Microbattery Feedthrough Compression Seal for Hermetic Reliability

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Solution Overview

Problem

Existing electrical devices, particularly storage devices like batteries and capacitors, face issues with large dimensions, inadequate sealing, and the use of plastic materials for insulation, leading to poor mechanical stability, temperature resistance, and unreliable seals, especially in accident scenarios.

Innovation Solution

A compact electrical device with a feedthrough design using a metal housing part and a glass or glass ceramic material, where the housing part's coefficient of expansion is greater than the glass material's, creating a compression seal through a flexible flange and pre-stress, ensuring hermetic sealing and improved insulation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional sealing methods are used in metal housings, then manufacturing is simpler, but hermetic sealing reliability deteriorates under thermal stress and vibration

Engineering Contradiction:

Improvehermetic sealing reliabilityVSAvoidfeedthrough structure complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies thermal expansion by designing the metal housing with a higher coefficient of thermal expansion than the glass or glass-ceramic insulating material. During temperature cycles, the metal housing expands and contracts more than the glass material, creating compressive pre-stress on the seal interface that maintains hermetic sealing reliability under thermal stress and vibration conditions.

Inventive Principle:

Principle #37Thermal expansion

Solution Approach 2:

The patent implements preliminary action by applying pre-stress to the seal interface through the differential thermal expansion mechanism before operational conditions are encountered. This pre-compression ensures that the seal remains hermetic even when subjected to subsequent thermal cycles and mechanical vibrations during device operation.

Inventive Principle:

Principle #10Preliminary action

2Quantity of substance

If larger housing dimensions are used, then internal volume and capacity increase, but compactness and portability deteriorate

Engineering Contradiction:

Improveinternal volume for electrolyteVSAvoidoverall device volume

Core Design Contradiction:

Quantity of substanceVSVolume of moving object

Solution Approach 1:

The patent employs thin-walled metal housing construction with optimized wall thickness to maximize internal volume while maintaining structural integrity. The feedthrough design integrates seamlessly with the housing wall, eliminating the need for bulky sealing structures and enabling compact overall dimensions while preserving sufficient internal volume for electrolyte and electrodes.

Inventive Principle:

Principle #30Flexible shells and thin films

3Reliability

If glass or glass-ceramic insulating material is used in the feedthrough, then electrical insulation improves, but mechanical stability under stress deteriorates

Engineering Contradiction:

Improveelectrical insulation performanceVSAvoidmechanical strength under vibration

Core Design Contradiction:

ReliabilityVSStrength

Solution Approach 1:

The patent creates a composite structure by integrating the glass or glass-ceramic insulating material with the metal housing through a compression seal mechanism. The differential thermal expansion between the metal housing and glass material generates compressive pre-stress that mechanically stabilizes the brittle glass component, preventing crack propagation and maintaining mechanical integrity under vibration and shock conditions while preserving electrical insulation properties.

Inventive Principle:

Principle #40Composite materials

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The solution provides a compact, hermetically sealed device with reduced leakage rates, enhanced mechanical stability, and increased assembly space, suitable for microbatteries used in applications like active RFID devices and medical devices.

Implementation Method 1

the housing part has a third coefficient of expansion α3, wherein the third coefficient of expansion α3 is always greater than the second coefficient of expansion α2

Methodology Applied

Scientific EffectThermal expansion: Thermal Expansion

Implementation Method 2

a flexible flange to compensate for thermal stresses

Methodology Applied

Scientific EffectElastic deformation: Elasticity

Data Source

PatentUS12609385B2Electrical device, in particular microbattery, and method for the production

Publication Date: 2026.04.21 SCHOTT AG

AI summary

An electrical device includes: a housing part made of a metal and including a feedthrough therethrough, an opening of the feedthrough, a first region, and a second region, the opening receiving a conductive material or a conductor in a glass material or a glass-ceramic material, wherein: (i) the conductive material has a first coefficient of expansion α1, the glass material or the glass-ceramic material has a second coefficient of expansion α2, and the housing part has a third coefficient of expansion α3, the third coefficient of expansion α3 being always greater than the second coefficient of expansion α2; or (ii) the first region including a width W that is substantially perpendicular to the axis of the at least one opening, the width W of the first region being always greater than a thickness D2 and a thickness DE of the second region; or (iii) a combination of (i) and (ii).