PCBA加工(gong)是(shi)經過(guo)SMT和DIP等工(gong)藝將所需電(dian)子(zi)元器(qi)(qi)件焊接安(an)裝到(dao)PCB板上的整個過(guo)程。其中所用到(dao)的電(dian)子(zi)元器(qi)(qi)件通常有下面一些主要類型：電(dian)阻器(qi)(qi)、電(dian)容器(qi)(qi)、電(dian)感線圈、變壓器(qi)(qi)、二極(ji)管(guan)、三極(ji)管(guan)、場效應管(guan)。

電阻器

電阻器是(shi)具有(you)一(yi)定電阻值的電子(zi)元(yuan)器件，簡稱(cheng)電阻，是(shi)組成電子(zi)電路不(bu)可缺少的元(yuan)件。電阻基本單位是(shi)歐姆（Ω），電阻常(chang)用(yong)下面兩種符號(hao)表示。

電容器

電容是(shi)一(yi)種儲能(neng)元件，儲存電荷的能(neng)力用(yong)電容量(liang)來標注(zhu)，基本(ben)單位(wei)是(shi)法(fa)拉（F），常用(yong)單位(wei)是(shi)微法(fa)（μF）和(he)皮法(fa)（pF）。電容器多用(yong)于電路的濾波、耦合、調諧、隔直(zhi)、延時(shi)、交(jiao)流旁路和(he)能(neng)量(liang)轉(zhuan)換(huan)。電容常用(yong)下面的符號表示(shi)。

電感線圈

電(dian)(dian)(dian)(dian)感器(qi)(qi)(qi)是(shi)能夠把電(dian)(dian)(dian)(dian)能轉化為(wei)磁能而存儲(chu)起來的元(yuan)件。電(dian)(dian)(dian)(dian)感器(qi)(qi)(qi)的結構類似于變(bian)壓器(qi)(qi)(qi)，但只有一個繞組。電(dian)(dian)(dian)(dian)感器(qi)(qi)(qi)具有一定的電(dian)(dian)(dian)(dian)感，它只阻(zu)礙(ai)電(dian)(dian)(dian)(dian)流(liu)的變(bian)化。如(ru)果(guo)電(dian)(dian)(dian)(dian)感器(qi)(qi)(qi)在(zai)沒有電(dian)(dian)(dian)(dian)流(liu)通過(guo)的狀態下，電(dian)(dian)(dian)(dian)路(lu)接通時(shi)它將試圖阻(zu)礙(ai)電(dian)(dian)(dian)(dian)流(liu)流(liu)過(guo)它;如(ru)果(guo)電(dian)(dian)(dian)(dian)感器(qi)(qi)(qi)在(zai)有電(dian)(dian)(dian)(dian)流(liu)通過(guo)的狀態下，電(dian)(dian)(dian)(dian)路(lu)斷開時(shi)它將試圖維持電(dian)(dian)(dian)(dian)流(liu)不變(bian)。電(dian)(dian)(dian)(dian)感器(qi)(qi)(qi)又稱扼流(liu)器(qi)(qi)(qi)、電(dian)(dian)(dian)(dian)抗(kang)器(qi)(qi)(qi)、動態電(dian)(dian)(dian)(dian)抗(kang)器(qi)(qi)(qi)。電(dian)(dian)(dian)(dian)感線圈與電(dian)(dian)(dian)(dian)阻(zu)、電(dian)(dian)(dian)(dian)容(rong)一樣(yang)，是(shi)電(dian)(dian)(dian)(dian)子電(dian)(dian)(dian)(dian)路(lu)中最常(chang)用的元(yuan)器(qi)(qi)(qi)件之一。基本(ben)單位是(shi)亨利（H）。電(dian)(dian)(dian)(dian)感常(chang)用下面的符號表示(shi)。

變壓器

在一個鐵芯(xin)上繞(rao)兩組線圈就構成了變(bian)壓(ya)器，接在交流電源的線圈（L1）習慣(guan)上稱(cheng)(cheng)之為初級線圈，與負(fu)載相連的線圈（L2）稱(cheng)(cheng)次(ci)級線圈。變(bian)壓(ya)器在電路(lu)中主要(yao)是用(yong)(yong)來提升(sheng)或降低交流電壓(ya)，或者是進行阻抗變(bian)換以滿足不同電路(lu)的阻抗匹配。變(bian)壓(ya)器常用(yong)(yong)下面符號表示。

