Approval sheet WF25U, WF20U, WF10U, 1%, 0.5%, 0.25%, 0.1%, 0.05% TC25 High Precision Thin Film Chip Resistors Size 2512, 2010, 1210 *Contents in this sheet are subject to change without prior notice. Page 1 of 7 ASC_WF25_20_10U_V02 Nov.2011 Approval sheet FEATURE 1. SMD metal film resistor 2. High reliability and stability of 0.5% and below per customer request 3. High performance of TCR: 25 ppm/K and below per customer request 4. Low current noise 5. +/-0.05% is upon the customer request. 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. Construction of Chip-R WFxxU Page 2 of 7 ASC_WF25_20_10U_V02 Nov.2011 Approval sheet QUICK REFERENCE DATA Item General Specification Series No. WF25U WF20U WF10U Size code 2512 ( 6432 ) 2010 ( 5025 ) 1210 ( 3225 ) 1%, 0.5%, 0.25%, 0.1%, 0.05% Resistance Tolerance Resistance Range 10 ~ 1M ( E24 +E192 ) TCR (ppm/C) 10 ~ 1M ( E24 +E192 ) 10 ~ 1M ( E24 +E192 ) +25 ~ -25 ppm/C Max. dissipation at Tamb=70C 3/4W 1/2W 1/4W Max. Operation Voltage (DC or RMS) 200V 200V 200V Max. Overload Voltage (DC or RMS) 400V 400V 400V Operation temperature - 55~ +155'C 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. 3. 1M to 2 M of WF10U is upon the customer request. 4. 1M to 3 M of WF25U and WF20U is upon the customer request DIMENSIONS:( unit:mm) Type WF25U WF20U WF10U L 6.35 0.10 5.00 0.10 3.10 0.10 W 3.20 0.15 2.50 0.15 2.60 0.15 A 0.60 0.20 0.60 0.20 0.50 0.20 B 0.50 0.20 0.50 0.20 0.50 0.20 t 0.55 0.10 0.55 0.10 0.55 0.10 Protective coat t End termination B Resistive layer A Ceramic Substrate W T 1001 L Page 3 of 7 ASC_WF25_20_10U_V02 Nov.2011 Approval sheet MARKING 4-digits marking for 2512, 2010, 1210 size For E24/E96 series, each resistor is marked with a four digits code on the protective coating to designate the nominal resistance value. For non E24/E96 series, no marking is applied! Example RESISTANCE 10 12 100 6800 47000 4-digits marking 10R0 12R0 1000 6801 4702 FUNCTIONAL DESCRIPTION Product characterization Standard values of nominal resistance are taken from the E24/E192 series for resistors with a tolerance of 1%, 0.5%, 0.25%, 0.1%, 0.05%. The values of the E24/E192 series are in accordance with "IEC publication 60063". Derating The power that the resistor can dissipate depends on the operating temperature; see Fig.2 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 4 of 7 ASC_WF25_20_10U_V02 Nov.2011 Approval sheet 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 . WF25 U xxxx D T L Size code Type code Resistance code Tolerance Packaging code Termination code WF25: 2512 U: TCR 25ppm E192+E24: F : 1.0% T : Reeled L = Sn base (lead free) WF20: 2010 WF10: 1210 3 significant digits followed by no. of zeros D : 0.5% C: 0.25% 102 =1020 37.4K =3742 B : 0.1% 220 =2200 A : 0.05% 1. Reeled tape packaging: 8mm width paper taping for WF10U, 12mm width plastic taping for WF25U, WF20U 4,000pcs/reel for WF25U, WF20U; 5,000pcs/reel for WF10U Page 5 of 7 ASC_WF25_20_10U_V02 Nov.2011 Approval sheet TEST AND REQUIREMENTS (JIS C 5201-1 : 1998) TEST PROCEDURE REQUIREMENT Resistor DC resistance DC resistance values measured at the test voltages specified below : 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 centigrade. R2 - R1 x 106 R1 (t2 - t1 ) Refer to "QUICK REFERENCE DATA" (ppm/C) R1 : Resistance at reference temperature R2 : Resistance at test temperature t1 : 20C+5C-1C t2 : 125C+5C-1C or -55C+5C-1C Short time overload (S.T.O.L) Clause 4.13 Resistance to soldering heat(R.S.H) Clause 4.18 Solderability Clause 4.17 Temperature cycling Permanent resistance change after a 5second application of a voltage R/R max. (0.5%+0.05) 2.5 times RCWV or the maximum overload voltage specified in the above list, whichever is less. Un-mounted chips completely immersed for 101second in a SAC no visible damage solder bath at 2605C R/R max. (0.1%+0.05) Un-mounted chips completely immersed for 20.5 second in a SAC good tinning (>95% covered) solder bath at 2355 no visible damage no visible damage Clause 4.19 30 minutes at -55C3C, 2~3 minutes at 20C+5C-1C, 30 minutes at +155C3C, 2~3 minutes at 20C+5C-1C, total 5 continuous cycles Load life (endurance) 1000 +48/-0 hours, loaded with RCWV or Vmax in chamber controller R/R max. (0.5%+0.05) 702C, 1.5 hours on and 0.5 hours off Clause 4.25 Load life in Humidity Clause 4.24 R/R max. (0.25%+0.05) 1000 +48/-0 hours, loaded with RCWV or Vmax in humidity chamber R/R max. (0.5%+0.05) 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 PCB(FR4); R/R max. (0.1%+0.05) bending : 3 mm, once for 10 seconds. Adhesion Pressurizing force: 5N, Test time: 101sec. Clause 4.32 Insulation Resistance No remarkable damage or removal of the terminations. Apply the maximum overload voltage (DC) for 1minute R10G Clause 4.6 Dielectric Withstand Apply the maximum overload voltage (AC) for 1 minute No breakdown or flashover Bending strength Voltage Clause 4.7 Page 6 of 7 ASC_WF25_20_10U_V02 Nov.2011 Approval sheet PACKAGING Paper Tape specifications (unit :mm) Series No. A B W F E WF25 6.900.20 3.600.20 12.000.30 5.500.10 1.750.10 WF20 5.500.20 2.800.20 12.000.30 5.500.10 1.750.10 WF10 3.600.20 3.000.20 8.000.30 3.500.20 1.750.10 Series No. P1 P0 D T WF25 4.000.10 4.000.10 1.50 +-00..10 MAX1.2 WF20 4.000.10 4.000.10 1.50 +-00..10 MAX1.2 WF10 4.000.10 4.000.10 1.50 +-00..10 Max. 1.0 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 4,000 pcs per reel ( WF25U, WF20U ) - Chip resistors 5,000 pcs per reel ( WF10U ) Page 7 of 7 ASC_WF25_20_10U_V02 Nov.2011