Power Semiconductor Temperature Sensor Isolation

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Solution Overview

Problem

Conventional power semiconductor devices with integrated temperature sensors face the risk of PNPN latch-up, which can damage the temperature detecting diode and driving circuit due to parasitic thyristor formation, leading to potential device failure from overheating.

Innovation Solution

The integration of a temperature sensing diode within the power semiconductor chip, isolated by a P-type semiconductor isolation region, eliminates PNPN junctions and parasitic thyristor formation through vertical and lateral isolation techniques, including trench isolation and a silicon-on-insulator structure, ensuring reliable temperature monitoring without latch-up.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a temperature detecting diode is formed on the power semiconductor device chip, then temperature monitoring capability is improved, but the risk of PNPN latch-up increases due to parasitic thyristor formation

Engineering Contradiction:

Improvetemperature monitoring capabilityVSAvoidlatch-up risk

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

An n-type isolation region is introduced as an intermediary structure between the temperature detecting diode and the power semiconductor device. This isolation region acts as a barrier that prevents parasitic current flow and blocks the formation of PNPN latch-up paths, thereby eliminating the harmful latch-up effect while preserving temperature monitoring functionality

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The device structure is segmented into distinct functional regions: the temperature sensing region, the isolation region, and the power device region. This segmentation physically separates the temperature detecting diode from the power semiconductor structures, preventing harmful interactions while maintaining independent functionality of each region

Inventive Principle:

Principle #1Segmentation

2Device complexity

If the temperature sensor and driving circuit are integrated on the same chip, then device complexity is reduced, but manufacturing precision requirements increase due to isolation structure needs

Engineering Contradiction:

Improveintegration levelVSAvoidisolation structure precision

Core Design Contradiction:

Device complexityVSManufacturing precision

Solution Approach 1:

The temperature sensor and driving circuit are merged onto the same chip substrate, creating an integrated temperature monitoring system. This integration reduces the number of discrete components and interconnections, simplifying the overall device structure while the isolation region ensures proper functional separation

Inventive Principle:

Principle #5Merging (Combining)

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 solution prevents latch-up effects, enhances the reliability of the temperature sensing device, and reduces parasitic current flow, ensuring the integrity of both the temperature sensor and the power semiconductor device during operation.

Implementation Method 1

The forward voltage is proportionate to the temperature of the power semiconductor device

Methodology Applied

Scientific EffectTemperature dependency of forward voltage:

Data Source

PatentUS11508723B2Power semiconductor device with a temperature sensor

Publication Date: 2022.11.22 DYNEX SEMICONDUCTOR

AI summary

We describe herein a high voltage semiconductor device comprising a power semiconductor device portion (100) and a temperature sensing device portion (185). The temperature sensing device portion comprises: an anode region (140), a cathode region (150), a body region (160) in which the anode region and the cathode region are formed. The temperature sensing device portion also comprises a semiconductor isolation region (165) in which the body region is formed, the semiconductor isolation region having an opposite conductivity type to the body region, the semiconductor isolation region being formed between the power semiconductor device portion and the temperature sensing device portion.