Light Emitting Device Package with Integrated Bi-Directional Zener Diode
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Nitride semiconductor light emitting devices are vulnerable to electrostatic discharge (ESD) and require effective surge current management, while also needing enhanced heat dissipation and luminance efficiency.
Innovation Solution
A light emitting device package is designed with a bi-directional Zener diode integrated into an undoped semiconductor substrate, featuring conductive vias and external electrodes to manage surge currents and ESD, along with a light-transmissive resin for improved heat dissipation and luminance, utilizing flip-chip bonding and a recess structure for efficient light extraction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional LED package structure is used, then the structure is simple, but the device is vulnerable to electrostatic discharge (ESD) and surge currents
Solution Approach 1:
The patent merges the ESD protection function directly into the semiconductor substrate by forming a bi-directional Zener diode region within the substrate itself. This integration combines the substrate's structural role with the ESD protection function, eliminating the need for separate protection components while enhancing reliability against electrostatic discharge and surge currents in both forward and reverse directions.
Solution Approach 2:
The semiconductor substrate is designed to serve multiple functions simultaneously: it acts as the mechanical support structure, the electrical connection medium through conductive vias, and the ESD protection element through the integrated bi-directional Zener diode region. This multi-functionality allows a single component to provide both structural integrity and surge current management.
2Volume of moving object
If the package size is reduced for compact devices, then portability improves, but heat dissipation efficiency deteriorates
Solution Approach 1:
The patent addresses heat dissipation in a compact package by utilizing the vertical dimension (depth) of the substrate. The bi-directional Zener diode region is formed within the substrate thickness, and heat can be dissipated through the substrate's depth to the heat sink or package casing, rather than relying solely on horizontal surface area. This three-dimensional heat management approach allows effective thermal control in small packages.
3Reliability
If a unidirectional Zener diode is used for ESD protection, then the protection is simpler, but surge currents in the forward direction are not blocked
Solution Approach 1:
The patent employs asymmetric doping concentrations within the bi-directional Zener diode structure to achieve different breakdown characteristics in forward and reverse directions. By creating regions with different doping levels, the structure provides appropriate protection for surge currents regardless of polarity, with each direction having optimized breakdown voltage characteristics suited to its operational requirements.
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
The solution effectively blocks ESD in both forward and reverse directions, enhances heat dissipation, and improves luminance by integrating a bi-directional Zener diode and using a light-transmissive resin, while simplifying the package structure and improving reliability.
Implementation Method 1
a bi-directional Zener diode formed by doping an impurity on the second surface of the undoped semiconductor substrate and having a Zener breakdown voltage in both directions
Implementation Method 2
a light-transmissive resin for improved heat dissipation and luminance
Implementation Method 3
first and second conductive vias penetrating the undoped semiconductor substrate such that they connect the first and second surfaces
Data Source
AI summary
A light emitting device package includes: an undoped semiconductor substrate having first and second surfaces opposed to each other; first and second conductive vias penetrating the undoped semiconductor substrate; a light emitting device mounted on one region of the first surface; a bi-directional Zener diode formed by doping an impurity on the second surface of the undoped semiconductor substrate and having a Zener breakdown voltage in both directions; and first and second external electrodes formed on the second surface of the undoped semiconductor substrate such that they connect the first and second conductive vias to both ends of the bi-directional Zener diode region, respectively.