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40 DESIGN007 MAGAZINE I SEPTEMBER 2018 The value range for these two thin-film inductor components is between 1.0 nH and 82 nH with a tolerance of +/-2%. Manufac- turers claim that the miniature inductors fur- nish up to twice the rated current and half the DC resistance of comparable ferrite inductors. Designers should be aware that inductors size and value range varies somewhat between suppliers. Next Column Part 4 of this embedded component technol- ogy series will focus on land pattern develop- ment criteria, ways to accommodate higher profile passive components, and alternative termination methodologies. Upcoming Appearance Vern Solberg will be conducting a half-day professional development course on "Design and Assembly Process Principles for High- Density Flexible and Rigid Flex Circuits" at SMTA International 2018 in Rosemont, Illinois, on Sunday, October 14 from 8:30 a.m.–12:00 p.m. This tutorial has been developed primarily for design professionals with a focus on apply- ing best design practices for fabricating flexible and rigid-flex circuits. Participants will have an opportunity to study and discuss alterna- tive fabrication methodologies as well as prac- tical guidelines for implementing automated assembly processing. Information presented will also include the selection criteria for base materials, alternative fabrication methodolo- gies, SMT component selection, land pattern development, and features required to accom- modate SMT-on-flex assembly. For further information on this conference and to sign up for this tutorial (PDC 01), click here. DESIGN007 Vern Solberg is an independent technical consultant specializing in surface mount technology, microelec- tronics design, and manufacturing technology. To read past columns or contact Solberg, click here. ponents are available with the same small outline dimensions as the resistor family, but device thickness will vary somewhat due to the dielectric type and required volume. For example, the body thickness for the 01005 capacitor is specified as 0.20 mm while the 0201 outline component thickness can increase to 0.30 mm. Additionally, the dielec- tric type and working voltage will impose limits on the capacitor value range for these smaller device outline families. The 01005 and 0201 type capacitors with a C0G dielectric are available in a value range of 5–100 pF. The X7R dielectric capacitors can furnish a value range of 68–470 pF for the 01005 capacitor and 68–10,000 pF for the 0201 variation. The stan- dard terminal plating is tin-alloy over a nickel base metalization for solder and conductive polymer attachment. Because the base layer is a nickel-alloy, termination of the component to the circuit conductor pattern with copper- plated microvias may be possible. Discrete Inductors A limited value range of miniature inductors is available from several leading suppliers. The multilayer ceramic inductor family is avail- able in both 0402 and 0603 (1.0 mm x 0.50 mm and 1.60 mm x 0.80 mm) outlines with a thickness equal to the device width (0.50 mm for the 0402 device and 0.80 mm for the 0603 variation). The terminal plating is a nickel- alloy with a tin-alloy based coating for solder or conductive polymer interface. The available inductance value ranges between 6.8 nH for the low and 220 nH for the high with a tolerance value of +/-5%. An alternative thin-film small outline and low- profile inductor family is available too. For this variation, the inductor element is printed onto the surface of a ceramic base material, passiv- ated and fired to protect the printed pattern, and furnished with a tin-alloy terminal for joining to the circuit structure. Small outline thin-film inductor elements will range in size from 0402 to 0603. The actual dimensions for the 0402 device are 1.0 mm x 0.50 mm x 0.35 mm, and 1.6 mm x 0.8 mm x 0.50 mm for the 0603 device.

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