LED Package with Recessed Reflective Film for Light Extraction
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Solution Overview
Problem
Existing light emitting diode (LED) packages face challenges in achieving high light extraction efficiency and compact design for thinner backlight applications, particularly in liquid crystal display devices, due to light leakage and structural integrity issues.
Innovation Solution
A cup-shaped resin package with a reflective film integrated into recessed areas of the side walls, featuring a 3D shape with varying thicknesses and orientations, enhances light reflection and reduces leakage by positioning the reflective film internally, while maintaining structural strength through strategic protrusions and material distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the package height is reduced for thinner backlight applications, then the compactness is improved, but light extraction efficiency deteriorates due to light leakage
Solution Approach 1:
The patent applies local quality by providing reflective films only on specific surfaces (side walls and/or bottom surface) rather than uniformly across all surfaces. This localized reflection strategy addresses light leakage in the reduced-height package while maintaining compact dimensions, as the reflective films are selectively positioned where light escape occurs most prominently.
Solution Approach 2:
The patent uses composite materials by combining transparent resin material with reflective films (metal or dielectric layers) to create a hybrid structure. The transparent resin provides structural integrity and light transmission, while the reflective films compensate for light leakage caused by the reduced package height, achieving both compactness and improved light extraction efficiency.
2Loss of energy
If reflective films are added to improve light extraction efficiency, then light leakage is reduced, but device complexity increases
Solution Approach 1:
The patent merges the reflective film formation with the package manufacturing process itself, integrating the reflection function into the base package structure rather than adding separate components. The reflective films are formed directly on the side walls and/or bottom surface during molding, combining structural formation with optical function enhancement in a single integrated process.
Solution Approach 2:
The patent applies preliminary action by forming the reflective films on the side walls and bottom surface during the initial package molding process, before the light-emitting element is mounted. This preliminary formation of reflective surfaces ensures optimal light extraction from the outset and simplifies subsequent assembly steps.
3Ease of manufacture
If the package structure is simplified for easier manufacturing, then ease of manufacture is improved, but light extraction efficiency deteriorates
Solution Approach 1:
The patent combines multiple functions into the base package structure: the transparent resin component provides both structural support and light transmission, while integrated reflective films on the side walls and bottom surface provide light reflection. This merging of structural and optical functions achieves improved light extraction efficiency without requiring separate complex components or additional assembly steps.
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 high light extraction efficiency and compact design, minimizing light leakage and enhancing structural integrity, thus improving the performance of LED packages for thinner backlight applications.
Implementation Method 1
a reflective film, the resin component having a 3-D shape defined by an X axis, a Y axis that is perpendicular tai the X axis and a Z axis that is perpendicular to the X and axes
Data Source
AI summary
A method for manufacturing a package includes molding a precursor of a package including a cup-shaped resin component having a bottom surface and side walls, an opening opened at an upper part of the side walls, and a pair of leads exposed on the bottom surface. The side walls include a side wall that extends along the Y axis and the X axis and that has a first outer surface, and a side wall that extends along the Y axis and the Z axis. A thickness of the side wall extending along Y axis and the X axis is less than a thickness of the side wall extending along axis and the Z axis. The first outer surface has a recess which is recessed in the Z axis direction and arranged in a position corresponding to the opening. The method further includes forming a reflective film in the recess.