WF12K, WF08K, WF06K, WF04K 1.0%, 0.5%, 0.25%, 0.1% TC50 High Precision Thick Film chip resistors Size 1206, 0805, 0603, 0402 Page 1 of 8 WFxxK_V02 Jan.2010 00-S-R45 FEATURE 1. SMD Thick film resistor 2. High reliability and stability 3. High performance of TCR: 50 ppm/K 4. High precision 5. RoHS compliant & Lead free APPLICATION * Medical equipment * Measuring instrument * Communication device * Computer * Printer DESCRIPTION The resistors are constructed in a high grade ceramic body (aluminum oxide). Internal metal electrodes are added at each end and connected by a resistive layer that is applied to the top surface of the substrate. The composition of the resistive layer is adjusted to give the approximate resistance required and the value is trimmed to nominated value within tolerance which controlled by laser trimming of this resistive layer. The resistive layer is covered with a protective coat. Finally, the two external end terminations are added. For environmental soldering issue, the outer layer of these end terminations is a Lead-free solder . Fig 1. Consctruction of Chip-R WFxxK Page 2 of 8 WFxxK_V02 Jan.2010 00-S-R45 QUICK REFERENCE DATA Item General Specification Series No. WF12K WF08K WF06K WF04K Size code 1206 ( 3216 ) 0805 ( 2012 ) 0603 ( 1608 ) 0402 ( 1005 ) Resistance Tolerance 1.0%, 0.5%, 0.25%, 0.1% Resistance Range 10 ~ 1M ( E24 +E96 ) 100 ~ 1M ( E24 +E96 ) 50 ppm/C TCR (ppm/C) Max. dissipation at Tamb=70C 1/4W 1/8W 1/10W 1/16W Max. Operation Voltage (DC or RMS) 200V 150V 50V 50V Max. Overload Voltage (DC or RMS) 400V 300V 100V 100V Climatic category 55/125/56 Note : 1. This is the maximum voltage that may be continuously supplied to the resistor element, see "IEC publication 60115-8" 2. Max. Operation Voltage : So called RCWV (Rated Continuous Working Voltage) is determined by RCWV = Rated Power x Resistance Value or Max. RCWV listed above, whichever is lower. DIMENSIONS(unit : mm) Type WF12K WF08K WF06K WF04K L 3.10 0.10 2.00 0.10 1.60 0.10 1.00 0.05 W 1.60 0.10 1.25 0.10 0.80 0.10 0.50 0.05 A 0.50 0.20 0.40 0.20 0.30 0.10 0.20 0.10 B 0.45 0.20 0.40 0.20 0.30 0.15 0.25 0.10 t 0.60 0.15 0.50 0.15 0.45 0.10 0.35 0.05 Protective coat t End termination B Resistive layer A Ceramic Substrate W T 1001 L Page 3 of 8 WFxxK_V02 Jan.2010 00-S-R45 MARKING 3-digits marking for 0603 size WFxxK has same marking rule as commodity 1%. 3-digits marking1% : 0603 Nominal resistance Description 1.E-24 series As 0603 WR06X 5%. 2.E-96 series The 1st two digit codes are referring to the CODE on the table, the 3rd code is the index of resistance value : Y=10-2X=10-1A=100B=101C=102D=103E=104F=105 EX : 17.8=25X178=25A1K78 =25B 17K8=25C 178K=25D 1M78=25E 3. Remark There is no marking for the items are not under E-24 and E-96 series CODE R_value CODE R_value R_value CODE R_value CODE R_value CODE R_value CODE R_value 01 100 13 133 25 178 37 237 49 316 61 422 73 562 85 750 02 102 14 137 26 182 38 243 50 324 62 432 74 576 86 768 03 105 15 140 27 187 39 249 51 332 63 442 75 590 87 787 04 107 16 143 28 191 40 255 52 340 64 453 76 604 88 806 05 110 17 147 29 196 41 261 53 348 65 464 77 619 89 825 06 113 18 150 30 200 42 267 54 357 66 475 78 634 90 845 07 115 19 154 31 205 43 274 55 365 67 487 79 649 91 866 08 118 20 158 32 210 44 280 56 374 68 499 80 665 92 887 09 121 21 162 33 215 45 287 57 383 69 511 81 681 93 909 10 124 22 165 34 221 46 294 58 392 70 523 82 698 94 931 11 127 23 169 35 226 47 301 59 402 71 536 83 715 95 953 12 130 24 174 36 232 48 309 60 412 72 549 84 732 96 976 CODE R_Value CODE 4-digits marking for 1206, 0805 size Each resistor is marked with a four digits code on the protective coating to designate the nominal resistance value of E24+E96. For values below 976 the R is used as a digit. For values of 100 or greater, the first 3 digits are significant, the fourth digit indicates the number of multiple to follow. Example RESISTANCE 10 12 100 6800 47000 4-digits marking 10R0 12R0 1000 6801 4702 No marking code for 0402 size Page 4 of 8 WFxxK_V02 Jan.2010 00-S-R45 FUNCTIONAL DESCRIPTION Product characterization Standard values of nominal resistance are taken from the E24 & E96 series for resistors with a tolerance of 1.0%, 0.5%, 0.25%, 0.1%. The values of the E24/E96 series are in accordance with "IEC publication 60063". Derating The power that the resistor can dissipate depends on the operating temperature; see Fig.2 Figure 