LED Package Molding with Release Paper Mediator
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Solution Overview
Problem
Existing methods for fabricating LED packages are cumbersome and difficult to adjust for varying viewing angles, leading to issues like hot spots and reduced light efficiency due to undesired shapes of the encapsulation member.
Innovation Solution
A method involving the use of a diffuser mixed into a transparent resin for forming the housing, allowing adjustment of the viewing angle through controlled mixing ratios, and employing transfer molding to form both the encapsulation member and housing, enabling easier design and fabrication of LED packages with desired light viewing angles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a liquefied resin is injected into the cavity of the ejection-molded housing in a dotting manner to form the encapsulation member, then the encapsulation member is formed, but it acquires an undesired upwardly convex shape due to surface tension which deteriorates optical performance and causes hot spot phenomenon
Solution Approach 1:
A release paper is introduced as an intermediary between the mold cavity and the resin. The release paper prevents direct contact between the resin and the mold cavity wall, eliminating the surface tension effect that causes the convex shape. The resin is injected between the release paper and the cavity, allowing controlled formation of a flat or desired shape encapsulation member without hot spot issues.
2Adaptability or versatility
If the viewing angle of the LED package is adjusted by changing the shape of the housing reflection surface, then the light collection is optimized, but the design and fabrication become cumbersome and complicated due to the large difference between housing molding and encapsulation member molding methods
Solution Approach 1:
The housing and encapsulation member are formed in the same mold cavity using the same injection molding process. The release paper enables the encapsulation member to be formed in the housing cavity without requiring a separate molding process. This unified approach allows viewing angle adjustment through housing shape design while simplifying the fabrication process into a single consecutive operation.
3Productivity
If the amount of liquefied resin injected into the cavity is reduced, then injection time is reduced, but an undesired concave shape is generated which decreases light emitting efficiency
Solution Approach 1:
The release paper acts as a mediator that decouples the resin injection process from the mold cavity wall. This allows the resin to be injected rapidly without adhering to the cavity wall, preventing concave shape formation even with reduced injection amounts. The release paper ensures uniform shape control regardless of injection speed or resin volume.
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
This approach enhances the control over light viewing angles, reduces hot spots, and improves light emitting efficiency by allowing for the formation of desired shapes, while also simplifying the fabrication process and increasing productivity.
Implementation Method 1
forming a housing which is light transmittable for supporting the base; wherein the step of forming the housing is performed using a molding material in which a diffuser is mixed into a transparent resin
Implementation Method 2
the step of forming the encapsulation member comprises the step of molding the encapsulation member using a mold
Implementation Method 3
the encapsulation member is configured to have an undesired, upwardly convex shape due to the surface tension exerted on the liquefied resin
Data Source
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AI summary
An LED package is disclosed herein. The disclosed LED package comprises a base having an LED chip mounted thereon, an encapsulation member formed by a light-transmittable resin to encapsulate the LED chip, and a housing formed to expose a top portion of the encapsulation member and to encompass a side surface of the encapsulation member, wherein the encapsulation member is formed by a transfer molding process using a mold to have a predetermined shape. Further, the housing may be light-transmittable.