Tools and methods for forming conductive bumps on microelectronic elements

• US 20060183270A1
• Filed: 02/10/2006
• Published: 08/17/2006
• Est. Priority Date: 02/14/2005
• Status: Abandoned Application

• Current Assignee: Tessera, Inc. (Adeia, Inc.)
• Original Assignee: Tessera, Inc. (Adeia, Inc.)
• Inventors: Humpston, Giles
• Application Number:
  US11/351,591
• Publication Number:
  US 20060183270A1
• Time in Patent Office: Days
• US Class Current: 438/106
• CPC Class Codes: B23K 2101/40 Semiconductor devices
• CPC Class Codes: B23K 3/0623 for shaped solder piece feeding, e.g. preforms, bumps, balls, pellets, droplets
• CPC Class Codes: H01L 21/6835 using temporarily an auxiliary support
• CPC Class Codes: H01L 2224/0554 External layer
• CPC Class Codes: H01L 2224/0555 Shape
• CPC Class Codes: H01L 2224/0556 Disposition
• 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 2224/05599 Material
• CPC Class Codes: H01L 2224/05624 Aluminium [Al] as principal constituent
• CPC Class Codes: H01L 2224/11003 for holding or transferring the bump preform
• CPC Class Codes: H01L 2224/11334 using preformed bumps
• CPC Class Codes: H01L 2224/1147 using a lift-off mask
• CPC Class Codes: H01L 2224/13099 Material
• CPC Class Codes: H01L 2224/132 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 2224/16 of an individual bump connector
• 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 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 2924/01006 : Carbon [C]
• CPC Class Codes: H01L 2924/01012 : Magnesium [Mg]
• CPC Class Codes: H01L 2924/01013 : Aluminum [Al]
• CPC Class Codes: H01L 2924/01015 : Phosphorus [P]
• CPC Class Codes: H01L 2924/01018 : Argon [Ar]
• CPC Class Codes: H01L 2924/01019 : Potassium [K]
• 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 2924/01029 : Copper [Cu]
• CPC Class Codes: H01L 2924/0103 : Zinc [Zn]
• CPC Class Codes: H01L 2924/01033 : Arsenic [As]
• CPC Class Codes: H01L 2924/01047 : Silver [Ag]
• CPC Class Codes: H01L 2924/01049 : Indium [In]
• CPC Class Codes: H01L 2924/01057 : Lanthanum [La]
• CPC Class Codes: H01L 2924/01061 : Promethium [Pm]
• 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 2924/01092 : Uranium [U]
• CPC Class Codes: H01L 2924/01105 : Rare earth metals
• 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 2924/09701 : Low temperature co-fired ceramic [LTCC]
• CPC Class Codes: H01L 2924/12044 : OLED
• CPC Class Codes: H01L 2924/16235 : Connecting to a semiconductor or solid-state bodies, i.e. cap-to-chip

Abstract

A method of making a microelectronic assembly includes providing a microelectronic element having a front face and contact pads accessible at the front face, providing a dispensing tool containing a molten metal and having a discharge port for dispensing the molten metal, and aligning the discharge port of the dispensing tool with one of the contact pads of the microelectronic element. A mass of the molten metal is dispensed through the discharge port and onto the one of the contact pads of the microelectronic element; and ultrasonic waves are applied to the mass of molten metal during the dispensing step for facilitating wetting of the mass of molten metal with the one of the contact pads of the microelectronic element.

Claims

1. A method of making a microelectronic assembly comprising:

providing a microelectronic element having a front face and contact pads accessible at the front face;

dispensing a mass of molten metal onto one of the contact pads of said microelectronic element;

applying ultrasonic waves to the mass of molten metal during the dispensing step for facilitating wetting of the mass of molten metal with the one of the contact pads of said microelectronic element.

2. The method as claimed in claim 1, further comprising modifying the frequency of the ultrasonic waves applied to the molten metal.

3. The method as claimed in claim 1, wherein the dispensing step comprises:

providing a dispensing tool containing a molten metal, said tool having a discharge port for dispensing the molten metal; and

aligning the discharge port of said dispensing tool with the one of the contact pads of said microelectronic element and dispensing the mass of the molten metal through the discharge port and onto the one of the contact pads of said microelectronic element.

4. The method as claimed in claim 1, further comprising repeating the dispensing step for dispensing a mass of molten metal atop a plurality of the contact pads of said microelectronic element.

