Semiconductor chip assembly with post/base heat spreader and signal post

• US 8,269,336 B2
• Filed: 12/19/2009
• Issued: 09/18/2012
• Est. Priority Date: 03/25/2008
• Status: Expired due to Fees

• Current Assignee: Bridge Semiconductor Corporation
• Original Assignee: Bridge Semiconductor Corporation
• Inventors: Lin, Charles W. C., Wang, Chia-Chung
• Primary Examiner(s): Kuo, Wensing
• Application Number:
  US12/642,795
• Publication Number:
  US 20100096662A1
• Time in Patent Office: 1,004 Days
• Field of Search: 257/693, 257/698, 257/700, 257/706, 257/713, 257/E23.102, 257/E33.075
• US Class Current: 257/698
• CPC Class Codes: H01L 21/486 Via connections through the substrate with or without pins
• CPC Class Codes: H01L 2224/32013 the layer connector being larger than the bonding area, e.g. bond pad
• CPC Class Codes: H01L 2224/32188 the layer connector connecting to a bonding area protruding from the surface of the item
• CPC Class Codes: H01L 2224/45144 Gold (Au) as principal constituent
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/73265 Layer and wire connectors
• CPC Class Codes: H01L 2224/85205 Ultrasonic bonding
• CPC Class Codes: H01L 23/3677 Wire-like or pin-like cooling fins or heat sinks
• 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 2924/01012 Magnesium [Mg]
• CPC Class Codes: H01L 2924/01019 Potassium [K]
• CPC Class Codes: H01L 2924/01046 Palladium [Pd]
• CPC Class Codes: H01L 2924/01078 Platinum [Pt]
• CPC Class Codes: H01L 2924/01079 Gold [Au]
• CPC Class Codes: H01L 2924/01087 Francium [Fr]
• CPC Class Codes: H01L 2924/181 Encapsulation
• CPC Class Codes: H01L 2924/19041 being a capacitor
• CPC Class Codes: H01L 33/486 adapted for surface mounting
• CPC Class Codes: H01L 33/642 : characterized by the shape
• CPC Class Codes: H05K 1/0204 : using means for thermal conduction connection in the thickness direction of the substrate H05K1/0207 takes precedence
• CPC Class Codes: H05K 2201/09054 : Raised area or protrusion of metal substrate
• CPC Class Codes: H05K 2201/10106 : Light emitting diode [LED]
• CPC Class Codes: H05K 2203/0369 : Etching selective parts of a metal substrate through part of its thickness, e.g. using etch resist
• CPC Class Codes: H05K 3/0061 : onto a metallic substrate, e.g. a heat sink heat sinks for electric apparatus H05K7/20

Abstract

A semiconductor chip assembly includes a semiconductor device, a heat spreader, a conductive trace and an adhesive. The semiconductor device is electrically connected to the conductive trace and thermally connected to the heat spreader. The heat spreader includes a thermal post and a base. The thermal post extends upwardly from the base into a first opening in the adhesive, and the base extends laterally from the thermal post. The conductive trace includes a pad, a terminal and a signal post. The signal post extends upwardly from the terminal into a second opening in the adhesive.

Claims

1. A semiconductor chip assembly, comprising:

a semiconductor device;

an adhesive that includes first and second openings;

a heat spreader that includes a thermal post and a base, wherein the thermal post is adjacent to and integral with the base and extends above the base in an upward direction, and the base extends below the thermal post in a downward direction opposite the upward direction, covers the thermal post in the downward direction and extends laterally from the thermal post in lateral directions orthogonal to the upward and downward directions; and

a conductive trace that includes a pad, a terminal and a signal post, wherein the signal post extends below the pad and above the terminal and an electrically conductive path between the pad and the terminal includes the signal post;

wherein the semiconductor device is mounted on the heat spreader, overlaps the thermal post, is electrically connected to the pad and thereby electrically connected to the terminal, and is thermally connected to the thermal post and thereby thermally connected to the base;

wherein the adhesive is mounted on and extends above the base, contacts the posts, the base and the terminal and extends laterally from the thermal post to or beyond the terminal;

wherein the pad extends above the posts and the adhesive and the terminal extends below the posts; and

wherein the thermal post extends into the first opening, the signal post extends into the second opening, the posts have the same thickness and are coplanar with one another between top and bottom surfaces of the pad and are the same metallic material as one another, and the base and the terminal have the same thickness and are coplanar with one another below the posts and are the same metallic material as one another.

