MEMS Active Structure with Insulating Trench for Electrical Isolation

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Solution Overview

Problem

The challenge in manufacturing micro-electromechanical (MEMS) or micro-opto-electromechanical (MOEMS) components lies in creating active structures with mechanically rigid but electrically isolated parts, where the active structure is only minimally connected to other components to ensure mobility, making electrical insulation between these parts difficult.

Innovation Solution

A method involving the creation of a layered composite with a structural layer that includes a conductive region and an insulating trench, followed by the connection of another composite with a depression, allowing the structural layer to be thinned to the depth of the trench, thereby creating physically rigid and electrically isolated regions within the active structure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the active structure is minimally connected to other elements to ensure mobility, then the mobility of the active structure is improved, but the electrical insulation between separate parts becomes difficult to achieve

Engineering Contradiction:
Improvemobility of active structureVSAvoidelectrical insulation between parts
Core Design Contradiction:
Ease of operationVSEase of manufacture

Solution Approach 1:

The active structure is divided into separate parts (first and second parts) that are mechanically rigidly connected but electrically isolated from each other. This segmentation allows each part to maintain mechanical integrity while achieving electrical insulation through the insulating material filling the trench between them.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

An insulating material is introduced as an intermediary substance filling the trench between the first and second parts of the active structure. This intermediary material provides complete electrical insulation while allowing the parts to remain mechanically connected, thus resolving the contradiction between mobility and electrical insulation.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If a trench is filled with insulating material to achieve electrical insulation, then electrical insulation between parts is improved, but the structural complexity increases

Engineering Contradiction:
Improveelectrical insulation between partsVSAvoidstructural complexity of active structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The trench filling process is merged with the formation of the active structure itself. The insulating material is deposited directly into the trench that defines the boundary between the first and second parts, combining the insulation function with the structural definition, thereby reducing overall complexity.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The active structure employs a composite configuration where conductive regions are separated by an insulating material filled trench. This composite approach allows electrical insulation to be integrated into the structural design, achieving reliable electrical isolation without proportionally increasing complexity.

Inventive Principle:
Principle #40Composite materials

3Reliability

If the first layered composite is connected to the second layered composite, then the hermetic sealing is improved, but the thickness of the first layered composite must be reduced which complicates the process

Engineering Contradiction:
Improvehermetic sealing of active areaVSAvoidprocess complexity of thickness reduction
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The first layered composite is prepared with a thickness greater than the trench depth before connection to the second layered composite. This preliminary thicker state allows for easy hermetic sealing through bonding, and the subsequent thickness reduction to trench depth is performed after connection, simplifying the overall process sequence.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The process utilizes the thickness dimension of the first layered composite as a temporary feature to facilitate hermetic sealing, then reduces it to the required depth for electrical insulation. This dimensional manipulation allows the hermetic sealing to be achieved in a simpler manner before finalizing the electrical insulation configuration.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Data Source

PatentEP3110745B1Method for producing a component
Publication Date: 2017.12.20 NORTHROP GRUMMAN LITEF GMBH
  • EP3110745B1 patent drawingFigure 1~3
  • EP3110745B1 patent drawingFigure 4~6
  • EP3110745B1 patent drawingFigure 7~9

AI summary

In a method for producing a component, a first layer composite is first produced, comprising a structured layer and a trench filled with an insulating material. The structured layer is electrically conductive at least in a first region. The trench filled with an insulating material extends outwards from a first surface of the structured layer and is arranged in the first region of the structured layer. The first surface of the structured layer faces a first surface of the first layer composite. The method additionally has the step of producing a second layer composite, which has a first depression in a first surface of the second layer composite, and the step of connecting the first layer composite to the second layer composite. The first surface of the first layer composite adjoins the first surface of the second layer composite at least in some regions, said filled trench being arranged within the lateral position of the first depression. After the first layer composite has been connected to the second layer composite, the thickness of the first layer composite from a second surface of the first layer composite to the depth of the filled trench is reduced. The second surface of the first layer composite lies opposite the first surface of the first layer composite. The method further has the step of producing an active structure in the structured layer, said active structure comprising two second regions which are arranged in the first region of the structured layer and which are mechanically connected to each other in a rigid manner but are electrically insulated from each other by means of the filled trench.