2. Maximum dissipation in percentage of rated power As a function of the ambient temperature MOUNTING Due to their rectangular shapes and small tolerances, Surface Mountable Resistors are suitable for handling by automatic placement systems. Chip placement can be on ceramic substrates and printed-circuit boards (PCBs). Electrical connection to the circuit is by individual soldering condition. The end terminations guarantee a reliable contact. Page 5 of 8 WFxxK_V02 Jan.2010 00-S-R45 SOLDERING CONDITION The robust construction of chip resistors allows them to be completely immersed in a solder bath of 260C for 10 seconds. Therefore, it is possible to mount Surface Mount Resistors on one side of a PCB and other discrete components on the reverse (mixed PCBs). Surface Mount Resistors are tested for solderability at 235C during 2 seconds within lead-free solder bath. The test condition for no leaching is 260C for 30 seconds. Typical examples of soldering processes that provide reliable joints without any damage are given in Fig 3. CATALOGUE NUMBERS The resistors have a catalogue number starting with . WF08 K xxxx D Size code Type code Resistance code Tolerance WF12: 1206 TCR 50ppm E24 +E192: F : 1.0% WF08: 0805 R is first code followed by D : 0.5% WF06: 0603 3 significant digits. C: 0.25% WF04: 0402 E24: 39R0=>39R0 T L Packaging code Termination code T : Reeled L : lead free B : 0.1% 820R =>8200 E96: 49R9 =>49R9 499R =>4990 1. Reeled tape packaging: 8mm width paper taping. 5,000pcs/reel for WF12, WF08, WF06; 10,000pcs/reel for WF04. Page 6 of 8 WFxxK_V02 Jan.2010 00-S-R45 TEST AND REQUIREMENTS(JIS C 5201-1 : 1998) TEST REQUIREMENT PROCEDURE Resistor DC resistance DC resistance values measured Clause 4.5 <10@0.1V, Within the specified tolerance <100@0.3V, <1K@1.0V, <10K@3V, <100K@10V,<1M@25V, <10M@30V Temperature Coefficient of Resistance(T.C.R) Clause 4.8 Natural resistance change per change in degree Refer to "QUICK REFERENCE DATA" centigrade. R2 - R1 x 106 R1 (t2 - t1 ) (ppm/C) R1 : Resistance at reference temperature R2 : Resistance at test temperature t1 : 20C+5C-1C Short time overload (S.T.O.L) Clause 4.13 Permanent resistance change after a 5second R/R max. (0.5%+0.05) application of a voltage 2.5 times RCWV or the maximum overload voltage specified in the above list, whichever is less. Resistance to soldering heat(R.S.H) Clause 4.18 Un-mounted chips completely immersed for no visible damage 101second in a SAC solder bath at 2605C R/R max. (0.5%+0.05) Solderability Un-mounted chips completely immersed for 20.5 good tinning (>95% covered) second in a SAC solder bath at 2355 no visible damage Clause 4.17 Temperature cycling Clause 4.19 Load life (endurance) Clause 4.25 Load life in Humidity Clause 4.24 30 minutes at -55C3C, 2~3 minutes at no visible damage 20C+5C-1C, 30 minutes at +125 C3C, R/R max. (0.5%+0.05) 2~3 minutes at 20C+5C-1C, total 5 continuous cycles 702C, 1000 hours, loaded with RCWV or R/R max. (1.0%+0.05) Vmax,1.5 hours on and 0.5 hours off 1000 hours, at rated continuous working voltage in R/R max. (1.0%+0.05) humidity chamber controller at 40C2C and 90~95% relative humidity, 1.5hours on and 0.5 hours off Clause 4.33 Resistors mounted on a 90mm glass epoxy resin R/R max. (0.5%+0.05) PCB(FR4); bending : 3 mm, once for 10 seconds. Adhision Pressurizing force: 5N, Test time: 101sec. Bending strength Clause 4.32 Insulation Resistance Clause 4.6 Dielectric Withstand Voltage No remarkable damage or removal of the terminations. Apply the maximum overload voltage (DC) for R10G 1minute Apply the maximum overload voltage (AC) for 1 No breakdown or flashover minute Clause 4.7 Page 7 of 8 WFxxK_V02 Jan.2010 00-S-R45 PACKAGING Paper Tape specifications (unit :mm) P0 F D Series No. A B W D E WF12 3.600.20 2.000.20 8.000.30 3.500.20 1.750.10 WF08 2.400.20 1.650.20 8.000.30 3.500.20 1.750.10 WF06 1.900.20 1.100.20 8.000.30 3.500.20 1.750.10 WF04 1.200.10 0.70.10 8.000.20 3.500.05 1.750.10 Series No. F P0 D T WF12 4.000.10 4.000.10 1.50 +-00..10 Max. 1.0 WF08 4.000.10 4.000.10 1.50 +-00..10 Max. 1.0 WF06 4.000.10 4.000.10 1.50 +-00..10 0.650.05 WF04 2.000.10 4.000.10 1.50 +-00..10 0.400.05 Reel dimensions B C A D Symbol A B C D (unit : mm) 178.02.0 60.01.0 13.00.2 9.00.5 Taping quantity - Chip resistors 5,000 pcs per reel ( WF12, WF08, WF06 ) - Chip resistors 10,000 pcs per reel ( WF04 ) Page 8 of 8 WFxxK_V02 Jan.2010 00-S-R45