Method and materials for printing particle-enhanced electrical contacts

• US 20040087128A1
• Filed: 04/24/2003
• Published: 05/06/2004
• Est. Priority Date: 10/24/2000
• Status: Abandoned Application

• Current Assignee: Bio Lab Naturals, Inc. (Limitless X Holdings, Inc.)
• Original Assignee: Bio Lab Naturals, Inc. (Limitless X Holdings, Inc.)
• Inventors: Zou, Bin, Neuhaus, Herbert J
• Application Number:
  US10/415,193
• Publication Number:
  US 20040087128A1
• Time in Patent Office: Days
• US Class Current: 438/610
• CPC Class Codes: H01B 1/16 the conductive material comprising metals or alloys
• CPC Class Codes: H01B 1/22 the conductive material comprising metals or alloys
• 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 2224/11505 Sintering
• CPC Class Codes: H01L 2224/13099 Material
• CPC Class Codes: H01L 2224/29099 Material
• CPC Class Codes: H01L 2224/29101 the principal constituent melting at a temperature of less than 400°C
• CPC Class Codes: H01L 2224/2919 with a principal constituent of the material being a polymer, e.g. polyester, phenolic based polymer, epoxy
• CPC Class Codes: H01L 2224/29199 Material of the matrix
• CPC Class Codes: H01L 2224/2929 with a principal constituent of the material being a polymer, e.g. polyester, phenolic based polymer, epoxy
• CPC Class Codes: H01L 2224/29299 Base material
• CPC Class Codes: H01L 2224/293 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 2224/29305 Gallium [Ga] as principal constituent
• CPC Class Codes: H01L 2224/29309 Indium [In] as principal constituent
• CPC Class Codes: H01L 2224/29311 Tin [Sn] as principal constituent
• CPC Class Codes: H01L 2224/29313 Bismuth [Bi] as principal constituent
• CPC Class Codes: H01L 2224/29323 Magnesium [Mg] as principal constituent
• CPC Class Codes: H01L 2224/29324 Aluminium [Al] as principal constituent
• CPC Class Codes: H01L 2224/29339 Silver [Ag] as principal constituent
• CPC Class Codes: H01L 2224/29344 Gold [Au] as principal constituent
• CPC Class Codes: H01L 2224/29347 : Copper [Cu] as principal constituent
• CPC Class Codes: H01L 2224/29355 : Nickel [Ni] as principal constituent
• CPC Class Codes: H01L 2224/29364 : Palladium [Pd] as principal constituent
• CPC Class Codes: H01L 2224/29369 : Platinum [Pt] as principal constituent
• CPC Class Codes: H01L 2224/29411 : Tin [Sn] as principal constituent
• CPC Class Codes: H01L 2224/29444 : Gold [Au] as principal constituent
• CPC Class Codes: H01L 2224/29455 : Nickel [Ni] as principal constituent
• CPC Class Codes: H01L 2224/29464 : Palladium [Pd] as principal constituent
• CPC Class Codes: H01L 2224/29469 : Platinum [Pt] as principal constituent
• CPC Class Codes: H01L 2224/8319 : Arrangement of the layer connectors prior to mounting
• CPC Class Codes: H01L 2224/838 : Bonding techniques
• CPC Class Codes: H01L 23/49883 : the conductive materials containing organic materials or pastes, e.g. for thick films for printed circuits H05K1/092
• 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 24/29 : of an individual layer connector
• CPC Class Codes: H01L 24/83 : using a layer connector
• 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 2924/0001 : Technical content checked by a classifier
• 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 2924/01004 : Beryllium [Be]
• 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 2924/01013 : Aluminum [Al]
• CPC Class Codes: H01L 2924/01019 : Potassium [K]
• CPC Class Codes: H01L 2924/0102 : Calcium [Ca]
• 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 2924/01032 : Germanium [Ge]
• CPC Class Codes: H01L 2924/01033 : Arsenic [As]
• CPC Class Codes: H01L 2924/01037 : Rubidium [Rb]
• CPC Class Codes: H01L 2924/01038 : Strontium [Sr]
• CPC Class Codes: H01L 2924/01039 : Yttrium [Y]
• 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 2924/01055 : Cesium [Cs]
• CPC Class Codes: H01L 2924/01056 : Barium [Ba]
• 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 2924/01327 : Intermediate phases, i.e. intermetallics compounds
• CPC Class Codes: H01L 2924/014 : Solder alloys
• CPC Class Codes: H01L 2924/0665 : Epoxy resin
• CPC Class Codes: H01L 2924/0781 : being an ohmic electrical conductor
• CPC Class Codes: H01L 2924/14 : Integrated circuits
• CPC Class Codes: H01L 2924/15747 : Copper [Cu] as principal constituent
• CPC Class Codes: H05K 1/095 : for polymer thick films, i.e. having a permanent organic polymeric binder
• CPC Class Codes: H05K 2201/023 : Hard particles, i.e. particles in conductive adhesive at least partly penetrating an electrode
• CPC Class Codes: H05K 2201/035 : Paste overlayer, i.e. conductive paste or solder paste over conductive layer
• CPC Class Codes: H05K 2201/0367 : Metallic bump or raised conductor not used as solder bump
• CPC Class Codes: H05K 3/245 : Reinforcing conductive patterns made by printing techniques or by other techniques for applying conductive pastes, inks or powders; Reinforcing other conductive patterns by such techniques
• CPC Class Codes: H05K 3/247 : Finish coating of conductors by using conductive pastes, inks or powders
• CPC Class Codes: H05K 3/325 : by abutting or pinching, i.e. without alloying process; mechanical auxiliary parts therefor adaptations of leads inserted in holes for press-fit connections H05K3/308
• CPC Class Codes: H05K 3/4007 : Surface contacts, e.g. bumps H05K3/4092 takes precedence; deposition of finish layers on pads H05K3/24; forming solder bumps H05K3/3457

