Ceramic NTC Sensor Element for Direct Power Module Thermal Coupling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing temperature sensors in power modules suffer from unreliable connections and indirect thermal coupling, limiting accurate temperature measurement due to the use of conventional NTC thermistors with inadequate electrode materials and mounting methods.
Innovation Solution
A sensor element with a ceramic carrier and structured electrodes, including multi-layered Cu, Ni, Pd, and Au layers, allows direct integration onto a conductor path of a power module, enabling reliable electrical and thermal connection through soldering, silver sintering, and wire bonding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If NTC thermistors are mounted on separate conductive paths, then manufacturing is simplified, but temperature measurement precision is limited due to indirect thermal connection
Solution Approach 1:
The patent merges the NTC thermistor mounting location with the IC power supply path by placing the thermistor directly on the IC's power electrode. This integration maintains manufacturing simplicity while achieving direct thermal coupling, thereby improving temperature measurement precision without complicating the manufacturing process.
2Device complexity
If conventional NTC thermistors with separate mounting are used, then device complexity is reduced, but thermal coupling efficiency is insufficient for accurate measurement
Solution Approach 1:
The patent combines the NTC thermistor directly onto the IC's power electrode, merging the sensing element with the thermal path. This integration maintains relatively simple device structure while establishing reliable direct thermal coupling, eliminating the need for complex separate mounting arrangements and improving thermal coupling reliability.
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 precise and reliable temperature monitoring by directly coupling the sensor to the IC, ensuring robustness against thermomechanical stresses and reducing manufacturing costs.
Implementation Method 1
NTC thermistors are the most widely used because of their low manufacturing costs. Another advantage of NTC thermistors over thermocouples and metallic resistive elements, such as Pt elements, is their distinct negative resistance-temperature characteristic.
Implementation Method 2
The carrier has a material with a high thermal conductivity. Preferably, the carrier has a ceramic material.
Implementation Method 3
thick-film electrodes mainly made of silver or gold pastes are applied for this purpose via a screen-printing process with subsequent firing
Implementation Method 4
The sensor element is designed to be integrated in an electrically insulating manner directly onto a conductor path of a power module
Implementation Method 5
Sintering under pressure at low temperatures with finely dispersed silver pastes
Data Source
AI summary
In an embodiment a sensor element includes a carrier having an electrically insulating material, a top side and a bottom side, an NTC thermistor arranged on the top side of the carrier and at least two first electrodes configured for electrically contacting the sensor element, wherein the first electrodes are arranged on the top side of the carrier, wherein the sensor element is configured to measure a temperature, and wherein the sensor element is configured for direct integration in an electrically insulating manner.