Semiconductor Light Emitting Device Inner-Layer Wire Positioning
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Solution Overview
Problem
The absorption of light by inner-layer wires in semiconductor light emitting devices reduces the light extraction efficiency due to the use of black or dark-colored wires and the porous, translucent nature of ceramic substrates, leading to significant optical losses.
Innovation Solution
The inner-layer wire is positioned outside the outer peripheral region of the semiconductor light emitting element, and the package structure includes a two-layer insulating layer configuration with conductive wires on the upper face and an inner-layer wire embedded between these layers, preventing light absorption and enhancing light extraction efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If inner-layer wire is embedded in ceramic substrate, then electrical connection is achieved, but light absorption increases and light extraction efficiency decreases
Solution Approach 1:
The patent extracts the harmful element (inner-layer wire) from the light transmission path by positioning it outside the ceramic substrate, specifically on the rear face away from the light emitting element. This removes the wire's light-absorbing effect while preserving its electrical connection function.
Solution Approach 2:
The patent introduces an intermediary structure (convex lens formed from transparent resin) between the light emitting element and the environment. This convex lens serves as a mediator that extracts and directs light while the inner-layer wire remains positioned on the rear face, separated from the light path by this intermediary element.
2Device complexity
If inner-layer wire is positioned close to light emitting element, then wiring space is optimized, but light absorption by wire increases
Solution Approach 1:
The patent resolves the spatial conflict by moving the inner-layer wire to a different dimensional plane - specifically the rear face of the ceramic substrate, which is spatially separated from the front face where the light emitting element is located. This z-axis separation eliminates light absorption while maintaining wiring functionality.
3Temperature
If ceramic substrate is used for heat resistance, then thermal stability is improved, but light transmission is reduced due to porosity
Solution Approach 1:
The patent segments the package structure into distinct functional zones: the ceramic substrate handles thermal management and structural support, while the transparent resin convex lens handles light extraction. This segmentation allows each material to optimize its primary function without compromise.
Solution Approach 2:
The patent makes the package structure multi-functional by having different components serve different purposes: the ceramic substrate provides heat resistance and mechanical strength, while the transparent resin convex lens provides light extraction. This multi-functionality resolves the contradiction between thermal and optical requirements.
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 increases the light emission efficiency by minimizing light absorption by the inner-layer wire, resulting in a 6% increase in light flux extraction compared to conventional designs.
Implementation Method 1
the wires may absorb light from the light emitting element... some of the light emitted from the light emitting diode may be transmitted through the ceramic and absorbed by the inner-layer wire embedded in the ceramic
Data Source
Figure 1A~1C
Figure 2
Figure 3A
AI summary
A semiconductor light emitting device, has a package constituted by the lamination of a first insulating layer having a pair of positive and negative conductive wires formed on its upper face, an inner-layer wire below the first insulating layer, and a second insulating layer below the inner-layer wire; a semiconductor light emitting element that has a pair of positive and negative electrodes on the same face side and that is disposed with these electrodes opposite the conductive wires; and a sealing member that covers the semiconductor light emitting element, wherein part of the conductive wires is formed extending in the outer edge direction of the sealing member from directly beneath the semiconductor light emitting element, on the upper face of the first insulating layer, and is connected to the inner-layer wire via a conductive wire disposed in the thickness direction of the package, and the inner-layer wire is disposed so as to be spaced apart from the outer periphery of the semiconductor light emitting element in a see-through view of the package from the upper face side of the first insulating layer.