WF2K, WF08K, WF06K, WF04K ±.0%, 0.5%, ±0.25%, ±0.% TC50 High Precision Thick Film chip resistors Size 206, 0805, 0603, 0402 Page of 8 WFxxK_V02 Jan.200
FEATURE. 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. Consctruction of Chip-R WFxxK Page 2 of 8 WFxxK_V02 Jan.200
QUICK REFERENCE DATA Item General Specification Series No. WF2K WF08K WF06K WF04K Size code 206 ( 326 ) 0805 ( 202 ) 0603 ( 608 ) 0402 ( 005 ) Resistance Tolerance ±.0%, ±0.5%, ±0.25%, ±0.% Resistance Range TCR (ppm/ C) 0Ω ~ MΩ ( E24 +E96 ) ± 50 ppm/ C 00Ω ~ MΩ ( E24 +E96 ) Max. dissipation at T amb=70 C /4W /8W /0W /6W Max. Operation Voltage (DC or RMS) 200V 50V 50V 50V Max. Overload Voltage (DC or RMS) 400V 300V 00V 00V Climatic category 55/25/56 Note :. This is the maximum voltage that may be continuously supplied to the resistor element, see IEC publication 605-8 2. Max. Operation Voltage : So called RCWV (Rated Continuous Working Voltage) is determined by RCWV = Rated Power Resistance Value or Max. RCWV listed above, whichever is lower. DIMENSIONS(unit : mm) Type WF2K WF08K WF06K WF04K L 3.0 ± 0.0 2.00 ± 0.0.60 ± 0.0.00 ± 0.05 W.60 ± 0.0.25 ± 0.0 0.80 ± 0.0 0.50 ± 0.05 A 0.50 ± 0.20 0.40 ± 0.20 0.30 ± 0.0 0.20 ± 0.0 B 0.45 ± 0.20 0.40 ± 0.20 0.30 ± 0.5 0.25 ± 0.0 t 0.60 ± 0.5 0.50 ± 0.5 0.45 ± 0.0 0.35 ± 0.05 Protective coat t B A End termination Resistive layer W T 00 Ceramic Substrate L Page 3 of 8 WFxxK_V02 Jan.200
MARKING 3-digits marking for 0603 size WFxxK has same marking rule as commodity ±%. 3-digits marking(±% : 0603) Nominal resistance.e-24 series As 0603 WR06X ±5%. 2.E-96 series Description The st two digit codes are referring to the CODE on the table, the 3rd code is the index of resistance value : Y=0-2,X=0 -,A=0 0,B=0,C=0 2,D=0 3,E=0 4,F=0 5 EX : 7.8Ω=25X,78Ω=25A,K78 =25B 7K8=25C, 78K=25D, M78=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 CODE R_Value CODE R_value CODE R_value CODE R_value CODE R_value CODE R_value 0 00 3 33 25 78 37 237 49 36 6 422 73 562 85 750 02 02 4 37 26 82 38 243 50 324 62 432 74 576 86 768 03 05 5 40 27 87 39 249 5 332 63 442 75 590 87 787 04 07 6 43 28 9 40 255 52 340 64 453 76 604 88 806 05 0 7 47 29 96 4 26 53 348 65 464 77 69 89 825 06 3 8 50 30 200 42 267 54 357 66 475 78 634 90 845 07 5 9 54 3 205 43 274 55 365 67 487 79 649 9 866 08 8 20 58 32 20 44 280 56 374 68 499 80 665 92 887 09 2 2 62 33 25 45 287 57 383 69 5 8 68 93 909 0 24 22 65 34 22 46 294 58 392 70 523 82 698 94 93 27 23 69 35 226 47 30 59 402 7 536 83 75 95 953 2 30 24 74 36 232 48 309 60 42 72 549 84 732 96 976 4-digits marking for 206, 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 97Ω6 the R is used as a digit. For values of 00Ω or greater, the first 3 digits are significant, the fourth digit indicates the number of multiple to follow. Example RESISTANCE 0Ω 2Ω 00Ω 6800Ω 47000Ω 4-digits marking 0R0 2R0 000 680 4702 No marking code for 0402 size Page 4 of 8 WFxxK_V02 Jan.200
FUNCTIONAL DESCRIPTION Product characterization Standard values of nominal resistance are taken from the E24 & E96 series for resistors with a tolerance of ±.0%, ±0.5%, ±0.25%, ±0.%. 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.200
