常见的被动元器件有哪些？

被动元件的例子有很多如电阻、电容、电感等元件的资料。简单地讲就是需能（电）源的器件叫有源器件，无需能（电）源的器件就是无源器件。有源器件一般用来信号放大、变换等，无源器件用来进行信号传输，或者通过方向性进行“信号放大”。

被动元件是台湾电子行业对某些电子元器件的叫法，区别于主动元件。在中国大陆则称为无源器件和有源器件。从工作特点来看，被动元件具备自身不消耗电能，或把电能转变为不同形式的其他能量；同时只需输入信号，不需要外加电源就能正常工作等特性。

主动元件：电路元件中能够执行资料运算、处理的元件。包括各式各样的晶片，例如半导体元件中的电晶体、积体电路、影像管和显示器等都属于主动元件。被动元件：不影响信号基本特徵，而仅令讯号通过而未加以更动的电路元件。

自然界的物质按导电能力可分为导体、绝缘体和半导体三类。半导体材料是指室温下导电性介于导电材料和绝缘材料之间的一类功能材料。靠电子和空穴两种载流子实现导电，室温时电阻率一般在10-5～107欧·米之间。通常电阻率随温度升高而增大；若掺入活性杂质或用光、射线辐照，可使其电阻率有几个数量级的变化。1906年制成了碳化硅检波器。

1947年发明晶体管以后，半导体材料作为一个独立的材料领域得到了很大的发展，并成为电子工业和高技术领域中不可缺少的材料。特性和参数半导体材料的导电性对某些微量杂质极敏感。纯度很高的半导体材料称为本征半导体，常温下其电阻率很高，是电的不良导体。在高纯半导体材料中掺入适当杂质后，由于杂质原子提供导电载流子，使材料的电阻率大为降低。这种掺杂半导体常称为杂质半导体。杂质半导体靠导带电子导电的称N型半导体，靠价带空穴导电的称P型半导体。

不同类型半导体间接触（构成PN结）或半导体与金属接触时，因电子（或空穴）浓度差而产生扩散，在接触处形成位垒，因而这类接触具有单向导电性。利用PN结的单向导电性，可以制成具有不同功能的半导体器件，如二极管、三极管、晶闸管等。

此外，半导体材料的导电性对外界条件（如热、光、电、磁等因素）的变化非常敏感，据此可以制造各种敏感元件，用于信息转换。半导体材料的特性参数有禁带宽度、电阻率、载流子迁移率、非平衡载流子寿命和位错密度。禁带宽度由半导体的电子态、原子组态决定，反映组成这种材料的原子中价电子从束缚状态激发到自由状态所需的能量。电阻率、载流子迁移率反映材料的导电能力。非平衡载流子寿命反映半导体材料在外界作用（如光或电场）下内部载流子由非平衡状态向平衡状态过渡的弛豫特性。位错是晶体中最常见的一类缺陷。位错密度用来衡量半导体单晶材料晶格完整性的程度，对于非晶态半导体材料，则没有这一参数。半导体材料的特性参数不仅能反映半导体材料与其他非半导体材料之间的差别，更重要的是能反映各种半导体材料之间甚至同一种材料在不同情况下，其特性的量值差别。

半导体材料的种类

常用的半导体材料分为元素半导体和化合物半导体。元素半导体是由单一元素制成的半导体材料。主要有硅、锗、硒等，以硅、锗应用最广。化合物半导体分为二元系、三元系、多元系和有机化合物半导体。二元系化合物半导体有Ⅲ-Ⅴ族（如砷化镓、磷化镓、磷化铟等）、Ⅱ-Ⅵ族（如硫化镉、硒化镉、碲化锌、硫化锌等）、Ⅳ-Ⅵ族（如硫化铅、硒化铅等）、Ⅳ-Ⅳ族（如碳化硅）化合物。三元系和多元系化合物半导体主要为三元和多元固溶体，如镓铝砷固溶体、镓锗砷磷固溶体等。有机化合物半导体有萘、蒽、聚丙烯腈等，还处于研究阶段。

此外，还有非晶态和液态半导体材料，这类半导体与晶态半导体的最大区别是不具有严格周期性排列的晶体结构。制备不同的半导体器件对半导体材料有不同的形态要求，包括单晶的切片、磨片、抛光片、薄膜等。半导体材料的不同形态要求对应不同的加工工艺。常用的半导体材料制备工艺有提纯、单晶的制备和薄膜外延生长。

所有的半导体材料都需要对原料进行提纯，要求的纯度在6个“9”以上，最高达11个“9”以上。提纯的方法分两大类，一类是不改变材料的化学组成进行提纯，称为物理提纯；另一类是把元素先变成化合物进行提纯，再将提纯后的化合物还原成元素，称为化学提纯。物理提纯的方法有真空蒸发、区域精制、拉晶提纯等，使用最多的是区域精制。化学提纯的主要方法有电解、络合、萃娶精馏等，使用最多的是精馏。

