Method of making a semiconductor chip assembly with a post/base heat spreader and a conductive trace

• US 8,110,446 B2
• Filed: 11/13/2009
• Issued: 02/07/2012
• 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): Bryant, Kiesha
• Assistant Examiner(s): Boyle, Abbigale
• Application Number:
  US12/617,725
• Publication Number:
  US 20100055812A1
• Time in Patent Office: 816 Days
• Field of Search: 257/E23.102, 257/707, 257/711, 257/E33.056, 257/E33.075, 438/26, 438/27, 438/39, 438/118, 438/121, 438/122, 438/759
• US Class Current: 438/122
• CPC Class Codes: H01L 21/486 Via connections through the substrate with or without pins
• 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 2224/85205 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 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 33/62 : Arrangements for conducting electric current to or from the semiconductor body, e.g. lead-frames, wire-bonds or solder balls
• 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 method of making a semiconductor chip assembly includes providing a post and a base, mounting an adhesive on the base including inserting the post into an opening in the adhesive, mounting a conductive layer on the adhesive including aligning the post with an aperture in the conductive layer, then flowing the adhesive into and upward in a gap located in the aperture between the post and the conductive layer, solidifying the adhesive, then providing a conductive trace that includes a pad, a terminal and a selected portion of the conductive layer, mounting a semiconductor device on a heat spreader that includes the post and the base, electrically connecting the semiconductor device to the conductive trace and thermally connecting the semiconductor device to the heat spreader.

Claims

1. A method of making a semiconductor chip assembly, comprising:

providing a post, a base, an adhesive and a conductive layer, wherein

the post is adjacent to the base, extends above the base in an upward direction, extends into an opening in the adhesive and is aligned with an aperture in the conductive layer,

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,

the adhesive is mounted on and extends above the base, contacts and is sandwiched between the base and the conductive layer and is non-solidified, and

the conductive layer is mounted on and extends above the adhesive;

then

flowing the adhesive into and upward in a gap located in the aperture between the post and the conductive layer, wherein flowing the adhesive includes forcing the adhesive above the post and the conductive layer;

solidifying the adhesive;

then

grinding the adhesive;

then

providing a conductive trace that includes a pad, a terminal and a selected portion of the conductive layer;

mounting a semiconductor device on a heat spreader that includes the post and the base, wherein the semiconductor device overlaps the post;

electrically connecting the semiconductor device to the pad, thereby electrically connecting the semiconductor device to the terminal; and

thermally connecting the semiconductor device to the post, thereby thermally connecting the semiconductor device to the base.

2. The method of claim 1, wherein providing the post and the base includes:

providing a metal plate;

forming an etch mask on the metal plate that selectively exposes the metal plate;

etching the metal plate in a pattern defined by the etch mask, thereby forming a recess in the metal plate that extends into but not through the metal plate; and

then

removing the etch mask, wherein the post includes an unetched portion of the metal plate that protrudes above the base and is laterally surrounded by the recess, and the base includes an unetched portion of the metal plate below the post and the recess.

3. The method of claim 1, wherein:

providing the adhesive includes providing a prepreg with uncured epoxy;

flowing the adhesive includes melting the uncured epoxy and compressing the uncured epoxy between the base and the conductive layer; and

solidifying the adhesive includes curing the uncured epoxy.

4. The method of claim 1, wherein flowing the adhesive includes filling the gap with the adhesive.

5. The method of claim 1, wherein mounting the conductive layer includes mounting the conductive layer alone on the adhesive.

6. The method of claim 1, wherein:

mounting the conductive layer includes mounting the conductive layer and a carrier on the adhesive, wherein the carrier is attached to and overlaps the conductive layer and the conductive layer contacts the adhesive and is sandwiched between the adhesive and the carrier;

then

solidifying the adhesive;

then

removing the carrier; and

then

providing the conductive trace.

7. The method of claim 1, wherein providing the pad includes removing selected portions of the conductive layer after solidifying and grinding the adhesive.

