Flying Leaded Substrates

Integrated power terminals (or lead-offs) are used to solve interconnection problems between high power circuits and the lower power driver circuits, or the high power connections and the outside world.

Where interconnect techniques like wire- bonding, jumpers and soldered terminals may be difficult, the ability to connect directly to FR4 PCBs using integrated terminals is seen as a great advantage.

The terminals can extend to the lower power section of the circuit as described and heavy power terminals can be taken from the same substrates to busbars since the DBC copper has excellent current carrying capability. The terminals can be bent to make connection or to provide strain relief in the lead.

Either pull back for increased isolation needs ispossible or S-shaped terminal geometries.

Design Rules

Ceramic thickness: 0.635mm, 0.381mm
Copper thickness: min 0.2mm preferred 0.3mm
Terminal length: ≤ 10mm ±0.5mm
Length of bonded area: > 5mm (198mil)
Terminal width: ≥ 1mm ± 0.2mm
Terminal spacing: ≥ 1mm ± 0.2mm
Pull back length: max. 1.5 ± 0.5mm
Width of ceramic ≥ min. terminal length