IP Library › Granted Patent US 6,841,858

Granted Patent B2

US 6,841,858 · App. 10/256,407 · Granted Jan 11, 2005

Leadframe for die stacking applications and related die stacking concepts

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Quick Facts

Patent No.: US 6,841,858
App. No.: 10/256,407
Granted: Jan 11, 2005
Kind: B2

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Abstract

A leadframe design (and method of forming the leadframe design), comprising: an inner die pad structure lying in a first plane; and an outer die pad structure supported by outer tie bars and connected to the inner die pad by inner tie bars. The outer die pad structure lying in a second plane spaced apart from the inner die pad structure first plane. An outer package surrounds at least the inner die pad structure and the inner tie bars. The outer die pad structure being supported by the outer tie bars. The outer package having outer walls. Lead fingers extend through the outer package outer walls and include respective inner portions extending into the outer package proximate the inner and outer die pad structures. The inner portions of the lead fingers lie in a third plane, wherein at least one of the inner die pad structure first plane and the outer die pad structure second plane lie outside of the lead finger inner portions third plane and wherein a first chip is affixed to the inner die pad structure and a second chip is affixed to the outer die pad structure.

Claims (162)

1. A leadframe design, comprising:

an inner die pad structure lying in a first plane;

an outer die pad structure lying in a second plane spaced apart from the inner die pad structure first plane and connected to the inner die pad by inner tie bars, the outer die pad structure is ring shaped and surrounds the inner die pad structure;

an outer package surrounding at least the inner die pad structure and the inner tie bars; the outer die pad structure being supported by outer tie bars; the outer package having outer walls; and

2. The leadframe design of claim 1 , wherein the first chip is affixed to the inner die pad structure by resin and the second chip is affixed to the outer die pad structure by resin.

3. The leadframe design of claim 1 , wherein the inner die pad structure is rectangular in shape.

4. The leadframe design of claim 1 , wherein the inner die pad structure is spaced a distance below the lead finger inner portions and the outer die pad structure is coplanar with the lead finger inner portions.

5. The leadframe design of claim 1 , wherein the inner die pad structure is spaced from about 100 to 1000 μm below the lead finger inner portions.

6. The leadframe design of claim 1 , wherein the inner die pad structure is spaced from about 200 to 500 μm below the lead finger inner portions.

7. The leadframe design of claim 1 , wherein the inner die pad structure is spaced a distance below the lead finger inner portions; the outer die pad structure is coplanar with the lead finger inner portions; the first and second chips and the lead finger inner portions each have respective upper surfaces; the first chip connected to the lead finger inner portions by respective lower lead wires affixed to the upper surface of the first chip and the upper surfaces of the lead finger inner portions; and the second chip connected to the lead finger inner portions by respective upper lead wires affixed to the upper surface of the second chip and the upper structures of the lead finger inner portions.

8. The leadframe design of claim 1 , wherein the outer die pad structure is spaced a first distance below the lead finger inner portions and the inner die pad structure is spaced a second distance below the lead finger inner portions; the second distance being greater than the first distance.

9. The leadframe design of claim 1 , wherein the outer die pad structure is spaced from about 300 to 1000 μm below the lead finger inner portions and the inner die pad structure is spaced from about 350 to 800 μm below the lead finger inner portions.

10. The leadframe design of claim 1 , wherein the outer die pad structure is spaced from about 150 to 500 μm below the lead finger inner portions and the inner die pad structure is spaced from about 150 to 300μbelow the lead finger inner portions.

11. The leadframe design of claim 1 , wherein the outer die pad structure is spaced a first distance below the lead finger inner portions and the inner die pad structure is spaced a second distance below the lead finger inner portions; the second distance being greater than the first distance; the first and second chips and the lead finger inner portions each have respective upper surfaces; the first chip connected to the lead finger inner portions by respective lower lead wires affixed to the upper surface of the first chip and the upper surfaces of the lead finger inner portions; and the second chip connected to the lead finger inner portions by respective upper lead wires affixed to the upper surface of the second chip and the upper surfaces of the lead finger inner portions.

12. The leadframe design of claim 1 , wherein the outer die pad structure is spaced a distance above the lead finger inner portions and the inner die pad structure is coplanar with the lead finger inner portions.

