Vertical Laser Diode Stack Carrier with Insulated Metallic Regions
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Solution Overview
Problem
Existing laser radiation sources with vertically stacked laser diode elements face issues such as thermo-mechanical stresses and distance fluctuations due to thickness variations in diode bars and substrate layers, leading to complex and inaccurate assembly processes.
Innovation Solution
A laser radiation source design featuring a stack of laser diode elements with substrate layers of opposite polarity connected via metallic layer regions, allowing for precise equidistant positioning and reducing mechanical stress through a carrier with a multi-layer structure, including copper and ceramic layers for thermal conductivity and electrical insulation, and a microcooler for cooling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If laser diode bars are connected directly via electrically conductive substrate layers to form a vertical stack, then electrical connection is achieved, but thermo-mechanical stresses occur and distance fluctuations arise due to thickness variations
Solution Approach 1:
The patent introduces an electrically insulating layer between the electrically conductive substrate layers of adjacent laser diode bars. This intermediary layer prevents direct thermal and mechanical contact while maintaining electrical connectivity through the substrate layers, thereby eliminating thermo-mechanical stresses that would otherwise occur at the interface between conductive layers.
Solution Approach 2:
The patent segments the electrically conductive substrate layers into separate, non-contacting layers for adjacent laser diode bars. Instead of having continuous conductive contact between bars, each substrate layer is electrically isolated from its neighbors through the insulating layer, allowing independent positioning and reducing stress accumulation across the stack.
2Device complexity
If laser diode bars are connected directly via substrate layers, then assembly is simplified, but distance fluctuations occur due to thickness variations in bars and substrate layers
Solution Approach 1:
The electrically insulating layer acts as a mediator that decouples the distance relationship between adjacent laser diode bars from the thickness variations of the conductive substrate layers. Since the insulating layer is not in direct thermal contact with the bars, its thickness can be controlled independently, providing a stable reference for equidistant positioning without requiring precise control of the conductive substrate layer thicknesses.
3Reliability
If insulation elements are introduced between substrate layers and carrier, then electrical insulation is provided, but the same disadvantages of stress and distance fluctuations persist
Solution Approach 1:
The patent extracts the electrical insulation function from the thermal contact path. Instead of placing insulation elements between the substrate layers and the carrier (which would interrupt thermal conduction), the insulation is implemented between the conductive substrate layers of adjacent bars, separating the electrical insulation function from the thermal management function.
Solution Approach 2:
The patent segments the insulation function to apply only where electrical isolation is needed (between adjacent conductive substrate layers) while maintaining continuous thermal contact between each bar's substrate and the carrier. This selective segmentation allows electrical insulation without compromising thermal management.
4Manufacturing precision
If a voluminous carrier with grooves is used to accommodate laser diode bars, then positioning is enabled, but production becomes complex and accuracy is limited
Solution Approach 1:
The patent replaces the mechanical groove-based positioning system with a planar surface system. Instead of cutting complex grooves into a voluminous carrier, the invention uses a flat carrier surface with integrated electrically insulating layers that provide both positioning reference and electrical isolation, simplifying the manufacturing process while maintaining positioning accuracy.
Solution Approach 2:
The electrically insulating layer serves as an intermediary that combines the positioning reference function with the electrical isolation function. This single layer replaces the need for separate mechanical positioning features (grooves) and insulation elements, reducing manufacturing complexity.
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 design enables a power-scalable, low-stress, and precise assembly of laser diode elements with improved thermal conductivity and reduced component complexity, eliminating the need for screw connections and outgassing materials, while allowing for simple scaling and efficient heat dissipation.
Implementation Method 1
substrate layers of opposite polarity of adjacent laser diode elements being applied to common layer regions of a metallic layer
Implementation Method 2
at least one first flat, multi-layer plate-shaped carrier, which consists of a first and at least one second metallic layer, which are separated by at least one electrically insulating layer made of non-metallic material
Implementation Method 3
at least one electrically insulating layer made of non-metallic material
Implementation Method 4
a microcooler for cooling
Data Source
Figure 1
Figure 2~5
Figure 6
AI summary
A laser radiation source which can be scaled in terms of power is intended to be designed such that laser diode elements can be stacked equidistantly with little manufacturing complexity and can be applied to a carrier with little stress. The laser radiation source contains a vertical stack of laser diode elements (1), with which contact is made on both sides via electrically conductive substrate layers (2, 3), and a multilayer carrier (4), which comprises a first and a second metallic layer (5, 6), which are separated by at least one electrically insulating layer (7) consisting of a nonmetallic material. At least one of the metallic layers is divided into metallic layer regions (8), which are arranged next to one another and at a distance from one another. Substrate layers of adjacent laser diode elements (1), which substrate layers are of opposite polarity, are applied to common layer regions of a metallic layer (8). Collimator lenses (11) serve the purpose of collimating the radiation emitted by the laser diode elements (1).