Stackable Surface-Mount Power Package With 3D Leadframe Cooling
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Solution Overview
Problem
Existing stackable electronic power devices face challenges in high heat dissipation, especially in simpler circuits and high-power applications, where prior solutions are complex or inefficient.
Innovation Solution
A packaged electronic power device with a leadframe configuration that allows for both upward and downward heat dissipation, featuring a DBC multilayer leadframe with projecting leads and a die-attach support for efficient thermal management, enabling the stacking and connection of multiple devices for enhanced thermal and electrical performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a DBC multilayer leadframe with side-by-side die arrangement is used, then circuit topology flexibility is improved, but device area increases
Solution Approach 1:
The patent transitions from a two-dimensional side-by-side die arrangement to a three-dimensional stacked arrangement. Multiple dies are vertically positioned on different levels of the DBC multilayer leadframe, connected via wire bonds that traverse through insulating layers. This vertical stacking enables complex circuit topologies (half-bridge, full-bridge, A.C. switch) while maintaining a compact footprint, directly resolving the contradiction between circuit flexibility and device area.
2Ease of manufacture
If leads are arranged on the same side of the dissipation structure, then manufacturing simplicity is improved, but heat dissipation capability deteriorates
Solution Approach 1:
The patent segments the leadframe into multiple electrically insulated levels within the DBC multilayer structure. Each level can independently support dies and provide heat dissipation pathways. The dissipation structure is divided into multiple dissipation surfaces at different heights, allowing heat to be dissipated from multiple locations simultaneously, thereby improving heat dissipation capability while maintaining manufacturing feasibility through modular construction.
3Adaptability or versatility
If multiple dice are arranged side by side, then circuit configuration flexibility is improved, but required area increases
Solution Approach 1:
The patent implements a vertical stacking architecture where multiple dies are arranged on different vertical levels rather than side by side. The DBC multilayer leadframe provides insulating barriers between levels, allowing dies to be positioned vertically above one another. This three-dimensional arrangement enables complex circuit configurations (such as half-bridge and full-bridge topologies) to be achieved within a compact footprint, directly resolving the contradiction between circuit configuration flexibility and required area.
4Temperature
If a complex multilayer support structure is used for stacking, then heat dissipation is improved, but device complexity increases
Solution Approach 1:
The DBC multilayer leadframe serves multiple functions simultaneously: it provides mechanical support for stacking dies, electrical insulation between different circuit nodes, thermal conduction pathways for heat dissipation, and structural framework for wire bonding connections. By integrating these multiple functions into a single multilayer structure, the patent achieves improved heat dissipation without proportionally increasing device complexity, as the same structural elements fulfill multiple roles.
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 provides improved thermal dissipation capabilities, allowing for stable stacking and connection of devices, increasing electrical performance and enabling complex circuit configurations while maintaining cost-effectiveness.
Implementation Method 1
a packaged electronic power device with a leadframe configuration that allows for both upward and downward heat dissipation, featuring a DBC multilayer leadframe with projecting leads and a die-attach support for efficient thermal management
Data Source
Figure 1~3
Figure 4~7
Figure 7A~8
AI summary
The power device for surface mounting has a leadframe (15) including a die-attach support (24C) and at least one first lead (4B) and one second lead (4C). A die (6), of semiconductor material, is bonded to the die-attach support, and a package (2), of insulating material and parallelepipedal shape, surrounds the die and at least in part the die-attach support (24C) and has a package height (H1). The first and second leads (4B, 4C) have outer portions (14B, 14C) extending outside the package (2), from two opposite lateral surfaces (2C, 2D) of the package. The outer portions of the leads have lead heights (H2) greater than the package height (H1), extend throughout the height of the package, and have respective portions projecting from the first base (2A).