Metal jet deposition system

• US 6,076,723 A
• Filed: 08/19/1998
• Issued: 06/20/2000
• Est. Priority Date: 08/19/1998
• Status: Expired due to Term

• Current Assignee: Hewlett-Packard Company (HP Inc.)
• Original Assignee: Hewlett-Packard Company (HP Inc.)
• Inventors: I-Tsung Pan, Alfred
• Primary Examiner(s): Ryan, Patrick
• Assistant Examiner(s): Pittman, Zidia T.
• Application Number:
  US09/136,551
• Time in Patent Office: 671 Days
• Field of Search: 228/33, 228/180.21, 347/43, 266/237
• US Class Current: 228/33
• CPC Class Codes: B23K 2101/42 Printed circuits
• CPC Class Codes: B23K 3/0607 Solder feeding devices
• CPC Class Codes: C23C 4/123 Spraying molten metal
• CPC Class Codes: H01L 21/4867 Applying pastes or inks, e.g. screen printing H01L21/486 takes precedence
• CPC Class Codes: H01L 2224/05001 Internal layers
• 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 2224/05147 Copper [Cu] as principal constituent
• CPC Class Codes: H01L 2224/05568 the whole external layer protruding from the surface
• CPC Class Codes: H01L 2224/05599 Material
• CPC Class Codes: H01L 2224/13099 Material
• CPC Class Codes: H01L 24/11 Manufacturing methods for bumps on insulating substrates H01L21/4853
• 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 2924/01013 Aluminum [Al]
• CPC Class Codes: H01L 2924/01018 Argon [Ar]
• CPC Class Codes: H01L 2924/01029 Copper [Cu]
• CPC Class Codes: H01L 2924/01033 Arsenic [As]
• CPC Class Codes: H01L 2924/01079 Gold [Au]
• CPC Class Codes: H01L 2924/01082 Lead [Pb]
• CPC Class Codes: H01L 2924/014 Solder alloys
• CPC Class Codes: H01L 2924/14 : Integrated circuits
• CPC Class Codes: H05K 2203/013 : Inkjet printing, e.g. for printing insulating material or resist using ink-jet printing to form a conductive pattern H05K3/125
• CPC Class Codes: H05K 2203/086 : Using an inert gas
• CPC Class Codes: H05K 3/125 : by ink-jet printing
• CPC Class Codes: H05K 3/14 : using spraying techniques to apply the conductive material , e.g. vapour evaporation
• CPC Class Codes: H05K 3/3457 : Solder materials or compositions; Methods of application thereof

Abstract

A metal jet, metal deposition system has metal jets disposed in an oxygen-free chamber. The metal jets eject droplets of a wetting metal onto conductors on an electrical substrate followed by solder metal. Banks of metal jets can be used to print conductors onto the electrical substrate.

Claims

1. A metal deposition system for conductor bearing substrates, comprising:

a system for providing a space substantially free from oxygen;

a first ejection system in said space for a directing a preparatory material to wet the conductor on the substrate; and

a second ejection system in said space for directing a bonding material to overlay said preparatory material.

2. The system as claimed in claim 1 wherein said system for providing said space fills said space with an inert gas.

3. The system as claimed in claim 1 wherein said first ejection system directs a preparatory material which is reductant for reducing oxides on the conductor.

4. The system as claimed in claim 1 wherein said second ejection system directs a bonding material which is a solder for bonding conductors together.

5. The system as claimed in claim 1 wherein said first and second ejection systems direct microjets of said preparatory and bonding materials to the substrate.

6. The system as claimed in claim 1 wherein the first ejection system has a plurality of microjet heads for providing and directing a plurality of microdrops of said preparatory material to the substrate.

7. The system as claimed in claim 1 wherein the second ejection system has a plurality of microjet heads for providing and directing a plurality of microdrops of said bonding material to the substrate.

8. A metal deposition system for conductor bearing substrates, comprising:

a system providing a chamber substantially free from oxygen;

a first ejection system in said chamber for a directing a wetting metal to wet the conductor on the substrate; and

a second ejection system in said chamber for directing a solder to overlay said wetting metal.

9. The system as claimed in claim 8 wherein said system providing said chamber includes a vacuum pump for evacuating said chamber.

10. The system as claimed in claim 8 wherein said system providing said chamber includes a system for filling said chamber with an inert gas.

11. The system as claimed in claim 10 wherein said inert gas is nitrogen.

12. The system as claimed in claim 10 wherein said inert gas is argon.

13. The system as claimed in claim 8 wherein said first ejection system directs a wetting metal which is reductant for reducing oxides on the conductor.

14. The system as claimed in claim 13 wherein said wetting metal is tin heated past the melting point of tin.

15. The system as claimed in claim 8 wherein said second ejection system directs a solder of a tin-lead alloy heated past the melting point of said alloy.

16. The system as claimed in claim 8 wherein said first and second ejection systems direct liquid microjets of said wetting and solder metals to the substrate in controlled patterns.

17. The system as claimed in claim 8 wherein the first ejection system has a plurality of microjet heads for providing and directing a plurality of liquid microdrops of said wetting metal to the substrate.

18. The system as claimed in claim 8 wherein the second ejection system has a plurality of microjet heads for providing and directing a plurality of liquid microdrops of said solder to the substrate.

19. A solder bumping system for conductor bearing silicon wafers, comprising:

a system for providing a space substantially free from oxygen;

a first ejection system in said space for a directing a tin metal to wet the conductor on the wafer; and

a second ejection system in said space for directing a tin-lead alloy to overlay said tin metal.

20. A conductor application system for conductor bearing printed circuit board, comprising:

a system for providing a space substantially free from oxygen;

a first ejection system in said space for a directing a wetting metal to wet the conductor on the printed circuit board; and

a second ejection system in said space for directing a conductor to overlay said wetting metal and to form conductor lines on said printed circuit board to connect the conductors thereon.