Semiconductor package capable of spreading heat

• US 5,397,917 A
• Filed: 04/26/1993
• Issued: 03/14/1995
• Est. Priority Date: 04/26/1993
• Status: Expired due to Term

• Current Assignee: Freescale Semiconductor, Inc. (NXP Semiconductors NV)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Tsai, Chi-Taou, Ommen, Denise M., Baird, John
• Primary Examiner(s): Hille, Rolf
• Assistant Examiner(s): Ostrowski, David
• Application Number:
  US08/051,954
• Time in Patent Office: 687 Days
• Field of Search: 257/686, 257/698, 257/700, 257/703, 257/706, 257/712, 257/720, 257/774, 257/668, 257/675, 257/702, 257/717, 257/778, 361/704, 361/707, 361/711, 361/717, 361/718, 361/719, 174/16.3
• US Class Current: 257/698
• CPC Class Codes: H01L 2224/05599 Material
• CPC Class Codes: H01L 2224/16 of an individual bump connector
• CPC Class Codes: H01L 2224/32245 the item being metallic
• 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 2224/73265 Layer and wire connectors
• CPC Class Codes: H01L 23/04 characterised by the shape of the container or parts, e.g. caps, walls
• CPC Class Codes: H01L 23/13 characterised by the shape
• CPC Class Codes: H01L 23/3121 a substrate forming part of the encapsulation
• CPC Class Codes: H01L 23/3672 Foil-like cooling fins or heat sinks being part of lead-frames H01L23/49568
• 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 24/73 Means for bonding being of different types provided for in two or more of groups H01L24/10, H01L24/18, H01L24/26, H01L24/34, H01L24/42, H01L24/50, H01L24/63, H01L24/71
• 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 2924/01078 Platinum [Pt]
• CPC Class Codes: H01L 2924/01079 Gold [Au]
• CPC Class Codes: H01L 2924/07802 not being an ohmic electrical conductor
• CPC Class Codes: H01L 2924/09701 : Low temperature co-fired ceramic [LTCC]
• CPC Class Codes: H01L 2924/15153 : the die mounting substrate comprising a recess for hosting the device
• CPC Class Codes: H01L 2924/1517 : Multilayer substrate
• CPC Class Codes: H01L 2924/15311 : being a ball array, e.g. BGA
• CPC Class Codes: H01L 2924/16152 : Cap comprising a cavity for hosting the device, e.g. U-shaped cap
• CPC Class Codes: H01L 2924/1616 : Cavity shape
• CPC Class Codes: H01L 2924/30107 : Inductance
• CPC Class Codes: H01L 2924/3011 : Impedance

Abstract

A package (10, 37, 39) capable of spreading heat from a semiconductor die (25). The package (10, 37) includes a heat spreader (11) having a thickness of approximately 0.2 millimeters and a plurality of heat spreader clearance holes (16). The heat spreader (11) is coated with an adhesive material (17) which fills the plurality of heat spreader clearance holes (16). A substrate layer (18) is formed on the adhesive material (17). The substrate layer (18) has conductive traces (20, 24) and conductive pads (21) disposed thereon. A cavity (23) may be present in the package (10, 37, 39) which exposes a portion of the heat spreader (11) and is adapted to receive the semiconductor die (25). The cavity (23) is covered by a cavity sealing means (30, 38).

Claims

1. A semiconductor package capable of spreading heat, comprising:

a heat spreader having a first surface, a second surface, and a plurality of clearance holes extending therethrough, each clearance hole having a diameter;

an adhesive material coating the first and second surfaces;

a substrate layer, the substrate layer covering the adhesive material;

a top-side conductive trace, the tope-side conductive trace over the first surface;

a bottom-side conductive trace, the bottom-side conductive trace over the second surface;

a plurality of signal vias, each of the plurality of signal vias within a corresponding clearance hole and spaced apart from edges of the corresponding clearance hole by the adhesive material;

a conductive pad, the conductive pad over the second surface and electrically coupled to the top-side conductive trace via the bottom-side conductive trace and at least one of the plurality of signal vias;

a cavity for receiving a semiconductor die, the cavity exposing the first surface of the heat spreader; and

a material for covering the cavity for receiving the semiconductor die.

2. A semiconductor package capable of spreading heat as claimed in claim 1, wherein the adhesive material is a combination of a reinforcement fiber and a resin.

3. A semiconductor package capable of spreading heat as claimed in claim 1, wherein the material for covering is a bi-metal laminated cap comprising a layer of aluminum and a layer of iron.

4. A semiconductor package capable of spreading heat as claimed in claim 1, wherein the materials for covering is shaped to facilitate heat removal and contoured to cover a conductive wire coupling the semiconductor die to the top-side conductive trace, the material for covering electrically isolated from the conductive wire.

5. A semiconductor package capable of spreading heat as claimed in claim 1, wherein the material for covering comprises a mold compound.

6. A semiconductor package capable of spreading heat as claimed in claim 1, wherein the heat spreader has a thickness of approximately 0.2 millimeters.

7. A semiconductor package capable of spreading heat as claimed in claim 1, wherein the clearance holes are formed in a radial array.

8. A semiconductor package capable of spreading heat as claimed in claim 3, wherein the material for covering has a coefficient of thermal expansion that matches the coefficient of thermal expansion of the combination of the adhesive material coating the first and second surfaces and the substrate layer covering the adhesive material.

9. A heat spreader package comprising:

a heat spreader of substantially 0.2 millimeters thickness positioned in a multi-layer board having a top side and a bottom side;

electrically isolated vias in the heat spreader for providing electrical connection through the heat spreader;

semiconductor die receiving means, wherein the semiconductor die receiving means is on the top side of the multi-layer board and comprises a cavity exposing a portion of the heat spreader and the semiconductor die is attached to the portion of the heat spreader that is exposed by a die attach material;

semiconductor die mounted on the semiconductor die receiving means; and

means for protectively covering the semiconductor die.

10. The heat spreader package as claimed in claim 9 wherein the electrically isolated vias are electrically isolated from the heat spreader by an adhesive material comprising a reinforcement fiber and a resin.

11. A heat spreader package as claimed in claim 9, wherein the diameter of the electrically isolated vias is approximately 0.3 millimeters.

12. A heat spreader package as claimed in claim 9, wherein the means for protectively covering the semiconductor die comprises a metal cap.

13. A heat spreader package as claimed in claim 9, wherein the means for protectively covering the semiconductor die comprises a molded plastic body.

14. A heat spreader package as claimed in claim 9, wherein the semiconductor die receiving means comprises pads to which the semiconductor die is flip-chip bonded.

15. A heat spreader package as claimed in claim 9, wherein the means for protectively covering the semiconductor die has a coefficient of thermal expansion that matches the coefficient of thermal expansion of the multi-layer board.