negative artwork

Community PCB Design
1

I’m playing around with dry film photo resist. It looks promising but I’ve run into a snag. It’s a negative photo resist so I need to print my artwork as a negative. Eagle doesn’t support this and I’m having trouble finding a way to print the gerber as a negative. I’ve tried exporting the artwork from eagle as a bmp. I have several tools that can produce a negative but printing it out doesn’t exactly match the dimensions of the board. It’s far enough off to be a problem.

So, if you are using negative photo resist, how do you produce your artwork? Ideally there is a little app that can print a gerber as a negative.

Phil

2

Well, after poking around and trying about 15 different utils, I found that gerbmagic has this capability. http://www.bronzware.com/GerbMagic/Download.htm

select polarity negative.

Once I get a little more experience with negative dry film resist (which means I don’t have to use pre-sensitized boards), I’ll report back here.

Phil

3

It took me a while to figure this out the first time I tried it. Instead of printing through the regular print menu, I generate postscript files using the CAM processor and then print those. Select the PS driver for positive photoresist or negative soldermask layers, and PS_INVERTED for your negative photoresist.

4

without a postscript printer, I’m not sure that helps much but thanks anyway.

5

You don’t actually need a PS printer, just print to a file with a PS driver.

Leon

6

leon_heller:
You don’t actually need a PS printer, just print to a file with a PS driver.

Yeah, I actually print with an inkjet, but my computer converts the postscript file automatically so I don't have to think about it. If you have to go through another conversion step, I guess you're no better off than having to load it up in gerbmagic.
7

Philba:
Well, after poking around and trying about 15 different utils, I found that gerbmagic has this capability. http://www.bronzware.com/GerbMagic/Download.htm

select polarity negative.

Once I get a little more experience with negative dry film resist (which means I don’t have to use pre-sensitized boards), I’ll report back here.

Phil

Philba, I have been searching for a technique like this. today "DirtyLude" a member from [www.electro-tech-online.com](http://www.electro-tech-online.com) guided me to this link. Can you please post your later experiences on negative printing please?

for example, Sprint has facility to invert the artwork.

while we are using either Eagle or PCB123.

thanks in advance

8

i feel i have got a easy way out Philba !

recently made a pcb123 artwork for a frequency counter. Leave it that PCB123 might have a facility for inversion. i saved the pdf of the artwork.

now i open the pdf

set it to 100& copy the image area alone by selection, paste in MS paint. make a second paste, below that. Now, in paint, select one image area and seek inversion. when completed, just offer print order and save as pdf.

the size appeared OK when printed on laser and measured, as compared to original Hope zit serves our purpose.

the original pdf and the invert pdf are both zipped and attached for comments

await feed back please.

PS:A print at 104 % is giving prefect size of the invert image and now i am confident that it can be managed.

Any comments from experts please !!