NTC thermistors for temperature measurement Glass-encapsulated sensors, standard type Series/Type: B57540G1 Date: January 2018 (c) EPCOS AG 2018. Reproduction, publication and dissemination of this publication, enclosures hereto and the information contained therein without EPCOS' prior express consent is prohibited. EPCOS AG is a TDK Group Company. Temperature measurement B57540G1 Glass-encapsulated sensors G1540 Applications Temperature measurement Dimensional drawing Features Glass-encapsulated, heat-resistive and highly stable For temperature measurement up to 250 C Very short response time Small dimensions Leads: dumet wires (copper-clad FeNi) Options Leads: nickel-plated dumet wires Alternative dimensions available on request Dimensions in mm Approx. weight 20 mg Delivery mode Bulk General technical data Climatic category Max. power Resistance tolerance Rated temperature Dissipation factor Thermal cooling time constant Heat capacity (IEC 60068-1) (at 25 C) (in air) (in air) P25 RR/RR TR th c Cth 55/250/56 18 2, 3 25 approx. 0.4 approx. 3 approx. 1.3 mW % C mW/K s mJ/K Electrical specification and ordering codes R25 5k 10 k 10 k 50 k 100 k No. of R/T characteristic 8324 8307 7003 8342 8304 B25/85 K 3483 3478 3612 3991 4072 B0/100 K 3455 3450 3586 3967 4036 + = Resistance tolerance G = 2% H = 3% Please read Cautions and warnings and Important notes at the end of this document. Page 2 of 23 B25/100 K 3497 1% 3492 1% 3625 1% 4006 1% 4092 1% Ordering code B57540G1502+000 B57540G1103+000 B57540G1103+005 B57540G1503+000 B57540G1104+000 Temperature measurement B57540G1 Glass-encapsulated sensors G1540 Reliability data Test Standard Storage in dry heat IEC 60068-2-2 Storage in damp heat, steady state Rapid temperature cycling Test conditions Storage at upper category temperature T: 250 C t: 1000 h IEC Temperature of air: 85 C 60068-2-67 Relative humidity of air: 85% Duration: 1000 h IEC Lower test temperature: 55 C 60068-2-14 Upper test temperature: 200 C Number of cycles: 1000 Please read Cautions and warnings and Important notes at the end of this document. Page 3 of 23 R25/R25 (typical) < 3% Remarks < 2% No visible damage < 2% No visible damage No visible damage Temperature measurement B57540G1 Glass-encapsulated sensors G1540 Reliability data according to AEC-Q200, Rev. D Test Standard High temperature exposure (storage) Operational life MIL-STD-202, method 108 MIL-STD-202, method 108 Temperature cycling Terminal strength (leaded) Test conditions Storage at T = +125 C t = 1000 h 1000 h / +125 C Test voltage max. 0.3 V DC on NTC1) JESD 22, Lower test temperature: 55 C method JA-104 Upper test temperature: 125 C 1000 cycles Dwell time: max. 30 min at each temperature Transition time in air: max. 1 min MIL-STD-202, Test leaded device integrity method 211 Condition A: 2.27 N2) Mechanical shock MIL-STD-202, method 213, condition C Vibration MIL-STD-202, method 204 Acceleration: 40 g 2) Pulse duration: 6 ms Number of bumps: 3, each direction Acceleration: 5 g t = 20 min 12 cycles in each of 3 directions Frequency range: 10 ... 2000 Hz R25/R25 (typical) < 2% < 2% Remarks No visible damage No visible damage < 2% No visible damage < 1% No visible damage < 1% No visible damage < 1% No visible damage 1) Self heating of the NTC thermistor must not exceed 0.2 K, steady state. Test conditions deviating from AEC-Q200, Rev. D. 2) Deviating from AEC-Q200, Rev. D. Note Contact of NTC thermistors with any liquids and solvents shall be prevented. It must be ensured that no water enters the NTC thermistors (e.g. through plug terminals). Avoid dewing and condensation unless thermistor is specified for these conditions. Please read Cautions and warnings and Important notes at the end of this document. Page 4 of 23 Temperature measurement B57540G1 Glass-encapsulated sensors G1540 R/T characteristics R/T No. T (C) 7003 8304 B25/100 = 3625 K B25/100 = 4092 K RT/R25 (%/K) RT/R25 (%/K) 55.0 50.0 45.0 40.0 35.0 63.225 45.46 33.07 24.324 18.081 6.7 6.5 6.3 6.0 5.8 30.0 25.0 20.0 15.0 10.0 13.575 10.29 7.8716 6.0739 4.7258 