NTC Thermistors for automotive devices (chip type) Multilayer NTC Thermistors Series: ERTJ Features ● Surface Mount Device (0402, 0603) ● Highly reliable multilayer / monolithic structure ● Wide temperature operating range (–40 to 150 ● Environmentally-friendly lead-free ● RoHS compliant °C) Recommended Applications ● For ● For ● For ● For ● For ● For car audio system ECUs electric pumps and compressors LED lights batteries temperature detection of various circuits Explanation of Part Numbers 1 2 3 4 5 6 7 8 9 10 11 12 E R T J 0 E G 1 0 3 F M Common Code Product Code Type Code ERT NTC J Chip Type (SMD) Thermistors Multilayer Type Size Code 0 “0402” 1 “0603” Packaging Style Code E V “0402” Pressed Carrier Taping Punched Carrier Taping (Pitch : 2 mm) “0603” Punched Carrier Taping (Pitch : 4 mm) B Value Class Code 2701 to 2800 A 3301 to 3400 G 3801 to 3900 M 4001 to 4100 P 4201 to 4300 R 4301 to 4400 S 4401 to 4500 T 4601 to 4700 V Nominal Resistance R25 (Ω) The first two digits are significant figures of resistance and the third one denotes the number of zeros following them. (Example) Resistance Tolerance Code G ±1% Narrow Tolerance ±2% Type H J ±3% Standard ±5% Type F M Automotive component Construction 3 4 5 1 2 No. Name A Semiconductive Ceramics B Internal electrode C D E Terminal electrode Substrate electrode Intermediate electrode External electrode Design and specifications are each subject to change without notice. Ask factory for the current technical specifications before purchase and/or use. Should a safety concern arise regarding this product, please be sure to contact us immediately. 00 Jun. 2015 NTC Thermistors for automotive devices (chip type) Ratings Size code (EIA) Operating Temperature Range Rated Maximum Power Dissipation✽1 Dissipation Factor✽2 0(0402) 1(0603) –40 to 150 °C 66 mW Approximately 2 mW/°C 100 mW Approximately 3 mW/°C ✽1 Rated Maximum Power Dissipation : The maximum power that can be continuously applied at the rated ambient temperature. · The maximum value of power, and rated power is same under the condition of ambient temperature 25 °C or less. If the temperature exceeds 25 °C, rated power depends on the decreased power dissipation curve. · Please see “Operating Power” for details. ✽2 Dissipation factor : The constant amount power required to raise the temperature of the Thermistor 1 °C through self heat generation under stable temperatures. · Dissipation factor is the reference value when mounted on a glass epoxy board (1.6 mmT). Part Number List ● 0402(EIA) Part Number ERTJ0EG103□M ERTJ0EP473□M ERTJ0ER104□M ERTJ0EV104□M ● 0603(EIA) Nominal Resistance at 25 °C 10 kΩ 47 kΩ 100 kΩ 100 kΩ B Value B Value at 25/50(K) at 25/85(K) 3380 K±1 % 3435 K±1 % 4050 K±1 % (4100 K) 4250 K±1 % (4300 K) 4700 K±1 % (4750 K) Nominal Resistance at 25 °C ERTJ1VG103□M 10 kΩ ERTJ1VP473□M 47 kΩ ERTJ1VV104□M 100 kΩ Part Number B Value B Value at 25/50(K) at 25/85(K) 3380 K±1 % 3435 K±1 % 4100 K±1 % (4150 K) 4700 K±1 % (4750 K) □ : Resistance Tolerance Code (F : ±1%, G : ±2%, H : ±3%, J : ±5%) □ : Resistance Tolerance Code (F : ±1%, G : ±2%, H : ±3%, J : ±5%) ● Temperature B25/50 B25/85 T(°C) -40 -35 -30 -25 -20 -15 -10 -5 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 105 110 115 120 125 B25/50= and Resistance value (the resistance value at 25 °C is set to 1)/ Reference values ERTJ□□G~ (3380 K) 3435 K ERTJ□□P~ 4050 K (4100 K) ERTJ□□P~ 4100 K (4150 K) ERTJ□□R~ 4250 K (4300 K) ERTJ□□V~ 4700 K (4750 K) 20.52 15.48 11.79 9.069 7.037 5.507 4.344 3.453 2.764 2.227 1.806 1.474 1.211 1 0.8309 0.6941 0.5828 0.4916 0.4165 0.3543 0.3027 0.2595 0.2233 0.1929 0.1672 0.1451 0.1261 0.1097 0.09563 0.08357 0.07317 0.06421 0.05650 0.04986 33.10 24.03 17.63 13.06 9.761 7.362 5.599 4.291 3.312 2.574 2.013 1.584 1.255 1 0.8016 0.6461 0.5235 0.4266 0.3496 0.2881 0.2386 0.1985 0.1659 0.1393 0.1174 0.09937 0.08442 0.07200 0.06166 0.05306 0.04587 0.03979 0.03460 0.03013 34.56 24.99 18.26 13.48 10.04 7.546 5.720 4.369 3.362 2.604 2.030 1.593 