Method of wirebonding that utilizes a gas flow within a capillary from which a wire is played out

• US 8,485,418 B2
• Filed: 11/09/2010
• Issued: 07/16/2013
• Est. Priority Date: 05/26/1995
• Status: Expired due to Fees

• Current Assignee: FormFactor Incorporated
• Original Assignee: FormFactor Incorporated
• Inventors: Eldridge, Benjamin N., Grube, Gary W., Khandros, Igor Y., Mathieu, Gaetan L.
• Primary Examiner(s): STONER, KILEY SHAWN
• Application Number:
  US12/942,709
• Publication Number:
  US 20110057018A1
• Time in Patent Office: 980 Days
• Field of Search: None
• US Class Current: 228/179.1
• CPC Class Codes: B23K 20/004 Wire welding
• CPC Class Codes: B23K 2101/40 Semiconductor devices
• CPC Class Codes: H01L 2224/45015 being circular
• 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 2224/48091 Arched
• CPC Class Codes: H01L 2224/48227 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/78301 Capillary
• CPC Class Codes: H01L 2224/85043 using a flame torch, e.g. hydrogen torch
• CPC Class Codes: H01L 2224/85045 using a corona discharge, e.g. electronic flame off [EFO]
• CPC Class Codes: H01L 2224/85099 Ambient temperature
• CPC Class Codes: H01L 2224/85203 Thermocompression bonding
• CPC Class Codes: H01L 2224/85205 Ultrasonic bonding
• CPC Class Codes: H01L 2224/85207 Thermosonic bonding
• CPC Class Codes: H01L 23/13 characterised by the shape
• CPC Class Codes: H01L 23/49811 Additional leads joined to the metallisation on the insulating substrate, e.g. pins, bumps, wires, flat leads H01L23/49827 takes precedence
• CPC Class Codes: H01L 23/50 for integrated circuit devices, e.g. power bus, number of leadsH01L23/482 - H01L23/498 take precedence
• 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 24/78 : Apparatus for connecting with wire connectors
• CPC Class Codes: H01L 24/85 : using a wire connector wire bonding in general B23K20/004
• 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 2924/00015 : the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed as prior art
• CPC Class Codes: H01L 2924/01005 : Boron [B]
• CPC Class Codes: H01L 2924/01006 : Carbon [C]
• CPC Class Codes: H01L 2924/01011 : Sodium [Na]
• CPC Class Codes: H01L 2924/01012 : Magnesium [Mg]
• CPC Class Codes: H01L 2924/01014 : Silicon [Si]
• CPC Class Codes: H01L 2924/01015 : Phosphorus [P]
• CPC Class Codes: H01L 2924/01018 : Argon [Ar]
• CPC Class Codes: H01L 2924/01019 : Potassium [K]
• CPC Class Codes: H01L 2924/01023 : Vanadium [V]
• CPC Class Codes: H01L 2924/01027 : Cobalt [Co]
• CPC Class Codes: H01L 2924/01028 : Nickel [Ni]
• CPC Class Codes: H01L 2924/01029 : Copper [Cu]
• CPC Class Codes: H01L 2924/0103 : Zinc [Zn]
• CPC Class Codes: H01L 2924/01033 : Arsenic [As]
• CPC Class Codes: H01L 2924/01042 : Molybdenum [Mo]
• CPC Class Codes: H01L 2924/01044 : Ruthenium [Ru]
• CPC Class Codes: H01L 2924/01045 : Rhodium [Rh]
• CPC Class Codes: H01L 2924/01046 : Palladium [Pd]
• CPC Class Codes: H01L 2924/01047 : Silver [Ag]
• CPC Class Codes: H01L 2924/01049 : Indium [In]
• CPC Class Codes: H01L 2924/0105 : Tin [Sn]
• CPC Class Codes: H01L 2924/01051 : Antimony [Sb]
• CPC Class Codes: H01L 2924/01074 : Tungsten [W]
• CPC Class Codes: H01L 2924/01075 : Rhenium [Re]
• CPC Class Codes: H01L 2924/01076 : Osmium [Os]
• CPC Class Codes: H01L 2924/01077 : Iridium [Ir]
• CPC Class Codes: H01L 2924/01078 : Platinum [Pt]
• CPC Class Codes: H01L 2924/01079 : Gold [Au]
• CPC Class Codes: H01L 2924/01082 : Lead [Pb]
• CPC Class Codes: H01L 2924/013 : Alloys
• CPC Class Codes: H01L 2924/01322 : Eutectic Alloys, i.e. obtained by a liquid transforming into two solid phases
• CPC Class Codes: H01L 2924/014 : Solder alloys
• CPC Class Codes: H01L 2924/07802 : not being an ohmic electrical conductor
• CPC Class Codes: H01L 2924/10253 : Silicon [Si]
• CPC Class Codes: H01L 2924/10329 : Gallium arsenide [GaAs]
• CPC Class Codes: H01L 2924/12041 : LED
• CPC Class Codes: H01L 2924/12044 : OLED
• CPC Class Codes: H01L 2924/14 : Integrated circuits
• CPC Class Codes: H01L 2924/181 : Encapsulation
• CPC Class Codes: H01L 2924/19041 : being a capacitor
• CPC Class Codes: H01L 2924/19043 : being a resistor
• CPC Class Codes: H01L 2924/2075 : larger or equal to 1 micron less than 10 microns
• CPC Class Codes: H01L 2924/20752 : larger or equal to 20 microns less than 30 microns
• CPC Class Codes: H01L 2924/20753 : larger or equal to 30 microns less than 40 microns
• CPC Class Codes: H01L 2924/20754 : larger or equal to 40 microns less than 50 microns
• CPC Class Codes: H01L 2924/20755 : larger or equal to 50 microns less than 60 microns
• CPC Class Codes: H01L 2924/30105 : Capacitance
• CPC Class Codes: H01L 2924/30107 : Inductance
• CPC Class Codes: H01L 2924/3011 : Impedance
• CPC Class Codes: H01L 2924/3025 : Electromagnetic shielding

