PCB Power Distribution Network Optimization via Local Quality
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Solution Overview
Problem
In high current systems on printed wiring boards, voltage drops and non-uniform terminal current distribution lead to increased power dissipation and the need for over-specified connectors, due to the finite conductivity of metal layers and disparate current paths.
Innovation Solution
A method for designing a power distribution system on PCBs involves receiving a cross-section file with power sink and source locations, creating an initial power distribution system, evaluating it against a cost function, iteratively modifying the system to minimize voltage drops and power dissipation by reassigning power domains, and terminating when the cost function meets a stop criterion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If large metal areas are used for power planes to reduce voltage drop, then voltage drop is reduced, but differential voltages between terminals increase due to non-uniform current distribution
Solution Approach 1:
The patent applies local quality by varying the metal trace width throughout the power distribution network. Traces carrying higher current are made wider to reduce resistance and voltage drop in those specific regions, while traces carrying lower current are made narrower. This non-uniform trace width distribution optimizes current carrying capacity locally throughout the power plane, addressing both the voltage drop and differential voltage issues.
2Power
If multiple connector pins are used in parallel to carry high current, then current handling capacity increases, but power dissipation in connectors increases due to pin resistance
Solution Approach 1:
The patent changes the geometric parameters of the power distribution traces, specifically varying the trace width to optimize current distribution. By adjusting the trace width parameter throughout the power network, the system achieves more uniform current distribution across multiple parallel connector pins, thereby reducing the I²R power dissipation while maintaining the required current handling capacity.
3Volume of moving object
If thin laminated PWBs with many layers are used, then space efficiency increases, but effective resistance of power paths increases leading to higher terminal current disparity
Solution Approach 1:
The patent applies local quality by implementing non-uniform trace widths in the power distribution network within the thin laminated PWB structure. This allows optimization of current carrying capacity in specific high-current regions without increasing overall PWB thickness, thereby maintaining space efficiency while improving power distribution uniformity and reducing terminal current disparity.
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 results in an efficient power distribution system that minimizes voltage drops and power dissipation, optimizing current distribution and reducing the need for over-specified connectors, thereby enhancing the overall performance and efficiency of power delivery on PCBs.
Implementation Method 1
provide power paths or power planes for interconnecting the components to power supplies
Implementation Method 2
a significant amount of power is dissipated in the connectors due to pin resistance and in the PWBs themselves due to the finite conductivity of the metal layers
Data Source
AI summary
A method for designing a power distribution system including: receiving a cross section file that contains the layout of a PCB including a location of one or more power sinks and sources on the PCB; creating an initial power distribution system; evaluating the initial power distribution system against a cost function; creating a new power distribution system; evaluating the new power distribution system against the cost function; determining if the cost function associated with the new power distribution system is equal to or greater than a stop criterion; and creating another new power distribution system if the cost function associated with the new power distribution system is greater than the stop criterion.