Leadless Chip Thermometrics NTC Thermistor , SMD / Surface Mount Thermistor
SMD / Surface Mount Thermistor, NTC Leadless Chip Thermometrics Thermistors Feature
Ultra small size2012
Lead(pb)freeproduct.Wide operating temperature:﹣40℃ to﹢125℃.
Lowresistance and high B-value available.
Superiorheatresistance to soldering and excellent solderability.
Productconforming to ROHS directive.
SMD / Surface Mount Thermistor, NTC Leadless Chip Thermometrics Thermistors Applications
SMD / Surface Mount Thermistor, NTC Leadless Chip Thermometrics Thermistors Filed
Equipment to mobile communication TCXOs(temperature compensated type quartz oscillator),RF circuits (power amp circuits, temperature monitoring circuits) LCD panel temperature compensated crystal oscillator, witch is the key device for mobile phones.□ Temperature compensating circuit of LCD□ Computer relate equipment
CPU periphery temperature monitoring circuits, temperature compensation circuit of optical pickup for DVD writing, temperature compensated in HDD.
Auto-focus circuits , plunger peripheral circuits, battery circuits ,battery pack temperature control circuits.□ Equipment relate to car audio
Varistor types of pickup temperature compensation circuits, temperature compensation for various types of circuits
Optical communication related equipment
Laser transmission circuit temperature compensation
SMD / Surface Mount Thermistor, NTC Leadless Chip Thermometrics Thermistors Electrical Characteristics
|Part Number||R25( kΩ)||B value|
SMD / Surface Mount Thermistor, NTC Leadless Chip Thermometrics Thermistors Production Dimension
|Type||L (mm)||W (mm)||H(mm)||L1 (mm)|
SMD / Surface Mount Thermistor, NTC Leadless Chip Thermometrics Thermistors Soldering Recommendation
The principal techniques used for the soldering of components in surface mount technology are infrared reflow and wave soldering.
When wave soldering. The SMD is attach to the circuit board by means of an adhesive. The assembly is then place on a conveyor and run though the soldering process to contact the wave. Wave soldering is the most strenuous of the processes. To avoid the possibility of generating stresses due to thermal shock., a preheat stage in the soldering process is recommended, and the peak temperature of the solder process should be rigidly controlled. The following is the typical profiles.
WAVE SOLDER PROFILE
When reflow soldering, the device is placed a solder paste on the substrate ,as the solder paste is heated, it re-flows and solders the unite to board. When using a reflow process ,care should be taken to ensure that the SMD is not subjected to an thermal gradient steeper than 4 degrees per second; the ideal gradient being 2degrees per second. During the soldering process, preheating to within 100 degrees of the soldier’s peak temperature is essential to minimize thermal shock. The following is typical profile.
REFLOW SOLDER PROFILE
Carrier tape transparent cover tape should be heat-sealed to carry the products, and the reel should be used to reel the carrier tape.
The adhesion of the heat-sealed cover tape shall be 40﹢20/﹣15 grams.
Both the head and the end portion of taping shall be empty for reel package and SMT auto-pickup machine. And a normal paper tape shall be connected in the head of taping for the operator handle.
Taping Dimensions Unit:mm
Packaging Quantity Unit:pcs
Enviromental Reliability Test
|Characteristic||Test method and description|
|High Temperature Storage||The specimen shall be subjected to 125℃ for 1000 hours in a thermostatic bath without load and then stored at room temperature and humidity for 1 to 2 hours. The change of varistor voltage shall be within 10%.|
|Temperature Cycle||The temperature cycle of specified temperature shall be repeated five times and then stored at room temperature and humidity for one two hours. The change of varistor voltage shall be within 10%and mechanical damage shall be examined.||Step||Temperature||Period|
|High Temperature Load||After being continuously applied the maximum allowable voltage at 85℃ for 1000hours, the specimen shall be stored at room temperature and humidity for one or hours, the change of varistor voltage shall be within 10%.|
Damp Heat Load/
|The specimen should be subjected to 40℃,90 to 95%RH environment, and the maximum allowable voltage applied for 1000 hours, then stored at room temperature and humidity for one or two hours. The change of varistor voltage shall be within 10%.|
|Low Temperature Storage||The specimen should be subjected to -40℃, without load for 1000 hours and then stored at room temperature for one two hours. The change of varistor voltage shall be within 10%.|