lead damage -- lead would be the wire or a connector what is attached to the resistor when it is manufactured .. it is broken off or damaged to the point that it affects the resistor performance (broken trace on a PCB is not resistor failure), drift -- is the undesirable change in resistance (even though it may be predictable) ... what causes it does not really matter in this context ... a thermistor value change due to temperature change is not drift ... but a difference in resistance for the identical temperature is drift, binding/sticking --- variable resistor adjustment mechanics not working smoothly ... there is a possibility that a resistor expands as it gets hot and it may have a mechanical device to adjust for the expansion (grasping at straws there), contaminated --- foreign substance on resistor affecting its properties (wirewound resistor that has a splatter of solder on it), seal leakage --- resistor may be rated for damp environments because it is inside a sealed jacket and the jacket has a crack in it. The current passes through an infinite number of branches connected in parallel which altogether creates a negligible inductance inside the resistor body. One favorite joke was an ATE test failure for tolerance on a zero ohm resistor ;), Click here to upload your image Thank you!!! Instead one solder direct on the press-fitted naked end caps. Terminations with the usual pitch 0.1″ (2.54 mm) are subjected to a mutual thermal influence at soldering. but still worked. Thin film SMD resistor • power operation Again, one single resistor product is suitable for two different classes of application by choice of the operating mode and the permitted power dissipation. Surface Mount (SM) resistors allow very large miniaturization. I think I understood all the topics with your help and @jsotola. It is important to remember that SM components, more than others, are influenced by temperature changes, especially for the larger component. I once had to know these specs and apply them in my 1st job in 1975 for Aerospace. They exist both as rectangular thick film chips as well as metal film MELFs. The key choice is biased where you want to focus the most effective corrective action. In electronics, the following trend is prevailing. Find (EEE) components/parts products and datasheets from hundreds of manufacturers. 2. what is the value that changes over time? TCRtrack for the thick film networks usually lies between 10 and 50 ppm/°C and for the thin film networks between 0.5 and 10 ppm/°C. Permissible maximum power of a MELF resistor can be calculated from the Equation below: Information about thermal resistance of the solder joint of standard components applies to solder conditions for normalized test board patterns. http://www.dtic.mil/get-tr-doc/pdf?AD=ADA259655. My analysis is that one or more LEDs in each string has a higher voltage to light it, instead of 3.2?? Sometimes metal foil chips are delivered for special custom trimming by a scribed line. The temperature dependence is strongly non-linear. The pulse power Pp should be limited to  and. The FMEA (failure mode and effect analysis) requires a full knowledge of each component's FIT (failure in time) and FMD (failure mode and distribution). In recent years another method of integrating resistors is introduced that is called buried resistors technology. The failure mode starts with flashing, then goes to blinking and then not lighting at all. The most common observed failure mode was a dislocation or evaporation of resistive material in a location suggesting a “hot spot”—heat generated in a spot of high energy density. In a third variant, a dispersion of graphite and binder is applied on a glass tube and then dried. The most typical failure mode of a capacitor is that the ESR has become quite high and therefore it cannot be considered to be a Low ESR capacitor anymore. Resistor Manufacturing Flow Example. It is closely related to the carbon composition. In general, thick film is cheaper to make but consume more of the material. By using our site, you acknowledge that you have read and understand our Cookie Policy, Privacy Policy, and our Terms of Service. Values down to 0.5 Ω/square ˜ and up to 1 GΩ/square ˜ are, however, quite possible. In the latter case, the carbon powder is mixed with a filling, usually silica or aluminum oxide, before it is molded. Discrete thick film chips are marketed down to 0302 or 0201 (0.8 x 0.5 respectively 0.6 x 0.3 mm). Cases, carbon composition resistor wire wound resistors fail due to its friction! Materials, only one remains to be mentioned: the conductive plastic metal films are designed to resistive... To 0302 or 0201 ( 1.1 x 2.2 mm ) is already well established in the latter case a... 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