Composition and method for reducing copper oxide to metallic copper

• US 6,086,956 A
• Filed: 01/19/1999
• Issued: 07/11/2000
• Est. Priority Date: 12/19/1995
• Status: Expired due to Fees

• Current Assignee: ROHM and HAAS Chemicals LLC (Dow, Inc.)
• Original Assignee: Morton International Incorporated (Autoliv Incorporated)
• Inventors: Campbell, Scott, Rush, Michael, Fakler, John
• Primary Examiner(s): NGUYEN, NGOC YEN M
• Application Number:
  US09/232,968
• Time in Patent Office: 539 Days
• Field of Search: 423/604, 427/299, 427/399, 427/444, 427/409, 427/327, 427/328, 148/276, 148/277, 148/282
• US Class Current: 427/299
• CPC Class Codes: C07F 5/00 Compounds containing elements of Groups 3 or 13 of the Periodic Table
• CPC Class Codes: C07F 5/022 without C-boron linkages
• CPC Class Codes: C23C 22/63 Treatment of copper or alloys based thereon
• CPC Class Codes: C23C 22/83 Chemical after-treatment
• CPC Class Codes: H05K 2203/0315 Oxidising metal
• CPC Class Codes: H05K 2203/1157 Using means for chemical reduction
• CPC Class Codes: H05K 3/385 by conversion of the surface of the metal, e.g. by oxidation, whether or not followed by reaction or removal of the converted layer

Abstract

A composition for reducing a copper oxide layer to metallic copper so as to facilitate bonding a resin to the metallic copper is disclosed. The composition is an aqueous reducing solution containing a cyclic borane compound. Examples of such cyclic borane compounds include those having nitrogen or sulfur as a ring-forming member, such as morpholine borane, piperidine borane, pyridine borane, piperazine borane, 2,6-Iutidine borane, 4-methylmorpholine borane, and 1,4-oxathiane borane, and also N,N-diethylaniline borane.

Claims

1. In a method of bonding copper and a resin together wherein a copper oxide layer is reduced and the reduced copper oxide layer is bonded to a resin, the improvement comprising reducing the copper oxide layer with an aqueous reducing agent solution containing a cyclic borane compound under conditions which produce a weight loss greater than 15%.

2. The improvement of claim 1, wherein the cyclic borane compound is selected from the group consisting of cyclic borane compounds having nitrogen as a ring-forming members cyclic borane compounds having sulfur as a ring-forming member, and N,N-diethylaniline borane.

3. The improvement of claim 2, wherein the cyclic borane compound is selected from the group consisting of morpholine borane, piperidine borane, pyridine borane, piperazine borane, 2,6-Iutidine borane, 4-ethylmorpholine borane, 4-methylmorpholine borane, and 1,4-oxathiane borane.

4. The improvement of claim 3, wherein the cyclic borane compound is morpholine borane present at a concentration in the range of about 1.0 g/l to saturation.

5. The improvement of claim 4, wherein the morpholine borane present at a concentration in the range of about 2.7 g/l to 16.8 g/l.

6. The improvement of claim 3, wherein the cyclic borane is piperidine borane present at a concentration in the range of about 1.0 g/l to saturation.

7. The improvement of claim 3, wherein the cyclic borane is pyridine borane present at a concentration in the range of about 0.9 g/l to saturation.

8. The improvement of claim 3, wherein the cyclic borane is piperazine borane present at a concentration in the range of about 1.0 g/l to saturation.

9. The improvement of claim 3, wherein the cyclic borane is 2,6-Iutidine borane present at a concentration in the range of about 1.2 g/l to saturation.

10. The improvement of claim 3, wherein the cyclic borane is 4-ethylmorpholine borane present at a concentration in the range of about 1.3 g/l to saturation.

11. The improvement of claim 3, wherein the cyclic borane is 4-methylmorpholine borane present at a concentration in the range of about 1.1 g/l to saturation.

12. The improvement of claim 3, wherein the cyclic borane is 1,4 oxathiane borane present at a concentration in the range of about 1.2 g/l to saturation.

