LED Chip Scale Packaging with Free-Form Lens and Diffusion Structure
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Solution Overview
Problem
Existing light emitting diode (LED) packaging structures face challenges in achieving thin designs and maintaining optical accuracy due to manufacturing complexities and optical shifts during assembly, particularly with refractive lenses, which limit their application in direct type backlight modules.
Innovation Solution
A light emitting diode chip scale packaging structure incorporating a wavelength converting layer with phosphor powders, a diffusion structure with specific refractive index and particle size, and a free-form lens surface that follows a polynomial curve, enhancing light diffusion and minimizing air gaps to improve luminous efficiency and display effects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If a reflective lens is used to lead light toward the bottom surface, then the module can achieve a thinner design, but the manufacturing process requires high accuracy and has high technical difficulty
Solution Approach 1:
The patent introduces a diffusion structure as an intermediary component between the light emitting diode chip and the lens. This diffusion structure has a specific refractive index and contains particles that scatter light, acting as a mediator to redirect light paths without requiring precise alignment. The diffusion structure converts direct light into scattered light, which then passes through the lens to achieve the desired thin module design while reducing manufacturing complexity.
2Manufacturing precision
If a refractive lens is used to directly lead light to the imaging plane, then the manufacturing tolerance is larger, but it is very difficult to achieve a thin product due to physical threshold limitations
Solution Approach 1:
The patent segments the optical system into multiple functional components: a light emitting diode chip, a diffusion structure with specific refractive index and particle content, and a lens with specific curvature. This segmentation allows each component to perform its specific function independently, enabling the overall system to achieve thin design while maintaining manufacturing tolerance. The diffusion structure handles light scattering with relaxed tolerance, while the lens handles focal control.
Solution Approach 2:
The diffusion structure is composed of a transparent or translucent material containing particles with specific refractive indices different from the base material. This composite structure enables both light diffusion and controlled transmission, allowing the module to achieve thin design while maintaining adequate manufacturing tolerance. The particle-matrix composite provides the necessary optical properties that neither component could achieve alone.
3Reliability
If elements are disposed during assembly, then optical shifts occur due to accuracy problems, but maintaining high accuracy increases manufacturing complexity
Solution Approach 1:
The diffusion structure performs self-alignment and self-correction functions. Due to its light-scattering properties and specific refractive index, it automatically compensates for minor misalignments between the light emitting diode chip and the lens. The diffusion structure's optical properties ensure that light is scattered in a controlled manner regardless of slight positional variations, making the system self-correcting and reducing the need for high-precision assembly processes.
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 enhances light diffusion, increases light emitting angles, and reduces light loss, resulting in improved luminous efficiency and display effects while facilitating miniaturization and cost reduction in LED packaging.
Implementation Method 1
the wavelength converting layer includes phosphor powders
Implementation Method 2
a diffusion structure covers the light emitting diode chip and the wavelength converting layer
Implementation Method 3
the lens covers the diffusion structure
Data Source
AI summary
A light emitting diode chip scale packaging structure and a direct type backlight module are disclosed. The light emitting diode chip scale packaging structure includes a light emitting diode chip, a wavelength converting layer, a diffusion structure and a lens. The wavelength converting layer is disposed on the light emitting diode chip and directly contacting the light emitting diode chip, and the wavelength converting layer includes phosphor powders. The diffusion structure covers the light emitting diode chip and the wavelength converting layer, a ratio of a height of the diffusion structure to a width of the diffusion structure is 1:2 to 5:4, and the lens covers the diffusion structure. An outer surface of the lens is a free-form surface, and a material of the lens is different from a material of the diffusion structure.