13. The leadframe design of claim 1 , wherein the outer die pad structure is spaced from about 100 to 800 μm above the lead finger inner portions.

14. The leadframe design of claim 1 , wherein the outer die pad structure is spaced from about 200 to 500 μm above the lead finger inner portions.

15. The leadframe design of claim 1 , wherein the outer die pad structure is spaced a distance above the lead finger inner portions and the inner die pad structure is coplanar with the lead finger inner portions; the first and second chips and the lead finger inner portions each have respective upper surfaces; the first chip connected to the lead finger inner portions by respective lower lead wires affixed to the upper surface of the first chip and the upper surfaces of the lead finger inner portions; and the second chip connected to the lead finger inner portions by respective upper lead wires affixed to the upper surface of the second chip and the upper surfaces of the lead finger inner portions.

16. The leadframe design of claim 1 , wherein the outer die pad structure is spaced above the lead finger inner portions and the inner die pad structure is spaced below the lead finger inner portions.

17. The leadframe design of claim 1 , wherein the outer die pad structure is spaced from about 100 to 800 μm above the lead finger inner portions and the inner die pad structure is spaced from about 100 to 800 μm below the lead finger inner portions.

18. The leadframe design of claim 1 , wherein the outer die pad structure is spaced from about 200 to 500 μm above the lead finger inner portions and the inner die pad structure is spaced from about 200 to 500 μm below the lead finger inner portions.

19. The leadframe design of claim 1 , wherein the outer die pad structure is spaced above the lead finger inner portions and the inner die pad structure is spaced below the lead finger inner portions; the first and second chips and the lead finger inner portions each have respective upper surfaces; the first chip connected to the lead finger inner portions by respective lower lead wires affixed to the upper surface of the first chip and the upper surfaces of the lead finger inner portions; and the second chip connected to the lead finger inner portions by respective upper lead wires affixed to the upper surface of the second chip and the upper surfaces of the lead finger inner portions.

20. The leadframe design of claim 1 , wherein the outer die pad structure is spaced above the lead finger inner portions and the inner die pad structure is spaced below the lead finger inner portions; the first and second chips and the lead finger inner portions each have respective upper and lower surfaces; the first chip connected to the lead finger inner portions by respective lower lead wires affixed to the lower surface of the first chip and the lower surfaces of the lead finger inner portions; and the second chip connected to the lead finger inner portions by respective upper lead wires affixed to the upper surface of the second chip and the upper surfaces of the lead finger inner portions.

21. The leadframe design of claim 1 , wherein the outer die pad structure is spaced above the lead finger inner portions and the inner die pad structure is spaced below the lead finger inner portions; the inner die pad structure, the first and second chips and the lead finger inner portions each have respective upper and lower surfaces; the first chip connected to the lead finger inner portions by respective lower lead wires affixed to the upper surface of the first chip and the upper surfaces of the lead finger inner portions; the second chip connected to the lead finger inner portions by respective upper lead wires affixed to the upper surface of the second chip and the upper surfaces of the lead finger inner portions; and the inner die pad structure connected to the lead finger inner portions by respective grounding lead wires affixed to the upper surface of the inner die pad structure and the upper surfaces of the lead finger inner portions.

22. The leadframe design of claim 1 , wherein the inner die pad structure is spaced a distance above the lead finger inner portions and the outer die pad structure is spaced a distance below the lead finger inner portions.

23. The leadframe design of claim 1 , wherein the inner die pad structure is spaced from about 100 to 800 μm above the lead finger inner portions, and the outer die pad structure is spaced from about 100 to 800 μm below the lead finger inner portions.

24. The leadframe design of claim 1 , wherein the inner die pad structure is spaced from about 100 to 500 μm above the lead linger inner portions, and the outer die pad structure is spaced from about 100 to 500 μm below the lead finger inner portions.

25. The leadframe design of claim 1 , wherein the inner die pad structure is spaced a distance above the lead finger inner portions; the outer die pad structure is spaced a distance below the lead finger inner portions; the first and second chips and the lead finger inner portions each have respective upper surfaces; the first chip connected to the lead finger inner portions by respective upper lead wires affixed to the upper surface of the first chip and the upper surfaces of the lead finger inner portions; and the second chip connected to the lead finger inner portions by respective lower lead wires affixed to the lower surface of the second chip and the lower structures of the lead finger inner portions.