8. The method of claim 1, including providing a cap on the post 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 post and that overlaps and is adjacent to the adhesive after solidifying and grinding the adhesive and before mounting the semiconductor device, wherein the heat spreader includes the cap.

9. The method of claim 1, wherein mounting the semiconductor device includes providing a first solder joint between the semiconductor device and the pad and a second solder joint between the semiconductor device and the heat spreader, electrically connecting the semiconductor device includes providing the first solder joint between the semiconductor device and the pad, and thermally connecting the semiconductor device includes providing the second solder joint between the semiconductor device and the heat spreader.

10. The method of claim 1, wherein mounting the semiconductor device includes providing a die attach between the semiconductor device and the heat spreader, electrically connecting the semiconductor device includes providing a wire bond between the semiconductor device and the pad, and thermally connecting the semiconductor device includes providing the die attach between the semiconductor device and the heat spreader.

11. A method of making a semiconductor chip assembly, comprising:

providing 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;

providing an adhesive, wherein an opening extends through the adhesive alone;

providing a conductive layer, wherein an aperture extends through the conductive layer alone;

mounting the adhesive on the base, including inserting the post into the opening, wherein the adhesive extends above the base and the post extends into the opening;

mounting the conductive layer on the adhesive, including aligning the post with the aperture, wherein the conductive layer extends above the adhesive and the adhesive contacts and is sandwiched between the base and the conductive layer and is non-solidified;

then

applying heat to melt the adhesive;

moving the base and the conductive layer towards one another, thereby moving the post upward in the aperture and applying pressure to the molten adhesive between the base and the conductive layer, wherein the pressure forces the molten adhesive to flow into and upward in a gap located in the aperture between the post and the conductive layer and flow above the post and the conductive layer;

applying heat to solidify the molten adhesive, thereby mechanically attaching the post and the base to the conductive layer;

then

grinding the adhesive;

then

providing a conductive trace that includes a pad and a terminal, wherein the conductive trace includes selected portions of the conductive layer and an electrically conductive path is between the pad and the terminal;

mounting a semiconductor device on a heat spreader that includes the post and the base, wherein the semiconductor device overlaps the post;

electrically connecting the semiconductor device to the pad, thereby electrically connecting the semiconductor device to the terminal; and

thermally connecting the semiconductor device to the post, thereby thermally connecting the semiconductor device to the base.

12. The method of claim 11, wherein providing the post and the base includes:

providing a metal plate;

forming an etch mask on the metal plate that selectively exposes the metal plate;

etching the metal plate in a pattern defined by the etch mask, thereby forming a recess in the metal plate that extends into but not through the metal plate; and

then

removing the etch mask, wherein the post includes an unetched portion of the metal plate that protrudes above the base and is laterally surrounded by the recess, and the base includes an unetched portion of the metal plate below the post and the recess.

13. The method of claim 11, wherein:

providing the adhesive includes providing a prepreg with uncured epoxy;

flowing the adhesive includes melting the uncured epoxy and compressing the uncured epoxy between the base and the conductive layer; and

solidifying the adhesive includes curing the uncured epoxy.

14. The method of claim 11, wherein mounting the conductive layer includes mounting the conductive layer alone on the adhesive.

15. The method of claim 11, wherein providing the pad includes removing selected portions of the conductive layer using an etch mask that defines the pad after solidifying and grinding the adhesive.

16. The method of claim 11, wherein providing the pad includes:

grinding the post, the adhesive and the conductive layer such that the post, the adhesive and the conductive layer are laterally aligned with one another at a top lateral surface that faces in the upward direction; and

then

removing selected portions of the conductive layer using an etch mask that defines the pad.

17. The method of claim 11, including providing a cap on the post 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 post and that overlaps and is adjacent to the adhesive after solidifying and grinding the adhesive and before mounting the semiconductor device, wherein the heat spreader includes the cap.