1.258 1 0.7994 0.6426 0.5194 0.4222 0.3451 0.2837 0.2344 0.1946 0.1623 0.1359 0.1143 0.09658 0.08189 0.06969 0.05957 0.05117 0.04415 0.03823 0.03319 0.02886 42.40 29.96 21.42 15.50 11.33 8.370 6.244 4.699 3.565 2.725 2.098 1.627 1.271 1 0.7923 0.6318 0.5069 0.4090 0.3320 0.2709 0.2222 0.1831 0.1516 0.1261 0.1054 0.08843 0.07457 0.06316 0.05371 0.04585 0.03929 0.03378 0.02913 0.02519 59.76 41.10 28.61 20.14 14.33 10.31 7.482 5.481 4.050 3.015 2.262 1.710 1.303 1 0.7734 0.6023 0.4721 0.3723 0.2954 0.2356 0.1889 0.1523 0.1236 0.1009 0.08284 0.06834 0.05662 0.04712 0.03939 0.03308 0.02791 0.02364 0.02009 0.01712 kn (R25/R50) 1/298.15–1/323.15 B25/85= kn (R25/R85) 1/298.15–1/358.15 R25=Resistance at 25.0±0.1 °C R50=Resistance at 50.0±0.1 °C R85=Resistance at 85.0±0.1 °C Design and specifications are each subject to change without notice. Ask factory for the current technical specifications before purchase and/or use. Should a safety concern arise regarding this product, please be sure to contact us immediately. 00 Jun. 2015 NTC Thermistors for automotive devices (chip type) Specification and Test Method Item Specification Rated Zero-power Within the specified tolerance. Resistance (R25) Test Method The value is measured at a power that the influence of self-heat generation can be negligible (0.1mW or less), at the rated ambient temperature of 25.0±0.1°C. B Value The Zero-power resistances; R1 and R2, shall be measured respectively at T1 (deg.C) and T2 (deg.C). The B value is calculated by the following equation. Shown in each Individual Specification. ✽ Individual Specification shall specify B25/50 or B25/85. BT1/T2= T1 25.0 ±0.1 °C 25.0 ±0.1 °C B25/50 B25/85 Adhesion kn (R1)–kn (R2) 1/(T1+273.15)–1/(T2+273.15) T2 50.0 ±0.1 °C 85.0 ±0.1 °C The terminal electrode shall be free from peeling Applied force : or signs of peeling. Size 0402, 0603 : 5 N Duration : 10 s Size : 0402 1.0 0.5 0.5R Test Sample Board 1.0 Size : 0603 Test Sample Bending distance : 2 mm Bending speed : 1 mm/s 20 R340 45±2 Bending distance Bending Strength There shall be no cracks and other mechanical damage. R25 change : within ±5 % Unit : mm 45±2 Unit : mm Resistance to Vibration There shall be no cracks and other mechanical damage. R25 change : B Value change : Resistance to Impact within ±2 % within ±1 % There shall be no cracks and other mechanical damage. R25 change : B Value change : within ±2 % within ±1 % Solder samples on a testing substrate, then apply vibration to them. Acceleration :5G Vibrational frequency : 10 to 2000 Hz Sweep time : 20 minutes 12 cycles in three directions, which are perpendicular to each other Solder samples on a testing substrate, then apply impacts to them. Pulse waveform : Semisinusoidal wave, 11 ms Impact acceleration : 50 G Impact direction : X-X', Y-Y', Z-Z' In 6 directions, three times each Design and specifications are each subject to change without notice. Ask factory for the current technical specifications before purchase and/or use. Should a safety concern arise regarding this product, please be sure to contact us immediately. 00 Jun. 2015 NTC Thermistors for automotive devices (chip type) Specification and Test Method Item Resistance to Soldering Heat Specification There shall be no cracks and other mechanical damage. R25 change : B Value change : within ±2 % within ±1 % Test Method Soldering bath method Solder temperature : 260 ±5 °C, 270 ±5 °C Dipping period : 3.0 ±0.5 s, 10.0 ±0.5 s Preheat condition : Step 1 2 Temp (°C) 80 to 100 150 to 200 Period (s) 120 to 180 120 to 180 Solderability More than 95 % of the soldered area of both terminal electrodes shall be covered with fresh solder. Soldering bath method Solder temperature : 230 ±5 °C Dipping period : 4 ±1 s Solder : Sn-3.0Ag-0.5Cu Temperature Cycling R25 change : B Value change : within ±2 % within ±1 % Conditions of one cycle Step 1 : –55±3 °C, 30±3 min. Step 2 : Room temp., 3 min. max. Step 3 : 125±5 °C, 30±3 min. Step 4 : Room temp., 3 min. max. Number of cycles: 