Select tape and conductor together
LTCC is not a single chemical formula. The dielectric tape, via fill, conductor and firing atmosphere are a qualified set. Systems may use copper, silver or gold conductors. Swapping one part of the set can affect shrinkage, adhesion, electrical loss and dimensional stability.
Check the properties relevant to your frequency
Use dielectric constant and loss tangent at an appropriate frequency and with the stated test method. CTE varies substantially between LTCC grades. Kyocera’s GL570, GL580 and GL773 examples illustrate why a single generic LTCC number is inadequate for board-level stress or RF modeling.
Design heat paths deliberately
Many glass ceramics conduct much less heat than AlN or mainstream power-substrate ceramics. Thermal vias and package heat paths may be needed beneath active devices. Model the conductor fill, via network and interfaces rather than treating an LTCC package as a uniform block of high-conductivity ceramic.
Engineering example
A compact filter module may favor LTCC even if its bulk thermal conductivity is low. Embedded routing and passives can reduce interconnect length; the active device still needs a separately verified heat path.
Before you release the design
- Freeze the tape/conductor system.
- Obtain shrinkage and design-rule data before layout.
- Distinguish RF integration from power-substrate cooling.
Sources and further technical reading
Manufacturer references support the material and process context. Worked examples and checklists are engineering guidance; they are not test results or supplier guarantees.