LED Resin Package Notch Structure for Stronger Lead Adhesion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for manufacturing light emitting devices using thermoplastic resins face issues such as poor adhesion between the lead frame and the resin, difficulty in molding complex shapes, and significant light deterioration over time.
Innovation Solution
A method involving the use of a thermosetting resin with a light reflecting material, where a lead frame with notch parts is sandwiched by molds and the thermosetting resin is transfer-molded to form a resin-molded body, improving adhesion and allowing for the production of multiple light emitting devices simultaneously.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If thermoplastic resin is used for the resin-molded body, then the manufacturing process is simple, but the adhesion with the lead frame is poor and light deterioration occurs
Solution Approach 1:
The patent changes the fundamental parameter of resin type from thermoplastic to thermosetting resin. This parameter change fundamentally improves adhesion to the lead frame while maintaining manufacturing feasibility through transfer-molding processes, resolving the contradiction between ease of manufacture and reliability.
Solution Approach 2:
The patent employs composite materials by combining thermosetting resin with light-reflecting materials (such as titanium dioxide or aluminum powder) and potentially filler materials. This composite approach enhances both the adhesion properties and optical performance while maintaining structural integrity, addressing the reliability concerns.
2Reliability
If thermosetting resin is used for the resin-molded body, then the adhesion with the lead frame improves, but the resin fluidity is lower making complex shape molding difficult
Solution Approach 1:
The patent introduces a mold as an intermediary tool that enables the thermosetting resin to achieve complex shapes. The mold cavity defines the final shape, allowing the resin to be formed into complex geometries despite its lower inherent fluidity, thus resolving the contradiction between improved adhesion and moldability.
Solution Approach 2:
The patent applies parameter changes by controlling temperature and pressure conditions during the transfer-molding process. By optimizing these parameters, the thermosetting resin achieves sufficient flow to fill complex mold cavities while maintaining its superior adhesion properties, resolving the contradiction between reliability and ease of manufacture.
3Productivity
If conventional transfer-molding method is used, then multiple light emitting devices can be manufactured simultaneously, but a great amount of resin in runner parts is discarded
Solution Approach 1:
The patent applies segmentation by designing the mold with separate cavities for multiple light emitting devices, allowing each device to be formed independently. This enables simultaneous production of multiple units while optimizing resin distribution to minimize waste in runner parts, resolving the contradiction between productivity and material loss.
Solution Approach 2:
The patent optimizes the transfer-molding parameters including injection pressure, temperature, and timing to minimize resin waste in runner parts while maintaining the ability to manufacture multiple devices simultaneously. By carefully controlling these parameters, the system achieves high productivity with reduced material loss.
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 adhesion between the lead frame and the thermosetting resin, improves manufacturing efficiency, reduces material waste, and provides light emitting devices with high optical reflectivity and durability.
Implementation Method 1
a resin-molded body 24 in the lead frame 21, and a light reflecting material 26
Data Source
AI summary
A light emitting device includes: a resin package including: a resin part, and a plurality of leads including a first lead and a second lead, wherein the resin package has a concave portion having a bottom face at which a part of an upper surface of the first lead and a part of an upper surface of the second lead are exposed from the resin part; a light emitting element mounted on the bottom face of the concave portion; and a sealing member covering the light emitting element in the concave portion. The plurality of leads comprise a plurality of notch parts including a first notch part on a first side corresponding to a first outer side surface of the resin package and a second notch part on a second side corresponding to a second outer side surface of the resin package.