2000 cycles Humidity R25 change : B Value change : within ±2 % within ±1 % Temperature : 85 ±2 °C Relative humidity : 85 ±5 % Test period : 2000 +48/0 h Biased Humidity R25 change : B Value change : within ±2 % within ±1 % Temperature : 85 ±2 °C Relative humidity : 85 ±5 % Applied power : 10 mW(D.C.) Test period : 2000 +48/0 h Low Temperature Exposure R25 change : B Value change : within ±2 % within ±1 % Temperature Test period : –40 ±3 °C : 2000 +48/0 h High Temperature R25 change : Exposure 1 B Value change : within ±2 % within ±1 % Temperature Test period : 125 ±3 °C : 2000 +48/0 h High Temperature R25 change : Exposure 2 B Value change : within ±3 % within ±2 % Temperature Test period : 150 ±3 °C : 1000 +48/0 h Design and specifications are each subject to change without notice. Ask factory for the current technical specifications before purchase and/or use. Should a safety concern arise regarding this product, please be sure to contact us immediately. 00 Jun. 2015 NTC Thermistors for automotive devices (chip type) Dimensions in mm (not to scale) L W (Unit : mm) Size Code (EIA) L W T L1, L2 0 (0402) 1.0±0.1 0.50±0.05 0.50±0.05 0.25±0.15 1 (0603) 1.60±0.15 0.8±0.1 0.8±0.1 0.3±0.2 T L2 L1 Packaging Methods Size Code ● Reel Packing Quantities Thickness (mm) 0 (0402) 0.5 1 (0603) 0.8 for Taping Pitch Quantity (mm) (pcs./reel) Kind of Taping Punched Carrier Taping 2 10,000 4 4,000 W1 E C B ● Standard D ● Pitch W2 2 mm (Punched Carrier Taping) : Size 0402 A Feeding hole fD0 t1 Chip pocket E Symbol (mm) fB fA 180 0 –3 60.0 +1.0 0 C D E 13.0±0.5 21.0±0.8 2.0±0.5 W1 9.0 +1.0 0 W2 11.4±1.0 B F W A Dim. t2 Chip component A Symbol B W P1 P2 F E P0 P1 P2 Tape running direction P0 fD 0 t1 Dim. 0.62 1.12 8.0 3.50 1.75 2.00 2.00 4.0 1.5+0.1 0.7 (mm) ±0.05 ±0.05 ±0.2 ±0.05 ±0.10 ±0.05 ±0.05 ±0.1 ● Pitch 0 t2 Feeding hole fD0 Part and Taped End Leader part Top cover tape 1.0 max. max. 4 mm (Punched Carrier Taping) : Size 0603 100 min. Vacant position 400 min. Chip pocket Taped end E t1 ● Leader B F W A t2 Symbol 160 min. Vacant position (Unit : mm) ERTJ0 (0402) Minimum Quantity/ Packing Unit 10,000 Packing Quantity in Carton 200,000 Carton L×W×H (mm) 250×200×200 ERTJ1 (0603) 4,000 80,000 250×200×200 A Dim. 1.0 (mm) P1 Chip component ±0.1 B 1.8 ±0.1 W F E P2 Tape running direction P0 P1 P2 P0 fD 0 t1 t2 8.0 3.50 1.75 4.0 2.00 4.0 1.5+0.1 1.1 1.4 ±0.2 ±0.05 ±0.10 ±0.1 ±0.05 ±0.1 0 max. max. Minimum Quantity / Packing Unit Part Number (Size) Part No., quantity and country of origin are designated on outer packages in English. Design and specifications are each subject to change without notice. Ask factory for the current technical specifications before purchase and/or use. Should a safety concern arise regarding this product, please be sure to contact us immediately. 00 Jun. 2015 NTC Thermistors for automotive devices (chip type) Multilayer NTC Thermistors Series: ERTJ Handling Precautions Safety Precautions The NTC Thermistors for automotive devices (chip type), hereafter referred to as Thermisotrs, is designed for use in automotive devices. When subjected to severe electrical, environmental, and/or mechanical stress beyond the specifications, as noted in the Ratings and Specified Conditions section, the Thermistors’ performance may be degraded, or become failure mode, such as short circuit mode and open-circuit mode. If you use under the condition of short-circuit, heat generation of thermistors will occur by running large current due to application of voltage. There are possibilities of smoke emission, substrate burn-out, and, in the worst case, fire. For products which require higher safety levels, please carefully consider how a single malfunction can affect your product. In order to ensure the safety in the case of a single malfunction, please design products with fail-safe, such as setting up protecting circuits, etc. ● For the following applications and conditions, please contact us for product of special specification not found in this document. · When your application may have difficulty complying with the safety or handling precautions specified below. · High-quality and high-reliability required devices that have possibility of causing hazardous conditions, such as death or injury (regardless of directly or indirectly), due to failure or malfunction of the product. 