18. The method of claim 17, wherein providing the pad and the cap includes:

grinding the post, the adhesive and the conductive layer such that the post, the adhesive and the conductive layer are laterally aligned with one another at a top lateral surface that faces in the upward direction;

then

depositing a second conductive layer on the post, the adhesive and the conductive layer;

forming an etch mask on the second conductive layer;

etching the conductive layers using the etch mask to define the pad;

etching the second conductive layer using the etch mask to define the cap; and

then

removing the etch mask.

19. The method of claim 11, wherein mounting the semiconductor device includes mounting an LED package that includes an LED chip on the pad using a first solder joint and on the heat spreader using a second solder joint, electrically connecting the semiconductor device includes providing the first solder joint between the LED package and the pad, and thermally connecting the semiconductor device includes providing the second solder joint between the LED package and the heat spreader.

20. The method of claim 11, wherein mounting the semiconductor device includes providing a die attach between the semiconductor device and the heat spreader, electrically connecting the semiconductor device includes providing a wire bond between the semiconductor device and the pad, and thermally connecting the semiconductor device includes providing the die attach between the semiconductor device and the heat spreader.

21. A method of making a semiconductor chip assembly, comprising:

providing 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;

providing an adhesive, wherein an opening extends through the adhesive alone;

providing a conductive layer, wherein an aperture extends through the conductive layer alone;

mounting the adhesive on the base, including inserting the post into the opening, wherein the adhesive extends above the base and the post extends into the opening;

mounting the conductive layer alone on the adhesive, including aligning the post with the aperture, wherein the conductive layer extends above the adhesive, the post extends into the opening and the adhesive contacts and is sandwiched between the base and the conductive layer and is non-solidified;

then

applying heat to melt the adhesive;

moving the base and the conductive layer towards one another, thereby moving the post upward in the aperture and applying pressure to the molten adhesive between the base and the conductive layer, wherein the pressure forces the molten adhesive to flow into and upward in a gap located in the aperture between the post and the conductive layer and flow above the post and the conductive layer;

applying heat to solidify the molten adhesive, thereby mechanically attaching the post and the base to the conductive layer;

then

grinding the adhesive;

then

providing a conductive trace that includes a pad and a terminal, including removing selected portions of the conductive layer using an etch mask that defines the pad and the terminal, wherein the pad and the terminal include selected portions of the conductive layer and an electrically conductive path is between the pad and the terminal;

then

mounting a semiconductor device on a heat spreader that includes the post and the base, wherein the semiconductor device overlaps the post;

electrically connecting the semiconductor device to the pad, thereby electrically connecting the semiconductor device to the terminal; and

thermally connecting the semiconductor device to the post, thereby thermally connecting the semiconductor device to the base.

22. The method of claim 21, wherein:

providing the adhesive includes providing a prepreg with uncured epoxy;

flowing the adhesive includes melting the uncured epoxy and compressing the uncured epoxy between the base and the conductive layer; and

solidifying the adhesive includes curing the uncured epoxy.

23. The method of claim 21, wherein providing the pad includes:

grinding the post, the adhesive and the conductive layer such that the post, the adhesive and the conductive layer are laterally aligned with one another at a top lateral surface that faces in the upward direction;

then

forming the etch mask over the conductive layer;

etching the conductive layer using the etch mask to define the pad; and

then

removing the etch mask.

24. The method of claim 21, wherein mounting the semiconductor device includes mounting an LED package that includes an LED chip on the pad using a first solder joint and on the heat spreader using a second solder joint, electrically connecting the semiconductor device includes providing the first solder joint between the LED package and the pad, and thermally connecting the semiconductor device includes providing the second solder joint between the LED package and the heat spreader.

25. The method of claim 21, wherein mounting the semiconductor device includes providing a die attach between the semiconductor device and the heat spreader, electrically connecting the semiconductor device includes providing a wire bond between the semiconductor device and the pad, and thermally connecting the semiconductor device includes providing the die attach between the semiconductor device and the heat spreader.

