Polyamide Resin Composition for LED Reflecting Plates

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Solution Overview

Problem

Current polyamide resin compositions for reflecting plates in LEDs lack sufficient heat resistance, mechanical strength, and reflectivity, particularly during the reflow soldering process, and exhibit poor adhesion with sealing resins, leading to reduced reflectivity and productivity issues.

Innovation Solution

A polyamide resin composition comprising 30-80% polyamide resin, 10-60% inorganic filler, 5-50% white pigment, 0.05-2 parts by weight photostabilizer, and 0.05-3 parts by weight inorganic fine particles, which enhances heat resistance, mechanical strength, and reflectivity while minimizing reflectivity reduction and adhesion issues.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If liquid crystal polymers (LCPs) are used to achieve excellent heat resistance and light resistance, then heat resistance is improved, but adhesion with sealing resin deteriorates and reflectance is reduced

Engineering Contradiction:
Improveheat resistanceVSAvoidadhesion with sealing resin
Core Design Contradiction:
TemperatureVSReliability

Solution Approach 1:

The patent uses a composite material system consisting of polyamide resin as the base polymer, combined with specific inorganic fillers (glass beads, metal particles) and white pigments. This composite structure provides both the heat resistance needed for reflow soldering and the adhesion properties required for sealing resin bonding, while maintaining high reflectance through the white pigment content of 5-50 wt%.

Inventive Principle:
Principle #40Composite materials

2Strength

If aliphatic polyamides are used to achieve excellent strength and injection molding formability, then mechanical strength is improved, but heat resistance deteriorates

Engineering Contradiction:
Improvemechanical strengthVSAvoidheat resistance
Core Design Contradiction:
StrengthVSTemperature

Solution Approach 1:

The patent modifies the polyamide resin parameters by controlling the intrinsic viscosity within a specific range (0.3-0.9 dl/g) and adjusting the molecular weight distribution. This parameter optimization allows the polyamide to maintain excellent injection molding formability and mechanical strength while achieving sufficient heat resistance for LED reflow soldering processes.

Inventive Principle:
Principle #35Parameter changes

3Strength

If inorganic fillers are added to improve strength, then mechanical strength is improved, but reflectivity is reduced

Engineering Contradiction:
Improvemechanical strengthVSAvoidreflectivity
Core Design Contradiction:
StrengthVSManufacturing precision

Solution Approach 1:

The patent applies local quality by using spherical glass beads with specific surface treatments that provide both mechanical reinforcement and light scattering properties. The glass beads are surface-modified to enhance light reflection while maintaining structural strength, and are distributed uniformly throughout the polyamide matrix to locally improve both strength and reflectivity simultaneously.

Inventive Principle:
Principle #3Local quality

Data Source

PatentUS9403980B2Polyamide composition having surface reflectance and heat resistance
Publication Date: 2016.08.02 LOTTE ADVANCED MATERIALS CO LTD

AI summary

A polyamide resin composition includes (A) a polyamide resin in an amount of about 30 to about 80% by weight, (B) inorganic filler in an amount of about 10 to about 60% by weight, (C) white pigment in an amount of about 5 to about 50% by weight; and (D) photostabilizer in an amount of about 0.05 to about 2 parts by weight and (E) inorganic fine particles in an amount of about 0.05 to about 3 parts by weight, wherein each of (D) and (E) is based on about 100 parts by weight of the polyamide resin (A). The polyamide resin composition can have good light reflectance and yellowing resistance.