1 Aircraft and Aerospace Equipment (artificial satellite, rocket, etc.) 2 Submarine Equipment (submarine repeating equipment, etc.) 3 Transportation Equipment (airplanes, trains, ship, traffic signal controllers, etc.) 4 Power Generation Control Equipment (atomic power, hydroelectric power, thermal power plant control system, etc.) 5 Medical Equipment (life-support equipment, pacemakers, dialysis controllers, etc.) 6 Information Processing Equipment (large scale computer systems, etc.) 7 Electric Heating Appliances, Combustion devices (gas fan heaters, oil fan heaters, etc.) 8 Rotary Motion Equipment 9 Security Systems J And any similar types of equipment 1. Circuit Design 1.1 Operating Temperature and Storage Temperature When operating a components-mounted circuit, please be sure to observe the “Operating Temperature Range”, written in delivery specifications. Please remember not to use the product under the condition that exceeds the specified maximum temperature. Storage temperature of PCB after mounting Thermistors, which is not operated, should be within the specified “Storage Temperature Range” in the delivery specifications. 1.2 Operating Power The electricity applied to between terminals of Thermistors should be under the specified maximum power dissipation. There are possibilities of breakage and burn-out due to excessive self-heating of Thermistors, if the power exceeds maximum power dissipation when operating. Please consider installing protection circuit for your circuit to improve the safety, in case of abnormal voltage application and so on. Thermistors’ performance of temperature detection would be deteriorated if self-heating occurs, even when you use it under the maximum power dissipation. Please consider the maximum power dissipation and dissipation factor. [Maximum power dissipation] · The Maximum power that can be continuously applied under static air at a certain ambient temperature. The Maximum power dissipation under an ambient temperature of 25 °C or less is the same with the rated maximum power dissipation, and Maximum power dissipation beyond 25 °C depends on the Decreased power dissipation curve below. Decreased power dissipation curve Maximum power dissipation/ Rated maximum power dissipation (%) Operating Conditions and Circuit Design 120 100 80 60 40 20 0 −25 0 25 50 75 100 125 150 175 Ambient temperature (°C) [Dissipation factor] · The constant amount power required to raise the temperature of the Thermistor 1 °C through self heat generation under stable temperatures. Dissipation factor (mW/°C) = Power consumption of Thermistor / Temperature rise of element Design and specifications are each subject to change without notice. Ask factory for the current technical specifications before purchase and/or use. Should a safety concern arise regarding this product, please be sure to contact us immediately. 00 Jun. 2015 NTC Thermistors for automotive devices (chip type) 1.3 Environmental Restrictions The Thermistors shall not be operated and/or stored under the following conditions. (1) Environmental conditions (a) Under direct exposure to water or salt water (b) Under conditions where water can condense and/or dew can form (c) Under conditions containing corrosive gases such as hydrogen sulfide, sulfurous acid, chlorine and ammonia (2) Mechanical conditions The place where vibration or impact that exceeds specified conditions written in delivery specification is loaded. 1.4 Measurement of Resistance The resistance of the Thermistors varies depending on ambient temperatures and self-heating. To measure the resistance value when examining circuit configuration and conducting receiving inspection and so on, the following points should be taken into consideration: 1 Measurement temp : 25±0.1 °C Measurement in liquid (silicon oil, etc.) is recommended for a stable measurement temperature. 