IC package with dual heat spreaders

• US 6,326,687 B1
• Filed: 09/01/1998
• Issued: 12/04/2001
• Est. Priority Date: 09/01/1998
• Status: Expired due to Fees

• Current Assignee: Micron Technology, Inc.
• Original Assignee: Micron Technology, Inc.
• Inventors: Corisis, David J.
• Primary Examiner(s): Chaudhuri, Olik
• Assistant Examiner(s): Chambliss, Alonzo
• Application Number:
  US09/145,339
• Time in Patent Office: 1,190 Days
• Field of Search: 438/122, 438/107, 257/712, 257/713, 257/276, 257/719, 257/723, 257/675, 257/686, 257/730, 257/685, 257/687, 257/659, 257/660, 257/704-708, 257/729, 257/787, 257/796, 298/30, 298/56, 361/709, 361/716, 361/711
• US Class Current: 257/713
• CPC Class Codes: H01L 2224/05599 Material
• CPC Class Codes: H01L 2224/45015 being circular
• CPC Class Codes: H01L 2224/45099 Material
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48095 Kinked
• CPC Class Codes: H01L 2224/48247 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/85399 Material
• CPC Class Codes: H01L 23/4334 Auxiliary members in encapsulations H01L23/49568 takes precedence
• CPC Class Codes: H01L 23/49568 specifically adapted to facilitate heat dissipation
• CPC Class Codes: H01L 23/552 Protection against radiation, e.g. light or electromagnetic waves
• CPC Class Codes: H01L 23/585 comprising conductive layers or plates or strips or rods or rings H01L23/60, H01L23/62, H01L23/64, H01L23/66 take precedence
• CPC Class Codes: H01L 24/48 of an individual wire 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 2924/00012 Relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/01079 Gold [Au]
• CPC Class Codes: H01L 2924/14 Integrated circuits
• CPC Class Codes: H01L 2924/181 Encapsulation
• CPC Class Codes: H01L 2924/207 Diameter ranges
• CPC Class Codes: H01L 2924/30107 Inductance
• CPC Class Codes: H01L 2924/3025 : Electromagnetic shielding
• CPC Class Codes: Y10T 29/49121 : Beam lead frame or beam lead device
• CPC Class Codes: Y10T 29/49126 : Assembling bases
• CPC Class Codes: Y10T 29/4913 : Assembling to base an electrical component, e.g., capacitor, etc.
• CPC Class Codes: Y10T 29/49146 : with encapsulating, e.g., potting, etc.
• CPC Class Codes: Y10T 29/49147 : Assembling terminal to base
• CPC Class Codes: Y10T 29/49169 : Assembling electrical component directly to terminal or elongated conductor
• CPC Class Codes: Y10T 29/49171 : with encapsulating
• CPC Class Codes: Y10T 29/49172 : by molding of insulating material
• CPC Class Codes: Y10T 29/49174 : Assembling terminal to elongated conductor

Abstract

An integrated circuit device has a heat spreader attached to each of the major outer encapsulant surfaces. One or both of the heat spreaders has a pair of end posts configured for insertion into through-holes in a substrate to position and support the device during and following the outer lead solder reflow step at board assembly. The heat spreaders provide high heat dissipation and EMR shielding, and may be connected to the substrate ground to become ground planes.

Claims

1. A semiconductor device package, comprising:

a semiconductor die having electrical leads connected thereto, said semiconductor die encapsulated in a material forming a package, said package having opposing major external surfaces and having a package edge connecting said opposing major external surfaces and a portion of the electrical leads connected to said semiconductor die extending from said package ends, lead ends of said portion of electrical leads being configured for connection to a substrate, said package configured with register apparatus comprising a recess in at least one peripheral edge of said package, said recess extending to each of said opposing major external surfaces; and

two heat spreaders, each of the two heat spreaders contacting at least a portion of said substrate, said heat spreaders having a portion thereof attached to a portion of one of said opposing major external surfaces of said semiconductor die, thereby containing said semiconductor die between a portion of said heat spreaders, said heat spreaders configured to provide essentially a sole structural support for at least one of said electrical leads, said heat spreaders positioned so as to provide an opening between distal end portions of said heat spreaders, said heat spreaders comprising register apparatus on at least one peripheral edge of said heat spreaders for alignment with the register apparatus of said package.

