Semiconductor chip assembly with bump/base heat spreader and cavity in bump

• US 8,314,438 B2
• Filed: 10/26/2010
• Issued: 11/20/2012
• 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:
  US12/911,729
• Publication Number:
  US 20110037094A1
• Time in Patent Office: 756 Days
• Field of Search: 257/98, 257/99, 257/E33.075
• US Class Current: 257/98
• CPC Class Codes: H01L 21/486 Via connections through the substrate with or without pins
• 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 2224/48225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/48227 connecting the wire to a bond pad of the item
• 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 2224/8592 Applying permanent coating, e.g. protective coating
• 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 2924/00014 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 2924/01013 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 2924/01087 Francium [Fr]
• 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 33/483 : Containers
• CPC Class Codes: H01L 33/642 : characterized by the shape
• CPC Class Codes: H05K 1/021 : Components thermally connected to metal substrates or heat-sinks by insert mounting
• CPC Class Codes: H05K 2201/0352 : Differences between the conductors of different layers of a multilayer
• CPC Class Codes: H05K 2201/0355 : Metal foils
• CPC Class Codes: H05K 2201/10106 : Light emitting diode [LED]
• CPC Class Codes: H05K 2203/049 : Wire bonding
• CPC Class Codes: H05K 2203/063 : of preperforated insulating layer
• CPC Class Codes: H05K 3/4084 : by deforming at least one of the conductive layers

Abstract

A semiconductor chip assembly includes a semiconductor device, a heat spreader, a conductive trace and an adhesive. The heat spreader includes a bump, a base and a flange. The conductive trace includes a pad and a terminal. The semiconductor device extends into a cavity in the bump, is electrically connected to the conductive trace and is thermally connected to the bump. The bump extends from the base into an opening in the adhesive, the base extends vertically from the bump opposite the cavity and the flange extends laterally from the bump at the cavity entrance. 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 an opening;

a heat spreader that includes a bump, a base and a flange, wherein (i) the bump is adjacent to the base and the flange, is integral with the flange, extends from the base in a first vertical direction and extends from the flange in a second vertical direction opposite the first vertical direction, (ii) the base extends from and covers the bump in the second vertical direction and extends laterally from the bump in lateral directions orthogonal to the vertical directions, (iii) the flange extends laterally from the bump and is spaced from the base, and (iv) a cavity in the bump faces in the first vertical direction, is covered by the bump in the second vertical direction, is spaced from the base by the bump and has an entrance at the flange;

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 semiconductor device extends into the cavity, is electrically connected to the pad and thereby electrically connected to the terminal, and is thermally connected to the bump and thereby thermally connected to the base;

wherein the adhesive contacts the bump, the base, the flange and the dielectric layer, is sandwiched between the bump and the dielectric layer, between the flange and the dielectric layer and between the base and the flange, extends laterally from the bump to or beyond the terminal and extends to peripheral edges of the assembly;

wherein the conductive trace is located outside the cavity;

wherein the bump extends into the opening and the aperture and covers the semiconductor device in the second vertical direction; and

wherein the cavity extends into the opening and the aperture.

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

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

4. The assembly of claim 1, wherein the adhesive contacts the conductive trace.

5. The assembly of claim 1, wherein the adhesive laterally covers and surrounds and conformally coats a sidewall of the bump.

6. The assembly of claim 1, wherein the adhesive conformally coats a surface portion of the base that is adjacent to and extends laterally from the bump and faces in the first vertical direction.

7. The assembly of claim 1, wherein the adhesive extends laterally from the bump beyond the conductive trace.

8. The assembly of claim 1, wherein the bump is coplanar with the adhesive at the base.

9. The assembly of claim 1, wherein the bump includes a first bent corner adjacent to the base and a second bent corner adjacent to the flange.

10. The assembly of claim 1, wherein the bump has an irregular thickness characteristic of stamping.

11. The assembly of claim 1, wherein the cavity extends across most of the bump in the vertical and lateral directions.

12. The assembly of claim 1, wherein the base has a first thickness where it is adjacent to the bump, a second thickness where it is adjacent to the dielectric layer that is larger than the first thickness and a flat surface that faces in the second vertical direction.

13. The assembly of claim 1, wherein the base covers the flange in the second vertical direction, extends laterally beyond the flange, supports the substrate and the adhesive and is spaced from the peripheral edges of the assembly.

14. The assembly of claim 1, wherein the flange and the pad have the same thickness and are coplanar with one another at a surface that faces in the first vertical direction.

15. The assembly of claim 1, wherein the base and the terminal have the same thickness where closest to one another, have different thickness where the base is adjacent to the bump and are coplanar with one another at a surface that faces in the second vertical direction.