2. The assembly of claim 1, wherein the semiconductor device is an LED package that includes an LED chip.

3. The assembly of claim 2, wherein the LED package is electrically connected to the pad using a first solder joint and is thermally connected to the heat spreader using a second solder joint.

4. The assembly of claim 1, wherein the semiconductor device is a semiconductor chip.

5. The assembly of claim 4, wherein the chip is electrically connected to the pad using a wire bond and is thermally connected to the heat spreader using a die attach.

6. The assembly of claim 1, wherein the adhesive is a solidified prepreg.

7. The assembly of claim 1, wherein the adhesive covers and surrounds the posts in the lateral directions.

8. The assembly of claim 1, wherein the adhesive conformally coats sidewalls of the posts.

9. The assembly of claim 1, wherein the adhesive is coplanar with tops and bottoms of the posts.

10. The assembly of claim 1, wherein the adhesive extends laterally from the thermal post beyond the terminal.

11. The assembly of claim 1, wherein the adhesive extends to peripheral edges of the assembly.

12. The assembly of claim 1, wherein the thermal post fills and is contained within the first opening, the signal post fills and is contained within the second opening and the posts are copper.

13. The assembly of claim 1, wherein the thermal post has a diameter that decreases as it extends upwardly from the base to its flat top, and the signal post has a diameter that decreases as it extends upwardly from the terminal to its flat top.

14. The assembly of claim 1, wherein the posts are coplanar with the adhesive between the top and bottom surfaces of the pad.

15. The assembly of claim 1, wherein the base covers the semiconductor device in the downward direction, supports the adhesive and is spaced from peripheral edges of the assembly.

16. The assembly of claim 1, wherein the terminal is adjacent to and integral with the signal post, covers the signal post in the downward direction and extends laterally from the signal post in the lateral directions.

17. The assembly of claim 1, wherein the heat spreader includes a cap that extends above and is adjacent to and covers in the upward direction and extends laterally in the lateral directions from a top of the thermal post and that contacts and overlaps the adhesive.

18. The assembly of claim 17, wherein the cap is coplanar with the pad above the posts and the adhesive and has a different thickness than the pad where the cap is adjacent to the thermal post.

19. The assembly of claim 17, wherein the cap has a rectangular or square shape and the top of the thermal post has a circular shape.

20. The assembly of claim 17, wherein the posts are copper and the base, the cap, the pad and the terminal are primarily copper.

21. A semiconductor chip assembly, comprising:

a semiconductor device;

an adhesive that includes first and second openings;

a heat spreader that includes a thermal post and a base, wherein the thermal post is adjacent to and integral with the base and extends above the base in an upward direction, the base extends below the thermal post in a downward direction opposite the upward direction, covers the thermal post in the downward direction and extends laterally from the thermal post in lateral directions orthogonal to the upward and downward directions; and

a conductive trace that includes a pad, a terminal, a routing line and a signal post, wherein the routing line is adjacent to the pad and the signal post and overlaps the signal post, the signal post is adjacent to and integral with the terminal, extends below the pad and the routing line and extends above the terminal, the terminal covers the signal post in the downward direction and extends laterally from the signal post in the lateral directions and an electrically conductive path between the pad and the terminal includes the routing line and the signal post;

wherein the semiconductor device is mounted on the heat spreader, overlaps the thermal post, does not overlap the signal post, is electrically connected to the pad and thereby electrically connected to the terminal, and is thermally connected to the thermal post and thereby thermally connected to the base;

wherein the adhesive is mounted on and extends above the base, contacts the posts, the base and the terminal, covers and surrounds the posts in the lateral directions, extends laterally from the thermal post to or beyond the terminal and extends to peripheral edges of the assembly;

wherein the pad extends above the posts and the adhesive; and

wherein the thermal post fills and is contained within the first opening, the signal post fills and is contained within the second opening, the posts have the same thickness and are coplanar with one another and with the adhesive between top and bottom surfaces of the pad and are a metal, and the base and the terminal have the same thickness and are coplanar with one another below the posts and the adhesive and are the same metallic material and include the metal.