26. The leadframe design of claim 1 , wherein the first and second chips are the same size.

27. The leadframe design of claim 1 , wherein the second chip is smaller than the first chip.

28. The leadframe design of claim 1 , wherein a heat sink structure is affixed to the first chip.

29. The leadframe design of claim 1 , wherein a heat sink structure is affixed to the first chip, and a heat conductive layer is affixed to the heat sink structure.

30. The leadframe design of claim 1 , wherein the inner die pad structure is positioned within an area encircled by bond pads.

31. A leadframe design, comprising:

an inner die pad structure lying in a first plane;

an outer package surrounding at least the inner die pad structure and the inner tie bars; the outer die pad structure being supported by outer tie bars; the outer package having outer walls; and

lead fingers extending through the outer package outer walls; the lead fingers including an inner portions extending into the outer package proximate die inner and outer die pad structures; the inner portions of the lead fingers lying in a third plane; wherein at least one of the inner die pad structure first plane and the outer die pad structure second plane lie outside of the lead finger inner portions third plane and wherein a first chip is affixed to the inner die pad structure and a second chip is affixed to the outer die pad structure, and wherein the inner die pad structure is spaced a distance below the lead finger inner portions and the outer die pad structure is coplanar with the lead finger inner portions.

32. The leadframe design of claim 31 , wherein the first chip is affixed to the inner die pad structure by resin and the second chip is affixed to the outer die pad structure by resin.

33. The leadframe design of claim 31 , wherein the inner die pad structure is rectangular in shape.

34. The leadframe design of claim 31 , wherein the inner die pad structure is spaced from about 100 to 1000 μm below the lead finger inner portions.

35. The leadframe design of claim 31 , wherein the inner die pad structure is spaced from about 200 to 500 μm below the lead finger inner portions.

36. The leadframe design of claim 31 , wherein the inner die pad structure is spaced a distance below the lead finger inner portions; the outer die pad structure is coplanar with the lead finger inner portions; the first and second chips and the lead finger inner portions each have respective upper surfaces; the first chip connected to the lead finger inner portions by respective lower lead wires affixed to the upper surface of the first chip and the upper surfaces of the lead finger inner portions; and the second chip connected to the lead finger inner portions by respective upper lead wires affixed to the upper surface of the second chip and the upper structures of the lead finger inner portions.

37. The leadframe design of claim 31 , wherein the inner die pad structure is positioned within an area encircled by bond pads.

38. A leadframe design, comprising:

an inner die pad structure lying in a first plane;

an outer package surrounding at least the inner die pad structure and the inner tie bars; the outer die pad structure being supported by outer tie bars; the outer package having outer walls; and

lead fingers extending through the outer package outer walls; the lead fingers including an inner portions extending into the outer package proximate the inner and outer die pad structures; the inner portions of the lead fingers lying in a third plane; wherein at least one of the inner die pad structure first plane and the outer die pad structure second plane lie outside of the lead finger inner portions third plane and wherein a first chip is affixed to the inner die pad structure and a second chip is affixed to the outer die pad structure, and wherein the outer die pad structure is spaced a first distance below the lead finger inner portions and the inner die pad structure is spaced a second distance below the lead finger inner portions; the second distance being greater than the first distance.

39. The leadframe design of claim 38 , wherein the first chip is affixed to the inner die pad structure by resin and the second chip is affixed to the outer die pad structure by resin.

40. The leadframe design of claim 38 , wherein the inner die pad structure is rectangular in shape.

41. The leadframe design of claim 38 , wherein the outer die pad structure is spaced from about 300 to 1.000 μm below the lead finger inner portions and the inner die pad structure is spaced from about 350 to 800 μm below the lead finger inner portions.

42. The leadframe design of claim 38 , wherein the outer die pad structure is spaced from about 150 to 500 μm below the lead finger inner portions and the inner die pad structure is spaced from about 150 to 300 μm below the lead finger inner portions.

