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Views: 0 Author: Site Editor Publish Time: 2026-08-19 Origin: Site
8. Which Application Scenarios Are More Suitable for CTMS?
GTMS can meet a large number of conventional application requirements, but when facing higher performance demands, CTMS has more significant advantages:
High-power lasers — require high thermal conductivity for heat dissipation; glass has very poor thermal conductivity (~1 W/m·K)
Microwave/millimeter-wave components — require extremely low dielectric loss; glass loss increases at high frequencies
High-temperature environments (>300°C) — glass softens; ceramics have temperature resistance ≥500°C
Strong shock/corrosive environments — ceramics are more shock-resistant than glass and more corrosion-resistant than glass in specific corrosive media such as hydrofluoric acid
These scenarios require Ceramic-to-Metal Sealing (CTMS).
9. Core Technology of CTMS: Ceramic Must Be “Metallized” First
CTMS uses alumina (Al₂O₃) or aluminum nitride (AlN) ceramics to replace glass.
But there is an inherent challenge: ceramic surfaces have covalent/ionic bond structures that are not wettable by metal brazing filler materials — the solder will not naturally spread.
Solution: Ceramic Metallization — creating a metal layer on the ceramic surface first, then brazing.
Two mainstream methods:
Mo-Mn or W Method: Applying molybdenum-manganese or tungsten paste, then high-temperature sintering to form a metallized layer
Active Brazing Method: Adding Ti, Zr, and other elements to the brazing filler, reacting directly with the ceramic without pre-metallization
10. GTMS vs. CTMS: A Clear Comparison Table
Comparison Dimension | GTMS | CTMS |
Insulation Material | Glass | Al₂O₃ / AlN Ceramic |
Long-term Temperature | ≤300°C | ≥500°C |
Mechanical Strength | Medium (brittle) | High (flexural ≥300MPa) |
Thermal Conductivity | ~1 W/m·K | Al₂O₃ ~20 W/m·K, AlN ~170 W/m·K |
High-Frequency Performance | Average | Excellent |
Cost | Lower, suitable for mass production | Higher, suitable for high performance |
Typical Applications | Sensors, connectors, optical communications | High-power lasers, microwave, aerospace |
Selection Principle: Normal/mid-temperature, cost-sensitive, mass production → GTMS; High-temperature, high-power, high-frequency, high-reliability → CTMS.
But selection is not the endpoint — after sealing, there is still a critical process.
[Next Article Preview] In the next article, we will examine how Surface Treatment and Plating determines the final reliability of the product.
