Submount-Free LED Components with Reflective Layer

Solution Overview

Problem

The use of submounts in LED components adds processing complexity and cost, and can impact the reliability of the LED component, necessitating a submount-free solution for efficient mounting on printed circuit boards.

Innovation Solution

The implementation of a submount-free LED component design where a reflective layer extends between the LED die and contact, and along the die sidewall, with wire bonds connecting the LED die to discrete contacts, allowing for direct mounting on a board without a submount, and incorporating luminophoric material and optically transparent structures for enhanced performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a submount is used in LED component design, then the LED die can be supported and electrical connections can be made, but the processing complexity and cost increase, and reliability is impacted

Engineering Contradiction:

ImproveLED component reliabilityVSAvoidprocessing complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent removes the submount from the LED component structure, extracting the problematic intermediate element that caused processing complexity and reliability issues. The LED die is mounted directly to the printed circuit board, eliminating the submount layer entirely while maintaining all necessary electrical and mechanical functions through direct bonding techniques.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent merges the functions previously separated by the submount into a direct connection between the LED die and printed circuit board. The electrical connections, mechanical support, and thermal management functions are combined into a single direct mounting interface, reducing the number of components and processing steps required.

Inventive Principle:

Principle #5Merging (Combining)

2Reliability

If a submount is used in LED component design, then the LED die can be supported and electrical connections can be made, but the manufacturing cost increases

Engineering Contradiction:

ImproveLED component reliabilityVSAvoidmanufacturing cost

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent removes the submount from the LED component structure, extracting the problematic intermediate element that caused processing complexity and reliability issues. The LED die is mounted directly to the printed circuit board, eliminating the submount layer entirely while maintaining all necessary electrical and mechanical functions through direct bonding techniques.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent merges the functions previously separated by the submount into a direct connection between the LED die and printed circuit board. The electrical connections, mechanical support, and thermal management functions are combined into a single direct mounting interface, reducing the number of components and processing steps required.

Inventive Principle:

Principle #5Merging (Combining)

3Illumination intensity

If a reflective layer extends along the die sidewall, then light output is enhanced, but the manufacturing precision requirements increase

Engineering Contradiction:

Improvelight outputVSAvoidreflective layer precision

Core Design Contradiction:

Illumination intensityVSManufacturing precision

Solution Approach 1:

The patent applies the reflective layer selectively to specific regions: on the inner face adjacent to the LED die and extending along the die sidewall, but with controlled boundaries. This localized application provides enhanced light output in critical areas while limiting the total area requiring high-precision manufacturing, thereby balancing performance with manufacturability.

Inventive Principle:

Principle #3Local quality

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 simplifies the manufacturing process, reduces costs, and enhances the reliability and brightness of LED components by eliminating the need for submounts, while providing improved thermal management and light output through the use of white paint and phosphor layers.

Implementation Method 1

A reflective layer is provided on the inner face that extends to the die sidewall and also extends along the die sidewall

Methodology Applied

Scientific EffectReflection: Reflection

Implementation Method 2

a layer comprising luminophoric material, such as phosphor, is provided on the first face

Methodology Applied

Scientific EffectPhosphorescence: Phosphorescence

Data Source

PatentUS9214607B1Wire bonded light emitting diode (LED) components including reflective layer

Publication Date: 2015.12.15 CREELED INC

AI summary

A Light Emitting Diode (LED) component includes an LED die having first and second opposing faces and a sidewall. A contact is provided that is spaced apart from the LED die. The contact includes an inner face adjacent the first face and an outer face adjacent the second face. The contact may be a portion of a lead frame or a discrete contact slug. A wire bond extends between the first face and the inner face. A reflective layer is provided on the inner face that extends to the sidewall and also extends along the sidewall. The reflective layer may include white paint. Related fabrication methods are also described.