MEMS Cover Wafer Integration for Compact Sensor Packaging

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing microelectromechanical components face challenges in integrating electrical functions due to the large size caused by cover wafers and inefficient use of surface area for bonding areas, particularly in small sensor solutions and frequency stabilization applications.

Innovation Solution

A method for manufacturing microelectromechanical components where a cover part with lead-in structures is used to integrate electronic circuit parts, allowing for direct bonding and redistribution layers to facilitate conductive connections, reducing the need for external encapsulation and optimizing surface area usage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional encapsulation methods with cover wafers are used for microelectromechanical components, then mechanical protection is provided, but the component size becomes large and surface area for bonding is inefficiently utilized

Engineering Contradiction:
Improvemechanical protectionVSAvoidcomponent size
Core Design Contradiction:
ReliabilityVSVolume of moving object

Solution Approach 1:

The patent merges the cover wafer and the electronic circuit substrate into a single integrated structure. The cover wafer serves dual purposes: providing mechanical protection for the MEMS device and serving as the substrate for mounting electronic circuit components. This integration eliminates the need for separate encapsulation and circuit carrier, significantly reducing overall component size while maintaining protective functionality.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The cover wafer is designed to perform multiple functions simultaneously: it acts as a protective enclosure for the MEMS device, provides a mounting platform for electronic circuits, enables bonding connections through integrated bond pads, and serves as part of the electrical connection system. This multi-functionality reduces the number of separate components needed, optimizing space utilization.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Reliability

If separate encapsulation and circuit integration are performed, then mechanical protection is achieved, but surface area usage for bonding becomes inefficient

Engineering Contradiction:
Improvemechanical protectionVSAvoidbonding surface area
Core Design Contradiction:
ReliabilityVSArea of stationary object

Solution Approach 1:

The bonding interface is integrated into the cover wafer structure itself. Bond pads are directly formed on the cover wafer surface at strategic locations, allowing mechanical bonding of the MEMS device to the electronic circuit substrate without requiring separate bonding areas. This integration maximizes the utilization of the cover wafer surface area for both protection and electrical/mechanical connections.

Inventive Principle:
Principle #5Merging (Combining)

3Volume of moving object

If wafer-level packaging is applied to microelectromechanical components, then size and cost are reduced, but the necessary cover for mechanical protection complicates the encapsulation process

Engineering Contradiction:
Improvecomponent sizeVSAvoidencapsulation complexity
Core Design Contradiction:
Volume of moving objectVSDevice complexity

Solution Approach 1:

The encapsulation structure is merged with the circuit carrier function. The cover wafer is designed to simultaneously provide mechanical protection and serve as the substrate for electronic circuits, eliminating the need for separate encapsulation steps and reducing overall device complexity despite the added requirement of a cover structure.

Inventive Principle:
Principle #5Merging (Combining)

4Adaptability or versatility

If lead-in structures are integrated into the cover part, then connectivity is enhanced, but manufacturing complexity increases

Engineering Contradiction:
ImproveconnectivityVSAvoidmanufacturing complexity
Core Design Contradiction:
Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The lead-in structures are integrated directly into the cover wafer manufacturing process. Conductive traces and bonding pads are formed on the cover wafer using standard semiconductor fabrication techniques during the same process sequence that creates the protective cover structure. This integration enhances connectivity while avoiding additional separate manufacturing steps.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP1951611B1Method for manufacturing a microelectromechanical component, and a microelectromechanical component
Publication Date: 2016.08.17 MURATA ELECTRONICS OY
  • EP1951611B1 patent drawingFigure 1
  • EP1951611B1 patent drawingFigure 2
  • EP1951611B1 patent drawingFigure 3

AI summary

The invention relates to microelectromechanical components, like microelectromechanical gauges used in measuring e.g. acceleration, angular acceleration, angular velocity, or other physical quantities. The microelectromechanical component, according to the invention, comprises, suitably bonded to each other, a microelectromechanical chip part (46), (60) sealed by a cover part (24), (28), (33), (41), (47), (48), and at least one electronic circuit part (63), (78), (83). The aim of the invention is to provide an improved method of manufacturing a microelectromechanical component, and to provide a microelectromechanical component, which is applicable for use particularly in small microelectromechanical sensor solutions.