Package having MEMS element and fabrication method thereof

• US 8,653,661 B2
• Filed: 06/28/2011
• Issued: 02/18/2014
• Est. Priority Date: 05/12/2011
• Status: Expired due to Fees

• Current Assignee: Siliconware Precision Industries Co., Ltd. (ASE Technology Holding Co., Ltd.)
• Original Assignee: Siliconware Precision Industries Co., Ltd. (ASE Technology Holding Co., Ltd.)
• Inventors: Chan, Chang-Yueh, Huang, Chien-Ping, Ke, Chun-Chi, Chiu, Shih-Kuang
• Primary Examiner(s): Maldonado, Julio J
• Assistant Examiner(s): Oh, Jaehwan
• Application Number:
  US13/170,424
• Publication Number:
  US 20120286425A1
• Time in Patent Office: 966 Days
• Field of Search: 257/777
• US Class Current: 257/738
• CPC Class Codes: B81B 2207/096 through the substrate
• CPC Class Codes: B81C 1/00301 Connecting electric signal lines from the MEMS device with external electrical signal lines, e.g. through vias
• CPC Class Codes: H01L 2224/16225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• 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 2224/48465 the other connecting portion not on the bonding area being a wedge bond, i.e. ball-to-wedge, regular stitch
• 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 2924/1461 MEMS
• CPC Class Codes: H01L 2924/15311 being a ball array, e.g. BGA
• CPC Class Codes: H01L 2924/181 Encapsulation

Abstract

A package structure having an MEMS element is provided, which includes: a protection layer having openings formed therein; conductors formed in the openings, respectively; conductive pads formed on the protection layer and the conductors; a MEMS chip disposed on the conductive pads; and an encapsulant formed on the protection layer for encapsulating the MEMS chip. By disposing the MEMS chip directly on the protection layer to dispense with the need for a carrier, such as a wafer or a circuit board that would undesirably add to the thickness, the present invention reduces the overall thickness of the package to thereby achieve miniaturization.

Claims

1. A package having a Micro-Electro-Mechanical System (MEMS) element, comprising:

a protection layer having opposite first and second surfaces and a plurality of openings in communication with the first and second surfaces;

a plurality of conductors formed in the openings of the protection layer, respectively, wherein each of the conductors has opposite third and fourth surfaces, and the fourth surface of each of the conductors is flush with the second surface of the protection layer;

a plurality of conductive pads formed on the first surface of the protection layer and the third surface of each of the conductors, for electrically connecting with the conductors, wherein the conductive pads are free from being formed on the fourth surface of each of the conductors;

a plurality of conductive bumps disposed on the conductive pads and electrically connected to the conductive pads;

a MEMS chip disposed on the conductive bumps and electrically connected to the conductive pads by the conductive bumps; and

an encapsulant formed on the protection layer for encapsulating the MEMS chip, wherein the fourth surface of each of the conductors is exposed from the second surface of the protection layer and the encapsulant.

2. The package of claim 1, wherein the protection layer is made of a non-conductive material.

3. The package of claim 1, wherein the conductors are made of copper.

4. The package of claim 1, further comprising a plurality of solder balls disposed on the fourth surface of each of the conductors, respectively.

5. The package of claim 1, further comprising a solder mask layer formed on the first surface of the protection layer and having a plurality of openings through which the conductive pads are exposed so as for the MEMS chip to be disposed thereon.

6. The package of claim 5, wherein the encapsulant is formed on the solder mask layer.

7. The package of claim 1, wherein the conductive bumps are made of gold or a solder material.

8. A fabrication method of a package having a MEMS element, comprising the steps of:

forming on a carrier a protection layer having opposite first and second surfaces in a manner that the protection layer is attached to the carrier via the second surface thereof, and forming in the protection layer a plurality of openings in communication with the first and second surfaces for exposing portions of the carrier;

forming a plurality of conductors in the openings of the protection layer, respectively, wherein each of the conductors has opposite third and fourth surfaces, and the fourth surface of each of the conductors is in contact with the carrier;

forming a plurality of conductive pads on the first surface of the protection layer and the third surface of each of the conductors, respectively, so as for the conductors to be electrically connected to the conductive pads;

disposing a MEMS chip on the conductive pads and electrically connecting the MEMS chip to the conductive pads;

forming an encapsulant on the first surface of the protection layer for encapsulating the MEMS chip; and

removing the carrier to expose the fourth surface of each of the conductors from the second surface of the protection layer.

9. The method of claim 8, wherein the carrier is a metal plate.

10. The method of claim 8, wherein the protection layer is made of a non-conductive material.

11. The method of claim 8, wherein the conductors are made of copper.

12. The method of claim 8, further comprising disposing a plurality of solder balls on exposed surfaces of the conductors, respectively.

13. The method of claim 8, before disposing the MEMS chip, further comprising forming a solder mask layer on the first surface of the protection layer and forming a plurality of openings in the solder mask layer for exposing the conductive pads, respectively.

14. The method of claim 13, wherein the encapsulant is formed on the solder mask layer such that the solder mask layer is positioned between the encapsulant and the protection layer.

15. The method of claim 8, further comprising forming conductive bumps on the conductive pads for electrically connecting the MEMS chip to the conductive pads.

16. The method of claim 15, wherein the conductive bumps are made of gold or a solder material.

17. The method of claim 8, wherein the MEMS chip has conductive bumps disposed thereon so as for the MEMS chip to be disposed on the conductive pads via the conductive bumps.

18. The method of claim 17, wherein the conductive bumps are made of gold or a solder material.