TVS Diode With Integrated MIM Capacitor for Harmonic Reduction

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Solution Overview

Problem

Transient voltage suppression (TVS) diodes generate unwanted harmonics due to their non-linear capacitance, which causes interference and distortions in RF or power lines, particularly in applications near radio frequency signal paths or power lines.

Innovation Solution

A semiconductor device with a metal-insulator-metal (MIM) capacitor integrated in parallel with the TVS diode to provide a linear capacitance value, masking the non-linear capacitance of the TVS diode and reducing harmonic generation, by forming a semiconductor die with trenches and using conductive and insulating layers to create a stable capacitance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a TVS diode is used to suppress transient voltage spikes, then protection against voltage transients is improved, but harmonic generation increases causing interference and distortions

Engineering Contradiction:
Improveprotection against voltage transientsVSAvoidharmonic generation
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent combines a TVS diode with a capacitor to form an integrated device. The capacitor is connected in parallel with the TVS diode, merging two separate components into a single packaged unit. This combination allows the device to provide both transient voltage suppression and harmonic filtering functions simultaneously, reducing the need for separate components while addressing both protection and interference reduction requirements.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The capacitor acts as an intermediary element that mediates between the nonlinear TVS diode and the external circuit. By placing the capacitor in parallel with the TVS diode, it provides a linearizing effect on the overall capacitance, reducing the nonlinear characteristics that generate harmonics. The capacitor essentially masks or compensates for the nonlinear behavior of the TVS diode, allowing both components to coexist without the full negative effects of the TVS diode's nonlinearity.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If the capacitance of the TVS diode is increased to improve protection, then the suppression capability is improved, but the non-linear capacitance effect increases causing more harmonics

Engineering Contradiction:
Improvesuppression capabilityVSAvoidharmonic interference
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent merges a capacitor with a TVS diode into an integrated device. The capacitor is connected in parallel with the TVS diode, combining their functions. This allows the overall device to have enhanced suppression capability from the TVS diode while the capacitor provides linearizing capacitance that reduces harmonic generation, effectively decoupling the relationship between suppression capability and harmonic interference.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent changes the overall capacitance characteristics of the device by adding a capacitor in parallel with the TVS diode. This modifies the voltage-capacitance relationship of the combined device, making it more linear than the TVS diode alone. The capacitor's linear capacitance dominates at higher voltages, reducing the nonlinear effects that generate harmonics while maintaining the suppression capability provided by the TVS diode's breakdown characteristics.

Inventive Principle:
Principle #35Parameter changes

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 integration of a MIM capacitor with the TVS diode results in a semiconductor device with improved harmonic characteristics, reducing harmonic interference and protecting electronic devices from transient voltage spikes while maintaining a stable capacitance.

Implementation Method 1

A semiconductor device with a metal-insulator-metal (MIM) capacitor integrated in parallel with the TVS diode to provide a linear capacitance value, masking the non-linear capacitance of the TVS diode and reducing harmonic generation

Methodology Applied
Scientific EffectCapacitance: Capacitance

Implementation Method 2

TVS diodes are solid-state, silicon avalanche devices that are constructed with one or more p-n junctions

Methodology Applied
Scientific EffectAvalanche breakdown: Avalanche Breakdown

Implementation Method 3

The TVS diode shunts transient voltage spikes away from the load through the TVS diode to protect the load

Methodology Applied
Scientific EffectDiode conduction: Diode

Data Source

PatentEP3306661B1Transient voltage suppression diodes with reduced harmonics, and associated method of making
Publication Date: 2022.06.01 SEMTECH CORP
  • EP3306661B1 patent drawingFigure 1a~1c
  • EP3306661B1 patent drawingFigure 1d~1e
  • EP3306661B1 patent drawingFigure 2a

AI summary

A semiconductor device includes a semiconductor die. A transient voltage suppression (TVS) structure is formed in the semiconductor die. A capacitor is formed over the semiconductor die. In one embodiment, the capacitor is formed by depositing a first conductive layer over the semiconductor die, depositing an insulating layer over the first conductive layer, and depositing a second conductive layer over the semiconductor die. In another embodiment, the capacitor is formed by forming a trench in the semiconductor die, depositing an insulating material in the trench, and depositing a conductive material in the trench.