Encapsulated microelectromechanical (MEMS) devices

• US 6,472,739 B1
• Filed: 11/15/1999
• Issued: 10/29/2002
• Est. Priority Date: 11/15/1999
• Status: Expired due to Term

• Current Assignee: Memscap Incorporated
• Original Assignee: JDS Uniphase Corporation (Lumentum Holdings Inc.)
• Inventors: Wood, Robert L., Dudley, Bruce W.
• Primary Examiner(s): Talbott, David L.
• Assistant Examiner(s): Chambliss, Alonzo
• Application Number:
  US09/441,190
• Time in Patent Office: 1,079 Days
• Field of Search: 438/15, 438/106, 438/125, 438/126, 438/127, 257/414, 257/415, 257/704, 257/787, 257/788, 257/793, 257/729, 257/730, 335/128, 174/52.2, 174/52.3, 174/52.4, 361/760
• US Class Current: 257/704
• CPC Class Codes: B81C 1/00333 Aspects relating to packaging of MEMS devices, not covered by groups B81C1/00269 - B81C1/00325
• CPC Class Codes: B81C 2203/0136 Growing or depositing of a covering layer

Abstract

A method of encapsulating microelectromechanical (MEMS) structures is provided wherein the MEMS structures are formed on a substrate and encapsulated prior to packaging thereof. A sacrificial material is first deposited over the substrate to cover at least a portion of the MEMS structure. An encapsulation material is then deposited over the sacrificial material such that the encapsulation material covers at least a portion of the sacrificial material over the MEMS structure. The sacrificial material is subsequently removed such that the encapsulation material forms a shell spaced apart from and covering the MEMS structure and permits the intended operation of the MEMS structure. Associated MEMS devices fabricated using a method of encapsulating MEMS structures according to embodiments of the present invention are also provided.

Claims

1. An intermediate microelectromechanical (MEMS) device including a movable portion comprising:

a microelectronic substrate having at least one MEMS device thereon;

a sacrificial layer over the substrate that is directly on the movable portion of the MEMS device; and

an encapsulating layer that is formed of an epoxy material and that is connected to the sacrificial layer that is directly on the movable portion of the sacrificial layer over the MEMS device and is connected to the microelectronic substrate.

2. An intermediate MEMS device according to claim 1 wherein the microelectronic substrate defines anchor points for the encapsulating layer, the anchor points being fixed in location.

3. An intermediate MEMS device according to claim 2 wherein said encapsulating layer comprises a shell having supports connected to the microelectronic substrate at the anchor points.

4. An intermediate MEMS device according to claim 1 wherein the encapsulating layer is comprised of an epoxy material.

5. An intermediate MEMS device according to claim 1 in combination with an operational device that is connected thereto, wherein the MEMS device includes an input that is configured to be responsive to the operational device, and an output that is configured to be supplied to the operational device.

6. An intermediate MEMS device according to claim 5, wherein the operational device comprises at least one of the high voltage switch, a gyroscope and an inertia sensor.

7. An intermediate MEMS device according to claim 5, wherein the operational device is configured to at least one of directing light and controlling air flow.

8. An intermediate MEMS device according to claim 1 wherein the sacrificial layer is sufficiently thick between the movable portion of the MEMS device and the encapsulating layer that is adjacent thereto, such that the MEMS device moves without interference from the encapsulating layer upon removal of the sacrificial layer between the MEMS device and the encapsulating layer that is adjacent thereto.