Multilevel Hall Sensor Package for Void-Free Current Sensing
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Solution Overview
Problem
Hall sensor packages using etched lead frames face issues such as mold voiding, limited design flexibility, large size, and inability to accommodate additional components due to two-dimensional structures and single metal layer wiring, which affect voltage performance and signal routing.
Innovation Solution
A multilevel package substrate with a conductive U-shaped trace and exposed conductive lead, allowing for a semiconductor die with a Hall sensor positioned above the trace, enclosed by a package structure, which includes magnetic material for improved magnetic field sensing and allows for additional components and reduced size.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If etched lead frames are used for Hall sensor packaging, then the package structure is simple to manufacture, but mold voiding occurs near the sensed current conductor which decreases voltage performance
Solution Approach 1:
The patent transitions from a two-dimensional lead frame structure to a three-dimensional multilevel package substrate with conductive traces distributed across multiple levels. This dimensional change allows current paths to be routed through different planes (top level, bottom level, intermediate levels) and connected via vias, eliminating the mold voiding issue that plagues planar lead frame designs while maintaining manufacturing feasibility through established multilevel PCB fabrication processes.
2Ease of manufacture
If lead frame structures are used, then the package can be manufactured with standard processes, but the two-dimensional layout limits design flexibility and increases package size
Solution Approach 1:
The multilevel package substrate utilizes vertical stacking of conductive trace layers to achieve complex current sensing geometries without increasing the planar footprint. Designers can route current paths through multiple levels and use vias to create three-dimensional current loops, providing significant design flexibility for optimizing magnetic field generation while maintaining a compact package footprint and using standard multilevel PCB manufacturing processes.
3Ease of manufacture
If etched lead frames with single metal layer wiring are used, then the manufacturing process is simplified, but signal routing capabilities are limited and I/O count is reduced
Solution Approach 1:
The patent segments the conductive wiring into multiple independent metal layers distributed vertically through the package substrate. Each level can carry different signal paths, allowing multiple current sensing inputs, output signals, and power connections to be routed through different layers and vias. This segmentation enables high I/O count and complex signal routing while maintaining manufacturing simplicity through standardized multilevel PCB fabrication techniques.
4Device complexity
If lead frame-based packages are used, then the package structure is straightforward, but interior terminals are not isolated and additional components cannot be mounted
Solution Approach 1:
The multilevel package substrate uses vertical layering to provide three-dimensional spatial separation of functional elements. Interior terminals on different levels are naturally isolated by the dielectric layers between conductive planes. This vertical arrangement creates discrete mounting locations on multiple surfaces and sides of the package, enabling integration of additional components such as capacitors, inductors, or other sensors without increasing planar complexity, while the modular layer structure maintains straightforward manufacturing.
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 solution ensures void-free molding, reduces device size, enhances design flexibility, and increases signal routing capabilities, ensuring reliable Hall sensor performance and higher I/O count.
Implementation Method 1
The top level of the multilevel package substrate has a conductive U-shaped trace... The semiconductor die has a Hall sensor positioned above the U-shaped trace
Implementation Method 2
Hall sensors are used for current sensing in a variety of applications, such as providing current feedback signals in motor drives... The semiconductor die has a Hall sensor positioned above the U-shaped trace
Data Source
AI summary
An electronic device includes a multilevel package substrate having a top level and a bottom level, the top level including a conductive U-shaped trace, the bottom level including a conductive lead exposed along a side of the electronic device, a semiconductor die attached to the top level of the multilevel package substrate and having a Hall sensor positioned above the U-shaped trace, and a package structure that encloses a portion of the semiconductor die and a portion of the U-shaped trace.