LED Package Reinforcement and Sealing to Suppress Substrate Warping

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Solution Overview

Problem

Existing methods for manufacturing light emitting devices face challenges in suppressing warping due to thermal expansion differences between substrate and reinforcing materials, limiting material options and requiring additional processing steps.

Innovation Solution

A method involving a substrate with distinct regions for light emitting elements, a reinforcement member, and a sealing member with lower rigidity than the reinforcement member, where the reinforcement member and sealing member are integrated during curing to minimize warping, and the substrate and sealing member are cut to form individual devices.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If a plate shaped reinforcing material is joined to the substrate to suppress warping deformation, then the warping suppression is improved, but the material options are limited due to linear expansion differences and additional processing steps are required

Engineering Contradiction:

Improvewarping suppressionVSAvoidprocessing steps

Core Design Contradiction:

Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The sealing member is designed to simultaneously perform sealing and reinforcement functions. By forming the sealing member with higher rigidity than conventional sealing materials, it integrates the reinforcement function into the sealing component, eliminating the need for separate reinforcing materials and reducing processing steps while maintaining warping suppression capability

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The sealing member is designed to serve multiple functions: sealing the light emitting elements, providing structural reinforcement to suppress substrate warping, and maintaining stability under thermal expansion. This multi-functional design eliminates the need for separate reinforcing materials and simplifies the overall device structure

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Stability of the object's composition

If a plate shaped reinforcing material is joined to the substrate to suppress warping deformation, then the warping suppression is improved, but extra man hours are required due to separate joining steps

Engineering Contradiction:

Improvewarping suppressionVSAvoidmanufacturing time

Core Design Contradiction:

Stability of the object's compositionVSLoss of time

Solution Approach 1:

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The sealing member is pre-formed with the necessary rigidity and structural characteristics to provide reinforcement before assembly. This preliminary preparation allows the sealing member to immediately perform both sealing and reinforcement functions upon installation, eliminating the need for subsequent joining operations and reducing manufacturing time

Inventive Principle:

Principle #10Preliminary action

3Adaptability or versatility

If materials with different linear expansion coefficients are used for substrate and reinforcing material, then material versatility is improved, but warping is caused by expansion/contraction difference due to heat change

Engineering Contradiction:

Improvematerial optionsVSAvoidwarping

Core Design Contradiction:

Adaptability or versatilityVSStability of the object's composition

Solution Approach 1:

The rigidity parameter of the sealing member is increased beyond conventional sealing materials. By making the sealing member significantly more rigid, it can accommodate and compensate for thermal expansion differences between the substrate and sealing member materials, allowing greater material versatility while preventing warping through the rigid structure's ability to maintain dimensional stability under thermal stress

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS11757062B2Method for manufacturing light emitting device using reinforcement member

Publication Date: 2023.09.12 NICHIA CORP

AI summary

A method for manufacturing a light emitting device includes: preparing a substrate having a first region and a second region surrounding the first region; mounting a plurality of light emitting elements in the first region; mounting a reinforcement member on the second region; forming and curing a sealing member in contact with the reinforcement member and with the light emitting elements, the sealing member having a lower rigidity than the reinforcement member; and cutting the substrate, the reinforcement member, and the sealing member to separate into individual light emitting devices each including one or more of the light emitting elements.