Method of making a semiconductor chip assembly with a post/base heat spreader and a plated through-hole

• US 8,298,868 B2
• Filed: 04/04/2011
• Issued: 10/30/2012
• 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): Wagner, Jenny L
• Assistant Examiner(s): BOYLE, ABBIGALE A
• Application Number:
  US13/079,044
• Publication Number:
  US 20110183472A1
• Time in Patent Office: 575 Days
• Field of Search: 438106-127, 438/26, 438/29, 257/99, 257/712, 257/676
• US Class Current: 438/122
• CPC Class Codes: H01L 21/486 Via connections through the substrate with or without pins
• CPC Class Codes: H01L 2224/2919 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 2224/32188 the layer connector connecting to a bonding area protruding from the surface of the item
• CPC Class Codes: H01L 2224/32225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• 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 2224/49175 Parallel arrangements
• CPC Class Codes: H01L 2224/73265 Layer and wire connectors
• CPC Class Codes: H01L 2224/83855 Hardening the adhesive by curing, i.e. thermosetting
• CPC Class Codes: H01L 2224/85207 Thermosonic bonding
• CPC Class Codes: H01L 23/3677 Wire-like or pin-like cooling fins or heat sinks
• CPC Class Codes: H01L 24/16 of an individual bump connector
• CPC Class Codes: H01L 24/29 of an individual layer connector
• 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 24/83 using a layer connector
• CPC Class Codes: H01L 24/85 using a wire connector wire bonding in general B23K20/004
• 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 2924/01013 : Aluminum [Al]
• CPC Class Codes: H01L 2924/01014 : Silicon [Si]
• CPC Class Codes: H01L 2924/01019 : Potassium [K]
• CPC Class Codes: H01L 2924/01028 : Nickel [Ni]
• CPC Class Codes: H01L 2924/01046 : Palladium [Pd]
• CPC Class Codes: H01L 2924/0105 : Tin [Sn]
• CPC Class Codes: H01L 2924/01058 : Cerium [Ce]
• CPC Class Codes: H01L 2924/01077 : Iridium [Ir]
• 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 2924/0665 : Epoxy resin
• CPC Class Codes: H01L 2924/12041 : LED
• CPC Class Codes: H01L 2924/16195 : Flat cap [not enclosing an internal cavity]
• 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

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 upward between the post and the conductive layer, solidifying the adhesive, then providing a conductive trace that includes a pad, a terminal, a plated through-hole and a selected portion of the conductive layer, mounting a semiconductor device on the post, wherein a heat spreader 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 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;

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

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 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;

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

then

providing a plated through-hole;

providing a conductive trace that includes a pad, a terminal, the plated through-hole and selected portions of the conductive layer and the base, wherein the terminal is coplanar with the base and an electrically conductive path between the pad and the terminal includes the plated through-hole;

providing a cap that is adjacent to and covers in the upward direction and extends laterally from a top of the post and that contacts and overlaps the adhesive and includes a selected portion of the conductive layer;

then

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

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, the base and the cap.

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 and defines the post;

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, 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; and

then

removing the etch mask.

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 dielectric layer on the adhesive such that the dielectric layer is sandwiched between the conductive layer and the adhesive and the aperture extends through the conductive layer and the dielectric layer, and moving the base and the conductive layer towards one another includes moving the post upward in the aperture and forcing the molten adhesive upward in the aperture such that the post and the adhesive extend above the dielectric layer.

7. The method of claim 1, wherein providing the pad and the cap includes removing selected portions of the conductive layer using an etch mask that defines the pad and the cap after forming the plated through-hole.

8. The method of claim 1, 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 plated layer on the post, the adhesive and the conductive layer; and

then

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

9. The method of claim 1, wherein providing the terminal includes removing selected portions of the base using an etch mask that defines the terminal thereby trimming the base after forming the plated through-hole.

10. The method of claim 1, wherein mounting the semiconductor device includes providing a die attach between the semiconductor device and the cap, 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 cap.

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

providing a post, a base, an adhesive and a substrate, 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 substrate,

the base covers 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, is sandwiched between the base and the substrate and is non-solidified, and

the substrate is mounted on and extends above the adhesive, wherein the substrate includes a conductive layer and a dielectric layer and the conductive layer extends above the dielectric layer;

then

flowing the adhesive into and upward in a gap located in the aperture between the post and the substrate;

solidifying the adhesive;

then

providing a plated through-hole that extends through the conductive layer, the dielectric layer, the adhesive and the base;

then

providing a conductive trace that includes a pad, a terminal and the plated through-hole, wherein the pad includes a selected portion of the conductive layer, the terminal includes a selected portion of the base that is spaced and separated from and no longer part of the base, the terminal has the same thickness as and is coplanar with the base and an electrically conductive path between the pad and the terminal includes the plated through-hole;

providing a cap that is adjacent to and covers in the upward direction and extends laterally from a top of the post and that contacts and overlaps the adhesive and the dielectric layer and includes a selected portion of the conductive layer;

then

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

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.

