常用原理图元件符号、PCB封装及所在库序号元件名称封装名称原理图符号及库PCB封装形式及库1Battery直流电源BAT-2 BatteryBT?MiscellaneousDevices.IntLibMiscellaneous Devices PCB.PcbLib2 Bell铃PIN2BellLS?MiscellaneousDevices.IntLibMiscellaneous Connector PCB.PcbLib3Bridge1二极管整流桥E-BIP-P4/D Bridge1D?MiscellaneousDevices.IntLibBridge Rectifier.PcbLib4Bridge2集成块整流桥E-BIP-P4/xAC2V+1AC4V-3Bridge2D?MiscellaneousDevices.IntLibBridge Rectifier.PcbLib5 Buzzer蜂鸣器PIN2BuzzerLS?MiscellaneousDevices.IntLibMiscellaneous Connector PCB.PcbLib6Cap无极性电容RAD-0.3CapC?MiscellaneousDevices.IntLibMiscellaneous Devices PCB.PcbLib7Cap极性电容100pFCap Pol1C?号8 Electro 1电解电容RB-.2/.4(99) MiscellaneousDevices.Lib(99)Miscellaneous.ddb9 Cap Semi贴片电容C3216-1206CapC?MiscellaneousDevices.IntLibMiscellaneous Devices PCB.PcbLib10D Zener稳压二极管DIODE-0.7D ZenerD?Miscellaneous Devices PCB.PcbLib11Diode二极管DSO0C2/X DiodeD?MiscellaneousDevices.IntLibSmall Outline Diode - 2 C-BendLeads.PcbLib12DpyRED-CA数码管DIP10abfcgdeVCC1234567abcdefg8dpdp910NCDpy Red-CADS?MiscellaneousDevices.IntLibMiscellaneous Devices PCB.PcbLib13 Fuse 2熔断器PIN-W2/E Fuse 2F?MiscellaneousDevices.IntLibMiscellaneous Devices PCB.PcbLib14 Inductor电感C1005-0402 10mHInductorL?MiscellaneousDevices.IntLibMiscellaneous Devices PCB.PcbLib15JFET-P场效应管CAN-3/D321JFET-PQ?号Miscellaneous Devices.IntLib Vertical, Single-Row, Flange Mountwith Tab.PcbLib16 Jumper跳线RAD-0.2 JumperW?MiscellaneousDevices.IntLibMiscellaneous Devices PCB.PcbLib17Header5单排插针HDR1X512345Header 5JP?MiscellaneousConnectors.IntLibMiscellaneous Connector PCB.PcbLib18 Lamp灯PIN2 LampDS?MiscellaneousDevices.IntLibMiscellaneous Connector PCB.PcbLib19LED1发光二极管LED-112LED1DS?MiscellaneousDevices.IntLibMiscellaneous Devices PCB.PcbLib20 MHDR2×4双排插针MHDR2×412345678MHDR2X4JP?MiscellaneousConnectors.IntLibMiscellaneous Connector PCB.PcbLib21Mic2麦克风DIP2 Mic2MK?MiscellaneousDevices.IntLibMiscellaneous Connector PCB.PcbLib22 Motor Serxo伺服电机RAD-0.4Motor ServoB?MiscellaneousMiscellaneous Devices PCB.PcbLib号Devices.IntLib23NPN三极管BCY-W3NPNQ?MiscellaneousDevices.IntLibCylinder with Flat Index.PcbLib24 Op Amp运放CAN-8/D23647185Op AmpAR?MiscellaneousDevices.IntLib CAN - Circle pin arrangement.PcbLib25 Phonejack2插孔PIN2 Phonejack2J?MiscellaneousConnectors.IntLibMiscellaneous Connector PCB.PcbLib26 Phone