[SOLVED] Copper clad board and etch resist ink opinions wanted

[d123]

Hi.

I was reading about ways to print your own PCBs, and read a few forum entries here as well, and - besides sending off to have it printed/made for you - the simplest seems to be using copper clad board and etch resist ink pens. The tracks in the photos I came across on other webs seemed quite wide, ...and "a bit cludgy" would be the description.

I can see advantages like not having to spend even more time at the computer making a design to send off for quite simple little circuits; it looks quite quick to do; and that you can get a good ground plane out of the unused copper areas; you don't have to spend a lot of money on a UV tank or time and money on modding an old scanner.
Disadvantages are that you don't learn how to do PCB design how it is done in 2015 rather than how it was done in 1931; the time it would take to drill any holes necessary for through-hole parts if used, and needing to get a drill support to make the holes without breaking several drill bits by hand; breathing in the noxious PCB dust or worse the etchant fumes; making a mess of a floor or furniture with a spillage; it sounds like narrow tracks can get etched away with unwanted copper during the etching process.

a) Is this suitable for making the tracks for SOIC or even QFP type components?/How fine can you draw the tracks using fine line permanent ink pens like "Staedtler permanent lumocolor", for example?

b) How many uses can you generally get out of the Copper whatever it's called etchant stuff?

c) How much of a regrettable outlay might I find this long-term if money doesn't grow on trees?

What experiences do people have of this method?

Thanks

 

[tggzzz]

I was reading about ways to print your own PCBs, and read a few forum entries here as well, and - besides sending off to have it printed/made for you - the simplest seems to be using copper clad board and etch resist ink pens. The tracks in the photos I came across on other webs seemed quite wide, ...and "a bit cludgy" would be the description.

Pens have sucked since the 70s and are no better now. Nonetheless they are suitable for some purposes. If you are curious about what's inside a 40 year old hack, (including techniques you don't want to try!) have a look at https://entertaininghacks.wordpress.com/tag/vintage/

I can see advantages like not having to spend even more time at the computer making a design to send off for quite simple little circuits; it looks quite quick to do; and that you can get a good ground plane out of the unused copper areas; you don't have to spend a lot of money on a UV tank or time and money on modding an old scanner.

A half-way house is the laser toner technique, which is good enough for double-sided boards with 0.1" DIP components - and maybe a bit more if you get the technique right.

Disadvantages are that you don't learn how to do PCB design how it is done in 2015 rather than how it was done in 1931; the time it would take to drill any holes necessary for through-hole parts if used, and needing to get a drill support to make the holes without breaking several drill bits by hand; breathing in the noxious PCB dust or worse the etchant fumes; making a mess of a floor or furniture with a spillage; it sounds like narrow tracks can get etched away with unwanted copper during the etching process.

Most of those disadvantages are avoided with a little care, household equipment and doing it outdoors. In other words, don't worry about it for the occasional board.

b) How many uses can you generally get out of the Copper whatever it's called etchant stuff?

One for ferric chloride. Of course if you put a board in 10 times too much etchant then you could still use it to do another 9!

c) How much of a regrettable outlay might I find this long-term if money doesn't grow on trees?

What experiences do people have of this method?

Thanks

For cheapness and fast turnaround...
Use laser toner transfer technique in preference to pens, unless there is a good reason.
Use ferric chloride in a plastic kitchen container, but don't put food in it thereafter!
Use latex/plastic gloves now they are easily available - they weren't in the 70s!
Do it outside if you are worried about fumes/dust etc.

If you want thin tracks or solder resist or fine pitch components, spend $15 and wait 3 weeks for a board from China.

My experiences are at https://entertaininghacks.wordpress.com/category/homebrew-pcbs/

 

[d123]

Thanks for the input and tips, and the links, I'll have a read this evening. Inbetween PDIP and starting to use more SMD components and not sure the best way forward re boards, so thanks, I'll look into the laser toner method a bit more in depth from what you say.

Nice tracks in the pictures lower down in "A 40 Year Old Hack, Disinterred"

 

[tggzzz]

Nice tracks in the pictures lower down in "A 40 Year Old Hack, Disinterred"

I've recently seen people put paint on a board and then mill/scratch away paint. There's nothing new under the sun!

 

[d123]

Hi! Necessity is the mother of invention! Do you mean conductive paint on a bare board, or another type of paint to cover the copper, like those pictures you do as a kid covering the colours with black poster paint and scraping bits off to make the image (the fondly remembered fireworks and bonfire night pictures primary school art class classic!)?
I'd wondered just how bad and time-consuming it is to somehow remove the unwanted copper by hand without etching, but think it's obviously not to be done except as an experiment out of curiosity when time is not an object.
There are helpful links on your blog/web, and the articles are interesting, thanks. I didn't know that ceramic SMD caps need warming first - important to know before the event!


Unrelated but related: Chip Art is fun to see; and this web has a lot of old circuits, quite beautiful to see, I really enjoyed the walk through history, it's in Italian but you don't need to understand it and some is easy to figure out from the words anyway:

http://ummr.altervista.org/before_microprocessors.htm

 

[tggzzz]

Hi! Necessity is the mother of invention! Do you mean conductive paint on a bare board, or another type of paint to cover the copper, like those pictures you do as a kid covering the colours with black poster paint and scraping bits off to make the image (the fondly remembered fireworks and bonfire night pictures primary school art class classic!)?

Oh hell, I do remember that art board.

Any paint that acts as an etch resist. I've used Fablon and nail varnish in the past, and wouldn't recommend either.

There are conductive paints but they are expensive and are probably useful if you want to repair tracks (?e.g. car window demisters?), or have an "arty" type thing such as a flexible board/fabric, or something quick'n'dirty, or for instant gratification with young children.

I'd wondered just how bad and time-consuming it is to somehow remove the unwanted copper by hand without etching, but think it's obviously not to be done except as an experiment out of curiosity when time is not an object.

If you can use a hacksaw, or have a sufficiently steady hand to use a dremel as router, then it can be done. I've used the latter for tiny RF attenuators: 2 SMD components, 2 connectors, 1cm*1cm.

I'm planning on using conductive copper tape for RF experiments, since can be quickly cut to shape and trimmed.

There are helpful links on your blog/web, and the articles are interesting, thanks. I didn't know that ceramic SMD caps need warming first - important to know before the event!

It is easy to get too hung up on possible problems that are principally relevant to high-throughput situations. Having said that, plastic packages (e.g. SMD LEDs) can be a problem since they are very hygroscopic - they visible *****.

Unrelated but related: Chip Art is fun to see; and this web has a lot of old circuits, quite beautiful to see, I really enjoyed the walk through history, it's in Italian but you don't need to understand it and some is easy to figure out from the words anyway:
http://ummr.altervista.org/before_microprocessors.htm

Thanks for reminding me of that. I have some very pretty pictures of thick-film hybrids from a 1970s advertising calendar. I must scan them sometime.

 

[tggzzz]

I have some very pretty pictures of thick-film hybrids from a 1970s advertising calendar. I must scan them sometime.

I have scanned them, and they can be seen at https://entertaininghacks.wordpress...of-late-70s-burr-brown-thick-film-hybrid-ics/

 

[d123]

Hi there!

Copper tape looks nice. I've decided that when I finish what I'm doing at present I'm going to experiment with a small copper clad board after seeing interesting ideas you link to. The hacksaw or painstaking gouging sounds about right, the drill sounds like "Oops, I slipped and cut a nasty groove right across that track there".
Thanks for the advice. Those photos of thick film Hybrid ICs are nice indeed.