Mixed assembly placement usually calls for three operations. Those are surface mount (SM), plated through hole (PTH), and in most cases implementing heat sinks, cables, or press fit connectors for PTH I/O communications. But now with high speed designs becoming more prominent, some of those connectors are converted from PTH to SM due to SM/s tighter tolerance.
Design-for-manufacture (DfM) thus becomes an increasingly important aspect of mixed assembly placement at the design layout stage. The OEM and EMS provider should therefore investigate certain considerations to assure mixed assembly placement is ultimately performed correctly.