A comparative analysis of RF-characteristics of high-density MCM-L technologies

The well known Motorola Reliability Test Vehicle (MRTV) activities have only recently been transferred to the Interconnection Technology Research Institute (ITRI). In 1977, an improved version of the Motorola MRTV-2.2, now ITRI-TV2.4A, was manufactured. 18 technologically different samples were submitted by 16 manufacturers worldwide for testing. ITRI-TV2.4A has been designed to be compatible with all major classes of high density MCM-L technologies based on photo-defined, laser ablated, mechanically punched, and plasma etched via generation. Besides various reliability test structures that occupy most of the routing area, some space is reserved for dedicated RF test structures. The Electronics Lab of ETH Zurich is responsible for development and measurement of these structures. In this contribution, the suitability of the different technologies for high frequency designs is compared on the basis of key characteristics such as propagation delays and dielectric losses. These performance figures are derived form vector network analyzer (VNA) and time domain reflectometry (TDR) measurement set-ups. The paper gives a brief introduction into the special conditions for RF design on very thin laminate substrates. Then, a comprehensive summary of recent RF measurement results obtained from ITRI-TV2.4A is presented. The paper concludes with an overview of the developmental status of the involved major classes of MCM-L fabrication technology.