SOLDERING CONDITION The robust construction of chip resistors allows them to be completely immersed in a solder bath of 260 C for 0 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 235 C during 2 seconds within lead-free solder bath. The test condition for no leaching is 260 C 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. Size code WF08 K xxxx D T L WF2: 206 WF08: 0805 WF06: 0603 WF04: 0402 Type code TCR 50ppm Resistance code E24 +E92: R is first code followed by 3 significant digits. E24: 39R0=>39R0 820R =>8200 E96: 49R9 =>49R9 499R =>4990. Reeled tape packaging: 8mm width paper taping. 5,000pcs/reel for WF2, WF08, WF06; 0,000pcs/reel for WF04. Tolerance F : ±.0% D : ±0.5% C: ±0.25% B : ±0.% Packaging code T : Reeled Termination code L : lead free Page 6 of 8 WFxxK_V02 Jan.200
TEST AND REQUIREMENTS(JIS C 520- : 998) TEST DC resistance Clause 4.5 Temperature Coefficient of Resistance(T.C.R) Clause 4.8 Short time overload (S.T.O.L) Clause 4.3 Resistance to soldering heat(r.s.h) Clause 4.8 Solderability Clause 4.7 Temperature cycling Clause 4.9 Load life (endurance) Clause 4.25 Load life in Humidity Clause 4.24 Bending strength Clause 4.33 Adhision Clause 4.32 Insulation Resistance Clause 4.6 Dielectric Withstand Voltage PROCEDURE DC resistance values measured <0Ω@0.V, <00Ω@0.3V, <KΩ@.0V, <0KΩ@3V, <00KΩ@0V,<MΩ@25V, <0MΩ@30V Natural resistance change per change in degree centigrade. R R R 2 6 0 ( t t ) 2 (ppm/ C) R : Resistance at reference temperature R 2 : Resistance at test temperature t : 20 C+5 C- C Permanent resistance change after a 5second application of a voltage 2.5 times RCWV or the maximum overload voltage specified in the above list, whichever is less. Un-mounted chips completely immersed for 0±second in a SAC solder bath at 260 ±5ºC Un-mounted chips completely immersed for 2±0.5 second in a SAC solder bath at 235 ±5 30 minutes at -55 C±3 C, 2~3 minutes at 20 C+5 C- C, 30 minutes at +25 C±3 C, 2~3 minutes at 20 C+5 C- C, total 5 continuous cycles 70±2ºC, 000 hours, loaded with RCWV or Vmax,.5 hours on and 0.5 hours off 000 hours, at rated continuous working voltage in humidity chamber controller at 40 C±2 C and 90~95% relative humidity,.5hours on and 0.5 hours off Resistors mounted on a 90mm glass epoxy resin PCB(FR4); bending : 3 mm, once for 0 seconds. Pressurizing force: 5N, Test time: 0±sec. Apply the maximum overload voltage (DC) for minute Apply the maximum overload voltage (AC) for minute REQUIREMENT Resistor Within the specified tolerance Refer to QUICK REFERENCE DATA R/R max. ±(0.5%+0.05Ω) no visible damage R/R max. ±(0.5%+0.05Ω) good tinning (>95% covered) no visible damage no visible damage R/R max. ±(0.5%+0.05Ω) R/R max. ±(.0%+0.05Ω) R/R max. ±(.0%+0.05Ω) R/R max. ±(0.5%+0.05Ω) No remarkable damage or removal of the terminations. R 0GΩ No breakdown or flashover Clause 4.7 Page 7 of 8 WFxxK_V02 Jan.200
PACKAGING Paper Tape specifications (unit :mm) F P0 D Series No. A B W D E WF2 3.60±0.20 2.00±0.20 8.00±0.30 3.50±0.20.75±0.0 WF08 2.40±0.20.65±0.20 8.00±0.30 3.50±0.20.75±0.0 WF06.90±0.20.0±0.20 8.00±0.30 3.50±0.20.75±0.0 WF04.20±0.0 0.7±0.0 8.00±0.20 3.50±0.05.75±0.0 Series No. F P0 ΦD T WF2 4.00±0.0 4.00±0.0 0. Φ.50 + 0. 0 Max..0 WF08 4.00±0.0 4.00±0.0 0. Φ.50 + 0. 0 Max..0 WF06 4.00±0.0 4.00±0.0 0. Φ.50 + 0. 0 0.65±0.05 WF04 2.00±0.0 4.00±0.0 + 0. Φ.50 0. 0 0.40±0.05 Reel dimensions C B A D Symbol A B C D (unit : mm) Φ78.0±2.0 Φ60.0±.0 3.0±0.2 9.0±0.5 Taping quantity - Chip resistors 5,000 pcs per reel ( WF2, WF08, WF06 ) - Chip resistors 0,000 pcs per reel ( WF04 ) Page 8 of 8 WFxxK_V02 Jan.200