2. The semiconductor device package of claim 1, wherein said electrical leads are configured for vertical mounting of said semiconductor die on said substrate, and at least one of said heat spreaders has at least one through-hole post extending outwardly beyond said lead ends for connection to said substrate.

3. The semiconductor device package of claim 2, wherein one of said heat spreaders has a through-hole post proximate each end of said semiconductor die for connection to said substrate, said substrate having apertures therein.

4. The semiconductor device package of claim 2, wherein a first heat spreader has at least one post proximate a first end of said semiconductor die, and a second heat spreader has at least one post proximate a second end of said semiconductor die.

5. The semiconductor device package of claim 1, wherein each of said heat spreaders substantially covers the attached portion of one of said opposing major external surfaces of said semiconductor die.

6. The semiconductor device package of claim 1, wherein at least one of said heat spreaders is configured for connection to a ground conductor on said substrate.

7. The semiconductor device package of claim 1, wherein said semiconductor die comprises a vertical mount plastic-encapsulated package.

8. The semiconductor device package of claim 1, wherein said register apparatus on said at least one peripheral edge of each of said heat spreaders are configured for machine positionin and attachment of each that spreader on one of said opposing major external surfaces of said package.

9. The semiconductor device package of claim 8, wherein said register apparatus on said at least one peripheral edge of said heat spreaders comprises cutout portion of each of said heat spreaders.

10. The semiconductor device package of claim 1, wherein said heat spreaders are attached to said package with an adhesive.

11. The semiconductor device package of claim 1, wherein said heat spreaders are attached to said package with an adhesive-coated tape.

12. The semiconductor device package of claim 1, wherein said heat spreaders comprise plates, said plates including metal, ceramic material, and plastic material.

13. The semiconductor device package of claim 1, further comprising:

a second layer of material encapsulating said heat spreaders within said package.

14. A semiconductor device, comprising:

a semiconductor die encapsulated in material forming a package having two opposing major external surfaces and having a package edge connecting said major external surfaces and electrical leads extending therefrom, wherein lead ends of the electrical leaeds are for attachment to a substrate, said package configured with register apparatus comprising a recess in at least one peripheral edge of said package, said recess extending to each of said opposing major external surfaces; and

two heat spreaders, each heat spreader having a surface attached to one of said major external surfaces of said package, said each heat spreader contacting at least a portion of said substrate, said package sandwiched between said heat spreaders, said heat spreaders configured to provide essentially the sole structural support for at least one of said electrical leads, said heat spreaders positioned so as to provide an opening between distal end portions of said heat spreaders, said heat spreaders comprising register apparatus on at least one peripheral edge of said heat spreaders for alignment with the register apparatus of said package.

15. The semiconductor device of claim 14, wherein said electrical leads are configured for vertical mounting of said semiconductor die on said substrate, and at least one of said heat spreaders has at least one post extending beyond said lead ends for attachment to said substrate.

16. The semiconductor device of claim 15, wherein one of said heat spreaders has a post proximate each end of said semiconductor die.

17. The semiconductor device of claim 15, wherein a first heat spreader of said heat spreaders has at least one post proximate a first end of said semiconductor die, and a second heat spreader of said heat spreaders has at least one post proximate a second, opposite end of said semiconductor die.

18. The semiconductor device of claim 14, wherein each of said heat spreaders substantially covers said one of the attached two opposing major external surfaces of said package.

19. The semiconductor device of claim 14, wherein at least one of said heat spreaders is configured for attachment to a conductor on said substrate.

20. The semiconductor device of claim 14, wherein said semiconductor device comprises a vertical mount plastic-encapsulated package.

21. The semiconductor device of claim 14, wherein said register apparatus on at least one peripheral edge of each of said heat spreaders are configured for machine positioning and attachment of each heat spreader on one of said two opposing major external surfaces.

22. The semiconductor device of claim 21, wherein said register apparatus comprises cutout portions of each of said heat spreaders.

23. The semiconductor device of claim 14, wherein said heat spreaders are attached to said package with an adhesive.

24. The semiconductor device of claim 14, wherein said heat spreaders are attached to said package with an adhesive-coated tape.

25. The semiconductor device of claim 14, wherein said heat spreaders comprise plates, said plates including metal, ceramic material, and plastic material.

26. The semiconductor device of claim 14, further comprising:

a second layer of material encapsulating said heat spreaders within said package.