Abstract

Contact structures exhibiting resilience or compliance for a variety of electronic components are formed. A variety of materials for the wire stem (which serves as a falsework) and for the overcoat (which serves as a superstructure over the falsework) are disclosed. Various techniques are described for mounting the contact structures to a variety of electronic components (e.g., semiconductor wafers and dies, semiconductor packages, interposers, interconnect substrates, etc.), and various process sequences are described. The resilient contact structures described herein are ideal for making a “temporary” (probe) connections to an electronic component such as a semiconductor die, for burn-in and functional testing.

Claims

1. A method of forming a contact assembly comprising:

fabricating a plurality of contact structures each comprising an elongate body that is flexible and resilient;

providing a first substrate comprising an array of electrical connections on a surface of said first substrate; and

after said fabricating step and said providing step, attaching ones of said plurality of contact structures to ones of said electrical connections such that said elongate bodies of said ones of said contact structures extend away from said surface of said first substrate and stand on said first substrate free of material between said elongate bodies that mechanically couples any one of said elongate bodies to any other of said elongate bodies,

wherein said fabricating comprises;

forming said contact structures on a second substrate, and

removing said contact structures from said second substrate.

2. The method of claim 1, wherein said electrical connections comprise metallic pads.

3. The method of claim 1, wherein said forming step comprises sequentially applying a plurality of materials to said second substrate.

4. The method of claim 3, wherein at least one of said materials comprises a patterned layer of material.

5. The method of claim 4, wherein said at least one of said materials comprises photoresist.

6. The method of claim 3, wherein at least one of said materials composes said contact structures.

7. The method of claim 6, wherein a plurality of said materials composes said contact structures.

8. The method of claim 3, wherein at least one of said materials composes tips of said contact structures.

9. The method of claim 8, wherein at least another of said materials composes wires bonded to said tips, said elongate bodies comprising said wires.

10. The method of claim 9, wherein at least another of said materials composes an overcoat at least partially enveloping said wires.

11. The method of claim 8, wherein said tips are patterned.

12. The method of claim 1, wherein said first substrate composes a probe card assembly.

13. The method of claim 1, wherein said attaching step comprises:

bringing ends of said ones of said contact structures into contact with said ones of said electrical connections on said first substrate; and

securing said ends of said ones of said contacts structures to said ones of said electrical connections.

