Ultra-small GSR Sensor Integration on ASIC
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Solution Overview
Problem
Existing GSR sensors face challenges in downsizing while maintaining detection sensitivity, particularly in thickness reduction, due to separate manufacturing and joining of sensor elements and ASICs.
Innovation Solution
Integrally forming a GSR element on an ASIC by using a substrate film with a groove for a magnetic wire and detection coil, with an insulating protective film serving as a substrate, allowing for through-hole type jointing and reducing sensor thickness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of stationary object
If separate manufacturing and joining of GSR elements and ASICs is used, then manufacturing flexibility is maintained, but sensor thickness cannot be reduced below a certain limit
Solution Approach 1:
The patent merges the GSR element and ASIC into a single integrated structure where the GSR element is formed directly on the ASIC substrate. This eliminates the need for separate manufacturing and joining processes, enabling ultra-thin sensor design (0.05 mm or less) while reducing structural complexity by removing interface components and joining mechanisms.
Solution Approach 2:
The patent transitions from a three-dimensional assembly of separate components to a planar two-dimensional integration approach. The GSR element is formed in the same plane as the ASIC surface, allowing thickness reduction to 0.05 mm or less while maintaining functional connectivity through lateral electrode connections rather than vertical joining.
2Volume of moving object
If GSR sensor size is reduced for in-vivo motion device mounting, then device miniaturization is achieved, but detection sensitivity decreases
Solution Approach 1:
The patent changes the geometric parameters of the coil structure, specifically using a coil pitch of 10 μm or smaller and optimizing the number of turns and winding density. This allows the sensor to maintain high detection sensitivity (0.1 mG to 1 mG) even when the overall sensor volume is reduced to ultra-small dimensions suitable for in-vivo motion devices.
Solution Approach 2:
The patent employs composite material structures combining magnetic wires with specific permeability characteristics and coil materials that maximize magnetic field coupling efficiency. This enables enhanced sensitivity in a compact volume by optimizing the magnetic properties and spatial arrangement of the composite sensor structure.
3Ease of manufacture
If conventional GSR element formation processes are used directly on ASIC surface, then manufacturing simplicity is maintained, but insulating protective film damage and ASIC circuit function reduction occur
Solution Approach 1:
The patent performs preliminary formation of the insulating protective film with appropriate thickness and material properties before depositing the GSR element structure. This preliminary action creates a robust protective layer that withstands subsequent manufacturing processes such as plasma treatment and chemical etching, preventing damage to underlying ASIC circuits while maintaining manufacturing simplicity.
Solution Approach 2:
The patent introduces an intermediate buffer layer or cushioning structure between the ASIC surface and the GSR element that absorbs mechanical and chemical stress during manufacturing. This beforehand cushioning protects the fragile insulating protective film and underlying circuits from damage during plasma processing, etching, and other fabrication steps.
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 enables the creation of ultra-small and high-sensitive GSR sensors with reduced thickness, achieving sizes of 0.07 mm to 0.4 mm in width and 0.25 mm to 1 mm in length, while maintaining sensitivity for magnetic field detection.
Implementation Method 1
the GSR sensor refers to a high-sensitivity micro magnetic sensor based on the GHz Spin Rotation effect
Data Source
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AI summary
The thickness of a substrate film formed on an upper surface of an insulating protective film of an ASIC is 1 µm to 20 µm, a groove of a depth of 1 µm to 10 µm is attached onto the substrate film, an element is formed such that a part or all of a coil is embedded along a groove surface, electrodes of the element and the ASIC are electrically connected via an electrode joint part of a through hole type passing through the insulating protective film and the substrate film, and the thickness of the element part from the ASIC surface is 20 µm or smaller.