22. The assembly of claim 21, wherein the semiconductor device is a semiconductor chip, is mounted on the heat spreader using a die attach, is electrically connected to the pad using a wire bond and is thermally connected to the heat spreader using the die attach.

23. The assembly of claim 21, wherein the thermal post has a diameter that decreases as it extends upwardly from the base to the cap, and the signal post has a diameter that decreases as it extends upwardly from the terminal to the routing line.

24. The assembly of claim 21, wherein a cap extends above and is adjacent to and covers in the upward direction and extends laterally in the lateral directions from the top of the thermal post and contacts and overlaps the adhesive.

25. The assembly of claim 24, wherein the cap is coplanar with the pad above the posts and the adhesive and has a different thickness than the pad where the cap is adjacent to the thermal post.

26. A semiconductor chip assembly, comprising:

a semiconductor device;

an adhesive that includes first and second openings;

a heat spreader that includes a thermal post and a base, wherein the thermal post is adjacent to and integral with the base and extends above the base in an upward direction, and the base extends below the thermal post in a downward direction opposite the upward direction, covers the thermal post in the downward direction and extends laterally from the thermal post in lateral directions orthogonal to the upward and downward directions;

a substrate that includes a dielectric layer, wherein first and second apertures extend through the substrate; and

a conductive trace that includes a pad, a terminal and a signal post, wherein the signal post extends below the pad and above the terminal and an electrically conductive path between the pad and the terminal includes the signal post;

wherein the semiconductor device is mounted on the heat spreader, overlaps the thermal post, is electrically connected to the pad and thereby electrically connected to the terminal, and is thermally connected to the thermal post and thereby thermally connected to the base;

wherein the adhesive is mounted on and extends above the base, extends through a first gap in the first aperture between the thermal post and the substrate and through a second gap in the second aperture between the signal post and the substrate, extends across the dielectric layer in the gaps, contacts the thermal post and the dielectric layer in the first gap, contacts the signal post and the dielectric layer in the second gap, contacts the base, the terminal and the dielectric layer outside the gaps, extends laterally from the thermal post to or beyond the terminal and is sandwiched between the thermal post and the dielectric layer, between the signal post and the dielectric layer and between the base and the dielectric layer;

wherein the substrate is mounted on the adhesive and extends above the base;

wherein the pad extends above the posts, the adhesive and the dielectric layer; and

wherein the thermal post extends into the first opening and the first aperture and above and below the dielectric layer, the signal post extends into the second opening and the second aperture and above and below the dielectric layer, the posts have the same thickness and are coplanar with one another between top and bottom surfaces of the pad and are the same metallic material as one another, the base and the terminal have the same thickness and are coplanar with one another below the posts, the adhesive and the dielectric layer and are the same metallic material as one another, and the base extends below the semiconductor device and the pad.

27. The assembly of claim 26, wherein the semiconductor device is an LED package that includes an LED chip.

28. The assembly of claim 27, wherein the LED package is electrically connected to the pad using a first solder joint and is thermally connected to the heat spreader using a second solder joint.

29. The assembly of claim 26, wherein the semiconductor device is a semiconductor chip.

30. The assembly of claim 29, wherein the chip is electrically connected to the pad using a wire bond and is thermally connected to the heat spreader using a die attach.

