LISTSERV - TECHNET Archives - LISTSERV.IPC.ORG

TECHNET Archives

November 1998

TechNet@IPC.ORG

	LISTSERV Archives
	TECHNET Home
	TECHNET November 1998

	Log In
	Register

	Subscribe or Unsubscribe

	Search Archives

Options:	Use Monospaced Font Show Text Part by Default Show All Mail Headers
Message:	[<< First] [< Prev] [Next >] [Last >>]
Topic:	[<< First] [< Prev] [Next >] [Last >>]
Author:	[<< First] [< Prev] [Next >] [Last >>]

Subject:	ReCard Edge Connectors
From:	[log in to unmask]
Reply To:	TechNet E-Mail Forum.
Date:	Thu, 12 Nov 1998 20:16:33 EST
Content-Type:	text/plain
Parts/Attachments:	text/plain (33 lines)

Steve Lustig:
If memory serves me correctly (and sometimes it doesn't) card edge connectors
were prohibited as a design feature (due to low reliability) beginning with
revision B of Mil-Std-275.  Some of the reliability problems were attributable
to moisture entrapment (and associate corrosion/oxidation), dissimilar metals
juxtaposition (when plating was abraded by vibration) inconsistent contact
pressure/continuity in certain environments and so-on.  By the time Revision D
of Mil-Std-275 came around there was general recognition of the reliability
problems associated with edge connectors and it was not even referenced by the
standard because the problem was so widely recognized (the standard also
eliminated the requirement that solder connections contain solder, for the
same reason).  I think that IPC-D-275 and IPC-2221/2222 (which supersede IPC-
D-275) carry the same logic forward (sort of like ANSI/J-STD-001B does not
require that a solder connection be soldered - such things are supposed to be
intuitively obvious to even the most casual observer).  If you have a DOD or
other Hi-Rel customer that is contemplating the use of card edge connectors I
would suggest you discuss with him the design rationale that accepts/advocates
their use and carefully assess the field environment in which they are
expected  to operate (also try to get a contract to supply spares ;-).
Regards, Jim Moffitt, Moffitt Enterprises Consulting

################################################################
TechNet E-Mail Forum provided as a free service by IPC using LISTSERV 1.8c
################################################################
To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body:
To subscribe:   SUBSCRIBE TechNet <your full name>
To unsubscribe:   SIGNOFF TechNet 
################################################################
Please visit IPC's web site (http://www.ipc.org) "On-Line Services" section for additional information.
For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312
################################################################

ATOM RSS1 RSS2

LISTSERV.IPC.ORG