Not only is the environment challenging, but also automotive electronics systems have to be some of the most reliable - especially where safety is concerned. Notwithstanding this, cost is always a key requirement - and many systems require certification, which can add to the cost.
In order to address a number of these challenges, leading manufacturers of semiconductor devices - including MOSFETs - continue to innovate new technologies, enabling existing applications to be better fulfilled and sometimes facilitating new applications. While the fundamental semiconductor technology behind MOSFETs continues to evolve, recent innovations have fundamentally improved the package technology - and the improvements are especially relevant for automotive applications.
Currently, the de-facto standard for MOSFET packaging is currently the DPAK - a surface mount device with three pins and a large mounting tab for thermal conduction and physical strength. The small size and convenient tape-and-reel packaging have made the format very popular, especially in automated manufacturing environments.
Despite its popularity, the DPAK does have some drawbacks. Many of today's ultra-thin designs (especially those found in the confines of automotive applications) use components that are substantially lower profile than the DPAK's 2.3mm height. Also, the wire bonds that connect the semiconductor die to the leadframe in a DPAK limit thermal and electrical performance. These wire bonds are very thin (~70um) and, even when multiple bonds are used in parallel; they limit the thermal performance and current capability of the DPAK as well as restricting the ability to reduce R DSON to the low levels demanded by modern power-related designs.
To address these limitations, On Semiconductor has recently introduced the ATPAK (‘Advanced Thin PAcKage’) as a next-generation package for modern power designs.
The ATPAK has a height of just 1.5mm, compared to