WAFER LEVEL PACKAGE STRUCTURE, AND SENSOR DEVICE OBTAINED FROM THE SAME PACKAGE STRUCTURE
First Claim
1. A wafer level package structure comprising:
- a semiconductor wafer having a plurality of sensor units, each of which comprises a frame having an open, a movable portion held in said opening to be movable relative to said frame, and a detecting portion configured to output an electric signal according to a positional displacement of said movable portion;
a first package wafer bonded to one of opposite surfaces of said semiconductor wafer; and
a second package wafer bonded to the other surface of said semiconductor wafer;
wherein said frame of each of said sensor units has a first surface-activated region formed on a surface facing the first package wafer over an entire circumference thereof so as to surround said movable portion, and a second surface-activated region formed on a surface facing the second package wafer over an entire circumference thereof so as to surround said movable portion,the bonding between said semiconductor wafer and the first package wafer is a solid-phase direct bonding without diffusion between said first surface-activated region and a surface-activated region formed on the first package wafer, andthe bonding between said semiconductor wafer and the second package wafer is a solid-phase direct bonding without diffusion between said second surface-activated region and a surface-activated region formed on the second package wafer.
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Accused Products
Abstract
A wafer level package structure with a plurality of compact sensors such as acceleration sensors and gyro sensors is provided. This package structure is composed of a semiconductor wafer with plural sensor units, and a pair of package wafers bonded to both surfaces of the semiconductor wafer. Each of the sensor units has a frame having an opening, a movable portion held in the opening to be movable relative to the frame, and a detecting portion for outputting an electric signal according to a positional displacement of the movable portion. Since the semiconductor wafer is bonded to each of the package wafers by a solid-phase direct bonding without diffusion between a surface-activated region formed on the frame and a surface-activated region formed on the package wafer, it is possible to prevent that variations in sensor characteristics occur due to residual stress at the bonding interface.
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Citations
13 Claims
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1. A wafer level package structure comprising:
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a semiconductor wafer having a plurality of sensor units, each of which comprises a frame having an open, a movable portion held in said opening to be movable relative to said frame, and a detecting portion configured to output an electric signal according to a positional displacement of said movable portion; a first package wafer bonded to one of opposite surfaces of said semiconductor wafer; and a second package wafer bonded to the other surface of said semiconductor wafer; wherein said frame of each of said sensor units has a first surface-activated region formed on a surface facing the first package wafer over an entire circumference thereof so as to surround said movable portion, and a second surface-activated region formed on a surface facing the second package wafer over an entire circumference thereof so as to surround said movable portion, the bonding between said semiconductor wafer and the first package wafer is a solid-phase direct bonding without diffusion between said first surface-activated region and a surface-activated region formed on the first package wafer, and the bonding between said semiconductor wafer and the second package wafer is a solid-phase direct bonding without diffusion between said second surface-activated region and a surface-activated region formed on the second package wafer. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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Specification