Inductive heating of microelectronic components

• US 20030115749A1
• Filed: 12/21/2001
• Published: 06/26/2003
• Est. Priority Date: 12/21/2001
• Status: Active Grant

• Current Assignee: FormFactor Incorporated
• Original Assignee: FormFactor Incorporated
• Inventors: Chen, Jimmy Kuo
• Granted Patent: US 7,168,160 B2
• Time in Patent Office: Days
• US Class Current: 29/848
• CPC Class Codes: H01L 2224/05568 the whole external layer protruding from the surface
• CPC Class Codes: H01L 2224/05573 Single external layer
• CPC Class Codes: H01L 2224/13099 Material
• CPC Class Codes: H01L 2224/13144 Gold [Au] as principal constituent
• CPC Class Codes: H01L 2224/13655 Nickel [Ni] as principal constituent
• CPC Class Codes: H01L 2224/45144 Gold (Au) as principal constituent
• CPC Class Codes: H01L 2224/81801 Soldering or alloying
• 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 24/81 using a bump 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 2924/00014 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 2924/01027 Cobalt [Co]
• 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 2924/01047 Silver [Ag]
• 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 2924/014 : Solder alloys
• CPC Class Codes: H01L 2924/14 : Integrated circuits
• CPC Class Codes: H01L 2924/15787 : Ceramics, e.g. crystalline carbides, nitrides or oxides
• CPC Class Codes: H01L 2924/30105 : Capacitance
• CPC Class Codes: H01L 2924/3011 : Impedance
• CPC Class Codes: H05K 3/22 : Secondary treatment of printed circuits H05K3/1283 takes precedence; embedding circuits in grooves by pressure H05K3/107
• CPC Class Codes: H05K 3/4092 : Integral conductive tabs, i.e. conductive parts partly detached from the substrate
• CPC Class Codes: Y10T 29/49142 : including metal fusion
• CPC Class Codes: Y10T 29/49144 : by metal fusion
• CPC Class Codes: Y10T 29/49149 : by metal fusion bonding
• CPC Class Codes: Y10T 29/49158 : with molding of insulated base
• CPC Class Codes: Y10T 29/49179 : by metal fusion bonding
• CPC Class Codes: Y10T 29/49204 : Contact or terminal manufacturing
• CPC Class Codes: Y10T 29/49213 : Metal
• CPC Class Codes: Y10T 29/49222 : forming array of contacts or terminals

Abstract

A method for heat-treating a plurality of microelectronic structures attached to a non-metallic substrate is disclosed. Each of the plurality of microelectronic structures is comprised of a metallic material, and ones of the plurality of metallic microelectronic structures are insulated from other ones of the plurality of microelectronic structures. An application of the method is for heat-treatment of resilient microstructures. The method comprises the steps of: (a) placing the non-metallic substrate and the plurality of microelectronic structures in an oscillating electromagnetic field, whereby the plurality of microelectronic structures are heated by the oscillating electromagnetic field and the non-metallic substrate is essentially not heated by the oscillating electromagnetic field; (b) maintaining the non-metallic substrate and the plurality of microelectronic structures in the oscillating electromagnetic field until each of the plurality of microelectronic structures obtains a defined heat-treatment temperature substantially greater than an ambient temperature; (c) removing the non-metallic substrate and the plurality of microelectronic structures from the oscillating electromagnetic field; and (d) cooling the plurality of microelectronic structures to the ambient temperature.

Claims

1. A method for heating a plurality of microelectronic structures attached to a non-metallic substrate, wherein each of the plurality of microelectronic structures is comprised of a metallic material, and ones of the plurality of metallic microelectronic structures are insulated from other ones of the plurality of microelectronic structures, the method comprising the steps of:

placing the non-metallic substrate and the plurality of microelectronic structures in an oscillating electromagnetic field, whereby the plurality of microelectronic structures are heated by the oscillating electromagnetic field and the non-metallic substrate is essentially not heated by the oscillating electromagnetic field;

maintaining the non-metallic substrate and the plurality of microelectronic structures in the oscillating electromagnetic field until each of the plurality of microelectronic structures obtains a defined heat-treatment temperature substantially greater than an ambient temperature;

removing the non-metallic substrate and the plurality of microelectronic structures from the oscillating electromagnetic field; and

cooling the plurality of microelectronic structures to the ambient temperature.

2. The method according to claim 1, wherein the placing step further comprises placing the plurality of microelectronic structures in the oscillating electromagnetic field, wherein the plurality of microelectronic structures are comprised of a ferromagnetic material.

3. The method according to claim 2, wherein the placing step further comprises placing the plurality of microelectronic structures in the oscillating electromagnetic field, wherein ferromagnetic material is a nickel-cobalt alloy.

4. The method according to claim 2, further comprising tuning the oscillating electromagnetic field to selectively heat the ferromagnetic material.

5. The method according to claim 1, wherein the maintaining step further comprises obtaining the heat-treatment temperature greater than 800°

C.

6. The method according to claim 1, wherein the maintaining step further comprises obtaining the heat-treatment temperature greater than 1300°

C.

7. The method according to claim 1, further comprising generating the oscillating electromagnetic field between a pair of parallel plates.

8. The method according to claim 1, further comprising generating the oscillating electromagnetic field between arms of a hairpin coil.

9. The method according to claim 1, further comprising generating the oscillating electromagnetic field using a coil comprised of a copper tube formed into a coil shape.

10. The method according to claim 1, further comprising tuning the frequency of the oscillating electromagnetic field to a resonant frequency of a field generator circuit.

11. The method according to claim 1, further comprising tuning the frequency of the oscillating electromagnetic field to between about 10-15 MHz.

12. The method according to claim 1, further comprising measuring a temperature of the plurality of microelectronic structures by applying a heat-indicating paint to the plurality of microelectronic structures prior to the maintaining step.

13. The method according to claim 1, wherein ones of the plurality of microelectronic structures comprise separate components temporarily joined by solder paste prior to the maintaining step, and the maintaining step further comprising obtaining a heat-treatment temperature greater than an activation temperature of the solder paste, whereby the separate components are soldered together.