During the past seven years, the Mayo Foundation has investigated the emerging electronic packaging approach referred to as Multichip Modules (MCMs), exploring a variety of MCM technologies' Our principal approach to evaluation of MCM technologies is through thedesign, fabrication, and measurement of so-called "test coupons", of both "passive" and "active" varieties. A representative test coupon 4-5 cm square is typically sufficiently large to include all desired passive or active test structures. Our passive test coupon contains a number of transmission line structures, via chains, verification sites for the test probes, and so on. Passive test coupons have been developed and tested, or are being developed, with Hughes (MCM-D), Texas Instruments (MCM-D, "chips first"), nCHIP (MCM-D, SiO2 dielectric), IBM (MCM-C and MCM-L), and ISA (MCM-D, "chips first"). Results from the measurements of these passive structures will be reported at this workshop.