HOME > Product Information > Glossary        RoHS Directive This directive was enacted in July 2006 in the European Union and is formally known as the Restriction on Use of Hazardous Substances in Electrical and Electronic Equipment. With some exceptions, this regulation bans the use of the following six substances: mercury, hexavalent chromium, lead, cadmium, polybrominated biphenyl (PBB) and polybrominated diphenyl ether (PBDE). Manufacturers in Japan are currently complying with this directive.  Whisker In plating, this is a single crystal-like "whisker" generated on a film of tin, zinc, aluminum, or other element. In the past, tin plating applied to electronic components would produce whiskers that would grow to several hundred µm, creating problems such as electrical short-circuits in wiring. We have prevented the generation of whiskers by using tin-based alloys (such as lead) instead of tin. To date, no definitive explanation has been offered on the cause of whisker generation; the mainstream opinion is that whiskers are generated as a result of internal stresses in the plating film.  Lead-free solder plating In the past, whisker generation was controlled with the use of solder plating (Sn-10%Pb) for connections of electronic components. Under the RoHS Directive, however, the use of lead has been restricted since 2006; consequently, lead-free solder plating was developed. The main varieties are tin, tin-bismuth alloy, tin-copper alloy, and tin-silver alloy.  Solder wettability In order to confirm the reliability of solder joints in plated products, solder wetting tests such as the meniscograph method and solder immersion method are conducted. The meniscograph method shows the process of the gradual wetting of the product inside the solder melting tank. This method has been used frequently in recent years because measurement of the zero cross time quantitatively reveals solder wettability.   Product Information Types of Plating The Plating Process Glossary HOME     METEK KITAMURA CO., LTD. 1 Warata, Kamitoba, Minami-ku, Kyoto 601-8133, JAPAN TEL +81-75-661-4900 FAX +81-75-681-2039       Copyright © 2006 METEK KITAMURA CO.,Ltd. All rights reserved.