>

> Need some help determining if we can remove a press fit connector from

> a PCB and replace it with a new press fit connector? PCB plating is ENIG.

> This is a Class 3 assembly. I can't seem to find it in any IPC document.

> Thanks in advance.

>

> Regards,

> Steve Vargas





Steve,
I'm not sure it's addressed in any IPC pubs.

IMHO (IMAO?) The benchmark standard for pwb's and pressfit is the Bellcore, errr...  Telcordia,  errrr...  GR-78-CORE.







It's about determining via integrity and gas tight joint are good as part of a qual and after reinsertion are still good.  Need to cut up some pwb to really know for sure. At a minimum need to do some pull tests and see that the delta in resistance value before and after are low enough and minimum retention force is high enough to indicate a gas tight joint.


a)      gas tight joint between pin as demonstrated by a minimum force required to remove a pin and resistance

and

b)      the via integrity by maximum deformation, minimum plating remaining and no interconnect cracking or seperations in the pwb





"Section 4-2:

R4-9 ...  The minimum force required to remove a single pin or contact shall not be less than 7.5 pounds....  The requirements on the resistance and on the change in the resistance in press-fit contact (such values are expected to be less than 1 milliohm) apply after initial insertion, after replacement of pins, and after environmental stressing to simulate end-of-life conditions;..."



R4-10

...the average plated-through hole deformation radius shall be no greater than 0.0015 inch when measured from the drilled hole. The absolute deformation radius shall be 0.002 inch...



R4-11

...the minimum average copper thickness in the plated-through hole remaining between the pin and the laminate, averaged over a 10-hole microsection sample, shall be no less than 0.0003 inch. In addition, there shall be no copper cracks or other interplane separation from the plated-through hole barrel or separations between the PWB laminate and the barrel."



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