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

• US 8,212,279 B2
• Filed: 07/10/2010
• Issued: 07/03/2012
• 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, Lim, Sangwhoo
• Primary Examiner(s): Nguyen, Dao H
• Assistant Examiner(s): Nguyen, Tram H
• Application Number:
  US12/833,947
• Publication Number:
  US 20110049558A1
• Time in Patent Office: 724 Days
• Field of Search: 257/99, 257/384, 257/712, 257/711, 257/717, 257/707, 257/713, 257/784, 257/E23.102, 257/E23.101, 438/26, 438/27, 438/122, 438/612, 438/39, 438/121, 438/118, 438/464, 438/669, 438/670
• US Class Current: 257/99
• CPC Class Codes: H01L 21/486 Via connections through the substrate with or without pins
• CPC Class Codes: H01L 2224/04105 Bonding areas formed on an encapsulation of the semiconductor or solid-state body, e.g. bonding areas on chip-scale packages
• CPC Class Codes: H01L 2224/20 Structure, shape, material or disposition of high density interconnect preforms
• CPC Class Codes: H01L 2224/2929 with a principal constituent of the material being a polymer, e.g. polyester, phenolic based polymer, epoxy
• CPC Class Codes: H01L 2224/29339 Silver [Ag] as principal constituent
• CPC Class Codes: H01L 2224/45144 Gold (Au) as principal constituent
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/49171 Fan-out arrangements
• CPC Class Codes: H01L 2224/73265 Layer and wire connectors
• CPC Class Codes: H01L 2224/8385 using a polymer adhesive, e.g. an adhesive based on silicone, epoxy, polyimide, polyester
• 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 23/5389 the chips being integrally enclosed by the interconnect and support structures
• 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 2924/00014 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 2924/01005 Boron [B]
• CPC Class Codes: H01L 2924/01006 Carbon [C]
• CPC Class Codes: H01L 2924/01012 Magnesium [Mg]
• CPC Class Codes: H01L 2924/01013 Aluminum [Al]
• CPC Class Codes: H01L 2924/01019 Potassium [K]
• CPC Class Codes: H01L 2924/01029 : Copper [Cu]
• CPC Class Codes: H01L 2924/01033 : Arsenic [As]
• CPC Class Codes: H01L 2924/0104 : Zirconium [Zr]
• CPC Class Codes: H01L 2924/01047 : Silver [Ag]
• CPC Class Codes: H01L 2924/01049 : Indium [In]
• CPC Class Codes: H01L 2924/01058 : Cerium [Ce]
• CPC Class Codes: H01L 2924/01074 : Tungsten [W]
• CPC Class Codes: H01L 2924/01079 : Gold [Au]
• CPC Class Codes: H01L 2924/01082 : Lead [Pb]
• CPC Class Codes: H01L 2924/01087 : Francium [Fr]
• CPC Class Codes: H01L 2924/014 : Solder alloys
• CPC Class Codes: H01L 2924/0665 : Epoxy resin
• CPC Class Codes: H01L 2924/15153 : the die mounting substrate comprising a recess for hosting the device
• CPC Class Codes: H01L 2924/351 : Thermal stress
• CPC Class Codes: H01L 33/486 : adapted for surface mounting
• CPC Class Codes: H01L 33/642 : characterized by the shape

Abstract

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

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 a cavity is defined by and laterally surrounded by the heat spreader, extends into the thermal post and the first opening, faces in the upward direction and is covered by the base in the downward direction;

wherein the semiconductor device is mounted on the heat spreader, extends into the cavity and is covered by the cavity in the downward direction, is electrically connected to the pad and thereby electrically connected to the terminal, and is thermally connected to the thermal post and the base;

wherein the adhesive is mounted on and extends above the base, is located outside the cavity, extends laterally from the thermal post to or beyond the terminal and is sandwiched between the base and the pad;

wherein the conductive trace is located outside the cavity; and

wherein the thermal post extends into the first opening, the signal post extends into the second opening, the posts are the same metallic material and have the same thickness and are coplanar with one another, and the base and the terminal are the same metallic material and have the same thickness and are coplanar with one another.

2. The assembly of claim 1, wherein the semiconductor device is located within the cavity.

3. The assembly of claim 1, wherein the semiconductor device is an LED chip.

4. The assembly of claim 1, wherein the semiconductor device is electrically connected to the pad using a wire bond that extends outside the cavity and is thermally connected to the heat spreader using a die attach.

5. The assembly of claim 1, wherein the adhesive contacts the posts, the base and the terminal.

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

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

8. The assembly of claim 1, wherein the adhesive is coplanar with tops of the posts.

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

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

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

12. The assembly of claim 1, wherein the thermal post is coplanar with the adhesive at the base and the signal post is coplanar with the adhesive at the terminal.

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

14. The assembly of claim 1, wherein the heat spreader includes a cap that extends above and is adjacent to and extends laterally from the thermal post and that contacts and overlaps the adhesive, and the cavity extends through the cap into the thermal post.

