LED Package Die Pad Thermal Dissipation via Folded Lead Insulation
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Solution Overview
Problem
Conventional LED packages face challenges in direct surface-mounting to metal heat sinks due to short-circuit risks and inefficient thermal dissipation, leading to increased manufacturing costs and reduced reliability.
Innovation Solution
A semiconductor lead frame package design featuring a die pad exposed to the bottom surface, allowing direct thermal attachment to a heat sink, with a folded lead structure that reduces short-circuit risks by recessing the connecting portion within the insulator body, enabling efficient heat dissipation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional LED package uses exposed electrodes on the bottom surface, then electrical connection is achieved, but direct surface-mounting to metal heat sink causes short circuit
Solution Approach 1:
The patent introduces an insulator body as an intermediary component that encapsulates the lead frame. This insulator body provides electrical isolation between the exposed electrodes and the metal heat sink, allowing direct surface-mounting without short circuit risk while maintaining reliable electrical connection through the insulator material.
2Reliability
If a printed circuit board is used as buffer between LED package and heat sink, then short circuit is prevented, but manufacturing cost significantly increases
Solution Approach 1:
The patent merges the functions of the insulator body and the buffer layer into a single integrated component. The insulator body simultaneously provides electrical isolation, mechanical support, and thermal management functions, eliminating the need for separate printed circuit board buffer layers and reducing manufacturing complexity and cost.
3Temperature
If thermal vias or metal inserts are added to circuit board, then thermal impedance between LED package and heat sink is reduced, but manufacturing cost increases further
Solution Approach 1:
The patent extracts the thermal management function from the circuit board and integrates it directly into the LED package structure through the insulator body. The insulator body is designed with thermal conductivity properties that enable efficient heat transfer from the LED chip to the heat sink without requiring additional thermal via holes or metal inserts in the circuit board.
4Reliability
If COB package uses MCPCB with insulating layer, then direct surface-mounting to heat sink is enabled, but heat transmission is significantly hindered
Solution Approach 1:
The patent employs composite material design for the insulator body that combines electrical insulation properties with enhanced thermal conductivity. This composite structure allows the insulator to simultaneously provide electrical isolation and efficient heat transmission pathways, overcoming the thermal barrier problem of conventional MCPCB insulating layers while maintaining direct mounting capability.
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 design enhances heat dissipation efficiency and reduces manufacturing costs by allowing direct contact between the die pad and heat sink, minimizing short-circuit risks and improving LED package reliability.
Implementation Method 1
the bottom surface of the die pad is exposed from a bottom surface of the insulator body... the exposed bottom surface of the die pad directly contacts a heat sink... heat generated by the die can be dissipated to the air rapidly through the die pad and the heat sink
Data Source
AI summary
The present invention relates to a semiconductor lead frame package and LED package. The semiconductor lead frame package includes a die pad, a lead, a die and an insulator body. The lead is electrically isolated from the die pad. The die is disposed on the die pad and electrically connected to the lead. The insulator body partially encapsulates the die pad and the lead, and has a top surface and a bottom surface, wherein a part of the lead is folded onto the top surface of the insulator body.