Project: How to make PCBs

Thread Starter

Wendy

Joined Mar 24, 2008
23,415
Yep. Some of the most expensive wax paper you'll ever buy. Betcha when the misses sees it you could have gotten it locally. I figure it has a 1500% mark up with all the fees. Base cost for a roll, $1.30, including tax.

BTW, it really is good for baking, so be prepared to fight for one roll, I figured the other would be for the misses.
 

Thread Starter

Wendy

Joined Mar 24, 2008
23,415
Side note, in spite of my precautions, my small bottle of acid did the same thing my FeCl did to anything metal sharing the box. After etching another board for a different project I replace the paper towels, made it really thick and tight, then put them into a 1 gallon bag. I'll let you know if this works, I hate replacing tools.
 

EB255GTX

Joined Apr 30, 2011
62
Apologies for resuscitating an old thread here, but Ive only just come across it and believe I have something useful to add :)

- Brother toner doesn't work (as mentioned by several posters already). It's some organic resin based toner not pulverized plastic like the other brands.

- I use magazine paper rather than wax paper - works the same, but you are using the clay emulsion layer in the magazine paper rather than the wax on the wax paper. No worries about damaging your printer, cheaper than even wax paper is, at least for me since I get some trashy advertising junk in my mailbox most weeks. The best magazine paper is the thin, cheap stuff that is also usually recycled paper (the recycled paper falls apart better during the water soaking stage)

- I bought a cheap laminator ($40NZD) brand new, and modified the temp sensing circuit with a single resistor to increase the temp. You want the lamination temp to be high enough to make the toner sticky, but not so high that it becomes liquid. Luckily there seems to be a good amount of margin in that plastic phase region. Now I only have to pass the board and toner print sandwich through 3 times not 10 and i get perfect transfers, and i suspect that i could even do it in one pass but i like the certainty of 3 passes just in case a section got missed - btw i pass the board through in different orientations each time.

- The silkscreen side holds up better if you spray it with clear lacquer

- I always tin my boards - the tinning solution is expensive but I worked out that if you use a zip lock bag you only need a teaspoon or less of tinning solution and you can do a fairly big (3" by 4") board. Silkscreen side toner doesn't seem affected by tinning solution.

- I soldermask my boards too - you can get cheap glass paint that works well. Mask the pads using the same toner transfer method.

- CHeap paint thinner gets the toner off when you make a whoopsie just as well as acetone and is a lot less expensive. Generic brand thinner that is usually mostly xylene works well.

HTH
 
Last edited:

kbyrne

Joined Dec 10, 2011
93
I need assistance please. I am useing expressPCB and have Gimp with a PDF creator in express. My problem is how do I download from ExpressPCB and upload into Gimp at 100% . Every time that I try the printed coppy from Gimp is either undersized or oversized. Can you walk me thru from start to finish with any simple schematic and board available please. Thankyou newbi to this endevor.
 

Thread Starter

Wendy

Joined Mar 24, 2008
23,415
This one is a hard question. There are several key menu point in Gimp that have to be set, and I've lost them several times. I just muddle through Gimp until I found them and corrected these settings. I'll see if I can find them again, and post them, but to a degree you are probably going to have to just go through every option and do the same thing. I remember their being two.

******************************

First, and this is important, be sure your PDF printout is 600 DPI. If this is not the case you are spitting in the wind. I use PDF Print Forge to make my intermediate PDF copy. I had to search out the 600DPI mode for it too.

*******************************

Within GIMP proper look for <Image>, then look for <Print Size> . Set this for 600 DPI on both axis. This is the 1st point.

There is another issue I kept running into, I would get a "print.exe" error. I am pretty sure this is because the image is too large to fit the printer, since all printers have margins. The other issue is I try to use my inkjet I believe it has a max resolution of 300 dpi. Basically the error is caused from a mismatch in sizes or resolutions. How to solve it is to radically crop the right side and bottom of the image to shrink the sizes.