16. The assembly of claim 1, wherein the pad and the terminal contact the adhesive, are spaced from the dielectric layer and extend beyond the adhesive and the dielectric layer in the first vertical direction.

17. The assembly of claim 1, wherein the pad contacts the adhesive, is spaced from the dielectric layer and extends beyond the adhesive and the dielectric layer in the first vertical direction, the terminal contacts the dielectric layer, is spaced from the adhesive and extends beyond the adhesive and the dielectric layer in the second vertical direction and the conductive trace includes a plated through-hole in an electrically conductive path between the pad and the terminal.

18. The assembly of claim 1, wherein the bump, the base, the flange, the pad and the terminal are the same metals.

19. The assembly of claim 1, wherein the bump, the base, the flange, the pad and the terminal include a gold, silver or nickel surface layer and a buried copper core and are primarily copper.

20. The assembly of claim 1, wherein the heat spreader includes a copper core shared by the bump, the base and the flange and the conductive trace includes a copper core shared by the pad and the terminal.

21. A semiconductor chip assembly, comprising:

a semiconductor device;

an adhesive that includes an opening;

a heat spreader that consists of a bump, a base and a flange, wherein (i) the bump is adjacent to the base and the flange, is integral with the flange, extends from the base in a first vertical direction and extends from the flange in a second vertical direction opposite the first vertical direction, (ii) the base extends from and covers the bump in the second vertical direction and extends laterally from the bump in lateral directions orthogonal to the vertical directions, (iii) the flange extends laterally from the bump and is spaced from the base, and (iv) a cavity in the bump faces in the first vertical direction, is covered by the bump in the second vertical direction, is spaced from the base by the bump and has an entrance at the flange;

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

a conductive trace that consists of a pad, a terminal and a plated through-hole, wherein the plated through-hole is an electrically conductive path between the pad and the terminal;

wherein the semiconductor device extends into the cavity, is electrically connected to the pad and thereby electrically connected to the terminal, and is thermally connected to the bump and thereby thermally connected to the base;

wherein the adhesive contacts the dielectric layer inside and outside the aperture, is sandwiched between the bump and the dielectric layer, between the bump and the plated through-hole, between the flange and the dielectric layer and between the base and the flange, extends laterally from the bump to or beyond the terminal and extends to peripheral edges of the assembly;

wherein the conductive trace is located outside the cavity, the pad contacts the adhesive, is spaced from the dielectric layer and extends beyond the adhesive and the dielectric layer in the first vertical direction, the terminal contacts the dielectric layer, is spaced from the adhesive and extends beyond the adhesive and the dielectric layer in the second vertical direction and the plated through-hole contacts and extends through the adhesive and the dielectric layer;

wherein the bump contacts the adhesive, is spaced from the dielectric layer, extends into the opening and the aperture, covers the semiconductor device in the second vertical direction and provides a recessed die paddle for the semiconductor device;

wherein the base contacts the adhesive and the dielectric layer, covers the flange in the second vertical direction, extends laterally beyond the flange and extends beyond the adhesive and the dielectric layer in the second vertical direction;

wherein the flange contacts the adhesive, is spaced from the dielectric layer and extends beyond the adhesive and the dielectric layer in the first vertical direction; and

wherein the cavity extends into the opening and the aperture and extends across most of the bump in the vertical and lateral directions.

22. The assembly of claim 21, wherein the semiconductor device is an LED chip, is located within the cavity, is electrically connected to the pad using a wire bond that extends within and outside the cavity and is thermally connected to the bump using a die attach that is located within the cavity.

23. The assembly of claim 21, wherein the adhesive alone can intersect an imaginary horizontal line between the bump and the dielectric layer, an imaginary horizontal line between the bump and the plated through-hole, an imaginary horizontal line between the bump and the base, an imaginary vertical line between the bump and the base, an imaginary vertical line between the pad and the dielectric layer, an imaginary vertical line between the flange and the dielectric layer and an imaginary vertical line between the flange and the base but the adhesive alone cannot intersect an imaginary line between the bump and the terminal, between the flange and the terminal, between the pad and the base or between the pad and the terminal.

24. The assembly of claim 21, wherein the bump is coplanar with the adhesive at the base, the flange is thicker than the base, the flange and the pad have the same thickness and are coplanar with one another at a surface that faces in the first vertical direction and the base and the terminal have the same thickness where closest to one another, have different thickness where the base is adjacent to the bump and are coplanar with one another at a surface that faces in the second vertical direction.

25. The assembly of claim 21, wherein the bump, the base, the flange, the pad, the terminal and the plated through-hole include a gold, silver or nickel surface layer and are primarily copper, the heat spreader includes a copper core shared by the bump, the base and the flange and the conductive trace includes a copper core shared by the pad, the terminal and the plated through-hole.

