TECHNET Archives

September 2003

TechNet@IPC.ORG
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 >>]

Print Reply
Subject:
Re: 5Sn / 95Pb Solder Sphere
From:
Wei-Shun Wang <[log in to unmask]>
Reply To:
TechNet E-Mail Forum.
Date:
Wed, 24 Sep 2003 13:38:41 -0700
Content-Type:
text/plain
Parts/Attachments:
text/plain (45 lines) 
Hi,

I think the other important reason to use high-temp solder sphere on CBGA is because of the big CTE difference between FR-4 and ceramic. It provide more flexible joint. Same
reason as IBM CCGA packages which use high-temp solder column.

Regards,
Wei Wang

Werner Engelmaier wrote:

> Hi Victor,
> The reason for high-melt solder balls is the same as for solder
> columns--thicker solder connections (higher stand-off heights) provide higher reliability
> roughly by the square of the heights. This is well documented--just take one of
> my workshops.
>
> Regards,
> Werner Engelmaier
> Engelmaier Associates, L.C.
> Electronic Packaging, Interconnection and Reliability Consulting
> 7 Jasmine Run
> Ormond Beach, FL  32174  USA
> Phone: 386-437-8747, Fax: 386-437-8737, Cell: 386-316-5904
> E-mail: [log in to unmask], Website: www.engelmaier.com
>
> ---------------------------------------------------
> Technet Mail List provided as a service by IPC using LISTSERV 1.8e
> 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 847-509-9700 ext.5315
> -----------------------------------------------------

---------------------------------------------------
Technet Mail List provided as a service by IPC using LISTSERV 1.8e
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 847-509-9700 ext.5315
-----------------------------------------------------

ATOM RSS1 RSS2