DIY PCB manufacture - through hole plating

There's no "easily" here. Even the best PCB houses, with resident chemists, screw it up from time to time.

If you want to make your own boards, poking wires into vias and soldering is probably best. But you can get plated-through 2-side boards cheap nowadays.

John

Whoops, I forgot to mention that I'm a hobbyst (sp?), as well as a poor uni student. :-)

I've seen many people make that same comment, and I guess I'd be inclined to agree, however I'm interested in doing this for myself for no real justifiable reason. I'm sure the excitement will wear off pretty quickly, but I'd like to be able to whip little things up now and then when I need it (and not have to fork out at least $50 to get simple PCBs made from places like custompcb.com -- the only place availble to me here in Brisbane, Australia, would cost a minimum of about $400 for a single board. (that's from

Anyway, assuming that I'm making these myself, does anyone have any ideas about the "Multicore Copperset" thing, or even the "bail bars"?

Thanks!

Two suggestions:

One: AFAIK plated-through holes are made by drilling either bare board or very lightly plated board, treating the holes with conductive epoxy, and plating on copper until the desired thickness is reached. Then you etch the rest of the board.

Two: See if you can get a job at that PC fab house! Assuming that your major is some technical discipline it'll look damn good on your resume, you'll learn _lots_ about fabbing boards, and who knows -- maybe you'll be able to sneak some of your boards into the process!

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

1) Hrm, is this similar to the chemical process used by professional manufacturers in the big expensive tanks? I looked into that, when researching the process (albeit, not too deeply) but decided that I'd stick to something more mechanical (ha, maybe chemicals just scare me :-D ). I don't mind having to spend a bit of time putting the little eyelets or pins or bars in holes and punching them, I just havn't been able to find a supplier for this "Copperset" stuff or the bail bars that a few websites seem to talk about. Then again, if everyone agrees that this chemical process is the way to go, I might look into a bit more (assuming it's relatively economical).

2) Ha, don't worry, I've tried. :-) I'm doing Computer Systems Engineering, so playing with PCBs and embedded devices is right up my alley -- but it's hard convincing them that a lowly uni student needs to work there. :-)

Regards, Michael

Rivets/eyelets are 1960's technology and have lots of problems of their own. The classic US vendor was USM, United Shoe Machinery Co.

Hey, this is cool:

John

These days it is very cheap to have PCBs made. It may cost a bit more and you have to wait longer, but especially double sided PCBs are well worth the extra money spend.

--
Reply to nico@nctdevpuntnl (punt=.)
Bedrijven en winkels vindt U op www.adresboekje.nl

Digikey can special order a Copperset kit for about $350. The bails cost $65/stick. You can order a whole lot of boards for that kind of cash.

-- Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack there of) at:

Shameless Commercial Division:

Not exactly the system you mention, but something that might be useful (I have not tried however): there exist metallization rivets, produced by CIF. They are a bit thick: for 0.8mm final hole a 1.3mm hole in the PCB is required, for 1.1mm - 1.6mm. A picture can be found here:

A rivet tool is required as well (on the picture). I am not sure if Selectronic would ship these items abroad. I think the same things are sold by Farnell (at least in Europe), order codes 4208742, 4208754,

4208766, but you'd need to validate it with Farnell as they don't provide details.

-- Andy

Farnell sell them, they have pretty-much world-wide distribution:

I've used dozens (maybe a hundred) of them, they work great. The method given on your link is fine, pretty much how I do it. The Pentel pencil is ideal. I've never had a failure. It makes soldering both sides of a component when only the bottom is available (under big capacitors or D-connectors for instance) easy.

If its just a via (connection from top-to-bottom with no component) use wire - it's cheaper.

Another way to do connections from top to bottom when only the bottom is available for soldering, is to solder a fine strand of wire through the hole, to the edges of the hole, before inserting the component and soldering it at the bottom. Occasionally the wire lifts on the top when the bottom is soldered again though.

Rick.

When i made my own 2-sided boards during the "good old" tape daze, i did my best to use DIP pins and part leads for as many of the top-to-bottom connections as possible. Aboout 10 percent (at most) of needed connections i did by the wire method (as suggesed).

The oly other altenate i can think of is to use copper or brass rivets, then solder them (both sides).

Don't go down the chemical route ! I was a PCB production manager for ten years and developed a lot of the multilayer techniques. The electroless process (depositing copper down holes) begins with a strong solution of fluoroboric acid which eats glass (and many other things !) This is where the alarm bells start ringing and you should start thinking about the other methods - don't do it ! Good luck Pete

Wow, did you see this?

Incredible.

--
Thanks,
Fred.

cost

cash.

Ouch! I was under the impression that they were a lot cheaper (the bails that is, if not the kit itself) - I was planning on getting a stack of bails and then figuring out some way of punching them in myself. Run over the tops with some solder paste and a hot air gun... voila! :-)

Ahhh, I can but dream. :-)

Michael

useful

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Hrm, that's looking promising -- I was originally planning on just getting a nice, specific purspose system (like the Copperset thing) but now it looks like I might have to run with rivets of some sort. Do you know if you have to solder them afterwards? (or do you have to do that with most of these punch-metal style systems?) My french (?) skills arn't that great - I speak aussie most of the time, maaaate. ;-)

Now, to only find them in smaller sizes....

Michael

Excellent! For some reason, I couldn't find them. I think I lack the search-engine-mastery gene. :-)

Actually, can I just clarify something - if you use a pacer (pencil) thing to put them in, do you still need the expensive kit? Or is that just an expensive applicator device?

And, similarly, my original link mentions a 'modified centre hole punch' - for the life of me, the image I have in my head for a centre hole punch wouldn't have a hope of doing anything useful to a PCB. how does that all work?

Yeah, that's what I'm planning on doing - the only problem is I'm planning on doing a lot of double-sided SMT stuff, and a lot of vias are under (very) flat ICs. In the past, I've found it a real bother to get the ICs to sit flat for soldering with bumps underneath them.

Does this method come out much 'flatter' that the ol' wire method?

Thanks for your help,

Michael

the

strong

!)

thinking

Hahaha, thanks for the heads up. :-)

Personally, I'm actually a little afraid of using chemicals for everything - it's bad enough using developer and then Ammonium Persulphate to etch PCBs. I think it's just a lack of exposure to chemicals, though - I'll get over it soon. :-)

Cheers!

Michael

Granted. But the newer technology is not always better in every aspect. That's why I guess Farnell stocks both. Depending on requirements, the rivets could be optimal.I could use them in occasional prototyping, in particular for the holes receiving the components. Even for the vias; soldering a wire as a via can be fun: when it desolders on the other side and either turns in every bad direction.

Yes, it is! A clever idea.

-- Andy

Well, even if it was not specified (the Selectronics's page is mute on the subject), I would advise so, to ensure the contact. And then, you can solder the components in the rivets. This would facilitate the later replacement of the component, compared to soldering the component directly to the copper on both sides of the board.

I am not sure which system you mean, but the Copperset thing does involve soldering.

Oh, good yakka at the uni then, cobber! :-)

This may be problematic. I have not seen such rivets in smaller sizes.

-- Andy