由于每一种方法都有一定的局限性，因此常使用几种提纯方法相结合的工艺流程以获得合格的材料。绝大多数半导体器件是在单晶片或以单晶片为衬底的外延片上作出的。成批量的半导体单晶都是用熔体生长法制成的。直拉法应用最广，80％的硅单晶、大部分锗单晶和锑化铟单晶是用此法生产的，其中硅单晶的最大直径已达300毫米。在熔体中通入磁场的直拉法称为磁控拉晶法，用此法已生产出高均匀性硅单晶。在坩埚熔体表面加入液体覆盖剂称液封直拉法，用此法拉制砷化镓、磷化镓、磷化铟等分解压较大的单晶。悬浮区熔法的熔体不与容器接触，用此法生长高纯硅单晶。

水平区熔法用以生产锗单晶。水平定向结晶法主要用于制备砷化镓单晶，而垂直定向结晶法用于制备碲化镉、砷化镓。用各种方法生产的体单晶再经过晶体定向、滚磨、作参考面、切片、磨片、倒角、抛光、腐蚀、清洗、检测、封装等全部或部分工序以提供相应的晶片。在单晶衬底上生长单晶薄膜称为外延。外延的方法有气相、液相、固相、分子束外延等。

工业生产使用的主要是化学气相外延，其次是液相外延。金属有机化合物气相外延和分子束外延则用于制备量子阱及超晶格等微结构。非晶、微晶、多晶薄膜多在玻璃、陶瓷、金属等衬底上用不同类型的化学气相沉积、磁控溅射等方法制成。

半导体和绝缘体之间的差异主要来自两者的能带（band）宽度不同。绝缘体的能带比半导体宽，意即绝缘体价带中的载子必须获得比在半导体中更高的能量才能跳过能带，进入传导带中。室温下的半导体导电性有如绝缘体，只有极少数的载子具有足够的能量进入传导带。因此，对于一个在相同电场下的纯质半导体（intrinsicsemiconductor）和绝缘体会有类似的电特性，不过半导体的能带宽度小于绝缘体也意味著半导体的导电性更容易受到控制而改变。

纯质半导体的电气特性可以藉由植入杂质的过程而永久改变，这个过程通常称为“掺杂”（doping）。依照掺杂所使用的杂质不同，掺杂后的半导体原子周围可能会多出一个电子或一个电洞，而让半导体材料的导电特性变得与原本不同。如果掺杂进入半导体的杂质浓度够高，半导体也可能会表现出如同金属导体般的电性。在掺杂了不同极性杂质的半导体接面处会有一个内建电场（built-inelectricfield），内建电场和许多半导体元件的 *** 作原理息息相关。

除了藉由掺杂的过程永久改变电性外，半导体亦可因为施加于其上的电场改变而动态地变化。半导体材料也因为这样的特性，很适合用来作为电路元件，例如晶体管。晶体管属于主动式的（有源）半导体元件（activesemiconductordevices），当主动元件和被动式的（无源）半导体元件（passivesemiconductordevices）如电阻器（resistor）或是电容器（capacitor）组合起来时，可以用来设计各式各样的集成电路产品，例如微处理器。

当电子从传导带掉回价带时，减少的能量可能会以光的形式释放出来。这种过程是制造发光二极管（light-emittingdiode,LED）以及半导体激光（semiconductorlaser）的基础，在商业应用上都有举足轻重的地位。而相反地，半导体也可以吸收光子，透过光电效应而激发出在价带的电子，产生电讯号。这即是光探测器（photodetector）的来源，在光纤通讯（fiber-opticcommunications）或是太阳能电池（solarcell）的领域是最重要的元件。

半导体有可能是单一元素组成，例如硅。也可以是两种或是多种元素的化合物（compound），常见的化合物半导体有砷化镓（galliumarsenide,GaAs）或是磷化铝铟镓（aluminiumgalliumindiumphosphide,AlGaInP）等。合金（alloy）也是半导体材料的来源之一，如锗硅（silicongermanium,SiGe）或是砷化镓铝（aluminiumgalliumarsenide,AlGaAs）等。

In addition to improvements in chip performance, the shell packaging technology is also a great breakthrough, IR inversion in the development of field-effect transistor, also known as "FlipFET" on the basis of this year introduced the DirectFET, as shown in Figure 6. Its source and gate inversion result can be directly welded in the printed circuit board, the drain at the top of the weld metal in its shell, if necessary, by the radiator or direct contact with the equipment enclosure. DirectFET size equivalent to the traditional SO-8 plastic (plastic with an area of about 4x5 mm2) shell. In such a small device, the first structure of a double-sided cooling. It is a lead frame, no-lead solder joints of the device, it brought about a series of advantages: it's non-resistor chip package (DFPR) is only 0. 1mW, device thickness of only 0. 7mm, resistance and parasitic inductance have dropped significantly. Such characteristics make it especially suitable for the above-mentioned computer of the latest generation of CPU. In the multi-phase circuits, each with only two of 30 security DirectFET can transfer current. Increase its current rate of 400 per delicate security, the working frequency of 1-2 MHz.