5.6 5.4 5.3 5.1 4.9 18.275 13.443 9.9853 7.4867 5.6636 6.2 6.0 5.9 5.7 5.5 5.0 0.0 5.0 10.0 15.0 3.7062 2.9287 2.3311 1.8684 1.5075 4.8 4.6 4.5 4.4 4.2 4.3212 3.324 2.5769 2.0127 1.5834 5.3 5.2 5.0 4.9 4.7 20.0 25.0 30.0 35.0 40.0 1.224 1.0000 0.82176 0.67909 0.56422 4.1 4.0 3.9 3.8 3.7 1.2542 1.0000 0.80239 0.64776 0.52598 4.6 4.5 4.3 4.2 4.1 45.0 50.0 55.0 60.0 65.0 0.47122 0.3955 0.33355 0.2826 0.24049 3.6 3.5 3.4 3.3 3.2 0.4295 0.35262 0.291 0.24136 0.20114 4.0 3.9 3.8 3.7 3.6 70.0 75.0 80.0 85.0 90.0 0.20553 0.17637 0.15195 0.13141 0.11406 3.1 3.0 2.9 2.9 2.8 0.16841 0.14164 0.11963 0.10147 0.086407 3.5 3.4 3.3 3.3 3.2 95.0 100.0 105.0 110.0 115.0 0.099352 0.086837 0.076149 0.066989 0.059112 2.7 2.7 2.6 2.5 2.5 0.073867 0.063383 0.054584 0.04717 0.040901 3.1 3.0 3.0 2.9 2.8 120.0 125.0 130.0 135.0 140.0 0.052316 0.046433 0.041327 0.03688 0.032998 2.4 2.4 2.3 2.3 2.2 0.035581 0.03105 0.027179 0.023861 0.021008 2.8 2.7 2.6 2.6 2.5 145.0 150.0 155.0 0.029598 0.026612 0.023984 2.2 2.1 2.1 0.018548 0.016419 0.014573 2.5 2.4 2.4 Please read Cautions and warnings and Important notes at the end of this document. 100.11 69.56 48.945 34.853 25.102 7.4 7.2 6.9 6.7 6.5 Page 5 of 23 Temperature measurement B57540G1 Glass-encapsulated sensors R/T No. T (C) 160.0 165.0 7003 G1540 8304 B25/100 = 3625 K B25/100 = 4092 K RT/R25 (%/K) RT/R25 (%/K) 0.021665 2.0 0.012967 2.3 0.019613 2.0 0.011566 2.3 170.0 175.0 180.0 185.0 190.0 0.017793 0.016176 0.014735 0.013448 0.012297 1.9 1.9 1.8 1.8 1.8 0.010341 0.0092664 0.0083224 0.0074907 0.0067564 2.2 2.2 2.1 2.1 2.0 195.0 200.0 205.0 210.0 215.0 0.011265 0.010338 0.009504 0.0087516 0.0080718 1.7 1.7 1.7 1.6 1.6 0.0061064 0.0055299 0.0050175 0.0045611 0.0041537 2.0 2.0 1.9 1.9 1.9 220.0 225.0 230.0 235.0 240.0 0.0074567 0.0068989 0.0063925 0.0059318 0.005512 1.6 1.5 1.5 1.5 1.5 0.0037895 0.0034631 0.0031701 0.0029067 0.0026693 1.8 1.8 1.8 1.7 1.7 245.0 250.0 255.0 260.0 265.0 0.005129 0.004779 0.0044586 0.004165 0.0038955 1.4 1.4 1.4 1.4 1.3 0.0024551 0.0022615 0.0020862 0.0019273 0.0017829 1.7 1.6 1.6 1.6 1.5 270.0 275.0 280.0 285.0 290.0 0.0036478 0.0034199 0.0032098 0.003016 0.002837 1.3 1.3 1.3 1.2 1.2 0.0016516 0.0015319 0.0014228 0.0013231 0.0012319 1.5 1.5 1.5 1.4 1.4 295.0 300.0 0.0026714 0.002518 1.2 1.2 0.0011483 0.0010716 1.4 1.4 Please read Cautions and warnings and Important notes at the end of this document. Page 6 of 23 Temperature measurement B57540G1 Glass-encapsulated sensors G1540 R/T characteristics R/T No. T (C) 8307 8324 8342 B25/100 = 3492 K B25/100 = 3497 K B25/100 = 4006 K RT/R25 (%/K) RT/R25 (%/K) RT/R25 (%/K) 55.0 50.0 45.0 40.0 35.0 52.624 38.452 28.401 21.194 15.972 6.4 6.2 6.0 5.8 5.6 53.720 39.080 28.768 21.412 16.104 6.5 6.2 6.0 5.8 5.6 30.0 25.0 20.0 15.0 10.0 12.149 9.3246 7.2181 5.6332 4.4308 5.4 5.2 5.0 4.9 4.7 12.231 9.3758 7.2507 5.6542 4.4444 5.4 5.2 5.1 4.9 4.7 18.036 13.258 9.8478 7.3874 5.5937 6.3 6.1 5.8 5.7 5.5 5.0 0.0 5.0 10.0 15.0 3.5112 2.8024 2.252 1.8216 1.4827 4.6 4.4 4.3 4.2 4.1 3.5200 2.8080 2.2555 1.8236 1.4838 4.6 4.5 4.3 4.2 4.1 4.2733 3.2922 2.5567 2.0007 1.577 5.3 5.1 5.0 4.8 4.7 20.0 25.0 30.0 35.0 40.0 1.2142 1.0000 0.82818 0.68954 0.57703 3.9 3.8 3.7 3.6 3.5 1.2146 1.0000 0.82789 0.68906 0.57644 3.9 3.8 3.7 3.6 3.5 1.2516 1.0000 0.80501 0.65207 0.53135 4.5 4.4 4.3 4.2 4.0 45.0 50.0 55.0 60.0 65.0 0.48525 0.41 0.34798 0.29663 0.25392 3.4 3.3 3.2 3.2 3.1 0.48461 0.40933 0.34732 0.29599 0.25331 3.4 3.3 3.2 3.2 3.1 0.43546 0.35884 0.29726 0.24751 0.20709 3.9 3.8 3.7 3.6 3.5 70.0 75.0 80.0 85.0 90.0 0.21824 0.1883 0.16307 0.14174 0.12362 3.0 2.9 2.8 2.8 2.7 0.21767 0.18777 0.16259 0.14130 0.12323 3.0 2.9 2.8 2.8 2.7 0.17408 0.147 0.12468 0.10618 0.0908 3.4 3.3 3.3 3.2 3.1 95.0 100.0 105.0 110.0 115.0 0.10818 0.094973 0.08364 0.073881 0.06545 2.6 2.6 2.5 2.5 2.4 0.10783 0.094663 0.083368 0.073645 0.065247 2.6 2.6 2.5 2.5 2.4 0.077949 0.067168 0.058088 0.050412 0.043898 3.0 2.9 2.9 2.8 2.7 120.0 125.0 130.0 135.0 140.0 0.058144 0.051794 0.046259 0.04142 0.037179 2.3 2.3 2.2 2.2 2.1 0.057972 0.051649 0.046139 