Lead-less transistor packaging

TOLL packages for two wheelers
(Image courtesy of Alpha and Omega Semiconductor)

Alpha and Omega Semiconductor (AOS) has developed lead-less packaging for its automotive grade 80V and 100V MOSFET transistors for two and three wheelers, writes Nick Flaherty.

The lead-less packaging is a key step in making battery packs and brushless DC motors smaller in two and three wheel scooters. Removing the leads inside and outside the package helps to lower the resistance to 1.25 mOhms and 1.7 mOhms, giving lower losses and allowing higher efficiency for light vehicles.

To achieve the lead-less packaging, AOS developed a clip for the transistors that supports a high in-rush current rating of 1780 A for the 80 V parts and 1480 A for the 100 V parts. The 80 V also has a continuous current of 247 A at a usable temperature of 100 C and is rated to 445 A at 25 C, while the 100 V parts support a current of 269 V at 100 C (and 370 V at 25 C).

This also means the parts have a 30% smaller footprint than the TO-263 (D2PAK) packages that are lead-less outside but still use bond wires to connect the die to the lead frame of the package. 

The lower resistance and inductance of the AOS TOLL packaging clip technology also improves the electromagnetic interference. This combination of low ohmic and high current capability allows designers to reduce the number of parallel MOSFETs in high current applications. This, in turn, helps to enable higher power density requirements without compromising reliability in applications where robustness and reliability are key design objectives.

“Using the AOS Automotive TOLL package with clip technology offers significant performance improvements in a robust package” said Peter Wilson, Marketing Sr. Director of MOSFET product line at AOS. “The advanced technologies in our AOTL66810Q and AOTL66912Q MOSFETs will help simplify new designs, allowing them to reduce the number of devices in parallel while providing the necessary higher current capability to enable overall system cost savings.”