15. The assembly of claim 14, wherein the cap is coplanar with the pad and is adjacent to the thermal post between top and bottom surfaces of the pad.

16. 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 extends above the terminal and an electrically conductive path between the pad and the terminal includes the signal post;

wherein a cavity is defined by and laterally surrounded by the heat spreader, extends into the thermal post, the first opening and the first aperture, faces in the upward direction and is covered by the base in the downward direction;

wherein the semiconductor device is located within the cavity, is electrically connected to the pad and thereby electrically connected to the terminal, and is thermally connected to the thermal post and the base;

wherein the adhesive is mounted on and extends above the base and the terminal, is located outside the cavity, extends between the thermal post and the substrate, extends between the signal post and the substrate, 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, between the base and the dielectric layer and between the terminal and the dielectric layer;

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

wherein the conductive trace is located outside the cavity; and

wherein the thermal post extends into the first opening and the first aperture, the signal post extends into the second opening and the second aperture, the posts are the same metallic material and have the same thickness and are coplanar with one another, and the base and the terminal are the same metallic material and have the same thickness and are coplanar with one another.

17. The assembly of claim 16, wherein the semiconductor device is an LED chip.

18. The assembly of claim 16, wherein the semiconductor device is electrically connected to the pad using a wire bond that extends within and outside the cavity and is thermally connected to the thermal post using a die attach that is located within the cavity.

19. The assembly of claim 16, wherein the adhesive contacts the posts, the base, the terminal and the dielectric layer.

20. The assembly of claim 16, wherein the adhesive covers and surrounds the posts in the lateral directions and conformally coats sidewalls of the posts.

21. The assembly of claim 16, wherein the adhesive extends to peripheral edges of the assembly.

22. The assembly of claim 16, wherein the posts are coplanar with the adhesive above and below the dielectric layer.

23. The assembly of claim 16, wherein the posts are coplanar with the adhesive between top and bottom surfaces of the pad.

24. The assembly of claim 16, wherein the thermal post fills and is contained within the first opening and the signal post fills and is contained within the second opening.

25. The assembly of claim 16, wherein the thermal post and the adhesive in combination fill the first aperture and the signal post and the adhesive in combination fill the second aperture.

26. The assembly of claim 16, wherein the thermal post has a diameter that decreases as it extends upwardly from the base to its top, the signal post has a diameter that decreases as it extends upwardly from the terminal to its top, and the cavity has a diameter that increases as it extends upwardly in the thermal post.

27. The assembly of claim 16, wherein the cavity extends through the first aperture.

28. The assembly of claim 16, wherein the base covers the thermal post in the downward direction, supports the substrate and is spaced from peripheral edges of the assembly.

29. The assembly of claim 16, wherein the heat spreader includes a cap that extends above and is adjacent to and extends laterally from the thermal post and that contacts and overlaps the adhesive and the dielectric layer, and the cavity extends through the cap into the thermal post.

30. The assembly of claim 29, wherein the cap covers the opening and the aperture in the upward direction, is coplanar with the pad above the adhesive and the dielectric layer and is adjacent to the thermal post between top and bottom surfaces of the pad.

31. 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 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 the cap extends above and is adjacent to and extends laterally from 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 terminal and a signal post, wherein the signal post extends below the pad and extends above the terminal and an electrically conductive path between the pad and the terminal includes the signal post;

wherein a cavity is defined by and laterally surrounded by the post and the cap, extends through the cap into the thermal post, the first opening and the first aperture, faces in the upward direction and is covered by the thermal post in the downward direction;

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

wherein the substrate is mounted on the adhesive and extends above the base and the terminal and the dielectric layer contacts the pad and is spaced from the posts, the base and the terminal;

wherein the conductive trace is located outside the cavity and the pad extends above the dielectric layer;

wherein the cap contacts and overlaps the adhesive and the dielectric layer and is coplanar with the pad above the adhesive and the dielectric layer at a surface that faces in the upward direction; and

wherein the thermal post extends into the first opening and the first aperture, the signal post extends into the second opening and the second aperture, the posts are the same metallic material and have the same thickness and are coplanar with one another and extend through the dielectric layer, and the base and the terminal are the same metallic material and have the same thickness and are coplanar with one another and are located below the dielectric layer.

32. The assembly of claim 31, wherein the semiconductor device is an LED chip, is mounted on the thermal post using a die attach, is electrically connected to the pad using a wire bond that extends within and outside the cavity and is thermally connected to the thermal post using the die attach.

33. The assembly of claim 31, wherein the posts are coplanar with the adhesive above the dielectric layer between top and bottom surfaces of the pad, the thermal post is coplanar with the adhesive below the dielectric layer at the base and the signal post is coplanar with the adhesive below the dielectric layer at the terminal.

34. The assembly of claim 31, 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.

35. The assembly of claim 31, wherein the thermal post has a diameter that decreases as it extends upwardly from the base to the cap, the signal post has a diameter that decreases as it extends upwardly from the terminal and the cavity has a diameter that increases as it extends upwardly in the thermal post and the cap.