Method for manufacturing raised electrical contact pattern of controlled geometry

• US 6,538,214 B2
• Filed: 05/04/2001
• Issued: 03/25/2003
• Est. Priority Date: 11/16/1993
• Status: Expired due to Fees

• Current Assignee: FormFactor Incorporated
• Original Assignee: FormFactor Incorporated
• Inventors: Khandros, Igor Y.
• Primary Examiner(s): Paladini, Albert W.
• Assistant Examiner(s): Vigushin, John B.
• Application Number:
  US09/848,854
• Publication Number:
  US 20020023773A1
• Time in Patent Office: 690 Days
• Field of Search: 361/767, 361/774, 361/776, 361/772, 361/773, 439/66, 439/83, 439/876, 439/886, 439/887, 439/78, 439/81, 174/267, 298/42, 298/43, 298/74, 298/84, 298/85, 298/969
• US Class Current: 174/267
• CPC Class Codes: B23K 1/0016 Brazing of electronic components
• CPC Class Codes: B23K 2101/40 Semiconductor devices
• CPC Class Codes: C23C 18/161 from plating step, e.g. inkjet
• CPC Class Codes: C25D 7/12 Semiconductors
• CPC Class Codes: C25D 7/123 Semiconductors first coated with a seed layer or a conductive layer
• CPC Class Codes: G01R 1/0466 concerning contact pieces or mechanical details, e.g. hinges or cams; Shielding
• CPC Class Codes: G01R 1/06711 Probe needles; Cantilever beams; "Bump" contacts; Replaceable probe pins
• CPC Class Codes: G01R 1/06761 related to layers
• CPC Class Codes: G01R 1/07307 with individual probe elements, e.g. needles, cantilever beams or bump contacts, fixed in relation to each other, e.g. bed of nails fixture or probe card
• 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 31/2884 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 21/4853 Connection or disconnection of other leads to or from a metallisation, e.g. pins, wires, bumps
• 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 21/6715 Apparatus for applying a liquid, a resin, an ink or the like H01L21/67126 takes precedence
• 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 2224/10126 Bump collar
• CPC Class Codes: H01L 2224/10145 Flow barriers
• 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 2224/13111 : Tin [Sn] as principal constituent
• CPC Class Codes: H01L 2224/29099 : Material
• CPC Class Codes: H01L 2224/32225 : the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/45015 : being circular
• CPC Class Codes: H01L 2224/45109 : Indium (In) as principal constituent
• CPC Class Codes: H01L 2224/45111 : Tin (Sn) as principal constituent
• CPC Class Codes: H01L 2224/45116 : Lead (Pb) as principal constituent
• CPC Class Codes: H01L 2224/45117 : the principal constituent melting at a temperature of greater than or equal to 400°C and less than 950°C
• CPC Class Codes: H01L 2224/4512 : Antimony (Sb) as principal constituent
• CPC Class Codes: H01L 2224/45123 : Magnesium (Mg) as principal constituent
• CPC Class Codes: H01L 2224/45124 : Aluminium (Al) as principal constituent
• CPC Class Codes: H01L 2224/45138 : the principal constituent melting at a temperature of greater than or equal to 950°C and less than 1550°C
• CPC Class Codes: H01L 2224/45139 : Silver (Ag) 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 2224/45163 : the principal constituent melting at a temperature of greater than 1550°C
• CPC Class Codes: H01L 2224/45164 : Palladium (Pd) as principal constituent
• CPC Class Codes: H01L 2224/45169 : Platinum (Pt) as principal constituent
• CPC Class Codes: H01L 2224/45173 : Rhodium (Rh) as principal constituent
• CPC Class Codes: H01L 2224/45176 : Ruthenium (Ru) as principal constituent
• CPC Class Codes: H01L 2224/4554 : Coating
• CPC Class Codes: H01L 2224/4556 : Disposition, e.g. coating on a part of the core
• CPC Class Codes: H01L 2224/456 : 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 2224/4809 : Loop shape
• CPC Class Codes: H01L 2224/48091 : Arched
• CPC Class Codes: H01L 2224/4813 : Connecting within a semiconductor or solid-state body, i.e. fly wire, bridge wire
• CPC Class Codes: H01L 2224/48227 : connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/48465 : the other connecting portion not on the bonding area being a wedge bond, i.e. ball-to-wedge, regular stitch
• 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 2224/73265 : Layer and wire connectors
• CPC Class Codes: H01L 2224/78301 : Capillary
• CPC Class Codes: H01L 2224/81205 : Ultrasonic bonding
• CPC Class Codes: H01L 2224/81801 : Soldering or alloying
• 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 2224/85201 : Compression bonding
• CPC Class Codes: H01L 2224/85205 : Ultrasonic bonding
• 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 24/13 : of an individual bump connector
• CPC Class Codes: H01L 24/16 : of an individual bump connector
• CPC Class Codes: H01L 24/29 : of an individual layer 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 24/49 : 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 2924/00012 : 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 2924/00015 : 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 2924/01011 : Sodium [Na]
• 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 2924/0102 : Calcium [Ca]
• CPC Class Codes: H01L 2924/01022 : Titanium [Ti]
• CPC Class Codes: H01L 2924/01024 : Chromium [Cr]
• 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 2924/01031 : Gallium [Ga]
• 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 2924/01044 : 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 2924/0106 : Neodymium [Nd]
• 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 2924/0132 : Binary Alloys
• CPC Class Codes: H01L 2924/01322 : Eutectic Alloys, i.e. obtained by a liquid transforming into two solid phases
• CPC Class Codes: H01L 2924/01327 : Intermediate phases, i.e. intermetallics compounds
• 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 2924/15153 : the die mounting substrate comprising a recess for hosting the device
• CPC Class Codes: H01L 2924/1517 : Multilayer substrate
• CPC Class Codes: H01L 2924/15312 : being a pin array, e.g. PGA
• 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 2924/16152 : Cap comprising a cavity for hosting the device, e.g. U-shaped cap
• CPC Class Codes: H01L 2924/16195 : Flat cap [not enclosing an internal cavity]
• CPC Class Codes: H01L 2924/19041 : being a capacitor
• CPC Class Codes: H01L 2924/19043 : being a resistor
• CPC Class Codes: H01L 2924/19107 : off-chip wires
• CPC Class Codes: H01L 2924/2075 : larger or equal to 1 micron less than 10 microns
• CPC Class Codes: H01L 2924/20751 : larger or equal to 10 microns less than 20 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 2924/20756 : larger or equal to 60 microns less than 70 microns
• CPC Class Codes: H01L 2924/20757 : larger or equal to 70 microns less than 80 microns
• CPC Class Codes: H01L 2924/20758 : larger or equal to 80 microns less than 90 microns
• CPC Class Codes: H01L 2924/20759 : larger or equal to 90 microns less than 100 microns
• CPC Class Codes: H01L 2924/2076 : equal to or larger than 100 microns
• 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: H01L 2924/3512 : Cracking
• 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 3/308 : 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
• CPC Class Codes: Y10T 29/49144 : by metal fusion
• CPC Class Codes: Y10T 29/49147 : Assembling terminal to base
• CPC Class Codes: Y10T 29/49149 : by metal fusion bonding
• CPC Class Codes: Y10T 29/49151 : by deforming or shaping
• CPC Class Codes: Y10T 29/49155 : Manufacturing circuit on or in base
• CPC Class Codes: Y10T 29/49174 : Assembling terminal to elongated conductor
• CPC Class Codes: Y10T 29/49179 : by metal fusion bonding
• CPC Class Codes: Y10T 29/49204 : Contact or terminal manufacturing
• CPC Class Codes: Y10T 29/49222 : forming array of contacts or terminals
• CPC Class Codes: Y10T 29/49224 : with coating
• CPC Class Codes: Y10T 29/49609 : Spring making

Abstract

An interposer includes a substrate having opposing surfaces. Conductive terminals are disposed on both surfaces, and conductive terminals on one surface are electrically connected to conductive terminals on the opposing surface. Elongate, springable, conducive interconnect elements are fixed to conductive terminals on both surfaces.

Claims

1. An electronic interposer comprising:

a substrate having first and second opposed surfaces;

a first plurality of conductive contacts disposed away from said first surface;

a second plurality of conductive contacts disposed away from said second surface; and

interconnection means for resiliently electrically connecting through said substrate said first plurality of contacts with said second plurality of contacts,

wherein at least a portion of said interconnection means comprises;

flexible precursor means for defining a shape of said spring contact, and

overcoat means for enveloping at least a portion of said flexible precursor means,

said overcoat means comprising a material that is stronger than said flexible precursor means.

2. An electronic interposer comprising:

a substrate having first and second opposed surfaces;

a first plurality of conductive contacts disposed away from said first surface;

a second plurality of conductive contacts disposed away from said second surface; and

a plurality of conductive interconnect structures electrically connecting said first plurality of contacts with said second plurality of contacts, portions of said conductive interconnect structures passing through said substrate from said first surface to said second surface, at least a portion of each said conductive interconnect structure being resilient,

wherein said resilient portion of at least one of said conductive interconnect structures comprises;

an elongate precursor element comprising a flexible material, and

an overcoat material enveloping at least a portion of said elongate precursor element, said overcoat material being stronger than said flexible material.

3. An electronic interposer comprising:

a substrate having first and second opposed sides,

a first plurality of electrically conductive terminals on said first side,

a second plurality of electrically conductive terminals on said second side, ones of said first plurality of terminals being electrically connected to ones of said second plurality of terminals,

a first plurality of elongate, springable, conductive interconnect elements fixedly mounted to said first plurality of terminals, each of said first plurality of interconnect elements having a contact portion spaced from said substrate, and

a second plurality of conductive interconnect elements fixedly mounted to said second plurality of terminals,

wherein at least one of said first plurality of interconnect elements comprises;

an elongate precursor element comprising a flexible material; and

an overcoat material enveloping at least a portion of said elongate precursor element, said overcoat material being stronger than said flexible material.

4. The electronic interposer of claim 3, wherein said flexible material comprises a material selected from a group consisting of gold, aluminum, copper, silver, and platinum.

5. The electronic interposer of claim 3, wherein said overcoat material comprises a material selected from a group consisting of nickel, cobalt, iron, copper, gold, platinum, silver, rhodium and ruthenium.

6. The electronic interposer of claim 3, wherein said overcoat material is formed directly on said flexible material.

7. The electronic interposer of claim 3, wherein said at least one of said first plurality of interconnect elements further comprises a material disposed between said flexible material and said overcoat material.

8. The electronic interposer of claim 3, wherein at least one of said plurality of second interconnect elements comprises:

a second elongate precursor element comprising a second flexible material, and

a second overcoat enveloping at least a portion of said second elongate precursor element, said second overcoat material being stronger than said second flexible material.

9. The electronic interposer of claim 3, wherein said elongate precursor element includes first and second opposing ends, and at least said first end is secured to one of said first plurality of terminals.

10. The electronic interposer of claim 9, wherein said overcoat material covers at least a portion of said one of said first plurality of terminals.

11. The electronic interposer of claim 9, wherein said second end is also secured to said one of said first plurality of terminals.

12. The electronic interposer of claim 9, wherein only said first end is secured to said one of said first plurality of terminals.

13. The electronic interposer of claim 3, wherein said plurality of second electrically conductive terminals are elongate and springable, and each of said second plurality of interconnect elements has a contact portion spaced from said substrate.

14. An electronic interposer comprising:

a substrate having first and second opposed sides,

a first plurality of electrically conductive terminals on said first side,

a second plurality of electrically conductive terminals on said second side, ones of said first plurality of terminals being electrically connected to ones of said second plurality of terminals,

a first plurality of elongate, springable, conductive interconnect elements fixedly mounted to said first plurality of terminals, each of said first plurality of interconnect elements having a contact portion spaced from said substrate, and

a second plurality of conductive interconnect elements fixedly mounted to said second plurality of terminals,

wherein an outer surface of at least one of said first plurality of interconnect elements includes a plurality of local protrusions.

15. The electronic interposer of claim 14, wherein said local protrusions are caused by particulates within a material composing said interconnect element.

16. The electronic interposer of claim 14, wherein said local protrusions are caused by dendritic growth of a material composing said interconnect element.

17. The electronic interposer of claim 14, wherein said plurality of second electrically conductive terminals are elongate and springable, and each of said second plurality of interconnect elements has a contact portion spaced from said substrate.

18. An electronic interposer comprising:

substrate means for supporting a first plurality of electrically conductive terminals on a first side thereof and a second plurality of electrically conductive terminals on a second side thereof;

means for electrically connecting ones of said first plurality of electrically conductive terminals with ones of said second plurality of electrically conductive terminals;

a plurality of first spring contact means for providing springable, conductive interconnects from said first plurality of conductive terminals to points spaced from said first side of said substrate means; and

a plurality of second contact means for providing conductive interconnects from said second plurality of conductive terminals to points spaced from said second side of said substrate means,

wherein at least one of said first spring contact means comprises;

flexible precursor means for defining a shape of said spring contact; and

overcoat means for enveloping at least a portion of said flexible precursor means, said overcoat means comprising a material that is stronger than said flexible precursor means.

19. The electronic interposer of claim 18, wherein said plurality of second spring contact means further provide springable conductive interconnects from said second plurality of conductive terminals to points spaced from said second side of said substrate means.

20. A method of making an electronic interposer comprising:

providing a substrate having first and second opposed sides, a first plurality of electrically conductive terminals disposed on said first side, and a second plurality of electrically conductive terminals disposed on said second side, ones of said first plurality of terminals being electrically connected to ones of said second plurality of terminals;

fixing a first plurality of elongate, springable, conductive interconnect elements to ones of said first plurality of electrically conductive terminals, each of said first plurality of interconnect elements having a contact portion spaced from said substrate; and

fixing a second plurality of conductive interconnect elements to ones of said second plurality of electrically conductive terminals,

wherein said step of fixing a first plurality of interconnect elements comprises;

fixing an elongate precursor element comprising a flexible material to a conductive terminal; and

enveloping at least a portion of said elongate precursor element with a material that is stronger than said flexible material.

21. The method of claim 20, wherein said flexible material comprises a material selected from a group consisting of gold, aluminum, copper, silver, and platinum.

22. The method of claim 20, wherein said overcoat material comprises a material selected from a group consisting of nickel, cobalt, iron, copper, gold, platinum, silver, rhodium and ruthenium.

23. The method of claim 20, wherein said step of fixing a second plurality of interconnect elements comprises:

fixing an elongate precursor element comprising a flexible material to a conductive terminal; and

enveloping at least a portion of said elongate precursor element with a material that is stronger than said flexible material.

24. The method of claim 20, wherein said elongate precursor element includes first and second opposing ends, and said step of fixing said first plurality of interconnect elements further includes fixing said first end to said conductive terminal.

25. The method of claim 24 further including enveloping said conductive terminal with said material that is stronger than said flexible material.

26. The method of claim 24, wherein said step of fixing said first plurality of interconnect elements further includes also fixing said second end to said conductive terminal.

27. The method of claim 20, wherein said step of fixing a first plurality of interconnect elements further comprises:

prior to said step of enveloping at least a portion of said elongate precursor element with a material that is stronger than said flexible material, forming at least one material over at least a portion of said flexible material.

28. The method of claim 20, wherein said plurality of second electrically conductive terminals are elongate and springable, and each of said second plurality of interconnect elements has a contact portion spaced from said substrate.

29. A method of making an electronic interposer comprising:

providing a substrate having first and second opposed sides, a first plurality of electrically conductive terminals disposed on said first side, and a second plurality of electrically conductive terminals disposed on said second side, ones of said first plurality of terminals being electrically connected to ones of said second plurality of terminals;

fixing a first plurality of elongate, springable, conductive interconnect elements to ones of said first plurality of electrically conductive terminals, each of said first plurality of interconnect elements having a contact portion spaced from said substrate;

fixing a second plurality of conductive interconnect elements to ones of said second plurality of electrically conductive terminals; and

forming a plurality of local protrusions in an outer surface of at least one of said first plurality of interconnect elements.

30. The method of claim 29 wherein said plurality of second electrically conductive terminals are elongate and springable, and each of said second plurality of interconnect elements has a contact portion spaced from said substrate.