Multi-layer thin-film coatings for system-in-package assemblies in portable electronic devices

• US 9,949,359 B2
• Filed: 06/18/2014
• Issued: 04/17/2018
• Est. Priority Date: 03/18/2014
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Chen, Yanfeng, Pennathur, Shankar S.
• Primary Examiner(s): Tran, Binh
• Application Number:
  US14/308,463
• Publication Number:
  US 20150271911A1
• Time in Patent Office: 1,399 Days
• Field of Search: 361760, 361761, 361762, 361765, 361777, 361816, 361818, 174521
• CPC Class Codes: H01L 2924/3025 Electromagnetic shielding
• CPC Class Codes: H05K 1/0216 Reduction of cross-talk, noise or electromagnetic interference grounding H05K1/0215
• CPC Class Codes: H05K 1/0218 by printed shielding conductors, ground planes or power plane H05K1/0236 takes precedence
• CPC Class Codes: H05K 1/18 Printed circuits structurally associated with non-printed electric components H05K1/0201, H05K1/023, H05K1/0243, and H05K1/16 take precedence
• CPC Class Codes: H05K 2201/09972 Partitioned, e.g. portions of a PCB dedicated to different functions; Boundary lines therefore; Portions of a PCB being processed separately or differently
• CPC Class Codes: H05K 2201/10371 Shields or metal cases
• CPC Class Codes: H05K 2203/1322 Encapsulation comprising more than one layer
• CPC Class Codes: H05K 3/284 for encapsulating mounted components H05K1/185 takes precedence
• CPC Class Codes: H05K 3/30 Assembling printed circuits with electric components, e.g. with resistor
• CPC Class Codes: H05K 9/00 Screening of apparatus or components against electric or magnetic fields devices for absorbing radiation from an antenna H01Q17/00
• CPC Class Codes: H05K 9/0081 Electromagnetic shielding materials, e.g. EMI, RFI shielding H05K9/0003 takes precedence
• CPC Class Codes: Y10T 29/49146 with encapsulating, e.g., potting, etc.

Abstract

A portable electronic device packaged into a System-in-Package assembly is disclosed. The portable electronic device can include a substrate and a plurality of components mounted on the substrate and included in one or more subsystems. Interference between subsystems or from external sources can be reduced or eliminated by disposing an insulating layer over the components, forming narrow trenches between subsystems, and depositing one or more layers of a multi-layer thin film stack on the insulating layer and filling the trenches. In some examples, the multi-layer thin film stack can include an adhesion layer, a shielding layer, a protection layer, and a cosmetic layer. In some examples, the multi-layer thin film stack can include multi-functional layers such as a protection and cosmetic layer.

Claims

1. An electronic device, comprising:

a substrate; and

a system in package assembly including;

a plurality of electronic components mounted on the substrate,

one or more subsystems, each subsystem including two or more of the plurality of electronic components, each subsystem separated from an adjacent subsystem by one of a plurality of trenches, and each subsystem including an insulating layer surrounding the electronic components and forming substantially parallel walls of the plurality of trenches, and

a multi-layer thin film stack disposed in the plurality of trenches and conformally coating at least sides of the one or more subsystems, the multi-layer thin film stack including;

an adhesion layer disposed on the insulating layer,

a cosmetic layer, and

a shielding layer configured to shield the one or more subsystems from interference,

wherein at least two layers of the multi-layer thin film stack contact the substrate within the plurality of trenches and at least one of the layers of the multi-layer thin film stack has a first portion parallel to the substrate and traversing one of the plurality of trenches and a second portion perpendicularly intersecting the substrate and the first portion.

2. The electronic device of claim 1,

wherein the plurality of trenches are formed in the insulating layer, wherein a width of each of the plurality of trenches is between 10-100 microns.

3. The electronic device of claim 1, wherein the multi-layer thin film stack further comprises a protection layer.

4. The electronic device of claim 3, wherein the protection layer is stainless steel.

5. The electronic device of claim 1, wherein the adhesion layer is made of stainless steel.

6. The electronic device of claim 1, wherein a thickness of the adhesion layer is between 10-100 nm.

7. The electronic device of claim 1, wherein the shielding layer includes at least one of copper, nickel, and silver.

8. The electronic device of claim 1, wherein a thickness of the shielding layer is between 1-100 microns.

9. The electronic device of claim 1, wherein the cosmetic layer is at least one of Titanium Nitride (TiN), Gold (Au), Zirconium Nitride (ZrN), Diamond-like Carbon (DLC), Boron Carbide (B₄C), Molybdenum Disulfide (MoS₂), Aluminum Titanium Nitride (AlTiN), AlTiN/(Mo,W)S₂, Silicon Carbide (SiC), Chromium Nitride (CrN), Titanium Carbide (TiC), TiC/(Mo,W)S₂, Silver (Ag), Titanium Nitride (TiN) and Titanium Carbon Nitride (TiCN).

10. The electronic device of claim 1, wherein a thickness of the cosmetic layer is between 100-1000 nanometers.

11. The electronic device of claim 1, wherein the multi-layer thin film stack comprises a multi-functional layer, the multi-functional layer is at least one of Silicon Carbide (SiC), Diamond like Carbon (DLC), Molybdenum Sulfide (MoS₂), Aluminum Titanium Nitride (AlTiN), Boron Carbide (B₄C), AlTiN/(Mo,W)S₂, Titanium Nitride (TiN), Titanium Carbide (TiC), Chromium Nitride (CrN), and Zirconium Nitride (ZrN).

12. The electronic device of claim 1, wherein the cosmetic layer is a multi-functional layer configured as both a cosmetic layer and a protection layer.

13. The electronic device of claim 12, wherein a thickness of the multi-functional layer is between 100-1000 nm.

14. The electronic device of claim 1, wherein at least two layers of the multi-layer thin film stack are located between the walls of each trench and at least one layer of the multi-layer thin-film stack is located outside the walls of each trench.

15. The electronic device of claim 1, wherein at least one of layer of the multi-layer thin film stack is located between walls of each trench and includes a top surface that forms a planar surface.

16. The electronic device of claim 1, wherein the at least two layers contacting the substrate within the plurality of trenches includes the adhesion layer disposed on two adjacent subsystems and the shielding layer.