1. Wired Test: Wired test fixtures have been the industry standard for functional test fixtures.wafer tester On PCBAs with lower probe counts or prototypes where the design may change, wired test fixtures provide an economical approach because they avoid non-engineering (NRE) costs. However, crosstalk and coupling problems can increase as the signal frequency increases. This is due to the wires being routed underneath the probe board, and coupling and crosstalk increase with frequency.

2. Wireless Test: Engineers have developed wireless test fixtures to address the limitations of wired test fixtures.wafer probe testing In wireless fixtures, a multilayer PCB called a Transition Board (T-Board) replaces the signal line set on the underside of the wired probe board. Automated PCB design software is used to route circuit alignments when wires are replaced. A double-ended probe connects the PCBA to be tested to the T-board.

3. Wireless devices are often more reliable than wired fixtures because PCB designers can precisely control how each trace is routed on the underside of the T-board,vibration isolation table allowing for isolation of troublesome signals. Repeated fixtures perform almost identically, and electrical parameters are very consistent because there are no wires and their induced variations. Reduced ground and crosstalk noise allows signals to bounce faster, which is especially important in low-voltage test applications.