Abstract

The disclosed invention relates to materials and processes for creating particle-enhanced bumps on electrical contact surfaces through stencil or screen printing processes. The materials are mixtures of conductive ink, conductive paste, or conductive adhesive and conductive hard particles (104). The process involves depositing the mixture (108) onto electrical contact surfaces by stencil printing, screen printing, or other dispensing techniques (110). In another embodiment, the ink, paste, or adhesive is first stenciled or screen printed and the particles are then applied on top of the ink, paste, or adhesive deposit. Once cured (114), the deposition provides a hard, electrical contact bump on the contact surface with a rough, conductive, sandpaper-like surface that can be easily connected to an opposing contact surface without any further surface preparation of either surface.

Claims

1. A composition for creating an electrically conductive contact on an electrically conductive surface, the composition comprising:

a viscous compound capable of adhering to the electrically conductive surface,

wherein the viscous compound comprises a precursor to an electrically conductive solid formed upon cure of the viscous compound; and

a plurality of electrically conductive hard particles,

wherein at least a portion of the plurality of conductive hard particles form a rough, conductive, sandpaper-like surface to the electrically conductive solid, and

wherein the plurality of electrically conductive hard particles has a hardness at least as great as that of an opposing electrically conductive surface to be joined in electrical and mechanical connection to the electrically conductive surface.

2. The composition as described in claim 1, wherein the plurality of electrically conductive hard particles is a plurality of metal particles comprising at least one of the following:

copper, aluminum, nickel, tin, bismuth, silver, gold, platinum, palladium, lithium, beryllium, boron, sodium, magnesium, potassium, calcium, gallium, germanium, rubidium, strontium, indium, antimony, cesium, and barium, and alloys and intermetallics of these metals.

3. The composition as described in claim 1, wherein the plurality of electrically conductive hard particles comprises a plurality of non-electrically-conductive particle cores surrounded by a metal layer.

4. The composition as described in claim 3, wherein the plurality of non-electrically-conductive particle cores comprises at least one of the following:

diamond, garnet, ceramic, oxides, silicides, silicates, carbides, carbonates, borides, boron fibers, and nitrides.

5. The composition as described in claim 3, wherein the metal layer comprises at least one of the following:

copper, aluminum, nickel, tin, bismuth, silver, gold, platinum, palladium, lithium, beryllium, boron, sodium, magnesium, potassium, calcium, gallium, germanium, rubidium, strontium, indium, antimony, cesium, and barium, and alloys and intermetallics of these metals.

