A chips-first multichip module implementation of passive and active test coupons utilizing Texas Instruments' high density interconnect technology

In this paper, we describe the development and measurement of two separate test structures, or "coupons" to assess the performance of Texas Instruments' "chips-first" multichip module technology at high operating clock rates, A "passive" coupon containing a variety of microstrip and stripline transmission line structures allowed the measurement of DC and AC signal amplitude losses in long conductors, as well as assessments of crosstalk and reflections as functions of line dimensions and spacings. An "active" coupon containing 16 interconnected gallium arsenide (GaAs) chips of two separate designs allowed the assessment of this MCM technology's ability to support the propagation of digital signals at clock and pulse rates above 500 MHz, and the ability of the power and ground plane structures to deliver clean power to the operating components. These comprehensive tests have allowed the development of design rules for developing future high performance systems using this unique packaging technology. Finally, comments are presented regarding future directions for this technology to lower manufacturing costs while preserving the high levels of operational performance demonstrated by these tests.