>>>>> "Ed" == Ed Kelleher <Pres_at_macro-inc.com> writes:
Ed> At 11:52 AM 9/13/2004, you wrote:
Peter> Ignoring memory, I'm pretty sure could get 1000 transistors +
Peter> support parts/diodes on a 12x12" card. Doing the component
Peter> placement would be a pain however.
>> Why? A good light, magnifying glass or small stereo microscope,
>> fine tip soldering iron, fine solder, and flux -- plus patience.
>> No sweat.
Ed> Placement is still a pain, but the soldering part might have been
Ed> relieved some.
Placement: tweezers and tooth picks.
Ed> Since it's getting tougher and tougher to find through hole
Ed> components, next PCB design I do, I'm planning on doing as much
Ed> SMT as I can.
Ed> I'm going to investigate the toaster oven solder method also:
Ed>
http://www.pcbexpress.com/stencils/index.php
I saw that. It makes sense for BGA parts where you have no choice
(short of sending it to a pro). I wouldn't use it for anything else.
It's hard to believe that there is enough temperature control to keep
from frying stuff. And you have to place (and secure) all the pieces
without dislodging any. Far easier to place individual parts one by
one and solder them as you go.
I watched a professional technician assembling prototype boards that
way -- several hundred small passive parts, active components up to
240 lead flatpacks. I applied her approach on a somewhat smaller
scale -- perhaps 150 capacitors, a few dozen resistors and resistor
arrays, ASICs up to 120 leads. Again, no sweat.
paul
Received on Mon Sep 13 2004 - 11:19:04 BST