5G Wafer Test and the New Age of Parallelism
The development of new RF devices (5G and high-speed digital components) is changing the landscape for RF probing. For many years, RF probing in frequencies beyond cell phone and WiFi frequencies was a niche area, only requiring a very small number of lines as well as not meeting the needs for High Volume Manufacturing (HVM). 5G is leading the way to both higher RF frequencies with the added 28, 38, and 60 GHz bands, as well as the needed improvements in infrastructure with high-speed digital devices for data backhaul through the fiber network because of the expected large increase in data needs. The race to meet higher bandwidth for infrastructure development is leading to a new set of requirements because of the increase in channels and volume. Because of this, the requirement for more parallelism at high speeds is leading to new probe card architecture. This includes frequency improvements of vertical MEMS type probe heads, and membrane probe cards with PCB active circuitry to increase the channel density. In addition, to meet the high standards for signal integrity at these high speeds, the relative repeatability of RF measurements per touchdown, RF calibration performance, and probe head inductance comparisons will be reported in order to provide a path for probing technology selection based on the end-use requirements.