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. -- bkw On Fri, Feb 26, 2021, 1:45 PM Stephen Adolph <[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]> > 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]> *On Behalf Of *B4 Me100 >> *Sent:* Friday, February 26, 2021 10:27 AM >> *To:* [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 >> >> >> >> 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 >> >> >> >> >> >