2 Power : 0.10 mW max. 4 terminal measurement with a constant-current power supply is recommended. (2) The land size shall be designed to have equal space, on both right and left sides. If the amount of solder on both sides is not equal, the component may be cracked by stress, since the side with a larger amount of solder solidifies later during cooling. Recommended Amount of Solder (a) Excessive amount There is a possibility of performance deterioration by heat shock (temperature cycles), which causes cracks, from alumina substrate. Please confirm that the substrate you use does not deteriorate the Thermistors’ quality. (1) Solder resist shall be utilized to equalize the amounts of solder on both sides. (2) Solder resist shall be used to divide the pattern for the following cases; · Components are arranged closely. · The Thermistor is mounted near a component with lead wires. · The Thermistor is placed near a chassis. Refer to the table below. Prohibited Applications and Recommended Applications Item Mixed mounting with a component with lead wires Arrangement near chassis 2.2 Design of Land Pattern (1) Recommended land dimensions are shown below. Use the proper amount of solder in order to prevent cracking. Using too much solder places excessive stress on the Thermistors. Retro-fitting of component with lead wires Lateral arrangement Solder resist c Land b Unit (mm) Size Code (EIA) The lead wire of a component with lead wires Chassis Solder (Ground solder) Improved applications by pattern division Solder resist Solder resist A lead wire of Soldering Retro-fitted component iron Portion to be excessively soldered Land Solder resist Solder resist 2.4 Component Layout a Component dimensions L W T Prohibited applications Electrode pattern Recommended Land Dimensions SMD (c) Insufficient amount 2.3 Utilization of Solder Resist 2. Design of Printed Circuit Board 2.1 Selection of Printed Circuit Boards (b) Proper amount a b c 0(0402) 1.0 0.5 0.5 0.4 to 0.5 0.4 to 0.5 0.4 to 0.5 1(0603) 1.6 0.8 0.8 0.8 to 1.0 0.6 to 0.8 0.6 to 0.8 To prevent the crack of Thermistors, try to place it on the position that could not easily be affected by the bending stress of substrate while mounting procedures or procedures afterwards. Placement of the Thermistors near heating elements also requires the great care to be taken in order to avoid stresses from rapid heating and cooling. Design and specifications are each subject to change without notice. Ask factory for the current technical specifications before purchase and/or use. Should a safety concern arise regarding this product, please be sure to contact us immediately. 00 Jun. 2015 NTC Thermistors for automotive devices (chip type) (1) To minimize mechanical stress caused by the warp or bending of a PC board, please follow the recommended Thermistors’ layout below. Prohibited layout Recommended layout Layout the Thermistors sideways against the stressing direction (2) The following layout is for your reference since mechanical stress near the dividing/breaking position of a PC board varies depending on the mounting position of the Thermistors. E D Perforation C A B Slit Magnitude of stress A>B=C>D>E (3) The magnitude of mechanical stress applied to the Thermistors when dividing the circuit board in descending order is as follows: push back < slit < V-groove < perforation. Also take into account the layout of the Thermistors and the dividing/breaking method. (4) When the Thermistors are placed near heating elements such as heater, etc., cracks from thermal stresses may occur under following situation: · Soldering the Thermistors directly to heating elements. · Sharing the land with heating elements. If planning to conduct above-mentioned mounting and/or placement, please contact us in advance. 