Shunt Resistor Electrode Layout for Low-TCR Current Sensing

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Solution Overview

Problem

Existing shunt resistors face challenges in maintaining stable current detection due to significant temperature fluctuations, which are influenced by the temperature coefficient of resistance (TCR) characteristics.

Innovation Solution

The current detection device incorporates a shunt resistor design with specific slit configurations and voltage detection portions arranged to minimize the temperature coefficient of resistance by positioning voltage detection points closer to the resistive element, reducing potential distribution and temperature influence.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If voltage detection portion is positioned away from resistive element for easier manufacturing, then manufacturing precision is improved, but temperature coefficient of resistance increases reducing measurement accuracy

Engineering Contradiction:

Improveease of manufacturingVSAvoidtemperature coefficient of resistance

Core Design Contradiction:

Manufacturing precisionVSMeasurement precision

Solution Approach 1:

The voltage detection portion is positioned in the thickness direction (z-axis) rather than only in the plane direction, allowing it to be located close to the resistive element's side surface while maintaining ease of manufacturing through the detection area structure

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Reliability

If electrode material with high conductivity is used, then electrical conductivity is improved, but temperature influence on resistance increases

Engineering Contradiction:

Improveelectrical conductivityVSAvoidtemperature influence

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The voltage detection function is extracted from the bulk electrode material and concentrated in a specific detection area with defined slits, separating the high-conductivity requirement from the temperature-sensitive measurement function

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The detection area has different structural characteristics from the rest of the electrode, with slits creating a localized region that minimizes temperature coefficient while maintaining overall electrode conductivity through the contact surface

Inventive Principle:

Principle #3Local quality

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 design enables more accurate and stable current detection by minimizing the temperature coefficient of resistance, thereby improving voltage measurement precision and reducing the impact of electrode material temperature characteristics.

Implementation Method 1

a voltage generated at the both ends of the resistive element is detected by connecting a conductor (e.g., aluminum wire) to the voltage detection portion

Methodology Applied

Scientific EffectElectrical Resistance: Electrical Resistance

Data Source

PatentUS12480975B2Current detection device

Publication Date: 2025.11.25 KOA CORP

AI summary

The present invention relates to a current detection device, in particular a current detection device using a shunt resistor. The current detection device (30) includes a resistive element (5) and a pair of electrodes (6, 7). The electrodes (6, 7) have detection areas (24a, 25a) demarcated by first slits (16, 17), second slits (26, 27), and contact surfaces (6a, 7a) that at least partially contacts the resistive element (5). The electrodes (6, 7) further have voltage detection portions (20, 21) arranged in the detection areas (24a, 25a).