Method and apparatus for fabricating printed circuit board using atmospheric pressure capillary discharge plasma shower

• US 20020148816A1
• Filed: 08/23/2001
• Published: 10/17/2002
• Est. Priority Date: 04/17/2001
• Status: Abandoned Application

• Current Assignee: Plasmion GmbH, Simmtech Corporation
• Original Assignee: Plasmion GmbH, Simmtech Corporation
• Inventors: So, Hyun Jo, Jung, Chang Bo, Kim, Steven, Jeong, Jong Han, Yu, Dong Woo
• Application Number:
  US09/935,047
• Publication Number:
  US 20020148816A1
• Time in Patent Office: Days
• US Class Current: 219/121.41
• CPC Class Codes: H01J 2237/3355 Holes or apertures, i.e. inprinted circuit boards
• CPC Class Codes: H01J 37/32009 Arrangements for generation of plasma specially adapted for examination or treatment of objects, e.g. plasma sources plasma generation in general H05H1/24
• CPC Class Codes: H01J 37/32541 Shape
• 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 3/0035 of blind holes, i.e. having a metal layer at the bottom
• CPC Class Codes: H05K 3/0055 After-treatment, e.g. cleaning or desmearing of holes
• CPC Class Codes: H05K 3/26 Cleaning or polishing of the conductive pattern
• CPC Class Codes: H05K 3/3489 Composition of fluxes; Methods of application thereof; Other methods of activating the contact surfaces

Abstract

A method and apparatus for treating a workpiece using capillary discharge plasma are disclosed in the present invention. More specifically, a method of desmearing holes in a copper laminated board and forming a conductive material in the holes using an atmospheric pressure capillary discharge plasma apparatus having at least one first electrode receiving a power source, a dielectric body having first and second sides, the first side coupled to the first electrode and the second side having at least one capillary extending to a direction of the first side of the dielectric body, and each capillary substantially aligned with each electrode, and a second electrode electrically coupled to the first electrode, the method comprising the steps of drilling the copper laminated board to remove at least a portion of the copper laminated board, placing the copper laminated board having the holes in the apparatus, applying a potential to the plasma generator, providing a working gas in close proximity to the copper laminated board, generating capillary discharge plasma out of the capillary, thereby treating the copper laminated board with the atmospheric pressure capillary discharge plasma to remove resin residues in the holes, and forming the conductive material on the copper laminated board including in the holes.

Claims

1. A method of fabricating a printed circuit board for desmearing holes in a copper laminated board and forming a conductive material in the holes using an atmospheric pressure capillary discharge plasma apparatus having at least one first electrode receiving a power source, a dielectric body having first and second sides, the first side coupled to the first electrode and the second side having at least one capillary extending to a direction of the first side of the dielectric body, and each capillary substantially aligned with each electrode, and a second electrode electrically coupled to the first electrode, the method comprising the steps of:

drilling the copper laminated board to remove at least a portion of the copper laminated board;

placing the copper laminated board having the holes in the apparatus;

applying a potential to the plasma generator;

providing a working gas in close proximity to the copper laminated board;

generating capillary discharge plasma out of the capillary, thereby treating the copper laminated board with the atmospheric pressure capillary discharge plasma to remove resin residues in the holes; and

forming the conductive material on the copper laminated board including in the holes.

2. The method according to claim 1, wherein the applied potential is in the range of about 0.5 and 5 kW.

3. The method according to claim 1, wherein the applied potential has a frequency in the range of about 1 and 500 kHz.

4. The method according to claim 1, wherein the working gas includes one of Ar, He, O₂, and air, and any mixture of Ar, He, O₂, and air.

5. The method according to claim 4, wherein the any mixture includes 30 to 60% Ar, 30 to 60% O₂, and 5 to 30% He.

6. The method according to claim 1, further comprising the step of simultaneously providing a reaction enhancing gas with the working gas.

7. The method according to claim 6, wherein the reaction enhancing gas includes 5 to 30% CF₄.

8. The method according to claim 6, wherein the step of drilling the copper laminated board forms either via holes or through holes in the board.

9. The method according to claim 1, wherein the step of drilling the copper laminated board includes one of a laser drilling and a mechanical drilling.

13. The method according to claim 9, wherein the working gas includes one of Ar, He, O₂, CF₄, H₂, and air, and any mixture of Ar, He, O₂, H₂, CF₄, and air.

10. A method of fabricating a printed circuit board for forming a solder mask on a copper laminated board using an atmospheric pressure capillary discharge plasma apparatus having at least one first electrode receiving a power source, a dielectric body having first and second sides, the first side coupled to the first electrode and the second side having at least one capillary extending to a direction of the first side of the dielectric body, and each capillary substantially aligned with each electrode, and a second electrode electrically coupled to the first electrode, the method comprising the steps of:

forming a circuit pattern on the copper laminated board;

placing the copper laminated board in the apparatus;

applying a potential to the plasma generator;

providing a working gas in close proximity to the copper laminated board;

generating capillary discharge plasma out of the capillary, thereby treating the copper laminated board with the atmospheric pressure capillary discharge plasma;

forming a solder mask material on the treated copper laminated board including the circuit pattern; and

curing the solder mask material to form a solder mask on the copper laminated board.