2.5 Mounting Density and Spaces Intervals between components should not be too narrow to prevent the influence from solder bridges and solder balls. The space between components should be carefully determined. Precautions for Assembly 1. Storage (1) The Thermistors shall be stored between 5 to 40 °C and 20 to 70 % RH, not under severe conditions of high temperature and humidity. (2) If stored in a place where humidity, dust, or corrosive gasses (hydrogen sulfide, sulfurous acid, hydrogen chloride and ammonia, etc.) are contained, the solderability of terminal electrodes will be deteriorated. In addition, storage in a places where the heat or direct sunlight exposure occur will cause mounting problems due to deformation of tapes and reels and components and taping/reels sticking together. (3) Do not store components longer than 6 months. Check the solderability of products that have been stored for more than 6 months before use 2. Chip Mounting Consideration (1) When mounting the Thermistors/components on a PC board, the Thermistor bodies shall be free from excessive impact loads such as mechanical impact or stress due to the positioning, pushing force and displacement of vacuum nozzles during mounting. (2) Maintenance and inspection of the Chip Mounter must be performed regularly. (3) If the bottom dead center of the vacuum nozzle is too low, the Thermistor will crack from excessive force during mounting. The following precautions and recommendations are for your reference in use. (a) Set and adjust the bottom dead center of the vacuum nozzles to the upper surface of the PC board after correcting the warp of the PC board. (b) Set the pushing force of the vacuum nozzle during mounting to 1 to 3 N in static load. (c) For double surface mounting, apply a supporting pin on the rear surface of the PC board to suppress the bending of the PC board in order to minimize the impact of the vacuum nozzles. Typical examples are shown in the table below. Item Single surface mouting Prohibited mounting Crack Recommended mounting The supporting pin does not necessarily have to be positioned beneath the Thermistor. Supporting pin Double surface mounting Separation of Solder Crack Supporting pin (d) Adjust the vacuum nozzles so that their bottom dead center during mounting is not too low. (4) The closing dimensions of the positioning chucks shall be controlled. Maintenance and replacement of positioning chucks shall be performed regularly to prevent chipping or cracking of the Thermistors caused by mechanical impact during positioning due to worn positioning chucks. (5) Maximum stroke of the nozzle shall be adjusted so that the maximum bending of PC board does not exceed 0.5 mm at 90 mm span. The PC board shall be supported by an adequate number of supporting pins. 3. Selection of Soldering Flux Soldering flux may seriously affect the performance of the Thermistors. The following shall be confirmed before use. (1) The soldering flux should have a halogen based content of 0.1 wt% (converted to chlorine) or below. Do not use soldering flux with strong acid. (2) When applying water-soluble soldering flux, wash the Thermistors sufficiently because the soldering flux residue on the surface of PC boards may deteriorate the insulation resistance on the Thermistors’ surface. Design and specifications are each subject to change without notice. Ask factory for the current technical specifications before purchase and/or use. Should a safety concern arise regarding this product, please be sure to contact us immediately. 