Capacitors Get Smaller, More Energy Efficient

October 8, 2007

4 Min Read
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Capacitor manufacturers have been under pressure to innovate. The market wants smaller components as handheld devices become more complex. Plus, there is growing interest in energy efficiency. Consumers want green products and battery life has become a growing concern when handheld products are now running multiple functions, from Web access to video playback.

The demand for ultracapacitors and tantalum keeps growing due to the need for improved durability and higher performance. Another trend is toward greater flexibility. Suppliers are developing capacitors that can take the shock of a dropped handheld and won't crack when the board bends.

FF-CAP Merges Two Capacitor Technologies

Kemet Corp. expanded its X7R Multilayer Ceramic Capacitor Flex Mitigation portfolio with FF-CAP. The FF-CAP incorporates two existing Kemet technologies, Floating Electrode (cascading electrode design) and Flexible Termination. The Floating Electrode component yields improved voltage and ESD performance over standard designs and also mitigates the risk of low-IR or short-circuit failures associated with mechanical flex cracks. The Flexible Termination component incorporates a measure of flexibility to the capacitor, shifting flex stress sway from the ceramic body and into the termination area.

FF-CAP's technology combination was designed to ensure an increased measure of protection from board flex, offering up to 5 mm of flex-bend capability. This provides customers with an enhanced level of mechanical flex crack protection for low- to mid-capacitance part types and complements Kemet's current Open Mode, Floating Electrode and Flexible Termination technologies. In addition, the new product meets the requirement of the Automotive Electronic Council's AEC-Q200—Rev C and is being offered with 100 percent pure matte tin-plated terminations that allow for excellent solderability.

http://rbi.ims.ca/5406-574

Capacitors Developed for 260C Reflow Soldering

NCI Components Corp. has introduced six new series of SMT V-Chip capacitors that feature 260C soldering heat ratings. The liquid electrolyte, aluminum electrolyte capacitors are compatible with the requirements of Sn-Ag-Cu (SAC) alloy lead-free soldering process. Common SAC solder alloys have a melting point of 217C. A peak reflow soldering temperature of between 12 and 43C above melting is typically recommended (by solder alloy makers) in order to achieve good wetting and to form a quality solder joint. The time period above melting point should be dependent upon the application/assembly. SAC solder alloys have emerged as the industry standard replacement for Sn-Pb solder alloys that were used extensively prior to the implementation of RoHS legislation.

The new NASE, NAWE, NAWT, NAZT and NAZU series from NIC were designed to provide designers with an extensive choice of devices for use in applications that demand characteristics such as low ESR, wide operating temperature range and small form factors. The available case diameters for 260C soldering heat rated capacitors are 4, 5, 6.3 and 8 mm. Larger case sizes — 10, 12.5 and 16 mm are rated for 250, 240 and 235C peak reflow temperatures respectively.

http://rbi.ims.ca/5406-575

Capacitor Minimizes Short-Circuit Failure

AVX Corp. has designed a ceramic capacitor that mostly eliminates the risk of short-circuit failure. These Flexisafe capacitors absorb shock and prevent internal cracking due to board flexure and temperature cycling damage. Flexisafe components are also structured with a cascade electrode design — effectively two capacitors in series within one MLCC — that protects the ceramic capacitor from low insulation resistance failure that may result from thermal stress, repetitive strike ESD or placement damage. "By combining our Flexiterm technology with the cascade design traditionally used in our high-voltage ceramic capacitors, the internal design of these capacitors minimizes all major causes of short-circuit failure," says Tim Hollander, product manager at AVX.

Flexisafe capacitors are suited for new designs in military/aerospace COTS applications, automotive terminal 30 and terminal 15 applications to replace the two capacitors in series requirement, as well as other safety-critical design. The Flexiterm technology is a soft termination system that allows almost three times the amount of board flexure when compared to standard termination systems. Flexiterm was developed as an additional flexible termination layer added to the component to ensure electrical integrity is maintained when external forces are applied and to prevent cracking.

http://rbi.ims.ca/5406-576

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