27. A vertical mount semiconductor package, comprising:

a semiconductor die having opposed major surfaces and circuits formed on one of said opposed major surfaces;

a die support member attached to the other of said opposed major surfaces of said semiconductor die;

conductive outer leads along one edge of said semiconductor die between said opposed major surfaces for attachment to a substrate;

conductive lead members connecting said circuits to said conductor outer leads;

a material encapsulating portions of said semiconductor die, said die support member, and said conductive lead members, said material forming a package, said package configured with register apparatus comprising a recess in at least one peripheral edge of said package, said recess extending to each of said opposed major surfaces; and

thermally conductive plates comprising heat spreaders attached to said material, each thermally conductive plate contacting at least a portion of said substrate, said each thermally conductive plate covering a portion of said material encapsulating said portion of said semiconductor die and configured to provide essentially a sole structural support for at least one of said conductive outer leads, said heat spreaders positioned so as to provide an opening between distal end portions of said heat spreaders, said heat spreaders comprising register apparatus on at least one peripheral edge of each of said heat spreaders for alignment with the register apparatus of said package and for machine positioning and attachment of said heat spreaders on said opposed major surfaces of said package.

28. The vertical mount semiconductor package of claim 27, wherein said heat spreaders are secured to said material encapsulating said portions of said semiconductor die.

29. The vertical mount semiconductor package of claim 27, wherein said heat spreaders are adhesively secured to said material encapsulating said portions of said semiconductor die.

30. The vertical mount semiconductor package of claim 27, wherein said heat spreaders are secured to said material encapsulating said portions of said semiconductor die by an adhesive-coated tape.

31. The vertical mount semiconductor package of claim 27, further comprising:

a second layer of material covering a portion of said heat spreaders.

32. A vertical mount semiconductor package, comprising:

a semiconductor die having opposed major surfaces and circuits formed on one of said opposed major surfaces;

a die support member attached to the other of said opposed major surfaces of said semiconductor die;

conductive outer leads along one edge of said semiconductor die between said opposed major surfaces for attachment to a substrate;

conductive lead members connecting said circuits to said conductive outer leads;

a material encapsulating said semiconductor die, said die support member and said conductive lead members, said material forming a package, said package configured with register apparatus comprising a recess in at least one peripheral edge of said package, said recess extending to each of said opposed major external surfaces; and

thermally conductive plates comprising heat spreaders attached to said material encapsulating said semiconductor die and substantially covering said opposed major surfaces of said semiconductor die, said heat spreaders configured to provide essentially a sole structural support for at least one of said conductive outer leads, said heat spreaders positioned so as to provide an opening between distal end portions of said heat spreaders, said heat spreaders comprising register apparatus on at least one peripheral edge of each of said heat spreaders for alignment with the register apparatus of said package.

33. The vertical mount semiconductor package of claim 32, wherein said heat spreaders are secured to said material encapsulating said semiconductor die.

34. The vertical mount semiconductor package of claim 32, wherein said heat spreaders are secured to said material encapsulating said semiconductor die by an adhesive material.

35. The vertical mount semiconductor package of claim 32, wherein said heat spreaders are secured to said material encapsulating said semiconductor die by an adhesive-coated tape.

36. The vertical mount semiconductor package of claim 32, further comprising:

a second layer of material securing said heat spreaders to said material encapsulating said semiconductor die.

37. A heat spreader apparatus for an encapsulated semiconductor device having a row of exterior leads, a peripheral edge and at least two opposed major surfaces, the encapsulated semiconductor device having a register apparatus in the peripheral edge thereof, comprising:

a plate forming a first heat spreader for covering a portion of one of said at least two opposed major surfaces of said encapsulated semiconductor device, said first heat spreader having a lead edge proximate to said row of exterior leads having at least one post projecting therefrom for securing said encapsulated semiconductor device to a substrate having at least one circuit thereon said firs theat spreader comprising register apparatus on at least one peripheral edge thereof for accurate mounting to one of said at least two opposed major surfaces;

another plate forming heat spreader for covering a portion of a second one of said at least two opposed major surfaces of said encapsulated semiconductor device, said second heat spreader having a lead edge proximate to said row of exterior leads having at least one post projecting therefrom for securing said semiconductor device to said substrate having said at least one circuit thereon, said second heat spreader comprising register apparatus on at least one peripheral edge thereof for accurate mounting to second one of said at least two opposed major surfaces, each of said register apparatus of said first heat spreader and said second heat spreader aligned with the register apparatus of the encapsulated semiconductor device to form a recess extending into the at least two opposed major surfaces and each of said first heat spreader and said second heat spreader; and

wherein said heat spreaders are configured to provide essentially a sole structural support for at least one of said row of exterior leads, said heat spreaders are positioned so as to provide an opening between distal end portions of said heat spreaders, and said at least one post align said row of exterior leads with said at least one circuit on said substrate.

