[tinwhiskers] Re: Re-balling SAC BGAs

  • From: Norman Dancer <ndancer@xxxxxxxxxxxxxxxxxxx>
  • To: "tinwhiskers@xxxxxxxxxxxxx" <tinwhiskers@xxxxxxxxxxxxx>
  • Date: Fri, 30 Jul 2010 15:10:00 -0700

                Let's see.  A tin whisker prevention process.

                Step 1 - boil ROHS in molten lead.
                Step 2 - add  lead to tin in the ratio of 37% by weight.
                Step 3 - voila, we've solved a modern problem solved by tin 
workers in the bronze age.  Woohoo!  Progress!

Norman Dancer
Senior Engineer
350 Holger Way
San Jose, CA 95134 USA
Tel: 408-571-3646 Fax: 408-571-3550
www.force10networks.com<http://www.force10networks.com>
From: tinwhiskers-bounce@xxxxxxxxxxxxx 
[mailto:tinwhiskers-bounce@xxxxxxxxxxxxx] On Behalf Of Bob Landman
Sent: Friday, July 30, 2010 1:53 PM
To: tinwhiskers@xxxxxxxxxxxxx
Subject: [tinwhiskers] Re: Re-balling SAC BGAs

Hi Mordechai!

I have not forgotten you need the questions posted on vias in pads  - I've just 
been overloaded with work and it keeps slipping down the stack...

I will let you know who does the work and how it is when/if we do it.  There's 
another part we might use which is available in tin/lead.

Getting close to filing the patent on a tin whisker prevention process - when 
we do I'll send you a copy.

Bob

________________________________
From: tinwhiskers-bounce@xxxxxxxxxxxxx 
[mailto:tinwhiskers-bounce@xxxxxxxxxxxxx] On Behalf Of Mordechai Kirshenbaum
Sent: Friday, July 30, 2010 11:49 AM
To: tinwhiskers@xxxxxxxxxxxxx
Subject: [tinwhiskers] Re: Re-balling SAC BGAs
Hi Bob

We tried to arrange a visiting at their production lines, but we encounter
many difficulties, since they say they need an approval from the Department of 
State
(I think they call it ITAR).

If you are going to use their service please let me know about  your impression 
of  the re-balling quality.

Bye

Mordechai

________________________________
From: Bob Landman <rlandman@xxxxxxxxxxxxxxxxx>
To: tinwhiskers@xxxxxxxxxxxxx
Sent: Fri, July 30, 2010 4:26:52 PM
Subject: [tinwhiskers] Re: Re-balling SAC BGAs

I will do that now.  Several friends have suggested their service.  Meant to 
contact them - thanks for the reminder.

I have a quote from Premier Semi and one other firm.  Since our assembly work 
is in Silicon Valley, it would be very convenient, if the cost is right, to use 
them.

Bob

-----Original Message-----
From: tinwhiskers-bounce@xxxxxxxxxxxxx<mailto:tinwhiskers-bounce@xxxxxxxxxxxxx> 
[mailto:tinwhiskers-bounce@xxxxxxxxxxxxx<mailto:tinwhiskers-bounce@xxxxxxxxxxxxx>]
 On Behalf Of Gary VanRemortel
Sent: Thursday, July 29, 2010 3:58 PM
To: tinwhiskers@xxxxxxxxxxxxx<mailto:tinwhiskers@xxxxxxxxxxxxx>
Subject: [tinwhiskers] Re: Re-balling SAC BGAs

Check in with Six Sigma (a division of Winslow Automation), we deal with the 
reballing group in Milpitas, CA 408-956-0100, and talk with them.

G. VanRemortel
Senior Mechanical Engineer
CPU Technology, Inc (r)
5731 W. Las Positas Blvd
Pleasanton, CA 94588
(925) 224-9920 (Voice)
(925) 227-0539 (Fax)
(408) 375-4450 (Cell)
www.cputech.com<http://www.cputech.com/>
************************************************
CONFIDENTIALITY NOTICE
The information contained in this transmission is intended only for the person 
or entity to which it is addressed and may contain confidential and/or 
privileged material.  If you are not the intended recipient of this 
information, do not review, retransmit, disclose, disseminate, use, or take any 
action in reliance upon this information.  If you received this transmission in 
error, please contact the sender and destroy all printed copies and delete the 
material from all computers.

************************************************
"Insanity in individuals is something rare, but in groups, parties, nations and 
epochs it is the rule" -Nietzsche


-----Original Message-----
From: tinwhiskers-bounce@xxxxxxxxxxxxx<mailto:tinwhiskers-bounce@xxxxxxxxxxxxx> 
[mailto:tinwhiskers-bounce@xxxxxxxxxxxxx<mailto:tinwhiskers-bounce@xxxxxxxxxxxxx>]
 On Behalf Of Bob Landman
Sent: Thursday, July 29, 2010 12:40 PM
To: tinwhiskers@xxxxxxxxxxxxx<mailto:tinwhiskers@xxxxxxxxxxxxx>
Subject: [tinwhiskers] Re-balling SAC BGAs

Here's one bit of information:

I'm planning to re-ball a new 484 ball BGA part we will be using since Lattice 
Semiconductor refuses to make the part in tin/lead.  I have investigated the 
options and it is very clear to me that using tin/lead solderpaste with 
lead-free solderballs is a no-no.

Polina Snugovsky at Celestica has studied this subject a lot and it's clear 
from her paper that the process reflow window is very tight (you have to raise 
the temp to melt the SAC balls).  Too risky.

http://www.hlinstruments.com//RoHS_articles/Solder%20Joint%20Reliability%20of%20Pb-free%20Sn-Ag-Cu%20BGA%20in%20SnPb.pdf

Now if I can just get some parts in less than 22 weeks!

Not happy about this situation; Lattice seems to have me by the .....

Bob Landman
H&L Instruments, LLC

-----Original Message-----
From: tinwhiskers-bounce@xxxxxxxxxxxxx<mailto:tinwhiskers-bounce@xxxxxxxxxxxxx> 
[mailto:tinwhiskers-bounce@xxxxxxxxxxxxx<mailto:tinwhiskers-bounce@xxxxxxxxxxxxx>]
 On Behalf Of Rod
Sent: Thursday, July 29, 2010 9:24 AM
To: tinwhiskers@xxxxxxxxxxxxx<mailto:tinwhiskers@xxxxxxxxxxxxx>
Subject: [tinwhiskers] Re: Not receiving any email's re tin whiskers for the 
last two months


On 29 Jul 2010, at 01:19, Randall Miller wrote:

> Me neither, but I didn't notice until you mentioned it.
> There are always plenty of things to occupy my feeble brain to not
> notice something missing.

Well, it depends on someone finding something worth saying.

regards,  Rod

rod.dalitz@xxxxxxxxxxxxxxxx<mailto:rod.dalitz@xxxxxxxxxxxxxxxx>










Other related posts: