Solderable flexible adhesive interposer as for an electronic package, and method for making same

• US 6,717,819 B1
• Filed: 05/25/2000
• Issued: 04/06/2004
• Est. Priority Date: 06/01/1999
• Status: Expired due to Fees

• Current Assignee: Amerasia International Technology, Inc.
• Original Assignee: Amerasia International Technology, Inc.
• Inventors: Chung, Kevin Kwong-Tai
• Primary Examiner(s): Talbott, David L.
• Assistant Examiner(s): DINH, TUAN T
• Application Number:
  US09/578,583
• Time in Patent Office: 1,412 Days
• Field of Search: 361/760-762, 361/776-779, 361/803, 174/52.2, 174/260-264, 174/258, 174/254, 298/30--32, 298/52, 156/275.5, 156/275.7, 257/778, 257/789, 257/795
• US Class Current: 361/760
• CPC Class Codes: B32B 2425/00 Cards, e.g. identity cards, credit cards
• CPC Class Codes: B32B 2429/00 Carriers for sound or information
• CPC Class Codes: B32B 37/203 One or more of the layers being plastic
• CPC Class Codes: G06K 19/07743 External electrical contacts
• CPC Class Codes: G06K 19/07745 Mounting details of integrated circuit chips
• CPC Class Codes: G06K 19/07747 at least one of the integrated circuit chips being mounted as a module
• CPC Class Codes: H01L 2224/02379 Fan-out arrangement
• CPC Class Codes: H01L 2224/05001 Internal layers
• CPC Class Codes: H01L 2224/05023 the whole internal layer protruding from the surface
• CPC Class Codes: H01L 2224/05026 the internal layer being disposed in a recess of the surface
• CPC Class Codes: H01L 2224/05124 Aluminium [Al] as principal constituent
• CPC Class Codes: H01L 2224/05144 Gold [Au] as principal constituent
• CPC Class Codes: H01L 2224/05147 Copper [Cu] as principal constituent
• CPC Class Codes: H01L 2224/05155 Nickel [Ni] as principal constituent
• CPC Class Codes: H01L 2224/05548 Bonding area integrally formed with a redistribution layer on the semiconductor or solid-state body
• CPC Class Codes: H01L 2224/05639 Silver [Ag] 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 2224/05664 Palladium [Pd] as principal constituent
• CPC Class Codes: H01L 2224/05669 Platinum [Pt] as principal constituent
• CPC Class Codes: H01L 2224/0616 : Random array, i.e. array with no symmetry
• CPC Class Codes: H01L 2224/16225 : the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/16235 : the bump connector connecting to a via metallisation of the item
• CPC Class Codes: H01L 2224/16237 : the bump connector connecting to a bonding area disposed in a recess of the surface of the item
• CPC Class Codes: H01L 2224/32225 : the item being non-metallic, e.g. insulating substrate with or without metallisation
• 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 2224/48091 : Arched
• CPC Class Codes: H01L 2224/48227 : connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/73204 : the bump connector being embedded into the layer connector
• CPC Class Codes: H01L 2224/73253 : Bump and layer connectors
• CPC Class Codes: H01L 2224/73265 : Layer and wire connectors
• CPC Class Codes: H01L 2225/0651 : Wire or wire-like electrical connections from device to substrate
• CPC Class Codes: H01L 2225/06517 : Bump or bump-like direct electrical connections from device to substrate
• CPC Class Codes: H01L 2225/0652 : Bump or bump-like direct electrical connections from substrate 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 2225/06541 : Conductive via connections through the device, e.g. vertical interconnects, through silicon via [TSV]
• CPC Class Codes: H01L 2225/06572 : Auxiliary carrier between devices, the carrier having an electrical connection structure
• CPC Class Codes: H01L 2225/06579 : TAB carriers; beam leads
• CPC Class Codes: H01L 2225/06582 : Housing for the assembly, e.g. chip scale package [CSP]
• CPC Class Codes: H01L 2225/06586 : Housing with external bump or bump-like connectors
• CPC Class Codes: H01L 23/055 : the leads having a passage through the base H01L23/057 takes precedence
• CPC Class Codes: H01L 23/49838 : Geometry or layout
• CPC Class Codes: H01L 23/4985 : Flexible insulating substrates H01L23/49572 and H01L23/49855 take precedence
• CPC Class Codes: H01L 23/49855 : for flat-cards, e.g. credit cards cards per se G06K19/00
• CPC Class Codes: H01L 23/5387 : Flexible insulating substrates H01L23/5388 takes 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 24/73 : Means for bonding being of different types provided for in two or more of groups H01L24/10, H01L24/18, H01L24/26, H01L24/34, H01L24/42, H01L24/50, H01L24/63, H01L24/71
• CPC Class Codes: H01L 25/0657 : Stacked arrangements of devices
• 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 2924/00014 : 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 2924/01014 : Silicon [Si]
• CPC Class Codes: H01L 2924/01028 : Nickel [Ni]
• CPC Class Codes: H01L 2924/01046 : Palladium [Pd]
• CPC Class Codes: H01L 2924/0105 : Tin [Sn]
• CPC Class Codes: H01L 2924/01078 : Platinum [Pt]
• CPC Class Codes: H01L 2924/01079 : Gold [Au]
• CPC Class Codes: H01L 2924/01322 : Eutectic Alloys, i.e. obtained by a liquid transforming into two solid phases
• CPC Class Codes: H01L 2924/09701 : Low temperature co-fired ceramic [LTCC]
• CPC Class Codes: H01L 2924/12042 : LASER
• CPC Class Codes: H01L 2924/14 : Integrated circuits
• CPC Class Codes: H01L 2924/15173 : in a single layer of the multilayer substrate
• CPC Class Codes: H01L 2924/15174 : in different layers of the multilayer substrate
• CPC Class Codes: H01L 2924/15311 : being a ball array, e.g. BGA
• CPC Class Codes: H01L 2924/16152 : Cap comprising a cavity for hosting the device, e.g. U-shaped cap
• CPC Class Codes: H01L 2924/19041 : being a capacitor
• CPC Class Codes: H01Q 1/2225 : used in active tags, i.e. provided with its own power source or in passive tags, i.e. deriving power from RF signal
• CPC Class Codes: H01Q 1/36 : Structural form of radiating elements, e.g. cone, spiral, umbrella; Particular materials used therewithH01Q1/08, H01Q1/14 take precedence
• CPC Class Codes: H01Q 1/38 : formed by a conductive layer on an insulating support patch antennas H01Q9/0407; microstrip dipole antennas H01Q9/065; microstrip slot antennas H01Q13/106; transmission line microstrip antennas H01Q13/206; manufacturing reflecting surfaces using insulating material for supporting the reflecting surface H01Q15/142
• CPC Class Codes: H01Q 23/00 : Antennas with active circuits or circuit elements integrated within them or attached to them
• CPC Class Codes: H01Q 7/00 : Loop antennas with a substantially uniform current distribution around the loop and having a directional radiation pattern in a plane perpendicular to the plane of the loop
• CPC Class Codes: H01Q 7/005 : with variable reactance for tuning the antenna
• CPC Class Codes: H05K 1/0393 : Flexible materials H05K1/038 takes precedence; specific organic compositions are classified in H05K1/0313 and subgroups
• CPC Class Codes: H05K 1/113 : Via provided in pad; Pad over filled via
• CPC Class Codes: H05K 1/165 : incorporating printed inductors
• CPC Class Codes: H05K 2201/0355 : Metal foils
• CPC Class Codes: H05K 2201/0394 : Conductor crossing over a hole in the substrate or a gap between two separate substrate parts
• CPC Class Codes: H05K 2201/10674 : Flip chip
• CPC Class Codes: H05K 3/4069 : for via connections in organic insulating substrates
• CPC Class Codes: H05K 3/423 : characterised by electroplating method

Abstract

A solderable flexible adhesive interposer having solderable contacts includes low-modulus-of-elasticity (i.e. molecularly flexible) conductive adhesive vias to which contacts of an electronic device, such as a semiconductor chip or die or other component, are connected. The flexible adhesive interposer substrate includes a sheet or layer of a molecularly flexible dielectric adhesive having via holes therein through which the flexible conductive adhesive vias reside. A thin layer of solderable metal, preferably a plating of gold or nickel-gold, on at least one exposed surface of the flexible conductive adhesive vias provides the solderable contacts connecting electrically to the conductive vias. The electronic device may be covered by a lid or by an encapsulant attached to the flexible adhesive interposer substrate and/or the electronic device.

Claims

1. An electronic package having contacts adapted to be attached to a substrate, said electronic package comprising:

at least one electronic device, said electronic device having a plurality of contacts thereon;

a solderable flexible adhesive interposer including;

at least one layer of flexible dielectric adhesive having a modulus of elasticity less than about 35,000 kg/cm² (about 500,000 psi),

a plurality of conductive vias through said layer of flexible dielectric adhesive, said plurality of conductive vias being of a flexible electrically conductive adhesive having a modulus of elasticity less than about 35,000 kg/cm² (about 500,000 psi) and being in a pattern corresponding to a pattern of contacts of one of said electronic device and a substrate, and

a solderable electrically conductive metal formed on at least one exposed surface of said conductive vias and in electrical contact therewith,

wherein at least one end of the plurality of conductive vias includes contacts adapted to be attached to the substrate and means for connecting the contacts of said electronic device to said conductive vias.

2. The electronic package of claim 1 wherein said means for connecting includes connections of one of solder and electrically-conductive adhesive joining proximate corresponding ones of said conductive vias to the contacts of said electronic device.

3. The electronic package of claim 1 wherein said plurality of conductive vias are in a pattern corresponding to the pattern of contacts of said electronic device, said solderable flexible adhesive interposer further comprising patterned metal conductors on one surface of said layer of flexible dielectric adhesive fanning out from at least ones of said conductive vias to locations corresponding to the pattern of contacts of the substrate.

4. The electronic package of claim 1 wherein said plurality of conductive vias are in a pattern corresponding to the pattern of contacts of the substrate, said solderable flexible adhesive interposer further comprising patterned metal conductors on one surface of said layer of flexible dielectric adhesive fanning out from at least ones of said conductive vias to locations corresponding to the pattern of contacts of said electronic device.

5. The electronic package of claim 1 further comprising a protective enclosure surrounding said electronic device, wherein said protective enclosure is one of a cover attached at its edges to the periphery of said solderable flexible adhesive interposer and an encapsulant surrounding said electronic device and bonded to said solderable flexible adhesive interposer at least along the periphery thereof.

6. The electronic package of claim 1 wherein at least one of said flexible dielectric adhesive and said flexible conductive adhesive has a modulus of elasticity less than about 7,000 kg/cm² (about 100,000 psi).

7. The electronic package of claim 1 wherein at least one of said flexible dielectric adhesive and said flexible conductive adhesive has a modulus of elasticity less than about 1,400 kg/cm² (about 20,000 psi).

8. The electronic package of claim 1 wherein said solderable electrically conductive metal is selected from the group consisting of copper, nickel, tin, lead, indium, silver, gold, palladium, platinum, nickel-gold, nickel-palladium, platinum, combinations thereof, and alloys thereof.

9. The electronic package of claim 1 further comprising an underfill adhesive bonding said electronic device and said flexible dielectric adhesive interposer.

10. The electronic package of claim 1 wherein said flexible conductive adhesive is one of a thermosetting adhesive and a thermoplastic adhesive having a melt flow temperature that exceeds the melting temperature of solder.

11. The electronic package of claim 1 in combination with a substrate having a plurality of substrate contacts thereon in a pattern corresponding to at least ones of the conductive vias of said solderable flexible adhesive interposer, and second means for connecting the ones of the conductive vias of said solderable flexible adhesive interposer to corresponding contacts of said substrate.

12. The electronic package of claim 4 wherein said electronic device is attached to said solderable flexible adhesive interposer with its contacts distal therefrom, and wherein said means for connecting includes wires bonded between the contacts of said electronic device and ones of said conductive vias.

13. The electronic package of claim 5 wherein said protective enclosure includes a cover attached at its edges to the periphery of said solderable flexible adhesive interposer and attached by a flexible adhesive to a surface of said electronic device distal said solderable flexible adhesive interposer.

14. The electronic package of claim 9 wherein said underfill adhesive includes flexible dielectric adhesive having a modulus of elasticity less than about 35,000 kg/cm² (about 500,000 psi).

15. The electronic package of claim 11 wherein said second means for connecting includes connections of one of solder and electrically-conductive adhesive joining proximate corresponding ones of said conductive vias to the contacts of said substrate.

16. A solderable flexible adhesive interposer comprising:

at least one layer of flexible dielectric adhesive having a modulus of elasticity less than about 35,000 kg/cm² (about 500,000 psi),

a plurality of conductive vias through said layer of flexible dielectric adhesive, said plurality of conductive vias being of a flexible electrically conductive adhesive having a modulus of elasticity less than about 35,000 kg/cm² (about 500,000 psi) and being in a pattern adapted for connection to contacts of an electronic device or a substrate, and

a solderable electrically conductive metal formed on at least one exposed surface of said conductive vias and in electrical contact therewith,

wherein at least one end of the plurality of conductive vias includes contacts adapted to be soldered to the electronic device or the substrate.

17. The solderable flexible adhesive interposer of claim 16 wherein said plurality of conductive vias are in a pattern corresponding to a pattern of contacts of one of an electronic device and a substrate, said solderable flexible adhesive interposer further comprising patterned metal conductors on one surface of said layer of flexible dielectric adhesive fanning out from at least ones of said conductive vias to locations corresponding to the pattern of contacts of the other one of an electronic device and a substrate.

18. The solderable flexible adhesive interposer of claim 16 wherein at least one of said flexible dielectric adhesive and said flexible conductive adhesive has a modulus of elasticity less than about 7,000 kg/cm² (about 100,000 psi).

19. The solderable flexible adhesive interposer of claim 16 wherein at least one of said flexible dielectric adhesive and said flexible conductive adhesive has a modulus of elasticity less than about 1,400 kg/cm² (about 20,000 psi).

20. The solderable flexible adhesive interposer of claim 16 wherein said solderable electrically conductive metal is selected from the group consisting of copper, nickel, tin, lead, indium, silver, gold, palladium, platinum nickel-gold, nickel-palladium, platinum, combinations thereof, and alloys thereof.

21. The solderable flexible adhesive interposer of claim 16 wherein said flexible conductive adhesive is one of a thermosetting adhesive and a thermoplastic adhesive having a melt flow temperature that exceeds the melting temperature of solder.

22. The solderable flexible adhesive interposer of claim 16 in combination with at least one electronic device having a plurality of contacts thereon connected by one of solder and electrically conductive adhesive to at least certain ones of said conductive vias of said solderable flexible adhesive interposer.

23. A solderable flexible adhesive interposer comprising:

a plurality of layers of flexible dielectric adhesive having a modulus of elasticity less than about 35,000 kg/cm² (about 500,000 psi);

a plurality of conductive vias through each of said layers of flexible dielectric adhesive, said plurality of conductive vias being of a flexible electrically conductive adhesive having a modulus of elasticity less than about 35,000 kg/cm² (about 500,000 psi), said conductive vias in an exposed one of said plurality of flexible dielectric adhesive layers being in a pattern adapted for connection to contacts of an electronic device or a substrate;

a solderable electrically conductive metal formed on an exposed surface of said conductive vias of the exposed one of said flexible dielectric adhesive layers and in electrical contact therewith, wherein at least one end of the plurality of conductive vias includes contacts adapted to be soldered to the electronic device or the substrate;

said plurality of conductive vias in each said layer of flexible dielectric adhesive being in a pattern corresponding at least in part to a pattern of said plurality of conductive vias of the adjacent layers of said flexible dielectric adhesive; and

a conductor residing between at least two of said adjacent layers of flexible dielectric adhesive, wherein said conductor is patterned and is in electrical contact with ones of said conductive vias of each of the at least two of said layers of flexible dielectric adhesive.

24. The solderable flexible adhesive interposer of claim 23 wherein said conductive vias of the exposed flexible dielectric adhesive layer are in a pattern corresponding to a pattern of contacts of one of an electronic device and a substrate, said solderable flexible adhesive interposer further comprising patterned metal conductors on a surface of another of said layers of flexible dielectric adhesive fanning out from at least ones of said conductive vias to locations corresponding to the pattern of contacts of the other one of an electronic device and a substrate.

25. The solderable flexible adhesive interposer of claim 23 wherein at least one of said flexible dielectric adhesive and said flexible conductive adhesive has a modulus of elasticity less than about 7,000 kg/cm² (about 100,000 psi).

26. The solderable flexible adhesive interposer of claim 23 wherein at least one of said flexible dielectric adhesive and said flexible conductive adhesive has a modulus of elasticity less than about 1,400 kg/cm² (about 20,000 psi).

27. The solderable flexible adhesive interposer of claim 23 wherein said solderable electrically conductive metal is selected from the group consisting of copper, nickel, tin, lead, indium, silver, gold, palladium, platinum, nickel-gold, nickel-palladium, platinum, combinations thereof, and alloys thereof.

28. The solderable flexible adhesive interposer of claim 23 wherein said flexible conductive adhesive is one of a thermosetting adhesive and a thermoplastic adhesive having a melt flow temperature that exceeds the melting temperature of solder.

29. The solderable flexible adhesive interposer of claim 23 in combination with at least one electronic device having a plurality of contacts thereon connected by one of solder and electrically conductive adhesive to at least certain ones of said conductive vias of a first of said plurality of layers of flexible dielectric adhesive.

30. A panel of a plurality of electronic devices having a pattern of contacts thereon and solderable flexible adhesive connections formed on the contacts comprising:

a layer of an oxidation-resistant metal on the contacts of the electronic devices of said panel;

a plurality of electrically conductive bumps formed of a flexible electrically conductive adhesive having a modulus of elasticity less than about 35,000 kg/cm² (about 500,000 psi), wherein said plurality of bumps is deposited on the oxidation resistant layer in the pattern of contacts of the electronic device; and

a solderable electrically conductive metal layer formed on an exposed surface of said electrically conductive bumps distal the contacts of the electronic devices and in electrical contact therewith,

wherein said panel includes one of a semiconductor wafer having a plurality of semiconductor devices formed therein and a panel of electrical substrates having a plurality of electrical substrates formed therein.

31. The panel of a plurality of electronic devices of claim 30 wherein said flexible conductive adhesive has a modulus of elasticity less than about 7,000 kg/cm² (about 100,000 psi).

32. The panel of a plurality of electronic devices of claim 30 wherein said flexible conductive adhesive has a modulus of elasticity less than about 1,400 kg/cm² (about 20,000 psi).

33. The panel of a plurality of electronic devices of claim 30 wherein said flexible conductive adhesive is one of a thermosetting adhesive and a thermoplastic adhesive having a melt flow temperature that exceeds the melting temperature of solder.

34. The panel of a plurality of electronic devices of claim 30 wherein said solderable electrically conductive metal is selected from the group consisting of copper, nickel, tin, lead, indium, silver, gold, palladium, platinum, nickel-gold, nickel-palladium, platinum, combinations thereof, and alloys thereof.

35. An electronic device having solderable flexible adhesive connections formed on the contacts thereof excised from the panel of a plurality of electronic devices of claim 30.