43. The leadframe design of claim 38 , wherein the outer die pad structure is spaced a first distance below the lead finger inner portions and the inner die pad structure is spaced a second distance below the lead finger inner portions; the second distance being greater than the first distance; the first and second chips and the lead finger inner portions each have respective upper surfaces; the first chip connected to the lead finger inner portions by respective lower lead wires affixed to the upper surface of the first chip and the upper surfaces of the lead finger inner portions; and the second chip connected to the lead finger inner portions by respective upper lead wires affixed to the upper surface of the second chip and the upper surfaces of the lead finger inner portions.

44. The leadframe design of claim 38 , wherein the inner die pad structure is positioned within an area encircled by bond pads.

45. A leadframe design, comprising:

an inner die pad structure lying in a first plane;

an outer package surrounding at least the inner die pad structure and the inner tie bars; the outer die pad structure being supported by outer tie bars; the outer package having outer walls; and

46. The leadframe design of claim 45 , wherein the first chip is affixed to the inner die pad structure by resin and the second chip is affixed to the outer die pad structure by resin.

47. The leadframe design of claim 45 , wherein the inner die pad structure is rectangular in shape.

48. The leadframe design of claim 45 , wherein the outer die pad structure is spaced from about 100 to 800 μm above the lead finger inner portions.

49. The leadframe design of claim 45 , wherein the outer die pad structure is spaced from about 200 to 500 μm above the lead finger inner portions.

50. The leadframe design of claim 45 , wherein the outer die pad structure is spaced a distance above the lead finger inner portions and the inner die pad structure is coplanar with the lead finger inner portions; the first and second chips and the lead finger inner portions each have respective upper surfaces; the first chip connected to the lead finger inner portions by respective lower lead wires affixed to the upper surface of the first chip and the upper surfaces of the lead finger inner portions; and the second chip connected to the lead finger inner portions by respective upper lead wires affixed to the upper surface of the second chip and the upper surfaces of the lead finger inner portions.

51. The leadframe design of claim 45 , wherein the inner die pad structure is positioned within an area encircled by bond pads.

52. A leadframe design, comprising:

an inner die pad structure lying in a first plane;

an outer package surrounding at least the inner die pad structure and the inner tie bars; the outer die pad structure being supported by outer tie bars; the outer package having outer walls; and

53. The leadframe design of claim 52 , wherein the first chip is affixed to the inner die pad structure by resin and the second chip is affixed to the outer die pad structure by resin.

54. The leadframe design of claim 52 , wherein the inner die pad structure is rectangular in shape.

55. The leadframe design of claim 52 , wherein the outer die pad structure is spaced above the lead finger inner portions and the inner die pad structure is spaced below the lead finger inner portions.

56. The leadframe design of claim 52 , wherein the outer die pad structure is spaced from about 100 to 800 μm above the lead finger inner portions and the inner die pad structure is spaced from about 100 to 800 μm below the lead finger inner portions.

57. The leadframe design of claim 52 , wherein the outer die pad structure is spaced from about 200 to 500 μm above the lead finger inner portions and the inner die pad structure is spaced from about 200 to 500 μm below the lead finger inner portions.

58. The leadframe design of claim 52 , wherein the outer die pad structure is spaced above the lead finger inner portions and the inner die pad structure is spaced below the lead finger inner portions; the first and second chips and the lead finger inner portions each have respective upper surfaces; the first chip connected to the lead finger inner portions by respective lower lead wires affixed to the upper surface of the first chip and the upper surfaces of the lead finger inner portions; and the second chip connected to the lead finger inner portions by respective upper load wires affixed to the upper surface of the second chip and the upper surfaces of the lead finger inner portions.

59. The leadframe design of claim 52 , wherein the inner die pad structure is positioned within an area encircled by bond pads.

60. A leadframe design, comprising:

an inner die pad structure lying in a first plane;

an outer package surrounding at least the inner die pad structure and the inner tie bars; the outer die pad structure being supported by outer tie bars; the outer package having outer walls; and

wherein at least one of the inner die pad structure first plane and the outer die pad structure second plane lie outside of the lead finger inner portions third plane and wherein a first chip is affixed to the inner die pad structure and a second chip is affixed to the outer die pad structure, and wherein the outer die pad structure is spaced above the lead finger inner portions and the inner die pad structure is spaced below the lead finger inner portions; the first and second chips and the lead finger inner portions each have respective upper and lower surfaces the first chip connected to the lead finger inner portions by respective lower lead wires affixed to the lower surface of the first chip and the lower surfaces of the lead finger inner portions; and the second chip connected to the lead finger inner portions by respective upper lead wires affixed to the upper surface of the second chip and the upper surfaces or the lead finger inner portions.

