CNC PCB isolation routing and DIY through holes

I’m looking at using my CNC machine to do some prototypes and one off boards using the isolation routing technique, yes, I’ve used the PCB deal a few times, and while very happy with the results, I’ve found that the turnaround times are a pain when living in Australia, especially for a project I just want to “whip up” on a weekend.

I have no problem with isolation routing, just the through hole side of things for 2 layer boards. So I’ve been investigating DIY through hole plating and found this product.

http://www.thinktink.com/stack/volumes/ … inksup.htm

Has anyone used it before? Comments?

Anything else that can be recommended for DIY though holes? (other than soldering small wire in the via)

Stephen…

That seems like a LOT of work for a weekend project. Some people use grommets but I can’t help think that it’s a big waste of time, too. What’s wrong with wires? I use that all the time and it works fine not to mention is quick.

When I lay out my board, I try to make the places where a signal passes from one side to the other occur where I can solder both sides. For example, if you have a TH resistor, both sides are accessible for soldering. You can use a number of components for this. It helps to minimize the number of vias you need. I call this approach non-plated through hole design rules - NPTH DRs. Of course, you have to hand route the board but that’s no hardship for me.

The track pins mentioned near the bottom of this page: http://electricstuff.co.uk/pcbs.html

are at least better/faster than bits of wire, but still have the inconvenience of leaving the hole plugged. On balance I prefer them over the hassle of DIY through-plating.

no first name supplied:
The track pins mentioned near the bottom of this page: http://electricstuff.co.uk/pcbs.html

are at least better/faster than bits of wire, but still have the inconvenience of leaving the hole plugged. On balance I prefer them over the hassle of DIY through-plating.

I am pretty happy with the speed of using wire - you strip a length of solid core wire and thread it through all the vias. Then solder both sides of each via and clip off the excess wire. quick and easy. not to mention cheap and oneless thing to stock up on. You can also use the excess wire to do a continuity test easily.

Thanks Guys for the replies,

makes sense about using wire, so I’ll look at trying that first.

Stephen…

What are recommended sizes for vias when using the wire method?

Thanks…

What are recommended sizes for vias when using the wire method?

Thanks…

I use 0.8mm holes for home-made wire (or track pin) vias. It really depends on what wire you’re going to use. You want the wire to be reasonably snug, but not hard to push through the hole.

The only drawback of doing vias like this is that it’s not practical to have vias under things like a TQFP, which can make it tough to route some traces.

true - in general, I think you should stay away from vias under chips on home made boards, no matter how you do them. It kind of ruins your day if the via needs resoldering.

By the way, there are other services that turn PCBs a lot faster that SFE though you will pay more.

I like http://www.barebonespcb.com/ if you need it fast but < $100, and 33each.com if you need solder mask etc but don’t mind waiting a week. Students can order just one PCB instead of 4.

Hey Stephen, let me know if you find any good places or ways of doing double sided boards. Sadly I don’t have a CNC but would happily pay a company or even another hobbyist to get some boards done.

I know what you mean about the wait to Australia, usually I budget one month, sometimes more. When you need to go through 4-5 board revisions it gets kind of slow.

Maybe someone should start up an Aussie batchpcb, even if it only ran a panel every fortnight it will still only make it a 1 week affair if you ordered right before the panel was sent off to the manufacturer.

Regarding barebonespcb and variants, in my opinion anything above $80 is too much.

For $80 I can get a full sized panel from GoldPhoenix with a turnaround of about a week and a whole stack of boards compared to just a couple.

For bigger projects that’s what I have done in the past, ordered a whole panel just for two or three 2"sq boards. Sure speeds things up.