MEMS Capping Structure with Independent Pressure Cavities

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing MEMS devices integrated on a single substrate face challenges in optimizing the performance of accelerometer and gyroscope components due to differing operating conditions, as they require different gas pressures for optimal performance, which is difficult to achieve with conventional packaging methods.

Innovation Solution

The integration of multiple MEMS devices on a single substrate with a capping structure that includes separate cavities for each device, allowing independent control of gas pressures within these cavities, with a vent mechanism to adjust the pressure of one cavity relative to another, and a lid to seal the cavities hermetically.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If multiple MEMS devices are integrated on a single substrate with conventional packaging, then device integration is achieved, but optimal performance of each device cannot be achieved due to uniform pressure conditions

Engineering Contradiction:

Improveperformance optimizationVSAvoidpackaging structure

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The packaging structure is segmented into multiple separate cavities, each housing a specific MEMS device. The capping structure includes a first cavity for a first MEMS device and a second cavity for a second MEMS device, allowing each device to experience different gas pressures independently. This segmentation enables each MEMS device to operate under its optimal pressure conditions while being integrated on a single substrate.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the packaging structure are assigned different gas pressures to match the specific performance requirements of each MEMS device type. The first cavity is filled with gas at a first pressure optimized for the first MEMS device, while the second cavity is filled with gas at a second pressure optimized for the second MEMS device. This local quality approach ensures that each device operates in its optimal environment.

Inventive Principle:

Principle #3Local quality

2Adaptability or versatility

If separate cavities with independent pressure control are implemented, then performance optimization is achieved, but manufacturing complexity increases

Engineering Contradiction:

Improveindependent pressure controlVSAvoidcapping structure fabrication

Core Design Contradiction:

Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The capping structure is pre-formed with multiple separate cavities and pressure control mechanisms integrated into the structure before final assembly. The recesses and vents are incorporated into the capping structure during fabrication, enabling subsequent independent pressure adjustment without requiring complex post-processing or assembly steps. This preliminary action simplifies the overall manufacturing process despite the increased functional complexity.

Inventive Principle:

Principle #10Preliminary action

3Measurement precision

If pressure optimization for each device is achieved, then functional accuracy is enhanced, but device complexity increases

Engineering Contradiction:

Improvefunctional accuracyVSAvoidcavity and vent structure

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The pressure control mechanism is nested within the capping structure itself. Recesses are formed in the capping structure to define the cavities, and vents are integrated into the same structure. This nesting approach allows multiple functional elements (cavities, recesses, vents) to be combined in a compact arrangement, reducing overall device complexity while maintaining independent pressure control capability for each MEMS device.

Inventive Principle:

Principle #7Nested doll (Nesting)

Data Source

PatentUS9856139B2Microelectromechanical systems (MEMS) devices at different pressures

Publication Date: 2018.01.02 TAIWAN SEMICONDUCTOR MANUFACTURING CO LTD

AI summary

The present disclosure relates to a method of forming a micro-electro mechanical system (MEMs) structure. In some embodiments, the method may be performed by providing a device substrate having a first MEMS device and a second MEMS device, and by providing a capping structure having a first cavity and a second cavity. The capping structure is bonded to the device substrate, such that the first cavity is arranged over the first MEMS device and the second cavity is arranged over the second MEMS device. A first pressure is established within the first cavity and the second cavity. A vent is selectively etched within the capping structure to change the first pressure within the second cavity to a second pressure, which is different from the first pressure.