Substrates for high frequency SiP and MCM packages are not only subject to form factor requirements; they must also provide superior RF properties in combination with good heat diffusion and controllable thermal expansion. By combining the latest multilayer LCP fine-line substrate technology with a targeted use of laser cavities and metallic heat-sinks, DYCONEX has achieved an optimized interconnect design that accomplishes all of these desired performance characteristics.
Liquid Crystal Polymer (LCP) substrates demonstrate superior performance across a wide range of the RF spectrum, and remain stable even under harsh environmental conditions such as extreme temperature and humidity. To make best use of LCP's material and electrical properties, it is advantageous to have the signal traces guided through an inner layer with shielding above and below. Laser-generated cavities then allow for direct access to these inner layers, and thus circumvent the need for microvia interconnect. This combination ensures ideal signal integrity from the die to the next packaging level.
Since high frequency semiconductors are often high power devices as well, the heat generated by these devices during operation has to be dissipated effectively. To achieve this purpose, DYCONEX has combined LCP substrates with various forms of metallic carriers. An opening in the substrate allows a direct attachment of the die on to the carrier. Subsequently, small wire wedge-wedge bonding is utilized to interconnect.
The thermal expansion factor of the entire package is primarily controlled by the metallic carrier due to its higher stiffness. This reduces the thermal mismatch of the die to the substrate and consequently improves the RF packages reliability.
© 2016 Micro Systems Technologies, CH-6340 Baar, Switzerland
DYCONEX AG, CH-8303 Bassersdorf, Switzerland