Input Capacitance Measurement Circuit Using Segmented Capacitors

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Solution Overview

Problem

Existing input capacitance measurement circuits for semiconductor devices face challenges in accurately measuring input capacitance while maintaining a small device size, as increasing breakdown voltage of bypass capacitors leads to increased dimensions and measurement errors.

Innovation Solution

The proposed input capacitance measurement circuit employs a transformer with primary and secondary wires, along with capacitors, to accurately measure input capacitance by ensuring the breakdown voltage of capacitors is higher than the power supply voltage, allowing for smaller capacitor dimensions and improved measurement accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the breakdown voltage of the bypass capacitor is increased to measure higher voltages, then the measurement capability is improved, but the dimensions of the capacitor increase

Engineering Contradiction:

Improvemeasurement capabilityVSAvoidcapacitor dimensions

Core Design Contradiction:

ReliabilityVSVolume of moving object

Solution Approach 1:

The bypass capacitor is divided into two separate capacitors (first capacitor and second capacitor) that are connected in series. This segmentation allows each capacitor to handle a portion of the total voltage, enabling the measurement of higher voltages without requiring each individual capacitor to have high breakdown voltage, thus maintaining compact dimensions.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent transitions from a single-capacitor architecture to a two-capacitor series architecture, adding a dimensional aspect to the voltage handling capability. By distributing the voltage stress across multiple components in series, the system achieves high voltage measurement capability without proportionally increasing the physical size of individual components.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Volume of moving object

If the capacitance of the bypass capacitor is decreased to reduce dimensions, then the capacitor size is reduced, but the measurement error of the input capacitance increases

Engineering Contradiction:

Improvecapacitor dimensionsVSAvoidinput capacitance measurement accuracy

Core Design Contradiction:

Volume of moving objectVSMeasurement precision

Solution Approach 1:

By dividing the bypass capacitor into two smaller capacitors connected in series, each capacitor can have smaller individual capacitance values while their combined effect maintains the necessary measurement accuracy. The series connection allows the system to achieve the desired voltage handling capability without sacrificing measurement precision.

Inventive Principle:

Principle #1Segmentation

3Volume of moving object

If the dimensions of the measurement device are reduced, then the device portability is improved, but the breakdown voltage capability may be compromised

Engineering Contradiction:

Improvemeasurement device dimensionsVSAvoidbreakdown voltage capability

Core Design Contradiction:

Volume of moving objectVSReliability

Solution Approach 1:

The measurement device uses segmented capacitor architecture where two smaller capacitors replace one large high-voltage capacitor. This allows the overall device dimensions to be reduced while maintaining the necessary breakdown voltage capability through the series connection of the smaller capacitors.

Inventive Principle:

Principle #1Segmentation

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 enhances measurement accuracy of input capacitance while minimizing the increase in dimensions of the capacitors, effectively addressing the limitations of conventional methods.

Implementation Method 1

a transformer having a primary wire and a secondary wire; The primary wire of the transformer has a first end provided so as to be connectable to an anode of the semiconductor device

Methodology Applied

Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentUS11774476B2Input capacitance measurement circuit and method of manufacturing semiconductor device

Publication Date: 2023.10.03 MITSUBISHI ELECTRIC CORP

AI summary

An input capacitance measurement circuit includes a transformer, a first capacitor, a second capacitor, and a third capacitor. A primary wire of the transformer has a first end provided so as to be connectable to an anode of the semiconductor device. The primary wire of the transformer has a second end connected to a first end of the first capacitor. A secondary wire of the transformer has a first end provided so as to be connectable to a cathode of the semiconductor device. The secondary wire of the transformer has a second end connected to a first end of the second capacitor. The third capacitor has a first end provided so as to be connectable to the cathode of the semiconductor device. A second end of the first capacitor, a second end of the second capacitor, and a second end of the third capacitor are electrically connected to each other.