Which I believe actually describes a larger version of ACF bonding of a flip
chip....................?

John
 
 
John Burke
 
(408) 515 4992

-----Original Message-----
From: Leadfree [mailto:[log in to unmask]] On Behalf Of Joe Fjelstad
Sent: Wednesday, March 07, 2007 12:21 PM
To: [log in to unmask]
Subject: Re: [LF] Polymer Core BGA Balls

Hi Richard, 
 
Thanks for the link. It appears that Motorola's focus and claims were
around 
a polymer column.  
 
Tessera disclosed and patented a polymer ball concept in the same  general 
time frame. 
 
The operative sentence is "each conductive element 26 incorporates a  
flexible body 28 covered by a thin, flexible conductive shell 30"  
 
The first claim reads

1. A method of making a semiconductor chip assembly comprising the  steps
of: 

(a) providing a plurality of deformable electrically  conductive elements, 
each including a thin, flexible metallic shell extending  over at least a 
portion of the surface of the conductive element, and mounting  said
conductive 
elements to contacts on a chip so that the metallic shells are  exposed;
then 

(b) connecting the chip to a substrate by metallurgically  bonding the 
conductive elements to contact pads on the substrate. 

I suspect that there are a number of other concepts out there as well. 
 
Very best, 
Joe
<BR><BR><BR>**************************************<BR> AOL now offers free 
email to everyone.  Find out more about what's free from AOL at 
http://www.aol.com.

----------------------------------------------------------------------------
---Leadfee Mail List provided as a service by IPC using LISTSERV 1.8d
To unsubscribe, send a message to [log in to unmask] with following text in
the BODY (NOT the subject field): SIGNOFF Leadfree
To temporarily stop/(start) delivery of Leadree for vacation breaks send:
SET Leadfree NOMAIL/(MAIL)
Search previous postings 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
----------------------------------------------------------------------------
---

-------------------------------------------------------------------------------Leadfee Mail List provided as a service by IPC using LISTSERV 1.8d
To unsubscribe, send a message to [log in to unmask] with following text in
the BODY (NOT the subject field): SIGNOFF Leadfree
To temporarily stop/(start) delivery of Leadree for vacation breaks send: SET Leadfree NOMAIL/(MAIL)
Search previous postings 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
-------------------------------------------------------------------------------