Hi

I was wondering how to make a pad for the chip then thought use a
piece of PCB with a cut through the copper in the centre and then
additional cross cuts of the copper to make the lands for the holder.

By bending out the legs of the holder they can be soldered to the pad.

Chip Pad Photo added to my album.

Charles G4VSZ

开云体育

Hi Charles,
what you describe has been used in VK for a while now, described (and
used) by Drew Diamond VK3XU - he is a master of this style of
homebrewing and has published many articles over the years (and 2
books) - some construction articles are available in .PDF format from
the website
go to AR mag page and have a look around.
Well worth the effort for inspiration!
73 de VK3BFA Andrew

-- In BITX20@..., "Charles" <charles@d...> wrote:

Hi

I was wondering how to make a pad for the chip then thought use a
piece of PCB with a cut through the copper in the centre and then
additional cross cuts of the copper to make the lands for the

holder.

By bending out the legs of the holder they can be soldered to the

pad.

Chip Pad Photo added to my album.

Charles G4VSZ

I was wondering how to make a pad for the chip then thought
use a piece of PCB with a cut through the copper in the centre
and then additional cross cuts of the copper to make the lands
for the holder.

That's what I do too, when I need to. I use firm pressure on one of those
cheap orange plastic "craft" knives. You can produce a nice thin cut with
this method. The LM386 in the BITX20 I just mounted "ugly" though, with no
pads. I tend to use the knife method if I need to use surface mount IC's.

The pinnacle of the art came when I found I had to connect a 24-pin Analogue
to Digital converter chip, in a TSSOP package. Pin spacing was a mere
0.65mm. In other words, 4 times denser than your BITX20 LM386. To do this I
cut 2 columns of 6 pads on either side of the IC (24 pads total). I glued
the IC to the board. The even-numbered pins (2, 4, 6 etc) were bent upwards
away from the board. Odd-numbered pins (1, 3, 5 etc) were soldered direct
onto the pads. The even-numbered pins were then connected to the outer
columns of pads using the hair-thin individual strands of copper from
ordinary lighting cable. You can find a picture of the result about 2/3 down
on the left hand side of this page



People who work with SMD talk of special soldering irons & bits, special
solder, magnifying glass, flux, special lights etc etc. I used none of this.
Just my ordinary 18W Antex CS iron with 1mm bit and ordinary 22swg solder.
Just goes to show that the patient homebrewer can accomplish a lot even
without specialist equipment.

72/3 de Hans G0UPL

An easier method to make a pad for non-SMD IC's is to use 0.1"
Veroboard instead of plain copper laminate.
Then only one saw/knife cut is required.
KISS?

Duncan G4DFV

On Jun 29, 2004, at 3:31 AM, g4dfv2004 wrote:

An easier method to make a pad for non-SMD IC's is to use 0.1"
Veroboard instead of plain copper laminate.
Then only one saw/knife cut is required.
KISS?

And an even easier -- yet vastly more expensive -- method is to use one of the etched adapter boards that brings out the pins from a surface-mount chip to 0.1-in spacing pads. SMD chips can be soldered to these with little difficulty and a small iron as Hans noted. Nowadays I use a lighted magnifier -- even on DIP stuff -- because it's a lot easier on me.

And I have a cute little Intel Play USB microscope that has a 10X setting for the more challenging SMD stuff.

Jim N6OTQ