Semiconductor chip assembly with aluminum post/base heat spreader and silver/copper conductive trace

• US 8,232,573 B2
• Filed: 03/10/2010
• Issued: 07/31/2012
• 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): Cao, Phat X
• Application Number:
  US12/721,551
• Publication Number:
  US 20100163921A1
• Time in Patent Office: 874 Days
• Field of Search: 257/98, 257/99, 438/22, 438/25, 438/26
• US Class Current: 257/98
• CPC Class Codes: F21K 9/00 Light sources using semiconductor devices as light-generating elements, e.g. using light-emitting diodes [LED] or lasers
• CPC Class Codes: H01L 21/486 Via connections through the substrate with or without pins
• CPC Class Codes: H01L 2224/05599 Material
• 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 2224/48227 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/49171 Fan-out arrangements
• 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 24/45 of an individual wire connector
• CPC Class Codes: H01L 24/48 of an individual wire connector
• CPC Class Codes: H01L 24/49 of a plurality of wire connectors
• 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 2924/12041 : LED
• CPC Class Codes: H01L 2924/181 : Encapsulation
• CPC Class Codes: H01L 2924/19041 : being a capacitor
• CPC Class Codes: H01L 33/483 : Containers
• 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
• CPC Class Codes: H05K 3/386 : by the use of an organic polymeric bonding layer, e.g. adhesive

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 is aluminum and includes a post and a base. The post extends upwardly from the base into an opening in the adhesive, and the base extends laterally from the post. The adhesive extends between the post and the conductive trace and between the base and the conductive trace. The conductive trace includes a silver coating and a copper core and provides signal routing between a pad and a terminal.

Claims

1. A semiconductor chip assembly, comprising:

a semiconductor device;

an adhesive that includes an opening;

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

a conductive trace that includes a pad and a terminal, wherein the conductive trace further includes a silver coating and a copper core and the silver coating is located above and overlaps the copper core;

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

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

wherein a top surface of the copper core is coplanar with the post and the adhesive at a lateral surface that faces in the upward direction; and

wherein the post extends into the opening, and the base extends below the semiconductor device and the pad.

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

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 and is thermally connected to the post using a die attach.

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

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

7. The assembly of claim 1, wherein the adhesive conformally coats sidewalls of the post and a top surface of the base outside the post.

8. The assembly of claim 1, wherein the adhesive fills the space between the base and the conductive trace.

9. The assembly of claim 1, wherein the adhesive extends laterally from the post beyond and is overlapped by 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 silver coating contacts the copper core.

12. The assembly of claim 1, wherein the silver coating is spaced from the copper core and a nickel buffer layer contacts and is sandwiched between the silver coating and the copper core.

13. The assembly of claim 1, wherein the post is coplanar with the adhesive at the base.

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

15. The assembly of claim 1, wherein the base covers the semiconductor device, the post, the adhesive and the conductive trace in the downward direction and extends to peripheral edges of the assembly.

16. A semiconductor chip assembly, comprising:

a semiconductor device;

an adhesive that includes an opening;

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

a substrate that includes a dielectric layer, wherein an aperture extends through the substrate; and

a conductive trace that includes a pad and a terminal, wherein the conductive trace further includes a silver coating and a copper core, the silver coating is located above and overlaps the copper core and the silver coating and the copper core provide portions of the pad;

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

wherein the adhesive is mounted on and extends above the base, extends into a gap in the aperture between the post and the substrate, extends across the dielectric layer in the gap, extends laterally from the post to or beyond the terminal and is sandwiched between the 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 a top of surface of the copper core is coplanar with the post and the adhesive at a lateral surface that faces in the upward direction; and

wherein the post extends into the opening and the aperture, and the base extends below the semiconductor device and the substrate.

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 and is thermally connected to the post using a die attach.

19. The assembly of claim 16, wherein the adhesive contacts the post and the dielectric layer in the gap and contacts the base and the dielectric layer outside the gap.

20. The assembly of claim 16, wherein the adhesive covers and surrounds the post in the lateral directions.

21. The assembly of claim 16, wherein the adhesive fills the space between the post and the dielectric layer.

22. The assembly of claim 16, wherein the adhesive fills the space between the base and the substrate.

23. The assembly of claim 16, wherein the adhesive is contained in the space between the heat spreader and the substrate.

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

25. The assembly of claim 16, wherein the silver coating contacts the copper core and the conductive trace consists of the silver coating and the copper core.

26. The assembly of claim 16, wherein the silver coating is spaced from the copper core, a nickel buffer layer contacts and is sandwiched between the silver coating and the copper core and the conductive trace consists of the silver coating, the nickel buffer layer and the copper core.

27. The assembly of claim 16, wherein the silver coating is a top surface layer and the copper core is a buried layer.

28. The assembly of claim 16, wherein the post is coplanar with the adhesive below the dielectric layer.

29. The assembly of claim 16, wherein the post has a diameter that decreases as it extends upwardly from the base to its flat top.

30. The assembly of claim 16, wherein the base covers the semiconductor device, the post, the adhesive, the conductive trace and the substrate in the downward direction and extends to peripheral edges of the assembly.

31. A semiconductor chip assembly, comprising:

a semiconductor device;

an adhesive that includes an opening;

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

a substrate that includes a conductive trace and a dielectric layer, wherein the conductive trace includes a pad, a terminal and a routing line that contact and extend above the dielectric layer, a silver coating and a copper core provide portions of the pad and the terminal, the copper core provides the routing line, the silver coating is located above and overlaps the copper core, a top surface of the copper core is coplanar with the post and the adhesive above the dielectric layer at a lateral surface that faces in the upward direction, an electrically conductive path between the pad and the terminal includes the routing line, and an aperture extends through the substrate;

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

wherein the adhesive is mounted on and extends above the base, extends into a gap in the aperture between the post and the substrate, extends across the dielectric layer in the gap, is sandwiched between the post and the dielectric layer in the gap, is sandwiched between the base and the substrate outside the gap, surrounds the post in the lateral directions, is overlapped by the pad, the terminal and the routing line, extends laterally from the post to or beyond the terminal and extends to peripheral edges of the assembly;

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

wherein the post extends into the opening and the aperture and above the dielectric layer, and the base covers the semiconductor device, the post, the adhesive and the substrate in the downward direction and extends to peripheral edges of the assembly.

32. The assembly of claim 31, wherein the semiconductor device is an LED chip, is electrically connected to the pad using a wire bond and is thermally connected to the post using a die attach.

33. The assembly of claim 31, wherein the substrate is spaced from the post and the base, the adhesive contacts the post and the dielectric layer in the gap and contacts the base and the dielectric layer outside the gap, the silver coating is a top surface layer and the copper core is a buried layer.

34. The assembly of claim 31, wherein the post has a diameter that decreases as it extends upwardly from the base to its flat top.

35. The assembly of claim 31, wherein the post is coplanar with the adhesive below the dielectric layer at the base.