Beveled Semiconductor Die Fabrication for Thermal Stress Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Modern turbine engine ignition exciters face thermal performance limitations due to leakage current in switching devices, leading to power dissipation and potential device failure at elevated temperatures, and are hindered by costly semiconductor die manufacturing and packaging techniques.
Innovation Solution
The development of a semiconductor pulse switching device with a unique fabrication process involving angled saw blades for beveled surfaces, followed by etching to smooth damage, and a lead frame design that reduces thermal stress, along with a reliable output connector using O-rings for sealing, to enhance thermal performance and reduce manufacturing costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If conventional semiconductor die manufacturing and packaging techniques are used, then device functionality is achieved, but manufacturing costs are high
Solution Approach 1:
The patent divides the semiconductor wafer into multiple individual die using a saw blade, separating them into discrete components that can be individually packaged and assembled. This segmentation enables cost-effective manufacturing while maintaining device reliability through precise cutting and separation of functional units.
Solution Approach 2:
The patent introduces a beveled surface dimension on the semiconductor die by using an angled saw blade during the cutting process. This additional geometric dimension improves packaging efficiency and assembly reliability without increasing manufacturing complexity, allowing for better thermal management and electrical connection.
2Power
If semiconductor switching devices operate at elevated temperatures, then power output is maintained, but leakage current increases causing thermal runaway
Solution Approach 1:
The patent modifies the semiconductor device parameters including the addition of a beveled surface and optimized packaging structure that improves thermal dissipation characteristics. These parameter changes allow the device to maintain stable operation at elevated temperatures by reducing thermal runaway effects while preserving power output capability.
3Manufacturing precision
If precise wafer dicing is performed to separate individual die, then manufacturing precision is improved, but saw blade damage to die surfaces occurs
Solution Approach 1:
The patent applies a smoothing process to the die surfaces after sawing to remove damage caused by the cutting blade. This preliminary corrective action restores surface quality and eliminates potential reliability issues from surface defects while maintaining the precision benefits of accurate wafer dicing.
Solution Approach 2:
The patent converts the harmful effect of saw blade contact by using the cutting process to create a beveled surface that, while initially damaging, provides structural benefits for packaging and assembly. The subsequent smoothing process then eliminates the harmful surface defects, transforming the initial harm into a beneficial geometric feature.
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 significantly reduces leakage current, improves thermal performance by 40%, and lowers manufacturing costs, ensuring reliable operation and secure bonding of the semiconductor switching device in high-temperature turbine engine applications.
Implementation Method 1
the wafer is diced into individual circuit die by sawing the interface between adjacent die with a saw blade that has an angled configuration across its width, preferably in a generally V-shape so that the adjacent die are severed from one another
Implementation Method 2
Another embodiment of the present invention relates to the manner in which damage to the beveled side surface of the individual die can be smoothed by an etching process.
Implementation Method 3
a unique lead frame which can be soldered to another electrode metallization on the opposite side of the chip and the printed circuit board in a manner which substantially reduces if not eliminates harmful thermal stress
Implementation Method 4
a unique lead frame which can be soldered to another electrode metallization on the opposite side of the chip and the printed circuit board
Implementation Method 5
an output connector for interconnecting an exciter circuit product with a spark producing device wherein the output connector utilizes a configuration that includes a sealing structure that is reliable and easily installed
Data Source
AI summary
Fabrication processes for manufacturing and connecting a semiconductor switching device are disclosed, including an embodiment for dicing a wafer into individual circuit die by sawing the interface between adjacent die with a saw blade that has an angled configuration across its width, preferably in a generally V-shape so that the adjacent die are severed from one another while simultaneously providing a beveled surface on the sides of each separated die. Another embodiment relates to the manner in which damage to a beveled side surface of the individual die can be smoothed by a chemical etching process. Another embodiment relates to the manner in which the device can be easily mounted on a printed circuit board by providing conductive lands on the printed circuit board that are coextensive with metallized electrodes on the device and which can be placed on the printed circuit board and soldered in place and a unique lead frame which can be soldered to another electrode metallization on the opposite side of the chip and the printed circuit board in a manner which substantially reduces if not eliminates harmful thermal stress and which assures secure bonding notwithstanding elevation differences between the electrode metallization and the printed circuit board the lead frame is attached to. Another embodiment relates to an output connector for interconnecting an exciter circuit product with a spark producing device wherein the output connector utilizes a configuration that includes a sealing structure that is reliable and easily installed.