LED Lead Structure for Heat Dissipation in Compact Resin Packages
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional semiconductor light emitting devices face challenges in size reduction and efficient heat dissipation due to the limited thermal conductivity of their substrates, which hinders the enhancement of brightness without increasing heat generation.
Innovation Solution
The semiconductor light emitting device incorporates a lead with a die bonding pad and an exposed surface for efficient heat dissipation, while maintaining a minimal size for proper mounting. This design includes a thin portion and a thick portion integral with the lead, where the thick portion is exposed outside the resin package, and the thin portion is covered by the resin package.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If the current to flow through the LED chip is increased to enhance brightness, then the brightness is improved, but the heat generated from the LED chip increases
Solution Approach 1:
The patent extracts the heat dissipation function from the substrate by introducing a dedicated lead structure with high thermal conductivity. The lead is specifically designed to conduct heat away from the LED chip to the resin package, separating the light emission function (LED chip) from the heat dissipation function (lead), thereby enabling brightness enhancement without proportional heat generation in the substrate.
Solution Approach 2:
The patent employs composite material strategy by combining materials with different thermal conductivity characteristics. The lead is made of material with high thermal conductivity to efficiently conduct heat, while the resin package provides thermal insulation and structural support. This composite approach creates an effective heat dissipation pathway that allows increased current flow through the LED chip without excessive heat accumulation.
2Temperature
If the substrate material is changed to improve thermal conductivity, then the heat dissipation is improved, but the device complexity increases
Solution Approach 1:
The lead structure serves multiple functions simultaneously: it provides electrical connection for current flow, acts as a heat dissipation pathway due to its high thermal conductivity, and maintains structural support for the LED chip. By making the lead multi-functional, the patent avoids the need for separate dedicated heat dissipation components, thereby improving heat dissipation without significantly increasing device complexity.
Solution Approach 2:
Instead of changing the substrate material to improve thermal conductivity (which would increase complexity), the patent inverts the approach by making the lead (a necessary component anyway) the primary heat dissipation element. The lead is designed with high thermal conductivity and direct thermal contact with the LED chip, reversing the conventional role where the substrate was expected to handle heat dissipation.
3Volume of moving object
If the device size is reduced, then the size reduction is achieved, but the heat dissipation efficiency decreases
Solution Approach 1:
The patent applies local quality principle by concentrating heat dissipation functionality in the lead region rather than distributing it throughout the entire device. The lead is specifically designed with high thermal conductivity and direct thermal contact with the LED chip, creating a localized efficient heat dissipation pathway. This allows the rest of the device to be miniaturized while maintaining effective heat dissipation through the specialized lead structure.
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 configuration allows for effective heat escape through the lead, enabling increased brightness and achieving size reduction of the semiconductor light emitting device while ensuring reliable mounting and light mixing.
Implementation Method 1
the heat from the semiconductor light source efficiently escapes through the lead
Data Source
AI summary
A semiconductor light emitting device includes a semiconductor light source, a resin package surrounding the semiconductor light source, and a lead fixed to the resin package. The lead is provided with a die bonding pad for bonding the semiconductor light source, and with an exposed surface opposite to the die bonding pad The exposed surface is surrounded by the resin package in the in-plane direction of the exposed surface.