Asymmetric Resin Package Gate Marking for LED Strength
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Solution Overview
Problem
The existing methods for manufacturing light emitting devices often result in resin packages with voids and reduced strength due to resin injection from opposing sides, causing stress and gas traps at weld lines, which weaken the package.
Innovation Solution
The method involves arranging inlet and outlet ports asymmetrically in the mold to control resin flow, forming gate marks on the resin package's outer side surfaces to prevent voids and stress concentration, and using a thermosetting resin like triazine derivative epoxy for enhanced strength and reflectivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If resin is injected from both opposing surfaces through inlet ports, then the resin fills the cavity completely, but stress and gas traps occur at weld lines reducing package strength
Solution Approach 1:
The patent applies asymmetry by providing only a single inlet port in one of the opposing mold surfaces instead of symmetric inlet ports in both surfaces. This asymmetric configuration causes the resin to flow from one direction only, preventing the formation of weld lines where resin flows from opposite directions would meet. The single inlet port is positioned to optimize resin flow through the cavity while avoiding gas traps and stress concentration points.
2Ease of manufacture
If inlet ports are arranged at opposing outer side surfaces, then resin injection is simplified, but weld lines form reducing manufacturing quality
Solution Approach 1:
The patent extracts or removes one of the two opposing inlet ports that would traditionally be provided in both mold surfaces. By providing the inlet port in only one surface and omitting it from the opposing surface, the design eliminates the problem of weld line formation while maintaining effective resin injection capability through the single remaining inlet port.
3Productivity
If resin flows from two opposite directions, then cavity filling is efficient, but gas traps occur creating voids
Solution Approach 1:
The asymmetric inlet port configuration ensures resin flows from a single direction rather than from two opposite directions simultaneously. This unidirectional flow pattern prevents gas traps from forming at the center of the cavity where opposing flows would meet and mix, thereby eliminating void formation while maintaining efficient cavity filling through optimized single-direction flow.
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 ensures a resin package with improved mechanical strength, reduced voids, and enhanced light reflectivity, leading to a high-quality light emitting device with increased durability and efficiency.
Implementation Method 1
a resin is injected from an inlet port into a space defined by an upper mold and a lower mold to form a resin molded body on the lead frame
Data Source
Figure 1~2a
Figure 2b~3
Figure 4a
AI summary
Disclosed is a high-quality light-emitting device including a resin package having a recessed portion, which is able to be easily and reliably manufactured while securing higher strength. The light emitting device includes a light emitting element 2, a resin package 10 defining a recessed portion 105 serving as a mounting region of the light emitting element 2, gate marks 5a, 5b each formed on an outer side surface of the resin package 10, and leads 20, 30 disposed on the bottom surface of the recessed portion 105 and electrically connected to the light emitting element 2. The light emitting element 2 is mounted on the lead 20. The gate marks include a first gate mark 5a formed on a first outer side surface 11a of the resin package 10 and a second gate mark 5b formed on an outer side surface which is different than the first outer side surface 11 a.