Methods of removably mounting electronic components to a circuit board, and sockets formed by the methods

• US 20040072456A1
• Filed: 10/10/2003
• Published: 04/15/2004
• Est. Priority Date: 11/16/1993
• Status: Active Grant

• Current Assignee: FormFactor Incorporated
• Original Assignee: FormFactor Incorporated
• Inventors: Mathieu, Gaetan L., Eldridge, Benjamin N., Grube, Gary W., Khandros, Igor Y., Dozier, Thomas H. II
• Granted Patent: US 6,913,468 B2
• Time in Patent Office: Days
• US Class Current: 439/83
• CPC Class Codes: B23K 20/004 Wire welding
• CPC Class Codes: B23K 2101/40 Semiconductor devices
• CPC Class Codes: C25D 21/02 Heating or cooling
• CPC Class Codes: C25D 5/22 Electroplating combined with mechanical treatment during the deposition
• CPC Class Codes: C25D 5/605 Surface topography of the layers, e.g. rough, dendritic or nodular layers
• CPC Class Codes: G01R 1/0483 Sockets for un-leaded IC's having matrix type contact fields, e.g. BGA or PGA devices; Sockets for unpackaged, naked chips for IC's with connecting points around the edges only G01R1/0433
• CPC Class Codes: G01R 1/06711 Probe needles; Cantilever beams; "Bump" contacts; Replaceable probe pins
• CPC Class Codes: G01R 1/07314 the body of the probe being perpendicular to test object, e.g. bed of nails or probe with bump contacts on a rigid support on an elastic support, e.g. a film, G01R1/0735
• CPC Class Codes: G01R 1/07357 with flexible bodies, e.g. buckling beams
• CPC Class Codes: G01R 1/07378 using an intermediate adapter, e.g. space transformers G01R1/07371 takes precedence
• CPC Class Codes: G01R 3/00 Apparatus or processes specially adapted for the manufacture or maintenance of measuring instruments , e.g. of probe tips
• 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 21/4853 Connection or disconnection of other leads to or from a metallisation, e.g. pins, wires, bumps
• CPC Class Codes: H01L 21/4889 Connection or disconnection of other leads to or from wire-like parts, e.g. wires
• CPC Class Codes: H01L 21/563 Encapsulation of active face of flip-chip device, e.g. underfilling or underencapsulation of flip-chip, encapsulation preform on chip or mounting substrate
• CPC Class Codes: H01L 21/76897 Formation of self-aligned vias or contact plugs, i.e. involving a lithographically uncritical step self-aligned silicidation on field effect transistors H01L29/665
• CPC Class Codes: H01L 22/20 Sequence of activities consisting of a plurality of measurements, corrections, marking or sorting steps
• CPC Class Codes: H01L 2224/0615 Mirror array, i.e. array having only a reflection symmetry, i.e. bilateral symmetry
• 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 2224/13639 : Silver [Ag] as principal constituent
• CPC Class Codes: H01L 2224/13644 : Gold [Au] as principal constituent
• CPC Class Codes: H01L 2224/13647 : Copper [Cu] as principal constituent
• CPC Class Codes: H01L 2224/13655 : Nickel [Ni] as principal constituent
• CPC Class Codes: H01L 2224/13657 : Cobalt [Co] as principal constituent
• CPC Class Codes: H01L 2224/16145 : the bodies being stacked
• CPC Class Codes: H01L 2224/45014 : Ribbon connectors, e.g. rectangular cross-section
• 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 2224/4554 : Coating
• CPC Class Codes: H01L 2224/48 : of an individual wire connector
• CPC Class Codes: H01L 2224/49109 : outside the semiconductor or solid-state body
• CPC Class Codes: H01L 2224/73203 : Bump and layer connectors
• CPC Class Codes: H01L 2224/81801 : Soldering or alloying
• CPC Class Codes: H01L 2224/85201 : Compression bonding
• CPC Class Codes: H01L 2224/85205 : Ultrasonic bonding
• CPC Class Codes: H01L 2225/0651 : Wire or wire-like electrical connections from device to substrate
• CPC Class Codes: H01L 2225/06527 : Special adaptation of electrical connections, e.g. rewiring, engineering changes, pressure contacts, layout
• CPC Class Codes: H01L 2225/06555 : Geometry of the stack, e.g. form of the devices, geometry to facilitate stacking
• CPC Class Codes: H01L 2225/06572 : Auxiliary carrier between devices, the carrier having an electrical connection structure
• 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 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 24/16 : of an individual bump connector
