Surface-Mounted VCSEL Illuminator With Integrated Nano-Imprinted Diffuser
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Solution Overview
Problem
Existing VCSEL-based flood illuminators have a large package size due to the need for a housing with sidewalls to support the diffuser, which is not suitable for compact applications and harsh environments, and lack an integrated beam shaping diffuser for proper illumination.
Innovation Solution
A compact chip-scale package (CSP) flood illuminator design with a nano-imprinted diffuser structure on a substrate, using a VCSEL die encased in a potting resin and a polymer layer, eliminating the need for sidewalls and allowing for a smaller form factor and integrated beam shaping.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a housing with sidewalls is used to support the diffuser, then the diffuser is protected and structural integrity is maintained, but the package size becomes too large
Solution Approach 1:
The invention removes the housing sidewalls from the structure, extracting only the essential protective function while eliminating the volume-consuming enclosure. The diffuser is supported directly on the substrate without requiring sidewall support, thereby reducing package size while maintaining structural integrity through alternative means.
Solution Approach 2:
The diffuser support function is merged with the substrate itself. Instead of using separate housing sidewalls to support the diffuser, the substrate serves dual purposes: as the mounting platform for the VCSEL and as the support structure for the diffuser, eliminating redundant structural elements.
2Reliability
If the diffuser is positioned at a minimum distance away from the VCSEL apertures, then the diffuser functions properly, but the housing requires a larger package
Solution Approach 1:
The invention transitions from a three-dimensional housing structure to a two-dimensional planar configuration. The diffuser is positioned in the same plane as the VCSEL aperture on the substrate surface, eliminating the need for vertical spacing and housing depth, thereby significantly reducing package volume while maintaining diffuser functionality.
3Reliability
If a robust structure is used to protect the diffuser from cracking or detachment, then reliability in harsh environments is improved, but the package size increases
Solution Approach 1:
The invention uses a thin film or coating approach where the diffuser is integrated directly onto the substrate surface. This thin-film integration provides robust protection against cracking and detachment without requiring thick housing walls, maintaining reliability in harsh environments while keeping the package compact.
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 design achieves a smaller illuminator size of 0.5 mm×0.5 mm, providing a robust and cost-effective solution with integrated beam shaping, suitable for compact applications and harsh environments.
Implementation Method 1
The VCSEL die is mounted in electrical communication with the top electrodes and is configured to emit laser illumination
Implementation Method 2
the diffuser structure is nano-imprinted in the encasement adjacent the VCSEL die
Data Source
AI summary
VCSEL-based flood illuminators are fabricated to be compact and surface-mounted devices. A substrate is constructed as a panel array having top and bottom electrodes. Individual ones of the VCSEL dies are mounted in electrical communication with pairs of the top electrodes. The VCSEL dies are encased in an encasement disposed on the top surface of the substrate, and a diffuser structure is nano-imprinted adjacent each of the VCSEL dies. The encasement can use a potting resin and a polymer layer. The potting resin encases the VCSEL dies. The polymer layer is softer and is disposed on the potting resin. Nanoimprint lithography forms the diffuser structures in the polymer layer. The panel array is then singulated to form the individual VCSEL-based flood illuminators.