Manufacturers of passive components have been quicker than some of their counterparts in the semiconductor market to post really quite detailed information of RoHS compliance issues on their websites.

A visit to the websites of suppliers such as AVX, Murata and Yageo will confirm that for the largest suppliers all chip capacitors and resistors, except perhaps a very small number of specialist parts, are available in production as lead-free, RoHS compliant parts.

Most passive component suppliers offer detailed information on lead-free component availability on their websites. For example, one of the more comprehensive can be found on the Welwyn TT Electronics website. It has been offering dates for lead-free/RoHS compliant availability for the last year. It also says that “either finish may now be supplied for a transitional period as stocks are exhausted”. However, “customers requiring guaranteed lead-free product before the end of the transition period must specify ‘Pb-free’ when ordering”.

Some suppliers, such as Epcos, list in some detail the compatibility of specific components with different standard soldering processes such as defined by the IEC 60068 and JEDEC 20 standards. It also shows maximum temperatures and temperature cycling information which can only give the user more confidence when selecting lead-free alternatives.

AVX is one supplier which, as well as offering a full range of lead-free parts, also takes the trouble to list those components which it will continue to offer with tin-lead terminations for use in RoHS exempt applications. AVX has recently announced the development of a tin-lead finish version of its TAP conformal-coated tantalum radial leaded capacitor, which was originally introduced as the first lead-free component of its kind in January.

Designated the TEP series, these capacitors are professional-grade devices manufactured with a flame-retardant coating and feature low leakage current and impedance and good temperature stability in very small packages.

The TEP series has a capacitance range of 0.1µF to 330µF with a capacitance tolerance of +/-10 per cent or +/-20 per cent. It is available in bulk and T&R packaging for automatic insertion. The wide range of capacitance, working voltages and case sizes enables TEP to accommodate almost any application.

NIC Components, as well as listing component availability, also offers additional lead-free standards and soldering information on its website.

There is specific information on terminal finish, barrier layer materials and moisture sensitivity levels. There is also component soldering information including the JEDEC 2nd level interconnect classification, lead-free test reports and wetting force information.

For its NTL series of surface mount thin-film inductors, NIC Components has wrapped a nickel barrier around lead-free terminations to be fully compliant with RoHS legislation.

The NTL series has a self resonant frequency of up to 10GHz, current rating up to 1.8A, and a high Q-factor across a wide frequency range - up to 52 at 1.5GHz. Precision tolerances are between 0.1nH and two per cent.

Similarly the RG range of precision metal-film chip resistors from Rhopoint Components use a nickel-chromium film resistive element with wrap around lead-free terminations and, according to the supplier, the surface mount resistors are suitable for all soldering methods including vapour phase reflow and wave soldering.

www.avx.com
www.epcos.com
www.murata.com
www.niccomp.com
www.vishay.com
www.welwyn-tt.com/leadfree/index.asp
www.yageo.com

See also: Electronics Weekly's roundup of content related to The ROHS Directive