0.041323 0.037102 2.3 2.3 2.2 2.2 2.1 0.038351 0.033611 0.029546 0.02605 0.023033 2.7 2.6 2.5 2.5 2.4 145.0 150.0 155.0 0.033451 0.030166 0.027264 2.1 2.0 2.0 0.033393 0.030125 0.027238 2.1 2.0 2.0 0.020421 0.018154 0.016181 2.4 2.3 2.3 Please read Cautions and warnings and Important notes at the end of this document. Page 7 of 23 100.56 69.453 48.647 34.525 24.808 7.5 7.3 7.0 6.7 6.5 Temperature measurement B57540G1 Glass-encapsulated sensors R/T No. T (C) 160.0 165.0 8307 G1540 8324 8342 B25/100 = 3492 K B25/100 = 3497 K B25/100 = 4006 K RT/R25 (%/K) RT/R25 (%/K) RT/R25 (%/K) 0.024694 2.0 0.024669 1.9 0.014458 2.2 0.022414 1.9 0.022398 1.9 0.01295 2.2 170.0 175.0 180.0 185.0 190.0 0.020385 0.018577 0.016961 0.015514 0.014216 1.9 1.8 1.8 1.8 1.7 0.020383 0.018589 0.016987 0.015552 0.014263 1.9 1.8 1.8 1.7 1.7 0.011626 0.010462 0.0094347 0.0085267 0.0077222 2.1 2.1 2.0 2.0 2.0 195.0 200.0 205.0 210.0 215.0 0.013049 0.011999 0.011051 0.010194 0.0094181 1.7 1.7 1.6 1.6 1.6 0.013104 0.012060 0.011117 0.010264 0.0094930 1.7 1.6 1.6 1.6 1.5 0.0070076 0.0063716 0.0058044 0.0052974 0.0048434 1.9 1.9 1.8 1.8 1.8 220.0 225.0 230.0 235.0 240.0 0.0087144 0.0080751 0.0074933 0.0069631 0.0064791 1.5 1.5 1.5 1.5 1.4 0.0087939 0.0081599 0.0075842 0.0070611 0.0065853 1.5 1.5 1.4 1.4 1.4 0.004436 0.0040697 0.0037398 0.0034422 0.0031732 1.7 1.7 1.7 1.6 1.6 245.0 250.0 255.0 260.0 265.0 0.0060366 0.0056316 0.0052602 0.0049193 0.0046059 1.4 1.4 1.4 1.3 1.3 0.0061522 0.0057577 1.3 1.3 0.0029296 0.0027087 1.6 1.6 270.0 275.0 280.0 285.0 290.0 0.0043173 0.0040514 0.003806 0.0035793 0.0033696 1.3 1.3 1.2 1.2 1.2 295.0 300.0 0.0031753 0.0029952 1.2 1.2 Please read Cautions and warnings and Important notes at the end of this document. Page 8 of 23 Temperature measurement B57540G1 Glass-encapsulated sensors G1540 Mounting instructions 1 Soldering 1.1 Leaded NTC thermistors Leaded thermistors comply with the solderability requirements specified by CECC. When soldering, care must be taken that the NTC thermistors are not damaged by excessive heat. The following maximum temperatures, maximum time spans and minimum distances have to be observed: Dip soldering Iron soldering Bath temperature max. 260 C max. 360 C Soldering time max. 4 s max. 2 s Distance from thermistor min. 6 mm min. 6 mm Under more severe soldering conditions the resistance may change. 1.1.1 Wave soldering Temperature characteristic at component terminal with dual wave soldering 1.2 Leadless NTC thermistors In case of NTC thermistors without leads, soldering is restricted to devices which are provided with a solderable metallization. The temperature shock caused by the application of hot solder may produce fine cracks in the ceramic, resulting in changes in resistance. To prevent leaching of the metallization, solder with silver additives or with a low tin content Please read Cautions and warnings and Important notes at the end of this document. Page 9 of 23 Temperature measurement B57540G1 Glass-encapsulated sensors G1540 should be used. In addition, soldering methods should be employed which permit short soldering times. 1.3 SMD NTC thermistors SMD NTC thermistors can be provided with a nickel barrier termination or on special request with silver-palladium termination. The use of no-clean solder products is recommended. In any case mild, non-activated fluxes should be used. Flux residues after soldering should be minimized. SMD NTCs with AgPd termination are not approved for lead-free soldering. Nickel barrier termination Figure 1 SMD NTC thermistors, structure of nickel barrier termination The nickel barrier layer of the silver/nickel/tin termination (see figure 1) prevents leaching of the silver base metallization layer. This allows great flexibility in the selection of soldering parameters. The tin prevents the nickel layer from oxidizing and thus ensures better wetting by the solder. The nickel barrier termination is tested for all commonly-used soldering methods according to IEC 60068-2-58. Insufficient preheating may cause ceramic cracks. Rapid cooling by dipping in solvent is not recommended. The following test and process conditions apply for nickel barrier termination. Please read Cautions and warnings and Important notes at the end of this document. Page 10 of 23 Temperature measurement B57540G1 Glass-encapsulated sensors 1.3.1 G1540 Solderability (test to IEC 60068-2-58) Preconditioning: Immersion into flux F-SW 32. Evaluation criterion: Wetting of soldering areas 95%. Solder Bath temperature (C) Dwell time (s) SnPb 60/40 215 3 3 0.3 SnAg (3.0 ... 