Unlike the first solution using thick-film copper, the use of wirelaid technology does not impact the costs negatively. The additional costs for the wire are balanced out, for example by the savings made for the reduction in layer pairs and the use of standard copper thicknesses. An additional cost benefit is the reduced PCB dimensions as opposed to the dimensions achieved using thick copper technology.
Fig. 5: PCB 3D simulation using CAD data exported from Allegro & Nextra
To calculate the heatsink requirements, the PCB manufacturer using wirelaid technology has translated its experience into mathematical formulae. The calculation results were very close to the actual readings obtained in test measurements and a temperature difference of 20K was found compared to thick copper technology. A further advantage of wirelaid technology is that the surfaces are very planar and do not differ from standard PCBs built with 35µm technology.
PCB’s in wirelaid technology can conduct very high currents. This property is one of the core requirements for the use of PCB-based modules such as MiniSKiiP or SEMITOP (power modules produced by Semikron, where, for example, +DC, -DC and AC load connections are routed through the PCB). This technology uses far less space than conventional thick-copper PCBs.
Since circular and ribbon wires take up far less space on the PCB than special power layers, the number of layers can often be reduced. This technology can easily be designed with all of the individual design stages of the scaleable cadence PCB Design solution from OrCAD and Allegro.
Peter Mauer is head of electronics design at Semikron Elektronik .