• CPC Class Codes: H01L 24/45 : of an individual wire connector
• CPC Class Codes: H01L 24/49 : of a plurality of wire connectors
• CPC Class Codes: H01L 24/72 : Detachable connecting means consisting of mechanical auxiliary parts connecting the device, e.g. pressure contacts using springs or clips
• CPC Class Codes: H01L 24/81 : using a bump connector
• CPC Class Codes: H01L 25/0652 : the devices being arranged next and on each other, i.e. mixed assemblies
• CPC Class Codes: H01L 25/16 : the devices being of types provided for in two or more different main groups of groups H01L27/00 - H01L33/00, or in a single subclass of H10K, H10N, e.g. forming hybrid circuits
• 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 2924/01012 : Magnesium [Mg]
• CPC Class Codes: H01L 2924/01013 : Aluminum [Al]
• CPC Class Codes: H01L 2924/01014 : Silicon [Si]
• CPC Class Codes: H01L 2924/01015 : Phosphorus [P]
• CPC Class Codes: H01L 2924/01019 : Potassium [K]
• CPC Class Codes: H01L 2924/01022 : Titanium [Ti]
• 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 2924/01033 : Arsenic [As]
• CPC Class Codes: H01L 2924/01039 : Yttrium [Y]
• CPC Class Codes: H01L 2924/01042 : Molybdenum [Mo]
• 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 2924/01078 : Platinum [Pt]
• CPC Class Codes: H01L 2924/01079 : Gold [Au]
• CPC Class Codes: H01L 2924/01082 : Lead [Pb]
• 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 2924/10253 : Silicon [Si]
• CPC Class Codes: H01L 2924/10329 : Gallium arsenide [GaAs]
• CPC Class Codes: H01L 2924/12042 : LASER
• CPC Class Codes: H01L 2924/14 : Integrated circuits
• CPC Class Codes: H01L 2924/15311 : being a ball array, e.g. BGA
• CPC Class Codes: H01L 2924/1532 : the connection portion being formed on the die mounting surface of the substrate
• CPC Class Codes: H01L 2924/15787 : Ceramics, e.g. crystalline carbides, nitrides or oxides
• CPC Class Codes: H01L 2924/19041 : being a capacitor
• CPC Class Codes: H01L 2924/206 : Length ranges
• CPC Class Codes: H01L 2924/30107 : Inductance
• CPC Class Codes: H01L 2924/3011 : Impedance
• CPC Class Codes: H01L 2924/3025 : Electromagnetic shielding
• CPC Class Codes: H01R 12/52 : connecting to other rigid printed circuits or like structures
• CPC Class Codes: H05K 1/141 : One or more single auxiliary printed circuits mounted on a main printed circuit, e.g. modules, adapters H05K1/142 and H05K1/147 take precedence
• CPC Class Codes: H05K 2201/0397 : Tab forming integral conductive tabs H05K3/4092
• CPC Class Codes: H05K 2201/068 : wherein the coefficient of thermal expansion is important
• CPC Class Codes: H05K 2201/1031 : Surface mounted metallic connector elements
• CPC Class Codes: H05K 2201/10318 : Surface mounted metallic pins
• CPC Class Codes: H05K 2201/10378 : Interposers
• CPC Class Codes: H05K 2201/10719 : Land grid array [LGA]
• CPC Class Codes: H05K 2201/10734 : Ball grid array [BGA]; Bump grid array
• CPC Class Codes: H05K 2201/10757 : Bent leads
• CPC Class Codes: H05K 2201/10878 : Means for retention of a lead in a hole
• CPC Class Codes: H05K 2201/10909 : Materials of terminal, e.g. of leads or electrodes of components
• CPC Class Codes: H05K 2201/10946 : Leads attached onto leadless component after manufacturing the component
• CPC Class Codes: H05K 3/20 : by affixing prefabricated conductor pattern H05K1/187, H05K3/046, H05K3/4658, H05K3/4682 takes precedence
• CPC Class Codes: H05K 3/308 : Adaptations of leads connectors to printed circuits H01R12/00
• CPC Class Codes: H05K 3/326 : the printed circuit having integral resilient or deformable parts, e.g. tabs or parts of flexible circuits H05K3/365 takes precedence
• CPC Class Codes: H05K 3/3421 : Leaded components
• CPC Class Codes: H05K 3/3426 : characterised by the leads
• CPC Class Codes: H05K 3/368 : parallel to each other H05K3/361 takes precedence
• CPC Class Codes: H05K 3/4015 : using auxiliary conductive elements, e.g. pieces of metal foil, metallic spheres
• CPC Class Codes: H05K 3/4092 : Integral conductive tabs, i.e. conductive parts partly detached from the substrate
• CPC Class Codes: H05K 7/1069 : with spring contact pieces
• CPC Class Codes: Y02P 70/50 : Manufacturing or production processes characterised by the final manufactured product

