Method of fabricating an electronic circuit device and apparatus for performing the method

• US 5,878,943 A
• Filed: 11/19/1996
• Issued: 03/09/1999
• Est. Priority Date: 02/19/1990
• Status: Expired due to Fees

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Nishikawa, Toru, Harada, Masahide, Satoh, Ryohei, Hayashida, Tetsuya, Shirai, Mitugu
• Primary Examiner(s): Heinrich, Samuel M.
• Application Number:
  US08/753,018
• Time in Patent Office: 840 Days
• Field of Search: 228/219-221, 228/180.21, 228/180.22, 228/205, 228/207, 228/223, 134/40, 134/42
• US Class Current: 228/205
• CPC Class Codes: B23K 1/0016 Brazing of electronic components
• CPC Class Codes: B23K 2101/40 Semiconductor devices
• 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 21/563 Encapsulation of active face of flip-chip device, e.g. underfilling or underencapsulation of flip-chip, encapsulation preform on chip or mounting substrate
• CPC Class Codes: H01L 21/6835 using temporarily an auxiliary support
• CPC Class Codes: H01L 2224/11003 for holding or transferring the bump preform
• CPC Class Codes: H01L 2224/13099 Material
• CPC Class Codes: H01L 2224/16225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/73203 Bump and layer connectors
• CPC Class Codes: H01L 2224/81012 Mechanical cleaning, e.g. abrasion using hydro blasting, brushes, ultrasonic cleaning, dry ice blasting, gas-flow
• CPC Class Codes: H01L 2224/81075 being inert
• CPC Class Codes: H01L 24/11 Manufacturing methods for bumps on insulating substrates H01L21/4853
• CPC Class Codes: H01L 24/12 Structure, shape, material or disposition of the bump connectors prior to the connecting process
• CPC Class Codes: H01L 24/16 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 2924/01005 Boron [B]
• CPC Class Codes: H01L 2924/01006 Carbon [C]
• CPC Class Codes: H01L 2924/01015 Phosphorus [P]
• CPC Class Codes: H01L 2924/01018 Argon [Ar]
• CPC Class Codes: H01L 2924/01032 Germanium [Ge]
• CPC Class Codes: H01L 2924/01033 : Arsenic [As]
• CPC Class Codes: H01L 2924/01039 : Yttrium [Y]
• CPC Class Codes: H01L 2924/01042 : Molybdenum [Mo]
• CPC Class Codes: H01L 2924/01047 : Silver [Ag]
• CPC Class Codes: H01L 2924/01054 : Xenon [Xe]
• 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 2924/014 : Solder alloys
• CPC Class Codes: H01L 2924/12042 : LASER
• 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 2924/16152 : Cap comprising a cavity for hosting the device, e.g. U-shaped cap
• CPC Class Codes: H01L 2924/3025 : Electromagnetic shielding
• CPC Class Codes: H05K 2203/086 : Using an inert gas
• CPC Class Codes: H05K 2203/087 : Using a reactive gas
• CPC Class Codes: H05K 2203/095 : Plasma, e.g. for treating a substrate to improve adhesion with a conductor or for cleaning holes
• CPC Class Codes: H05K 2203/1157 : Using means for chemical reduction
• CPC Class Codes: H05K 3/3489 : Composition of fluxes; Methods of application thereof; Other methods of activating the contact surfaces

Abstract

In soldering together two members such as electronic circuit devices, after an oxide or contaminated layer has been removed from the surface of a solder material or bonding pad, for example, the members are aligned in an oxidizing atmosphere. Then the solder material is heated in a nonoxidizing atmosphere to melt the solder and bond the members. Cleaning of the solder material or bonding pad is performed by sputter-cleaning, laser cleaning, mechanical polishing, or cutting.

Claims

1. A method of soldering for use in fabricating an electronic circuit device, comprising the steps of:

removing at least one of an oxide layer and a contamination layer from respective surfaces of a solder material and at least one member to be connected thereto;

supplying said at least one member and said solder material with organic material;

aligning said at least one member and said solder material in an oxidizing atmosphere; and

heating said solder material in a nonoxidizing atmosphere to melt the solder material.

2. A method of soldering as claimed in claim 1, wherein said removing step is performed by sputter-cleaning using at least one of atom and ion beam irradiation.

