Strain Gauge Resin Substrate Creep Reduction

Solution Overview

Problem

Strain gauges formed with resin substrates often experience creep, which poses a significant challenge in maintaining accuracy and reliability.

Innovation Solution

The strain gauge incorporates a resin substrate with a resistor formed from a film containing Cr, CrN, and Cr2N on one side, and an inorganic insulating layer on the other side, positioned to overlap the resistor region, thereby reducing creep.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a resin substrate is used for the strain gauge, then ease of manufacture and flexibility are improved, but creep occurs leading to reduced measurement precision and reliability

Engineering Contradiction:

Improveease of manufactureVSAvoidmeasurement precision

Core Design Contradiction:

Ease of manufactureVSMeasurement precision

Solution Approach 1:

The patent applies composite materials by combining the resin substrate with an inorganic insulating layer having low creep characteristics. This composite structure allows the strain gauge to maintain the manufacturing advantages of resin substrates while compensating for their creep-related precision issues through the stabilizing effect of the inorganic layer.

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The patent changes the physical and chemical parameters of the substrate system by selecting specific inorganic insulating materials with particular creep resistance properties. By adjusting the material composition and thermal expansion coefficients of the inorganic layer, the overall creep behavior of the strain gauge is optimized while maintaining resin substrate benefits.

Inventive Principle:

Principle #35Parameter changes

2Ease of manufacture

If a resin substrate is used for the strain gauge, then flexibility and ease of manufacture are improved, but reliability deteriorates due to creep

Engineering Contradiction:

Improveease of manufactureVSAvoidreliability

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The patent applies composite materials by combining the resin substrate with an inorganic insulating layer having low creep characteristics. This composite structure allows the strain gauge to maintain the manufacturing advantages of resin substrates while compensating for their creep-related precision issues through the stabilizing effect of the inorganic layer.

Inventive Principle:

Principle #40Composite materials

3Measurement precision

If the inorganic insulating layer is formed to overlap the resistor region, then measurement precision is improved by reducing creep, but device complexity increases

Engineering Contradiction:

Improvemeasurement precisionVSAvoiddevice complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent applies local quality by forming the inorganic insulating layer specifically at positions overlapping the resistor region rather than uniformly across the entire substrate. This localized approach provides creep compensation precisely where it is needed for measurement accuracy while minimizing the additional complexity and material usage compared to a full-coverage layer.

Inventive Principle:

Principle #3Local quality

Data Source

PatentUS20250102380A1Strain gauge

Publication Date: 2025.03.27 MINEBEAMITSUMI INC

AI summary

A strain gauge according to the present disclosure includes: a resin substrate; a resistor formed of a film containing Cr, CrN, and Cr2N on one side of the substrate; and an inorganic insulating layer formed on another side of the substrate, and, in this strain gauge, the inorganic insulating layer is formed at least at a position overlapping a region where the resistor is formed in plan view.