Semiconductor Device Chamfering via Pulsed Laser
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Solution Overview
Problem
Conventional semiconductor wafer cutting methods using dicing apparatus and laser processing result in devices with low die strength, leading to quality degradation in electrical equipment, with dicing apparatus achieving 800 MPa and laser processing achieving 400 MPa.
Innovation Solution
A device processing method involving the application of a pulsed laser beam with a pulse width of 2 ns or less and peak energy density between 5 to 200 GW/cm² to chamfer the periphery of semiconductor devices, optimizing the overlap rate and spot diameter of the laser beam for improved die strength.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If conventional laser processing method is used to divide semiconductor wafer, then division along grooves is achieved, but die strength is reduced to 400 MPa
Solution Approach 1:
The patent applies parameter changes by optimizing the pulsed laser beam parameters (pulse width of 2 ns or less, peak energy density of 5 to 200 GW/cm²) to achieve chamfering that improves die strength to 800 MPa or more, resolving the contradiction between division capability and strength maintenance
Solution Approach 2:
The chamfering step is performed as a preliminary action before final device separation, preparing the periphery with enhanced strength characteristics that prevent degradation during subsequent handling and assembly processes
2Strength
If dicing apparatus with cutting blade is used, then high die strength of 800 MPa is achieved, but mechanical complexity and operation difficulty increase
Solution Approach 1:
The patent replaces the mechanical cutting blade system with a pulsed laser beam system that achieves comparable die strength (800 MPa or more) through optical energy deposition, eliminating the complexity of high-speed rotating blades and mechanical bonding structures while maintaining strength through controlled laser-induced material modification
3Productivity
If conventional laser processing is used, then wafer division is achieved, but die strength is low at 400 MPa
Solution Approach 1:
The patent changes the laser processing parameters from conventional settings to ultra-short pulse width (2 ns or less) and high peak energy density (5 to 200 GW/cm²), which enables simultaneous achievement of efficient wafer division and high die strength (800 MPa or more) by controlling the energy deposition rate and material response
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 method enhances the die strength of semiconductor devices to 800 MPa or more, improving the quality of electrical equipment by effectively chamfering the device periphery with the specified pulsed laser beam parameters.
Implementation Method 1
applying a pulsed laser beam having an absorption wavelength to the device along the periphery of the device to thereby chamfer the periphery of the device
Implementation Method 2
pulsed laser beam having an absorption wavelength
Data Source
AI summary
A device processing method for improving the die strength of a device divided from a semiconductor wafer. The device processing method includes a chamfering step of applying a pulsed laser beam having an absorption wavelength to the device along the periphery of the device to thereby chamfer the periphery of the device, wherein the pulse width of the pulsed laser beam to be applied in the chamfering step is set to 2 ns or less, and the peak energy density is set in the range of 5 to 200 GW/cm2.