Automotive SMT large-area photodiode for rain detection

November 14, 2017 //By Julien Happich
The SFH 2200 A01 and SFH 2200 FA A01 chips from Osram Opto Semiconductors are what the company claims to be the world’s first SMT package for large-area photodiode chips complying with the strict demands of the automotive industry, rated for operation at up to 125°C.

Qualified to AEC-Q101-C, the 4.0x5.1x0.85mm photodiodes are ideally suited for use in rain sensors mounted behind car windshields. When a raindrop falls on the windshield the diodes detect a change in the incidence of light. This change is then translated by the system to control the windshield wipers and the rate at which they operate. Developers at Osram Opto Semiconductors have succeeded in significantly improving the moisture sensitivity level (MSL) to 2. This index is used to determine when the amount of moisture in the component is high enough for damage to be caused during soldering. Customers can solder photodiodes in their circuit up to a year later without the possibility of damage. This translates into extraordinary flexibility for the work processes. Comparable products have an MSL of 4, which means, for example, that after only 72 hours there is no guarantee that the component can be soldered without causing damage. The company used an encapsulation material containing silicone, which allows moisture and gases to escape more quickly during soldering. The SFH 2200 FA A01 has a daylight filter whereas SFH 2200 A01 does not.

Osram Opto Semiconductors - www.osram-os.com