00 Jun. 2015 NTC Thermistors for automotive devices (chip type) 4. Soldering 4.1 Reflow Soldering The reflow soldering temperature conditions are composed of temperature curves of Preheating, Temp. rise, Heating, Peak and Gradual cooling. Large temperature difference inside the Thermistors caused by rapid heat application to the Thermistors may lead to excessive thermal stresses, contributing to the thermal cracks. The Preheating temperature requires controlling with great care so that tombstone phenomenon may be prevented. Temperature 140 to 180 °C Preheating temp 2Temp. rise to Peak temp. 220 °C min. 3Heating 260 °C max. 4Peak Peak temp. 5Gradual cooling to 140 °C Period or Speed 60 to 120 sec Item 1Preheating 1 to 4 °C /sec △T Temperature (°C) △T 3 sec max. △T : Allowable temperature difference △T < 150 °C 2 Temp. rise 5 Gradual cooling 180 Preheating 60 to 120 sec 4 Peak 140 3 Heating Time 60 to 120 sec Gradual cooling 60 sec max. 10 sec max. 260 1 Preheating Recommended profile of Hand soldering (EX) 2 to 5 °C /sec Recommended profile of Reflow soldering (EX) 220 (b) Preheating: Conduct sufficient pre-heating, and make sure that the temperature difference between solder and Thermistors’ surface is 150 °C or less. (c) Temperature of Iron tip: 300 °C max. (The required amount of solder shall be melted in advance on the soldering tip.) (d) Gradual cooling: After soldering, the Thermistors shall be cooled gradually at room temperature. 60 sec max. △T : Allowable temperature difference △T < 150 °C The rapid cooling (forced cooling) during Gradual cooling part should be avoided, because this may cause defects such as the thermal cracks, etc. When the Thermistors are immersed into a cleaning solvent, make sure that the surface temperatures of the devices do not exceed 100 °C. Per for ming reflow soldering twice under the conditions shown in the figure above [Recommended profile of Reflow soldering (EX)] will not cause any problems. However, pay attention to the possible warp and bending of the PC board. 4.2 Hand Soldering Hand soldering typically causes significant temperature change, which may induce excessive thermal stresses inside the Thermitors, resulting in the thermal cracks, etc. In order to prevent any defects, the following should be observed. · The temperature of the soldering tips should be controlled with special care. · The direct contact of soldering tips with the Thermistors and/or terminal electrodes should be avoided. · Dismounted Thermistors shall not be reused. (1) Condition 1 (with preheating) (a) Soldering: Use thread solder (f1 mm or below) which contains flux with low chlorine, developed for precision electronic equipment. (2) Condition 2 (without preheating) Hand soldering can be performed without preheating, by following the conditions below: (a) Soldering iron tip shall never directly touch the ceramic and terminal electrodes of the Thermistors. (b) The lands are sufficiently preheated with a soldering iron tip before sliding the soldering iron tip to the terminal electrodes of the Thermistors for soldering. Conditions of Hand soldering without preheating Item Temperature of Iron tip Wattage Shape of Iron tip Soldering time with a soldering iron Condition 270 °C max. 20 W max. f3 mm max. 3 sec max. 5. Post Soldering Cleaning 5.1 Cleaning solvent Soldering flux residue may remain on the PC board if cleaned with an inappropriate solvent. This may deteriorate the electrical characteristics and reliability of the Thermistors. 5.2 Cleaning conditions Inappropriate cleaning conditions such as insufficient cleaning or excessive cleaning may impair the electrical characteristics and reliability of the Thermistors. (1) Insufficient cleaning can lead to: (a) The halogen substance found in the residue of the soldering flux may cause the metal of terminal electrodes to corrode. (b) The halogen substance found in the residue of the soldering flux on the surface of the Thermistors may change resistance values. (c) Water-soluble soldering flux may have more remarkable tendencies of (a) and (b) above compared to those of rosin soldering flux. Design and specifications are each subject to change without notice. Ask factory for the current technical specifications before purchase and/or use. Should a safety concern arise regarding this product, please be sure to contact us immediately. 