the distance around the smd pads to copper fill. Contemplating submitting board again but rechecking using the freeDFM.com link.
    Live and learn
     
  9. JonSea

    JonSea Well-Known Member

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    So just to clarify, Elecrow supplied the boards as ordered, without any shorts?

    Don't you see that your "...the last batch I got from Elcrow which had several shorts." declaration could cost Elecrow business? If I didn't know the company, that would make me hesitant to use them. But as I said, I've ordered about about 10 different boards from them and all have been well made.
     
  10. MrDEB

    MrDEB Active Member

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    I have two different boards I had Elcrow make with no problems. I see no real difference from Itead and Elcrow. Now for a really nice board I have 3 I had Dorkboards or ? made. Gold finish on pads, board is purple. Really nice but not if wanting more than a proto- type board.
    Would I order from Elcrow again? YES. I like the communication that they provided as the board is being processed.They even sent me an email w/ picture before shipping boards. Nobody is perfect, in fact I might order this 8 x 8 matrix board from them again. Pouring over my pcboard design to increase the area around the 805smd resistors.
     
  11. JonSea

    JonSea Well-Known Member

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    Sigh. It still sounds like you're saying it was their screwup, not your poor layout.

    I give up.
     
  12. Semaphöre

    Semaphöre New Member

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    I've used BatchPCB and Seeedstudio's Fusion PCB service before. Both sent me perfect 2-layer boards, though the turn-around time is usually >= 1 month. Are the other ones like Elcrow any faster?
     
  13. JonSea

    JonSea Well-Known Member

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    Elecrow has about a five day turn, and cheap shipping can take a week or two to the US as long as no Chinese holidays get in the way.

    If you're ordering several boards at once, DHL shipping isn't that much of a premium, and I've had boards in a week to 10 days after submitting files. Chinese holidays interfere with DHL shipping too.

    I've made a number of orders with Elecrow now, for about 10 boards and I'm extremely pleased with the results. V-score is available at Elecrow too, which is unique among low-cost providers. One of the attached photos shows a v-scored panel that can be snapped apart into several boards.

    image.jpg

    image.jpg
     
  14. JonSea

    JonSea Well-Known Member

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    One thing that helps to get your boards faster is a good submittal – all the right files, details spelled out. I think Elecrow has their own DRC and CAM files for Eagle now. I use Seeed's DRC and CAM files (which has similar capacities and the same file-naming conventions) with one change – I add the board outline to every layer, and include a note stating this.

    If there's anything not clear with your Gerber files, missing files, etc, it can really slow the process down. Due to time differences, every email exchange can add a day to the process!


    Elecrow has a lot of nice parts and accessories too. With every board order, I stock up on other goodies too.
     
  15. tvtech

    tvtech Well-Known Member Most Helpful Member

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    Nice boards Jon....especially the one in the top photo.

    I use a local Boardhouse here that also delivers excellent product and always on time. Give Gerber and Drill files that are 100% and there is no confusion.

    They link you to GC-Prevue.....which they also use....so both parties are are on the same page:

    http://www.graphicode.com/GC-Prevue

    Regards,
    tvtech
     
    Last edited: Jun 16, 2014
  16. JonSea

    JonSea Well-Known Member

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    Thanks.

    The only problem I've had with Elecrow (I think is was them) having an issue about the board outline, which was shown on one or two layers only, and somehow they missed it (a format that had worked a good many times before with many vendors including them), so now I include it on every layer along with a note just to be sure.

    Here's an example of my typical ReadMe.txt file:

    AS1106-LED-DISPLAY

    Size: 98.1mm x 60mm
    2 Layers
    Silscreen on top and bottom
    Soldermask top and bottom

    Board outline is included on all layers.

    Layers

    AS1106-LED-DISPLAY.GTL - top copper
    AS1106-LED-DISPLAY.GTO - top silkscreen
    AS1106-LED-DISPLAY.GTS - top soldermask

    AS1106-LED-DISPLAY.GBL - bottom copper
    AS1106-LED-DISPLAY.CBO - bottom silkscreen
    AS1106-LED-DISPLAY.GBS - bottom soldermask

    AS1106-LED-DISPLAY.TXT - Excellon Drill File

    Jon Chandler
    (Email address here)
     
  17. MrDEB

    MrDEB Active Member

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    So your preference is Elcrow over Itead? I recall you used Itead for your Tap-28 boards.
    I like the V-score option but is it cheaper than say having 10 - 5mm x 5mm boards verses 1 -10mm x 5mm.
     
