Vertically Stacked Direct Die Cooled Power Packages

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing liquid cooling methods for high power semiconductor devices are inefficient in managing high waste heat and ambient temperatures, particularly in direct die cooling where the heat transfer is not effectively distributed across semiconductor chips in stacked configurations.

Innovation Solution

A vertically stacked liquid cooled power electronic circuit is designed with direct die cooling, where each semiconductor power device package has both electrical and coolant interfacing, allowing for efficient heat transfer through vertically aligned fluid passages and re-orientable package configurations to maintain coolant flow while adjusting electrical interconnects.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If direct die cooling is implemented on a modular basis with stacked packages, then heat transfer efficiency is improved, but device complexity increases due to vertical stacking and interconnection requirements

Engineering Contradiction:
Improveheat transfer efficiencyVSAvoiddevice complexity
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The patent combines multiple cooling channels and electrical interconnects into a single integrated stacked package structure. The fluid distribution plate integrates multiple coolant channels that distribute cooling fluid to multiple semiconductor dies simultaneously, while electrical interconnects between stacked packages are formed through the same structural assembly process, merging thermal management and electrical connection functions into one unified device architecture.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent transitions from planar cooling arrangements to three-dimensional stacked packages. Multiple semiconductor dies are stacked vertically with cooling channels arranged in multiple layers and orientations (horizontal, vertical, inclined) to match the three-dimensional heat generation patterns. This dimensional transition allows heat to be extracted from multiple surfaces and depths of the stacked structure, significantly improving heat transfer efficiency while managing the increased complexity through systematic spatial organization.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Volume of moving object

If multiple semiconductor packages are vertically stacked for compact configuration, then space utilization is improved, but manufacturing precision requirements increase due to alignment of fluid passages and electrical interconnects

Engineering Contradiction:
Improvespace utilizationVSAvoidmanufacturing precision
Core Design Contradiction:
Volume of moving objectVSManufacturing precision

Solution Approach 1:

The patent incorporates alignment features and registration structures during the preliminary stages of package fabrication. The fluid distribution plate includes precisely positioned inlet and outlet ports that align with corresponding channels in stacked packages. Electrical interconnect structures are pre-formed with alignment tolerances built into the manufacturing process, allowing packages to be stacked and connected with reduced precision requirements during final assembly.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent introduces intermediate structural elements such as fluid distribution plates and alignment fixtures that mediate between individual packages during assembly. These intermediaries provide mechanical support, fluid distribution, and alignment references that reduce the direct precision requirements between stacked packages. The fluid distribution plate acts as an intermediary that distributes coolant to multiple dies through pre-aligned channels, while also serving as a mechanical interface that facilitates precise stacking.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Loss of energy

If coolant channels are integrated directly into semiconductor dies, then heat removal effectiveness is improved, but ease of manufacture decreases due to additional processing steps

Engineering Contradiction:
Improveheat removal effectivenessVSAvoidease of manufacture
Core Design Contradiction:
Loss of energyVSEase of manufacture

Solution Approach 1:

The patent segments the cooling function into separate modular components: semiconductor dies with integrated cooling channels, fluid distribution plates with inlet/outlet ports, and stacked package assemblies. This segmentation allows each component to be manufactured independently using optimized processes for that specific function, then assembled into the complete system. The segmentation reduces manufacturing complexity by avoiding the need to integrate all cooling features into a single monolithic structure.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent designs the fluid distribution plate to serve multiple functions: distributing coolant to multiple stacked dies, providing mechanical support for the stacked structure, facilitating alignment during assembly, and enabling fluid inlet/outlet connections. This multi-functionality reduces the total number of components needed and simplifies the manufacturing process by consolidating several functions into a single universal component rather than requiring separate specialized parts for each function.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 enhances heat transfer efficiency and flexibility in circuit configurations, enabling effective management of high waste heat and ambient temperatures in power electronic circuits, improving performance and reliability.

Implementation Method 1

The heat transfer can be significantly improved by bringing the liquid coolant directly into contact with the semiconductor chip (die)... the circulating fluid flows through the channels to remove heat from the chip

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 2

liquid coolant is circulated... flows through the channels to remove heat from the chip

Methodology Applied
Scientific EffectConvection: Convection

Data Source

PatentEP2001048B1Liquid Cooled Power Electronic Circuit Comprising Stacked Direct Die Cooled Packages
Publication Date: 2019.07.31 DELPHI TECH IP LTD
  • EP2001048B1 patent drawingFigure 1
  • EP2001048B1 patent drawingFigure 2A~5A
  • EP2001048B1 patent drawingFigure 4A~4E

AI summary

A plurality of direct die cooled semiconductor power device packages (60/60') arc vertically stacked with both coolant and electrical interfacing to form a liquid cooled power electronic circuit. The packages (60/60') arc individually identical, and selectively oriented prior to stacking in order to form the desired circuit connections and laterally stagger the package leads (36, 40, 42).