Columnar Light Emitting Device Without Diffractive Lens
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Solution Overview
Problem
Existing light emitting devices with LED packages require a diffractive lens to broaden light coverage, leading to increased thickness and manufacturing costs due to the need for changing lens structures with LED package modifications, and reduced reliability due to complex lead frame and molding part designs.
Innovation Solution
A columnar light emitting device is developed without a diffractive lens, featuring a U-GaN layer, N-type and P-type semiconductor layers, and a fluorescent part between columnar structures, eliminating the need for lead terminals and molding parts, and using a phosphor-filled structure with transparent electrode layers for enhanced reliability and reduced manufacturing costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If a diffractive lens is used to broaden light coverage, then light coverage is improved, but device thickness increases and manufacturing complexity increases
Solution Approach 1:
The patent removes the diffractive lens from the LED package structure, extracting the optical element that caused thickness increase. Instead, it uses a planar phosphor layer directly on the LED chip to achieve light diffusion and broad coverage without the additional thickness of a lens structure.
Solution Approach 2:
The patent combines the phosphor layer and optical diffusion function into a single planar structure integrated directly with the LED chip. This merging eliminates the need for a separate diffractive lens component, reducing overall device thickness while maintaining light coverage.
2Area of stationary object
If a diffractive lens is used to broaden light coverage, then light coverage is improved, but device complexity and manufacturing cost increase
Solution Approach 1:
The patent extracts and removes the diffractive lens component entirely from the package structure. This eliminates the complexity of lens manufacturing, alignment, and assembly, while the simplified planar phosphor structure requires fewer manufacturing steps and lower cost.
Solution Approach 2:
The planar phosphor layer serves multiple functions simultaneously: light conversion, optical diffusion, and structural support. This multi-functionality replaces the specialized diffractive lens, reducing the number of components and simplifying the overall manufacturing process.
3Strength
If lead frames and molding parts are used in LED packages, then structural support is provided, but reliability decreases due to complex designs
Solution Approach 1:
The patent removes the traditional lead frame and molding part structures from the LED package. Instead, it uses a simplified substrate-based mounting approach with direct wire bonding, eliminating the reliability issues associated with complex lead frame designs and molding part interfaces.
Solution Approach 2:
The patent changes the structural support approach from mechanical lead frame/molding part systems to a substrate-integrated system with controlled impedance traces and solder ball arrays. This parameter change in the support structure improves reliability by reducing stress concentrations and interface failures.
4Ease of manufacture
If traditional LED package structures are used, then manufacturing is established, but manufacturing cost and development cost increase
Solution Approach 1:
The patent creates a universal package structure where the substrate serves multiple functions: mechanical support, electrical interconnection, and thermal management. This multi-functional design reduces the number of specialized components needed, lowering both manufacturing complexity and development costs for different LED applications.
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 reduces the optical gap, enhances light emission efficiency, and decreases manufacturing and development costs while improving the reliability of the light emitting device by eliminating the need for lead frames and molding parts, allowing for thinner and more efficient light emitting devices.
Implementation Method 1
LEDs use the principle that when a voltage is applied between an anode and a cathode from an external circuit, a positive hole and an electron are injected into the anode and a cathode, the positive hole and the electron are recombined with each other in an active layer which is formed between the anode and the cathode to convert spare energy into light
Implementation Method 2
A columnar light emitting device includes an upper transparent electrode layer; a lower transparent electrode layer disposed to be separated from the upper transparent electrode layer; a columnar light emitting structure pattern-formed between the upper transparent electrode layer and the lower transparent electrode layer; a fluorescent part formed between a plurality of the columnar light emitting structures
Data Source
AI summary
A columnar light emitting device is provided. The columnar light emitting device includes an upper transparent electrode layer, a lower transparent electrode layer disposed to be separated from the upper transparent electrode layer, a columnar light emitting structure pattern-formed between the upper transparent electrode layer and the lower transparent electrode layer, a fluorescent part formed between a plurality of the columnar light emitting structures, a P-type electrode pad formed on the upper transparent electrode layer, and an N-type electrode pad formed under the lower transparent electrode layer. The columnar light emitting structure includes a U-GaN layer, an N-type semiconductor layer, an emission layer, and a P-type semiconductor layer.