Just realized I kept calling Jeff, Bert. Sorry Jeff!
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bkw
On 2/26/21 4:37 PM, Brian White wrote:
At least some are rectangular. I think they're still a bit thick but
maybe thin enough not to abuse the socket too bad.
With the leadframes, there are 2 potentially fiddly/random that can be
made nice and repeatable and practical by just procedure or technique.
I start with the leadframes by cutting the "busy" end off with scissors,
leaving a simple comb.
I hold the busy side in my left hand while cutting with my right, so I
can see both the shoulders where the pins widen and the scissor blade at
the same time. I just keep the scissors aimed about 2 mm away from the
shoulders as I go. The end result is good enough. The pins only need to
be roughly the same length. A little freehand wandering along the right
line doesn't hurt.
Or if you want you can make up some kind of jig like just cut a slot in
a piece of wood, drop the frame in, score the pins with a knife or flush
cut or draw a line with a fine tip sharpie. That would still be pretty
simple but I don't think even that much is necessary.
Either way, now you have a simple "comb" and it didn't take all day.
The next fiddly part is setting the depth of how far to put the comb
into the pcb to get legs that aren't too long or too short or slanted at
an angle, without having to trim them after soldering.
Probably the simplest way is just use a socket or a breadboard under the
pcb and just push the pins in untill they stop. Doing this, you have to
be careful the solder doesn't run down the leg and solder itself to the
socket. The tin leadframe legs reeeely love solder and it wets right
down the whole length easily.
Another way might be to stick a couple of objects like toothpicks or
something in between leadframe pins on top of the pcb, which stops the
frame from going all the way down.
Solder. Then flush-cut away the top frame.
Done.
There's a few things I like about Bert's idea.
The pins are already cut perfectly neatly on the free end.
And the pins are just normal gold plated and the solder won't instantly
wet itself down the whole pin. It will pretty much just stay where you
put it. That means there's no problem using a socket as a jig to set the
depth and hold the pins while soldering.
I also like that the end result is a gold plated pin instead of tin.
But I don't like the thickness of the pins, but maybe I need to take
another look, maybe it's no worse than machined round pins.
The more I think about it, the more I like Bert's idea.
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bkw
On Fri, Feb 26, 2021, 1:45 PM Stephen Adolph <[email protected]
<mailto:[email protected]>> wrote:
thanks for the suggestion Jeff. Those look like square pins right?
I don't think those will engage nicely with the typical DIL socket
you would see used with an IC though.
Am I wrong? Ive tried to stuff those pins into sockets before
and... it doesn't seem right to do that.
Steve
On Fri, Feb 26, 2021 at 1:37 PM Jeffrey Birt <[email protected]
<mailto:[email protected]>> wrote:
For the MOS8701/HB I produce I use the long tail stackable
headers commonly used for Arduinos. You want the type that has a
rectangular but not square profile with the thin side less than
0.5mm. These work well in normal leaf sockets and seem to work
well in machine pin sockets as well.____
__ __
The trick is you need a fixture to solder them. For example, if
you set your PCB down on a breadboard and push the headers
through you can top solder and trim the excess away. The plastic
part of the header is only serving as a carrier to hold the pins
in place in this case.
Jeff Birt____
__ __
__ __
*From:* M100 <[email protected]
<mailto:[email protected]>> *On Behalf Of *B4 Me100
*Sent:* Friday, February 26, 2021 10:27 AM
*To:* [email protected] <mailto:[email protected]>
*Subject:* Re: [M100] low profile pcb pins____
__ __
I have used the following two strips with the M100 SysBus socket
for quite a few projects - not sure it is the same format as the
NEC socket. The strips are very low profile which means the
modules easily clear the cover, even with tall components on the
top side. But they are expensive which is OK for one or two
modules but perhaps not for mass production. ____
__ __
Samtec TS-120-T-A 20 pins = $2.83____
https://www.digikey.com/en/products/detail/TS-120-T-A/SAM1112-20-ND/1105474?itemSeq=356013488
<https://www.digikey.com/en/products/detail/TS-120-T-A/SAM1112-20-ND/1105474?itemSeq=356013488>____
__ __
Mill-Max Manufacturing Corp. 335-40-120-00-160000 20pins = $6.83____
https://www.digikey.com/en/products/detail/335-40-120-00-160000/ED5932-20-ND/4455921?itemSeq=356013724
<https://www.digikey.com/en/products/detail/335-40-120-00-160000/ED5932-20-ND/4455921?itemSeq=356013724>____
__ __
__ __
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bkw
