Panasonic Electric Works Co., Ltd.

Takashi Saijo

Toru Baba

Hisakazu Miyajima

Yoshiyuki Takegawa

Kazushi Kataoka

Yuji Suzuki

Takafumi Okudo

Kouji Gotou

A wafer level package structure, in which a plurality of compact sensor devices with small variations in sensor characteristics are formed, and a method of producing the same are provided. This package structure has a semiconductor wafer having plural sensor units, and a package wafer bonded to the semiconductor wafer. The semiconductor wafer has a first metal layer formed with respect to each of the sensor units. The package wafer has a bonding metal layer at a position facing the first metal layer. Since a bonding portion between the semiconductor wafer and the package wafer is formed at room temperature by a direct bonding between activated surfaces of the first metal layer and the bonding metal layer, it is possible to prevent that variations in sensor characteristics occur due to residual stress at the bonding portion.

Wafer level package structure and production method therefor

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.

Wafer level package structure, and sensor device obtained from the same package structure

A sensor device having small variations in sensor characteristics and improved resistance to electrical noise is provided. This sensor device has a sensor unit, which is provided with 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, and a package substrate made of a semiconductor material, and bonded to a surface of the sensor unit. The package substrate has an electrical insulating film on a surface facing the sensor unit. The package substrate is bonded to the sensor unit by forming a direct bonding between an activated surface of the electrical insulating film and an activated surface of the sensor unit at room temperature.

Sensor device and production method therefor

A compact sensor device having stable sensor characteristics and the production method are provided. The sensor device is formed with a sensor substrate and a pair of package substrates bonded to both surface of the sensor substrate. The sensor substrate has a frame with 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. Surface-activated regions are formed on the frame of the sensor substrate and the package substrates by use of an atomic beam, an ion beam or a plasma of an inert gas. By forming a direct bonding between the surface-activated regions of the sensor substrate and each of the package substrates at room temperature, it is possible to avoid inconvenience resulting from residual stress at the bonding portion.

Growing community of inventors

Kawanishi, Japan

Takashi Saijo