Surface mount soldering

[gstopp at fibermux.com]

     I agree - surface mount stuff is within the realm of mortal techs to 
     install and repair. I work with prototypes and so lifted pins and 
     wires are common - but if the package has any pin spacing below 0.050, 
     send it downstairs to the little Korean ladies!
     
     For DIYers it just gets to the point where you really start to feel 
     the tradeoff between saving costs and doing it yourself, and paying 
     money to have it done for you. I guess the home-brew skills of the 
     past, like using solder lug strips and octal tube sockets, have 
     evolved through DIP packages and vectorboards, and now the skill is in 
     finding a suitable CAD package and local PCB house!
     
     On the plus side, PCB costs should drop a little as the hole counts on 
     the boards drop.
     
     - Gene
     gstopp at fibermux.com


______________________________ Reply Separator _________________________________
Subject: Surface mount soldering
Author:  KLEIN_B at A1.WDC.COM at ccrelayout
Date:    7/12/96 8:48 AM


You don't need the paste or anything special.  I work on disk drives 
all the time at WD.  All of it is surface mount.  Everything is just 
smaller, that's all.  Regular soldering techniques work if you are 
capable and can see the stuff.  There is a flux solution available 
that makes the solder flow better across multiple pin devices but 
you have to clean it off afterwards with a flux cleaner.  Realize 
that there are several sizes/types of components for surface mount. 
The first stuff we used was pretty cool for homebrew construction.
Pin spacings were close to .1 inch, the resistors and caps were .1 inch 
or so terminal to terminal, etc.  But now with the 100+ pin devices
and 1/8watt and smaller resistors etc. the stuff is too damn small. 
I have to wear those head-mount magnifiers all the time.  My eyes 
get worse year by year.  But we have rework girls that can work on
this stuff without them! (but they are making more and more mistakes!) 
So, it depends on the sizes of SMT stuff you work with.  I expect
that in a few years we will be paying a premium for through-hole parts, 
there will be so much more volume in the smaller SMT stuff.
     
What's funny is that from what I've seen, single transistors and fets 
are still quite usable in SMT form.  Nice size to work with.  So maybe 
us homebrew types will have to go back to fully discrete designs (!) 
just kidding....
     
     
klein_b at a1.wdc.com