Light Source Device Substrate Warping Prevention
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Solution Overview
Problem
In light source devices with semiconductor lasers, the use of adhesive-free solid phase diffusion connections can lead to warping and bending due to uneven compressive loads on the substrate and side wall portions with inclined reflection surfaces, compromising structural stability.
Innovation Solution
A light source device design featuring a substrate, semiconductor laser, and a side wall portion with inclined inner surfaces acting as a reflection surface, where the upper surface of the substrate and lower surface of the side wall portion are connected via a connecting layer over the entire periphery, ensuring even compressive stress distribution and preventing warping and bending.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If solid phase diffusion connection is performed without adhesive agent, then connection stability is improved, but warping and bending occur due to uneven compressive load distribution
Solution Approach 1:
The invention introduces a reinforcing structure specifically at the lower surface of the side wall portion where compressive load is applied. This localized reinforcement creates different structural properties in different regions: the lower surface has enhanced support capability while the upper surface maintains its original design for light extraction. This resolves the contradiction by providing local structural strengthening exactly where needed to prevent warping during compression bonding.
Solution Approach 2:
The invention creates an asymmetric structure by adding a reinforcing element only at the lower surface of the side wall portion, not at the upper surface. This asymmetric design addresses the uneven compressive load distribution by providing reinforcement specifically at the compression point, allowing stable adhesive-free bonding without causing warping or bending of the semiconductor laser element.
2Strength
If compressive load is applied for solid phase diffusion connection, then connection strength is improved, but bending stress causes warping and bending
Solution Approach 1:
The reinforcing structure at the lower surface of the side wall portion acts as a counterbalancing element that resists the bending moment generated during compressive loading. This reinforcement provides structural support that counteracts the warping tendency, allowing the application of necessary compressive load for strong bonding without suffering from excessive bending stress.
3Productivity
If inclined reflection surface is used, then beam extraction efficiency is improved, but uneven load distribution causes warping and bending
Solution Approach 1:
The invention maintains the inclined reflection surface for optimal beam extraction efficiency while adding localized reinforcement at the lower surface of the side wall portion. This local structural enhancement specifically addresses the load distribution issue caused by the inclined surface geometry, allowing the inclined surface to function optimally for light extraction while the reinforcement prevents warping and bending under compressive load.
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 effectively suppresses warping and bending in the substrate and side wall portion, even under compressive loads, while maintaining airtight and firm connections, enhancing the durability and beam extraction efficiency of the light source device.
Implementation Method 1
The connection without using an adhesive agent includes solid phase diffusion connection between metal layers
Implementation Method 2
at least a part of the inner side surfaces serves as a reflection surface for reflecting a beam emitted from the semiconductor laser toward the cover
Data Source
AI summary
There is provided a light source device comprising a substrate; a semiconductor laser placed on the substrate; a side wall portion formed so as to surround the semiconductor laser; and a cover being translucent, configured to cover a space surrounded by the substrate and the side wall portion, wherein the side wall portion includes a lower surface connected to an upper surface of the substrate over a whole periphery, an upper surface connected to a lower surface of the cover over a whole periphery, and inner side surfaces inclined so that the space expands from a lower surface side to an upper surface side of the side wall portion, at least a part of the inner side surfaces serving as a reflection surface for reflecting a beam emitted from the semiconductor laser toward the cover, and a connecting portion where an upper surface of the substrate and a lower surface of the side wall portion are in contact with each other via a connecting layer is provided in a region corresponding to an upper surface of the side wall portion in a plan view from above.