Semiconductor Laser Drive Device Wiring Inductance Reduction
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Solution Overview
Problem
In semiconductor laser drive devices, the integration of laser diode arrays and driver ICs results in increased wiring inductance, leading to distorted driving waveforms, particularly at high frequencies like hundreds of megahertz, which affects the accuracy of time-of-flight distance measurement systems.
Innovation Solution
A semiconductor laser drive device with a substrate-integrated laser driver and a semiconductor laser, where the connection wiring has a low inductance of 0.5 nH or less, and a passive component, such as a capacitor, is disposed to face the semiconductor laser with the least number of pads, reducing wiring length and noise, and a photodiode monitors light intensity to ensure proper laser operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the laser diode array and driver IC are integrated and electrically connected by wires, then the device complexity is reduced and integration is achieved, but the wiring inductance increases causing driving waveform distortion
Solution Approach 1:
The patent merges the driver IC and laser diode array into a single integrated optical module, reducing device complexity. The driver IC is mounted on the same substrate as the laser diode array, with electrical connections established through wire bonds or printed circuit board traces, achieving functional integration while managing the trade-off of increased wiring inductance through careful layout design.
2Reliability
If the wiring length between laser driver and semiconductor laser is reduced, then the wiring inductance is reduced improving waveform accuracy, but the device layout becomes more constrained
Solution Approach 1:
The patent utilizes three-dimensional packaging techniques and multi-layer substrate designs to reduce wiring length without constraining the two-dimensional layout. By routing connections through vertical vias and utilizing multiple substrate layers, the electrical path length is minimized while maintaining flexible planar arrangements of components.
3Reliability
If passive components are disposed to face the side of semiconductor laser with least pads, then the wiring length is shortened reducing inductance, but the manufacturing precision requirements increase
Solution Approach 1:
The patent applies different placement strategies for different components based on their specific requirements. Passive components are positioned to minimize wiring length to the laser diode array, while the driver IC and other components are arranged according to their electrical connection needs. This localized optimization approach reduces overall wiring inductance without uniformly increasing manufacturing precision requirements across all components.
Data Source
AI summary
In a semiconductor laser drive device, wiring inductance between a semiconductor laser and a laser driver is reduced. A substrate has a laser driver built inside. A semiconductor laser is mounted on one surface of a substrate of the semiconductor laser drive device and emits irradiation light from an irradiation surface. A connection wiring electrically connects the laser driver and the semiconductor laser with a wiring inductance of 0.5 nH or less. A passive component is disposed to face a side of the semiconductor laser having the least number of pads and connects to the semiconductor laser and the laser driver.