IGBT Chip Temperature Sensor Shielding Against EMI Crosstalk
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Solution Overview
Problem
Existing IGBT chips face challenges in accurately monitoring temperature due to interference from electromagnetic interference (EMI) and crosstalk between signal transmission paths, which affects the accuracy of temperature sensing when a temperature sensor is integrated directly into the chip.
Innovation Solution
The IGBT chip integrates a temperature sensor within the gate finger structure, accompanied by a conductive shielding structure connected to the emitter pad, which shields transmission signals and prevents crosstalk, ensuring accurate temperature monitoring.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the temperature sensor is directly integrated into the IGBT chip, then the response time constant is small and temperature can be obtained more quickly and accurately, but the distance between the signal circuit and metal lead is short, causing interference to the monitoring signal and reducing temperature sensing accuracy
Solution Approach 1:
The patent introduces a shielding structure as an intermediary element between the temperature sensor's metal lead and the high-frequency signal circuit. This shielding structure, connected to ground, acts as a mediator that blocks electromagnetic interference from the signal circuit from coupling into the temperature sensing signal path, thereby resolving the contradiction between close integration for fast response and distance for EMI reduction
Solution Approach 2:
The shielding structure is designed to preemptively counteract electromagnetic interference before it can affect the temperature sensing signal. By placing the ground-connected shielding layer adjacent to the metal lead in the gate finger structure, the patent creates a preliminary protective barrier that prevents EMI coupling, allowing the temperature sensor to be integrated closely without suffering from signal interference
2Speed
If the temperature sensor is packaged separately with the IGBT chip, then the distance between sensor and chip is short for heat conduction, but the response speed is low and accuracy is reduced
Solution Approach 1:
The patent merges the temperature sensor with the gate finger structure of the IGBT chip, integrating both components into a single unified structure. The temperature sensor is positioned within the gate finger structure and electrically connected to the emitter pad, achieving close thermal coupling for fast response while maintaining electrical isolation through the shielding structure to prevent signal interference
3Loss of time
If the temperature sensor is integrated into the IGBT chip, then response time is improved, but device complexity increases due to additional shielding requirements
Solution Approach 1:
The shielding structure is designed to serve multiple functions simultaneously: it provides electromagnetic interference shielding for the temperature sensor, acts as an electrical connection path to ground, and integrates within the existing gate finger structure layout. This multi-functionality approach reduces the need for separate shielding components, thereby limiting the increase in device complexity while achieving fast temperature response
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 enhances temperature monitoring accuracy by minimizing EMI effects and crosstalk, allowing for precise temperature detection while maintaining miniaturization and reducing production costs.
Implementation Method 1
The conductive shielding structure is at least disposed between the gate finger structure and a part that is of the metal lead and that is located in the gate finger structure, and is insulated from the metal lead and the gate finger structure. The conductive shielding structure is electrically connected to the emitter pad.
Data Source
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AI summary
This application provides an IGBT chip integrating a temperature sensor, and relates to the field of power device technologies, to improve accuracy of temperature monitoring of the IGBT chip. The IGBT chip integrating the temperature sensor includes a cell region, an emitter pad, a gate pad, a gate finger structure, a temperature sensing module, and a conductive shielding structure. The emitter pad is electrically connected to emitters of a plurality of IGBT cells. The gate finger structure is connected between the gate pad and gates of the plurality of IGBT cells. The temperature sensing module includes a temperature sensor, an anode pad, a cathode pad, and a metal lead. The temperature sensor and at least a part of the metal lead are located in the gate finger structure and are insulated from the gate finger structure. The conductive shielding structure is at least disposed between the gate finger structure and a part that is of the metal lead and that is located in the gate finger structure, and is electrically connected to the emitter pad. The IGBT chip integrating the temperature sensor provided in this application is used in an electric vehicle or an elevator.