PCBA加(jia)工(gong)是經過SMT和DIP等工(gong)藝將所(suo)需電子(zi)元(yuan)器件(jian)焊接安裝(zhuang)到(dao)PCB板上的(de)整(zheng)個過程。其中所(suo)用到(dao)的(de)電子(zi)元(yuan)器件(jian)通常有下(xia)面一些主要類型：電阻器、電容器、電感線圈(quan)、變壓器、二極管、三(san)極管、場效應管。

電阻器

電(dian)(dian)阻器(qi)是具(ju)有一定電(dian)(dian)阻值(zhi)的電(dian)(dian)子(zi)元器(qi)件，簡稱電(dian)(dian)阻，是組成電(dian)(dian)子(zi)電(dian)(dian)路不可缺少的元件。電(dian)(dian)阻基本單位是歐姆（Ω），電(dian)(dian)阻常(chang)用下面兩種(zhong)符號表示。

電容器

電(dian)(dian)容(rong)是(shi)一種儲(chu)能元件(jian)，儲(chu)存電(dian)(dian)荷的(de)能力用電(dian)(dian)容(rong)量(liang)來標注(zhu)，基本單位(wei)是(shi)法拉（F），常用單位(wei)是(shi)微法（μF）和(he)皮法（pF）。電(dian)(dian)容(rong)器多用于(yu)電(dian)(dian)路的(de)濾(lv)波、耦合、調諧、隔(ge)直、延時、交(jiao)流旁(pang)路和(he)能量(liang)轉換。電(dian)(dian)容(rong)常用下面的(de)符號(hao)表示。

電感線圈

電(dian)(dian)(dian)感(gan)(gan)(gan)器(qi)是能(neng)夠把電(dian)(dian)(dian)能(neng)轉化為磁(ci)能(neng)而存(cun)儲起來(lai)的(de)元件。電(dian)(dian)(dian)感(gan)(gan)(gan)器(qi)的(de)結構類似于變(bian)壓器(qi)，但只(zhi)有(you)一個繞組。電(dian)(dian)(dian)感(gan)(gan)(gan)器(qi)具有(you)一定的(de)電(dian)(dian)(dian)感(gan)(gan)(gan)，它只(zhi)阻(zu)礙電(dian)(dian)(dian)流(liu)的(de)變(bian)化。如果電(dian)(dian)(dian)感(gan)(gan)(gan)器(qi)在(zai)沒有(you)電(dian)(dian)(dian)流(liu)通過(guo)的(de)狀(zhuang)態(tai)下(xia)，電(dian)(dian)(dian)路(lu)(lu)接通時(shi)它將試(shi)圖阻(zu)礙電(dian)(dian)(dian)流(liu)流(liu)過(guo)它;如果電(dian)(dian)(dian)感(gan)(gan)(gan)器(qi)在(zai)有(you)電(dian)(dian)(dian)流(liu)通過(guo)的(de)狀(zhuang)態(tai)下(xia)，電(dian)(dian)(dian)路(lu)(lu)斷開時(shi)它將試(shi)圖維(wei)持電(dian)(dian)(dian)流(liu)不變(bian)。電(dian)(dian)(dian)感(gan)(gan)(gan)器(qi)又稱扼(e)流(liu)器(qi)、電(dian)(dian)(dian)抗器(qi)、動(dong)態(tai)電(dian)(dian)(dian)抗器(qi)。電(dian)(dian)(dian)感(gan)(gan)(gan)線圈與(yu)電(dian)(dian)(dian)阻(zu)、電(dian)(dian)(dian)容一樣，是電(dian)(dian)(dian)子(zi)電(dian)(dian)(dian)路(lu)(lu)中最(zui)常用(yong)的(de)元器(qi)件之一。基本單位是亨利（H）。電(dian)(dian)(dian)感(gan)(gan)(gan)常用(yong)下(xia)面的(de)符號(hao)表示(shi)。

變壓器

在(zai)一(yi)個鐵芯上繞(rao)兩組線(xian)(xian)圈(quan)就構成了變(bian)壓器，接在(zai)交流電(dian)源的(de)線(xian)(xian)圈(quan)（L1）習慣上稱之為初級線(xian)(xian)圈(quan)，與負(fu)載相連的(de)線(xian)(xian)圈(quan)（L2）稱次級線(xian)(xian)圈(quan)。變(bian)壓器在(zai)電(dian)路中主(zhu)要是(shi)用(yong)來提升或(huo)降低交流電(dian)壓，或(huo)者是(shi)進行(xing)阻(zu)抗變(bian)換以滿(man)足不同電(dian)路的(de)阻(zu)抗匹配。變(bian)壓器常(chang)用(yong)下面(mian)符號表示。

