SOLDER JOINTS WITH ENHANCED ELECTROMIGRATION RESISTANCE

• US 20100155947A1
• Filed: 12/24/2008
• Published: 06/24/2010
• Est. Priority Date: 12/24/2008
• Status: Active Grant

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: GURUMURTHY, Charan, PANG, Mengzhi, Pilin, Liu
• Granted Patent: US 8,013,444 B2
• Time in Patent Office: Days
• US Class Current: 257/741
• CPC Class Codes: B23K 2101/36 Electric or electronic devices
• CPC Class Codes: B23K 35/262 Sn as the principal constituent
• CPC Class Codes: H01L 2224/0401 Bonding areas specifically adapted for bump connectors, e.g. under bump metallisation [UBM]
• CPC Class Codes: H01L 2224/05099 Material
• CPC Class Codes: H01L 2224/05599 Material
• CPC Class Codes: H01L 2224/05647 Copper [Cu] as principal constituent
• CPC Class Codes: H01L 2224/05655 Nickel [Ni] as principal constituent
• CPC Class Codes: H01L 2224/13099 Material
• CPC Class Codes: H01L 2224/13111 Tin [Sn] as principal constituent
• CPC Class Codes: H01L 2224/13599 Material
• CPC Class Codes: H01L 2224/16 of an individual bump connector
• CPC Class Codes: H01L 2224/16225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/16227 the bump connector connecting to a bond pad of the item
• CPC Class Codes: H01L 2224/29099 Material
• CPC Class Codes: H01L 2224/29599 Material
• CPC Class Codes: H01L 2224/73204 the bump connector being embedded into the layer connector
• CPC Class Codes: H01L 2224/81815 Reflow soldering
• CPC Class Codes: H01L 24/13 of an individual bump connector
• CPC Class Codes: H01L 24/16 of an individual bump connector
• CPC Class Codes: H01L 2924/00013 Fully indexed content
• CPC Class Codes: H01L 2924/00014 : the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/01015 : Phosphorus [P]
• CPC Class Codes: H01L 2924/01027 : Cobalt [Co]
• CPC Class Codes: H01L 2924/01029 : Copper [Cu]
• CPC Class Codes: H01L 2924/01047 : Silver [Ag]
• CPC Class Codes: H01L 2924/01083 : Bismuth [Bi]
• CPC Class Codes: H01L 2924/01327 : Intermediate phases, i.e. intermetallics compounds
• CPC Class Codes: H01L 2924/14 : Integrated circuits
• CPC Class Codes: Y10T 428/12708 : Sn-base component

Abstract

Electronic assemblies and solders used in electronic assemblies are described. One embodiment includes a die and a substrate, with a solder material positioned between the die and the substrate, the solder comprising at least 91 weight percent Sn, 0.4 to 1.0 weight percent Cu and at least one dopant selected from the group consisting of Ag, Bi, P, and Co. Other embodiments are described and claimed.

Claims

3-1. The device of claim 1, wherein the solder material consists of:

0.4 to 1.0 weight percent Cu;

greater than 0 and up to 2 weight percent Ag;

greater than 0 and up to 2 weight percent Bi; and

the balance being Sn and unavoidable impurities.

13. A method comprising:

providing a solder material on at least one of a substrate and a die, the solder material comprising Sn, 0.4 to 1.0 weight percent of Cu, and at least one dopant selected from the group consisting of Ag, Bi, P, Co;

heating the solder material to a temperature so that it reflows;

coupling the die and substrate together through the solder material; and

solidifying the solder material after the reflow;

wherein the coupling the die and substrate together is carried out using a method selected from the group consisting of;

coupling the die and substrate together through the solder prior the reflow, and coupling the die and substrate together through the solder after the solder reflow.

14. The method of claim 13, wherein the solder material consists of:

0.4 to 1.0 weight percent Cu;

greater than 0 and up to 2 weight percent Ag;

greater than 0 and up to 2 weight percent Co; and

the balance being Sn and unavoidable impurities.

15. The method of claim 14, wherein the Co is present in an amount of 1.0 to 2.0 weight percent.