00 Jun. 2015 NTC Thermistors for automotive devices (chip type) (2) Excessive cleaning can lead to: (a) When using ultrasonic cleaner, make sure that the output is not too large, so that the substrate will not resonate. The resonation causes the cracks in Varistors and/or solders, and deteriorates the strength of the terminal electrodes. Please follow these conditions for Ultrasonic cleaning: Ultrasonic wave output : 20 W/L max. Ultrasonic wave frequency : 40 kHz max. Ultrasonic wave cleaning time : 5 min. max. 5.3 Contamination of Cleaning solvent Cleaning with contaminated cleaning solvent may cause the same results as insufficient cleaning due to the high density of liberated halogen. (2) Dividing/Breaking of the PC boards shall be done carefully at moderate speed by using a jig or apparatus to protect the Thermistors on the boards from mechanical damage. (3) Examples of PCB dividing/breaking jigs: The outline of PC board breaking jig is shown below. When PC boards are broken or divided, loading points should be close to the jig to minimize the extent of the bending Also, planes with no parts mounted on should be used as plane of loading, in order to prevent tensile stress induced by the bending, which may cause cracks of the Thermistors or other parts mounted on the PC boards. Outline of Jig 6. Inspection Process The pressure from measuring terminal pins might bend the PCB when implementing circuit inspection after mounting Thermistors on PCB, and as a result, cracking may occur. (1) Mounted PC boards shall be supported by an adequate number of supporting pins on the back with bend settings of 90 mm span 0.5 mm max. (2) Confirm that the measuring pins have the right tip shape, are equal in height, have the right pressure, and are set in the correct positions. The following figures are for your reference to avoid bending the PC board. Item Prohibited setting Recommended setting V-groove PC board splitting jig Prohibited dividing Recommended dividing Loading direction Loading point PC board PC board Chip component Loading direction V-groove Chip component Loading point V-groove Check pin Check pin 9. Mechanical Impact Bending of PC board Separated, Crack PC board Supporting pin 7. Protective Coating When the surface of a PC board on which the Thermistors have been mounted is coated with resin to protect against moisture and dust, it shall be confirmed that the protective coating does not affect the performance of Varistors. (1) Choose the material that does not emit the decomposition and/or reaction gas. The Gas may affect the composing members of the Varistors. (2) Shrinkage and expansion of resin coating when curing may apply stress to the Varistors and may lead to occurrence of cracks. (1) The Thermistors shall be free from any excessive mechanical impact. The Thermistor body is made of ceramics and may be damaged or cracked if dropped. N eve r use a T h ermisto r w hich has be en dropped; their quality may be impaired and failure rate increased. (2) When handling PC boards with Thermistors mounted on them, do not allow the Thermistors to collide with another PC board. When mounted PC boards are handled or stored in a stacked state, the corner of a PC board might strike Thermistors, and the impact of the strike may cause damage or cracking and can deteriorate the withstand voltage and insulation resistance of the Thermistor. 8. Dividing/Breaking of PC Boards Mounted PCB (1) Please be careful not to stress the substrate with bending/twisting when dividing, after mounting components including Varistors. Abnormal and excessive mechanical stress such as bending or torsion shown below can cause cracking in the Thermistors. Bending Torsion Crack Crack Floor Other The various precautions described above are typical. For special mounting conditions, please contact us. Design and specifications are each subject to change without notice. Ask factory for the current technical specifications before purchase and/or use. Should a safety concern arise regarding this product, please be sure to contact us immediately. 00 Jun. 2015