High Pressure Over-current Protection With Ptcr Thermistor Research

The PTCR thermistor is a ferroelectric semiconductor ceramics with positivetemperature characteristic, so it is widely used in household appliances, marine aviation,auto industry, electronic communication and so on.With the ever-changing science and technology and the rapid development ofelectronic communication, the security of a variety of high-precision instrumentation,program-controlled switches and main distributing frame(MDF) are particularlyimportant, In these instruments, large integrated circuit with low rating voltage, weakover-current protection and low resistor is widely used,so the power of lightningprotection and high voltage ability is relatively require.And for such equipment thePTCR protection element is not only meeting the need of low electric resistance, highfrequency current impact ability, high voltage-withstand ability and short action timecharacteristics, but also meeting the need of good reliability and good failure mode (nofire, no burst).So the several reliability quality of the high voltage impact ability,temperature cycling, the current impact and lighting resistance ability to the classover-current protection with PTCR thermistor is put forward higher requirements. Thethesis is based on the purpose of the research topic. In this paper, high voltage impact,high reliability, over-current protection MZ23-2-50RM-08P9PTCR thermistor isdesigned and developed as the goal.1.The preparation process of the PTC powder materials and PTCR thermistor isdetailed description and characterization, According to analysing and derived: theselection and prescription and mixing of the PTC raw materials, pre-firing, sintering ofthe PTC chip and the electrode preparation of PTCR components is the key processeswhich affect the PTCR thermistor characteristics.2.According to discoursing the full designing and developing of theMZ23-2-50RM-08P9PTCR thermistor for over-current protection of communicationMDF, the production process parameters of this product are determined.3.According to discoursing the variously common failure modes of PTCRthermistors, the mechanism of PTCR failure modes are got, and the corresponding improvements and process solutions are descriptived. There are many effectivelymethod in order to improve the performance and reliability of the MZ23-2-50RM-08P9PTCR thermistor and supplied production and technical support.According to studying of this paper, researching Y2O3and Mn common mingled,and innovational introducting heat treatment process, and successfully developed theMZ23-2-50RM-08P9PTCR thermistor for the over-current protection ofcommunication MDF, its voltage impact value is greater than700v, the performancetarget are fully met the YD/T741-2002requirements, In this paper, The studying plays acertain theoretical researching and production guiding role of the high voltage impactand high reliability of over-current protection PTCR thermistor.