Single-Wafer Magnetic Sensor Chip for Azimuth Detection

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Solution Overview

Problem

Existing magnetic direction detectors using different wafers for each axis sensor result in varying magnetic properties, leading to detection sensitivity errors and increased size, failing to accurately detect geomagnetism and meet downsizing requirements.

Innovation Solution

A sensor chip with a single wafer design, allowing the same sensor chip to be mounted horizontally or at an angle on a circuit substrate, using the same electrodes for both configurations, eliminating the need for a sub-circuit substrate and simplifying manufacturing, thereby ensuring uniform sensor properties and reducing device size.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If different wafers are used for each axis sensor, then each sensor can be optimized for its specific axis, but the magnetic properties vary among sensors leading to detection sensitivity errors

Engineering Contradiction:
Improvedetection sensitivityVSAvoiddetection accuracy
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent merges multiple sensor chips (X-axis, Y-axis, and Z-axis magnetic sensors) onto a single circuit substrate. This integration ensures that all sensors share the same manufacturing environment and magnetic property characteristics, eliminating detection sensitivity errors caused by variations between different wafers while maintaining optimized performance for each axis.

Inventive Principle:
Principle #5Merging (Combining)

2Adaptability or versatility

If separate sub-circuit substrates are used for mounting sensors, then sensor arrangement flexibility is improved, but the device size increases and manufacturing complexity increases

Engineering Contradiction:
Improvesensor arrangement flexibilityVSAvoiddevice size
Core Design Contradiction:
Adaptability or versatilityVSVolume of moving object

Solution Approach 1:

The patent combines multiple sensor chips and the control semiconductor onto a single circuit substrate, eliminating the need for separate sub-circuit substrates. This integration reduces the overall device size and thickness while maintaining the flexibility to arrange sensors in optimal positions for detecting geomagnetism in three axes.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The circuit substrate serves multiple functions: it acts as the mounting platform for all sensor chips (X, Y, and Z-axis sensors), provides electrical connections through electrodes and lead wires, and integrates the control semiconductor. This multi-functional design eliminates the need for separate sub-circuit substrates while maintaining sensor arrangement flexibility.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Ease of manufacture

If different electrode configurations are used for cross sensors, then proper electrical connection is achieved, but the structure becomes complex and manufacturing requires multiple sensor chip types

Engineering Contradiction:
Improveelectrode connectionVSAvoidsensor chip variety
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The patent employs a universal electrode configuration where the same electrode arrangement on each sensor chip serves multiple purposes depending on the sensor's mounting orientation. The electrodes can connect sensors mounted horizontally or vertically to the circuit substrate, eliminating the need for different electrode configurations for cross sensors and reducing manufacturing complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent makes the sensor chip mounting orientation dynamic rather than fixed. The same sensor chip design can be mounted in different orientations (horizontal or vertical) on the circuit substrate, with the electrode configuration adapting to serve proper electrical connections in either orientation. This flexibility reduces the need for multiple specialized sensor chip types.

Inventive Principle:
Principle #15Dynamics

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 approach enhances detection accuracy, reliability, and reduces manufacturing costs by using identical sensor chips for all axes, preventing detection errors and minimizing device thickness while maintaining high performance.

Implementation Method 1

a sensor chip with at least one sensing axis... an X-axis magnetic sensor for detecting an X-axis geomagnetism, a Y-axis magnetic sensor for detecting a Y-axis geomagnetism, and a Z-axis magnetic sensor for detecting a Z-axis geomagnetism

Methodology Applied
Scientific EffectMagnetic field detection: Magnetic Field

Data Source

PatentEP2116858B1Sensor chip, detecting device, and method for manufacturing detecting device
Publication Date: 2013.01.02 ALPS ALPINE CO LTD
  • EP2116858B1 patent drawingFigure 1
  • EP2116858B1 patent drawingFigure 2~3
  • EP2116858B1 patent drawingFigure 4(a)~5

AI summary

[Object] To provide a highly reliable detection device for accurately detecting the azimuth while reducing the size of the detection device. [Means for Solving the Problem] The detection device includes an X-axis magnetic sensor 7a, a Y-axis magnetic sensor 7b, and a Z-axis magnetic sensor 7c each having a sensing axis 8 for detecting a geomagnetic azimuth and a sensor controlling semiconductor 9. The magnetic sensors 7 are selected from those fabricated from the same wafer, each having the same structure, and directly mounted on the circuit substrate 3 by directing the respective sensing axes 8 of the magnetic sensors 7 at different predetermined angles. Electrodes 15a, 15b and 15c of the magnetic sensors 7 for conducting the sensor controlling semiconductor 9 are located in a parallel row at one side of the sensing surface.