The ongoing trends in electrification of automobiles, trucks and commercial transportation systems are driving a series of important changes in the way inverters and power modules are designed, manufactured and integrated with other systems in the vehicles.
Typically, modern inverters are built around high-power insulated-gate bipolar transistors (IGBTs) that handle all of the electronic switching functions at the heart of the process. A number of subassemblies and components, such as control boards, busbars, current sensors, capacitor banks, cooling circuits, etc., surround the IGBT. When integrated together, all of these elements comprise the functional inverter stack.
Traditional interconnect methods in IGBT power module packaging, such as bolting and welding harness connections cannot keep up with today’s requirements because they are inefficient, cumbersome, and assembly-process intensive. They result in larger assemblies with longer current paths and higher overall inductance.
In contrast, the efficient design of IGBT inverters and power module integration by using pluggable, high-force, press-fit technology can significantly improve power efficiency, reduce the bill-of-material costs, decrease assembly complexity and shrink the overall physical size of the power assembly.
According to the automotive industry report EV/HEV Power Electronics in Electric and Hybrid Vehicles
(Published by Yole Développement Nov. 2014):
“Inverters, and more importantly power modules, are fast becoming one of a car’s key ingredients, and car makers want to control it. In this context, the supply chain is evolving and power module manufacturing is becoming a difficult concurrence zone. Pre-established business models must be reshaped. Tier 1 companies in particular must integrate power modules to stay competitive, taking into account that more and more car makers are moving to vertical integration as well.”
As the hybrid and electric vehicle markets ramp up to high volumes and inverters become both more powerful and more critical, Tier 1 suppliers and auto manufacturers are looking for ways to improve power system efficiency and manufacturability.
In order to achieve these objectives, OEMs need new interconnect and packaging approaches that deliver high power efficiency, more compact form factors and support for integration of multiple inverter stacks. Each requires tighter integration from the chip-level through the module level, with shorter electrical paths, fewer connections and simpler packaging.
To learn more about these trends in automotive inverter module design and the interconnect solutions that are enabling higher efficiency and lower cost, Download the Tech Bulletin on Automotive Inverter Power Module Design