二極管

二(er)(er)極管，是一(yi)個由(you)p型半導(dao)體(ti)(ti)和(he)n型半導(dao)體(ti)(ti)形(xing)成的(de)(de)(de)(de)(de)p-n結(jie)，在其界面處(chu)兩(liang)側形(xing)成空間(jian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)荷層，并建(jian)(jian)有自(zi)建(jian)(jian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)場(chang)(chang)。當(dang)不存在外加(jia)(jia)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)時(shi)(shi)，由(you)于p-n結(jie)兩(liang)邊載流子(zi)(zi)濃度(du)差引起的(de)(de)(de)(de)(de)擴散(san)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流和(he)自(zi)建(jian)(jian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)場(chang)(chang)引起的(de)(de)(de)(de)(de)漂(piao)移(yi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流相(xiang)等而處(chu)于電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)平衡(heng)狀態。當(dang)外界有正(zheng)向(xiang)(xiang)(xiang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)偏置時(shi)(shi)，外界電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)場(chang)(chang)和(he)自(zi)建(jian)(jian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)場(chang)(chang)的(de)(de)(de)(de)(de)互相(xiang)抑消作用(yong)使載流子(zi)(zi)的(de)(de)(de)(de)(de)擴散(san)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流增加(jia)(jia)引起了正(zheng)向(xiang)(xiang)(xiang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流。當(dang)外界有反(fan)(fan)向(xiang)(xiang)(xiang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)偏置時(shi)(shi)，外界電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)場(chang)(chang)和(he)自(zi)建(jian)(jian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)場(chang)(chang)進(jin)一(yi)步加(jia)(jia)強，形(xing)成在一(yi)定反(fan)(fan)向(xiang)(xiang)(xiang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)范圍內與反(fan)(fan)向(xiang)(xiang)(xiang)偏置電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)值無關的(de)(de)(de)(de)(de)反(fan)(fan)向(xiang)(xiang)(xiang)飽和(he)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流。當(dang)外加(jia)(jia)的(de)(de)(de)(de)(de)反(fan)(fan)向(xiang)(xiang)(xiang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)高到(dao)一(yi)定程度(du)時(shi)(shi)，p-n結(jie)空間(jian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)荷層中的(de)(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)場(chang)(chang)強度(du)達到(dao)臨界值，產生大量(liang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)子(zi)(zi)空穴(xue)對，形(xing)成了數值很大的(de)(de)(de)(de)(de)反(fan)(fan)向(xiang)(xiang)(xiang)擊(ji)(ji)穿電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流，稱(cheng)為二(er)(er)極管的(de)(de)(de)(de)(de)擊(ji)(ji)穿現象。二(er)(er)極管常用(yong)下面符號(hao)表(biao)示(shi)。

三極管

三(san)極(ji)(ji)(ji)管(guan)的全(quan)稱應為半(ban)導體(ti)三(san)極(ji)(ji)(ji)管(guan)，也(ye)稱為雙極(ji)(ji)(ji)型晶體(ti)管(guan)或晶體(ti)三(san)極(ji)(ji)(ji)管(guan)，是(shi)一種電流(liu)控制電流(liu)的半(ban)導體(ti)器件。其(qi)作用(yong)是(shi)把微弱(ruo)信號放大(da)成輻值較(jiao)大(da)的電信號，也(ye)用(yong)作無觸點開(kai)關。三(san)極(ji)(ji)(ji)管(guan)常用(yong)下面符(fu)號表示(shi)。

場效應管

場(chang)效(xiao)應晶(jing)體(ti)管(guan)屬于(yu)電(dian)壓控制型半導體(ti)器(qi)件。與(yu)三極管(guan)相比，場(chang)效(xiao)應管(guan)具有(you)輸入電(dian)阻高、噪聲小(xiao)、功耗低、熱穩(wen)定性好、動態范圍大、易(yi)于(yu)集成(cheng)、沒有(you)二次擊穿現象、安全工作區域寬等優(you)點，易(yi)于(yu)做成(cheng)大規模集成(cheng)電(dian)路(lu)，在高頻、中(zhong)頻、低頻、直流(liu)、開關及阻抗變換電(dian)路(lu)中(zhong)有(you)廣泛應用(yong)。場(chang)效(xiao)應管(guan)常用(yong)下面符號表(biao)示(shi)。

以上(shang)是(shi)PCBA加工(gong)中常用(yong)到的(de)一些電(dian)子(zi)元器件，也是(shi)最(zui)基(ji)礎的(de)一些電(dian)子(zi)元器件，在幾(ji)乎所有不同的(de)PCBA加工(gong)中均會涉及到上(shang)述器件的(de)使(shi)用(yong)