At home, I etch single and double sided PCBs but there are a few of areas I've always had trouble with. Can anyone help?
Tinning
The PCBs I make are useless for hot air rework or skillet reflowing. Once the copper heats up it oxidises, then I'm unable to solder anything else to the board.
Rubbing wet solder wick over the PCB helps, but I usually just end up damaging the tracks.
Will a tinning solution solve this?
Is there any other way?
Vias and plated through hole
So long as I keep vias big and away from components I can solder short pins or wires through the board. But, these vias are too raised to go under a chip, which is often where they're needed.
Is through hole plating possible/practical at home?
Are there other ways?
Cutting
I buy presensitised FR4. It's not cheap, so I like to cut up the sheets to avoid waste. Strong scissors can cut it, but they sometimes curl the edges which makes it hard to get a good contact with the transparency when exposing.
What's a cheap way to cut PCB?
Coating
There's no soldermask, so I have a lot of exposed copper. Is there something inexpensive I could use for a better finish than hotglue?
Thanks.
Best Answer
For tinning, my cheap home method is to coat the traces with a flux pen as soon as the board is finished etching, then run all over them with the thinnest coat of solder from my iron. I've drilled them before and after the flux and or tin process and usually prefer to drill before fluxing.
I too use tin snips for cutting my boards, sometimes sanding the edges with 600 grit wet and dry paper with water and a little soap to get a nice smooth edge.
Conformal coating is available to coat and protect your board. I'm planning to give polyurethane varnish a try on my next project.