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Page 1 of 7 ASC_WKxxS_J_AUTO_V02 OCT 2015 WK25S WK20S WK10S WK12S W K08S WK06S Thick Film Power Surge Chip Resistors AEC Q -200 Qualified Size 2512, 2010, 1210, 1206 , 0805, 0603 *Contents in this sheet are subject to change without prior notice.

Page 2 of 7 ASC_WKxxS_J_AUTO_V02 OCT 2015 FEATURE 1. Power rating and compact size 2. High reliability and stability 3. Reduced size of final equipment 4. High anti-surge protection 5. Halogen free 6. Automotive grade AEC Q-200 qualified APPLICATION

  • Power supply
  • Measurement instrument
  • Automotive industry
  • Medical or Military equipment

DESCRIPTION

The resistors are constructed in a high grade ceramic body (aluminum oxide). Internal electrodes are added at each end and connected by a resistive paste that is applied to the top surface of the substrate. The composition of the paste is adjusted to request resistance to nominal value within tolerance which controlled by printing process in this resistive layer. The resistive layer is covered with a protective coat. Finally, the two external end terminations are added. For ease of soldering the outer layer of these end terminations is a Tin (Pb free) alloy. Fig 1. Construction of Chip-R WKxxS

Page 3 of 7 ASC_WKxxS_J_AUTO_V02 OCT 2015 QUICK REFERENCE DATA Item General Specification Series No. WK25S WK20S WK10S WK12S WK08S WK06S Size code 2512(6432 ) 2010 (5025) 1210 (3225) 1206 ( 3216 ) 0805 (2012) 0603 (1608) Resistance Tolerance ±5% ±10% ±20% (E24) Resistance Range 0.27 Ω ~ 22MΩ 1 Ω ~ 1MΩ TCR (ppm/ °C) 1.1M Ω ~ 22M Ω 1Ω ~ 1M Ω 0.27 Ω ~ 0.91 Ω ± 200 ppm /°C ± 100 ppm /°C ± 200 ppm /°C 10 - 1M Ω : ± 100 ppm 1 - 9.1 Ω : ± 200 ppm Max. dissipation at T amb =70 °C

1 W 3/4W 1/2W 1/3W 1/4W 1/4W

Max. Operation Voltage 200V 200V 200V 200V 150V 150V Max. Overload Voltage 400V 400V 400V 400V 300V 300V 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 Value Resistance Power Rated RCWV ×= or Max. RCWV listed above, whichever is lower. MECHANICAL DATA(unit : mm) Symbol WK25S WK20S WK10S WK12S WK08S WK06S 1 0 1

Page 4 of 7 ASC_WKxxS_J_AUTO_V02 OCT 2015 MARKING 1. Each resistor is marked with a three-digit code on the protective coating to designate the nominal resistance value. Single pulse limiting power chart De-rating curve The power that the resistor can dissipate depends on the operating temperature; see Fig.2

Page 5 of 7 ASC_WKxxS_J_AUTO_V02 OCT 2015 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. SOLDERING CONDITION The robust construction of chip resistors allows them to be completely immersed in a solder bath of 260 °C 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 235°C during 2 seconds. 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. Fig 3. Infrared soldering profile for Chip Resistors CATALOGUE NUMBERS The resistors have a catalogue number starting with . WK12 S 472_ J T L J Size code WK25 : 2512 WK20 : 2010 WK10 : 1210 WK12 : 1206 WK08 : 0805 WK06 : 0603 Type code S : surge Resistance code E24 : 3 significant digits followed by no. of zeros and a blank 472 = 4K7 Tolerance J: ±5% ±10% M: ±20% Packaging code T : 7” Reeled taping Termination code L = Sn base (lead free) Special code J = Automotive grade AEC Q200 Compliant Taping quantity - 1210, 1206, 0805, 0603 Chip resistors 5,000 pcs paper tape per reel. - 2512, 2010 Chip resistors 4,000 pcs PC tape per reel.

Page 6 of 7 ASC_WKxxS_J_AUTO_V02 OCT 2015 TEST AND REQUIREMENTS(JIS C 5201-1 : 1998) TEST PROCEDURE REQUIREMENT Temperature Coefficient of Resistance(T.C.R) Clause 4.8 Natural resistance change per change in degree centigrade. ( ) 12 1 12 10 ×− ttR RR (ppm/ °C) t 1 : 20° C+5° C-1° C R 1 : Resistance at reference temperature R 2 : Resistance at test temperature Refer to “QUICK REFERENCE DATA” Short time overload (S.T.O.L) Clause 4.13 Permanent resistance change after a 2 second application of a voltage 2.5 times RCWV or the maximum overload voltage specified in the above list, whichever is less. ΔR/R max. ±(1%+0.05 Ω ) no visible damage Resistance to soldering heat(R.S.H) AEC Q200-15 Un-mounted chips completely immersed for 10 ±1second in a solder bath at 260℃±5ºC no visible damage Δ R/R max. ±(1%+0.05 Ω ) Solderability AEC Q200-18 Baked 155’C x 4hrs/ Un-mounted chips completely immersed for 2±0.5second in a solder bath at 235℃±5 ℃ good tinning (>95% covered) no visible damage Temperature cycling AEC Q200-4 30 minutes at -55 °C ±3°C, 2~3 minutes at 20° C+5° C-1° C, 30 minutes at +155 °C ±3°C, 2~3 minutes at 20° C+5° C-1° C, total 1000 cycles no visible damage ΔR/R max. ±(1%+0.05 Ω ) Operational Life MIL-STD-202 method 108 1000+48/-0 hours; 35% of operation power, 125 ±2°C ΔR/R max. ±(3%+0.1 Ω ) no visible damage Bias Humidity AEC Q200-7 1000 hours, at 10% rated continuous power in humidity chamber controller at 85 °C ±2°C and 85% relative humidity, ΔR/R max. ±(3%+0.1 Ω ) no visible damage High temperature exposure AEC Q200-3 155 ºC, no load, 1000hours ΔR/R max. ±(3%+0.1 Ω ) no visible damage Bending strength CAEC Q200-21 Resistors mounted on a 90mm glass epoxy resin PCB(FR4); bending : 2 mm, once for 10 seconds ΔR/R max. ±(1%+0.05 Ω ) Adhesion AEC Q200-22 Pressurizing force: 20N, Test time: 60±1sec. No remarkable damage or removal of the terminations Insulation Resistance Clause 4.6 Apply the maximum overload voltage (DC) for 1minute R ≧1G Ω Dielectric Withstand Voltage Clause 4.7 Apply the maximum overload voltage (AC) for 1 minute No breakdown or flashover

Page 7 of 7 ASC_WKxxS_J_AUTO_V02 OCT 2015 PACKAGING Tape specifications (unit :mm) Series No. A B W F E WK25S 6.90 ±0.20 3.60 ±0.20 WK20S 5.50 ±0.20 3.100 ±0.20 WK12S 3.60 ±0.20 2.00 ±0.15 WK08S 2.50±0.20 1.65 ±0.15 Series No. P1 P0 Φ D T WK25S WK20S 1.1±0.15 WK10S 1.0±0.20 WK12S Max. 1.0 WK08S Max. 1.0 WK06S 0 . 050 . 1+ Φ Max. 0.8 Reel dimensions Reel / Tape A B C D Taping quantity - 1210, 1206, 0805, 0603 Chip resistors 5,000 pcs paper tape per reel. - 2010, 2512 Chip resistors 4,000 pcs plastic tape per reel.