4.0), Cu (0.5 ... 0.9) 245 3 3 0.3 1.3.2 Resistance to soldering heat (test to IEC 60068-2-58) Preconditioning: Immersion into flux F-SW 32. Evaluation criterion: Leaching of side edges 1/3. Solder Bath temperature (C) Dwell time (s) SnPb 60/40 260 5 10 1 SnAg (3.0 ... 4.0), Cu (0.5 ... 0.9) 260 5 10 1 1.3.3 Reflow soldering Temperature ranges for reflow soldering acc. to IEC 60068-2-58 recommendations. Please read Cautions and warnings and Important notes at the end of this document. Page 11 of 23 Temperature measurement B57540G1 Glass-encapsulated sensors Profile feature Preheat and soak - Temperature min - Temperature max - Time G1540 Sn-Pb eutectic assembly Pb-free assembly Tsmin Tsmax tsmin to tsmax 100 C 150 C 60 ... 120 s 150 C 200 C 60 ... 120 s Average ramp-up rate Tsmax to Tp 3 C/ s max. 3 C/ s max. Liquidous temperature Time at liquidous TL tL 183 C 40 ... 150 s 217 C 40 ... 150 s Peak package body temperature Tp 215 C ... 260 C1) 235 C ... 260 C Time above (TP 5 C) tp 10 ... 40 s 10 ... 40 s Average ramp-down rate Tp to Tsmax 6 C/ s max. 6 C/ s max. max. 8 minutes max. 8 minutes Time 25 C to peak temperature 1) Depending on package thickness. Notes: All temperatures refer to topside of the package, measured on the package body surface. Number of reflow cycles: 3 Iron soldering should be avoided, hot air methods are recommended for repair purposes. Solder joint profiles for silver/nickel/tin terminations Please read Cautions and warnings and Important notes at the end of this document. Page 12 of 23 Temperature measurement B57540G1 Glass-encapsulated sensors 1.3.4 G1540 Recommended geometry of solder pads Recommended maximum dimensions (mm) Case size inch/mm A B C 0402/1005 0.6 0.6 1.7 0603/1608 1.0 1.0 3.0 0805/2012 1.3 1.2 3.4 1206/3216 1.8 1.2 4.5 2 Conductive adhesion An alternative to soldering for silver-palladium terminated components is the gluing of thermistors with conductive adhesives. The benefit of this method is that it involves no thermal stress. The adhesives used must be chemically inert. 3 Clamp contacting Pressure contacting by means of clamps is particularly suitable for applications involving frequent switching and high turn-on powers. 4 Robustness of terminations (leaded types) The leads meet the requirements of IEC 60068-2-21. They may not be bent closer than 4 mm from the solder joint on the thermistor body or from the point at which they leave the feedthroughs. During bending, any mechanical stress at the outlet of the leads must be removed. The bending radius should be at least 0.75 mm. Please read Cautions and warnings and Important notes at the end of this document. Page 13 of 23 Temperature measurement B57540G1 Glass-encapsulated sensors Tensile strength: G1540 Test Ua1: Value of applied force for Ua1 test: Diameter (d) of Force with tolerance of 10% corresponding round leads 0.25 mm 1.0 N 0.25 < 0.35 mm 2.5 N 0.35 < 0.50 mm 5.0 N 0.50 < 0.80 mm 10.0 N Bending strength: Test Ub: Two 90-bends in opposite directions Value of applied force for Ub test: Diameter (d) of Force with tolerance of 10% corresponding round leads 0.25 mm 0.5 N 0.25 < 0.35 mm 1.25 N 0.35 < 0.50 mm 2.5 N 0.50 < 0.80 mm 5N Torsional strength: Test Uc: severity 2 The lead is bent by 90 at a distance of 6 to 6.5 mm from the thermistor body. The bending radius of the leads should be approx. 