Heat sink formed with conformal shield

• US 8,434,220 B2
• Filed: 12/07/2007
• Issued: 05/07/2013
• Est. Priority Date: 06/27/2007
• Status: Active Grant

• Current Assignee: Qorvo US, Inc. (Qorvo, Inc.)
• Original Assignee: RF Micro Devices Incorporated (Qorvo, Inc.)
• Inventors: Rao, Jayanti Jaganatha, Morris, Thomas Scott, Shah, Milind
• Primary Examiner(s): ANGWIN, DAVID PATRICK
• Application Number:
  US11/952,617
• Publication Number:
  US 20090000114A1
• Time in Patent Office: 1,978 Days
• Field of Search: 298/32, 298/31, 298/41, 298/46, 298/54, 298/55, 361/816, 361/818, 257/659, 257/660, 174/350
• US Class Current: 29/832
• CPC Class Codes: H01L 23/552 Protection against radiation, e.g. light or electromagnetic waves
• CPC Class Codes: H01L 24/97 the devices being connected to a common substrate, e.g. interposer, said common substrate being separable into individual assemblies after connecting
• CPC Class Codes: H01L 25/0655 the devices being arranged next to each other
• CPC Class Codes: H01L 2924/01005 Boron [B]
• CPC Class Codes: H01L 2924/01006 Carbon [C]
• CPC Class Codes: H01L 2924/01013 Aluminum [Al]
• CPC Class Codes: H01L 2924/01016 Sulfur [S]
• CPC Class Codes: H01L 2924/01018 Argon [Ar]
• CPC Class Codes: H01L 2924/01029 Copper [Cu]
• CPC Class Codes: H01L 2924/0103 Zinc [Zn]
• CPC Class Codes: H01L 2924/01033 Arsenic [As]
• CPC Class Codes: H01L 2924/01046 Palladium [Pd]
• CPC Class Codes: H01L 2924/01047 Silver [Ag]
• CPC Class Codes: H01L 2924/01078 Platinum [Pt]
• CPC Class Codes: H01L 2924/01079 Gold [Au]
• CPC Class Codes: H01L 2924/01082 Lead [Pb]
• CPC Class Codes: H01L 2924/014 Solder alloys
• CPC Class Codes: H01L 2924/12041 LED
• CPC Class Codes: H01L 2924/14 Integrated circuits
• CPC Class Codes: H01L 2924/1815 Shape
• CPC Class Codes: H01L 2924/3025 : Electromagnetic shielding
• CPC Class Codes: H05K 1/0218 : by printed shielding conductors, ground planes or power plane H05K1/0236 takes precedence
• CPC Class Codes: H05K 2203/0723 : Electroplating, e.g. finish plating
• CPC Class Codes: H05K 3/0052 : Depaneling, i.e. dividing a panel into circuit boards; Working of the edges of circuit boards
• CPC Class Codes: H05K 3/181 : by electroless plating adhesives therefor H05K3/387
• CPC Class Codes: H05K 3/284 : for encapsulating mounted components H05K1/185 takes precedence
• CPC Class Codes: Y10T 29/49 : Method of mechanical manufacture
• CPC Class Codes: Y10T 29/49002 : Electrical device making
• CPC Class Codes: Y10T 29/49117 : Conductor or circuit manufacturing
• CPC Class Codes: Y10T 29/49124 : On flat or curved insulated base, e.g., printed circuit, etc.
• CPC Class Codes: Y10T 29/49126 : Assembling bases
• CPC Class Codes: Y10T 29/49128 : Assembling formed circuit to base
• CPC Class Codes: Y10T 29/4913 : Assembling to base an electrical component, e.g., capacitor, etc.
• CPC Class Codes: Y10T 29/49131 : by utilizing optical sighting device
• CPC Class Codes: Y10T 29/49144 : by metal fusion
• CPC Class Codes: Y10T 29/49146 : with encapsulating, e.g., potting, etc.
• CPC Class Codes: Y10T 29/49153 : with shaping or forcing terminal into base aperture
• CPC Class Codes: Y10T 29/49155 : Manufacturing circuit on or in base
• CPC Class Codes: Y10T 29/49204 : Contact or terminal manufacturing
• CPC Class Codes: Y10T 29/49789 : Obtaining plural product pieces from unitary workpiece

Abstract

In one embodiment, a meta-module having circuitry for two or more modules is formed on a substrate, which is preferably a laminated substrate. The circuitry for the different modules is initially formed on the single meta-module. Each module will have one or more component areas in which the circuitry is formed. A metallic structure is formed on or in the substrate for each component area to be shielded. A single body, such as an overmold body, is then formed over all of the modules on the meta-module. At least a portion of the metallic structure for each component area to be shielded is then exposed through the body by a cutting, drilling, or like operation. Next, an electromagnetic shield material is applied to the exterior surface of the body of each of the component areas to be shielded and in contact with the exposed portion of the metallic structures.

