3D Capacitor Electrode for Implantable Semiconductor Devices

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Solution Overview

Problem

Implantable semiconductor devices face challenges in integrating bulky capacitors for electrical isolation due to their large capacitance requirements, which can lead to risks of continuous voltages from the external environment affecting the electrode in contact with biological tissue, and existing solutions using metal lines on printed circuit boards are not satisfactory.

Innovation Solution

The device features a capacitor electrode with a first surface facing and in contact with the electrode configured to be in contact with biological tissue, minimizing the distance between them and eliminating the need for metal lines, using a three-dimensional capacitor structure with pillars, trenches, or holes, and stacked capacitors connected in series or parallel to enhance capacitance and security.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a DC block capacitor is used to ensure electrical isolation and prevent continuous voltages, then safety and electrical isolation are improved, but the capacitor becomes bulky and difficult to integrate

Engineering Contradiction:
Improveelectrical isolationVSAvoidcapacitor size
Core Design Contradiction:
ReliabilityVSVolume of moving object

Solution Approach 1:

The patent transitions from planar capacitors to three-dimensional capacitors with vertical stacking architecture. Multiple capacitor layers are stacked vertically with shared electrode structures, effectively utilizing the third dimension (height) to increase capacitance density without increasing the planar footprint. This dimensional transition resolves the contradiction by providing sufficient capacitance for electrical isolation while maintaining a compact form factor suitable for implantable devices.

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

Solution Approach 2:

The patent implements nested capacitor structures where intermediate electrodes serve dual purposes: they act as electrodes for one capacitor layer while simultaneously serving as electrodes for adjacent capacitor layers. This nesting approach allows multiple capacitors to be integrated within a reduced volume by sharing common structural elements, thereby achieving the required capacitance for electrical isolation without proportionally increasing device volume.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Ease of manufacture

If capacitors are placed on a printed circuit board with metal lines, then integration is achieved, but risks of continuous voltages from external environment affecting the electrode increase

Engineering Contradiction:
ImproveintegrationVSAvoidexternal voltage interference
Core Design Contradiction:
Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The patent merges the capacitor structure directly with the electrode structure by forming capacitors in immediate proximity to or in direct contact with the biological tissue electrode. This integration eliminates the need for separate metal line connections on a printed circuit board, thereby maintaining ease of manufacture while simultaneously reducing the exposure area to external electromagnetic interference and continuous voltage risks.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent extracts the harmful intermediate metal line connections from the signal path between the electrode and capacitor. By forming direct contact or minimal-distance coupling between the electrode and capacitor, the design removes the vulnerable metal line traces that would otherwise extend across the printed circuit board and expose the system to external voltage interference, while still achieving functional integration.

Inventive Principle:
Principle #2Taking out (Extraction)

3Object-affected harmful factors

If the distance between electrode and capacitor is minimized, then protection from external voltage is improved, but manufacturing precision requirements increase

Engineering Contradiction:
Improveexternal voltage interferenceVSAvoidalignment precision
Core Design Contradiction:
Object-affected harmful factorsVSManufacturing precision

Solution Approach 1:

The patent employs preliminary action by forming the capacitor structure first, then using the capacitor's electrode as a template or reference for subsequent electrode deposition. This sequential fabrication approach ensures automatic alignment and minimizes the distance between electrode and capacitor without requiring high-precision alignment steps, as the positioning is determined by the pre-formed capacitor structure rather than requiring precise registration between separately fabricated components.

Inventive Principle:
Principle #10Preliminary action

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

This configuration reduces the risk of external voltage interference, achieves miniaturization for precise neuronal stimulation, and provides improved security and capacitance density, making it suitable for deep brain, cardiac, and spinal cord stimulation with reduced side effects.

Implementation Method 1

the capacitor is required to have a large capacitance value. The capacitor has to be able to ensure electrical isolation

Methodology Applied
Scientific EffectCapacitance: Capacitance

Data Source

PatentEP3632504B1Implementable semiconductor device, comprising an electrode and capacitor, and corresponding manufacturing method
Publication Date: 2022.11.30 MURATA MFG CO LTD
  • EP3632504B1 patent drawingFigure 1~2
  • EP3632504B1 patent drawingFigure 3
  • EP3632504B1 patent drawingFigure 4~5

AI summary

The invention concerns an implementable semiconductor device, comprising an electrode (209) configured to be in contact with biological tissue and at least one capacitor (200), wherein the capacitor comprises a capacitor electrode (201) having a first surface facing and in contact with the electrode configured to be in contact with biological tissue.