0.75 mm. Two torsions of 180 each (severity 2). When subjecting leads to mechanical stress, the following should be observed: Tensile stress on leads During mounting and operation tensile forces on the leads are to be avoided. Bending of leads Bending of the leads directly on the thermistor body is not permissible. A lead may be bent at a minimum distance of twice the wire's diameter +4 mm from the solder joint on the thermistor body. During bending the wire must be mechanically relieved at its outlet. The bending radius should be at least 0.75 mm. Please read Cautions and warnings and Important notes at the end of this document. Page 14 of 23 Temperature measurement B57540G1 Glass-encapsulated sensors 5 G1540 Sealing and potting Sealing or potting processes can affect the reliability of the component. When thermistors are sealed, potted or overmolded, there must be no mechanical stress caused by thermal expansion during the production process (curing / overmolding process) and during later operation. The upper category temperature of the thermistor must not be exceeded. Ensure that the materials used (sealing / potting compound and plastic material) are chemically neutral. As thermistors are temperature sensitive components it should be considered that molding can affect the thermal surrounding and may influence e.g. the response time. Extensive testing is encouraged in order to determine whether overmolding or potting influences the functionality and/ or reliability of the component. 6 Cleaning Cleaning processes can affect the reliability of the component. If cleaning is necessary, mild cleaning agents are recommended. Cleaning agents based on water are not allowed. Washing processes may damage the product due to the possible static or cyclic mechanical loads (e.g. ultrasonic cleaning). They may cause cracks which might lead to reduced reliability and/ or lifetime. 7 Storage In order to maintain their solderability, thermistors must be stored in a non-corrosive atmosphere. Humidity, temperature and container materials are critical factors. Do not store SMDs where they are exposed to heat or direct sunlight. Otherwise, the packing material may be deformed or SMDs may stick together, causing problems during mounting. After opening the factory seals, such as polyvinyl-sealed packages, use the SMDs as soon as possible. The components should be left in the original packing. Touching the metallization of unsoldered thermistors may change their soldering properties. Storage temperature: 25 C up to 45 C Relative humidity (without condensation): 75% annual mean <95%, maximum 30 days per annum Solder the thermistors listed in this data book after shipment from EPCOS within the time specified: SMDs with AgPd termination: 6 months SMDs with nickel barrier termination: 12 months Leadless components: 12 months Leaded components: 24 months Please read Cautions and warnings and Important notes at the end of this document. Page 15 of 23 Temperature measurement B57540G1 Glass-encapsulated sensors 8 G1540 Placement and orientation of SMD NTC thermistors on PCB a) Component placement It is recommended that the PC board should be held by means of some adequate supporting pins such as shown left to prevent the SMDs from being damaged or cracked. b) Cracks When placing a component near an area which is apt to bend or a grid groove on the PC board, it is advisable to have both electrodes subjected to uniform stress, or to position the component's electrodes at right angles to the grid groove or bending line (see c) Component orientation). c) Component orientation Choose a mounting position that minimizes the stress imposed on the chip during flexing or bending of the board. Please read Cautions and warnings and Important notes at the end of this document. Page 16 of 23 Temperature measurement B57540G1 Glass-encapsulated sensors G1540 Cautions and warnings General See "Important notes" on page 2. Storage Store thermistors only in original packaging. Do not open the package prior to processing. Storage conditions in original packaging: storage temperature 25 C ... +45 C, relative humidity 75% annual mean, <95% maximum 30 days per annum, dew precipitation is inadmissible. Do not store thermistors where they are