31. The assembly of claim 26, wherein the adhesive is a solidified prepreg.

32. The assembly of claim 26, wherein the adhesive covers and surrounds the posts in the lateral directions.

33. The assembly of claim 26, wherein the adhesive conformally coats sidewalls of the posts.

34. The assembly of claim 26, wherein the adhesive is coplanar with tops and bottoms of the posts.

35. The assembly of claim 26, wherein the adhesive extends laterally from the thermal post beyond the terminal.

36. The assembly of claim 26, wherein the adhesive extends to peripheral edges of the assembly.

37. The assembly of claim 26, wherein the thermal post fills and is contained within the first opening, the signal post fills and is contained within the second opening, the thermal post and the adhesive in combination fill the first aperture, the signal post and the adhesive in combination fill the second aperture and the posts are copper.

38. The assembly of claim 26, wherein the thermal post has a diameter that decreases as it extends upwardly from the base to its flat top, and the signal post has a diameter that decreases as it extends upwardly from the terminal to its flat top.

39. The assembly of claim 26, wherein the posts are coplanar with the adhesive between the top and bottom surfaces of the pad.

40. The assembly of claim 26, wherein the posts are copper and the base, the pad and the terminal are primarily copper.

41. The assembly of claim 26, wherein the terminal is adjacent to and integral with the signal post, covers the signal post in the downward direction and extends laterally from the signal post in the lateral directions.

42. The assembly of claim 26, wherein the heat spreader includes a cap that extends above and is adjacent to and covers in the upward direction and extends laterally in the lateral directions from the top of the thermal post and that contacts and overlaps the adhesive and the dielectric layer.

43. The assembly of claim 42, wherein the cap is coplanar with the pad above the posts, the adhesive and the dielectric layer and has a different thickness than the pad where the cap is adjacent to the thermal post.

44. The assembly of claim 42, wherein the cap has a rectangular or square shape and the top of the thermal post has a circular shape.

45. The assembly of claim 42, wherein the posts are copper and the base, the cap, the pad and the terminal are primarily copper.

46. A semiconductor chip assembly, comprising:

a semiconductor device;

an adhesive that includes first and second openings;

a heat spreader that includes a thermal post, a base and a cap, wherein the thermal post is adjacent to and integral with the base, extends above the base in an upward direction and thermally connects the base and the cap, the base extends below the thermal post in a downward direction opposite the upward direction, covers the thermal post in the downward direction and extends laterally from the thermal post in lateral directions orthogonal to the upward and downward directions, and the cap extends above and is adjacent to and covers in the upward direction and extends laterally in the lateral directions from a top of the thermal post;

a substrate that includes a dielectric layer, wherein first and second apertures extend through the substrate;

a conductive trace that includes a pad, a routing line, a terminal and a signal post, wherein the routing line is adjacent to the pad and the signal post and overlaps the signal post, the signal post is adjacent to and integral with the terminal, extends below the pad and the routing line and extends above the terminal, the terminal covers the signal post in the downward direction and extends laterally from the signal post in the lateral directions and an electrically conductive path between the pad and the terminal includes the routing line and the signal post;

wherein the semiconductor device is mounted on the cap, overlaps the thermal post, does not overlap the signal post, is electrically connected to the pad and thereby electrically connected to the terminal, and is thermally connected to the cap and thereby thermally connected to the base;

wherein the adhesive is mounted on and extends above the base, extends through a first gap in the first aperture between the thermal post and the substrate and through a second gap in the second aperture between the signal post and the substrate, extends across the dielectric layer in the gaps, contacts the thermal post and the dielectric layer in the first gap, contacts the signal post and the dielectric layer in the second gap, contacts the base, the terminal and the dielectric layer outside the gaps, is sandwiched between the thermal post and the dielectric layer, between the signal post and the dielectric layer and between the base and the dielectric layer, covers and surrounds the posts in the lateral directions, extends laterally from the thermal post to or beyond the terminal and extends to peripheral edges of the assembly;

wherein the pad extends above the posts, the adhesive and the dielectric layer; and

wherein the thermal post fills and is contained within the first opening and extends through the first aperture, the signal post fills and is contained within the second opening and extends through the second aperture, the thermal post and the adhesive in combination fill the first aperture, the signal post and the adhesive in combination fill the second aperture, the cap contacts and overlaps the adhesive, the routing line contacts and overlaps the adhesive and the dielectric layer, the posts have the same thickness and are coplanar with one another and with the adhesive between top and bottom surfaces of the pad and are a metal, the base and the terminal have the same thickness and are coplanar with one another and extend below the posts, the adhesive and the dielectric layer and are the same metallic material and are primarily the metal, and the base extends below the semiconductor device and the pad.