6. The composition as described in claim 3, wherein the metal layer comprises a nickel layer and wherein the plurality of non-electrically-conductive particle cores comprises diamond.

7. The composition as described in claim 1, wherein the viscous compound comprises an electrically conductive ink.

8. The composition as described in claim 1, wherein the viscous compound comprises an electrically conductive paste.

9. The composition as described in claim 1, wherein the viscous compound comprises an electrically conductive adhesive.

10. The composition as described in claim 1, wherein the electrically conductive surface comprises a contact pad of an integrated circuit chip.

11. The composition as described in claim 1, wherein the electrically conductive surface comprises a plurality of discrete electrically conductive surfaces.

12. The composition as described in claim 11, wherein the plurality of discrete electrically conductive surfaces are electrically insulated from each other.

13. The composition as described in claim 11, wherein the plurality of discrete electrically conductive surfaces comprises an area array contact configuration of an integrated circuit chip.

14. The composition as described in claim 11, wherein the plurality of discrete electrically conductive surfaces comprises a plurality of contact surfaces of integrated circuit devices on a semiconductor wafer.

15. A method for creating an electrically conductive contact bump on an electrically conductive surface of an electrical component, the method comprising:

placing a stencil on the electrical component,

wherein the stencil comprises a pattern of an aperture through which the electrically conductive surface is exposed;

mixing a viscous compound with a plurality of electrically conductive hard particles,

wherein the viscous compound comprises a precursor to an electrically conductive solid formed upon cure of the viscous compound,

wherein the viscous compound is capable of adhering to the electrically conductive surface, and

wherein each of the plurality of electrically conductive hard particles has a hardness at least as great as that of an opposing electrically conductive surface to be joined in electrical and mechanical connection to the electrically conductive surface;

applying the viscous compound and electrically conductive hard particle mixture to the electrically conductive surface through the aperture in the stencil;

removing the stencil from the electrical component; and

curing the viscous compound and electrically conductive hard particle mixture applied to the electrically conductive surface to form the electrically conductive solid,

wherein at least a portion of the plurality of conductive hard particles form a rough, conductive, sandpaper-like surface to the electrically conductive solid.

19. The method as described in claim 15, 16, 17, or 18, wherein the plurality of electrically conductive hard particles is a plurality of metal particles comprising at least one of the following:

copper, aluminum, nickel, tin, bismuth, silver, gold, platinum, palladium, lithium, beryllium, boron, sodium, magnesium, potassium, calcium, gallium, germanium, rubidium, strontium, indium, antimony, cesium, and barium, and alloys and intermetallics of these metals.

20. The method as described in claim 15, 16, 17, or 18, wherein the plurality of electrically conductive hard particles comprises a plurality of non-electrically-conductive particle cores surrounded by a metal layer.

21. The method as described in claim 20, wherein the plurality of non-electrically-conductive particle cores comprises of at least one of the following:

diamond, garnet, ceramic, oxides, suicides, silicates, carbides, carbonates, borides, boron fibers, and nitrides.

22. The method as described in claim 20, wherein the metal layer comprises at least one of the following:

copper, aluminum, nickel, tin, bismuth, silver, gold, platinum, palladium, lithium, beryllium, boron, sodium, magnesium, potassium, calcium, gallium, germanium, rubidium, strontium, indium, antimony, cesium, and barium, and alloys and intermetallics of these metals.

23. The method as described in claim 20, wherein the metal layer comprises a nickel layer and wherein the plurality of non-electrically-conductive particle cores comprises diamond.

24. The method as described in claim 15, 16, 17, or 18, wherein the viscous compound comprises an electrically conductive ink.

25. The method as described in claim 15, 16, 17, or 18, wherein the viscous compound comprises an electrically conductive paste.

26. The method as described in claim 15, 16, 17, or 18, wherein the viscous compound comprises an electrically conductive adhesive.

27. The method as described in claim 15, 16, 17, or 18, wherein the electrically conductive surface comprises a contact pad of an integrated circuit chip.