Abstract

Surface-mount, solder-down sockets are described which permit electronic components such as semiconductor packages to be releasably mounted to a circuit board. Generally, the socket includes resilient contact structures extending from a top surface of a support substrate, and solder-ball (or other suitable) contact structures disposed on a bottom surface of the support substrate. Composite interconnection elements are described for use as the resilient contact structures disposed atop the support substrate. In use, the support substrate is soldered down onto the circuit board, the contact structures on the bottom surface of the support substrate contacting corresponding contact areas on the circuit board. In any suitable manner, selected ones of the resilient contact structures atop the support substrate are connected, via the support substrate, to corresponding ones of the contact structures on the bottom surface of the support substrate. For example, the support substrate is suitably a printed circuit board having plated through holes. In an embodiment intended to receive a LGA-type semiconductor package, pressure contact is made between the resilient contact structures and external connection points of the semiconductor package with a contact force which is generally normal to the top surface of the support substrate. In an embodiment intended to receive a BGA-type semiconductor package, pressure contact is made between the resilient contact structures and external connection points of the semiconductor package with a contact force which is generally parallel to the top surface of the support substrate. Variations of these two basic embodiments are described, including limiting wiping motion of the resilient contact structures across a terminal of an electronic component, and moving the resilient contact structures rather than the electronic component to effect pressure connections therebetween.

Claims

1. Method of removably connecting an electronic component to a circuit board, said circuit board having a plurality of contact areas on a surface thereof, said electronic component having a plurality of terminals on a surface thereof, comprising:

disposing a support substrate between the electronic component and the circuit board, the support substrate having a top surface and a bottom surface opposite the top surface;

mounting a plurality of resilient contact structures to the top surface of the support substrate;

mounting a plurality of contact structures to the bottom surface of the support substrate;

mounting the support substrate to the circuit board so as to make permanent electrical connections between the contact structures and the contact areas;

urging the electronic component against the resilient contact structures so that removable connections are made between the plurality of terminals and the resilient contact structures; and

within the support substrate, interconnecting selected ones of the resilient contact structures with selected ones of the contact structures.

2. Method, according to claim 1, further comprising:

fabricating the resilient contact structures as composite interconnection elements.

3. Method, according to claim 1, further comprising:

forming the contact structures as solder balls.

4. Method, according to claim 1, further comprising:

soldering the contact structures to the contact areas

5. Method, according to claim 1, wherein:

the electronic component is selected from the group consisting of LGA-type semiconductor package, BGA-type semiconductor package and bare semiconductor die.

6. Method, according to claim 1, wherein:

each of the resilient contact structures has a tip; and

the terminals are urged against the tips of the resilient contact structures in a direction which is generally normal to the top surface of the support substrate.

7. Method, according to claim 1, wherein:

each of the resilient contact structures has a tip; and

when the terminals are urged against the tips of the resilient contact structures in a first direction which is generally normal to the top surface of the support substrate, the tips deflect in the first direction to effect a pressure connection between the tips and the terminals and move in a second direction which is generally parallel to the top surface of the support substrate so as to wipe across the pads.

8. Method, according to claim 1, wherein:

each of the resilient contact structures has a tip; and

the terminals are urged against tips of the resilient contact structures in a direction which is generally parallel to the top surface of the support substrate.

9. Solder-down socket, comprising:

a support substrate;

a plurality of resilient contact structures extending upward from a top surface of the support substrate; and

a plurality of solderable raised contact structures disposed on a bottom surface of the substrate, said solderable raised contact structures being electrically connected to the resilient contact structures.

10. Socket, according to claim 9, further comprising:

means for urging an electronic component against tips of the resilient contact structures.

11. Socket, according to claim 10, wherein:

the electronic component is selected from the group consisting of LGA-type semiconductor package, BGA-type semiconductor package and bare semiconductor die.

12. Socket, according to claim 9, wherein:

the resilient contact structures are mounted to the top surface of the support substrate.

13. Socket, according to claim 9, wherein:

end portions of the resilient contact structures extend at least into the support substrate.

14. Socket, according to claim 13, wherein:

the end portions of the resilient contact structures extend through the support substrate.

15. Socket, according to claim 13, wherein:

the solderable raised contact structures are directly connected to ends of the resilient contact structures.

16. Socket, according to claim 13, further comprising:

a plurality of plated through holes extending through the support substrate;

wherein;

the end portions of the resilient contact structures extend into the plated through holes.

