Method of assembling micromechanical sensors

• US 5,273,939 A
• Filed: 01/30/1992
• Issued: 12/28/1993
• Est. Priority Date: 03/09/1991
• Status: Expired due to Fees

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Jaeckel, Klaus, Baumann, Helmut, Becker, Rolf, Weiblen, Kurt, Marek, Jiri, Willmann, Martin, Bantien, Frank
• Primary Examiner(s): Hearn, Brian E.
• Assistant Examiner(s): Picardat, Kevin M.
• Application Number:
  US07/828,106
• Time in Patent Office: 698 Days
• Field of Search: 437/209, 437/133, 437/195, 437/64, 437/65, 156/656, 156/657
• US Class Current: 438/48
• CPC Class Codes: B81B 7/0048 between the MEMS die and the substrate
• CPC Class Codes: G01L 19/147 Details about the mounting of the sensor to support or covering means
• CPC Class Codes: G01P 15/0802 Details
• CPC Class Codes: G01P 2015/0828 the mass being of the paddle type being suspended at one of its longitudinal ends
• 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 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

Abstract

A method is proposed for assembling micromechanical sensors, in particular Hall sensors, or pressure or acceleration sensors, in which at least one silicon sensor element is applied to a substrate. The at least one silicon sensor element is joined to the substrate via at least one assembly pedestal, the cap faces of which are kept small compared with the surface of the silicon sensor element, so that a gap exists between the substrate and the silicon sensor element except for the region of the at least one assembly pedestal.

Claims

1. A method for assembling micromechanical sensors, particularly Hall sensors, pressure or acceleration sensors, in which at least one silicon sensor element is applied to a substrate,

characterized in that

the at least one silicon sensor element (10) is bonded to the substrate (20) via at least one assembly pedestal (11, 12, 13), the bearing faces of which are small compared with the surface area of the silicon sensor element (10), so that a gap (50) exists between the substrate (20) and the silicon sensor element (10), except in the region of the at least one assembly pedestal (11, 12, 13), thereby minimizing temperature-induced tensions between the sensor element (10) and the substrate (20).

2. The method of claim 1,

characterized in that

the at least one assembly pedestal (11, 12, 13) is structured, by isotropic or anisotropic etching, out of the surface, to be joined to the substrate (20), of the silicon sensor element (10).

3. The method of claim 1,

characterized in that

the at least one assembly pedestal (21, 22) is structured out of the surface, to be bonded to the silicon sensor element (10), of the substrate (20).

4. The method of claim 1,

characterized in that

the substrate (20) is a silicon wafer, and the bond between the silicon sensor element (10) and the substrate (20) is produced by direct silicon-to-silicon bonding.

5. The method of claim 1,

characterized in that

the substrate (20) is a glass body, and the bond between the silicon sensor element (10) and the substrate (20) is made by anodic bonding.

6. The method of claim 1,

characterized in that

the bond between the silicon sensor element (10) and the substrate (20) is made by adhesive bonding or soldering.

7. The method of claim 1,

characterized in that

the substrate (20) is a silicon wafer, and that a glass film (43) is applied, preferably by vapor deposition or sputtering, to the surface, to be joined to the substrate (20), of the silicon sensor element (10), or to the surface, to be joined to the silicon sensor element (10), of the substrate (20).

8. The method of claim 7,

characterized in that

the glass film (43) is structured in such a manner that the glass film (43) is maintained, at least in the region of the bearing faces of the assembly pedestals.

9. The method of claim 1,

characterized in that

a glass wafer is applied to the surface, to be bonded to the substrate (20), of the silicon sensor element (10) or to the surface, to be bonded to the silicon sensor element (10), of the substrate (20), and that the glass wafer is preferably removed again by back-polishing and etching, except for at least one region that forms the at least one assembly pedestal (41, 42).

10. The method of claim 7,

characterized in that

the bond between the silicon sensor element (10) and the substrate (20) is made by anodic bonding.

11. The method of claim 1,

characterized in that

a plurality of silicon sensor elements (10) are applied to one substrate (20), and not until after the bonding of the silicon sensor elements (10) to the substrate (20) are they separated, preferably by sawing out the silicon sensor elements (10) and sawing through the substrate (20).