Design for modular testing of a multilayer flexible wireless multisensor platform

Smart wireless sensor systems that incorporate multiple sensors often cannot be implemented on a single chip. Advanced packaging and assembly type integrations allow for a more complex conjugation and configuration of multiple system modules implemented under different technologies together in a small tiny package. In tiny sensor systems such as these, a common challenge seen across various unique assemblies is the limited test access during assembly, allowing system verification only after completion of assembly and packaging. Conventional test point access is too large to be suitable and cost effective for testing in tiny systems, while microprobing is only appropriate for a small number of test points and prototypes. We introduce a concept of direct test points access through printed microconnectors for a system that consists of multiple stacked layers of electronics disposed on a flexible polymer carrier. The printed microconnectors provide test access to various modules of the system during assembly such that progressive verification can be performed prior to completion of the entire system. This allows early identification of failed modules leading to production cost savings. The architecture of the flexible wireless multisensor platform and design of the microconnectors are discussed. The methodology and configuration for modular testing is explained from the system and subsystem perspective.