Method of forming an electrical contact bump

• US 5,090,119 A
• Filed: 10/30/1990
• Issued: 02/25/1992
• Est. Priority Date: 12/08/1987
• Status: Expired due to Term

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Tsuda, Toshio, Bessho, Yoshihiro, Ishida, Toru, Horio, Yasuhiko
• Primary Examiner(s): Arbes, Carl J.
• Application Number:
  US07/605,096
• Time in Patent Office: 483 Days
• Field of Search: 228/4.5, 228/179, 29/747, 29/843, 29/842, 29/844
• US Class Current: 29/843
• CPC Class Codes: H01L 2224/05624 Aluminium [Al] as principal constituent
• CPC Class Codes: H01L 2224/06135 Covering only the peripheral area of the surface to be connected, i.e. peripheral arrangements
• CPC Class Codes: H01L 2224/1134 Stud bumping, i.e. using a wire-bonding apparatus
• CPC Class Codes: H01L 2224/13099 Material
• CPC Class Codes: H01L 2224/13124 Aluminium [Al] as principal constituent
• CPC Class Codes: H01L 2224/13144 Gold [Au] as principal constituent
• CPC Class Codes: H01L 2224/13147 Copper [Cu] as principal constituent
• CPC Class Codes: H01L 2224/16225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/29099 Material
• CPC Class Codes: H01L 2224/45124 Aluminium (Al) as principal constituent
• CPC Class Codes: H01L 2224/45144 Gold (Au) as principal constituent
• CPC Class Codes: H01L 2224/45147 Copper (Cu) as principal constituent
• CPC Class Codes: H01L 2224/48 of an individual wire connector
• CPC Class Codes: H01L 24/11 Manufacturing methods for bumps on insulating substrates H01L21/4853
• CPC Class Codes: H01L 24/12 Structure, shape, material or disposition of the bump connectors prior to the connecting process
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• 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 2924/01005 Boron [B]
• CPC Class Codes: H01L 2924/01006 Carbon [C]
• CPC Class Codes: H01L 2924/01013 : Aluminum [Al]
• CPC Class Codes: H01L 2924/01029 : Copper [Cu]
• CPC Class Codes: H01L 2924/01068 : Erbium [Er]
• CPC Class Codes: H01L 2924/01074 : Tungsten [W]
• CPC Class Codes: H01L 2924/01078 : Platinum [Pt]
• CPC Class Codes: H01L 2924/01079 : Gold [Au]
• CPC Class Codes: H01L 2924/014 : Solder alloys
• CPC Class Codes: H01L 2924/14 : Integrated circuits
• CPC Class Codes: Y10T 29/49149 : by metal fusion bonding
• CPC Class Codes: Y10T 29/49151 : by deforming or shaping

Abstract

A substrate provided with conductive terminals and another substrate provided with electrode pads and two-stepped electrical contact bumps formed respectively on the electrode pads and each consisting of a first raised portion and a second raised portion formed on the first raised portion, are joined securely by bonding the second raised portions coated respectively with droplets of conductive adhesive and the corresponding conductive terminals by the droplets of the conducting adhesive. The ratio of the area of a section of the first raised portion in a plane parallel to the surface of the electrode pad is greater than the area of a section of the second raised portion parallel to the section of the first raised portion at a predetermined ratio. In an exemplary method of forming the electrical contact bump, the second raised portion is formed by bending a conductive wire in a loop by a ball bonding apparatus.

Claims

1. A method of forming, on an electrode pad formed on a substrate, an electrical contact bump having a first raised portion attached to the electrode pad and a second raised portion having a shape of a loop formed on the first raised portion, said method comprising the steps of:

fixedly attaching a ball formed at a free end of a conductive wire held by a capillary to the electrode pad by means of the capillary to form the first raised portion;

looping the conductive wire above the first raised portion to form a looped portion of the conductive wire by means of the capillary, the looped portion having a fixed end connected to the first raised portion and a free end connected to a portion of the conductive wire extending from the capillary;

fixedly attaching the free end of the looped portion of the conductive wire to the first raised portion by means of the capillary; and

cutting the conductive wire extending from the capillary at the free end of the looped portion whereby the second raised portion is formed by the looped portion.

2. A method according to claim 1, wherein the conductive wire is of a material selected from the group consisting of gold, copper and aluminum.

3. A method according to claim 1, wherein the conductive wire comprises an alloy containing, as a main component, a material selected from the group consisting of gold, copper and aluminum.

4. A method off forming, on an electrode pad formed on a substrate, an electrical contact bump having a first raised portion attached to the electrode pad and a second raised portion having a shape of a loop formed on the first raised portion, said method comprising the steps of:

fixedly attaching a ball formed at a free end of a conductive wire held by a capillary to the electrode pad by means of the capillary to form the first raised portion;

looping the conductive wire above the first raised portion to form a looped portion of the conductive wire by means of the capillary, the looped portion having a fixed end connected to the first raised portion and a free end connected to a portion of the conductive wire extending from the capillary;

fixedly attaching the free end of the looped portion of the conductive wire to the electrode pad on which the first raised portion is fixedly attached by means of the capillary; and

cutting the conductive wire at the free end of the looped portion whereby the second raised portion is formed by the looped portion.

5. A method according to claim 4, wherein the conductive wire is of a material selected from the group consisting of gold, copper and aluminum.

6. A method according to claim 4, wherein the conductive wire comprises an alloy containing, as a main component, a material selected from the group consisting of gold, copper and aluminum.