Flange for integrated circuit package
A circuit package for housing semiconductor or other integrated circuit devices (“die”) includes a high-copper flange, one or more high-copper leads and a liquid crystal polymer frame molded to the flange and the leads. The flange includes a dovetail-shaped groove or other frame retention feature that mechanically interlocks with the molded frame. During molding, a portion of the frame forms a key that freezes in or around the frame retention feature.
1. A flange for mounting a semiconductor die, comprising:
a solid metallic body having:
a central planar die-attach area on a first side thereof, the die-attach area being flat to within about 0.005 inches per inch and having a surface roughness less than about 64 micro-inches; and
a second side, opposite the first side, having a surface roughness less than about 64 micro-inches; wherein:
the metallic body comprises at least 50% copper.
2. The flange of claim 1 , wherein the metallic body defines a plurality of openings by which the flange can be mounted to a substrate.
3. The flange of claim 1 , wherein the metallic body comprises at least 90% copper.
4. The flange of claim 1 , wherein the metallic body comprises at least about 98% copper.
5. The flange of claim 1 , wherein the metallic body comprises an alloy of copper and at least one material chosen from a group comprising zirconium and silver.
6. The flange of claim 1 , wherein the metallic body comprises an alloy containing at least about 98% copper.
7. The flange of claim 6 , wherein the alloy contains between about 0.05% and about 1.5% zirconium and at least about 98.5% copper.
8. The flange of claim 6 , wherein the alloy contains about 0.085% silver and at least about 99.9% copper.
9. The flange of claim 1 , wherein the metallic body includes a recess that defines at least one undercut portion.
10. The flange of claim 9 , wherein the recess includes a portion having a dovetail-shaped cross-section.
11. The flange of claim 9 , wherein the recess includes a portion having a T-shaped cross-section.
12. The flange of claim 9 , wherein the recess includes a portion having an L-shaped cross-section.
13. The flange of claim 1 , wherein the metallic body includes a ridge that defines at least one undercut portion.
14. The flange of claim 13 , wherein the ridge includes a portion having a dovetail-shaped cross-section.
15. The flange of claim 13 , wherein the ridge includes a portion having a T-shaped cross-section.
16. The flange of claim 13 , wherein the ridge includes a portion having an L-shaped cross-section.
17. The flange of claim 1 , wherein the second side of the body is convex.
18. The flange of claim 17 , wherein convexity of the second side is at least about 0.0001 inches.
19. The flange of claim 17 , wherein convexity of the second side is between about 0.0005 and about 0.0010 inches.
20. A flange for mounting a semiconductor die, comprising:
a solid metallic body having:
a central planar die-attach area on a first side thereof, the die-attach area being flat to within about 0.005 inches per inch and having a surface roughness less than about 64 micro-inches; and
a second side, opposite the first side, has a surface roughness less than about 64 micro-inches and is convex.
21. The flange of claim 20 , wherein the metallic body defines a plurality of openings by which the flange can be mounted to a substrate.
22. The flange of claim 20 , wherein convexity of the second side is at least about 0.0001 inches.
23. The flange of claim 20 , wherein convexity of the second side is between about 0.0005 and about 0.00010 inches.
24. The flange of claim 20 , wherein the metallic body comprises at least 50% copper.
25. The flange of claim 20 , wherein the metallic body comprises at least 90% copper.
26. The flange of claim 20 , wherein the metallic body comprises at least about 98% copper.
27. The flange of claim 20 , wherein the metallic body comprises an alloy of copper and at least one material chosen from a group comprising zirconium and silver.
28. The flange of claim 20 , wherein the metallic body comprises an alloy containing at least about 98% copper.
29. The flange of claim 28 , wherein the alloy contains between about 0.05% and about 1.5% zirconium and at least about 98.5% copper.
30. The flange of claim 28 , wherein the alloy contains about 0.085% silver and at least about 99.9% copper.
31. A flange for mounting a semiconductor die, comprising:
a solid metallic body having:
a central planar die-attach area on a first side thereof, the die-attach area being flat to within about 0.005 inches per inch and having a surface roughness less than about 64 micro-inches; and
a second side, opposite the first side, having a surface roughness less than about 64 micro-inches; wherein:
the metallic body includes a recess that defines at least one undercut portion.
32. The flange of claim 31 , wherein the metallic body defines a plurality of openings by which the flange can be mounted to a substrate.
33. The flange of claim 31 , wherein the recess includes a portion having a dovetail-shaped cross-section.
34. The flange of claim 31 , wherein the recess includes a portion having a T-shaped cross-section.
35. The flange of claim 31 , wherein the recess includes a portion having an L-shaped cross-section.
36. The flange of claim 31 , wherein the metallic body comprises at least 50% copper.
37. The flange of claim 31 , wherein the metallic body comprises at least 90% copper.
38. The flange of claim 31 , wherein the metallic body comprises at least about 98% copper.
39. The flange of claim 31 , wherein the metallic body comprises an alloy of copper and at least one material chosen from a group comprising zirconium and silver.
40. The flange of claim 31 , wherein the metallic body comprises an alloy containing at least about 98% copper.
41. The flange of claim 40 , wherein the alloy contains between about 0.05% and about 1.5% zirconium and at least about 98.5% copper.
42. The flange of claim 41 , wherein the alloy contains about 0.085% silver and at least about 99.9% copper.
43. A flange for mounting a semiconductor die, comprising:
a solid metallic body having:
a central planar die-attach area on a first side thereof, the die-attach area being flat to within about 0.005 inches per inch and having a surface roughness less than about 64 micro-inches; and
a second side, opposite the first side, having a surface roughness less than about 64 micro-inches; wherein:
the metallic body includes a ridge that defines at least one undercut portion.
44. The flange of claim 43 , wherein the metallic body defines a plurality of openings by which the flange can be mounted to a substrate.
45. The flange of claim 43 , wherein the ridge includes a portion having a dovetail-shaped cross-section.
46. The flange of claim 43 , wherein the ridge includes a portion having a T-shaped cross-section.
47. The flange of claim 43 , wherein the ridge includes a portion having an L-shaped cross-section.
48. The flange of claim 43 , wherein the metallic body comprises at least 50% copper.
49. The flange of claim 43 , wherein the metallic body comprises at least 90% copper.
50. The flange of claim 43 , wherein the metallic body comprises at least about 98% copper.
51. The flange of claim 43 , wherein the metallic body comprises an alloy of copper and at least one material chosen from a group comprising zirconium and silver.
52. The flange of claim 43 , wherein the metallic body comprises an alloy containing at least about 98% copper.
53. The flange of claim 52 , wherein the alloy contains between about 0.05% and about 1.5% zirconium and at least about 98.5% copper.
54. The flange of claim 53 , wherein the alloy contains about 0.085% silver and at least about 99.9% copper.