Substrate-Free Semiconductor Light-Emitting Device for Uniform Color
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Solution Overview
Problem
Semiconductor light-emitting devices with chip-size package structures require high reliability but face challenges in achieving efficient light extraction and heat dissipation due to the presence of a substrate, which can lead to color degradation and unevenness, as well as contamination risks from metal migration.
Innovation Solution
A semiconductor light-emitting device design featuring a phosphor layer on the light extraction side without a substrate, with a resin layer and reflection film on the mounting surface to enhance light extraction, reduce substrate-related issues, and prevent metal contamination, while using a complex of metal pillars and resin for support, allowing for improved stress relaxation and heat radiation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a substrate is used in the chip-size package structure, then structural support is provided, but light extraction efficiency decreases and color degradation occurs
Solution Approach 1:
The patent removes the substrate from the chip-size package structure to eliminate the cause of color degradation and improve light extraction efficiency. The semiconductor light-emitting element is mounted directly on the circuit board without a substrate layer, allowing light to be extracted more efficiently and uniformly.
2Strength
If a substrate is present in the device structure, then mechanical support is maintained, but metal migration and contamination risks increase
Solution Approach 1:
The substrate is removed from the device structure to eliminate the source of metal migration and contamination. The semiconductor light-emitting element is directly mounted on the circuit board, preventing metal ions from the substrate from migrating into the light-emitting layer and causing contamination.
3Reliability
If the device is designed without a substrate, then light extraction and reliability are improved, but structural support and stress management become challenging
Solution Approach 1:
The circuit board serves multiple functions: it provides mechanical support for the device, acts as a heat dissipation path, and serves as the mounting surface for the semiconductor light-emitting element. This multi-functional design compensates for the removed substrate's structural role while maintaining reliability.
Solution Approach 2:
The patent changes the mounting orientation from vertical (through a substrate) to horizontal (directly on the circuit board surface). This dimensional change allows the circuit board to provide structural support in a different orientation, effectively compensating for the removed substrate.
4Ease of operation
If a complex wiring structure is implemented on the insulating film, then electrical connectivity is achieved, but device complexity increases
Solution Approach 1:
The patent combines the wiring structure with the insulating film by forming wiring portions directly on the insulating film's surface. This integration reduces the number of separate components and simplifies the overall device structure while maintaining electrical connectivity.
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 enhances light output, reduces color degradation, and improves reliability by eliminating substrate-related issues and preventing metal contamination, while allowing for efficient heat dissipation and stress relaxation, resulting in a compact, high-reliability semiconductor light-emitting device.
Implementation Method 1
a light-emitting layer 13 between the first and second surfaces
Implementation Method 2
A phosphor layer 30 is provided on the first surface 15a of the semiconductor layer 15
Implementation Method 3
A resin layer 25 is provided on the second surface 15b of the semiconductor layer 15
Data Source
AI summary
According to one embodiment, a semiconductor light-emitting device includes a first electrode and a second electrode provided on the same side of a semiconductor layer. A first insulating film covers the first electrode and the second electrode. Openings in the first insulating film expose portions of the first electrode and the second electrode. Wiring portions are respectively provided on the first insulating film and in the openings in the first insulating films. A first wiring portion is connected to the first electrode and a second wiring portion is connected to the second electrode. A second insulating film is provided between a first wiring portion and a second wiring portion, with a portion of the second insulating film being provided in a gap between the first insulating film and the first wiring portion.