The BPW21 has (according to the Siemens '94/'95 data book) a "filter glass lens" Schott BG 18/0.3 mm.Hello! I have to order it by mail so has anyone worked with this diode and can tell me whether it has a glass lense that I can cut away or is the whole space covered with a plastic substance (epoxy). An alternative diode for me seems to be the BPW 21 (lense or plastic?). The osram datasheet says nothing to this aspect (but who wants to cut a diode in pieces?)I can not see whether the BPW21 has a plastic or glass window. It lookes molded, but that can be done before the chip was encapsulated. The window is rather hard because I can not scratch it with a steel pin. So glass is probable. It does not look epoxy filled. The shadow of the rim moves over the bottom and you cannot see refraction fenomena. Also inside it looks very bright.regards, Harry
More than you ever want to know about this glass can be found on:
http://www.besoptics.com/html/body_schott_bg18_filter_glass.htmlThis filter is used to adapt the wavelength response (spectral sensitivity) to that of the eye.
Regards, Tinco.