14. The method of claim 1, wherein said attaching step comprises permanently attaching said ones of said plurality of contact structures to said ones of said electrical connections.

15. The method of claim 1, wherein said attaching step comprises metallurgically bonding said ones of said contact structures to said ones of said electrical connections.

16. The method of claim 1, wherein said fabricating step comprises fabricating said plurality of contact structures separate and apart from said first substrate and said electrical connections.

17. The method of claim 16, wherein following said fabricating step and prior to said attaching step said plurality of contact structures are not attached to said electrical connections.

42. The method of claim 1, wherein:

said elongate body of each said contact structure comprises a contact end, and

said elongate body of each of said ones of said contact structures deforms in response to a force on its contact end independently of a force on said contact end of any other of said ones of said contact structures.

18. A method of forming a contact assembly comprising:

providing a first substrate comprising an array of electrical connections on a surface of said first substrate;

fabricating a plurality of elongate contact structures on a second substrate, each said contact structure comprising an elongate body;

after said providing step and said fabricating step, attaching ones of said plurality of contact structures to ones of said electrical connections such that said elongate bodies of said ones of said contact structures extend away from said surface of said first substrate and stand on said first substrate free of material between said elongate bodies that mechanically couples any one of said elongate bodies to any other of said elongate bodies; and

removing said contact structures from said second substrate.

19. The method of claim 18, wherein said fabricating step comprises sequentially applying a plurality of materials to said second substrate.

20. The method of claim 19, wherein at least one of said materials comprises a patterned layer of material.

21. The method of claim 20, wherein said at least one of said materials comprises photoresist.

22. The method of claim 20, wherein at least one of said materials composes said contact structures.

23. The method of claim 22, wherein a plurality of said materials composes said contact structures.

24. The method of claim 23, wherein at least one of said materials composes tips of said contact structures.

25. The method of claim 24, wherein at least another of said materials composes wires bonded to said tips, said elongate bodies comprising said wires.

26. The method of claim 25, wherein at least another of said materials composes an overcoat at least partially enveloping said wires.

27. The method of claim 24, wherein said tips are patterned.

28. The method of claim 18, wherein said fabricating step comprises applying a patterned layer of material to said second substrate, said patterned layer comprising openings corresponding to said contact structures.

29. The method of claim 28, wherein said fabricating step further comprises creating a topographical pattern in said second substrate at said openings.

30. The method of claim 29, wherein said fabricating step further comprises forming contact tips of said contact structures in said openings.

31. The method of claim 30, wherein said step of forming contact tips comprises depositing a material in said openings.

32. The method of claim 31, wherein said step of forming contact tips further comprises depositing a plurality of materials in said openings.

33. The method of claim 30, wherein said fabricating step further comprises wire bonding wires at one end to said tips, second ends of said wires being deposed away from said tips, said elongate bodies comprising said wires.

34. The method of claim 33, wherein said fabricating step further comprises over coating said wires.

35. The method of claim 18, wherein said first substrate composes a probe card assembly.

36. The method of claim 18, wherein said attaching step comprises:

bringing ends of said ones of said contact structures into contact with said ones of said electrical connections on said first substrate; and

securing said ends of said ones of said contacts structures to said ones of said electrical connections.

37. The method of claim 18, wherein said attaching step comprises:

inserting ends of said ones of said contact structures into recesses in said first substrate, said recesses corresponding to said electrical connections on said substrate; and

securing said ends of said ones of said contacts structures in said ones of said recesses.

38. The method of claim 18, wherein said fabricating step comprises fabricating said plurality of contact structures separate and apart from said first substrate and said electrical connections.

39. The method of claim 38, wherein following said fabricating step and prior to said attaching step said plurality of contact structures are not attached to said electrical connections.

40. The method of claim 18, wherein said attaching comprises attaching said contact structures to said electrical connections such that said elongate body of each of said contact structure is disposed entirely to one side of said first substrate.

41. The method of claim 18, wherein:

said elongate body of each said contact structure comprises a contact end, and

said elongate body of said ones of said contact structures deforms in response to a force on its contact end independently of a force on said contact end of any other of said ones of said contact structures.