At 09:19 AM 9/10/2009, you wrote:
>Brian,
>Drilled hole size is no-doubt, far-and-away the #1 cause of c-pin 
>deformation problems.  Ideally the drill and maximum drill wear 
>should be defined.  In most cases you cannot allow the fabricator to 
>substitute imperial for metric.  Be careful not to get yourself in a 
>double toleranced contractual nightmare:  bigger hole with lots of 
>Cu generally works well, but if the fabricator is allowed to choose, 
>they will pick little hole with little Cu.

Amen. Preach it brother.

Ergo, we specify the actual drill bit -- not a nominal with a 
tolerance for the drill -- THE ACTUAL DRILL.    I'd put that in red 
for effect but I really DO have the t-shirt.

>Also be aware that the fabricator will measure copper thickness as 
>the industry standard 3 points per side average, which in some cases 
>does not adequately describe the thickness/finished diameter in the 
>working area.
>For verification, from our experience, pin gauging and vertical 
>sections are too uncertain.  Horizontal sections work well.

Most critical is at knee of the hole. That's where insertion forces 
peak while the pin is starting to deform/collapse.  If you've ever 
plotted press fit pin insertion force vs travel (on an Instron or 
such) there's quite a spike in forces right a that point.


>Speed/alignment/ and resultant force should be suspects too.
>
>Chris
>
>
>
>-----Original Message-----
>From: TechNet [mailto:[log in to unmask]] On Behalf Of David D. Hillman
>Sent: Thursday, September 10, 2009 9:53 AM
>To: [log in to unmask]
>Subject: Re: [TN] PTH Cracking with NiAu and Compliant Pin
>
>Hi Brian - the primary cause of plated thru hole cracking using ENIG 
>surface finishes and press-fit/compliant pin technology is incorrect 
>plated thru hole size due to: (a) incorrect fabrication of the 
>plated thru hole; (b) incorrect nickel plating of the plated thru 
>hole; (3) incorrect design dimensioning/tolerancing of the plated 
>thru hole. A secondary cause of plated thru hole cracking would be 
>improper installation force/alignment of the press-fit/compliant pin 
>devices.  If I get a chance, I'll see if I can find the technical 
>article references in our database.
>
>Dave Hillman
>Rockwell Collins
>[log in to unmask]
>
>
>
>
>Brian Chandler <[log in to unmask]> Sent by: TechNet 
><[log in to unmask]>
>09/10/2009 06:42 AM
>Please respond to
>TechNet E-Mail Forum <[log in to unmask]>; Please respond to Brian 
>Chandler <[log in to unmask]>
>
>
>To
>[log in to unmask]
>cc
>
>Subject
>[TN] PTH Cracking with NiAu and Compliant Pin
>
>
>
>
>
>
>Does anyone have any experience or articles with PTH cracking when using
>NiAu board finish with compliant pin? I saw some articles about it a few
>years ago but I cannot find them now.
>
>Thanks in advance,
>
>Brian
>
>---------------------------------------------------
>Technet Mail List provided as a service by IPC using LISTSERV 15.0
>To unsubscribe, send a message to [log in to unmask] with following text in
>the BODY (NOT the subject field): SIGNOFF Technet
>To temporarily halt or (re-start) delivery of Technet send e-mail to
>[log in to unmask]: SET Technet NOMAIL or (MAIL)
>To receive ONE mailing per day of all the posts: send e-mail to
>[log in to unmask]: SET Technet Digest
>Search the archives of previous posts at: http://listserv.ipc.org/archives
>Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16
>for additional information, or contact Keach Sasamori at [log in to unmask] or
>847-615-7100 ext.2815
>-----------------------------------------------------
>
>
>---------------------------------------------------
>Technet Mail List provided as a service by IPC using LISTSERV 15.0
>To unsubscribe, send a message to [log in to unmask] with following text in
>the BODY (NOT the subject field): SIGNOFF Technet
>To temporarily halt or (re-start) delivery of Technet send e-mail to 
>[log in to unmask]: SET Technet NOMAIL or (MAIL)
>To receive ONE mailing per day of all the posts: send e-mail to 
>[log in to unmask]: SET Technet Digest
>Search the archives of previous posts at: http://listserv.ipc.org/archives
>Please visit IPC web site 
>http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional 
>information, or contact Keach Sasamori at [log in to unmask] or 
>847-615-7100 ext.2815
>-----------------------------------------------------
>
>---------------------------------------------------
>Technet Mail List provided as a service by IPC using LISTSERV 15.0
>To unsubscribe, send a message to [log in to unmask] with following text in
>the BODY (NOT the subject field): SIGNOFF Technet
>To temporarily halt or (re-start) delivery of Technet send e-mail to 
>[log in to unmask]: SET Technet NOMAIL or (MAIL)
>To receive ONE mailing per day of all the posts: send e-mail to 
>[log in to unmask]: SET Technet Digest
>Search the archives of previous posts at: http://listserv.ipc.org/archives
>Please visit IPC web site 
>http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional 
>information, or contact Keach Sasamori at [log in to unmask] or 
>847-615-7100 ext.2815
>-----------------------------------------------------

---------------------------------------------------
Technet Mail List provided as a service by IPC using LISTSERV 15.0
To unsubscribe, send a message to [log in to unmask] with following text in
the BODY (NOT the subject field): SIGNOFF Technet
To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL)
To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest
Search the archives of previous posts at: http://listserv.ipc.org/archives
Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815
-----------------------------------------------------