Light Emitting Device Package Lead Frame With Variable Thickness
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Solution Overview
Problem
Current light emitting device packages face challenges in securely coupling lead frames to the package body, leading to potential instability and reduced reliability in heat dissipation and electrical connectivity.
Innovation Solution
The design incorporates a lead frame structure with a thickness ratio of 4:3 to 3:1 between regions, featuring convex-concave patterns and protrusions/depressions to increase coupling strength and surface roughness, ensuring secure attachment to the package body and enhanced heat dissipation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the lead frame is made with uniform thickness, then the manufacturing process is simple, but the coupling strength to the package body is insufficient
Solution Approach 1:
The lead frame is designed with non-uniform thickness, featuring a first region with greater thickness and a second region with lesser thickness. This local variation in thickness provides enhanced coupling strength at the package body interface (first region) while maintaining manufacturing feasibility (second region), thereby resolving the contradiction between coupling strength and structural complexity.
Solution Approach 2:
The lead frame is segmented into distinct functional regions: a first region for coupling to the package body and a second region for electrical connection. This segmentation allows each region to be optimized for its specific function, with the first region providing mechanical anchoring and the second region providing electrical connectivity, thus improving overall coupling strength without excessive complexity.
2Stability of the object's composition
If the lead frame has smooth surface, then the manufacturing is easier, but the coupling stability to package body is reduced
Solution Approach 1:
The lead frame surface is designed with convex-concave patterns and roughness features instead of a smooth surface. These curved and irregular surface profiles increase the mechanical interlocking between the lead frame and package body, thereby enhancing coupling stability. The convex portions engage with the package body material while concave portions provide anchoring, improving stability without requiring complex manufacturing processes.
3Strength
If the lead frame thickness is increased throughout, then the coupling strength improves, but the heat dissipation efficiency decreases
Solution Approach 1:
The lead frame employs local quality variation in thickness: the first region has greater thickness to provide strong mechanical coupling to the package body, while the second region has reduced thickness to minimize thermal resistance and improve heat dissipation from the light emitting device. This localized thickness optimization simultaneously achieves both strong coupling and efficient heat dissipation.
Solution Approach 2:
The solution moves from a uniform one-dimensional thickness parameter to a two-dimensional thickness distribution across the lead frame surface. By varying thickness in different spatial locations (first region vs. second region), the design optimizes both mechanical coupling strength and thermal performance without requiring overall thickness increase throughout the entire lead frame.
Data Source
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AI summary
A light emitting device package is disclosed. The light emitting device package includes a body (20), first (31) and second (32) lead frames disposed on the body, and a light emitting device (10) connected to the first and second lead frames, wherein at least one of the first and second lead frames includes first and second regions having different thicknesses.