26. A method of making a semiconductor chip assembly, comprising:

providing 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;

providing an adhesive, wherein an opening extends through the adhesive alone;

providing a conductive layer, wherein an aperture extends through the conductive layer alone;

mounting the adhesive on the base, including inserting the post into the opening, wherein the adhesive extends above the base and the post extends into the opening;

mounting the conductive layer on the adhesive, including aligning the post with the aperture, wherein the conductive layer extends above the adhesive and the adhesive contacts and is sandwiched between the base and the conductive layer and is non-solidified;

then

applying heat to melt the adhesive;

moving the base and the conductive layer towards one another, thereby moving the post upward in the aperture and applying pressure to the molten adhesive between the base and the conductive layer, wherein the pressure forces the molten adhesive to flow into and upward in a gap located in the aperture between the post and the conductive layer and flow above the post and the conductive layer onto top surfaces of the post and the conductive layer;

applying heat to solidify the molten adhesive, thereby mechanically attaching the post and the base to the conductive layer;

then

grinding the post and the adhesive;

then

providing a conductive trace that includes a pad and a terminal, wherein the conductive trace includes selected portions of the conductive layer and an electrically conductive path is between the pad and the terminal;

providing a cap on the post 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 post and that overlaps and is adjacent to the adhesive, wherein a heat spreader includes the post, the base and the cap;

then

mounting a semiconductor device on the cap, wherein the semiconductor device overlaps the post;

electrically connecting the semiconductor device to the pad, thereby electrically connecting the semiconductor device to the terminal; and

thermally connecting the semiconductor device to the cap, thereby thermally connecting the semiconductor device to the base.

27. The method of claim 26, wherein providing the post and the base includes:

providing a metal plate;

forming an etch mask on the metal plate that selectively exposes the metal plate;

etching the metal plate in a pattern defined by the etch mask, thereby forming a recess in the metal plate that extends into but not through the metal plate; and

then

removing the etch mask, wherein the post includes an unetched portion of the metal plate that protrudes above the base and is laterally surrounded by the recess, and the base includes an unetched portion of the metal plate below the post and the recess.

28. The method of claim 26, wherein:

providing the adhesive includes providing a prepreg with uncured epoxy;

flowing the adhesive includes melting the uncured epoxy and compressing the uncured epoxy between the base and the conductive layer; and

solidifying the adhesive includes curing the uncured epoxy.

29. The method of claim 26, wherein flowing the adhesive includes filling the gap with the adhesive.

30. The method of claim 26, wherein flowing the adhesive includes forcing the adhesive above the post and the conductive layer.

31. The method of claim 26, wherein flowing the adhesive and moving the post includes filling the aperture with the post and the adhesive.

32. The method of claim 26, wherein mounting the conductive layer includes mounting the conductive layer alone on the adhesive.

33. The method of claim 26, wherein providing the pad includes:

grinding the post, the adhesive and the conductive layer such that the post, the adhesive and the conductive layer are laterally aligned with one another at a top lateral surface that faces in the upward direction;

then

depositing a second conductive layer on the post, the adhesive and the conductive layer; and

then

etching the conductive layers using an etch mask that defines the pad.

34. The method of claim 26, wherein providing the terminal includes:

grinding the post, the adhesive and the conductive layer such that the post, the adhesive and the conductive layer are laterally aligned with one another at a top lateral surface that faces in the upward direction;

then

depositing a second conductive layer on the post, the adhesive and the conductive layer; and

then

etching the conductive layers using an etch mask that defines the terminal.

35. The method of claim 26, wherein providing the cap includes:

grinding the post, the adhesive and the conductive layer such that the post, the adhesive and the conductive layer are laterally aligned with one another at a top lateral surface that faces in the upward direction;

then

depositing a second conductive layer on the post, the adhesive and the conductive layer; and

then

etching the second conductive layer using an etch mask that defines the cap.