PNP感光三极管SFM-T2/XPhoto PNPQ?MiscellaneousDevices.IntLibVertical, Single-Row, Flange Mountwith Tab.PcbLib27Phone Sen感光二极管PIN2 Photo SenD?MiscellaneousDevices.IntLibMiscellaneous Connector PCB.PcbLib28PNP三极管SO-G3/CPNPQ?MiscellaneousDevices.IntLibSOT 23.PcbLib号29 Relay SPST继电器DIP-P4Relay-SPSTK?MiscellaneousDevices.IntLibDIP - Peg Leads.PcbLib30 Res2电阻AXIAL-0.4 1KRes2R?MiscellaneousDevices.IntLibMiscellaneous Devices PCB.PcbLib31Rpot2电位器VR2 1KRPot2R?MiscellaneousDevices.IntLibMiscellaneous Devices PCB.PcbLib32SCR晶闸管SFM-T3SCRQ?MiscellaneousDevices.IntLibVertical, Single-Row, Flange Mountwith Tab.PcbLib33 Speaker喇叭PIN2 Speak erLS?MiscellaneousDevices.IntLibMiscellaneous Connector PCB.PcbLib34 SW-DIP4 DIP-16 12345678161514131211109SW-DIP8S?MiscellaneousDevices.IntLibDual-In-Line Package.PcbLib35 SW-PB按钮SPST-2 SW-PBS?MiscellaneousDevices.IntLibMiscellaneous Devices PCB.PcbLib号36 SW-SPDT单刀双掷SPDT-3 SW-SPDTS?MiscellaneousDevices.IntLibMiscellaneous Devices PCB.PcbLib37 SW-SPST开关SPST-2 SW-SPSTS?MiscellaneousDevices.IntLibMiscellaneous Devices PCB.PcbLib38 Trans Ideal变压器TRF-4Trans IdealT?MiscellaneousDevices.IntLibMiscellaneous Devices PCB.PcbLib39Triac双向可控硅SFM-TTriacQ?MiscellaneousDevices.IntLibVertical, Single-Row, Flange Mountwith Tab.PcbLib40 XTAL晶振BCY-W2/D3.112XTALY?MiscellaneousDevices.IntLib Crystal Oscillator.PcbLib41 L7805AC-V三端稳压SFM-T3/E10.4vIN13OUT2GNDL7805AC-VU?ST Power MgtVoltageRegulator.IntLibVertical, Single-Row, Flange Mountwith Tab.PcbLib42 LM741CN集成运放DIP-885326741LM741CNU?NSC OperationalAmplifier.IntLibDual-In-Line Package.PcbLib聚乙烯（PE）简介1.1聚乙烯化学名称：聚乙烯英文名称：polyethylene，简称PE结构式：聚乙烯是乙烯经聚合制得的一种热塑性树脂，也包括乙烯与少量α-烯烃的共聚物。
聚乙烯是五大合成树脂之一，是我国合成树脂中产能最大、进口量最多的品种。
1.1.1聚乙烯的性能1.一般性能聚乙烯为白色蜡状半透明材料，柔而韧，比水轻，无嗅、无味、无毒，常温下不溶于一般溶剂，吸水性小，但由于其为线性分子可缓慢溶于某些有机溶剂，且不发生溶胀。
工业上为使用和贮存的方便通常在聚合后加入适量的塑料助剂进行造粒，制成半透明的颗粒状物料。
PE易燃，燃烧时有蜡味，并伴有熔融滴落现象。
聚乙烯的性质因品种而异，主要取决于分子结构和密度，也与聚合工艺及后期造粒过程中加入的塑料助剂有关。
2.力学性能PE是典型的软而韧的聚合物。
除冲击强度较高外，其他力学性能绝对值在塑料材料中都是较低的。
PE密度增大，除韧性以外的力学性能都有所提高。
LDPE 由于支化度大，结晶度低，密度小，各项力学性能较低，但韧性良好，耐冲击。
HDPE支化度小，结晶度高，密度大，拉伸强度、刚度和硬度较高，韧性较差些。
相对分子质量增大，分子链间作用力相应增大，所有力学性能，包括韧性也都提高。
几种PE的力学性能见表1-1。
表1-1 几种PE力学性能数据3.热性能PE受热后，随温度的升高，结晶部分逐渐熔化，无定形部分逐渐增多。
其熔点与结晶度和结晶形态有关。
HDPE的熔点约为125～137℃，MDPE的熔点约为126～134℃，LDPE的熔点约为105～115℃。