11. The method according to claim 10, wherein the applied potential is in the range of about 0.5 and 5 kW.

12. The method according to claim 10, wherein the applied potential has a frequency in the range of about 1 to 500 kHz.

14. The method according to claim 13, wherein one of the mixture includes 30 to 60% Ar, 30 to 60% O₂, 5 to 30% CF₄, and 5 to 30% He.

15. The method according to claim 13, further comprising the step of simultaneously providing a reaction enhancing gas with the working gas.

16. The method according to claim 15, wherein the reaction enhancing gas includes 0 to 30% H₂.

18. The method according to claim 17, wherein the applied potential has a power in the range of about 0.5 and 5 kW.

19. The method according to claim 17, wherein the applied potential has a frequency in the range of about 1 to 500 kHz.

20. The method according to claim 17, wherein the working gas includes one of Ar, He, O₂, CF₄, H₂, and air, and any mixture of Ar, He, O₂, CF₄, H₂, and air.

21. The method according to claim 20, wherein one of the mixture includes 30 to 60% Ar, 30 to 60% O₂, 5 to 30% CF₄, and 5 to 30% He.

22. The method according to claim 17, further comprising the step of simultaneously providing a reaction enhancing gas with the working gas.

23. The method according to claim 17, wherein the reaction enhancing gas includes 0 to 30% H₂.

25. The method according to claim 24, wherein the applied potential is in the range of about 0.5 and 5 kW.

26. The method according to claim 24, wherein the applied potential has a frequency in the range of about 1 to 500 kHz.

27. The method according to claim 24, wherein the working gas includes one of Ar, He, O₂, H₂, and air, and any mixture of Ar, He, O₂, H₂, and air.

28. The method according to claim 27, wherein one of the mixture includes 30 to 60% Ar, 30 to 60% O₂, and 5 to 30% He.

29. The method according to claim 24, further comprising the step of simultaneously providing a reaction enhancing gas with the working gas.

30. The method according to claim 29, wherein the reaction enhancing gas includes 5 to 30% H₂ and 5 to 30% CF₄.

31. The method according to claim 24, wherein the conductive layer includes a Ni/Au layer.

17. A method of fabricating a printed circuit board for forming a circuit pattern on a copper laminated board using an atmospheric pressure capillary discharge plasma apparatus having at least one first electrode receiving a power source, a dielectric body having first and second sides, the first side coupled to the first electrode and the second side having at least one capillary extending to a direction of the first side of the dielectric body, and each capillary substantially aligned with each electrode, and a second electrode electrically coupled to the first electrode, the method comprising the steps of:

pre-treating the copper laminated board;

laminating a dry film resist on the pretreated copper laminated board;

patterning the dry film resist on the copper laminated board;

selectively removing a copper on the copper laminated board using the patterned dry film resist as a mask;

stripping the patterned dry film resist from the copper laminated board;

placing the copper laminated board in the apparatus;

applying a potential to the plasma-generator;

providing a working gas in close proximity to the copper laminated board; and

generating capillary discharge plasma out of the capillary, thereby treating the copper laminated board with the atmospheric pressure capillary discharge plasma to remove residues of the dry film resist on the copper laminated board.

24. A method of fabricating a printed circuit board for wire bonding to the printed circuit board using an atmospheric pressure capillary discharge plasma apparatus having at least one first electrode receiving a power source, a dielectric body having first and second sides, the first side coupled to the first electrode and the second side having at least one capillary extending to a direction of the first side of the dielectric body, and each capillary substantially aligned with each electrode, and a second electrode electrically coupled to the first electrode, the method comprising the steps of:

plating a conductive layer on the printed circuit board;

processing a surface of the conductive layer as desired;

cleaning the processed conductive layer;

placing the copper laminated board in the apparatus;

applying a potential to the plasma generator;

providing a working gas in close proximity to the copper laminated board;

generating capillary discharge plasma out of the capillary, thereby treating the conductive layer with the atmospheric pressure capillary discharge plasma to remove contaminants on the surface the conductive layer; and

bonding a wire or a solder ball to the treated conductive layer.

32. An apparatus for fabricating a printed circuit board using atmospheric pressure capillary discharge plasma shower, comprising:

a loading unit for loading and transferring the printed circuit board;

a process unit for treating the printed circuit board including at least one atmospheric plasma generator having at least one first electrode receiving a power source, a dielectric body having first and second sides, the first side coupled to the first electrode and the second side having at least one capillary extending to a direction of the first side of the dielectric body, and each capillary substantially aligned with each electrode, and a second electrode electrically coupled to the first electrode;

a display unit for displaying working conditions of the apparatus; and

an unloading unit for transferring the treated printed circuit board.

33. The apparatus according to claim 32, further comprising a working gas source for providing a working gas with the process unit.

34. The apparatus according to claim 32, further comprising a transferring mechanism for transferring the apparatus to a desired position.