38. The heat spreader apparatus of claim 37, wherein said first heat spreader and said second heat spreader are identical in shape for inverse attachment to said at least two opposed major surfaces.

39. The heat spreader apparatus of claim 40, wherein said at least one post is positioned adjacent one end on each of said first heat spreader and said second heat spreader.

40. The heat spreader apparatus of claim 38, wherein said first heat spreader has two posts projecting therefrom and said second heat spreader has no through-hole posts.

41. The heat spreader apparatus of claim 37, wherein said plates are comprised of metal, a metal filled polymer material, and a ceramic material.

42. The heat spreader apparatus of claim 37, wherein said register apparatus on said at least one peripheral edge of each of said first heat spreader and said second heat spreader are configured for machine positioning and attachment to one of said at least two opposed major surfaces.

46. The heat spreader apparatus of claim 42, wherein each of said two heat spreaders is similar in shape for inverse attachment to one of said two opposed major surfaces.

43. A heat spreader apparatus for an encapsulated semiconductor device having a row of exterior leads, a peripheral edge and two opposed major surfaces, the encapsulated semiconductor device having a register apparatus in the peripheral edge thereof, comprising:

a plate of heat conductive material cut to form two heat spreaders for substantially covering each of said two opposed major surfaces of said encapsulated semiconductor device, each of said heat spreaders having a lead edge proximate to said row of exterior leads, said two heat spreaders having at least two posts projecting therefrom for attachment to a substrate and aligning said row of exterior leads with respect to said substrate, said two heat spreaders configured to provide essentially the sole structural support for at least one of said row of exterior leads, said heat spreaders comprising register apparatus on at least one peripheral edge thereof for accurate mounting to said two opposed major surfaces, each of said register apparatus of said heat spreaders aligned with the register apparatus of the encapsulated semiconductor device to form a recess extending into the two opposed major surfaces and each of said heat spreaders; and

wherein said two heat spreaders are positioned so as to provide an opening between distal end portions of said two heat spreaders.

44. The heat spreader apparatus of claim 43, wherein each of said two heat spreaders has two posts projecting therefrom.

45. The heat spreader apparatus of claim 43, wherein each of said two heat spreaders has one post projecting therefrom.

47. The heat spreader apparatus of claim 43, wherein one of said at least two posts is positioned adjacent an end of said two heat spreaders.

48. The heat spreader apparatus of claim 43, wherein one of said heat spreaders has two posts projecting therefrom and the other of said heat spreaders has no through-hole posts.

49. The heat spreader apparatus of claim 45, wherein said plate comprises one of metal, metal filled polymer material, and ceramic material.

50. The heat spreader apparatus of claim 45, wherein said register apparatus formed on each of said two heat spreaders are configured for machine positioning and attachment of said two heat spreaders to said two opposed major surfaces.

51. A method for forming a semiconductor device comprising:

providing a semiconductor die connected to exterior leads extending therefrom;

encapsulating said semiconductor die in a material to form a package having opposing major surfaces, a peripheral edge having a register apparatus therein and a portion of said exterior leads connected to said semiconductor die projecting therefrom;

forming a pair of heat spreaders, said pair of heat spreaders having at least two posts extending therefrom for contacting at least a portion of a substrate, each heat spreader of said pair of heat spreaders configured to cover a portion of one of said opposing major surfaces, said heat spreaders providing essentialy a sole structural support for at least one of said exterior leads, said heat spreaders comprising register apparatus on at least one peripheral edge thereof for accurate mounting to said opposing major surfaces;

attaching said pair of heat spreaders to said opposing major surfaces of said package formed by said material encapsulating said semiconductor die by aligning each of said register apparatus of said heat spreaders with the register apparatus of said package to form a recess extending into said opposing major surfaces and each of said heat spreaders; and

positioning said heat spreaders so as to provide an opening between distal end portions of said heat spreaders.