26. A semiconductor chip assembly, comprising:

a semiconductor device;

an adhesive that includes an opening;

a heat spreader that includes a bump, a base and a flange, wherein (i) the bump is adjacent to the base and the flange, is integral with the flange, extends from the base in a first vertical direction and extends from the flange in a second vertical direction opposite the first vertical direction, (ii) the base extends from the bump in the second vertical direction and extends laterally from the bump in lateral directions orthogonal to the vertical directions, (iii) the flange extends laterally from the bump and is spaced from the base, and (iv) a cavity in the bump faces in the first vertical direction, is covered by the bump in the second vertical direction, is spaced from the base by the bump and has an entrance at the flange; and

a conductive trace that includes a pad and a terminal;

wherein the base and the terminal have the same thickness where closest to one another, have different thickness where the base is adjacent to the bump and are coplanar with one another at a surface that faces in the second vertical direction;

wherein the semiconductor device extends into the cavity, is electrically connected to the pad and thereby electrically connected to the terminal, and is thermally connected to the bump and thereby thermally connected to the base;

wherein the adhesive contacts the bump, the base and the flange, is sandwiched between the base and the flange and extends laterally from the bump to or beyond the terminal;

wherein the conductive trace is located outside the cavity;

wherein the bump extends into the opening and covers the semiconductor device in the second vertical direction; and

wherein the cavity extends into the opening.

27. A semiconductor chip assembly, comprising:

an LED chip;

an adhesive that includes an opening;

a heat spreader that includes a bump, a base and a flange, wherein (i) the bump is adjacent to the base and the flange, is integral with the flange, extends from the base in a first vertical direction and extends from the flange in a second vertical direction opposite the first vertical direction, (ii) the base extends from the bump in the second vertical direction and extends laterally from the bump in lateral directions orthogonal to the vertical directions, (iii) the flange extends laterally from the bump and is spaced from the base, and (iv) a cavity in the bump faces in the first vertical direction, is covered by the bump in the second vertical direction, is spaced from the base by the bump and has an entrance at the flange;

a conductive trace that includes a pad and a terminal; and

an encapsulant;

wherein the bump is coplanar with the adhesive at the base, the flange and the pad have the same thickness and are coplanar with one another at a surface that faces in the first vertical direction and the base and the terminal have the same thickness where closest to one another, have different thickness where the base is adjacent to the bump and are coplanar with one another at a surface that faces in the second vertical direction;

wherein the LED chip is located within the cavity, is electrically connected to the pad and thereby electrically connected to the terminal, and is thermally connected to the bump and thereby thermally connected to the base;

wherein the encapsulant extends into the cavity and covers the LED chip in the first vertical direction;

wherein the adhesive contacts the bump, the base and the flange, is sandwiched between the base and the flange and extends laterally from the bump to or beyond the terminal;

wherein the conductive trace is located outside the cavity;

wherein the bump extends into the opening and covers the LED chip in the second vertical direction; and

wherein the cavity extends into the opening.

28. A semiconductor chip assembly, comprising:

an LED chip;

an adhesive that includes an opening;

a heat spreader that includes a bump, a base and a flange, wherein (i) the bump is adjacent to the base and the flange, is integral with the flange, extends from the base in a first vertical direction and extends from the flange in a second vertical direction opposite the first vertical direction, (ii) the base extends from and covers the bump in the second vertical direction and extends laterally from the bump in lateral directions orthogonal to the vertical directions, (iii) the flange extends laterally from the bump and is spaced from the base, and (iv) a cavity in the bump faces in the first vertical direction, is covered by the bump in the second vertical direction, is spaced from the base by the bump and has an entrance at the flange;

a conductive trace that includes a pad and a terminal; and

an encapsulant;

wherein the bump is coplanar with the adhesive at the base, the flange and the pad have the same thickness and are coplanar with one another at a surface that faces in the first vertical direction and the base and the terminal have the same thickness where closest to one another, have different thickness where the base is adjacent to the bump and are coplanar with one another at a surface that faces in the second vertical direction;

wherein the LED chip is located within the cavity, is electrically connected to the pad by a wire bond and thereby electrically connected to the terminal, and is thermally connected to the bump by a die attach and thereby thermally connected to the base;

wherein the encapsulant contacts the LED chip, the wire bond, the die attach and the bump in the cavity, is spaced from the conductive trace, the base and the adhesive and covers the LED chip in the first vertical direction;

wherein the adhesive contacts the bump, the base and the flange, is sandwiched between the base and the flange and extends laterally from the bump to or beyond the terminal;

wherein the die attach is located within the cavity, the wire bond extends within and outside the cavity and the conductive trace is located outside the cavity;

wherein the bump extends into the opening, covers the LED chip in the second vertical direction and provides a recessed die paddle and a reflector for the LED chip; and

wherein the cavity extends into the opening.