SMD Package Heat Spreader Top Surface Area
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing surface-mount device (SMD) packages with top side cooling face challenges in effective heat dissipation due to electrical insulation materials that dampen heat transfer, while needing to maintain safety clearances and creepage lengths.
Innovation Solution
A package design with a heat spreader having a larger top surface area than its bottom surface, electrically connected to the top layer, which is also connected to the power semiconductor die, allowing for enhanced heat dissipation while ensuring electrical insulation and safety compliance through a profiled design that maintains necessary clearances.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If electrical insulation materials are used between the heat spreader and top layer, then safety requirements regarding clearance distance and creepage length are met, but heat transfer efficiency deteriorates
Solution Approach 1:
The patent removes the electrical insulation material from between the heat spreader and top layer. Instead, the heat spreader is electrically connected to the top layer through a conductive connection, while safety clearances are maintained through the profiled design of the heat spreader itself, eliminating the thermal barrier caused by insulation materials
Solution Approach 2:
The patent introduces a conductive connection as an intermediary between the heat spreader and top layer, replacing the electrical insulation material. This conductive intermediary allows both efficient heat transfer and electrical connection while maintaining safety clearances through the geometric design
2Reliability
If heat dissipation device is coupled to top layer with electrical insulation, then safety requirements are fulfilled, but cooling performance deteriorates
Solution Approach 1:
The patent removes electrical insulation materials from the heat dissipation path between the heat spreader and heat dissipation device. The heat spreader directly contacts the heat dissipation device, eliminating thermal resistance while safety clearances are maintained through the profiled geometry of the heat spreader
Solution Approach 2:
The heat spreader is designed with different surface areas at different locations - a larger top surface area for heat dissipation contact and a smaller bottom surface area for electrical connection. This local variation in geometry optimizes both thermal and electrical performance while maintaining safety clearances
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 design improves heat transfer efficiency by increasing the heat spreader's top surface area, enhancing cooling performance while meeting safety requirements, thus effectively managing heat dissipation in SMD packages.
Implementation Method 1
a heat spreader arranged external of the package body and in electrical contact with the top layer with a bottom surface of the heat spreader facing to the top layer, wherein the heat spreader further has a top surface, the area of the top surface being greater than the area of the bottom surface
Data Source
AI summary
A package encloses a power semiconductor die and has a package body with a top side, footprint side and sidewalls. The die has first and second load terminals and blocks a blocking voltage between the load terminals. The package further includes: a lead frame structure for electrically and mechanically coupling the package to a support, the lead frame structure including an outside terminal extending out of the package footprint side and/or out of one of the package sidewalls and electrically connected with the first load terminal; and a top layer arranged at the package top side and electrically connected with the second load terminal. A heat spreader is mounted onto the top layer with a bottom surface facing the top layer. The area of the top surface of the heat spreader is greater than the area of the bottom surface.