Making pcbs

As far as I know there is no convenient or free legal way of disposing of the waste products from etching copper from boards. In my youth (alas distant, early 1970s) I poured it down the drain but I understand that this is frowned upon now.

Having said that, there are two methods which I have used, etching with Ferric Chloride solution and etching with a mixture of hydrochloric acid and hydrogen peroxide. Ferric Chloride needs to be agitated and works best if hot, hydrochloric acid and peroxide is quicker (and gets hot itself if too concentrated)  and cleaner. If you use photo resist you'll need sodium hydroxide solution to develop the resist, and some way of making photmasks. (Or you can paint the tracks on with paint or nail varnish (nail varnish is easy to remove)).

There are now so many cheap sources of custom boards that I wouldn't bother to make my own - use stripboard or dead bug technique for quick lashups and bought in boards otherwise. PCBTrain and the like are perhaps too pricey for hobby stuff but there are several much cheaper sources if you don't mind waiting longer.

MK

I have a set-up in my garage. Agitated ferric-chloride bath, tin plating, wet saw, ventilated drill press, xytable.  I have a thermal press that directly transfers stencils from a laser-printer. Haven't used any of it in years.  Another technique is to buy generic PCBs and modify them.  The 'op-amp evaluation boards' from the few remaining linear players are better than I can make.  Ebay ones from China for that sell for pocket change are as good as I make them.

Silicon connections are more reliable than PCB ones.  If it is digital and at all complex, I use a PROM if my I/O is balanced, otherwise programmable logic.  MCU evaluation boards have come along and are cheap.

Short of it is that I agree with you and am only trying to re-enforce you, Michael, in this.  PCB milling plus hole collars is the way to go nowadays if one insists.  Fun thing to do/have done, though.  Zoning won't allow any solns with Cu in them down the drain, so it doesn't matter.  SMT tech has apaced the small player.

Simulate.

Don Hersey wrote:

 

Another technique is to buy generic PCBs and modify them.  The 'op-amp evaluation boards' from the few remaining linear players are better than I can make.  Ebay ones from China for that sell for pocket change are as good as I make them.

SchmartBoard and Adafruit (links included) have some very nice SMT adapter boards.  A few of those and some 0.1" grid perf board can make nice prototypes.  I still use wire-wrap on occasion.

I do as well.  Nowadays, I need magnifying glasses late at night, to look at it from the outside, it is really tedious, doing it can be a great flow experience.  My first W/W tools were of poor quality, which made things really frustrating.  When I got a coupla good WWguns and a nice stripper things got much nicer.  There seems to be some movement toward pins that have a metric basis.  Does anyone have experience with these?  Also, there seems to be a 2x scaled W/W scheme used on stereos from the seventies.  Any insights as to where these tools might be available?

I have drawers full of surf boards.  If you are willing to wait for postage from the far sides of the globe, they can be very cheap.  So cheap that I inventory them rather than worry about the arrival of the mailman.

Thanks for the advice everyone.

As far as getting rid of the Cu, I can get rid of it when I need to through a local metals dealer who does some plating and my small amount of chemicals won't make a dent in theirs. So that doesn't worry me.

I attempted etching 35 years ago but did a poor job of it and resorted to paying for having prototype boards made for me. An expensive path to take in my town.

Does anyone do toner for smd boards?  Is there a high reliability way of doing this?

I have seen milled boards around the "local" hackerspace and they looked good but I can't get there anymore though due to an illness. How much money has to be forked out for a mill suitable for smd?

Haven't done anything previously with photo resist but have watched a few youtube videos. I seem to remember a video or tutorial on using a film based resist system but of course, I cannot find it anymore. If anyone knows of it and has a url can they pass it along? I think the guy used a laminator.  I watched so many videos last year on toner methods and etching I lost track.

Any advice on other systems?

Thanks again to all who responded

I don't know why I spelled pcbs with a apostrophe ... my wife and I had a discussion on this just the other day about how bad spelling and grammar is getting and I just did it myself!!  I should have spelled it as pcbs .. just found a way to correct.

Regards

Terry

Thanks John, I actually have some of the adapter boards from Adafruit and they are great for development but I still need to design a pcb for testing before "production". I only plan 30 - 40 boards per run when I do them but I spent too much on revisions through the pcb manufacturers and my wife has said I have to find another way. I no longer have access to work facilities as I am retired.

Regards

Terry

Yes, I just recently found my W/W tools and "had a go" but my eyes aren't what they used to be either and I quietly put the tools back in their box for prosperity or perhaps my son who may take an interest.

Regards

Terry

I use blue laser print film with a laminate press for toner fusion.  If your design is two sided you need to make a couple registration holes.  I use CorelDraw for making my images as this gives me better control as it doesn't understand circuit boards.  This way for instance, I can drop footprints atop each other if I want to late-bind to the form-factor of the parts I want to use.  Scrub your board with fine steel wool.  Wear eye protection when etching.  I bought a commercial etch bath with an aerator for an agitator and a robust aquarium heater.  I use ferric chloride, I like that it isn't fast.  The stuff stains like crazy.  Sometimes, large ground planes craze with the blue film, so I back them up with a chisel-point sharpie and/or tape.

Be patient and experiment.  Sometimes you have to do range-of-parameter tests like in chemical photography.

I think the milling machines for circuit boards run about 5K.  They are up to doing multiple layers, nowadays.

Thanks Don,

Can you put a name and product number to the blue film?  I have seen an ad for a green film called Pulsar Green TRF Foil   I was thinking of trying it and a toner transfer paper they sell if someone thought it was good to try or is it not worth the trouble.  I am yet to find anyone.  We have seen a product sold at one of the Australian electronic stores but it is $35 for 5 sheets. It is called Press 'n' Peel and looks similar to the product in Fran Blanche's PCB video on youtube. It may go under a different name in the US, Europe or UK.  Any good and if so, can you get it cheaper?

5K is a bit out of my price range - at least this year at any rate.  The hackerspace I visited have a DIY mill.  Any one on this thread done this? Any luck?  A chemical free way would be nice.

Regards

Terry

I use press'n'peel blue.  If you buy it in bulk it is cheaper.  You can tweak by messing with the printer settings.

If you look on eBay or Futurlec, The Electronic Components and Semiconductor Superstore you can find really, really cheap PCB fab services, just sayin'.