Magnetic Sensor Resin Seal with Directional Shielding
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Solution Overview
Problem
Magnetic sensor packages face difficulties in adjusting magnetic field intensity in directions differing from the detected magnetic field, leading to limited application scope and increased size and manufacturing costs due to the need for separate magnetic shields and yokes.
Innovation Solution
A magnetic sensor device with a magnetic sensor chip and sealing body composed of resin with magnetic particles, where the thickness of certain sealing parts allows for magnetic shield or yoke functions in specific directions, eliminating the need for separate components and enabling compact size and cost-effective manufacturing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a magnetic shield is provided to reduce interfering magnetic fields, then noise resistance is improved, but adjusting the magnetic field intensity of the detected magnetic field becomes difficult
Solution Approach 1:
The sealing body is divided into multiple sealing parts with different thicknesses. The first sealing part has a thickness smaller than the particle diameter of magnetic particles, creating a region without magnetic particles for magnetic field detection. The second sealing part has a thickness larger than the particle diameter, containing magnetic particles for shield functions. This segmentation allows different regions to serve different magnetic field control purposes simultaneously.
Solution Approach 2:
Different regions of the sealing body are given different magnetic properties through varying thicknesses. The first sealing part (thinner) provides a non-magnetic region for detecting the target magnetic field, while the second sealing part (thicker) provides a magnetic region for shielding against interfering fields. This local differentiation of magnetic properties enables both detection and shielding functions within a single integrated structure.
2Measurement precision
If a magnetic yoke is provided to focus the detected magnetic field, then detection precision is improved, but adjusting the magnetic field intensity in other directions becomes difficult
Solution Approach 1:
The sealing body is segmented into multiple sealing parts with different thicknesses. The first sealing part (thinner) creates a region without magnetic particles that allows magnetic field lines to concentrate and pass through, providing a magnetic yoke effect for focusing the detected magnetic field. The second sealing part (thicker) contains magnetic particles for shielding. This segmentation enables both yoke and shield functions in different directions within one structure.
Solution Approach 2:
Different local regions of the sealing body have different magnetic characteristics. The thinner first sealing part provides a path for magnetic flux concentration (yoke function), while the thicker second sealing part provides magnetic shielding. This local quality differentiation enables directional control of magnetic fields with different properties.
3Adaptability or versatility
If separate magnetic shields and yokes are provided to control magnetic fields in different directions, then magnetic field control capability is improved, but device size and manufacturing cost increase
Solution Approach 1:
The patent combines the functions of magnetic shield and magnetic yoke into a single sealing body. By varying the thickness of different sealing parts, the structure simultaneously provides magnetic shielding in some directions and magnetic flux concentration (yoke effect) in other directions. This merging eliminates the need for separate magnetic shield and yoke components, reducing device complexity and manufacturing cost.
Solution Approach 2:
The sealing body is designed to perform multiple functions: it seals the magnetic sensor chip, provides magnetic shielding against interfering fields, and acts as a magnetic yoke to focus the detected magnetic field. By making the sealing body multi-functional through differential thickness design, the patent eliminates the need for separate dedicated components for each function.
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
Enables adjustment of magnetic field intensity in multiple directions, achieving a compact design and reducing manufacturing costs while maintaining effective magnetic field manipulation within usable ranges.
Implementation Method 1
a magnetic sensor device according to an embodiment of the present invention provides a magnetic sensor chip (2) having a substantially rectangular shape in a plan view and including a magnetic sensor element, and a sealing body (6) integrally sealing the magnetic sensor chip (2). The sealing body (6) is composed of a resin material containing magnetic particles (7) and includes a first sealing part (61) positioned on the first side surface, a second sealing part (62) positioned on the second side surface, a third sealing part (63) positioned on the third side surface, and a fourth sealing part (64) positioned on the fourth side surface. The thicknesses of the first sealing part (61) and the second sealing part (62) are smaller than the particle diameter of the magnetic particles (7), and the thickness of at least the third sealing part (63) is larger than the particle diameter of the magnetic particles (7). The magnetic particles (7) exist in at least the third sealing part (63) and substantially do not exist in the first sealing part (61) and the second sealing part (62).
Implementation Method 2
the thicknesses of the first sealing part (61) and the second sealing part (62) are smaller than the particle diameter of the magnetic particles (7), and the thickness of at least the third sealing part (63) is larger than the particle diameter of the magnetic particles (7). The magnetic particles (7) exist in at least the third sealing part (63) and substantially do not exist in the first sealing part (61) and the second sealing part (62).
Implementation Method 3
As the magnetic sensor element included in the magnetic sensor chip, magnetoresistive effect elements (AMR elements, GMR elements, TMR elements and the like), the resistance of which changes in accordance with the external magnetic field
Implementation Method 4
Hall elements that use the so-called Hall effect
Data Source
AI summary
A magnetic sensor device comprises a magnetic sensor chip that has a substantially rectangular shape and that contains a magnetic sensor element; and a sealing body, which is composed of a resin material containing magnetic particles and that integrally seals the chip. The chip includes a first and second side surfaces which are mutually opposite to each other, and a third and fourth side surfaces which are mutually opposite to each other and orthogonal to the first and second side surfaces. The sealing body contains first to forth sealing parts. The thicknesses of the first and second sealing parts are smaller than the particle diameter of the particles, and the thickness of at least the third sealing part is larger than the particle diameter of the particles. The particles exist in at least the third sealing part and substantially do not exist in the first and second sealing parts.