I'm still looking for the second resolution setpoint. I really don't like Gimp much, it is overkill for what I need and way too complicated. Unfortunately it is the only tool that does the job that I've found. I would drop it in heartbeat for something that allowed basic image manipulation like MS Paint and printed 600 DPI.

Found the second set point,

Edit/Preferences/Default Image

Set for 600 DPI.

Hope this gets you there.


If anyone comes up with a better tool than GIMP let me know. If must be able to import PDF files, convert them to .gif files, mirror the images, and print them in 600 DPI. If it let me cut/paste image onto the working copy it could replace MS Paint, but at the moment MS Paint is so much easier to use that it is part of the process. Part of the problem is the multiple layers GIMP has, they just mess things up.
 
Last edited:

kbyrne

Joined Dec 10, 2011
93
Thanks for the correct way. Have you ever tried out for size Ghostscript. It is available to you at SourceForge. It was recomended.
 

kbyrne

Joined Dec 10, 2011
93
:cool:
I am able to produce a board allright from ExpressPCB but my problem is downloading it with a PDF writer and uploading it into Gimp at 100% size. Does anyone have the proper sequence for this. the end result is always too small or two large. I need assistance for 100% every time. thankyou.​
 

Thread Starter

Wendy

Joined Mar 24, 2008
23,415
:cool:
I am able to produce a board allright from ExpressPCB but my problem is downloading it with a PDF writer and uploading it into Gimp at 100% size. Does anyone have the proper sequence for this. the end result is always too small or two large. I need assistance for 100% every time. thankyou.​
I merged this post with the target thread. Please do not try to open discussions in the Completed Projects thread, it is only for Completed Projects, and creates work for moderators. Besides that, it will not work.

If you want to start a new discussion use either the Electronics Chat or Electronic Projects forums.

Thanks for the correct way. Have you ever tried out for size Ghostscript. It is available to you at SourceForge. It was recomended.
Are you kidding! I struggle to get it to work the way I want as is! I am not about to introduce changes if I don't have to. :D
 

Fenris

Joined Oct 21, 2007
288
Hi there

I use a Linux OS but the following may be useful.

I installed a 'virtual printer' which prints to disk as a .pdf. The images are spot on for size.

I have just tested this with a 100mm square in ExpressPCB. Printed it and opened the .pdf in gimp and the image is spot on 100mm square.

Alternatively -

There are times where I have drawn a PCB up in a 2D CAD package exported the image as a .png and opened this in gimp to use the fill function to fill the outlines to make the solid trace image.

In gimp, I'm sure you know this, you can change the measurement scale from pixels to mm, as an example, then use the guides to frame the PCB outline.

Now measure the length or width. If the image is on the large size divide the actual size by the measured in gimp size -

100mm actual size / 150mm measured in gimp size = 0.666r . As a percentage this is 66.6

I now crop the image to its PCB outline then use the 'scale image' option in gimp. Change the default scale to percent and enter 66.6, make sure the 2 entry boxes change together and apply.

Now measure using the guides again, I say use the guides because the measure start and end point snap to the intersection, to check it measures correctly.

Save as a .png, open Open Office and >Insert>Picture>From File and select your design. Right click the image From the menu >Picture and under type check the Size. If it measures a little longer or shorter tick 'Keep ratio' and you can adjust the offending size. All being well if the gimp did it's job you wont have to, then export as a .pdf with confidence.

Hopefully the above options, regardless of OS, will help you. I use them all the time and have had no problems when having the final pdf's printed at my local printers to use for the toner transfer method.

regards

Fenris
 

Thread Starter

Wendy

Joined Mar 24, 2008
23,415
Once I have the setups done I don't have any problems, it is the setups that are crazy making. I would still like some other tools.

I wouldn't mind a teaching site for Gimp. It is a good software package, I need to use so little of it though.
 

EB255GTX

Joined Apr 30, 2011
62
...import PDF files, convert them to .gif files, mirror the images, and print them in 600 DPI. If it let me cut/paste image onto the working copy...
I realize this doesn't help you directly Bill, but hopefully the info in general is of interest (hey you mention you might have to learn Eagle one day....)

