LED Bond-Package Refining via Continuous Roll-Shaping and UV Curing

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Solution Overview

Problem

Existing LED packaging methods using organic silicone resin photoconverters face issues such as pores, unequal thickness, and low production efficiency, leading to reduced luminous efficacy and yield, particularly due to thermal overstress and complex processes.

Innovation Solution

A continuous process method involving roll-shaping of a microporous carrier sheet, refining of a semi-cured photoconversion sheet, preparation of a flip chip LED array, roll-bonding, curing, and cutting, which integrates shaping, refining, and bonding procedures to eliminate flaws and ensure uniformity, using a refining equipment system with negative pressure suction and light irradiation to produce high-quality LED packages.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If conventional LED packaging methods using organic silicone resin photoconverters are used, then the process is simple, but pores and unequal thickness occur leading to reduced luminous efficacy

Engineering Contradiction:

Improveprocess simplicityVSAvoidphotoconverter uniformity

Core Design Contradiction:

Ease of manufactureVSManufacturing precision

Solution Approach 1:

The photoconverter slurry is applied to the carrier sheet before LED mounting, allowing the material to be pre-distributed uniformly across the entire array. This preliminary action ensures consistent thickness and eliminates pores before the bonding process, resolving the contradiction between simple manufacturing and high precision.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

A microporous carrier sheet is introduced as an intermediary substrate to support the photoconverter slurry during processing. The carrier sheet enables uniform material distribution and facilitates subsequent refining operations, achieving high precision photoconverter layers while maintaining process simplicity.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Ease of manufacture

If thermal curing is used to cure the photoconverter, then the process is straightforward, but thermal overstress reduces yield and luminous efficacy

Engineering Contradiction:

Improvecuring process simplicityVSAvoidLED yield

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

Thermal curing is replaced with UV light irradiation for curing the photoconverter. This substitution eliminates thermal overstress that damages LED chips, significantly improving yield and luminous efficacy while maintaining ease of manufacture through a straightforward UV curing process.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The curing process utilizes photopolymerization phase transition where UV light initiates chemical bonding in the photoconverter slurry. This phase transition occurs at room temperature without thermal stress, preserving LED chip integrity while achieving complete curing.

Inventive Principle:

Principle #36Phase transitions

3Manufacturing precision

If complex refining processes are implemented to eliminate pores and ensure uniformity, then manufacturing precision improves, but production efficiency decreases

Engineering Contradiction:

Improvephotoconverter uniformityVSAvoidproduction efficiency

Core Design Contradiction:

Manufacturing precisionVSProductivity

Solution Approach 1:

Multiple refining operations (negative pressure suction, magnetic vibration, and light irradiation) are merged into a single integrated refining device that processes the photoconverter slurry in one continuous pass. This combination achieves high manufacturing precision without sacrificing production efficiency, as all refining actions occur simultaneously during one operation.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The refining process is designed as a continuous operation where the carrier sheet with photoconverter slurry passes through the refining device without interruption. Negative pressure suction, magnetic vibration, and UV irradiation occur continuously along the production line, maintaining both high precision and productivity.

Inventive Principle:

Principle #20Continuity of useful action

4Strength

If adhesive layers with phosphorous powder are used, then bonding is achieved, but luminous efficiency and color consistency deteriorate

Engineering Contradiction:

Improvebonding strengthVSAvoidcolor consistency

Core Design Contradiction:

StrengthVSManufacturing precision

Solution Approach 1:

The photoconverter slurry is applied locally to each LED chip position on the carrier sheet with precise thickness control. This local quality approach ensures uniform phosphorous powder distribution and consistent optical properties across all LEDs, achieving both bonding strength and color consistency without requiring separate adhesive layers.

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 method enhances production efficiency, improves brightness and color uniformity, and significantly increases yield by eliminating pores and crests, ensuring consistent specifications and dimensions, thus addressing the limitations of conventional processes.

Implementation Method 1

conveying the shaped microporous carrier sheet to a planar conveyor A with a recess array to continuously convey the sheet forward, and allocating mixed slurry containing a photoconversion material and organic silicone resin to the shaped microporous carrier sheet by using a doser, to form a mixed slurry layer with a fixed thickness; then continuously conveying the sheet forward to enter a refining device for negative pressure suction and light irradiation

Methodology Applied

Scientific EffectNegative pressure suction: Suction

Implementation Method 2

Methodology Applied

Scientific EffectPhotopolymerization: Photopolymerisation

Data Source

PatentEP3300126B1Process method for refining photoconverter to bond-package LED and refinement equipment system

Publication Date: 2019.05.22 JIANGSU CHERRITY OPTRONICS CO LTD

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AI summary

Provided are a process method for bond-packaging an LED using a refined photoconverter, and a refining equipment system. The process method includes the following continuous process flow: roll-shaping of a special-shaped microporous carrier sheet, refining of a semi-cured photoconversion sheet, preparation of a flip chip LED array sheet, forming of LED package elements by roll-bonding, curing of the LED package elements, and cutting of the LED package elements. The present invention has a significant advantage of a refined photoconverter, and especially can meet a requirement of a continuous process flow of bond-packaging an LED using an organic silicone resin photoconverter, so as to enhance the production efficiency and yield of LED packages in industrialized batch production.