exposed to heat or direct sunlight. Otherwise, the packing material may be deformed or components may stick together, causing problems during mounting. Avoid contamination of thermistor surface during storage, handling and processing. Avoid storage of thermistors in harmful environments like corrosive gases (SOx, Cl etc). Use the components as soon as possible after opening the original packaging. Solder thermistors within the time specified after shipment from EPCOS. For leaded components this is 24 months, for SMD components with nickel barrier termination 12 months, for leadless components this is 12 months, for SMD components with AgPd termination 6 months. Handling NTC thermistors must not be dropped. Chip-offs or any other damage must not be caused during handling of NTCs. Do not touch components with bare hands. Gloves are recommended. Avoid contamination of thermistor surface during handling. Washing processes may damage the product due to the possible static or cyclic mechanical loads (e.g. ultrasonic cleaning). They may cause cracks to develop on the product and its parts, which might lead to reduced reliability or lifetime. Bending / twisting leads A lead (wire) may be bent at a minimum distance of twice the wire's diameter plus 4 mm from the component head or housing. When bending ensure the wire is mechanically relieved at the component head or housing. The bending radius should be at least 0.75 mm. Soldering Use resin-type flux or non-activated flux. Insufficient preheating may cause ceramic cracks. Rapid cooling by dipping in solvent is not recommended. Complete removal of flux is recommended. Please read Cautions and warnings and Important notes at the end of this document. Page 17 of 23 Temperature measurement B57540G1 Glass-encapsulated sensors G1540 Mounting Ensure that no thermo-mechanical stress occurs due to production processes (curing or overmolding processes) when thermistors are sealed, potted or overmolded or during their subsequent operation. The maximum temperature of the thermistor must not be exceeded. Ensure that the materials used (sealing/potting compound and plastic material) are chemically neutral. Electrodes/contacts must not be scratched or damaged before/during/after the mounting process. Contacts and housing used for assembly with the thermistor must be clean before mounting. Ensure that adjacent materials are designed for operation at temperatures comparable to the surface temperature of the thermistor. Be sure that surrounding parts and materials can withstand the temperature. Avoid contamination of the thermistor surface during processing. The connections of sensors (e.g. cable end, wire end, plug terminal) may only be exposed to an environment with normal atmospheric conditions. Tensile forces on cables or leads must be avoided during mounting and operation. Bending or twisting of cables or leads directly on the thermistor body is not permissible. Avoid using chemical substances as mounting aids. It must be ensured that no water or other liquids enter the NTC thermistors (e.g. through plug terminals). In particular, water based substances (e.g. soap suds) must not be used as mounting aids for sensors. The use of no-clean solder products is recommended. In any case mild, non-activated fluxes should be used. Flux residues after soldering should be minimized. Operation Use thermistors only within the specified operating temperature range. Use thermistors only within the specified power range. Environmental conditions must not harm the thermistors. Only use the thermistors under normal atmospheric conditions or within the specified conditions. Contact of NTC thermistors with any liquids and solvents shall be prevented. It must be ensured that no water enters the NTC thermistors (e.g. through plug terminals). For measurement purposes (checking the specified resistance vs. temperature), the component must not be immersed in water but in suitable liquids (e.g. perfluoropolyethers such as Galden). Avoid dewing and condensation unless thermistor is specified for