Advances in Backend Wafer-Level Test Infrastructure for High-Power Discrete Devices: A Decade of Throughput, Yield, and Capability Gains

Abstract

Wafer-level test (WLT) infrastructure for high-power discrete devices has evolved substantially over the period 2014 through 2024, driven by the parallel demands of automotive electrification, industrial-drive power-conversion, and large-scale renewable-energy inverter applications. This review consolidates the throughput, yield-capture, and parametric-coverage gains achieved across the decade, with particular attention to the transition from sequential to parallel test architectures, the introduction of in-situ thermal characterization, and the deepening integration with backend assembly traceability. We analyze the test-economics implications of these developments and identify the open challenges expected to dominate the 2025-2030 horizon, including ultra-low-leakage wide-bandgap device qualification and wafer-level reliability stress.