17. Socket for releasably connecting an electronic component to a circuit board, comprising:

resilient contact structures extending upward from a top surface of a support substrate

contact structures disposed on a bottom surface of the support substrate and connected through the support substrate to the resilient contact structures.

18. Socket, according to claim 17, wherein:

the resilient contact structures are composite interconnection elements

19. Socket, according to claim 17, further comprising:

a frame element disposed around a peripheral edge of the support substrate.

20. Socket, according to claim 19, further comprising:

means for aligning the frame element in a prescribed positional relationship to the circuit board.

21. Socket, according to claim 20, wherein the means for aligning includes pins extending from the frame element and corresponding holes in the circuit board.

22. Socket, according to claim 17, wherein:

the resilient contact structures are formed as cantilever beams.

23. Socket, according to claim 17, wherein:

the contact structures are solder balls.

24. Socket, cording to claim 17, wherein:

each of the resilient contact structures has a tip; and

further comprising;

a stiffener element disposed above the support substrate having holes through which the tips of the resilient contact structures extend.

25. Socket, according to claim 17, further comprising:

means for urging the electronic component down onto the tips of the resilient contact structures.

26. Socket, according to claim 25, wherein the means for urging includes a spring clip which extends across a top surface of the frame element.

27. Socket, according to claim 17, further comprising:

means for receiving the electronic component on an upper surface thereof, and for permitting the resilient contact structures to make pressure contact with the external connection points of the electronic component, said means for receiving the electronic component having a lower surface opposing the top surface of the support substrate.

28. Socket, according to claim 27, wherein the means for receiving the electronic component is a planar element.

29. Socket, according to claim 28, further comprising:

a plurality of holes extending through the planar element, from the upper surface to the lower surface thereof.

30. Socket, according to claim 29, wherein:

said holes are tapered and have a smaller dimension at the upper surface of the planar element and a larger dimension at the lower surface of the planar element.

31. Socket, according to claim 28, further comprising:

means for moving the planar element in a direction parallel to the top surface of the support substrate to provide an effective pressure contact between the external connection points and the resilient contact structures.

32. Socket, according to claim 17, further comprising:

a frame element disposed around the support substrate;

a planar element disposed above the support substrate, and having at least one hole permitting the tips of the resilient contact structures to pass through the planar element;

a cam lever extending from a cavity in the frame element; and

an offset portion of the cam lever extending through a hole in the planar element.

33. Socket, according to claim 32, further comprising:

at least one recess on an inner surface of the frame element, slidably receiving the planar element.

34. Socket, according to claim 32, wherein:

the resilient contact structures are composite interconnection elements.

35. Socket, according to claim 32, wherein:

the contact structures are solder balls.

36. Socket, according to claim 28, further comprising:

means disposed on the upper surface of the planar element for retaining the electronic component.

37. Socket, according to claim 36, wherein:

the means for retaining is at least three pawls extending upward from the upper surface of the planar element.

38. Socket, according to claim 17, wherein:

the electronic component is selected from the group consisting of LGA-type semiconductor package, BGA-type semiconductor package and bare semiconductor die.

39. Solder-down socket, for making pressure connections to terminals of an electronic component, comprising:

a support substrate having a top surface and a bottom surface;

a plurality of resilient contact structures extending from the top surface of the support substrate, each resilient contact structure having a tip at a free end thereof; and

means for effecting a pressure connection between the tips of the resilient contact structures and the terminals of the electronic component.

40. Solder-down socket, according to claim 39, further comprising:

a plurality of solderable raised contact structure disposed on the bottom surface of the support substrate and connected via the support substrate to the plurality of resilient contact structures.

41. Solder-down socket, according to claim 39, wherein:

the means for effecting a pressure connection moves the terminals of the electronic component against the tips of the resilient contact structures.

42. Solder-down socket, according to claim 39, wherein:

the means for effecting a pressure connection moves the tips of the resilient contact structures against the terminals of thc electronic component

43. Solder-down socket, according to claim 39, further comprising:

means for limiting wiping of the tips of the resilient contact structures across the terminals of the electronic component.

44. Solder-down socket, according to claim 39, wherein:

the electronic component is a bare semiconductor die.

45. Solder-down socket, comprising:

a support substrate having a plurality of holes extending therethrough;

a plurality of pre-fabricated resilient contact structures, each having a base portion and a tip;

the resilient contact structures being supported within the holes in a prescribed spatial relationship with one another by the support substrate; and

a solderable raised contact structure disposed on the base portion of each resilient contact structure.

