Thick Bottom Metal Semiconductor Device Heat Dissipation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing power semiconductor devices face challenges in heat dissipation and high production costs due to thin metal electrodes, which affect electrical performance and accuracy in chip placement.
Innovation Solution
A method for forming semiconductor devices with a thick bottom metal layer, involving a process that includes depositing a metal layer on the back surface of thinned wafers, using lead frames with specific structures, and injecting plastic package material to encapsulate the devices, thereby exposing metal bumps for improved heat dissipation and mechanical strength.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a metal can is used to encapsulate the semiconductor chip, then heat dissipation is improved, but the cost of preparation increases and accurate placement becomes difficult
Solution Approach 1:
The patent replaces the expensive metal can with a plastic package housing that serves the same heat dissipation function. The plastic package is cheaper to manufacture and easier to work with during assembly, while still providing adequate thermal management through the exposed electrode design.
Solution Approach 2:
The plastic package housing serves multiple functions: it provides mechanical protection, enables heat dissipation through the exposed electrode, and facilitates accurate placement through integration with the lead frame. This multi-functional design eliminates the need for separate metal can components.
2Volume of moving object
If a thin metal electrode is used inside the plastic package, then the device structure is compact, but heat dissipation performance is poor
Solution Approach 1:
The patent extends the electrode in the vertical dimension by making it protrude from the plastic package housing. This dimensional extension provides a larger surface area for heat dissipation without increasing the horizontal footprint of the device, thus maintaining compactness while improving thermal performance.
Solution Approach 2:
The electrode is segmented into two functional parts: a thin portion inside the package for electrical connection and a thicker exposed portion outside the package for heat dissipation. This segmentation allows each part to be optimized for its specific function.
3Temperature
If the metal layer is made thicker to improve heat dissipation, then thermal performance improves, but the placement accuracy of the chip deteriorates
Solution Approach 1:
The electrode has different thicknesses at different locations: thin where it needs to be flexible for chip placement and thick where it needs to dissipate heat. This local variation in quality allows simultaneous optimization of placement accuracy and heat dissipation performance.
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 enhances heat dissipation and reduces production costs by ensuring accurate placement of semiconductor chips while maintaining mechanical strength, improving the overall performance of power semiconductor devices.
Implementation Method 1
depositing a metal layer on the back surface of thinned wafers
Implementation Method 2
injecting plastic package material to encapsulate the devices
Data Source
AI summary
A semiconductor device with thick bottom metal comprises a semiconductor chip covered with a top plastic package layer at its front surface and a back metal layer at its back surface, the top plastic package layer surrounds sidewalls of the metal bumps with a top surface of the metal bumps exposing from the top plastic package layer, a die paddle for the semiconductor chip to mount thereon and a plastic package body.