Claims

1. A method of manufacturing a module comprising:

providing a laminate;

providing an electronic component on a component area on an upper surface of the laminate;

providing a metallic layer grid on the upper surface of the laminate, wherein the metallic layer grid includes a peripheral metallic structure that is peripheral to the component area and substantially encircles the component area;

forming an overmold body fully covering the electronic component and the peripheral metallic structure;

exposing a portion of the top surface of the electronic component by removing a first portion of the overmold body;

exposing a portion of the top surface of the peripheral metallic structure by removing a second portion of the overmold body; and

forming an electromagnetic shield covering the overmold body, wherein the electromagnetic shield contacts the exposed portion of the electronic component and contacts the exposed portion of the peripheral metallic structure, and wherein the electronic component is configured to sink heat directly to the electromagnetic shield through the contacted exposed portion of the electronic component.

2. The method of claim 1 wherein the substrate further comprises heat sink vias, which are in thermal contact with the first electronic components.

3. The method of claim 2 wherein the substrate further comprises conductors for connecting the heat sink vias with the electromagnetic shields.

4. The method of claim 1 wherein the certain component areas further comprise second electronic components that are covered by the body and are not in contact with the electromagnetic shields.

5. The method of claim 4 wherein the substrate further comprises heat sink vias, which are in thermal contact with the first electronic components.

6. The method of claim 4 wherein the substrate further comprises heat sink vias, which are in thermal contact with the second electronic components.

7. The method of claim 1 wherein the body is formed by uniformly covering the component areas for the plurality of modules with the dielectric material, such that the body is initially a single, continuous element that covers all of the plurality of component areas prior to exposing the exposed metallic structures.

8. The method of claim 1 wherein the metallic structures extend substantially about a periphery of each of the certain component areas.

9. The method of claim 8 wherein each of the metallic structures comprises a continuous metal trace on the top surface of the substrate and extending substantially about the periphery of each of the certain component areas.

10. The method of claim 8 wherein each of the metallic structures comprises a discontinuous metal trace on the top surface of the substrate and extending substantially about the periphery of each of the certain component areas.

11. The method of claim 8 wherein each of the metallic structures comprises a series of segments on the top surface of the substrate and extending substantially about the periphery of each of the certain component areas.

12. The method of claim 1, wherein mechanical drilling is used to expose the portion of the top surface of the electronic component.

13. The method of claim 1, wherein a laser is used to expose the portion of the top surface of the electronic component.

14. The method of claim 1, wherein mechanical drilling is used to expose the portion of the top surface of the peripheral metal structure.

15. The method of claim 1, wherein a laser is used to expose the portion of the top surface of the peripheral metal structure.

16. The method of claim 1, further comprising creating a sealing structure on a bottom surface of the laminate, wherein the sealing structure is configured to substantially encircle a periphery of the bottom surface of the laminate, to form a seal with a carrier medium, and to seal out undesired chemicals during formation of the module.

17. The method of claim 1, wherein the peripheral metallic structure includes at least one portion which has been built up in height by one of a plate and a surface mount prior to forming the overmold body.

18. The method of 16, further comprising forming a support structure on a bottom surface of the laminate in an area directly below the portion of the peripheral metallic structure which will be exposed.

19. The method of claim 18, wherein the support structure has the shape of a rail.

20. The method of claim 18, wherein the support structure has the shape of a pillar.

21. The method of claim 18, wherein the support structure has the shape of a grid.

22. A method of manufacturing a module comprising:

a) providing a laminate;

b1) providing an electronic component on a component area on an upper surface of the laminate;

b2) providing a metallic layer grid on the upper surface of the laminate, wherein the metallic layer grid includes a peripheral metallic structure that is peripheral to the component area and substantially encircles the component area;

c) forming an overmold body fully covering the electronic component and the peripheral metallic structure;

d1) exposing a portion of the top surface of the electronic component by removing a first portion of the overmold body;

d2) exposing a portion of the top surface of the peripheral metallic structure by removing a second portion of the overmold body; and

e) forming an electromagnetic shield covering the overmold body, wherein the electromagnetic shield contacts the exposed portion of the electronic component and contacts the exposed portion of the peripheral metallic structure, and wherein the electronic component is configured to sink heat directly to the electromagnetic shield through the contacted exposed portion of the electronic component, and

wherein step a) is performed first;

then steps b1) and b2) are performed next in any order or simultaneously;

then step c) is performed;

then steps d1) and d2) are performed next in any order or simultaneously; and

then step e) is performed,

wherein the metallic layer grid is provided by providing a metal trace and by providing the peripheral metallic structure directly on top of the metal trace,

wherein the peripheral metallic structure includes at least one plating layer or includes at least one surface mount structure, and

wherein the peripheral metallic structure is configured to provide electromagnetic shielding around the perimeter of the component area.