Rapid prototyping of time-based PDIT for substrate networks [MCM]

A parallel digital interconnect test (PDIT) method was introduced in previous publications (Newman and Keezer, 1997; Newman et al, 1998). This method transmits unique digital test patterns through the substrate networks to detect catastrophic faults such as opens and shorts with 100% accuracy. The detection of resistive faults is limited, however, due to the TTL logic thresholds present in the FPGAs used to implement the test channels. A new method called time-based PDIT (T-bPDIT) was developed to overcome these limitations (Newman and Keezer, Int. J. Microcirc. and Electronic Packaging, vol 23, no. 1, pp. 1-7, 2000). The mixed-signal method not only measures the analog properties of the network in parallel, but also maintains the ability to transmit and receive the digital test patterns originally used in PDIT (Economikos et al, 1994; Kurtz, 1974). An overview of PDIT, and the methods used to implement T-bPDIT will be discussed in detail