REINFORCED MICRO-ELECTROMECHANICAL SYSTEM PACKAGE STRUCTURE

Abstract

The present invention discloses a reinforced MEMS package structure, wherein after the wire-bonding process and before the molding process, an extra resin coating process is used to apply a protective resin onto the MEMS chip, the controller chip, the wires and a portion of the lead frame and provide an extra protection for the MEMS structure lest the MEMS structure be damaged by stress, thermal stress, or external force. Thereby, a reinforced MEMS package structure with a higher strength and a smaller size is achieved.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. In the drawings:

FIG. 1 is a diagram schematically showing a conventional MEMS package structure; and

FIG. 2 is a diagram schematically showing the reinforced MEMS package structure according to one embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers are used in the drawings and the description to refer to the same or like parts.

The present invention is based on the current packaging processes, such as the processes of dicing, chip attachment, wire bonding and molding, but a resin coating process is undertaken to cover the chips, wires and a portion of the lead frame with a protective resin after the wire-bonding process and before the molding process. After the resin coating process is done, the succeeding processes, such as the molding process, are undertaken to complete the reinforced package structure.

Refer to FIG. 2 a diagram schematically showing the reinforced MEMS package structure according to one embodiment of the present invention. As shown in FIG. 2, the reinforced MEMS package structure comprises: a MEMS chip 20; a controller chip 22 providing driving signal for the MEMS chip 20; a lead frame 24; a protective resin 30 and an encapsulant 28. The MEMS chip 20 is electrically connected to the inner leads 242 of the lead frame 24 with wires 26. The controller chip 22 is respectively electrically connected to the MEMS chip 20 and the inner leads 242 with wires 26. A protective resin 30 is used to cover the MEMS chip 20, the controller chip 22, the wires 26 and the inner leads 242 of the lead frame 24 and provide an extra protection for the abovementioned elements, and the entire structure is thus reinforced. The material of the protective resin 30 may be an epoxy, silicon or the like, which is compatible with the materials of the MEMS chip 20, the controller chip 22, the wires 26 and the lead frame 24. Then, an encapsulant 28 covers the protective resin 30, the bottom of the MEMS chip 20 and the inner leads 242 with the outer leads 244 of the lead frame 24 exposed. The material of the encapsulant 28 may be an epoxy.

In summary, the present invention utilizes an extra resin coating process to apply a protective resin, which functions as a buffering material to absorb stress, onto the MEMS structure before the molding process lest the MEMS structure be damaged by stress, thermal stress, or external force. Thereby, a reinforced MEMS package structure with a higher strength and a smaller size is achieved.

It will be apparent to those skilled in the art that various modifications and variations can be made to the present invention without departing from the scope or spirit of the invention. In view of the foregoing, it is intended that the present invention cover modifications and variations of this invention provided they fall within the scope of the invention and its equivalent.

Claims

1. A reinforced micro-electromechanical system (MEMS) package structure, comprising: a lead frame;a MEMS chip electrically connected to said lead frame with wires;a controller chip respectively electrically connected to said MEMS chip and said lead frame with wires and providing driving signal for said MEMS chip;a protective resin covering said MEMS chip, said controller chip, said wires and a portion of said lead frame; andan encapsulant covering said protective resin, said MEMS chip and a portion of said lead frame.

2. The reinforced MEMS package structure according to claim 1, wherein material of said protective resin is an epoxy or silicon.

3. The reinforced MEMS package structure according to claim 1, wherein material of said encapsulant is an epoxy.

4. The reinforced MEMS package structure according to claim 1, wherein said lead frame has inner leads and outer leads.

5. The reinforced MEMS package structure according to claim 4, wherein said wires are connected to said inner leads, and said outer leads are exposed in exterior of said encapsulant.