Split Die-Attach Paddle for 3D Magnetic Field Sensing
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Solution Overview
Problem
Existing planar integrated circuit packages, such as DIP and QIP, are inefficient in sensing magnetic fields in all three dimensions due to their footprint occupying valuable space on the substrate and limited magnetic field sensing capabilities.
Innovation Solution
A single in-line package (SIP) with a split die-attach paddle (DAP) that supports semiconductor die with magnetic field sensing elements, featuring an hourglass-shaped split to reduce magnetic reluctance and eddy currents, allowing enhanced magnetic field sensing in three dimensions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If planar packages (DIP/QIP) are used, then the sensor can sense magnetic fields in two dimensions, but the footprint occupies valuable space on the substrate and sensing in the third dimension is ineffective
Solution Approach 1:
The patent transitions from planar two-dimensional magnetic field sensing to three-dimensional sensing by positioning the magnetic field sensing element vertically above the split DAP. This vertical arrangement enables the sensor to detect magnetic fields in all three spatial dimensions (x, y, and z), resolving the limitation of planar packages that could only sense in two dimensions while maintaining a compact footprint.
2Measurement precision
If a continuous DAP is used, then mechanical support is provided, but magnetic reluctance and eddy currents reduce sensing performance
Solution Approach 1:
The DAP is divided into two separate portions by introducing a split between them. This segmentation eliminates the continuous conductive path that would otherwise generate eddy currents and create magnetic reluctance. The split DAP structure allows magnetic field lines to pass through the sensing region without being obstructed by eddy currents, thereby improving magnetic field sensing accuracy while still providing mechanical support through the lead frame structure.
3Measurement precision
If the split DAP is entirely separated, then magnetic reluctance is reduced, but mechanical stability may be compromised
Solution Approach 1:
The lead frame serves as an intermediary structure that provides mechanical support and stability to the split DAP. While the DAP portions are electrically and magnetically separated to reduce eddy currents and magnetic reluctance, the lead frame maintains their positional stability and structural integrity, ensuring that the mechanical stability requirement is met while achieving improved magnetic field sensing performance.
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
The SIP design enhances magnetic field sensing capabilities in three dimensions by reducing magnetic reluctance and eddy currents, providing mechanical stability and improved performance for magnetic field sensors.
Implementation Method 1
The DAP may be adapted to substantially eliminate a magnetic reluctance between the DAP and the at least one magnetic field sensing element
Implementation Method 2
The split may entirely separate the first portion and the second portion of the DAP... featuring an hourglass-shaped split to reduce magnetic reluctance and eddy currents
Data Source
AI summary
An integrated circuit package includes a lead frame with a split die-attach paddle (DAP) that supports a semiconductor die with one or more magnetic field sensing elements. The split paddle reduces magnetic reluctance for enhancing coupling to the die and reducing eddy currents. The package provides mechanical stability to prevent die tilt, limiting sensing errors and protecting the die from stress from downstream mechanical forces during test and assembly pick processes. The mechanical stability is provided by one or more leads, strip tie-bars and/or band bars.