Method for forming contact pins for semiconductor dice and interconnects

• US 5,495,667 A
• Filed: 11/07/1994
• Issued: 03/05/1996
• Est. Priority Date: 11/07/1994
• Status: Expired due to Term

• Current Assignee: Micron Technology, Inc.
• Original Assignee: Micron Technology, Inc.
• Inventors: Farnworth, Warren M., Wood, Alan G., Akram, Salman
• Primary Examiner(s): Arbes, Carl J.
• Application Number:
  US08/335,262
• Time in Patent Office: 484 Days
• Field of Search: 427/96, 257/784, 437/8, 228/4.5, 29/843
• US Class Current: 29/843
• CPC Class Codes: G01R 1/06 Measuring leads; Measuring probes G01R19/145, G01R19/165 take precedence
• CPC Class Codes: G01R 31/2884 using dedicated test connectors, test elements or test circuits on the IC under test G01R31/2855 takes precedence
• CPC Class Codes: G01R 31/2886 Features relating to contacting the IC under test, e.g. probe heads; chucks G01R31/2865 takes precedence, test connections, e.g. test sockets, or probes per se, G01R1/04 or G01R1/06
• CPC Class Codes: H01L 2224/0401 Bonding areas specifically adapted for bump connectors, e.g. under bump metallisation [UBM]
• CPC Class Codes: H01L 2224/04042 Bonding areas specifically adapted for wire connectors, e.g. wirebond pads
• CPC Class Codes: H01L 2224/05568 the whole external layer protruding from the surface
• CPC Class Codes: H01L 2224/056 with a principal constituent of the material being a metal or a metalloid, e.g. boron [B], silicon [Si], germanium [Ge], arsenic [As], antimony [Sb], tellurium [Te] and polonium [Po], and alloys thereof
• CPC Class Codes: H01L 2224/05624 Aluminium [Al] as principal constituent
• CPC Class Codes: H01L 2224/05644 Gold [Au] as principal constituent
• CPC Class Codes: H01L 2224/05655 Nickel [Ni] as principal constituent
• 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 2224/13155 Nickel [Ni] as principal constituent
• CPC Class Codes: H01L 2224/451 with a principal constituent of the material being a metal or a metalloid, e.g. boron (B), silicon (Si), germanium (Ge), arsenic (As), antimony (Sb), tellurium (Te) and polonium (Po), and alloys thereof
• 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 2224/45155 : Nickel (Ni) as principal constituent
• CPC Class Codes: H01L 2224/48463 : the connecting portion on the bonding area of the semiconductor or solid-state body being a ball bond
• CPC Class Codes: H01L 2224/48624 : Aluminium (Al) as principal constituent
• CPC Class Codes: H01L 2224/48644 : Gold (Au) as principal constituent
• CPC Class Codes: H01L 2224/48655 : Nickel (Ni) as principal constituent
• CPC Class Codes: H01L 2224/48724 : Aluminium (Al) as principal constituent
• CPC Class Codes: H01L 2224/48744 : Gold (Au) as principal constituent
• CPC Class Codes: H01L 2224/48755 : Nickel (Ni) as principal constituent
• CPC Class Codes: H01L 2224/48824 : Aluminium (Al) as principal constituent
• CPC Class Codes: H01L 2224/48844 : Gold (Au) as principal constituent
• CPC Class Codes: H01L 2224/48855 : Nickel (Ni) as principal constituent
• CPC Class Codes: H01L 2224/742 : Apparatus for manufacturing bump connectors
• CPC Class Codes: H01L 2224/78301 : Capillary
• CPC Class Codes: H01L 24/05 : of an individual bonding area
• 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 24/13 : of an individual bump connector
• CPC Class Codes: H01L 24/16 : of an individual bump connector
• CPC Class Codes: H01L 24/45 : of an individual wire connector
• CPC Class Codes: H01L 24/48 : of an individual wire connector
• CPC Class Codes: H01L 24/742 : Apparatus for manufacturing bump connectors
• 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 2924/00012 : Relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• 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 2924/01014 : Silicon [Si]
• CPC Class Codes: H01L 2924/01028 : Nickel [Ni]
• CPC Class Codes: H01L 2924/01029 : Copper [Cu]
• CPC Class Codes: H01L 2924/01039 : Yttrium [Y]
• 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 2924/10253 : Silicon [Si]
• CPC Class Codes: H01L 2924/12042 : LASER
• CPC Class Codes: H01L 2924/14 : Integrated circuits
• CPC Class Codes: H05K 3/328 : by welding
• CPC Class Codes: Y10T 29/49149 : by metal fusion bonding

Abstract

A method for forming contact pins adapted to form an electrical connection with a mating contact location is provided. In a first embodiment, the contact pins are formed on an interconnect used for testing a semiconductor die and are adapted to establish an electrical connection with the bond pads of the die. In a second embodiment, the contact pins are formed directly on the bond pads of a die and can be used for establishing a permanent or temporary electrical connection to the pads. The contact pins include a base portion attached to the die or interconnect, a compliant spring segment, and a contact ball at the tip. The contact pins are formed using a wire bonding process or a welding process in which a metal wire is simultaneously heated and shaped into a compliant structure as it is attached to the die or interconnect.