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 and defines the post;

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, 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; and

then removing the etch mask.

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 substrate; and

solidifying the adhesive includes curing the uncured epoxy.

14. The method of claim 11, wherein flowing the adhesive includes filling the gap with the adhesive.

15. The method of claim 11, 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 plated layer on the post, the adhesive and the conductive layer; and

then

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

16. The method of claim 11, wherein providing the pad and the plated through-hole includes:

drilling a hole through the conductive layer, the dielectric layer, the adhesive and the base after solidifying the adhesive;

then

depositing a plated layer on the post, the conductive layer, the adhesive and the base and into the hole, wherein the plated layer forms an upper plated layer that covers the post in the upward direction and the plated through-hole in the hole;

then

forming an etch mask on the upper plated layer that defines the pad;

etching the conductive layer and the upper plated layer in a pattern defined by the etch mask; and

then

removing the etch mask.

17. The method of claim 11, wherein providing the terminal includes removing selected portions of the base using an etch mask that defines the terminal thereby trimming the base after forming the plated through-hole.

18. The method of claim 11, wherein providing the terminal and the plated through-hole includes:

drilling a hole through the conductive layer, the dielectric layer, the adhesive and the base after solidifying the adhesive;

then

depositing a plated layer on the conductive layer, the adhesive and the base and into the hole, wherein the plated layer forms a lower plated layer that covers the post in the downward direction and the plated through-hole in the hole;

then

forming an etch mask on the lower plated layer that defines the terminal;

etching the base and the lower plated layer in a pattern defined by the etch mask; and

then

removing the etch mask.

19. The method of claim 11, wherein providing the pad, the terminal, the cap and the plated through-hole includes:

drilling a hole through the conductive layer, the dielectric layer, the adhesive and the base after solidifying the adhesive;

then

depositing a plated layer on the post, the conductive layer, the adhesive and the base and into the hole, wherein the plated layer forms an upper plated layer that covers the post in the upward direction, a lower plated layer that covers the post in the downward direction and the plated through-hole in the hole;

then

forming a first etch mask on the upper plated layer that defines the pad and the cap;

etching the conductive layer and the upper plated layer in a pattern defined by the first etch mask;

forming a second etch mask on the lower plated layer that defines the terminal;

etching the base and the lower plated layer in a pattern defined by the second etch mask; and

removing the etch masks.

20. The method of claim 11, wherein mounting the semiconductor device includes providing a die attach between the semiconductor device and the cap, 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 cap.

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 covers 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;

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

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

mounting the substrate on the adhesive, including inserting the post into the aperture, wherein the substrate extends above the adhesive, the conductive layer extends above the dielectric layer, the post extends through the opening into the aperture and the adhesive is sandwiched between the base and the substrate and is non-solidified;

then

applying heat to melt the adhesive;

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

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

then

providing a plated through-hole that extends through the conductive layer, the dielectric layer, the adhesive and the base;

then

providing a conductive trace that includes a pad, a terminal and the plated through-hole, wherein the pad includes a selected portion of the conductive layer, the terminal includes a selected portion of the base that is spaced and separated from and no longer part of the base, the terminal has the same thickness as and is coplanar with the base and an electrically conductive path between the pad and the terminal includes the plated through-hole;

providing a cap that is adjacent to and covers in the upward direction and extends laterally from a top of the post and that contacts and overlaps the adhesive and the dielectric layer and includes a selected portion of the conductive layer;

then

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

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.

22. The method of claim 21, 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 and defines the post;

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, 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; and

then

removing the etch mask.

23. 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 substrate; and

solidifying the adhesive includes curing the uncured epoxy.

24. The method of claim 21, wherein providing the pad, the terminal, the cap and the plated through-hole includes:

drilling a hole through the conductive layer, the dielectric layer, the adhesive and the base after solidifying the adhesive;

then

depositing a plated layer on the post, the conductive layer, the adhesive and the base and into the hole, wherein the plated layer forms an upper plated layer that covers the post in the upward direction, a lower plated layer that covers the post in the downward direction and the plated through-hole in the hole;

then

forming a first etch mask on the upper plated layer that defines the pad and the cap;

etching the conductive layer and the upper plated layer in a pattern defined by the first etch mask, thereby exposing the dielectric layer in the upward direction without exposing the adhesive in the upward direction, wherein the pad and the cap include unetched portions of the conductive layer and the upper plated layer;

forming a second etch mask on the lower plated layer that defines the terminal;

etching the base and the lower plated layer in a pattern defined by the second etch mask, thereby exposing the adhesive in the downward direction without exposing the dielectric layer in the downward direction, wherein the terminal includes unetched portions of the base and the lower plated layer; and

removing the etch masks.

25. The method of claim 21, wherein mounting the semiconductor device includes providing a die attach between the semiconductor device and the cap, 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 cap.