[sci.electronics] how to make 3+ layered boards?

pad@probitas.cs.utas.edu.au (Paul A Daniels) (06/11/91)

	Yet another title says it all posting.
Can anyone tell me how to do it. I would also like to find out about methods 
for mounting suface mount components.


			Thanks in advance,
					Paul.

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pad@probitas.cs.utas.edu.au
pad@tasman.cc.utas.edu.au
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--
Paul A Daniels
pad@probitas.cs.utas.edu.au               "If I knew what I was doing
+61 02 202904                                 I wouldn't be here"
Computer Science Dept Uni of Tasmania         

steve@nuchat.sccsi.com (Steve Nuchia) (06/11/91)

In article <pad.676610517@probitas> pad@probitas.cs.utas.edu.au (Paul A Daniels) writes:
> Subject: how to make 3+ layered boards?
>	Yet another title says it all posting.

A neat trick for home prototyping is to burn the artwork onto the bottom
sides of a bunch of boards and stack them one at a time onto wire-wrap
sockets.  That way you can make as many layers as you need and don't
need any plated holes.  Use bits of wire or something to make your vias
work.

For production you have to pay someone who knows how to do it.  Even if you
had all the materials, it would still be just about impossible without
the equipment.  Do the artwork on cad and give a floppy to the board
shop.  It's the only way to fly.

For small quantities, like less than 6, you might be happier doing
two or even one sided boards at home and using wire-wrap and/or
jumper wires to handle whatever you weren't able to route.

>Can anyone tell me how to do it. I would also like to find out about methods 
>for mounting suface mount components.

You can always use through-hole sockets for PLCCs.  Gull-wing type parts
can be soldered by hand if you are patient and have the right tip.

I've also heard that you can do reflow soldering in an ordinary
home oven.  Tin the leads and the pads, find some way to hold the
components still (maybe tack-solder some leads down?) and stick it
in a preheated oven (say, 450 F) for a few minutes.  Time and temp
will have to be calibrated, so having a bunch of junk parts and
borads to play with would help.
-- 
Steve Nuchia	      South Coast Computing Services      (713) 964-2462
	"Innocence is a splendid thing, only it has the misfortune
	 not to keep very well and to be easily misled."
	    --- Immanuel Kant,  Groundwork of the Metaphysic of Morals

henry@zoo.toronto.edu (Henry Spencer) (06/18/91)

In article <1991Jun11.125843.105@nuchat.sccsi.com> steve@nuchat.sccsi.com (Steve Nuchia) writes:
>> Subject: how to make 3+ layered boards?
>
>For production you have to pay someone who knows how to do it.  Even if you
>had all the materials, it would still be just about impossible without
>the equipment...

It *is* possible -- I know people who've done it -- but without a fair bit
of moderately costly equipment, you're not going to consistently get quality
boards out of it.  Dependably getting high-quality plated-through holes
requires precise control of things like solution chemistry and temperature,
plus a substantial debugging process to get the parameters set right.  This
essentially amounts to setting yourself up as a board production shop, at
considerable cost.  Adding copper is a lot harder than subtracting it; there
isn't any basement-bench way of doing it that reliably gives good results.
If you want something that will give you a good board the first time every
time, and don't want to spend a lot of money and effort on it, you need to
pay someone who *has* spent the money and effort.
-- 
"We're thinking about upgrading from    | Henry Spencer @ U of Toronto Zoology
SunOS 4.1.1 to SunOS 3.5."              |  henry@zoo.toronto.edu  utzoo!henry