Secondly, you must be focused on power semiconductor devices in the IC direction: as a result of the development of MOSFET and IGBT, and their matching to provide a trigger signal power integrated circuit PIC (Power IC) have also developed rapidly. At that time, also known as MOS gate drive MGD (MOS Gate Driver) or control integrated circuit CIC (Control IC). With the expansion of the scope of application: such as motor drives, lighting, various power supply and so on, CIC of the cultivars have been rapidly increasing. These CIC in the development process

And gradually from a simple function to trigger the special needs of a wide range of applications development. PIC is the earliest that can be used in high voltage IC, therefore, also known as high-voltage IC (HVIC). However, many applications such as communications, computers, portable power supply and so on, they do not require high voltage, but demand for the special needs of the development of application specific integrated circuit. Because of their combination and application of power semiconductor devices, we have the power to include them in a class of semiconductor devices. So now the power semiconductor devices in the family, there are many integrated circuits. Many of these power devices with integrated circuits inside, some outside while the separation of power devices. Judging from this point, the limits of power and microelectronics has become increasingly blurred. If a large number of computer applications in power modulation device voltage LDO (Low Drop Out) is one example. It does not belong to switch applications.

As a result of a large number of integrated circuits into the power semiconductor devices, which consider the power semiconductor integrated circuits and devices to do the same in the chip or device on the development of the natural line of thought. Done in the same chip, the original is the concept of power integrated circuits, but their power often relatively small. Done in the same package, easy to increase power capacity, a number of passive components is also possible to join, here often called multi-chip module (MCM).

IR last year iPOWIR developed is a typical multi-chip module. It will power devices to control the use of integrated circuits, or in combination with pulse-width modulation (PWM) integrated circuit, according to the needs of power supply design, using BGA packaging technology portfolio in the same device (as shown in Figure 7) . Multi-chip device that greatly simplifies the power supply design staff. Components reduces the number and percentage of the area, there has been a lot of performance improvement. iPOWIR development is considered DC-DC conversion of the future. But, in fact, a wide range of applications in other fields, as long as the requirements of further integration, MCM structure and will there will be more and more. Therefore, it is the power semiconductor devices important direction of development.

In the above presentation, the development of MOSFET has been referred to as 4C industry provides an important foundation. 4C industries which, at present it is the most active direction of the product. We can understand: in the communications, computer, consumer electronics and automotive development, will require many, many close contacts and IC of all types of power semiconductor devices. Each of these aspects can be used to introduce a lot of space. Not detailed here.

Add: Conclusion

To sum up, the power semiconductor devices the past few years, constantly changed a lot. So can no longer look at a fixed vision of the development of power semiconductor devices. For example, not simply thyristor power semiconductor devices and an equal sign painting, or drawing an equal sign and discrete devices. Must not power semiconductor devices and microelectronics artificially separated, it seems only semiconductor microelectronics. These will impede the development of power semiconductor devices, in the long run will hinder the development of microelectronic devices. Development strategy in order to avoid the power semiconductor devices as a simple process only to be completed on the low-tech products. And the preferential policies available only to integrated circuit industry. China has not been very good to the development of modern power semiconductor devices, the lack of modern power semiconductor devices is a comprehensive understanding of the factors I am afraid. Information technology to stimulate industrialization in the wave, it is imperative that different semiconductor devices have a balanced development.

Conclusion

To sum up, the power semiconductor devices the past few years, constantly changed a lot. So can no longer look at a fixed vision of the development of power semiconductor devices. For example, not simply thyristor power semiconductor devices and an equal sign painting, or drawing an equal sign and discrete devices. Must not power semiconductor devices and microelectronics artificially separated, it seems only semiconductor microelectronics. These will impede the development of power semiconductor devices, in the long run will hinder the development of microelectronic devices. Development strategy in order to avoid the power semiconductor devices as a simple process only to be completed on the low-tech products. And the preferential policies available only to integrated circuit industry. China has not been very good to the development of modern power semiconductor devices, the lack of modern power semiconductor devices is a comprehensive understanding of the factors I am afraid. Information technology to stimulate industrialization in the wave, it is imperative that different semiconductor devices have a balanced development.

---