46. Solder-down socket, according to claim 45, wherein:

the resilient contact structures are composite interconnection elements.

47. Solder-down socket, comprising:

a support substrate having a top surface, a bottom surface and a plurality of holes extending therethrough;

a plurality of metallic pads, each pad having a top surface and a bottom surface, each pad disposed on the bottom surface of the support substrate in alignment with a hole;

a plurality of pre-fabricated resilient contact structures, each having a base portion and a tip;

the base portions of the resilient contact structures being supported in a prescribed spatial relationship with one another by the top surfaces of the metallic pads; and

a solderable raised contact structure disposed on the bottom surface of each metallic pad.

48. Solder-down socket, according to claim 47, wherein:

the resilient contact structures are composite interconnection elements.

49. Interconnection structure for making contact to first terminals of an electronic component, comprising:

a support substrate having a top surface and second terminals disposed on the top surface of the substrate; and

a plurality of resilient contact structures extending generally parallel to one another from each second terminal, the resilient contact structures extending from each second terminal acting in concert with one another to make a pressure connection to a selected one of the first terminals of the electronic component.

50. Interconnection structure, according to claim 49, wherein:

each resilient contact structure has a tip; and

the tips are oriented to make pressure contact with the first terminals of the electronic component with a contact force that is principally generally normal to the top surface of the support substrate.

51. Interconnection structure, according to claim 49, wherein:

each resilient contact structure has a tip; and

the tips are oriented to make pressure contact with the first terminals of the electronic component with a contact force that is generally parallel to the top surface of the support substrate.

52. Interconnection element for making contact to terminals of an electronic component, comprising:

a support substrate having a top surface; and

a plurality of resilient contact structures extending from the top surface of the support substrate, each resilient contact structure having two ends, both ends of each resilient contact structure being attached to the support substrate, a midportion of each resilient contact structure shaped to receive a one of the terminals of the electronic component by pressure contact therewith in a direction which is generally parallel to the top surface of the support substrate.

53. Interconnection element, according to claim 52, wherein:

the electronic component is selected from the group consisting of LGA-type semiconductor package, BGA-type semiconductor package and bare semiconductor die.

54. Interconnection element for making contact to terminals of an electronic component, comprising:

a support substrate having a top surface; and

a plurality of resilient contact structures extending from the top surface of the support substrate, each resilient contact structure having a one end attached to the support substrate and an other end extending above the support substrate, an end portion at the other end of the resilient contact structure shaped in an arcuate manner to receive a terminal of the electronic component by pressure contact therewith in a direction which is generally normal to the top surface of the support substrate.

55. Interconnection element, according to claim 54, wherein:

the electronic component is selected from the group consisting of LGA-type semiconductor package, BGA-type semiconductor package and bare semiconductor die.

56. Solder-down socket, comprising:

a circuit board substrate having a plurality of plated through holes extending through the substrate from a top surface to a bottom surface thereof, each through hole having a top contact area exposed on the top surface of the substrate and a bottom contact area exposed on the bottom surface of the substrate;

a plurality of resilient contact structures mounted to the top contact areas and extending from the top surface of the substrate; and

a plurality of solder balls mounted to the bottom contact areas of the plated through holes.

57. Solder-down socket, comprising:

a support substrate having a plurality of plated through holes extending through the substrate from a top surface to a bottom surface thereof, each through hole having a bottom contact area exposed on the bottom surface of the substrate;

a plurality of resilient contact structures mounted into the plated through holes and extending from the top surface of the substrate; and

a plurality of solder balls mounted to the bottom contact areas of the plated through holes.

58. Solder-down socket, comprising:

a support substrate having a plurality of holes extending through the substrate from a top surface to a bottom surface thereof;

a plurality of resilient contact structures having bottom ends mounted in the holes and top ends extending from the top surface of the substrate; and

a plurality of solder balls mounted to the bottom ends of the resilient contact structures.

59. Solder-down socket, according to claim 58, wherein:

the bottom ends of the resilient contact structures extend completely through the holes, end portions thereof being exposed beneath the bottom surface of the support substrate; and

the solder balls are mounted to the end portions of the resilient contact structures

60. Solder-down socket, comprising:

a support substrate having a top surface and a bottom surface;

a plurality of compliant contact structures extending from the top surface of the support substrate; and

a plurality of solder balls mounted to the bottom surface of the support substrate and connected to the compliant contact structures.

61. Surface-mount socket, comprising:

a support substrate having a top surface and a bottom surface;

a plurality of compliant contact structures extending from the top surface of the support substrate; and

a plurality of solder balls mounted to the bottom surface of the support substrate and connected to the compliant contact structures.