Reflective Potting for Optoelectronic Semiconductor Emission Efficiency
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Solution Overview
Problem
Optoelectronic semiconductor components face challenges in achieving high emission efficiency, with a significant portion of generated radiation being coupled out via transparent substrates rather than the active semiconductor layer sequence, leading to reduced directed emission and potential absorption on the carrier.
Innovation Solution
The use of a reflective potting material surrounding the semiconductor chip, which reflects diffusely and is in direct contact with the chip, increases emission efficiency by reflecting radiation back into the substrate and decoupling it from the chip, while a conversion medium can further convert radiation wavelength and reduce emission angles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If a transparent substrate is used for the semiconductor chip, then the substrate allows radiation to pass through, but a significant portion of generated radiation leaves the chip via the substrate rather than being directed usefully
Solution Approach 1:
The patent applies a reflective coating on the rear side of the transparent substrate to capture radiation that would otherwise be lost through the substrate. This converts the harmful effect of radiation loss into a beneficial reflection back toward the active layer, improving overall emission efficiency while maintaining the advantages of transparent substrates.
Solution Approach 2:
The patent introduces a vertical dimension solution by applying reflection coating on the rear side of the substrate, capturing radiation in the downward direction and redirecting it upward toward the active layer. This dimensional approach to radiation management improves emission control without affecting the lateral operation of the device.
2Productivity
If radiation is emitted from the substrate, then the emission is distributed over the entire chip surface, but the emitted radiation is comparatively undirected and can be absorbed on the carrier
Solution Approach 1:
The reflective coating on the substrate rear side captures radiation that would otherwise be lost to the carrier and convert it back into useful emission. This transforms the harmful absorption by the carrier into a beneficial feedback loop that increases overall luminous flux.
3Power
If the semiconductor layer sequence is based on III-V compound semiconductor material, then the active layer can generate electromagnetic radiation efficiently, but the crystal lattice and high thermal conductivity of substrate materials make them transparent to radiation
Solution Approach 1:
The patent acknowledges that the transparency of III-V compound semiconductor substrates causes radiation loss, but converts this disadvantage into an advantage by applying reflective coatings on the rear side. This allows the substrate to maintain its excellent thermal and electrical properties while preventing radiation loss through reflection.
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 configuration enhances the emission efficiency of the semiconductor component by increasing the directed emission of radiation and reducing absorption on the carrier, resulting in improved luminous flux and emission angle control.
Implementation Method 1
The semiconductor component has a reflective potting material. Reflective means that the potting material has a reflectivity for radiation in the visible spectral range of in particular more than 80% or more than 90%, preferably more than 94%. The potting material preferably reflects diffusely.
Implementation Method 2
a conversion medium can further convert radiation wavelength and reduce emission angles
Data Source
Figure 1~3
Figure 4~7
Figure 8A~11
AI summary
In at least one embodiment of the optoelectronic semiconductor component (1), said component contains a carrier (2) having an upper substrate upper (20). At least one optoelectronic semiconductor chip (3) is arranged on the upper carrier face (20). The semiconductor chip (3) comprises a semiconductor layer sequence (32) having at least one active layer for generating electromagnetic radiation and a radiation-permeable substrate (34). Furthermore, the semiconductor component (1) comprises a reflective potting compound (4) which, starting from the upper carrier face (20), completely surrounds the semiconductor chip (3) in a lateral direction at least up to half the height of the substrate (34).