13. The improvement of claim 2, wherein the cyclic borane is N,N-diethylaniline borane present at a concentration in the range of about 1.3 g/l to saturation.

14. The improvement of claim 2, further comprising adding to the reducing solution a reducing stabilizer in an amount sufficient to decrease consumption of the cyclic borane compound during reduction to a level less than that consumed in the absence of the reducing stabilizer during the course of a copper oxide reduction process, wherein the stabilized reduction process is initiated in less than about 4 minutes and the metallic copper layer resulting from the stabilized reduction process is resistant to acid attack.

15. The improvement of claim 14, wherein the reducing stabilizer is thiourea.

16. The improvement of claim 15, wherein thiourea is present at a concentration in the range of about 2.5 ppm to 200 ppm.

69. The method of claim 1 wherein the reducing is carried out under conditions which produce a weight loss of about 20%.

17. A method for reducing copper oxide to improve acid resistance comprising reacting copper oxide with an aqueous reducing solution containing a cyclic borane compound, said reacting step is continued until a weight loss greater than 15% is achieved.

18. The method of claim 17, wherein said cyclic borane compound is a member selected from the group consisting of morpholine borane and piperazine borane.

70. The method of claim 17 wherein the reacting step is continued until a weight loss of about 20% is produced.

19. A method for reducing copper oxide comprising reacting copper oxide with an aqueous reducing solution containing a cyclic borane compound under conditions which result in a weight loss greater than 15%.

20. The method of claim 19, wherein said cyclic borane compound is a member selected from the group consisting of morpholine borane and piperazine borane.

21. The method of claim 19, wherein the cyclic borane compound is selected from the group consisting of cyclic borane compounds having nitrogen as a ring-forming member, cyclic borane compounds having sulfur as a ring-forming member, and N,N-diethylaniline borane.

22. The method of claim 21, wherein the cyclic borane compound is morpholine borane.

23. The method of claim 22, wherein the morpholine borane is present at a concentration in the range of about 1.0 g/l to saturation.

24. The method of claim 23, wherein the morpholine borane is present at a concentration in the range of about 2.7 g/l to 16.8 g/l.

25. The method of claim 21, wherein the cyclic borane compound is piperidine borane.

26. The method of claim 25, wherein the piperidine borane is present at a concentration in the range of about 1.0 g/l to saturation.

27. The method of claim 21, wherein the cyclic borane compound is pyridine borane.

28. The method of claim 27, wherein the pyridine borane is present at a concentration in the range of about 0.9 g/l to saturation.

29. The method of claim 21, wherein the cyclic borane compound is piperazine borane.

30. The method of claim 29, wherein the piperazine borane is present at a concentration in the range of about 1.0 g/l to saturation.

31. The method of claim 21, wherein the cyclic borane compound is 2,6 Iutidine borane.

32. The method of claim 21, wherein the 2,6 Iutidine borane is present at a concentration in the range of about 1.2 g/l to saturation.

33. The method of claim 21, wherein the cyclic borane compound is 4-ethylmorpholine borane.

34. The method of claim 33, wherein the 4-ethylmorpholine borane is present at a concentration in the range of about 1.3 g/l to saturation.

35. The method of claim 21, wherein the cyclic borane compound is 4-methylmorpholine borane.

36. The method of claim 35, wherein the 4-methylmorpholine borane is present at a concentration in the range of about 1.1 g/l to saturation.

37. The method of claim 21, wherein the cyclic borane compound is 1,4 oxathiane borane.

38. The method of claim 37, wherein the 1,4 oxathiane borane is present at a concentration in the range of about 1.2 g/l to saturation.

39. The method of claim 21, wherein the cyclic borane compound is N,N-diethylaniline borane present at a concentration in the range of about 1.3 g/l to saturation.

40. The method of claim 21, further comprising including a reducing stabilizer in the aqueous reducing solution in an amount sufficient to decrease consumption of the cyclic borane compound during reduction to a level less than that consumed in the absence of the reducing stabilizer during the course of a copper oxide reduction process, wherein the stabilized reduction process is initiated in less than about 4 minutes.

