WR18X_TR WALSIN | Alldatasheet
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Page 1 of 7 WR18-20-25X_TR_V01 Jul- 2014 WR18X(W), WR20X(W), WR25X(W) Thick Film Power Chip Resistors RoHS compliant lead content <100ppm Size 1218,2010,2512 *Contents in this sheet are subject to change without prior notice.
Page 2 of 7 WR18-20-25X_TR_V01 Jul- 2014 FEATURE 1. High power rating and compact size 2. High reliability and stability 3. Reduced size of final equipment 4. RoHS exemption free & Lead free products APPLICATION
- Power supply
- PDA
- Digital meter
- Computer
- Automotives
- Battery charger
- DC-DC power converter
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 paste that is applied to the top surface of the substrate. The composition of the paste 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. For all sizes overcoat color is light blue. Finally, the two external end terminations are added. For ease of soldering the outer layer of these end terminations is Tin (lead free) alloy. Fig 1. Construction of Chip-R
Page 3 of 7 WR18-20-25X_TR_V01 Jul- 2014 QUICK REFERENCE DATA Item General Specification Series No. WR18X(W) WR20X(W) WR25X(W) Size code 1218(3248) 2010 ( 5025 ), 2512(6432) Resistance Tolerance ±5% (E24); ±1% (E24+E96) Resistance Range 1Ω ~ 10M Ω , Jumper (0 Ω ) ± 100 ppm/ °C ± 100 ppm/ °C ± 100 ppm/ °C TCR (ppm/ °C) : 10 Ω < Rn ≤ 10MΩ 1Ω≤ Rn ≤ 10Ω ± 200 ppm/ °C ± 200 ppm/ °C ± 200 ppm/ °C Max. dissipation at T amb =70 °C 1W 0.5 W 1W Max. Operation Voltage (DC or RMS) 200V 200V 250V Max. Overload Voltage (DC or RMS) 400V 400V 500V Climatic category (IEC 60068) 55/155/56 Test conditions for jumper ( 0 ohm ) Type WR18X(W) WR20X(W) WR25X(W) Power Rating At 70C 1 W 1/2 W 1 W Resistance Max. 50mR Max. 50mR Max. 50mR Rated Current 4.5 A 3.2 A 4.5 A Peak Current 11 A 8 A 11 A Operating Temperature -55C ~ 155C -55C ~ 155C -55C ~ 155C 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) TYPE WR18X(W) WR20X(W) WR25X(W)
±5% & ±1%. The values of the E24/E96 series are in accordance with “IEC publication 60063”. Figure 3. Maximum dissipation in percentage of rated power as a function of the ambient temperature. 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 7 WR18-20-25X_TR_V01 Jul- 2014 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 4. Fig 4. Infrared soldering profile for Chip Resistors CATALOGUE NUMBERS The resistors have a catalogue number starting with . WR20 X 472_ J T R Size code WR25 : 2512 WR20 : 2010 WR18: 1218 Type code X : ±5%: 1 Ω -10M Ω ±1%: 10 Ω -1M Ω W : 1% : <10 Ω or >1M Ω Resistance code 5% E24 : 2 significant digits followed by no. of zeros and a blank 4.7 Ω =4R7_ 10 Ω =100_ 1% E24+E96 : 3 significant digits followed by no. of zeros 102 Ω =1020 37.4K Ω =3742 Tolerance J : ±5% F : ±1% P : Jumper Packaging code T : 7” Reel taping (T:1218 10” Reel) RoHS code R = Lead content < 100ppm
Page 6 of 7 WR18-20-25X_TR_V01 Jul- 2014 TEST AND REQUIREMENTS(JIS C 5201-1 : 1998) Essentially all tests are carried out according to the schedule of IEC publication 115-8, category LCT /UCT /56 (rated temperature range : Lower C ategory Temperature, U pper C ategory Temperature; damp heat, long term, 56 days). The testing also meets the requirements specified by EIA, EIAJ and JIS. The tests are carried out in accordance with IEC publication 68, "Recommended basic climatic and mechanical robustness testing procedure for electronic components" and under standard atmospheric conditions according to IEC 60068-1, subclause 5.3. Unless otherwise specified, the following value supplied : Temperature: 15 °C to 35 °C. Relative humidity: 45% to 75%. Air pressure: 86kPa to 106 kPa (860 mbar to 1060 mbar). All soldering tests are performed with midly activated flux. TEST PROCEDURE REQUIREMENT DC resistance Clause 4.5 DC resistance values measured at the test voltages specified below : <100K Ω @10V, <1M Ω @25V, <10M Ω @30V Within the specified tolerance 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 Clause 4.13 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. ΔR/R max. ±(2%+0.1 Ω ) Resistance to soldering heat(R.S.H) Clause 4.18 Un-mounted chips completely immersed for 10 ±1second in a SAC solder bath at 260 ℃±5ºC no visible damage Δ R/R max. ±(1% +0.05 Ω ) Solderability Clause 4.17 Un-mounted chips completely immersed for 2±0.5 second in a SAC solder bath at 235℃±5 ℃ good tinning (>95% covered) no visible damage Temperature cycling Clause 4.19 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 5 continuous cycles no visible damage ΔR/R max. ±(1% +0.05 Ω ) Load life (endurance) Clause 4.25 1000 +48/-0 hours, loaded with RCWV or Vmax in chamber controller 70 ±2ºC, 1.5 hours on and 0.5 hours off ΔR/R max. ±(3% +0.1 Ω ) Load life in Humidity Clause 4.24 1000 +48/-0 hours, loaded with RCWV or Vmax in humidity chamber controller at 40 °C ±2°C and 90~95% relative humidity, 1.5hours on and 0.5 hours off ΔR/R max. ±(3% +0.1 Ω ) Bending strength Clause 4.33 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 Clause 4.32 Pressurizing force: 5N, Test time: 10 ±1sec. No remarkable damage or removal of the terminations Insulation Resistance Clause 4.6 Apply the maximum overload voltage (DC) for 1minute R ≧10G Ω Dielectric Withstand Voltage Clause 4.7 Apply the maximum overload voltage (AC) for 1 minute No breakdown or flashover
Page 7 of 7 WR18-20-25X_TR_V01 Jul- 2014 PACKAGING Plastic Tape specifications (unit :mm) Type A B W F E WR18 4.90 ±0.20 3.55 ±0.30 WR20 5.50 ±0.20 2.80 ±0.20 WR25 6.90 ±0.20 3.60 ±0.20 Type P1 P0 Φ D T WR18 8.00 ±0.10 1.30 ±0.20 WR20 WR25 4.00 ±0.10 4.00 ±0.10 1 . 0 0 . 050 . 1+ Φ MAX1.2 Reel dimensions Symbol A B C D Taping quantity WR20, WR25 by plastic tape taping 4,000 pcs per reel. WR18 by plastic tape taping 3,000 pcs per reel