  18. JonSea

    JonSea Well-Known Member

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    No MrDEB. As I have explained numerous times, when I designed the TAP-28 board, the likes of Seeed, iTead and Elecrow didn't exist. The cheapest options for a small quantity of boards were in the $10 - $15 range per board. The only way to get cheaper boards was to order in large quantity. I think for my first lot of boards, I had to order about 24 to get the price down to the $5 range and the second lot was an order for 150 that got the price down to about $3 - $4 each. This lead to the decision to make the boards available to others at a reasonable price; I got cheap boards and everybody shared the wealth.

    The situation has completely changed in the last few years. I can buy 10 boards the size of a TAP-28 board for $15...and so can anybody else. There's little incentive to order larger quantities and little incentive to making boards available to others. I spent a great deal of time creating documentation for the TAP-28 boards that I wouldn't have had to do for my own use, so there really wasn't much payoff for the boards aside from cheap boards for myself and seeing others put them to some cool uses.


    I have used iTead, Seeed, Elecrow and many other fab houses. Elecrow is unique in offering V-score, produces good boards and has good prices - they suit my needs at the moment.

    PCB Fabrication Sources is a good reference for places I have used or am very familiar with. The comments are fairly up to date in pricing and services but changes are continually being made so check with each vendor before making a decision on which fab house to use.


    MrDEB, your comments still make it sound like Elecrow screwed up your boards, but reading between the lines, the problem is a poor layout, correct? Not enough clearance between pads and ground plane, which is your fault, not theirs. I hate to see them lose business because of your unclear remarks.
     
  19. JonSea

    JonSea Well-Known Member

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    From MrDEB's less-than-clear comments about his board with shorts, it sounds like he has a problem with the clearance between a ground plane and traces/pads. In Eagle, this is called the isolation distance; I believe DipsTrace calls this clearance. This is a parameter, much like line width, that must be set.

    The pictures below are from Eagle and show the top and bottom views of the board I posted above. The blue layer is the bottom of the board with a ground plane fill.

    The first blue layer illustrates the board as built, with a 12 mil isolate distance.

    The second blue layer illustrates an isolate distance of zero. The ground plane touches the pads and traces. This is the Eagle default, so clearly, you must set the desired value.

    The last blue layer illustrates an isolate distance of 24 mils. Lots of clearance between the ground plane and traces/pads, but look at the 3 dip footprints – there's not enough space between the pads to connect the ground plane between them. Depending on the board layout, this may result in breaks in the gound plane (voice of experience here).

    When selecting the isolate distance, there's a trade off between clearance to the pads and ease of soldering and the ability of the ground plane to flow around components. Fab houses now often claim a 6 mil trace/space capability (the minimum trace width or space between traces) but it's best not to push the limits when there is no need. I usually use a 12 mil or even 16 mil isolate distance to prevent problems; if high voltage or high current traces are present, give them even more clearance.

    image.jpg
     
  20. Bob Alexander

    Bob Alexander New Member

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    There's a site that can help you choose which free PCB CAD software to use and which PCB manufacturer to use.

    PCBShopper.com has a list of free CAD software on it. Since many of the programs are crippled versions of expensive commercial software (e.g. Eagle) it tells you what limitations the vendor has imposed.

    When you're ready to order PCBs, PCBShopper.com has a form where you enter the size, layers, preferred color, and quantity of boards. It then gives you a list of manufacturers with their prices (including shipping) and the time it will take to get your boards. You can sort the table by price or time to find the cheapest or fastest. There are also some customer reviews of the manufacturers to help you evaluate their quality. You're welcome to write your own reviews of manufacturers you have experience with.

    I created PCBShopper because I'm an electronics hobbyist and I found myself spending far too much time shopping around for cheap board houses. I make a very small amount of money from the ads on the site, but I consider this a hobbyist project that's impartial and independent of any PCB manufacturer or CAD software vendor. I hope my fellow hobbyists will find it useful too.
     
    Last edited: Jun 22, 2014
  21. tvtech

    tvtech Well-Known Member Most Helpful Member

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    WOW. Now that is a very informative first post. Welcome to ETO :)

    So glad to have you post sensible stuff/info here.

    All the best,
    tvtech
     

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