41. The method of claim 40, wherein the reducing stabilizer is thiourea.

42. The method of claim 41, wherein thiourea is present at a concentration in the range of about 2.5 ppm to 200 ppm.

73. The method of claim 19 wherein the reducing is carried out under conditions which produce a weight loss of about 20%.

43. A method of reducing a copper oxide layer formed on the surface of a copper substrate to improve acid resistance comprising the step of reacting said copper oxide with a reducing composition comprising an aqueous reducing solution containing a cyclic borane compound, said reacting step is continued until a weight loss of greater than 15% is produced.

44. The method of claim 43, wherein said cyclic borane compound is a member selected from the group consisting of morpholine borane and piperazine borane.

45. The method of claim 43, wherein the cyclic borane compound is selected from the group consisting of cyclic borane compounds having nitrogen as a ring-forming member, cyclic borane compounds having sulfur as a ring-forming member, and N,N-diethylaniline borane.

46. The method of claim 45, wherein the cyclic borane compound is morpholine borane.

47. The method of claim 46, wherein the morpholine borane is present at a concentration in the range of about 1.0 g/l to saturation.

48. The method of claim 47, wherein the morpholine borane is present at a concentration in the range of about 2.7 g/l to 16.8 g/l.

49. The method of claim 45, wherein the cyclic borane compound is piperidine borane.

50. The method of claim 49, wherein the piperidine borane is present at a concentration in the range of about 1.0 g/l to saturation.

51. The method of claim 45, wherein the cyclic borane compound is pyridine borane.

52. The method of claim 51, wherein the pyridine borane is present at a concentration in the range of about 0.9 g/l to saturation.

53. The method of claim 45, wherein the cyclic borane compound is piperazine borane.

54. The method of claim 53, wherein the piperazine borane is present at a concentration in the range of about 1.0 g/l to saturation.

55. The method of claim 45, wherein the cyclic borane compound is 2,6 Iutidine borane.

56. The method of claim 55, wherein the 2,6 Iutidine borane is present at a concentration in the range of about 1.2 g/l to saturation.

57. The method of claim 45, wherein the cyclic borane compound is 4-ethylmorpholine borane.

58. The method of claim 57, wherein the 4-ethylmorpholine borane is present at a concentration in the range of about 1.3 g/l to saturation.

59. The method of claim 45, wherein the cyclic borane compound is 4-methylmorpholine borane.

60. The method of claim 59, wherein the 4-methylmorpholine borane is present at a concentration in the range of about 1.1 g/l to saturation.

61. The method of claim 45, wherein the cyclic borane compound is 1,4 oxathiane borane.

62. The method of claim 61, wherein the 1,4 oxathiane borane is present at a concentration in the range of about 1.2 g/l to saturation.

63. The method of claim 45, wherein the cyclic borane compound is N,N-diethylaniline borane present at a concentration in the range of about 1.3 g/l to saturation.

64. The method of claim 45, further comprising including a reducing stabilizer in the aqueous reducing solution in an amount sufficient to decrease consumption of the cyclic borane compound during reduction to a level less than that consumed in the absence of the reducing stabilizer during the course of a copper oxide reduction process, wherein the stabilized reduction process is initiated in less than about 4 minutes.

65. The method of claim 64, wherein the reducing stabilizer is thiourea.

66. The method of claim 65, wherein thiourea is present at a concentration in the range of about 2.5 ppm to 200 ppm.

71. The method of claim 43 wherein the reacting condition is continued until a weight loss of about 20% is produced.

67. A method for treating copper oxide comprising reacting copper oxide with an aqueous reducing solution containing a cyclic borane compound under conditions which result in a weight loss greater than 15%.

68. The method of claim 67, wherein said cyclic borane compound is selected from the group consisting of morpholine borane and piperazine borane.

72. The method of claim 67 wherein the reacting is carried out under conditions resulting in a weight loss of about 20%.