Light Emitting Device Package Pad Layout for Short-Circuit Prevention

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional light emitting device packages face reliability issues due to potential electrical connections through cracks in the insulation layer, leading to short-circuits and reduced heat radiation, especially when the second pad overlaps the first insulation layer in the through-holes.

Innovation Solution

The light emitting device package design features a second pad that does not overlap the first insulation layer in the through-holes, ensuring electrical spacing and preventing short-circuits, with the second pad located near the through-holes rather than embedded within them, and using a reflective second electrode to enhance light extraction efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the second pad is positioned to overlap the first insulation layer in the through-holes, then electrical connection is achieved, but short-circuits occur through cracks in the insulation layer

Engineering Contradiction:

Improveelectrical connection reliabilityVSAvoidshort-circuit risk

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent introduces a reflective second electrode as an intermediary component between the second pad and the first insulation layer. This reflective electrode serves multiple functions: it maintains electrical connection while preventing direct contact between the second pad and cracked insulation layer, thereby eliminating the short-circuit pathway while preserving electrical conductivity.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent positions the second pad laterally adjacent to the through-holes rather than directly overlapping them in the vertical dimension. This dimensional repositioning eliminates the short-circuit risk through cracks while maintaining electrical connection through the reflective second electrode that extends into the through-holes, effectively solving the contradiction by changing the spatial arrangement.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Reliability

If the second pad is positioned to overlap the first insulation layer, then electrical connection is achieved, but heat radiation is reduced

Engineering Contradiction:

Improveelectrical connectionVSAvoidheat radiation efficiency

Core Design Contradiction:

ReliabilityVSTemperature

Solution Approach 1:

The reflective second electrode acts as an intermediary that separates the heat generation zone (second pad) from the heat dissipation zone (first insulation layer and substrate). This intermediary structure allows electrical connection while improving thermal management by directing heat away from critical areas through the reflective surface, thereby enhancing heat radiation efficiency without compromising electrical connection.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Object-affected harmful factors

If the second pad is located away from the through-holes, then short-circuits are prevented, but electrical connection efficiency is reduced

Engineering Contradiction:

Improveshort-circuit preventionVSAvoidelectrical connection efficiency

Core Design Contradiction:

Object-affected harmful factorsVSReliability

Solution Approach 1:

The patent merges the functions of the second pad and the reflective second electrode into an integrated structure. The second pad is positioned laterally away from the through-holes to prevent short-circuits, while the reflective second electrode extends into the through-holes to maintain electrical connection. This merging of functions allows the system to achieve both short-circuit prevention and efficient electrical connection simultaneously.

Inventive Principle:

Principle #5Merging (Combining)

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 the reliability of the light emitting device package by preventing short-circuits and improving heat radiation, while maintaining efficient light extraction and transmission through the use of a reflective second electrode.

Implementation Method 1

using a reflective second electrode to enhance light extraction efficiency

Methodology Applied

Scientific EffectReflection: Reflection

Data Source

PatentUS10475978B2Light emitting device package having improved reliability, and lighting apparatus including the package

Publication Date: 2019.11.12 BOE HC SEMITEK LTD (HENGQIN)

AI summary

Embodiments provide a light emitting device package including a substrate, a light emitting structure disposed under the substrate and including a first conductive semiconductor layer, an active layer, and a second conductive semiconductor layer, first and second electrodes connected to the first and second conductive semiconductor layers, a first pad connected to the first electrodes in first-first through-holes penetrating the second conductive semiconductor layer and the active layer, and a first insulation layer disposed between the first pad and the second conductive semiconductor layer and between the first pad and the active layer to cover the first electrodes in a first-second through-hole, and a second pad connected to the second electrode through a second through-hole penetrating the first insulation layer and electrically spaced apart from the first pad. The second pad does not overlap the first insulation layer in the first-second through-hole in a thickness direction of the light emitting structure.