Making Perfect PCB's At Home.

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Good info , Mooly.
For the printouts, Mega also sells a sort of matte foil for laser printers called Laser Star, which work great with laser printers, A bit costly, though....
Stacked prints on ordinary laser print foil also works for not-too-thin traces.

There ia a matte opaque film called F100tcc which is identical to Laser Star in look, feel and performance. I have both and cannot see a difference

F100TCC Transparency Film

and its only £17 for 100 sheets.

Rob
 
I usually get my transparencies from ebay!

I have also tried putting the tranparency through the printer for a second run, but the alignment is never good enough to allow for this. Maybe this is only a problem because most of my designs use 0.5-0.65 pitch SMD parts, so would require the two prints to line up better than within 0.1mm of one another. If I was only using DIP size parts I don't think it would be an issue.
 
I also use Mega for most of my supplies... I've been using their 3m solder resist film for a year now....and it really makes the boards look the bizz..and makes soldering easier.

This is a picture of the F100tcc film used to make the solder resist.

An externally hosted image should be here but it was not working when we last tested it.


and this was my first attempt at affixing the resist to a pcb and developing it.

An externally hosted image should be here but it was not working when we last tested it.


It came out quite well,but I hadnt baked it (the pcb) dry beforehand or scoured it slightly before the tin plating, doing both helps the resist film adhere properly .

Rob
 
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I also use Mega for most of my supplies... I've been using their 3m solder resist film for a year now....and it really makes the boards look the bizz..and makes soldering easier.

It came out quite well,but I hadnt baked it (the pcb) dry beforehand or scoured it slightly before the tin plating, doing both helps the resist film adhere properly .

Rob

That looks great Rob, fantastic job.
 
The problem I always have is getting the image BLACK enough. With either my laser or inkjet printers the image still allows sufficient light through to spoil the final result.

That's why I always feed them twice or three times through my El Cheapo Canon IP4500 InkJet and print the same image , that works great !

There is no need to double run through printers. Use best quality settings as Mooly has said. Probably you were using a light source with the wrong wavelength.

There has to be a way to do photo resist without buying board, All board houses do. Finding double sided 2 oz. board in the thickness that I want already done is my problem. But I will find a solution for sure.

Yes, board houses use dry film laminate applied by heat which is a positive resist, rather than the negative resists used by DIYers. I looked into this method as I was finding tiny defects in precoated board, but ended up buying a small CNC machine instead as it avoids messing with etching and chemicals.
 
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Getting enough contrast may be a function of the print media, in my experience. That's the beauty of the specialized film media.
Wrong wavelengt of light source will usually result in underexposure, which gives long developing times and/or bad coverage of the resist after developing.
We use a light box with 6 tubes pr side, and an exposure time of appx 2min20sec, a a distance of appx 5-6 cm. The fuzz with the light source and light wavelengths, is of course that the resist is designed to be most sensitive to this light, ans also be safe to work with in normal room light.
I just checked som old tubes that I stored as emergency spares - they are Philips TL-20/05 20W....
 
Nice write-out and very good results :)

I really like Bungard photoresist boards btw. Their resist holds up really well even in a strong developer bath. They're quite cheap at reichelt. With fine traces, I've found that the etching bath is more problematic than the developer's one: if it is too weak, the etching will take too long and the etchant will creep under the resist from the sides of the track.

And the cheap nail curers you can find on ebay (the 36w ones) or amazon work decently (correct wavelength), if you can't afford a proper uv box.
 
Cupric Chloride Etchant

If you do a lot of PC board etching you might want to try Etching with Air Regenerated Acid Cupric Chloride
This site explains how to make and use this method. The advantage is, after you have generated the acidified cupric cloride solution,you can use it forever,just regenerating it by bubbling air through it with an aquarium air pump. You will need to make an etching chamber to hold the etchant at about 104 degrees F, and agitate the solution with an air pump. Also, I get good results with a toner transfer method using Techniks press and peel (All Electronics part # Tek-5). Not cheap, but you just print the artwork and cover the artwork on the printed sheet with a small piece of press and peel and run it through the printer again. Just remember to mark the paper before the first printing so you use the same orientation in the printer, and set the printer for maximum toner density. A method for good transfer to the clean copper is explained in the user comments about press and peel in the All Electronics order site. This way you don't need sensitized board
 

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When I used to do my own boards I used an EBV or #2 photo flood lamp. Under $3 and a 500 watt incandescent. 5 minutes exposure time at a distance of 12 inches.

In those days I taped up the layouts and sent them out to get film negatives.

I used Kepro precoated boards that were developed with trichloroethylene. Too hazardous for today.

I still have my desktop spray etcher. Haven't used it in years.

I use Express PCB and save up projects until I fill a 12 x 14 inch panel. They allow you to also layout the trimmer path so I can get a fair number of cards on a panel.
 
I wonder if it would be possible to use this to print a thin layer of plastic onto the board then etch it in the normal manner.

Buy 3D Printers RepRapPro Ormerod Full 3D Printer Kit RepRapPro Ormerod 384 online from RS for next day delivery.

*Maybe*.
Essentially the same as iron-on transfer from a Laser print, where you also transfer a thin molten plastic layer to the copper surface.
I fear the 3D printer molten plastic may not stick too well to a cold shiny bright copper surface.
Of course, in its original application it sticks well to itself.
Sticking molten plastic to more of it which was still molten 5 seconds ago is *much* easier.
 
I'm onto a different thought now.

My Epson RX585 can print onto a CD using the supplied adaptor.

It's not difficult to adapt the adaptor to hold a piece of PCB material.

1. When I insert the CD tray the computer/printer automatically knows that I have inserted it, the PCB software will only print onto what it thinks is paper.

2. When the computer/printer is printing to a CD it automatically misses out the centre, great if you want a PCB with a hole in the centre.

Any ideas ?

Does that make sense? The PCB software wont print when I am using the adaptor because it thinks that I have inserted the incorrect media (ie a CD).

http://www.pabr.org/pcbprt/pcbprt.en.html has some very useful tips about printing directly onto the copper if only you can get the copper into the printer.
 
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