FUNCTIONAL ELEMENT PACKAGE AND FABRICATION METHOD THEREFOR

• US 20100072562A1
• Filed: 03/17/2008
• Published: 03/25/2010
• Est. Priority Date: 03/19/2007
• Status: Active Grant

• Current Assignee: Fraunhofer Gesellschaft Zur Foerderung Der Angewandten Forsching E.V., Ricoh Company Limited
• Original Assignee: Fraunhofer Gesellschaft Zur Foerderung Der Angewandten Forsching E.V., Ricoh Company Limited
• Inventors: Sato, Yukito, Froemel, Joerg
• Granted Patent: US 8,164,180 B2
• Time in Patent Office: Days
• US Class Current: 257/415
• CPC Class Codes: B81B 2207/095 through the lid
• CPC Class Codes: B81B 2207/097 Interconnects arranged on the substrate or the lid, and covered by the package seal
• CPC Class Codes: B81B 2207/098 Arrangements not provided for in groups B81B2207/092 - B81B2207/097
• 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: B81C 2203/019 characterised by the material or arrangement of seals between parts
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 23/04 characterised by the shape of the container or parts, e.g. caps, walls
• CPC Class Codes: H01L 23/10 characterised by the material or arrangement of seals between parts, e.g. between cap and base of the container or between leads and walls of the container
• 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 2924/00014 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 2924/01079 Gold [Au]
• CPC Class Codes: H01L 2924/1461 MEMS
• CPC Class Codes: H01L 2924/3011 Impedance

Abstract

A functional element package includes a silicon substrate with a functional element having one of a mobile portion and a sensor thereon; a seal member being bonded with the silicon substrate to form an airtightly sealed space therein, and including a step portion in its height direction; a first wiring portion being connected with the functional element and extending from the airtightly sealed space to an outside thereof; a second wiring portion being different from the first wiring portion and extending from the step portion to an upper surface of the seal member; and a bump on the second wiring portion, in which the first wiring portion is bent towards the airtightly sealed space and connected via a photoconductive member with the second wiring portion on the step portion.

Claims

1. A functional element package comprising:

a silicon substrate (41a) on which a functional element is formed, the functional element having one of a mobile portion (42) and a sensor;

a seal member (43) being bonded with the silicon substrate (41a) to airtightly seal the functional element and form an airtightly sealed space (43a) therein, and including a step portion (43c) in its height direction;

a first wiring portion (44) being connected with the functional element and extending from the airtightly sealed space (43a) to an outside thereof;

a second wiring portion (46) being different from the first wiring portion (44) and extending from the step portion (43c) to an upper surface (43′

) of the seal member (43); and

a bump (48) on the second wiring portion (46) on the upper surface (43′

) of the seal member (43), wherein

the first wiring portion (44) extending in the outside is bent towards the airtightly sealed space (43a) and connected via a photoconductive member with the second wiring portion (46) on the step portion (43c).

2. A functional element package according to claim 1, wherein the photoconductive member is a bonding wire (47).

3. A functional element package according to claim 2, wherein the seal member (43) has an inclined peripheral wall from the upper surface (43′

) to the step portion (43c).

4. A functional element package according to claim 2, wherein the seal member (43) has an inclined peripheral wall from the upper surface (43′

) to the step portion (43c), and a vertical peripheral wall from the step portion (43c) to an upper exposed portion (44′

) of the first wiring portion (44).

5. A functional element package according to claim 2, wherein the step portion (43c) is formed at end of the seal member (43).

6. A functional element package according to claim 2, wherein:

the seal member (43) has a through hole (43b); and

the step portion (43c) is formed around the through hole (43b).

7. A functional element package according to claim 6, wherein:

the bonding wire (47) to connect the second wiring portion (46) on the step portion (43c) with the first wiring portion (44) is protected with a resin material; and

the resin material is filled into the through hole (43b) so as not to protrude from the upper surface (43′

) of the seal member (43).

8. A functional element package according to claim 1, wherein

the seal member (43) is made of glass.

9. A functional element package according to claim 1, wherein

the seal member (43) is made of a silicon material.

10. A functional element package according to claim 1, wherein

the airtightly sealed space (43a) is depressurized.

11. A functional element package according to claim 1, wherein

the airtightly sealed space (43a) is filled with inert gas.

12. A functional element package according to claim 1, wherein

the silicon substrate (41a) on which the functional element is formed is bonded with the seal member (43) via an intermediate adhesive layer.

13. A functional element package according to claim 1, wherein

the silicon substrate (41a) on which the functional element is formed is directly bonded with the seal member (43).

16. A fabrication method for a functional element package, comprising the steps of:

fabricating a bonded wafer (114) having a large number of functional element packages (43z″

) thereon by bonding a wafer (111) on which a large number of seal members (43z) according to claim 1 are formed and a wafer (112) on which a large number of microstructures including a functional element are formed; and

cutting the bonded wafer along contours (43y) of the functional element packages (43z″

).

14. A fabrication method for a functional element comprising:

a silicon substrate (41a) on which a functional element is formed, the functional element having one of a mobile portion (42) and a sensor;

a seal member (43) being bonded with the silicon substrate (41a) to airtightly seal the functional element and form an airtightly sealed space (43a) therein, and including a step portion (43c) in its height direction;

a first wiring portion (44) being connected with the functional element and extending from the airtightly sealed space (43a) to an outside thereof;

a second wiring portion (46) being different from the first wiring portion (44) and extending from the step portion (43c) to an upper surface (43′

) of the seal member (43); and

a bump (48) on the second wiring portion (46) on the upper surface (43′

) of the seal member (43), wherein the first wiring portion (44) extending in the outside is bent towards the airtightly sealed space (43a) and connected via a photoconductive member with the second wiring portion (46) on the step portion (43c), the method comprising the step of forming an inclined peripheral wall of the seal member (43) from the upper surface (43′

) to the step portion (43c) by anisotropic wet etching.

15. A fabrication method for a functional element package according to claim 14, further comprising the step of:

concurrently forming the airtightly sealed space (43a) and the step portion (43c) by silicon anisotropic etching.