36. A method of making a semiconductor chip assembly, comprising:

providing 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;

providing an adhesive, wherein an opening extends through the adhesive alone;

providing a conductive layer, wherein an aperture extends through the conductive layer alone;

mounting the adhesive on the base, including inserting the post into the opening, wherein the adhesive extends above the base and the post extends into the opening;

mounting the conductive layer on the adhesive, including aligning the post with the aperture, wherein the conductive layer extends above the adhesive and the adhesive contacts and is sandwiched between the base and the conductive layer and is non-solidified;

then

applying heat to melt the adhesive;

moving the base and the conductive layer towards one another, thereby moving the post upward in the aperture and applying pressure to the molten adhesive between the base and the conductive layer, wherein the pressure forces the molten adhesive to flow into and upward in a gap located in the aperture between the post and the conductive layer and flow laterally into the post;

applying heat to solidify the molten adhesive, thereby mechanically attaching the post and the base to the conductive layer;

then

depositing a second conductive layer on the post, the adhesive and the conductive layer;

then

providing a conductive trace that includes a pad and a terminal, including etching the conductive layers such that the pad includes selected portions of the conductive layers;

providing a cap on the post 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 post and that overlaps and is adjacent to the adhesive, including etching the second conductive layer such that the cap includes a selected portion of the second conductive layer;

then

mounting a semiconductor device on a heat spreader that includes the post, the base and the cap, wherein the semiconductor device overlaps the post;

electrically connecting the semiconductor device to the pad, thereby electrically connecting the semiconductor device to the terminal; and

thermally connecting the semiconductor device to the cap, thereby thermally connecting the semiconductor device to the base.

37. The method of claim 36, wherein providing the post and the base includes:

providing a metal plate;

forming an etch mask on the metal plate that selectively exposes the metal plate;

etching the metal plate in a pattern defined by the etch mask, thereby forming a recess in the metal plate that extends into but not through the metal plate; and

then

removing the etch mask, wherein the post includes an unetched portion of the metal plate that protrudes above the base and is laterally surrounded by the recess, and the base includes an unetched portion of the metal plate below the post and the recess.

38. The method of claim 36, wherein:

providing the adhesive includes providing a prepreg with uncured epoxy;

flowing the adhesive includes melting the uncured epoxy and compressing the uncured epoxy between the base and the conductive layer; and

solidifying the adhesive includes curing the uncured epoxy.

39. The method of claim 36, wherein flowing the adhesive includes filling the gap with the adhesive.

40. The method of claim 36, wherein flowing the adhesive includes forcing the adhesive above the post and the conductive layer.

41. The method of claim 36, wherein flowing the adhesive and moving the post includes filling the aperture with the post and the adhesive.

42. The method of claim 36, wherein mounting the conductive layer includes mounting the conductive layer alone on the adhesive.

43. The method of claim 36, wherein providing the pad includes:

grinding the post, the adhesive and the conductive layer such that the post, the adhesive and the conductive layer are laterally aligned with one another at a top lateral surface that faces in the upward direction;

then

depositing the second conductive layer on the post, the adhesive and the conductive layer; and

then

etching the conductive layers using an etch mask that defines the pad.

44. The method of claim 36, wherein providing the pad and the terminal includes:

grinding the post, the adhesive and the conductive layer such that the post, the adhesive and the conductive layer are laterally aligned with one another at a top lateral surface that faces in the upward direction;

then

depositing the second conductive layer on the post, the adhesive and the conductive layer; and

then

etching the conductive layers using an etch mask that defines the pad and the terminal.

45. The method of claim 36, wherein providing the pad and the cap includes:

grinding the post, the adhesive and the conductive layer such that the post, the adhesive and the conductive layer are laterally aligned with one another at a top lateral surface that faces in the upward direction;

then

depositing the second conductive layer on the post, the adhesive and the conductive layer; and

then

etching the conductive layers using an etch mask that defines the pad and the cap.