# Combining Sealed and Exposed Sensors on One Microchip > This patent describes a microchip design that integrates multiple tiny sensors on the same side, where one sensor is exposed to the outside world through a backside hole while others remain protected by a sealed cap. - **Patent:** US 8387464 - **Original title:** Laterally integrated MEMS sensor device with multi-stimulus sensing - **Owner:** Freescale Semiconductor - **Granted:** 2013 - **Status:** Active - **Times cited:** 21 - **Field:** consumer_electronics, telecommunications, semiconductors, software ## What it does This patent describes a microelectromechanical systems (MEMS) sensor device that integrates multiple sensors on a single chip. It includes a substrate with a 'first side' and an opposing 'second side' (claim 1). A 'first sensor' and a 'second sensor' are both placed on the 'first side' of this substrate, at different locations (claim 1). The 'second sensor' contains a 'sense element' (claim 1), which is the part that detects physical changes. A key feature is a 'cavity' that extends through the substrate from the 'second side' (the back) to expose this 'sense element' of the second sensor to the external environment (claim 1). This allows the sense element, for example a diaphragm in a pressure sensor, to move in response to an external stimulus like pressure (claim 2). Both the first and second sensors are then enclosed together within a 'hermetically sealed chamber' formed by a cap coupled to the 'first side' of the substrate (claim 1). This setup allows for sensors with different environmental exposure needs to be manufactured on the same chip, such as an inertial sensor (first sensor) and a pressure sensor (second sensor) (claim 3). ## What it does NOT cover - Does not cover a device where the first and second sensors are placed on opposite sides of the substrate, as both are required to be on the 'first side' (claim 1). - Does not cover a device where the cavity for the second sensor's sense element does not extend completely through the substrate from the 'second side' (claim 1). - Does not cover a device where both the first and second sensors are directly exposed to the external environment via through-substrate cavities. - Does not cover a device that lacks a 'hermetically sealed chamber' enclosing both the first and second sensors (claim 1). - Does not cover a device where the sensors are not 'laterally spaced apart' on the substrate, meaning they are at distinct locations (claim 1). ## The clever bit The clever part is integrating sensors with fundamentally different environmental requirements on the same side of a microchip. It allows one sensor (like a pressure sensor) to be exposed to the outside through a precisely etched hole from the back of the chip, while other sensors (like accelerometers) remain protected within a single, shared hermetically sealed chamber, simplifying manufacturing and packaging. ## Real-world examples 1. Integrated pressure and inertial sensors in smartphones 2. Multi-sensor modules in smartwatches and fitness trackers 3. Environmental monitoring sensors in Internet of Things (IoT) devices 4. Combined altimeter and motion sensors in drones ## Why it matters This patent addresses a common challenge in microchip manufacturing: how to combine different types of sensors, some needing to be sealed from the outside world (like accelerometers) and others needing direct exposure (like pressure sensors), onto a single, compact chip. By providing a method to expose only specific parts of one sensor through a backside cavity while keeping others sealed under a common cap, it enables the creation of smaller, more efficient multi-sensor modules. This integration is vital for reducing the size, cost, and power consumption of devices that require multiple types of environmental sensing. ## Frequently asked questions ### What does Combining Sealed and Exposed Sensors on One Microchip cover? This patent describes a microchip design that integrates multiple tiny sensors on the same side, where one sensor is exposed to the outside world through a backside hole while others remain protected by a sealed cap. ### Who owns patent US 8387464? Freescale Semiconductor owns this patent, granted in 2013. ### When does this patent expire? This patent is expected to expire on November 30, 2029, when the invention enters the public domain. ### What is patent US 8387464 cited by? This patent has been cited by 21 later patents that build on its ideas. ### What problem does this patent solve? This patent addresses a common challenge in microchip manufacturing: how to combine different types of sensors, some needing to be sealed from the outside world (like accelerometers) and others needing direct exposure (like pressure sensors), onto a single, compact chip. By providing a method to expose only specific parts of one sensor through a backside cavity while keeping others sealed under a common cap, it enables the creation of smaller, more efficient multi-sensor modules. This integration is vital for reducing the size, cost, and power consumption of devices that require multiple… ### What does this patent NOT cover? Does not cover a device where the first and second sensors are placed on opposite sides of the substrate, as both are required to be on the 'first side' (claim 1). **Full plain-English explainer:** https://patentbrief.org/patent/us/8387464/laterally-integrated-mems-sensor-device-with-multi-stimulus-sensing **Original patent:** https://patents.google.com/patent/US8387464 --- _Source: PatentBrief — https://patentbrief.org. Patent facts are from public records; the plain-English explanation is PatentBrief's._ ## Related patents Semantically similar inventions in the PatentBrief corpus: - [How a Tiny Sensor Uses an Extra Weight to Detect Motion](https://patentbrief.org/patent/us/20110120221/mems-sensor-method-of-manufacturing-thereof-and-electronic-apparatus) — This patent describes a miniature sensor that detects movement or force by measuring changes in electrical signals between tiny plates, featuring a clever extra weight to make it more sensitive. - [How to Stack Computer Chips on a Wafer for Smaller Devices](https://patentbrief.org/patent/us/7824959/wafer-level-stack-structure-for-system-in-package-and-method-thereof) — This patent describes a method for stacking two full wafers of computer chips, where the chips on each wafer are roughly the same overall size but have different active areas, to create a compact system-in-package. - [Attaching Flexible Circuits with Light Sensors to a Chip](https://patentbrief.org/patent/us/9055681/method-for-attaching-a-flexible-structure-to-a-device-and-a-device-having-a-flex) — This patent describes a method and device for attaching a bendable circuit, which includes light-sensing or light-emitting components, onto a main chip, allowing light to pass through a hole in the chip to reach the flexible part. - [How Chips Are Stacked and Wired in Tiny Phone Parts](https://patentbrief.org/patent/us/8310051/package-on-package-with-fan-out-wlcsp) — MediaTek's 2012 patent describes a way to stack different types of computer chips, like a processor and memory, very closely together in a single package using special wiring that spreads out connections, saving space in devices like smartphones. - [How TSMC Makes Advanced Silicon-Based Light Sensors](https://patentbrief.org/patent/us/12310123/raptor-1) — A manufacturing process for high-performance light sensors that use alternating doped regions within a silicon-on-insulator structure to improve detection efficiency.