Pillar-to-pillar flip-chip assembly

Details Pillar-to-pillar flip-chip assembly Pillar-to-pillar flip-chip assembly

2008-11-12

2009-08-04

Potter, Roy K (Department: 2822)

Active solid-state devices (e.g., transistors, solid-state diode

Combined with electrical contact or lead

Bump leads

C257S778000, C257SE23021

Reexamination Certificate

active

07569935

ABSTRACT:
A pillar-to-pillar flip-chip assembly primarily comprises a substrate, a chip disposed on the substrate, a plurality of first copper pillars on the bonding pads of the chip, a plurality of second copper pillars on the bump pads of the substrate, and a soldering material. A first height of the first copper pillars protruding from the active surface of the chip is the same as a second height of the second copper pillars from the solder mask on the substrate. When the soldering material electrically and mechanically connects the first copper pillars to the second copper pillars, a plurality of central points of the soldering material are formed on an equal-dividing plane between the chip and the substrate to reduce the direct stresses exerted at the soldering material to avoid peeling or breaks from the bump pads. Moreover, each of conventional solder balls is replaced with two soldered copper pillars to meet the lead-free requirements with higher reliability and lower costs.

REFERENCES:
patent: 5790377 (1998-08-01), Schreiber et al.
patent: 6229220 (2001-05-01), Saitoh et al.
patent: 6578754 (2003-06-01), Tung
patent: 6800169 (2004-10-01), Liu et al.
patent: 7382049 (2008-06-01), Ho et al.

Affiliated with

Also associated with

Rating

Pillar-to-pillar flip-chip assembly does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Pillar-to-pillar flip-chip assembly, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Pillar-to-pillar flip-chip assembly will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-4054533