"Joe" wrote in message
ink.net...
Thanks all for the suggestions, I have a dremel, and this might be a good
project for me to learn how to use smt stuff. I will need to get a small
lighted magnifier tho, cause my eyes ain't what they used to be, even with
my reading glasses.

Joe

Joe,
If you are like me, you will want to use 805 or larger SM. 402 type drive me
batty, and if you ever drop one on the floor, it is gone forever.

Tam/WB2TT

"Tam/WB2TT" wrote in message
...

"Joe" wrote in message
ink.net...
Thanks all for the suggestions, I have a dremel, and this might be a
good
project for me to learn how to use smt stuff. I will need to get a small
lighted magnifier tho, cause my eyes ain't what they used to be, even
with
my reading glasses.

Joe

Joe,
If you are like me, you will want to use 805 or larger SM. 402 type drive
me
batty, and if you ever drop one on the floor, it is gone forever.

Tam/WB2TT



Hi Tam,

Actually, the ones that looked easiest to use were the 1210 case size. I
ordered some from mouser yesterday. I hope they're big enough for me to see.

I was wondering about a post I read somewhere else a long time ago. Is there
such a thing as a paste (that comes in a tube) that can be applied to the
terminals of a surface mount device and then when it is stuck to the board,
the paste hardens into something like hardened solder? So it is mounted to
the board and soldered with this paste?

Joe
KB1KVI

Joe wrote:
. . .
I was wondering about a post I read somewhere else a long time ago. Is there
such a thing as a paste (that comes in a tube) that can be applied to the
terminals of a surface mount device and then when it is stuck to the board,
the paste hardens into something like hardened solder? So it is mounted to
the board and soldered with this paste?

One-part conductive epoxy fits that description. It's commonly used to
mount SMT parts on hybrid circuits. However, the ones I'm familiar with
require curing at an elevated temperature (e.g., 150C for an hour). I
believe there are also some UV curing conductive epoxies. Conductive
epoxy can be used for mounting parts on a PCB, too, but I don't think
it's commonly done because it's considerably more expensive than solder.
There might be two-part conductive epoxies that cure at room
temperature, but I've never used one and am not sure they exist. The
one-part epoxies I've used aren't conductive until they're cured -- the
tiny conductive (gold or silver) particles in the paste don't contact
each other until the curing process causes the epoxy to shrink and pull
them together.

Then there's solder paste, nearly universally used for mounting parts on
PCBs. This also fits your description and can by applied by hand with a
syringe, then melted by a number of means -- hot air, IR, soldering
iron. It's actually a slurry of flux and tiny spheres of solder. It's
not really sticky, but sort of gummy, so some other means (like
superglue) has to be used if the parts need to be kept in place when the
board is inverted or severely disturbed before the paste is melted.

Roy Lewallen, W7EL

"Roy Lewallen" wrote in message
...
Joe wrote:
. . .
I was wondering about a post I read somewhere else a long time ago. Is
there
such a thing as a paste (that comes in a tube) that can be applied to
the
terminals of a surface mount device and then when it is stuck to the
board,
the paste hardens into something like hardened solder? So it is mounted
to
the board and soldered with this paste?

One-part conductive epoxy fits that description. It's commonly used to
mount SMT parts on hybrid circuits. However, the ones I'm familiar with
require curing at an elevated temperature (e.g., 150C for an hour). I
believe there are also some UV curing conductive epoxies. Conductive
epoxy can be used for mounting parts on a PCB, too, but I don't think
it's commonly done because it's considerably more expensive than solder.
There might be two-part conductive epoxies that cure at room
temperature, but I've never used one and am not sure they exist. The
one-part epoxies I've used aren't conductive until they're cured -- the
tiny conductive (gold or silver) particles in the paste don't contact
each other until the curing process causes the epoxy to shrink and pull
them together.

Then there's solder paste, nearly universally used for mounting parts on
PCBs. This also fits your description and can by applied by hand with a
syringe, then melted by a number of means -- hot air, IR, soldering
iron. It's actually a slurry of flux and tiny spheres of solder. It's
not really sticky, but sort of gummy, so some other means (like
superglue) has to be used if the parts need to be kept in place when the
board is inverted or severely disturbed before the paste is melted.

Roy Lewallen, W7EL


Thanks Roy,

It sounds like the solder paste is what I heard about. Sounds easier than
trying to solder such small parts with an iron. I will see if mouser carries
it and give it a try.

Joe
KB1KVI