Laser Diode Bar Singulation for Stress-Free Carrier Alignment
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Solution Overview
Problem
Laser bar components experience semilunate bending due to internal stress when mounted on carriers, leading to deviations in light-emitting regions and polarization changes, and individual diode chip mounting requires large carriers, increasing production complexity and reducing fill factor.
Innovation Solution
A method involving a semiconductor wafer with a semiconductor layer sequence and multiple diode elements connected mechanically, where thermally induced breaking locations are created using laser radiation to separate the diode elements, allowing them to be arranged straight on a carrier with reduced stress, improving optical properties and enabling self-singulation without additional steps.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If laser bars are mounted on carriers as individual diode chips, then internal stresses are reduced and semilunate bending is avoided, but carrier size increases and fill factor decreases
Solution Approach 1:
The laser bar is segmented into multiple individually mountable diode chip units, each with its own electrical contact regions. This segmentation allows each chip to be mounted independently on the carrier, reducing internal stresses and preventing semilunate bending while maintaining a compact overall structure that optimizes the fill factor.
2Shape
If laser bars are bent back into a straight line to avoid semilunate bending, then alignment is improved, but edge regions experience large stresses causing polarization change
Solution Approach 1:
The diode chips are pre-cut from the laser bar and pre-aligned in a straight line configuration before mounting on the carrier. This preliminary action ensures that the chips are already in the desired straight line alignment, eliminating the need for post-mounting bending operations that would induce harmful stresses and polarization changes in the edge regions.
3Stability of the object's composition
If individual diode chips are mounted on carriers, then internal stresses are reduced, but production complexity and adjustment outlay increase
Solution Approach 1:
The patent employs universal mounting structures and standardized electrical contact regions that can accommodate multiple diode chip configurations. The carrier design includes universal contact pads and mounting features that work with various chip arrangements, simplifying the production process and reducing adjustment outlay while maintaining reduced internal stresses through individual chip mounting.
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
This approach reduces internal stresses, aligns diode elements in a straight line, enhances optical properties, and increases the usable area by allowing the edge regions to function as light-emitting regions, reducing production complexity and increasing efficiency.
Implementation Method 1
generating thermally induced predetermined breaking locations in the semiconductor layer sequence between the single diode elements using laser radiation
Implementation Method 2
The laser radiation leads to thermally induced mechanical stress in desired separating regions
Data Source
AI summary
In an embodiment a method includes providing at least one semiconductor wafer, which has a semiconductor layer sequence and a plurality of single diode elements arranged next to and connected to one another, generating thermally induced predetermined breaking locations in the semiconductor layer sequence between the single diode elements using first laser radiation, arranging the semiconductor wafer on a carrier, and connecting the semiconductor wafer to the carrier, the single diode elements being at least partially separated from one another at the thermally induced predetermined breaking locations, wherein thermally induced predetermined breaking locations are generated in the carrier using second laser radiation so that the carrier has a plurality of carrier elements connected to one another, and wherein the carrier elements are separated from one another at the predetermined breaking locations by a connecting process.