How to Combine Pressure and Motion Sensors on One Tiny Chip

This patent describes a method for building a single microchip that contains both a pressure sensor and a motion sensor, making devices smaller and more efficient.

What it covers

This device integrates two different types of tiny sensors, a first sensor (like a pressure sensor) and a second sensor (like an inertial sensor), onto a single chip. It uses a first substrate structure with a cavity and a second substrate structure where the sensors are built. The first sensor sits over the cavity, while the second sensor is positioned next to it, laterally spaced apart (Claim 1). A cap then encloses both sensors, often creating separate, isolated chambers for each (Claim 8). A clever part of the manufacturing is that key parts of both sensors, such as the pressure sensor's reference element and the inertial sensor's movable element, can be made at the same time from the same wafer material (Claim 4). For example, a smartphone could use this to measure both atmospheric pressure and how it's moving or tilting.

What it doesn't cover

• —Does not cover a device where the first and second sensors are not laterally spaced apart on the second substrate structure.
• —Does not cover a device where the first sensor is not aligned with a cavity in the first substrate structure.
• —Does not cover a device where the cap does not physically isolate the first sensor's chamber from the second sensor's chamber.
• —Does not cover a device where the reference element of the pressure sensor and the movable element of the inertial sensor are not formed concurrently in the wafer substrate.
• —Does not cover a device where the first sensor is not a pressure sensor or the second sensor is not an inertial sensor.

The clever bit

The innovation lies in the specific fabrication process that allows critical components of different sensor types, like a pressure sensor's reference element and an inertial sensor's movable element, to be formed concurrently within the same wafer substrate. This shared manufacturing step simplifies production and improves alignment.

Why it matters

Combining multiple sensors onto one chip, known as a multi-stimulus sensing device, is crucial for making electronics smaller, lighter, and more power-efficient. This integration reduces the number of separate components needed, which can lower manufacturing costs and simplify device design. This approach is fundamental for compact devices that need to understand both their environment (like air pressure) and their movement (like acceleration or tilt).

Real-world examples

• 1.Smartphones (for altitude, motion tracking, and gaming)
• 2.Wearable fitness trackers (for activity monitoring and elevation changes)
• 3.Drones (for flight stability and altitude control)
• 4.Automotive sensors (for airbag deployment and electronic stability control)