Yes Ben, with these alloy combinations, we encountered cracks on their
interfaces during precon level 1 + 100 cycles TMCL (-65 to 150). It would
become a weak point in your joints. our Alloy is 95Pb/Sn + SAC solder. It is
much higher lead than yours.

regards


On 6/26/08, Gumpert, Ben <[log in to unmask]> wrote:
>
>
> Jonathan,
>
> The balls are already attached, this is a component as provided by the
> vendor.
>
> Your comments about reliability are what I am looking for, and I am
> seeing the same thing that you describe - increased diffusion of the
> ball at the SAC/Pb90Sn10 interface when compared to a Sn63Pb37/Pb90Sn10
> interface.
>
> The balls have not reached the point of collapsing, likely because we
> subjected them only to a Pb reflow profile.
>
> Ben
>
> -----Original Message-----
> From: TechNet [mailto:[log in to unmask]] On Behalf Of jonathan noquil
> Sent: Tuesday, June 24, 2008 11:05 PM
> To: [log in to unmask]
> Subject: Re: [TN] SAC solder on Pb90Sn10
>
> Hi Ben:
> Why not use flux to attach the balls?
> If you use solder it could alter somehow your ball diameter and ball
> property since SAC solder is Sn rich and your ball is high lead. Pb will
> react with Sn and gradually affect the solder joint property between
> solderball and SAC solder (This is a reliability risk).
> In the past we have tried this and our solder ball collapsed due to Sn
> and Pb reaction, but since your BGA solder mask defined, maybe you can
> maintain your ball height but i doubt if you can maintain ball
> uniformity/planarity
>
> regards
> J.Noquil
> Senior Member Technical Staff
> CSD
>
>
>
>
> On 6/25/08, Stadem, Richard D. <[log in to unmask]> wrote:
> >
> > Hi, Ben
> > Good question. I checked with the Power PC data sheets
> > http://ieeexplore.ieee.org/iel3/3906/11336/00514354.pdf?arnumber=51435
> > 4 and they do not specify how they attach their 90/10 balls to the
> > package, but I suspect some type of high-temp alloy is used. I do not
> > believe they reflow the balls directly to the package pads. But I
> > never did know what they use to solder the balls to the package with.
> > Let me know if you find out.
> >
> >
> >
> > -----Original Message-----
> > From: TechNet [mailto:[log in to unmask]] On Behalf Of Gumpert, Ben
> > Sent: Tuesday, June 24, 2008 12:42 PM
> > To: [log in to unmask]
> > Subject: [TN] SAC solder on Pb90Sn10
> >
> > Technetters,
> >
> > Does anyone have any experience (or heard of) using SAC solder to
> > attach high-temp (Pb90Sn10) solder balls to a ceramic BGA?
> >
> > Ben
> >
> >
> > ---------------------------------------------------
> > 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=4.3.16for 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=4.3.16for 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
-----------------------------------------------------