3. A method of soldering as claimed in claim 1, wherein said removing step is performed mechanically.

4. A method of soldering as claimed in claim 1, wherein said removing step is performed by laser beam cleaning.

5. A method of soldering as claimed in claim 1, wherein said solder material is at least one selected from a group consisting of alloys of Pb and Sn, alloys of Sn and Ag, alloys of Au and Pb, alloys of Au and Ge, and alloys of Au and Si.

6. A method of soldering as claimed in claim 1, wherein said aligning step is performed in an oxidizing atmosphere for at most six hours.

7. A method of soldering as claimed in claim 1, wherein said nonoxidizing atmosphere is prepared by supplying a nonoxidizing gas to a vacuum atmosphere.

8. A method of soldering as claimed in claim 7, wherein said nonoxidizing gas is an inert gas.

9. A method of soldering as claimed in claim 8, wherein said inert gas is selected from the group consisting of (1) N₂, (2) Ar, (3) He, and (4) a mixture of N₂, Ar, and He.

10. A method of soldering as claimed in claim 8, wherein said inert gas is selected from the group consisting of (1) N₂, (2) Ar, (3) He, and (4) a mixture thereof;

and wherein said heating step atmosphere is controlled by controlling the pressure of said vacuum atmosphere and the concentration of said nonoxidizing gas.

11. A method of soldering as claimed in claim 8, wherein said nonoxidizing gas is a reducing gas.

12. A method of soldering as claimed in claim 8, wherein said nonoxidizing gas is an active gas.

13. A method of soldering as claimed in claim 12, wherein said active gas is selected from the group consisting of (1) a mixture of H₂ and N₂ and (2) H₂.

14. A method of soldering as claimed in claim 8, wherein said nonoxidizing gas is a fluorocarbon vapor.

15. A method of soldering as claimed in claim 1, wherein said aligning step is performed in an oxidizing atmosphere for at most 8 hours.

16. A method of soldering as claimed in claim 1, wherein said aligning step is performed in an oxidizing atmosphere for a time sufficiently limited such that an oxide layer formed on the solder material during the aligning step has a thickness of at most 5 nm.

17. A method of soldering as claimed in claim 1, wherein said aligning step is performed by fitting protrusions formed on at least one member in recesses formed by protrusions formed on another member.

18. A method of soldering as claimed in claim 1, wherein said heating step is performed to segment any oxide layer formed on the solder material during the aligning step so as to expose the solder material.

19. A method of soldering as claimed in claim 1, wherein after said aligning step, organic material is present on said at least one member and said solder material.

20. A method of soldering as claimed in claim 1, wherein after said aligning step, organic material is present in said at least one member and said solder material, and wherein after said heating step, organic material is evaporated.

21. A method of soldering as claimed in claim 1, wherein the melting point of said organic material is higher than that of said solder material.

22. A method of soldering as claimed in claim 1, wherein said organic material contains hydroxyl groups in its molecules.

23. A method of soldering as claimed in claim 1, wherein said heating step atmosphere is controlled by controlling the pressure of said vacuum and the concentration of said nonoxidizing gas, and wherein after said heating step, organic material is evaporated.

24. A method of soldering for use in fabricating an electronic circuit device, comprising the steps of:

removing at least one of an oxide layer and a contamination layer from respective surfaces of a solder material and at least one member to be connected thereto;

oxidizing said surfaces to form a thin oxide layer thereon;

supplying said at least one member and said solder material with organic material;

aligning said at least one member and said solder material; and

heating said solder material in a nonoxidizing atmosphere to melt the solder material.

25. A method of soldering for use in fabricating an electronic circuit device, comprising the steps of:

processing a solder material to ensure that no oxide layer and no contamination layer are present thereon;

supplying said at least one member and said solder material with organic material;

aligning said at least one member and said solder material in an oxidizing atmosphere; and

heating said solder material in a nonoxidizing atmosphere to melt the solder material.

26. A method of soldering as claimed in claim 25, wherein said processing step includes the step of providing solder balls each plated with gold.

27. A method of soldering as claimed in claim 25, wherein said processing step includes the step of removing at least one of an oxide layer and a contamination layer from the surface of said solder material.