二極管

二極管(guan)，是一個(ge)由(you)p型(xing)半導體和(he)(he)n型(xing)半導體形成(cheng)(cheng)(cheng)的(de)(de)(de)(de)(de)p-n結(jie)(jie)，在(zai)其界(jie)面(mian)處兩側形成(cheng)(cheng)(cheng)空(kong)間電(dian)(dian)(dian)(dian)(dian)荷層，并(bing)建(jian)有(you)自(zi)(zi)建(jian)電(dian)(dian)(dian)(dian)(dian)場(chang)(chang)。當不存在(zai)外(wai)(wai)加(jia)電(dian)(dian)(dian)(dian)(dian)壓(ya)時(shi)，由(you)于(yu)p-n結(jie)(jie)兩邊載流(liu)(liu)(liu)(liu)子濃度差引(yin)(yin)起(qi)(qi)的(de)(de)(de)(de)(de)擴散電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)和(he)(he)自(zi)(zi)建(jian)電(dian)(dian)(dian)(dian)(dian)場(chang)(chang)引(yin)(yin)起(qi)(qi)的(de)(de)(de)(de)(de)漂移電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)相等而處于(yu)電(dian)(dian)(dian)(dian)(dian)平衡狀態。當外(wai)(wai)界(jie)有(you)正向(xiang)電(dian)(dian)(dian)(dian)(dian)壓(ya)偏置時(shi)，外(wai)(wai)界(jie)電(dian)(dian)(dian)(dian)(dian)場(chang)(chang)和(he)(he)自(zi)(zi)建(jian)電(dian)(dian)(dian)(dian)(dian)場(chang)(chang)的(de)(de)(de)(de)(de)互相抑消作用使載流(liu)(liu)(liu)(liu)子的(de)(de)(de)(de)(de)擴散電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)增加(jia)引(yin)(yin)起(qi)(qi)了正向(xiang)電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)。當外(wai)(wai)界(jie)有(you)反(fan)向(xiang)電(dian)(dian)(dian)(dian)(dian)壓(ya)偏置時(shi)，外(wai)(wai)界(jie)電(dian)(dian)(dian)(dian)(dian)場(chang)(chang)和(he)(he)自(zi)(zi)建(jian)電(dian)(dian)(dian)(dian)(dian)場(chang)(chang)進(jin)一步加(jia)強，形成(cheng)(cheng)(cheng)在(zai)一定反(fan)向(xiang)電(dian)(dian)(dian)(dian)(dian)壓(ya)范圍內與反(fan)向(xiang)偏置電(dian)(dian)(dian)(dian)(dian)壓(ya)值無關的(de)(de)(de)(de)(de)反(fan)向(xiang)飽(bao)和(he)(he)電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)。當外(wai)(wai)加(jia)的(de)(de)(de)(de)(de)反(fan)向(xiang)電(dian)(dian)(dian)(dian)(dian)壓(ya)高到一定程度時(shi)，p-n結(jie)(jie)空(kong)間電(dian)(dian)(dian)(dian)(dian)荷層中的(de)(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)場(chang)(chang)強度達到臨界(jie)值，產(chan)生大(da)量電(dian)(dian)(dian)(dian)(dian)子空(kong)穴對，形成(cheng)(cheng)(cheng)了數值很大(da)的(de)(de)(de)(de)(de)反(fan)向(xiang)擊(ji)穿(chuan)電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)，稱為二極管(guan)的(de)(de)(de)(de)(de)擊(ji)穿(chuan)現象。二極管(guan)常用下(xia)面(mian)符號表示。

三極管

三極(ji)(ji)管(guan)的全(quan)稱應(ying)為(wei)半導(dao)體(ti)三極(ji)(ji)管(guan)，也(ye)稱為(wei)雙極(ji)(ji)型(xing)晶(jing)體(ti)管(guan)或晶(jing)體(ti)三極(ji)(ji)管(guan)，是(shi)一種電(dian)流控(kong)制電(dian)流的半導(dao)體(ti)器件。其作用(yong)(yong)是(shi)把微弱信號(hao)放大成輻值較大的電(dian)信號(hao)，也(ye)用(yong)(yong)作無觸點開關。三極(ji)(ji)管(guan)常(chang)用(yong)(yong)下面符(fu)號(hao)表示。

場效應管

場效應(ying)晶體管(guan)(guan)屬(shu)于電(dian)(dian)壓控制型半(ban)導體器件(jian)。與三極管(guan)(guan)相比，場效應(ying)管(guan)(guan)具有輸入電(dian)(dian)阻高、噪聲小、功(gong)耗低(di)、熱穩(wen)定(ding)性好、動(dong)態范圍大、易于集(ji)成(cheng)、沒有二次擊穿現象、安全工作區(qu)域寬等優點，易于做成(cheng)大規模集(ji)成(cheng)電(dian)(dian)路(lu)，在(zai)高頻、中(zhong)頻、低(di)頻、直流(liu)、開關及(ji)阻抗變換電(dian)(dian)路(lu)中(zhong)有廣(guang)泛(fan)應(ying)用(yong)。場效應(ying)管(guan)(guan)常用(yong)下面(mian)符號表示。

以上是PCBA加工中常用到(dao)的一些電(dian)子元器(qi)件，也是最基礎的一些電(dian)子元器(qi)件，在幾乎所有不(bu)同的PCBA加工中均會涉及到(dao)上述(shu)器(qi)件的使(shi)用