What diameter PCB hole for wire wrap socket pin?

[microMANIAC]

I am designing a PCB for a piggyback board which will use a 40pin DIP wire wrap socket to pass through the board and connect to the parent IC socket. These pins were not dimensioned for PCB insertion and I suspect they need a bigger hole than would be used for a standard IC socket. I don't want to insert the press fit part of the pin like you would if you were actually wire wrapping, I just want the long thin part of the pin to go through the hole. Does anyone know what hole diameter I should use?

[Jay_Diddy_B]

microMANIAC,

The normal size for these pins is 0.025 x 0.025 inches. The diagonal distance is 1.41 x 0.025" = 0.0355 so they will fit loosely 0.040" (1mm) holes.

Regards,

Jay_Diddy_B


I

[tooki]

I am designing a PCB for a piggyback board which will use a 40pin DIP wire wrap socket to pass through the board and connect to the parent IC socket. These pins were not dimensioned for PCB insertion and I suspect they need a bigger hole than would be used for a standard IC socket. I don't want to insert the press fit part of the pin like you would if you were actually wire wrapping, I just want the long thin part of the pin to go through the hole. Does anyone know what hole diameter I should use?

Wire wrap pins are the same size (0.025" = 0.64mm, square of course, so as Jay_Diddy_B said, multiply by √2 to get the diagonal) as normal header pins, so you can use whatever size hole you normally like for header pins. 1mm is usually good.

However, am I understanding that you ultimately want to plug the wire wrap pins into an IC socket? That's a bad idea, bordering on "won't work at all". The pins are much, much too thick, and will damage a regular stamped IC socket, and won't fit into a machined IC socket at all.

[microMANIAC]

...That's a bad idea, bordering on "won't work at all"....

Got that taken care of... the wire wrap pins are inserted into a pair of 20-pin female dupont PCB sockets, which are in turn plugged into the IC socket. The WW to Dupont connection is super solid, and the dupont to IC socket one is snug. Maybe surprisingly, it works extremely well.

[tooki]

Oh ok, that’s a critical difference.

IMHO there is a dearth of good options for pins actually intended to insert into existing, ordinary DIP sockets. (It’s been discussed a few times before, but practically nothing is available nowadays.)