5. The method as claimed in claim 3, wherein said dispensing tool comprises:

a chamber for holding the molten metal, the chamber being in communication with the discharge port;

an ultrasonic transducer coupled with said chamber for producing the ultrasonic waves.

6. The method as claimed in claim 3, further comprising:

providing a planar element over the front face of said microelectronic element, said planar element having at least one opening extending therethrough;

aligning the at least one opening in said planar element with the one of the contacts of said microelectronic element;

aligning the discharge port of said dispensing tool with the at least one opening in said planar element.

7. The method as claimed in claim 6, wherein said planar element is connected with said microelectronic element.

8. The method as claimed in claim 6, wherein said planar element is connected with said dispensing tool.

9. The method as claimed in claim 6, wherein said microelectronic element is selected from the group consisting of semiconductor wafers, semiconductor chips and circuitized substrates.

10. The method as claimed in claim 1, wherein said ultrasonic pressure waves have a frequency of about 20 KHz-100 MHz.

11. The method as claimed in claim 5, wherein said ultrasonic transducer generates ultrasonic waves having a frequency of about 20 KHz-100 MHz.

12. The method as claimed in claim 3, further comprising:

connecting an ultrasonic transducer with said dispensing tool; and

operating said ultrasonic transducer during the dispensing step.

13. The method as claimed in claim 12, wherein said ultrasonic transducer is coupled with the discharge port of said dispensing tool.

14. The method as claimed in claim 3, wherein said dispensing tool has a C4NP-like configuration and at least one ultrasonic transducer coupled with said dispensing tool.

15. The method as claimed in claim 14, wherein said at least one ultrasonic transducer includes a controller for modifying the frequency of the ultrasonic waves generated by said at least one ultrasonic transducer.

16. The method as claimed in claim 1, wherein the contact pads of said microelectronic element comprise aluminum.

17. The method as claimed in claim 17, wherein the contacts of said microelectronic element further comprise a low melting point metal applied atop the aluminum pads.

18. The method as claimed in claim 17, wherein the low melting point metal is a fusible alloy.

19. The method as claimed in claim 18, wherein the fusible alloy is a pure metal or an alloy comprising indium, tin, lead, cadium or zinc.

20. A method of making a microelectronic assembly comprising:

providing a microelectronic element having a front face and contact pads accessible at the front face;

providing a dispensing tool containing a molten metal and having a discharge port for dispensing the molten metal;

aligning the discharge port of said dispensing tool with one of the contact pads of said microelectronic element;

dispensing a mass of the molten metal through the discharge port and onto the one of the contact pads of said microelectronic element; and

applying ultrasonic waves to the mass of molten metal during the dispensing step for facilitating wetting of the mass of molten metal with the one of the contact pads of said microelectronic element.

21. The method as claimed in claim 20, wherein said dispensing tool has a C4NP configuration.

22. The method as claimed in claim 20, further comprising pressurizing the molten metal within said dispensing tool prior to the dispensing step.

23. The method as claimed in claim 20, wherein the applying ultrasonic waves step comprises applying ultrasonic waves at a frequency of around 20 kHz to 100 MHz.

24. The method as claimed in claim 20, wherein said dispensing tool comprises:

a chamber for holding the molten metal, the chamber being in communication with the discharge port; and

an ultrasonic transducer in contact with said dispensing tool for producing ultrasonic waves in the chamber.

25. The method as claimed in claim 20, further comprising:

providing a planar element over the front face of said microelectronic element, said planar element having at least one opening extending therethrough;

aligning the at least one opening in said planar element with the one of the contacts on said microelectronic element;

aligning the discharge port of said dispensing tool with the at least one opening extending through said planar element.

26. The method as claimed in claim 25, wherein said planar element is connected with said microelectronic element.

27. The method as claimed in claim 25, wherein said planar element is connected with said dispensing tool.

28. The method as claimed in claim 20, wherein said microelectronic element is selected from the group consisting of semiconductor wafers, semiconductor chips and circuitized substrates.

29. The method as claimed in claim 20, further comprising:

connecting an ultrasonic transducer with said dispensing tool; and

operating said ultrasonic transducer during the dispensing step for applying ultrasonic waves to the mass of molten metal.

30. The method as claimed in claim 29, wherein said ultrasonic transducer is coupled with the discharge port of said dispensing tool.

31. The method as claimed in claim 20, further comprising dispensing a mass of the molten metal onto a plurality of the contact pads of said microelectronic element.