Claims

1. A method for forming a contact structure on an interconnect, said contact structure adapted to establish an electrical connection with a contact location on a semiconductor die, said method comprising:

providing a substrate;

attaching a wire to the substrate using a method selected from the group consisting of wire bonding and welding;

heating and shaping the wire into a compliant structure during said attaching step; and

severing the wire to form a contact pin.

2. The method as claimed in claim 1 and wherein:

heating and shaping the wire is with a laser and a wire bonder tool manipulated to bend the wire into a predetermined shape.

3. The method as claimed in claim 1 and wherein:

heating and shaping the wire is with a heated capillary tube.

4. The method as claimed in claim 1 and wherein:

the wire is shaped to include a spring segment.

5. The method as claimed in claim 1 and wherein:

the wire is shaped with a contact ball on an end thereof.

6. A method for forming a contact pin for an interconnect, said contact pin adapted to establish an electrical connection with a contact location on a semiconductor die, comprising:

forming a substrate;

forming a conductive trace on the substrate;

attaching a metal pin to the substrate in electrical communication with the conductive trace said metal pin formed of a wire that is attached to the substrate using an attachment method selected from the group consisting of wire bonding and welding;

heating and shaping the wire as it is attached to the substrate to form a compliant spring segment; and

following heating and shaping of the wire severing the wire.

7. The method as claimed in claim 6 and wherein;

the compliant spring segment is c-shaped.

8. The method as claimed in claim 6 and wherein:

the compliant spring segment is s-shaped.

9. The method as claimed in claim 6 and wherein:

the spring segment is wider at a base.

10. The method as claimed in claim 6 and wherein:

the wire is attached to the substrate at an acute angle with respect to a plane of the substrate.

11. The method as claimed in claim 6 and further comprising:

forming a contact ball on an end of the length of wire.

12. A method for forming a contact pin for an interconnect, said contact pin adapted to establish an electrical connection with a contact location on a semiconductor die, comprising:

forming a substrate;

forming a conductive trace on the substrate;

attaching a metal pin to the substrate in electrical communication with the conductive trace, said metal pin formed of a wire that is wire bonded to the substrate;

heating and shaping the wire as it is wire bonded to form a compliant spring segment; and

then

severing the wire.

13. The method as claimed in claim 12 and wherein;

heating and shaping the wire is by manipulating a wire bonding tool while a laser heats the wire.

14. The method as claimed in claim 12 and wherein:

heating and shaping the wire is by manipulating a capillary tube having a heating element.

15. The method as claimed in claim 12 and wherein:

the spring segment is attached to the substrate at an acute angle with respect to a plane of the substrate.

16. The method as claimed in claim 12 and wherein:

the spring segment is wider at a base than at a tip.

17. The method as claimed in claim 12 and further comprising:

forming a ball on an end of the wire.

18. The method as claimed in claim 12 and wherein:

the conductive trace includes a bond site and the wire is wire bonded to the bond site.

19. A method for forming a contact structure on a semiconductor die, said die including a substrate with integrated circuitry and a die pad in electrical communication with the integrated circuitry, said method comprising:

forming a solder pad on the die pad;

attaching a metal wire to the solder pad using a wire bonding process;

heating and shaping the wire into a compliant structure during said wire bonding process; and

after shaping the wire, severing the wire to form a compliant contact pin on the die pad.

20. The method as claimed in claim 19 and wherein:

the metal wire is attached to the substrate at an acute angle with respect to a plane of the substrate to provide the compliant structure.

21. The method as claimed in claim 19 and further comprising:

heating and shaping the metal wire with a spring segment as it is attached to the solder pad to provide the compliant structure.

22. The method as claimed in claim 19 and further comprising:

forming a contact ball on an end of the metal wire.

23. The method as claimed in claim 19 and wherein:

heating the metal wire is with a laser and shaping the metal wire is by manipulating a wire bonding tool.

24. The method as claimed in claim 19 and wherein:

heating and shaping the metal wire is with a heated capillary tool.

25. A method for forming a contact structure on a semiconductor die having a plurality of die pads in electrical communication with integrated circuitry formed on the die, said method comprising:

forming a mask on the substrate having an opening aligned with the die pads;

forming a shorting layer on the substrate to electrically connect the die pads;

forming welding pads in the openings in electrical contact with the die pads;

attaching metal wires to the welding pads using a welding process;

heating and shaping the metal wires during the welding process into a compliant structure;

severing the metal wire to form contact pins; and

removing the shorting layer except in an area in contact with the welding pads.

26. The method as claimed in claim 25 and wherein:

the metal wires are attached to the substrate at an acute angle with respect to a plane of the substrate.

27. The method as claimed in claim 25 and wherein:

the contact pins are formed with a spring segment during the heating and shaping step.

28. The method as claimed in claim 25 and further comprising:

forming a ball on an end of the contact pins.

29. The method as claimed in claim 25 and wherein:

heating the metal wire is with a laser.

30. The method as claimed in claim 25 and wherein:

heating and shaping the metal wire is with a heated capillary tool.