28. The method as described in claim 15, 16, 17, or 18, wherein the electrically conductive surface comprises a plurality of discrete electrically conductive surfaces.

29. The method as described in claim 28, wherein the plurality of discrete electrically conductive surfaces are electrically insulated from each other.

30. The method as described in claim 28, wherein the plurality of discrete electrically conductive surfaces comprises an area array contact configuration of an integrated circuit chip.

31. The method as described in claim 28, wherein the plurality of discrete electrically conductive surfaces comprises a plurality of contact surfaces of integrated circuit devices on a semiconductor wafer.

16. A method for creating an electrically conductive contact bump on an electrically conductive surface of an electrical component, the method comprising:

placing a stencil on the electrical component,

wherein the stencil comprises a pattern of an aperture through which the electrically conductive surface is exposed;

applying a viscous compound to the electrically conductive surface through the aperture in the stencil,

wherein the viscous compound comprises a precursor to an electrically conductive solid formed upon cure of the viscous compound, and

wherein the viscous compound is capable of adhering to the electrically conductive surface;

removing the stencil from the electrical component;

depositing a plurality of electrically conductive hard particles over the viscous compound applied to the electrically conductive surface,

wherein each of the plurality of electrically conductive hard particles has a hardness at least as great as that of an opposing electrically conductive surface to be joined in electrical and mechanical connection to the electrically conductive surface; and

curing the viscous compound to form the electrically conductive solid,

wherein at least a portion of the plurality of conductive hard particles form a rough, conductive, sandpaper-like surface to the electrically conductive solid.

17. A method for creating an electrically conductive contact bump on an electrically conductive surface of an electrical component, the method comprising:

placing a screen on the electrical component

wherein the screen comprises a pattern of an exposed area and a non-exposed area,

wherein the exposed area is impervious to printable viscous compounds and particles,

wherein the non-exposed area comprises a grid defining apertures through which printable viscous compounds and particles of appropriate size may pass, and

wherein the non-exposed area is aligned with the electrically conductive surface;

mixing a viscous compound with a plurality of electrically conductive hard particles,

wherein the viscous compound comprises a precursor to an electrically conductive solid formed upon cure of the viscous compound,

wherein the viscous compound is capable of adhering to the electrically conductive surface,

wherein each of the plurality of electrically conductive hard particles has a hardness at least as great as that of an opposing electrically conductive surface to be joined in electrical and mechanical connection to the electrically conductive surface, and

wherein each of the plurality of electrically conductive hard particles is sized to pass through the grid apertures in the screen;

applying the viscous compound and electrically conductive hard particle mixture to the electrically conductive surface by pressing the mixture through the grid apertures in the non-exposed area of the screen;

removing the screen from the electrical component; and

curing the viscous compound and electrically conductive hard particle mixture applied to the electrically conductive surface to form the electrically conductive solid,

wherein at least a portion of the plurality of conductive hard particles form a rough, conductive, sandpaper-like surface to the electrically conductive solid.

18. A method for creating an electrically conductive contact bump on an electrically conductive surface of an electrical component, the method comprising:

placing a screen on the electrical component

wherein the screen comprises a pattern of an exposed area and a non-exposed area,

wherein the exposed area is impervious to printable viscous compounds,

wherein the non-exposed area comprises a grid defining apertures through which printable viscous compounds may pass, and

wherein the non-exposed area is aligned with the electrically conductive surface;

applying a viscous compound to the electrically conductive surface by pressing the viscous compound through the grid apertures in the non-exposed area of the screen,

wherein the viscous compound comprises a precursor to an electrically conductive solid formed upon cure of the viscous compound, and

wherein the viscous compound is capable of adhering to the electrically conductive surface;

removing the screen from the electrical component;

depositing a plurality of electrically conductive hard particles over the viscous compound applied to the electrically conductive surface,

wherein each of the plurality of electrically conductive hard particles has a hardness at least as great as that of an opposing electrically conductive surface to be joined in electrical and mechanical connection to the electrically conductive surface; and

curing the viscous compound to form the electrically conductive solid,

wherein at least a portion of the plurality of conductive hard particles form a rough, conductive, sandpaper-like surface to the electrically conductive solid.