Power Electronics Package Layout With Kelvin Loop Separation
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Solution Overview
Problem
Conventional power discrete packages face issues with coupling between power switching loops and signal loops, leading to reduced switching quality, slower speeds, increased losses, and potential destruction of power semiconductor die due to feedback, and also present layout complexities and transconductance mismatches when paralleling semiconductor die.
Innovation Solution
The package design includes a power substrate with power semiconductor die, a Kelvin connection contact, and conductive traces that simplify the layout by directly coupling the Kelvin connection pad to the Kelvin connection contact, reducing connection lengths and ensuring independence of power and signal loops, thereby minimizing feedback and transconductance mismatches.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the second power switching contact and Kelvin connection contact are coupled together before connecting to power semiconductor die, then the layout is simplified, but coupling between power switching loop and signal loop occurs causing feedback
Solution Approach 1:
The patent segments the connection paths by providing separate conductive traces for the second power switching contact and the Kelvin connection contact on the power substrate. This segmentation prevents the coupling of power and signal loops while maintaining layout simplicity, as each trace independently connects to its respective contact without requiring pre-coupling.
Solution Approach 2:
The power substrate acts as an intermediary element that provides separate conductive pathways for power and signal connections. By using the substrate's conductive traces as intermediaries, the patent achieves both layout simplification and loop independence, avoiding the need to couple contacts together before connection.
2Reliability
If connection length between Kelvin connection contact and power semiconductor die is reduced, then feedback is minimized, but layout flexibility is constrained
Solution Approach 1:
The power substrate serves multiple functions simultaneously: it provides mechanical support, electrical isolation between traces, and dedicated conductive pathways for both power and signal connections. This multi-functionality allows the substrate to accommodate various die placements while maintaining optimal connection lengths for minimizing feedback.
Solution Approach 2:
The patent utilizes the two-dimensional surface of the power substrate to route conductive traces in optimal paths that minimize connection length between the Kelvin connection contact and power semiconductor die. By planning trace routes across the substrate plane, the design achieves short connections without constraining layout flexibility.
3Power
If multiple power semiconductor die are paralleled in a discrete package, then current handling capacity increases, but transconductance mismatches and layout complexity increase
Solution Approach 1:
The patent segments the power substrate into distinct regions with dedicated conductive traces for each paralleled power semiconductor die. This segmentation allows multiple die to be connected independently to the Kelvin connection contact and second power switching contact, reducing transconductance mismatches by ensuring equal connection lengths and impedances for each die while maintaining manageable layout complexity.
4Loss of energy
If metal length between second power switching contact and power semiconductor die is reduced, then impedance is reduced, but coupling with signal loop persists
Solution Approach 1:
The patent extracts the signal loop coupling by providing a completely separate conductive trace for the Kelvin connection contact that does not share metal pathways with the second power switching contact. This extraction eliminates the harmful coupling effect while the minimized metal length in each separate trace reduces impedance losses independently.
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 design improves switching performance by reducing coupling between power and signal loops, enhancing switching speed and stability, and simplifying the layout to accommodate multiple paralleled power semiconductor die without introducing additional inductance or area requirements.
Implementation Method 1
The Kelvin connection contact is coupled to the Kelvin connection pad of each one of the power semiconductor die via a Kelvin conductive trace on the power substrate
Implementation Method 2
The semiconductor structure is between the first power switching pad, the second power switching pad, and the control pad, and is configured such that a resistance of a power switching path between the first power switching pad and the second power switching pad is based on a control signal provided at the control pad
Data Source
AI summary
A package for power electronics includes a power substrate, a number of power semiconductor die, and a Kelvin connection contact. Each one of the power semiconductor die are on the power substrate and include a first power switching pad, a second power switching pad, a control pad, a semiconductor structure, and a Kelvin connection pad. The semiconductor structure is between the first power switching pad, the second power switching pad, and the control pad, and is configured such that a resistance of a power switching path between the first power switching pad and the second power switching pad is based on a control signal provided at the control pad. The Kelvin connection pad is coupled to the power switching path. The Kelvin connection contact is coupled to the Kelvin connection pad of each one of the power semiconductor die via a Kelvin conductive trace on the power substrate.