52. The method of claim 51, further comprising:

performing another encapsulation step to form a final package having portions of said pair of heat spreaders therein, said exterior leads and portions of said at least two posts extending from said final package.

53. The method of claim 51, further comprising:

providing a substrate having at least one electrical substrate lead formed thereon; and

forming substrate areas in said substrate for insertion of said at least two posts therein to align said exterior leads with said at least one electrical substrate lead.

54. The method of claim 53, further comprising:

inserting said at least two posts into said substrate areas; and

connecting said exterior leads to said at least one electrical substrate lead.

55. The method of claim 54, further comprising:

securing said at least two posts to said substrate areas with adhesive material.

56. The method of claim 51, further comprising:

electrically connecting at least one of said pair of heat spreaders to a ground bus.

57. The method of claim 56, wherein a post of said pair of heat spreaders is connected to said ground bus.

58. A method for forming a semiconductor device comprising:

forming a semiconductor die having exterior leads connected thereto;

encapsulating said semiconductor die with a material to form a package having two opposing major surfaces, a peripheral edge having a register apparatus therein and a portion of said exterior leads projecting therefrom;

forming a pair of heat spreaders, said pair of heat spreaders having at least two through-hole posts extending therefrom for contacting at least a portion of a substrate, each heat spreader of said pair of heat spreaders configured to substantially cover one of said opposing major surfaces of said package, said heat spreaders comprising register apparatus on at least on peripheral edge thereof for accurate mounting to said two opposing major surfaces;

attaching said heat spreaders to said opposing major surfaces of said package so as to provide essentially the sole structural support for at least one of said exterior leads, said attaching comprising aligning each of said register apparatus of said heat spreaders with said register apparatus of said package to form a recess extending into said two opposing major surfaces and each of said heat spreaders; and

positioning said heat spreaders so as to provide an opening between distal end portions of said heat spreaders.

59. The method of claim 58, further comprising:

encapsulating portions of said pair of heat spreaders and portions of said package forming a final package, said exterior leads and through-hole posts extending from said final package.

60. The method of claim 58, further comprising:

providing a substrate having a plurality of electrical leads formed thereon; and

forming through-holes in said substrate for insertion of said through-hole posts therein for aligning said exterior leads with said plurality of electrical substrate leads.

61. The method of claim 60, further comprising:

inserting said through-hole posts into said through-holes and attaching said exterior leads to said plurality of electrical substrate leads.

62. The method of claim 60, further comprising:

securing said through-hole posts in said through-holes with adhesive material.

63. The method of claim 58, further comprising:

conductively attaching at least one of said pair of heat spreaders to a ground bus.

64. The method of claim 60, further comprising:

connecting said through-hole post of said pair of heat spreaders to a ground bus located on said substrate.

65. A semiconductor device package, comprising:

a semiconductor die having electrical leads connected thereto, said semiconductor die encapsulated in a material forming a package, said package having opposing major external surfaces and having a package edge connecting said opposing major external surfaces and a portion of the electrical leads connected to said semiconductor die extending from said package edge, lead ends of said portion of electrical leads being configured for connection to a substrate, said package configured with register apparatus comprising a recess in at least one peripheral edge of said package, said recess extending to each of said opposing major external surfaces;

two heat spreaders, each heat spreader contacting at least a portion of said substrate and having a portion of said heat spreader attached to a portion of one of said opposing major external surfaces of said semiconductor die, thereby containing said semiconductor die between a portion of said heat spreaders, said two heat spreaders configured to provide essentially a sole structural support for at least one of said electrical leads, said heat spreaders positioned so as to leave an opening between distal end portions of said heat spreaders; and

register apparatus on a peripheral edge of said heat spreaders for machine positioning and attachment of each heat spreader on one of said opposing major external surfaces of said package so that said register apparatus of said heat spreaders is alignable with said register apparatus of said package.

66. The semiconductor device package of claim 65, wherein said electrical leads are configured for vertical mounting of said semiconductor die on said substrate, and at least one of said heat spreaders has at least one through-hole post extending outwardly beyond said lead ends for connection to said substrate.

67. The semiconductor device package of claim 66, wherein one of said heat spreaders has a through-hole post proximate each end of said device for connection to said substrate, said substrate having apertures therein.

