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Help with etch mask

Discussion in 'General Electronics Discussion' started by bigone5500, Sep 28, 2015.

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  1. bigone5500

    bigone5500

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    Apr 9, 2014
    I am using Fritzing to design circuits. I am trying to use Eagle but it is hard for me to get anything done with it. I get my board looking great on the screen but when I print the etch mask, I don't get the 'reverse' I need to use the dry film I have. The program must be assuming I am going to use the toner transfer type method. How can I print my files in 'negative' so the mask comes out right?
     
  2. 73's de Edd

    73's de Edd

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    Aug 21, 2015
    Sir bigone5500

    Do you have either a PDF-GIF-or BitMap format of your final 1:1 board layout images draft, and can you pass it to me at [email protected] and I will see if I canwork back and forth with you on its solution.
    (delete prefix of . . . . . Iamdatdern )

    73's de Edd
     
  3. bigone5500

    bigone5500

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    Apr 9, 2014
    *edit*

    I created the project again and thought it looked right. I was wrong. It still thinks I am using toner transfer method. I will post the files.

    The file I am using is etch copper bottom mirror.
     

    Attached Files:

    Last edited: Sep 30, 2015
  4. Harald Kapp

    Harald Kapp Moderator Moderator

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    Nov 17, 2011
    In the Eagle print menu there should be a checkbox "mirror" (under "style") to reverse the output.
    Or do you mean white traces and black etched areas? As far I can see in the Eagle support forum there is no such option. It is recommended to use the CAM processor with postscript_inverted option. Deselect "fill pads" (may have a different translationin the english Eagle program version) to keep the hole for centering the drill.
     
  5. bigone5500

    bigone5500

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    Apr 9, 2014
    I will have to create the file in Eagle from scratch I assume.
     
  6. bigone5500

    bigone5500

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    Apr 9, 2014
    I am not using Eagle as I have yet to figure out how to add components such as electrolytic caps and so on. It's a good program but I can't figure it out. When you look at the pdf file I mention, the black and white areas should be swapped. That way when I etch I am etching away the copper around the traces and ground plane.

    *edit*
    I'm going to learn this Eagle thing...it will not conquer me!!!!!
     
    Last edited: Sep 30, 2015
  7. bigone5500

    bigone5500

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    Apr 9, 2014
    By any chance could you create my project in Eagle then upload the finished one so I can see how you did it. It may help me learn the program better.

    Thanks.
     
  8. 73's de Edd

    73's de Edd

    2,920
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    Aug 21, 2015
    .


    Sir bigone5500 . . . . .

    In reviewing your files. I just took them and "cut and pasted" them into a graphics editor, with my option of
    using Infaview or Paint. Since Paint is already in just about EVERY computer, I used that.
    Once it is displayed, you then single right mouse click on the image and, by use of the very bottom option of the dropdown menu,
    it will instantly reverse your black and whites. Like . . . . .BAMMMMMM.
    Then you copy and carry on back to your preferred storage medium.

    Since you composed this at 893% (so says the PDF info) you have a literal TON of pixels for super definition, and it can then be
    shifted on down to a 1:1sizing in FINE order.

    Your first two pics had some eight or so stray single lines across them and some abberations, but I corrected those images.
    I left a little excess coverage around your single perimeter line .

    I also couldn't confirm the up is down, down is up and right is left, left is right aspects. . . but it looks like a 7800 series regulator IC layout and its associated bypass, filtering and decoupling caps, folded and vertically mounted.

    Here is the result:
    (If you want to use them, just do a Prt Scrn capture of the image and then separate /paste them into your storage choice.)
    [​IMG]



    ALSO . . . . just in case the above does not mag up adequately/correctly . . . . here is direct contact to image site

    http://i.imgur.com/KaaFN5l.png


    73's de Edd


    .
     
  9. bigone5500

    bigone5500

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    Apr 9, 2014
    Thanks sir! I'm not sure why it would say 893%. I just exported for production and when I view them on my pc it looks like the size I need. When I print them, they print to the exact size I want and the mask fits the board. I want to try the image editor so I will export a png image of the masks directly from Fritzing and see what I can come up with. *edit* I can't export images of my pcb like I want. Will have to try it the other way.

    Thanks a bunch for your help! You are right about the chip. It is a KA7805R 5V regulator, D-PAK. The circuit has two filter caps and the other connection is a two pin female header. I would use surface mount caps but I don't have any. I am doing this so I can get some experience with my equipment/supplies before I try to tackle something large and more expensive. I don't like to mess up much but if I do, I don't want it costing me a lot of time and frustration.
     
  10. bigone5500

    bigone5500

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    Apr 9, 2014
    I used the snapshot action in Adobe acrobat and then pasted the image in Gimp. I used the invert command in the image menu to invert the colors and as you say, BAMMMMM! Thanks for helping me figure this out Edd.

    5V PSU Corrected.png
     
    Last edited: Oct 1, 2015
  11. bigone5500

    bigone5500

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    Apr 9, 2014
    Well... less than desirable results. I think I need a better way to remove the photoresist after exposure to UV. There was still some left that I could not see. I need a better solution for this.

    20151001_210922-1.jpg
     
  12. 73's de Edd

    73's de Edd

    2,920
    1,235
    Aug 21, 2015
    .




    Sir bigone5500 . . . . . .

    Gone with the Wind . . . . Hattie Mc Daniels . . . .

    " Mistah big ones . . . . I don't knowse nuttin' 'bout birthin' no babies . . .but it sho' looks like dat dere pee cee bode shoulds have stayed in the birthin canal 'bouts another fo' months. "


    As per the supplied photos relative comparisons . . . . it should have come out like the one just below it.. . . .
    right ?

    You were just starting to get a full etch through on, in the marked YELLOW dotted areas.

    And is that PCB internal blank being BLACK ? and I can see the Blue-Indigo resist, and of course you really were not ready yet for resist stripping, but mine readily responds to being cleaned off with acetone, toluene, xylene or MEK.

    Also, is the PCB copper double or single sided and of 1 oz or 2 oz weight.
    And is the etching solution being ferric chloride ?
    Was the etching solution heated up ? if so, to what temp.

    My first PCB's were made back in '61 when the trace path norms were .05-.1-.15 and .2 of an inch.

    Nowadays you can even go down and measure in multiples of a hairs width !

    Want any feedback in my fifty fo' years of procedures?

    [​IMG]





    73's de Edd



    .
     
  13. bigone5500

    bigone5500

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    Apr 9, 2014
    This PCB is single sided and I don't' know much more about it other than it is FR4. The internal is a light brownish color. I took the photo with flash in a dark room and that's why it looks like that. I think I can try to clean away more of the etch mask and try to etch again. As far as the resist stripping goes, I saw a video that you apply the resist film and send it through the laminator a couple times and then expose it to UV. You then peel off the top plastic layer of clear film then use a developer of which I landed on Purex washing crystals. This is because they contain the same ingredients that the video said you needed which is Sodium Carbonate. I am thinking I need something else that is more efficient and can strip the unexposed film away. I also assume I am understanding the process correctly. If there is something in these steps I am doing wrong or can change please let me know.

    Thanks for all the help!

    *edit*
    By the way. Am I leaving too much roughness in my copper layer? Should it be smoother?
     
  14. bigone5500

    bigone5500

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    Apr 9, 2014
    So the etchant solution I was using must be too weak. Either that or it is just not going to work. After serveral minutes and multiple tries with the muriatic/peroxide mix, I poured in a very small amount of ferric chloride and within 30 minutes it was almost all the way etched. Sometimes DIY is not so good. I will finish etching sometime today and get some photos.
     
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