Flat Heat Pipe Embedded in PCB for Chip-on-Chip Power Device Cooling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional power control units (PCUs) face challenges with high power loss and low power density due to the design of power cards, which generate significant heat during high-frequency switching, and struggle with effective cooling, especially in chip-on-chip configurations where heat extraction between vertically stacked power devices is difficult.
Innovation Solution
The integration of flat heat pipes within the PCB substrate, positioned between vertically stacked power device stacks, facilitates direct heat transfer from the power devices to a condenser, enhancing cooling efficiency and reducing thermal resistance, thereby improving power density and reducing switching losses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If power devices are arranged in conventional surface-mounted configurations, then cooling is simplified, but power density decreases and system volume increases
Solution Approach 1:
The patent transitions from conventional surface-mounted power device arrangements to a vertical three-dimensional stacked configuration. Multiple power devices are arranged in vertical columns stacked along the Z-axis, enabling higher power density within the same footprint while maintaining effective cooling through embedded heat pipes that extract heat from each stacked device independently.
2Ease of operation
If power devices are mounted extending from the driver board, then connection is simplified, but system loop inductance increases and power loss increases
Solution Approach 1:
The patent integrates the power devices directly onto the driver board substrate in a chip-on-chip stacked configuration, eliminating separate mounting structures and extending pins. This merging of power devices with the driver board reduces system loop inductance and minimizes power losses while maintaining simplified electrical connections through integrated trace routing.
3Quantity of substance
If heat extraction is implemented in chip-on-chip configurations, then power density increases, but heat extraction between vertically stacked power devices becomes difficult
Solution Approach 1:
The patent introduces flat heat pipes as intermediary thermal management components embedded within the driver board substrate between the vertically stacked power devices. These heat pipes serve as thermal mediators that efficiently extract heat from multiple stacked devices through direct thermal contact, conducting heat laterally and removing it through integrated cooling channels, thus solving the heat extraction challenge in high-density stacked configurations.
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 configuration enables more efficient heat removal, maintaining lower running temperatures and higher power output, with reduced system volume and weight, and lower costs, while minimizing inductance and thermal resistance, thus addressing the limitations of traditional cooling methods.
Implementation Method 1
chip-on-chip PCB stacks having embedded heat pipes positioned between the chips to facilitate the extraction of heat within the chip-on-chip PCB stack
Implementation Method 2
one surface of the flat heat pipe directly bonded to a first one of the power device stacks and an opposite surface of the flat heat pipe thermally coupled to a second one of the power device stacks
Implementation Method 3
a flat heat pipe having an evaporator end and a condenser end opposite the evaporator end, the evaporator end positioned between the power device stacks
Implementation Method 4
facilitate the extraction of heat within the chip-on-chip PCB stack
Implementation Method 5
a thermally conductive via comprising a first end and a second end opposite the first end, the first end extending from a surface of the PCB substrate to the condenser end of the flat heat pipe and coupled to the flat heat pipe
Data Source
AI summary
Printed circuit board (PCB) substrates include at least one pre-preg layer interposed between one or more electrically conductive layers, power device stacks, each having a power device embedded within the PCB substrate in a vertical stack configuration, and a flat heat pipe positioned between the power device stacks within the at least one pre-preg layer, one surface of the flat heat pipe directly bonded to a first one of the power device stacks and an opposite surface of the flat heat pipe thermally coupled to a second one of the power device stacks.