Restriction of Hazardous Substances Directive a disadvantage because it can lead to lower quality electrical connections – can be used to place components more tightly than they used to be placed due to the properties of lead-containing solders. For example, Motorola reports that their new RoHS wireless device assembly techniques are "...enabling a smaller, thinner, lighter unit." Their Motorola Q phone would not have been possible without the new solder. The lead-free solder allows for tighter pad spacing. Research into new alloys and technologies is allowing companies to release RoHS products that are currently exempt from compliance, "e.g." computer servers. IBM has announced a RoHS
Constant phase element Constant phase element A constant phase element is an equivalent electrical circuit component that models the behaviour of a double layer, that is an imperfect capacitor. Constant phase elements are also used in equivalent circuit modelling and data fitting of electrochemical impedance spectroscopy data. A constant phase element also appears currently in modeling the behaviour of the imperfect dielectrics. The generalization in the fields of imperfect electrical resistances, capacitances and inductances leads to the general "Phasance" concept: http://fr.scribd.com/doc/71923015/The-Phasance-Concept The electrical impedance can be calculated: where the CPE admittance is: formula_2 and Q and n (0<n<1) are frequency independent. Q =