Micromechanical Component With Insulating Bridge Cap

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Solution Overview

Problem

The production of micromechanical components, such as sensors and actuators, requires a large number of complex and cost-intensive process steps for forming conductor tracks and conductor track levels below the functional layer, which can be simplified by using an encapsulation layer with trenches and connecting webs that serve as both mechanical fixations and conductor tracks.

Innovation Solution

The method involves applying an encapsulation layer with trenches and connecting webs that are mechanically fixed to the functional layer, allowing the encapsulation layer elements to act as conductor tracks and eliminating the need for elaborate process steps in forming conductor tracks below the functional layer, with the connecting webs providing variable insulation and mechanical support.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If conductor tracks and conductor track levels are formed below the functional layer using traditional processes, then electrical connectivity is achieved, but the number of process steps increases and production cost increases

Engineering Contradiction:
Improveproduction process simplicityVSAvoidnumber of process steps
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The encapsulation layer is designed to perform multiple functions simultaneously: it provides mechanical protection, creates electrical isolation through trenches, and serves as conductor tracks through its remaining connecting webs. This multi-functionality eliminates the need for separate conductor track formation processes below the functional layer, directly reducing the number of process steps while maintaining electrical connectivity.

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

Solution Approach 2:

Instead of forming conductor tracks in the traditional bottom-up approach (substrate level, then building up layers), the invention inverts the approach by using the top encapsulation layer to provide both protection and electrical connectivity. The conductor tracks are formed in the encapsulation layer itself rather than in underlying layers, fundamentally changing the sequence and nature of manufacturing steps.

Inventive Principle:
Principle #13The other way round (Inversion)

2Reliability

If the encapsulation layer is completely enclosed with trenches for electrical isolation, then electrical isolation is improved, but mechanical stability may be compromised

Engineering Contradiction:
Improveelectrical isolationVSAvoidmechanical stability
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The encapsulation layer is segmented into isolated elements by trenches, achieving electrical isolation. However, the segmentation is controlled such that connecting webs remain intact to provide mechanical stability. This selective segmentation allows the structure to be electrically isolated while maintaining mechanical integrity through the remaining connecting portions.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the encapsulation layer have different properties: the trench regions provide electrical isolation, while the connecting web regions provide mechanical stability. This local differentiation of quality allows the same component to simultaneously achieve both electrical isolation and mechanical strength in different locations.

Inventive Principle:
Principle #3Local quality

3Quantity of substance

If connecting webs are made thinner to reduce insulation requirements, then material usage decreases, but mechanical load-bearing capacity is reduced

Engineering Contradiction:
Improvematerial usageVSAvoidmechanical load-bearing capacity
Core Design Contradiction:
Quantity of substanceVSStrength

Solution Approach 1:

The connecting webs are formed as composite structures combining the encapsulation layer material with additional insulating material filled in the trenches. This composite approach allows the connecting webs to maintain mechanical strength while the trench regions provide sufficient electrical isolation, optimizing both material usage and structural integrity.

Inventive Principle:
Principle #40Composite materials

Data Source

PatentEP2164800B1Micromechanical component and method for producing a micromechanical component having a thin layer cap
Publication Date: 2017.05.03 ROBERT BOSCH GMBH
  • EP2164800B1 patent drawingFigure 1a~1e
  • EP2164800B1 patent drawingFigure 1f~1h
  • EP2164800B1 patent drawingFigure 1i~1k

AI summary

The invention relates to a micromechanical component having a substrate, a micromechanical functional layer located over the substrate, and a capping layer located over the functional layer, and to a method for producing the micromechanical component, the capping layer comprising at least one trench, the trench being bridged by at least one electrically insulating connecting bridge.