68. The semiconductor device package of claim 66, wherein a first heat spreader has at least one post proximate a first end of said semiconductor die, and a second heat spreader has at least one post proximate a second, opposite end of said semiconductor die.

69. The semiconductor device package of claim 65, wherein each of said heat spreaders substantially covers the attached portion of one of said major external surfaces of said semiconductor die.

70. The semiconductor device package of claim 67, wherein each of said heat spreaders substantially covers the attached portion of one of said opposing major external surfaces of said semiconductor die.

71. The semiconductor device package of claim 65, wherein said semiconductor die comprises a vertical mount plastic-encapsulated package.

72. The semiconductor device package of claim 65, wherein said register apparatus on a peripheral edge of each of said heat spreaders comprises cutout portions of each of said heat spreaders.

73. The semiconductor device package of claim 65, wherein said heat spreaders are attached to said package with an adhesive.

74. The semiconductor device package of claim 65, wherein said heat spreaders are attached to said package with an adhesive-coated tape.

75. The semiconductor device package of claim 65, wherein said heat spreaders comprise plates, said plates including metal, ceramic material, and plastic material.

76. The semiconductor device package of claim 65, further comprising:

a second layer of material encapsulating said heat spreaders within said package.

77. A method for forming a semiconductor device comprising:

forming a semiconductor die having exterior leads connected thereto;

encapsulating said semiconductor die with a material to form a package having two opposing major surfaces and a portion of said exterior leads projecting therefrom;

forming register apparatus on at least one peripheral edge of said package;

forming a pair of heat spreaders, said pair of heat spreaders having at least two through-hole posts extending therefrom, each heat spreader of said pair of heat spreaders configured to substantially cover one of said opposing major surfaces of said package;

forming register apparatus on said each heat spreader of said pair of heat spreaders, said register apparatus formed on at least one peripheral edge of said each heat spreader for machine positioning and attachment of said each heat spreader on one of said opposing major surfaces of said package;

attaching said heat spreaders to said opposing major surfaces of said package so as to provide essentially a sole structural support for at least one of said exterior leads, wherein said attaching comprises aligning each of said register apparatus of said heat spreaders with said register apparatus of said package to form a recess extending into said two opposing major surfaces and each of said heat spreaders; and

positioning said heat spreaders so as to provide an opening between distal end portions of said heat spreaders.

78. The method of claim 77, wherein forming said register apparatus on said at least one peripheral edge of said heat spreader comprises cutout portions of said each heat spreader of said pair of heat spreaders.

79. The method of claim 77, further comprising:

encapsulating portions of said pair of heat spreaders and portions of said package forming a final package, said exterior leads and through-hole posts extending from said final package.

80. The method of claim 77, further comprising:

providing a substrate having a plurality of electrical substrate leads formed thereon; and

forming through-holes in said substrate for insertion of said through-hole posts therein for aligning said exterior leads with said plurality of electrical substrate leads.

81. The method of claim 80, further comprising:

inserting said through-hole posts into said through-holes and attaching said exterior leads to said plurality of electrical substrate leads.

82. The method of claim 80, further comprising:

securing said through-hole posts in said through-holes with adhesive material.

83. The method of claim 77, further comprising:

conductively attaching at least one of said pair of heat spreaders to a ground bus.

84. The method of claim 80, further comprising:

connecting a through-hole post of said pair of heat spreaders to a ground bus located on said substrate.

85. A semiconductor device package, comprising:

a semiconductor die having electrical lads connected thereto, said semiconductor die encapsulated in a maerial forming a package, said package having opposing major external surfaces and having four minor edge surfaces connecting said opposing major external surfaces, said package configured with register apparatus comprising a recess in at least one peripheral edge of said package, said recess extending to each of said opposing major external surfaces;

a portion of the electrical leads connected to said semiconductor die extending from one of said minor edge surfaces, lead ends of said portion of the electrical leads being configured for connection to a substrate;

two heat spreaders, each heat spreader having a portion thereof attached to a portion of one of said opposing major external surfaces of said semiconductor die thereby containing said semiconductor die between a portion of said heat spreaders, said two heat spreaders configured to provide essentially a sole structural support for at least one of said electrical leads, said two heat spreaders positioned so as to provide an opening between distal end portions of said heat spreaders, said heat spreaders comprising register apparatus on at least one peripheral edge of each of said heat spreaders for alignment with the register apparatus of said package; and

wherein said minor edge surfaces have no heat dissipating structures attached thereon.

