Multilayer NTC Component for Automotive Inrush Current Limiting
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Solution Overview
Problem
Conventional NTC thermistor components are prone to 'hotspots' and insufficient inrush current limitation, which can lead to voltage drops that compromise safety and efficiency in applications like automotive start-stop systems, and they lack optimal design for specific applications.
Innovation Solution
A multilayer electronic component with internal electrodes and functional layers made of ceramic materials, arranged to provide direct electrical connections between external contacts, reducing hotspot formation and enhancing inrush current limitation by distributing current effectively through the internal electrodes and functional layers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional NTC thermistor components are used, then the component structure is simple, but inrush current limitation is insufficient and voltage drops occur
Solution Approach 1:
The NTC component is divided into multiple functional layers (first functional layer, second functional layer, third functional layer) with distinct roles. The first functional layer provides inrush current limitation, the second functional layer provides thermal conduction path, and the third functional layer provides additional current limitation. This segmentation allows each layer to be optimized for its specific function, improving overall reliability while maintaining manageable complexity through modular design
Solution Approach 2:
The patent uses composite material structure where different functional layers are made of materials with specific properties. The first functional layer uses NTC material for inrush current limitation, the second functional layer uses thermally conductive material for heat dissipation, and the third functional layer uses NTC material for additional current limitation. This composite approach enables the component to simultaneously achieve multiple functions that a single material could not provide
2Reliability
If conventional NTC thermistor components are used, then the manufacturing process is simple, but hotspot formation occurs
Solution Approach 1:
The component is segmented into multiple thin functional layers instead of a single thick layer. This segmentation creates multiple thermal conduction paths through the second functional layer, distributing heat flow and preventing concentration of thermal energy in a single location, thereby preventing hotspot formation while maintaining manufacturing feasibility through layer-by-layer fabrication
Solution Approach 2:
Different regions of the component have different local properties optimized for their specific functions. The second functional layer is designed with high thermal conductivity in the region where heat dissipation is critical, while the first and third functional layers maintain NTC properties for current limitation. This local optimization prevents hotspots without requiring complete redesign of the entire manufacturing process
3Reliability
If the inrush current is limited too much, then the voltage drop is excessive, but if limited too little, then safety-relevant applications cannot be supplied with intended voltage
Solution Approach 1:
The current limitation function is segmented across three functional layers instead of being concentrated in a single layer. This distribution allows the voltage drop to be distributed across multiple layers, preventing excessive voltage drop in any single layer while collectively achieving sufficient inrush current limitation. The series connection of the three layers provides cumulative current limitation with distributed voltage drop, maintaining voltage supply stability for safety-relevant applications
Solution Approach 2:
The patent optimizes the resistance values and thickness parameters of the three functional layers to achieve the desired balance. By carefully selecting the resistance parameters of each layer and their thickness, the component achieves sufficient inrush current limitation while maintaining adequate voltage levels for critical applications during the start-up phase
4Reliability
If a single-layer NTC component is used, then the device complexity is low, but the heating time does not match the electrical start-up time
Solution Approach 1:
The single-layer structure is segmented into three functional layers with different thermal and electrical properties. The second functional layer provides a dedicated thermal conduction path that controls the heating time constant, while the first and third functional layers provide inrush current limitation. This segmentation enables independent optimization of heating time and current limitation characteristics, allowing the heating time to match the electrical start-up time of the load device
Solution Approach 2:
The multilayer structure provides multiple functions within a single component: the first functional layer provides inrush current limitation, the second functional layer provides thermal conduction and heating time control, and the third functional layer provides additional current limitation. This multi-functionality allows the component to simultaneously control both the electrical and thermal characteristics to match the load start-up profile
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 multilayer design effectively limits inrush currents, prevents hotspot formation, and maintains sufficient voltage for critical systems, enhancing safety and energy efficiency in applications like automotive start-stop systems by reducing voltage drops and increasing current-carrying capacity.
Implementation Method 1
the functional layers are thermally conductive layers
Implementation Method 2
NTC component with a negative temperature coefficient
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
The invention relates to an electronic component (10) comprising a plurality of functional layers (3) arranged on top of each other to form a stack, comprising first inner electrodes (1), and comprising second inner electrodes (2). Each of the first and second inner electrodes (2) is arranged between two adjacent functional layers (3), wherein the first inner electrodes (1) are connected to a first outer contact (11) of the electronic component (10), and the second inner electrodes (2) are connected to a second outer contact (12) of the electronic component (10) in an electrically conductive manner. The functional layers (3) are selected such that both in a basic state and in a hot state of the electronic component (10), that is, at a temperature that is higher than that of the electronic component (10) in the basic state, the first and the second outer contact (11, 12) are connected to one another in an electrically conductive manner by way of the functional layers (3), and wherein the electronic component (10) is an NTC component.