61. The leadframe design of claim 60 , wherein the first chip is affixed to the inner die pad structure by resin and the second chip is affixed to the outer die pad structure by resin.

62. The leadframe design of claim 60 , wherein the inner die pad structure is rectangular in shape.

63. The leadframe design of claim 60 , wherein the inner die pad structure is positioned within an area encircled by bond pads.

64. A leadframe design, comprising:

an inner die pad structure lying in a first plane;

an outer package surrounding at least the inner die pad structure and the inner tie bars; the outer die pad structure being supported by outer tie bars; the outer package having outer walls; and

lead fingers extending through the outer package outer walls; the lead 10 fingers including an inner portions extending into the outer package proximate the inner and outer die pad structures; the inner portions of the lead fingers lying in a third plane;

65. The leadframe design of claim 64 , wherein the first chip is affixed to the inner die pad structure by resin and the second chip is affixed to the outer die pad structure by resin.

66. The leadframe design of claim 64 , wherein the inner die pad structure is rectangular in shape.

67. The leadframe design of claim 64 , wherein the inner die pad structure is spaced from about 100 to 800 μm above the lead finger inner portions, and the outer die pad structure is spaced from about 100 to 800 μm below the lead finger inner portions.

68. The leadframe design of claim 64 , wherein the inner die pad structure is spaced from about 100 to 500 μm above the lead finger inner portions, and the outer die pad structure is spaced from about 100 to 500 μm below the lead finger inner portions.

69. The leadframe design of claim 64 , wherein the first and second chips and the lead finger inner portions each have respective upper surfaces; the first chip connected to the lead finger inner portions by respective upper lead wires affixed to the upper surface of the first chip and the upper surfaces of the lead finger inner portions; and the second chip connected to the lead finger inner portions by respective lower lead wires affixed to the lower surface of the second chip and the lower structures of the lead finger inner portions.

70. The leadframe design of claim 64 , wherein the first and second chips are the same size.

71. The leadframe design of claim 64 , wherein the inner die pad structure is positioned within an area encircled by bond pads.

72. A leadframe design, comprising:

an inner die pad structure lying in a first plane;

an outer package surrounding at least the inner die pad structure and the inner tie bars; the outer die pad structure being supported by outer tie bars; the outer package having outer wails; and

wherein at least one of the inner die pad structure first plane and the outer die pad structure second plane lie outside of the lead finger inner portions third plane and wherein a first chip is affixed to the inner die pad structure and a second chip is affixed to the outer die pad structure, and wherein the outer die pad structure is spaced above the lead finger inner portions and the inner die pad structure is spaced below the lead finger inner portions; the inner die pad structure, the first and second chips and the lead finger inner portions each have respective upper and lower surfaces; the first chip connected to the lead finger inner portions by respective lower lead wires affixed to the upper surface of the first chip and the upper surfaces of the lead finger inner portions; the second chip connected to the lead finger inner portions by respective upper lead wires affixed to the upper surface of the second chip and the upper surfaces of the lead finger inner portions; and the inner die pad structure connected to the lead finger inner portions by respective grounding lead wires affixed to the upper surface of the inner die pad structure and the upper surfaces of the lead finger inner portions.

73. The leadframe design of claim 72 , wherein the first chip is affixed to the inner die pad structure by resin and the second chip is affixed to the outer die pad structure by resin.

74. The leadframe design of claim 72 , wherein the inner die pad structure is rectangular in shape.

75. The leadframe design of claim 72 , wherein the second chip is smaller than the first chip.

76. The leadframe design of claim 72 , wherein the inner die pad structure is positioned within an area encircled by bond pads.

