Outline of LTCC

Basic knowledge concerning LTCC
- Outline of LTCC -

LTCC is an abbreviation of Low Temperature Co-fired Ceramics. High purity ceramics used in the industrial world are also called "fine ceramics." Among fine ceramics, LTCC is classified as electronic ceramics which are used as electronic materials.

Normal electronics ceramics are fired at a temperature of at least 1500°C. Because they are fired at a high temperature, the circuit electrodes are made of a fire-resistant metal (e.g. tungsten or molybdenum) . Along with the use of increasingly high frequency electrical signals, characteristics issues such as the delay in signal propagation due to the high electrical resistance of these metals became noticeable. This led to the development of ceramic circuit boards which used metals with low electrical resistance.

Murata's LTCC are made by mixing a glass component with an alumina ceramic, enabling the firing temperature to be reduced to no more than about 900°C. This in turn enables metals with low electrical resistance such as silver or copper to be used for the wiring of the internal layers.

- Board material characteristics table -

Murata's LTCC board materials consist of the "LFC®" Series which have a solid reputation in the automotive industry, and also the "AWG" Series which are used mainly for communication applications.

The LFC® Series offers extremely flat module boards due to the use of a resistor printing system, which has stable characteristics, and also a "pressurized firing method," while the AWG Series offers compact module boards which have built-in inductors and capacitors, reduced height due to the use of thin layer tape, and other features, based on Murata's material technology fostered through its achievements with electronic components.

Both series are based on Murata's unique board material system. We offer customers the most suitable boards for their particular applications.

Material characteristics

  Unit AWG LFC
Ceramic Compositions   CaO - Al2O3 - SiO2 - B2O3 + Al2O3
Conductor Material   Ag
Bulk Density (Apparent Specific Gravity) g/cm3 3.2 2.9
Flexural Strength Mpa 300 270
Thermal Expansion Co-efficient ppm/°C 7.2 5.5
Dielectric Constant (@1MHz)   8.8 7.7
Thermal Co-efficient of Dielectric Constant ppm/°C 150 110max
Q (@6GHz)   240 250
Thermal Conductivity W/m・K 3.5 2.5
Insulation Resistance between Layers Ω 1010min
Break-down Volage kV 5min (layer thickness 300µm)

Murata Icon X Basic knowledge concerning LTCC