MOSFETs combine compactness with reliability
In recent years, the growing number of safety and comfort systems in vehicles has resulted in the space for these systems becoming increasingly limited and the demand for smaller components increasing. To meet these requirements, there is growing interest in MOSFETs with floor electrodes whose dimensions can be further reduced with the same high current.
In order to guarantee the quality of automotive applications, an optical inspection is carried out during assembly. In the case of components with bottom electrodes, however, the solder height cannot be inspected after assembly. This makes it difficult to guarantee the quality of the solder joints. Rohm is now the first company to use its proprietary Wettable Flank technology to ensure the 130 µm electrode height required for automotive applications. The result is consistent solder quality, even for products with bottom electrodes, so that automatic inspection machines can easily check the soldering conditions after assembly.
With Wettable Flank technology, a cut is made in the lead frame on the underside of the housing before coating. However, burrs can occur which occur more frequently with increasing height of the cut. In order to minimize this burr formation, Rohm developed a process that introduces a barrier layer on the entire surface of the lead frame. This process not only prevents the erection of components and soldering errors during assembly, but also guarantees an electrode height of 130 µm on the underside of the DFN161616 package (1.6 mm x 1.6 mm) for the first time.
Until recently, Schottky barrier diodes (SBDs) were mostly used in the reverse polarity protection circuits of ADAS camera modules. However, since high-resolution cameras in modern vehicle systems require higher currents, SBDs are increasingly being replaced by compact MOSFETs with low turn-on resistance and lower heat generation.
For example, conventional automotive MOSFETs can reduce the placement area by 30% compared to SBDs with a current and power consumption of 2.0 A and 0.6 W, respectively. However, the use of bottom electrode MOSFETs that provide excellent heat dissipation while supporting high currents allows up to 78% and up to 68% reduction in placement area compared to conventional SBDs compared to conventional MOSFETs.
The RV4xxx series includes versions with on resistors from typ. 75 mΩ to 400 mΩ and drain source voltages of 30V and 20V. The drain current is 3.1 A and 2.0 A respectively. The control voltage is specified at 4.0 V and 2.5 V respectively.
The RV4xxx series is available immediately in sample quantities and from September 2019 in OEM quantities.
More information: https://www.rohm.com/