77. A method of forming a leadframe design, comprising;

providing an inner die pad structure lying in a first plane;

providing an outer die pad structure lying in a second plane spaced apart from the inner die pad structure first plane and connected to the inner die pad by inner tie bars, the outer die pad structure is ring shaped and surrounds the inner die pad structure;

providing an outer package surrounding at least the inner die pad structure and the inner tie bars; the outer die pad structure being supported by outer tie bars; the outer package having outer walls; and

providing lead fingers extending through the outer package outer walls; the lead fingers including an inner portions extending into the outer package proximate the inner and outer die pad structures; the inner portions of the lead fingers lying in a third plane;

wherein at least one of the inner die pad structure first plane and the outer die pad structure second plane lie outside of the lead finger inner portions third piano and wherein a first chip is affixed to the inner die pad structure and a second chip is affixed to the outer die pad structure.

78. A method of forming a leadframe design, comprising:

providing an inner die pad structure lying in a first plane;

79. A method of forming a leadframe design, comprising:

providing an inner die pad structure lying in a first plane;

providing lead fingers extending through the outer package outer wails; the lead fingers including an inner portions extending into the outer package proximate the inner and outer die pad structures; the inner portions of the lead fingers lying in a third plans;

80. A method of forming a leadframe design, comprising:

providing an inner die pad structure lying in a first plane;

81. A method of forming a leadframe design, comprising:

providing an inner die pad structure lying in a first plane;

82. A method of forming a leadframe design, comprising:

providing an inner die pad structure lying in a first plane;

wherein at least one of the inner die pad structure first plane and the outer die pad structure second plane lie outside of the lead finger inner portions third plane and wherein a first chip is affixed to the inner die pad structure and a second chip is affixed to the outer die pad structure, and wherein the outer die pad structure is spaced above the lead finger inner portions and the inner die pad structure is spaced below the lead finger inner portions; the first and second chips and the lead finger inner portions each have respective upper and lower surfaces; the first chip connected to the lead finger inner portions by respective lower lead wires affixed to the lower surface of the first chip and the lower surfaces of the lead finger inner portions; and the second chip connected to the lead finger inner portions by respective upper lead wires affixed to the upper surface of the second chip and the upper surfaces of the lead finger inner portions.

83. A method of forming a leadframe design, comprising:

providing an inner die pad structure lying in a first plane;

84. A method of forming a leadframe design, comprising:

providing an inner die pad structure lying in a first plane;

providing an outer package surrounding at least the inner die pad structure and the inner tie bars, the outer die pad structure being supported by outer tie bars; the outer package having outer walls; and

wherein at least one of the inner die pad structure first plane and the outer die pad structure second plane lie outside of the lead finger inner portions third plane and wherein a first chip is affixed to the inner die pad structure and a second chip is affixed to the outer die pad structure, and wherein the outer die pad structure is spaced above the lead finger inner portions and the inner die pad structure is spaced below the lead finger inner portions; the inner die pad structure, the first and second chips and the lead finger inner portions each have respective upper and lower surfaces; the first chip connected to the lead finger inner portions by respective lower lead wires affixed to the upper surface of the first chip and the upper surfaces of the lead finger inner portions; the second chip connected to the lead finger inner portions by respective upper lead wires affixed to the upper surface of the second chip and the upper surfaces of the lead finger inner portions; and the inner die pad structure connected to the lead finger inner portions by respective grounding lead wires affixed to the upper surface of the inner die pad structure and the upper surfaces of the lead finger inner portions.

Assignments (5)

CORRECTIVE ASSIGNMENT TO CORRECT THE ASSIGNEE'S NAME PREVIOUSLY RECORDED AT REEL: 038378 FRAME: 0400. ASSIGNOR(S) HEREBY CONFIRMS THE ASSIGNMENT. Recorded Sep 5, 2023

From: STATS CHIPPAC LTD.

To: STATS CHIPPAC PTE. LTD.

Reel/Frame 064806/0593 →

RELEASE OF SECURITY INTEREST Recorded Jun 16, 2020

From: CITICORP INTERNATIONAL LIMITED, AS COMMON SECURITY AGENT

To: STATS CHIPPAC, INC.; STATS CHIPPAC PTE. LTD. FORMERLY KNOWN AS STATS CHIPPAC LTD.

Reel/Frame 052950/0497 →

CHANGE OF NAME Recorded Apr 7, 2016

From: STATS CHIPPAC LTD.

To: STATS CHIPPAC PTE. LTE.

Reel/Frame 038378/0400 →

CHANGE OF NAME Recorded Aug 6, 2015