Metal fusion bonding – Process – Preplacing solid filler
Reexamination Certificate
2000-05-24
2001-12-25
Dunn, Tom (Department: 1725)
Metal fusion bonding
Process
Preplacing solid filler
C228S180220, C228S246000, C228S248100, C228S256000
Reexamination Certificate
active
06332569
ABSTRACT:
The invention relates to the providing of precise solder bumps on an integrated circuit element for simultaneous fusing in attachment to circuitry.
BACKGROUND OF THE INVENTION AND RELATION TO THE PRIOR ART
The interconnection technology of semiconductor integrated circuits to circuit bearing substrates has evolved into the use of a technique known as “flip chip” where the interconnection elements are contact bumps that are fused in a first temperature cycle to the precise locations or pads on the integrated circuit element or chip that correspond to specific locations in the corresponding circuit bearing substrate so that the contact bumps support the inverted integrated circuit in position on the substrate during a second temperature cycle where there is simultaneous fusion of all contact bumps to the corresponding circuit locations.
As the “flip chip” art has progressed, the technology has expanded from the considerations involved for individual chips in the direction of the precision necessary for interconnection of complete water areas to broad area circuitry. As the expansion takes place, the number of connections increases, the spacing becomes closer and any differences in interconnection height must be controlled.
Tighter constraints have further become necessary on the volume and type of metal usable in the bump, the response of that metal in the temperature cycles and the ability to perform alignment of the bump contacts to the pads on the chip in the manufacturing operation.
One technique used in the art has been to provide a carrier member for the bump metal increments wherein there is a cavity at each location of a contact bump. The cavity is filled with a metal that under a fusing temperature the surface tension of the liquid metal forms a ball shaped bump. The ball shaped bump in the carrier cavity is then brought into contact with and fused with a corresponding contact pad on the chip. The resulting structure is a ball shaped bump contact on the chip. The technology is described in U.S. Pat. No. 5,607,099.
Another technique in the art involves the use of injection molding of a liquid solder metal into measured volume, precisely located, cavities in a mold plate. The mold plate is then positioned in registration on the pad contact surface of the chip with the metal in each filled cavity in contact with the desired pad location so that a heat cycle fuses the contents of it's respective cavity to the corresponding pad on the chip. The technique is described in copending patent application Ser. No. 08/741,453 filed Oct. 31, 1996, assigned to IBM.
SUMMARY OF THE INVENTION
The invention provides a precise volume, precisely registerable contact bump carrier for use with injection molding in providing bump contacts that are all the same size, the same height and respond identically to heat cycles in the “flip chip” integrated circuit technology.
In the invention, a precise volume, hemispherical cavity, is produced by etching through and undercutting around a registered opening into a transparent carrier. The hemispherical cavity has related specific volume and visible peripheral shape that permits simple optical quality control when the injection molding operation has filled the cavity and simple optical registration for alignment to the pads on the integrated circuit.
REFERENCES:
patent: 3577631 (1971-05-01), Bylander et al.
patent: 4412642 (1983-11-01), Fisher, Jr.
patent: 4473621 (1984-09-01), Drylie
patent: 4839497 (1989-06-01), Sankar et al.
patent: 4906823 (1990-03-01), Kushima et al.
patent: 4914814 (1990-04-01), Behun et al.
patent: 5216807 (1993-06-01), Yoshizawa et al.
patent: 5219117 (1993-06-01), Lin
patent: 5244143 (1993-09-01), Ference et al.
patent: 5346118 (1994-09-01), Degani et al.
patent: 5388327 (1995-02-01), Trabucco
patent: 5607099 (1997-03-01), Yeh et al.
patent: 5643831 (1997-07-01), Ochiai et al.
patent: 5658827 (1997-08-01), Aulicino et al.
patent: 5662262 (1997-09-01), McMahon et al.
patent: 5695109 (1997-12-01), Chiang et al.
patent: 5735452 (1998-04-01), Yu et al.
patent: 5736456 (1998-04-01), Akram
patent: 5770884 (1998-06-01), Pogge et al.
patent: 5775569 (1998-07-01), Berger et al.
patent: 5806753 (1998-09-01), Bielick et al.
patent: 5829668 (1998-11-01), George et al.
patent: 5872051 (1999-02-01), Fallon et al.
patent: 5877079 (1999-03-01), Karasawa et al.
patent: 5909634 (1999-06-01), Hotchkiss et al.
patent: 5950908 (1999-09-01), Fujino et al.
patent: 6025258 (2000-02-01), Ochiai et al.
patent: 6090301 (2000-07-01), Mizukoshi et al.
Herdzik et al. “Tinning Preplated Sites on a Substrate” IBM Technical Disclosure Bullletin, vol. 19, No. 8 Jan. 1977 p. 3049-3050.
“Brazing and Soldering Alloys”, Brochure, Semi-Alloys Inc. MacQues-Ten Parkway, Mount Vernon, N.Y. 5 pages (no date available).
Cordes Steven A.
Gruber Peter Alfred
Kummer Egon Max
Roux Stephen
Sambucetti Carlos Juan
Dunn Tom
International Business Machines - Corporation
Morris David P.
Riddles Alvin J.
Stoner Kiley
LandOfFree
Etched glass solder bump transfer for flip chip integrated... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Etched glass solder bump transfer for flip chip integrated..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Etched glass solder bump transfer for flip chip integrated... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2592245