Semiconductor Light-Emitting Device With Edge-Extended Resin Layer
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional semiconductor light-emitting devices with wavelength converting layers face challenges in achieving uniform color tone and high contrast from small light-emitting surfaces, particularly when used in applications like vehicle headlights where light direction and color variability are critical.
Innovation Solution
The semiconductor light-emitting device design includes a semiconductor chip substrate with a reflective substrate, a semiconductor epitaxial layer, and a wavelength converting layer with a uniform thickness, where the wavelength converting layer is positioned between the epitaxial layer and the transparent resin layer, and the transparent resin layer extends from the wavelength converting layer to the edge of the chip substrate, forming a linear or convex shape to optimize light path and reduce color variability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a wavelength converting material is used to convert light from a semiconductor light-emitting chip, then light having a different light-emitting wavelength can be produced, but the color tone of the emitted light varies depending on the light-emitting direction due to different path lengths through the wavelength converting material
Solution Approach 1:
The patent applies local quality by creating different optical path lengths in different regions of the wavelength converting material. Specifically, the side surface of the wavelength converting material is positioned at a different distance from the semiconductor light-emitting chip compared to the top surface, resulting in longer light path lengths through the wavelength converting material at the side surfaces. This localized variation in path length compensates for the directional color tone variation, achieving more uniform color temperature across different emission directions.
2Illumination intensity
If the wavelength converting material is positioned to cover the semiconductor light-emitting chip, then wavelength conversion can be achieved, but the device occupies a larger area and the light-emitting surface is not minimized
Solution Approach 1:
The patent utilizes dimensional optimization by positioning the side surface of the wavelength converting material at a different depth (z-dimension) relative to the top surface. This three-dimensional arrangement allows the wavelength converting material to effectively cover the semiconductor chip for wavelength conversion while minimizing the projected light-emitting surface area in the x-y plane, thus resolving the contradiction between conversion efficiency and surface area minimization.
3Illumination intensity
If direct light from the semiconductor light-emitting chip reaches the side surface without passing through the wavelength converting material, then high intensity direct light is emitted, but color tone uniformity deteriorates
Solution Approach 1:
The patent implements preliminary anti-action by pre-positioning the side surface of the wavelength converting material such that it intercepts direct light from the semiconductor chip before the light can escape without conversion. By creating a longer optical path through the wavelength converting material at the side surfaces, the design proactively prevents direct unconverted light from reaching the observer, thereby maintaining color tone consistency while preserving sufficient light intensity.
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 the emission of a mixture light with a substantially uniform color tone from both the top and side surfaces, reducing color variability across different light-emitting directions and maintaining high contrast, suitable for applications like vehicle headlights.
Implementation Method 1
a wavelength converting layer 4 having a top surface 4T and a bottom surface 4B, and including at least one phosphor, formed on the top surface 2T of the semiconductor epitaxial layer 2
Implementation Method 2
a semiconductor chip substrate 1 with a reflective substrate
Data Source
AI summary
A semiconductor light-emitting device and a method for manufacturing the same can include a wavelength converting layer located over a semiconductor epitaxial layer in order to emit various colored-lights including white light. The light-emitting device can include a semiconductor chip substrate configured not to transmit light emitted from the epitaxial layer and mounted on a mounting board, and a transparent resin layer located between the wavelength converting layer and the epitaxial layer mounted on the semiconductor chip substrate so as to extend from a side surface of the wavelength converting layer towards a substantially edge portion of the semiconductor chip substrate. The semiconductor light-emitting device can be configured to improve a color variability of a mixture light emitted from the device by using the transparent resin layer and the wavelength converting layer, and therefore can emit the mixture light having a substantially uniform color tone from a small light-emitting surface.