86. The semiconductor device package of claim 85, wherein said electrical leads are configured for vertical mounting of said semiconductor die on said substrate, and at least one of said heat spreaders has at least one through-hole post extending outwardly beyond said lead ends for connection to said substrate.

87. The semiconductor device package of claim 86, wherein one of said heat spreaders has a through-hole post proximate each end of said semiconductor die for connection to said substrate, said substrate having apertures therein.

88. The semiconductor device package of claim 86, wherein a first heat spreader has at least one post proximate a first end of said semiconductor die, and a second heat spreader has at least one post proximate a second, opposite end of said semiconductor die.

89. The semiconductor device package of claim 85, wherein each of said heat spreaders substantially covers the attached portion of one of said opposing major external surfaces of said semiconductor die.

90. The semiconductor device package of claim 85, wherein at least one of said heat spreaders is configured for connection to a ground conductor on said substrate.

91. The semiconductor device package of claim 85, wherein said semiconductor die comprises a vertical mount plastic-encapsulated package.

92. The semiconductor device package of claim 85, wherein said register apparatus on at least one peripheral edge of each of said heat spreaders are configured for machine positioning and attachment of each heat spreader on one of said opposing major external surfaces of said package.

93. The semiconductor device package of claim 92, wherein said register apparatus on a peripheral edge of each of said heat spreaders comprises cutout portions of each of said heat spreaders.

94. The semiconductor device package of claim 85, wherein said heat spreaders are attached to said package with an adhesive.

95. The semiconductor device package of claim 85, wherein said heat spreaders are attached to said package with an adhesive-coated tape.

96. The semiconductor device package of claim 85, wherein said heat spreaders comprise plates, said plates including metal, ceramic material, and plastic material.

97. The semiconductor device package of claim 85, further comprising:

a second layer of material encapsulating said heat spreaders within said package.

98. A method for forming a semiconductor device comprising:

forming a semiconductor die having exterior leads connected thereto;

encapsulating said semiconductor die with a material to form a package having two opposing major surfaces and four minor edge surfaces connecting said opposing major surfaces, said package having a portion of said exterior leads projecting from one of said minor edge surfaces;

forming register apparatus on at least one peripheral edge of said package;

forming a pair of heat spreaders, said pair of heat spreaders having at least two through-hole posts extending therefrom for contacting at least a portion of a substrate, each heat spreader of said pair of heat spreaders configured to substantially cover one of said opposing major surfaces of said package;

forming register apparatus on each heat spreader of said pair of heat spreaders, said register apparatus formed on at least one peripheral edge of said each heat spreader;

attaching said heat spreaders to said opposing major surfaces of said package so as to provide essentially a sole structural support for at least one of said exterior leads, wherein said attaching comprises aligning each of said register apparatus of said heat spreaders with said register apparatus of said package to form a recess extending into said two opposing major surfaces and each of said heat spreaders;

positioning said heat spreaders so as to provide an opening between distal end portions of said heat spreaders; and

wherein said minor edge surfaces have no heat dissipating structures attached thereon.

99. The method of claim 98, further comprising:

encapsulating portions of said pair of heat spreaders and portions of said package forming a final package, said exterior leads and through-hole posts extending from said final package.

100. The method of claim 98, further comprising:

providing a substrate having a plurality of electrical substrate leads formed thereon; and

forming through-holes in said substrate for insertion of said through-hole posts therein for aligning said exterior leads with said plurality of electrical substrate leads.

101. The method of claim 100, further comprising:

inserting said through-hole posts into said through-holes and attaching said exterior leads to said plurality of electrical substrate leads.

102. The method of claim 100, further comprising:

securing said through-hole posts in said through-holes with adhesive material.

103. The method of claim 98, further comprising:

conductively attaching at least one of said pair of heat spreaders to a ground bus.

104. The method of claim 100, further comprising:

connecting a through-hole post of said pair of heat spreaders to a ground bus located on said substrate.

105. The method of claim 98, wherein said forming register apparatus on at least one peripheral edge of said each heat spreader of said pair of heat spreaders is for machine positioning and attachment of each heat spreader on one of said opposing major surfaces of said package.

106. The method of claim 105, wherein said forming register apparatus on at least one peripheral edge of said each heat spreader comprises cutout portions of each heat spreader of said pair of heat spreaders.