these conditions. Bending or twisting of cables and/or wires is not permissible during operation of the sensor in the application. Be sure to provide an appropriate fail-safe function to prevent secondary product damage caused by malfunction. This listing does not claim to be complete, but merely reflects the experience of EPCOS AG. Display of ordering codes for EPCOS products The ordering code for one and the same EPCOS product can be represented differently in data Please read Cautions and warnings and Important notes at the end of this document. Page 18 of 23 Temperature measurement B57540G1 Glass-encapsulated sensors G1540 sheets, data books, other publications, on the EPCOS website, or in order-related documents such as shipping notes, order confirmations and product labels. The varying representations of the ordering codes are due to different processes employed and do not affect the specifications of the respective products. Detailed information can be found on the Internet under www.epcos.com/orderingcodes Please read Cautions and warnings and Important notes at the end of this document. Page 19 of 23 Temperature measurement B57540G1 Glass-encapsulated sensors G1540 Symbols and terms Symbol English German A AWG Area American Wire Gauge Flache Amerikanische Norm fur Drahtquerschnitte B B25/100 B value B value determined by resistance measurement at 25 C and 100 C B-Wert B-Wert, ermittelt durch Widerstandsmessungen bei 25 C und 100 C Cth Heat capacitance Warmekapazitat I Current Strom N Number (integer) Anzahl (ganzzahliger Wert) P25 Pdiss Pel Pmax Maximum power at 25 C Power dissipation Electrical power Maximum power within stated temperature range Maximale Leistung bei 25 C Verlustleistung Elektrische Leistung Maximale Leistung im angegebenenTemperaturbereich RB/RB Resistance tolerance caused by spread of B value Insulation resistance Parallel resistance Rated resistance Resistance tolerance Series resistance Resistance at temperature T (e.g. R25 = resistance at 25 C) Widerstandstoleranz, die durch die Streuung des B-Wertes verursacht wird Isolationswiderstand Parallelwiderstand Nennwiderstand Widerstandstoleranz Serienwiderstand Widerstand bei Temperatur T (z.B. R25 = Widerstand bei 25 C) T T t TA Tmax Temperature Temperature tolerance Time Ambient temperature Upper category temperature Tmin Lower category temperature Temperatur Temperaturtoleranz Zeit Umgebungstemperatur Obere Grenztemperatur (Kategorietemperatur) Untere Grenztemperatur (Kategorietemperatur) Top TR Tsurf Operating temperature Rated temperature Surface temperature Betriebstemperatur Nenntemperatur Oberflachentemperatur V Vins Vop Vtest Voltage Insulation test voltage Operating voltage Test voltage Spannung Isolationsprufspannung Betriebsspannung Prufspannung Rins RP RR RR/RR RS RT Please read Cautions and warnings and Important notes at the end of this document. Page 20 of 23 Temperature measurement B57540G1 Glass-encapsulated sensors G1540 Symbol English German Temperature coefficient Temperaturkoeffizient Tolerance, change Toleranz, Anderung th Dissipation factor Warmeleitwert c a Thermal cooling time constant Thermal time constant Thermische Abkuhlzeitkonstante Thermische Zeitkonstante Abbreviations / Notes Symbol English German Surface-mounted devices Oberflachenmontierbares Bauelement * To be replaced by a number in ordering Platzhalter fur Zahl im Bestellnummerncodes, type designations etc. code oder fur die Typenbezeichnung. + To be replaced by a letter. Platzhalter fur einen Buchstaben. All dimensions are given in mm. Alle Mae sind in mm angegeben. The commas used in numerical values denote decimal points. Verwendete Kommas in Zahlenwerten bezeichnen Dezimalpunkte. Please read Cautions and warnings and Important notes at the end of this document. Page 21 of 23 Important notes The following applies to all products named in this publication: 1. Some parts of this publication contain statements about the suitability of our products for certain areas of application. These statements are based on our knowledge of