Approval sheet WF25P, WF20P, WF12P 1%, 5% 1 ~ 1M Thick Film High Power Chip Resistors Size 2512 2W, 2010 1W, 1206 1/2W *Contents in this sheet are subject to change without prior notice. Page 1 of 7 ASC_WF25-20-12P_V10 Jul.2011 Approval sheet FEATURE 1. 2. 3. 4. 5. High power rating and compact size High reliability and stability Reduced size of final equipment RoHS compliant and Lead free products Flame Retardant 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. Finally, the two external end terminations are added. For ease of soldering the outer layer of these end terminations is a Tin (lead free) alloy. Fig 1. Construction of Chip-R Page 2 of 7 ASC_WF25-20-12P_V10 Jul.2011 Approval sheet QUICK REFERENCE DATA Item General Specification Series No. WF25P WF20P WF12P Size code 2512 (6432) 2010 (5025) 1206 (3216) 1%, 5% Resistance Tolerance Resistance Range 0,1 ~ 1M 100 TCR (ppm/C) Max. dissipation at Tamb=70C 2W 1W 1/2 W Max. Operation Voltage (DC or RMS) 300V 200V 200V Max. Overload Voltage (DC or RMS) 500V 400V 400V Climatic category (IEC 60068) 55/155/56 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. 2 3. 2W loading with total solder-pad and trace size of 300 mm 4. 0 maximum resistance Rmax < 20m TEST CONDITION FOR JUMPER (0 ) Item WF25P WF20P WF12P Power Rating At 70C 2W 1W 1/2W Resistance Max. 20m Rated Current 10A 7A 5A Peak Current 25A 17.5A 12.5A Operating Temperature -55 ~ +155C MECHANICAL DATA Unit: mm 102 Page 3 of 7 Symbol WF25P WF20P WF12P L 6.30 0.20 5.00 0.20 3.10 0.15 W 3.10 0.20 2.50 0.20 1.60 0.15 T 0.60 0.15 0.60 0.10 0.55 0.10 Tt 0.60 0.25 0.60 0.25 0.50 0.25 Tb 1.80 0.25 0.60 0.25 0.50 0.25 ASC_WF25-20-12P_V10 Jul.2011 Approval sheet Recommended Solder Pad Dimensions D Type WF25P W W 3.7mm D 2.45mm L 7.6mm L MARKING Each resistor is marked with a four-digit (WF25P;WF20P,WF12P 1%) and three-digit (WF25P,WF20P,WF12P 5%) code on the protective coating to designate the nominal resistance value. Example: 102 = 1k 16R0 = 16 16R0 102 FUNCTIONAL DESCRIPTION Product characterization Standard values of nominal resistance are taken from the E96 & E24 series for resistors with a tolerance of 5% & 1%. The values of the E24/E96 series are in accordance with "IEC publication 60063". Derating curve The power that the resistor can dissipate depends on the operating temperature; see Fig.2 Figure 2 Page 4 of 7 Maximum dissipation in percentage of rated power as a function of the ambient temperature ASC_WF25-20-12P_V10 Jul.2011 Approval sheet 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 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. 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. Fig 3. Infrared soldering profile for Chip Resistors CATALOGUE NUMBERS The resistors have a catalogue number starting with . WF25 P 102 J Size code Type code Resistance code Tolerance WF25 : 2512 P :Power WF20 : 2010 2512 size=2 watt F : 1% WF12 : 1206 2010 size=1 watt 5% E24: 2 significant digits followed by No. of zeros e.g.: 1206 size=0.5 watt 1% digits 3ohm =3R0 10ohm =100 J : 5% P : Jumper T L Packaging code Termination code T : 7" Reel taping L = Sn base (lead free) 56Kohm =563 E24+E96:3 significant followed by No. of zeros Tape packaging =1000 =3742 WF12 : 8mm width paper taping 5,000pcs per reel. WF25WF20: Page 5 of 7 100 37.4K 12mm width plastic taping 4,000pcs per reel. ASC_WF25-20-12P_V10 Jul.2011 Approval sheet TEST AND REQUIREMENTS Basic specification : JIS C 5201-1 : 1998 TEST Clause 4.8 Temperature Coefficient of Resistance (TCR ) PROCEDURE REQUIREMENT Natural resistance change per change in degree Refer to quick reference data for T.C.R centigrade. specification R2 - R1 x 106 R1 (t2 - t1 ) (ppm/C) R1 : Resistance at reference temperature R2 : Resistance at test temperature t1 : 20C+5C-1C Clause 4.13 Short time overload Clause 4.18 Resistance to soldering heat 5.0x Rated power or Max. Overload Voltage Measure resistance after 30 minutes.. for 5 sec. R/R max. J: (2%+0.1) F: (1%+0.05) Un-mounted chips completely immersed for 101second No visible damage in a SAC solder bath at 2605C R/R max. J: (1%+0.1) F: (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 4.18 Leach Test Un-mounted chips completely immersed for 601second Ditto in a solder bath at 2605 Clause 4.19 30 minutes at -55C3C, 2~3 minutes at 20C+5C-1 C, No visible damage 30 minutes at +155C3C, 2~3 minutes at R/R max. J (1%+0.1) 20C+5C-1C, total 5 continuous cycles F (0.5%+0.05) Clause 4.17 Temperature cycling Clause 4.25 Load life (endurance) Clause 4.24 Load life in Humidity 1000 +48/-0 hours, loaded with RCWV or Vmax in No visible damage chamber controller 702C, 1.5 hours on and 0.5 hours R/R max. J (3%+0.1) off F (1%+0.05) 1000 +48/-0 hours, loaded with RCWV or Vmax in No visible damage humidity chamber controller at 40C2C and 90~95% R/R max. J (3%+0.1) relative humidity, 1.5hours on and 0.5 hours off F (1%+0.05) Bending strength Resistors mounted on a 90mm glass epoxy resin No visible damage PCB(FR4); bending : 2 mm(2512;2010) 3mm(1206), R/R max. J (1%+0.1) once for 10 seconds F (0.5%+0.05) Clause 4.32 Pressurizing force: 5N, Test time: 101sec No remarkable damage or removal of the terminations Apply the maximum overload voltage (DC) for 1minute R10G Apply the maximum overload voltage (AC) for 1 minute No breakdown or flashover Clause 4.33 Adhesion Insulation Resistance Clause 4.6 Dielectric Withstand Voltage Clause 4.7 Page 6 of 7 ASC_WF25-20-12P_V10 Jul.2011 Approval sheet PACKAGING Paper Tape(WF12P) & Plastic Tape(WF25P;WF20P) specifications Series No. A B WF25P 6.900.20 3.600.20 WF20P 5.500.20 2.800.20 WF12P 3.600.20 Series No. (unit :mm) W F E 12.000.30 5.500.10 1.750.10 2.000.20 8.000.30 3.500.20 1.750.10 P1 P0 D T 4.000.10 1.50 +-00..10 Max. 1.2 4.000.10 WF25P WF20P WF12P Max. 1.0 Reel dimensions (unit : mm) Reel / Tape A B C 7" reel for 12mm tape 12.41.0 178.02.0 60.01.0 7" reel for 8mm tape Page 7 of 7 D 13.00.2 9.00.5 ASC_WF25-20-12P_V10 Jul.2011