Semiconductor Light-Emitting Device With Phosphor Resin And Sheet
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Solution Overview
Problem
Existing semiconductor light-emitting devices face challenges in achieving high total luminous flux while maintaining a compact size and easy production, with difficulties in managing light emission color and requiring complex equipment for substrate removal.
Innovation Solution
A semiconductor light-emitting device with a transparent insulating substrate and a semiconductor layer, where the side faces are covered with a thin phosphor resin and the upper surface is bonded with a phosphor sheet matching the outer shape, allowing for batch production and reduced size, and enabling easy management of light emission color.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If the transparent insulating substrate is removed to allow light emission only in the upward direction, then the device achieves compact chip size packaging, but the production process becomes complex requiring large-scale laser equipment
Solution Approach 1:
The patent extracts only the necessary function of the transparent insulating substrate (providing a base for the semiconductor layer) while removing the substrate itself. The semiconductor layer is transferred to a temporary substrate, processed, and then mounted on a leadframe, eliminating the need for large-scale laser equipment while achieving compact device size.
Solution Approach 2:
The production process is segmented into distinct stages: forming the semiconductor layer on a temporary substrate, processing the semiconductor layer, transferring it to a leadframe, and finally packaging. This segmentation allows each stage to be performed with appropriate equipment, avoiding the need for complex large-scale laser equipment while achieving compact device size.
2Area of stationary object
If the phosphor layer is formed on the LED device at the wafer level, then the device achieves compact size, but it becomes difficult to manage emission color variations among individual LED dies
Solution Approach 1:
The patent applies different phosphor layers to different individual LED dies based on their specific emission characteristics. Each LED die can have a customized phosphor layer composition and thickness, allowing precise control of emission color for each device while maintaining compact wafer-level packaging size.
Solution Approach 2:
The semiconductor layer is processed and characterized on the wafer level before dicing, allowing measurement of emission characteristics. Based on these measurements, phosphor layers are then applied to each individual die to correct and optimize emission color, achieving precise color management in compact devices.
3Device complexity
If a white reflective member is used to cover side faces, then the device structure is simplified, but the total luminous flux is reduced compared to using phosphor resin
Solution Approach 1:
The patent changes the material parameter of the side-face coating from white reflective material to phosphor resin. This parameter change allows the side faces to contribute to light emission through wavelength conversion, increasing total luminous flux while maintaining relatively simple device structure.
Solution Approach 2:
The phosphor resin serves multiple functions: it acts as a reflective layer to redirect light, as a wavelength converter to change light color, and as a protective coating. This multi-functionality increases total luminous flux without significantly increasing device structure complexity.
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 solution achieves a higher total luminous flux and compact size, simplifying production while allowing for precise control over light emission color, outperforming devices with white reflective layers.
Implementation Method 1
a phosphor resin which covers a side face of the transparent insulating substrate, and which wavelength-converts a portion of light emitted from the semiconductor light-emitting element
Implementation Method 2
a phosphor sheet which covers an upper surface of the phosphor resin and is bonded to the transparent insulating substrate
Data Source
AI summary
An object of the present invention is to provide an LED device that can achieve a large total luminance flux while also achieving a structure, using a phosphor sheet, that is compact in size and easy to produce and whose color emission is easy to manage, and a method for producing such an LED device. A semiconductor light-emitting device including a semiconductor light-emitting element which includes a transparent insulating substrate and a semiconductor layer formed on a lower surface of the transparent insulating substrate, a phosphor resin which covers a side face of the transparent insulating substrate, and which wavelength-converts a portion of light emitted from the semiconductor light-emitting element, and a phosphor sheet which covers an upper surface of the phosphor resin and is bonded to the transparent insulating substrate, wherein the phosphor sheet has a top plan shape that is identical with an outer peripheral shape of the phosphor resin, and the top plan shape of the phosphor sheet defines an overall outer plan shape of the device.