typical requirements that are often placed on our products in the areas of application concerned. We nevertheless expressly point out that such statements cannot be regarded as binding statements about the suitability of our products for a particular customer application. As a rule we are either unfamiliar with individual customer applications or less familiar with them than the customers themselves. For these reasons, it is always ultimately incumbent on the customer to check and decide whether a product with the properties described in the product specification is suitable for use in a particular customer application. 2. We also point out that in individual cases, a malfunction of electronic components or failure before the end of their usual service life cannot be completely ruled out in the current state of the art, even if they are operated as specified. In customer applications requiring a very high level of operational safety and especially in customer applications in which the malfunction or failure of an electronic component could endanger human life or health (e.g. in accident prevention or life-saving systems), it must therefore be ensured by means of suitable design of the customer application or other action taken by the customer (e.g. installation of protective circuitry or redundancy) that no injury or damage is sustained by third parties in the event of malfunction or failure of an electronic component. 3. The warnings, cautions and product-specific notes must be observed. 4. In order to satisfy certain technical requirements, some of the products described in this publication may contain substances subject to restrictions in certain jurisdictions (e.g. because they are classed as hazardous). Useful information on this will be found in our Material Data Sheets on the Internet (www.tdk-electronics.tdk.com/material). Should you have any more detailed questions, please contact our sales offices. 5. We constantly strive to improve our products. Consequently, the products described in this publication may change from time to time. The same is true of the corresponding product specifications. Please check therefore to what extent product descriptions and specifications contained in this publication are still applicable before or when you place an order. We also reserve the right to discontinue production and delivery of products. Consequently, we cannot guarantee that all products named in this publication will always be available. The aforementioned does not apply in the case of individual agreements deviating from the foregoing for customer-specific products. 6. Unless otherwise agreed in individual contracts, all orders are subject to our General Terms and Conditions of Supply. 7. Our manufacturing sites serving the automotive business apply the IATF 16949 standard. The IATF certifications confirm our compliance with requirements regarding the quality management system in the automotive industry. Referring to customer requirements and customer specific requirements ("CSR") TDK always has and will continue to have the policy of respecting individual agreements. Even if IATF 16949 may appear to support the acceptance of unilateral requirements, we hereby like to emphasize that only requirements mutually agreed upon can and will be implemented in our Quality Management System. For clarification purposes we like to point out that obligations from IATF 16949 shall only become legally binding if individually agreed upon. Page 22 of 23 Important notes 8. The trade names EPCOS, CeraCharge, CeraDiode, CeraLink, CeraPad, CeraPlas, CSMP, CTVS, DeltaCap, DigiSiMic, ExoCore, FilterCap, FormFit, LeaXield, MiniBlue, MiniCell, MKD, MKK, MotorCap, PCC, PhaseCap, PhaseCube, PhaseMod, PhiCap, PowerHap, PQSine, PQvar, SIFERRIT, SIFI, SIKOREL, SilverCap, SIMDAD, SiMic, SIMID, SineFormer, SIOV, ThermoFuse, WindCap are trademarks registered or pending in Europe and in other countries. Further information will be found on the Internet at www.tdk-electronics.tdk.com/trademarks. Release 2018-10 Page 23 of 23