The image manipulation part can be really easy if you use Eagle. I set up an output job to export the board to postscript files. I run one job, and get copper and silkscreen and soldermask layers in seperate .ps files, mirrored or not as appropriate for the layer and side of board, at full res, and at actual size. I also get a fit-to-page sized silkscreen layer for assembly reference, and a drill guide also at fit-to-page size so i can easily pick which size drills i need.

As for editing the files before printing - I've never had to do this, do you do this to panel boards? Or to edit pads etc becasue your layout program does somethign you don't like? I have never had a problem with the Eagle output so have never had to edit anything, and for panelling up boards there are functions in Eagle to do that. Keeping everything in the layout program also means if you do another version you can change things and reprint....if you have a .gif file for printing that was editied from what came out of the layout program, you'd have to edit the layout then reapply your pad changes or whatever you did in the image editor every time surely?
 

Thread Starter

Wendy

Joined Mar 24, 2008
23,415
Not really, before I used Express I use MS Paint, and made PCBs that way.

The only reason I use Express is the netlist check.

I've mentioned it before, but after I am done with Express I change it up to make the pads something I like. One a recent thread I did before and after pictures. The changes were done with Paint.







 

Thread Starter

Wendy

Joined Mar 24, 2008
23,415
Because it is not needed. There are a lot of myths around, this is one. I don't reuse etchant, the etchant is cheap. When I was a young duck I imprinted on the style of the time, and this is it.

I've mentioned it before, but the technique is still a work in progress. My boards tend to turn dark very fast, which makes me suspect there is residual etchant still there. Next batch I will add backing soda to the rinse to see if it helps.

I'm also planning to run some experiments on nonconformal coating using Krylon Acrylic Clear spray paint on these board, but I need to ruin a sample board first to see if it works.

I would like to see someone else do something similar to this thead with photo processes. I also would like to see some alternatives to a laminator with this process. The idea is to make it easy for people who want to DIY and give them options.
 

nerdegutta

Joined Dec 15, 2009
2,684
I would like to see someone else do something similar to this thead with photo processes. I also would like to see some alternatives to a laminator with this process. The idea is to make it easy for people who want to DIY and give them options.
With reference to this.
I'm transferring my graphic to the PCB with UV-LED light. This is one of my latest board.
I design the board in Eagle, print it twice on transparent sheets, and expose the PCB to UV. After the UV exposure, I develop the board in 3 tablespoons of Sodium hydroxide (NaOH), for a few seconds, and then I etch it in either Ferric Chloride or in Sodium Persulfate \(Na_{2}S_{2}O_{8}\)
 
Last edited:

shortbus

Joined Sep 30, 2009
10,045
I also would like to see some alternatives to a laminator with this process. The idea is to make it easy for people who want to DIY and give them options.
Bill, instead of the laminator, why not a electric skillet or griddle and a brayer? The skillet/griddle is temperature controlled and the brayer would supply the pressure to transfer the print/toner.

A brayer is made for doing this. A flat piece of aluminum may need to be put into the skillet/griddle depending on how flat the skillet is.

A brayer link - http://www.amazon.com/Ranger-Roller-Brayer-Medium-16-Inch/dp/B000S13H42/ref=pd_bxgy_hg_text_b But they are available from about any craft store. And electric skillet could come from second hand store or yard sale.
 

Thread Starter

Wendy

Joined Mar 24, 2008
23,415
I have tried something like that, with poor results. One of the other guys mentioned he used a rolling pin and got it to work, but not with much detail.

If I can get my hands on two flat smooth pieces of aluminum I'll try a baking process.

The main thing is reliability.
 
Last edited:

EB255GTX

Joined Apr 30, 2011
62
The main thing is reliability.
That's why i love my laminator! Consistent transfers every time. I should mention another trick i use is to buy 0.8mm board (half the usual thickness) as it is easier to cut and work with heavy duty shears, and for double sided i just make 2 seperate boards and epoxy them together.
 
Top