OptiMOS TOLG for improved TCoB robustness
With the innovative TO-Leadless (TOLL) package, Infineon now offers two new OptiMOS power MOSFET packages in the TOLx family: TOLG (TO-Leaded with Gullwing leads) and TOLT (TO-Leaded Top-side cooling). Together, the TOLx family offers very low R DS(on) and a high-current rating over 300A to increase system efficiency in high-power density designs.
Applications such as e-scooters, e-forklifts and other light electric vehicles (LEVs), as well as power tools and battery management systems, demand high current rating, ruggedness and extended lifetime. Infineon Technologies has addressed these requirements by offering more choices to power system designers to meet diverse design needs and achieve maximum performance in the smallest space.
The TOLG package combines the best features of TOLL and D 2PAK 7-pin packages, sharing the same 10x11mm 2 footprint and electrical performances as TOLL with added flexibility comparable to D 2PAK 7-pin. The main advantages of TOLG are particularly apparent in designs with aluminum-insulated metal substrate (Al-IMS) boards. In these designs, the coefficient of thermal expansion (CTE), which describes the tendency of a material to change its shape in response to changes in temperature, is higher than copper-IMS and FR4 boards.
Over time, temperature cycling on board (TCoB) causes a crack in the solder joint between the package and the PCB. With the flexibility of the gullwing leads, TOLG demonstrates excellent solder joint robustness, significantly increasing product reliability in applications where repetitive temperature cycling takes place. The new package achieves two times higher TCoB performance compared to the IPC-9701 standard requirement.
The TOLT package is optimised for superior thermal performance. Constructed with its lead-frame flipped to position exposed metal on the top side, the package contains multiple gullwing leads on each side for high current carrying drain and source connections. With a flipped lead-frame, heat passes from the exposed metal top side, through the insulating material, directly to the heatsink.
Compared to the TOLL bottom-side cooling package, the TOLT improves R thJA, by 20% and R thJC by 50%. These specifications enable a lower bill of material cost, particularly for the heatsink. In addition, OptiMOS in TOLT reduces PCB space, as components can now be mounted on the bottom of the MOSFET.
The OptiMOS TOLx family will be available across a wide range of voltage classes in OptiMOS 3 and 5 technology. TOLG will be available in the fourth quarter 2021 from 60V to 250V in a broad product portfolio, including best-in-class and price/performance-optimised products. TOLT is currently available in 80V and 100V voltage classes. An evaluation power board is also available, featuring a 100V OptiMOS 5 power MOSFET in a TOLG package.