Varistor Metal Oxide Varistor Products Page 35 Varistor Metal-Oxide Varistor Products

2017 Littelfuse, Inc. Specifications are subject to change without notice. Revised: 09/14/17 Metal-Oxide Varistors (MOVs) Surface Mount Multilayer Varistors (MLVs) > 0201 MLA Series T 1 T 2 100 50 0 O 1 TIME PERCENT OF PEAK VALUE T Peak Pulse Current Test Waveform for Clamping Voltage 0 1 = Virtual Origin of Wave T = Time from 10% to 90% of Peak T 1 = Rise Time = 1.25 x T T 2 = Decay Time Example - For an 8/20 s Current Waveform: 8 s = T 1 = Rise Time 20 s = T 2 = Decay Time Reliability and Environmental Specifications Judge Criteria Test Condition Solderability > 95% solder coverage 245 +/- C, 3 +/- 1 sec. Leaching Resistance > 95% solder coverage 245 +/- C, 3 +/- 1 sec. High Temperature Exposure Vv / Vv < 10% 1000 hours 85C, un-powered Thermal Shock Vv / Vv < 10% -45 to +85 C, 30 min. cycle, 5 cycles Operating Life Vv / Vv < 10% 85 C, DC working voltage 1000 hours Bias Humidity Vv / Vv < 10% 40 C / 85% RH, DC working voltage 1000 hours Multilayer Internal Construction GRAINS DEPLETION FIRED CERAMIC DIELECTRIC REGION METAL ELECTRODES DEPLETION REGION METAL END TERMINATION To avoid the possibility of generating stresses due to thermal shock, a preheat stage in the soldering process is recommended, and the peak temperature of the solder process should be rigidly controlled. When using a reflow process, care should be taken to ensure that the ML chip is not subjected to a thermal gradient steeper than 4 degrees per second; the ideal gradient being 2 degrees per second. During the soldering process, preheating to within 100 degrees of the solder's peak temperature is essential to minimize thermal shock. Once the soldering process has been completed, it is still necessary to ensure that any further thermal shocks are avoided. One possible cause of thermal shock is hot printed circuit boards being removed from the solder process and subjected to cleaning solvents at room temperature. The boards must be allowed to cool gradually to less than 50 C before cleaning. Lead-free (Pb-free) Soldering Recommendations MAXIMUM TEMPERATURE 260 C, TIME WITHIN 5 C OF PEAK 20 SECONDS MAXIMUM PREHEAT ZONE RAMP RATE <3 C/s 60 - 150 SEC > 217 C TEMPERATURE C TIME (MINUTES) 300 250 200 150 100 50 0 0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 Disclaimer Notice - Information furnished is believed to be accurate and reliable. However, users should independently evaluate the suitability of and test each product selected for their own applications. Littelfuse products are not designed for, and may not be used in, all applications. Read complete Disclaimer Notice at www.littelfuse.com/disclaimer-electronics.

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