Why Is High-Temperature Solder Paste the Top Choice for LED Chip Packaging? Unveiling the Secret to Its Stability

In LED chip packaging, high-temperature solder paste is the preferred choice due to its high melting point and reliable soldering performance. As a specialized manufacturer in the high-temperature solder paste field, Fitech provides highly stable solutions for LED packaging through optimized material formulations and process adaptability design. The following analysis details its product characteristics:

MIP Structure

I. High Melting Point Characteristics: Physical Foundation Ensuring Thermal Stability

Fitech high-temperature solder paste utilizes Sn-Cu-X (SnCu) and SnSb alloy systems with melting points exceeding 217°C. Certain specialized formulations achieve melting points as high as 280°C (e.g., gold-tin alloy solder paste). This property directly addresses two major thermal challenges in LED packaging:

Prevents Solder Joint Remelting: In dual-side reflow processes, its melting point far exceeds peak reflow temperatures (typically 170-200°C), ensuring joint stability during repeated heating cycles and preventing component cold soldering or detachment.

Adaptation to High-Power Applications: LED chips generate heat during operation, particularly in high-power LEDs (e.g., automotive lighting, outdoor displays) where junction temperatures may exceed 100°C. Fitech high-temperature solder paste maintains over 95% joint strength during prolonged high-temperature operation, effectively resisting thermal fatigue and preventing joint cracking.

II. Reliable Soldering Performance: Dual Assurance of Mechanical and Electrical Properties

Fitech high-temperature solder paste delivers significantly superior soldering results compared to low-temperature pastes, specifically:

High Mechanical Strength: The shear strength of SAC alloys exceeds 40 MPa, significantly surpassing low-temperature pastes (e.g., Sn-Bi alloys at 20-30 MPa). In Mini LED packaging, adding trace metals like nickel (Ni) and cobalt (Co) as reinforcing phases further boosts joint shear strength to over 50 MPa, effectively preventing chip fractures caused by stress concentration.

Stable Electrical Properties: Post-soldering residues are minimal and appear as white transparent material with high insulation resistance (>10¹⁰Ω), eliminating short-circuit risks from electrochemical migration. Additionally, its low void content (typically <5%) reduces thermal resistance, aiding LED chip heat dissipation, delaying lumen depreciation, and extending device lifespan.

III. Stable Material Formulation: Chemical Advantages Adapted to Complex Processes

Composition Stability: The SAC alloy's composition ratio has undergone long-term optimization, offering moderate wettability that accommodates varying grades of soldering equipment. Soldering can be completed without nitrogen-filled environments.

Superior Printing Performance: Minimal viscosity variation ensures operability on stencils for over 8 hours. Retains original shape for hours post-printing without collapse, preventing component misalignment.

Robust Environmental Resistance: Halogen-free flux addresses high-humidity outdoor displays. Residue exhibits high surface insulation resistance, preventing corrosion and leakage. Its high-temperature resistance (melting point 220-250°C) also makes it suitable for extreme environments like automotive displays.

IV. Application Scenario Adaptability: Full-Scene Coverage Enhances Reliability

Fitech high-temperature solder paste's stability advantages have been validated across diverse LED packaging scenarios:

Traditional LED Packaging: Demonstrates high reliability in packaging power transistors, diodes, and other components, resisting solder joint failure and cracking—particularly suitable for high-frequency soldering and heat sink module assembly.

Mini LED Packaging: Mini LED chips feature small dimensions (typically <200μm), demanding superior solder paste particle size, process performance, soldering characteristics, and temperature resistance. Fitech addresses Mini LED packaging challenges in precision, thermal management, and uniformity through its core material formulation: ultra-fine tin powder (5-15μm), high thermal conductivity alloy (65-70W/m·K), and specialized high-temperature resistance (melting point 220-250°C).

High-Reliability Applications: Fitech's gold-tin solder paste (melting point 280°C) delivers stable printability/dispensing performance, excellent post-soldering mechanical strength and conductivity, making it suitable for high-reliability joint preparation in aerospace, defense, power semiconductor, and other critical sectors.