47. The assembly of claim 46, wherein the semiconductor device is a semiconductor chip, is mounted on the cap using a die attach, is electrically connected to the pad using a wire bond and is thermally connected to the cap using the die attach.

48. The assembly of claim 46, wherein the thermal post has a diameter that decreases as it extends upwardly from the base to the cap, and the signal post has a diameter that decreases as it extends upwardly from the terminal to the routing line.

49. The assembly of claim 46, wherein the cap contacts the substrate.

50. The assembly of claim 46, wherein the cap is coplanar with the pad above the posts, the adhesive and the dielectric layer and has a different thickness than the pad where the cap is adjacent to the thermal post.

51. A semiconductor chip assembly, comprising:

a semiconductor device;

an adhesive that includes first and second openings;

a heat spreader that includes a thermal post and a base, wherein the thermal post is adjacent to and integral with the base and extends above the base in an upward direction, and the base extends below the thermal post in a downward direction opposite the upward direction, covers the thermal post in the downward direction and extends laterally from the thermal post in lateral directions orthogonal to the upward and downward directions; and

a conductive trace that includes a pad, a terminal and a signal post, wherein the signal post is adjacent to and integral with the terminal and extends below the pad and above the terminal, the terminal extends laterally from the signal post and an electrically conductive path between the pad and the terminal includes the signal post;

wherein the semiconductor device is mounted on the heat spreader, overlaps the thermal post, is electrically connected to the pad and thereby electrically connected to the terminal, and is thermally connected to the thermal post and thereby thermally connected to the base;

wherein the adhesive is mounted on and extends above the base, contacts the posts, the base, and the terminal and extends laterally from the thermal post to or beyond the terminal;

wherein the pad extends above the posts and the adhesive and the terminal extends below the posts and the adhesive; and

wherein the thermal post fills and is contained within the first opening, the signal post fills and is contained within the second opening, the posts have the same thickness and are coplanar with one another and with the adhesive between top and bottom surfaces of the pad and are a metal, the base and the terminal have the same thickness and are coplanar with one another below the posts and the adhesive and are the same metallic material and include the metal where they contact the adhesive, and the base extends below the semiconductor device and the pad.

52. The assembly of claim 51, wherein the adhesive covers and surrounds the posts in the lateral directions, conformally coats sidewalls of the posts and extends to peripheral edges of the assembly.

53. The assembly of claim 51, wherein the adhesive is a solidified prepreg.

54. The assembly of claim 51, wherein the thermal post extends into and above and below a first aperture in a dielectric layer, the signal post extends into and above and below a second aperture in the dielectric layer, the thermal post and the adhesive in combination fill the first aperture, the signal post and the adhesive in combination fill the second aperture and the dielectric layer contacts and is sandwiched between the adhesive and the pad and is spaced from the posts, the base and the terminal.

55. The assembly of claim 51, wherein the thermal post has a diameter that decreases as it extends upwardly from the base to its flat top, and the signal post has a diameter that decreases as it extends upwardly from the terminal to its flat top.

56. The assembly of claim 51, wherein the posts are copper and the base, the pad and the terminal are primarily copper.

57. The assembly of claim 51, wherein the heat spreader includes a cap that is adjacent to and covers in the upward direction and extends laterally in the lateral directions from a top of the thermal post and the cap contacts and overlaps the adhesive.

58. The assembly of claim 57, wherein the cap is coplanar with the pad above the posts and the adhesive and has a different thickness than the pad where the cap is adjacent to the thermal post.

59. The assembly of claim 57, wherein the posts, the base, the cap, the pad and the terminal include copper.

60. The assembly of claim 59, wherein the posts are copper, the base, the cap, the pad and the terminal consist of copper and a plated contact that provides a surface finish on the copper and the cap is copper where it is adjacent to the thermal post.