PCBA加工是(shi)經過SMT和DIP等(deng)工藝將所(suo)需電(dian)(dian)子元器(qi)(qi)件焊接安裝到(dao)PCB板上的整個過程(cheng)。其中所(suo)用到(dao)的電(dian)(dian)子元器(qi)(qi)件通(tong)常(chang)有下面(mian)一些主要類型：電(dian)(dian)阻器(qi)(qi)、電(dian)(dian)容(rong)器(qi)(qi)、電(dian)(dian)感線圈、變壓器(qi)(qi)、二極(ji)管、三(san)極(ji)管、場效應(ying)管。

電阻器

電(dian)阻(zu)器是(shi)具有一定電(dian)阻(zu)值的電(dian)子元器件，簡稱電(dian)阻(zu)，是(shi)組成電(dian)子電(dian)路(lu)不(bu)可缺少的元件。電(dian)阻(zu)基(ji)本單位是(shi)歐姆(mu)（Ω），電(dian)阻(zu)常用下面兩種符號表示。

電容器

電(dian)(dian)(dian)容是一(yi)種儲能元件，儲存(cun)電(dian)(dian)(dian)荷的(de)能力用電(dian)(dian)(dian)容量來標(biao)注(zhu)，基(ji)本單位是法拉(la)（F），常(chang)(chang)用單位是微(wei)法（μF）和(he)皮法（pF）。電(dian)(dian)(dian)容器多(duo)用于電(dian)(dian)(dian)路(lu)的(de)濾波、耦合、調(diao)諧、隔(ge)直(zhi)、延時、交(jiao)流旁路(lu)和(he)能量轉(zhuan)換。電(dian)(dian)(dian)容常(chang)(chang)用下面的(de)符號表(biao)示。

電感線圈

電(dian)(dian)(dian)(dian)(dian)(dian)感(gan)器是能夠(gou)把電(dian)(dian)(dian)(dian)(dian)(dian)能轉化(hua)為磁能而存(cun)儲起來的(de)元(yuan)件。電(dian)(dian)(dian)(dian)(dian)(dian)感(gan)器的(de)結構(gou)類似于變壓(ya)器，但只(zhi)有一(yi)個繞組。電(dian)(dian)(dian)(dian)(dian)(dian)感(gan)器具有一(yi)定(ding)的(de)電(dian)(dian)(dian)(dian)(dian)(dian)感(gan)，它(ta)(ta)只(zhi)阻礙電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)的(de)變化(hua)。如果(guo)電(dian)(dian)(dian)(dian)(dian)(dian)感(gan)器在(zai)沒有電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)通過的(de)狀態(tai)(tai)下，電(dian)(dian)(dian)(dian)(dian)(dian)路(lu)接通時(shi)它(ta)(ta)將試圖(tu)阻礙電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)流(liu)(liu)過它(ta)(ta);如果(guo)電(dian)(dian)(dian)(dian)(dian)(dian)感(gan)器在(zai)有電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)通過的(de)狀態(tai)(tai)下，電(dian)(dian)(dian)(dian)(dian)(dian)路(lu)斷開時(shi)它(ta)(ta)將試圖(tu)維(wei)持電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)不變。電(dian)(dian)(dian)(dian)(dian)(dian)感(gan)器又稱扼(e)流(liu)(liu)器、電(dian)(dian)(dian)(dian)(dian)(dian)抗器、動態(tai)(tai)電(dian)(dian)(dian)(dian)(dian)(dian)抗器。電(dian)(dian)(dian)(dian)(dian)(dian)感(gan)線(xian)圈與電(dian)(dian)(dian)(dian)(dian)(dian)阻、電(dian)(dian)(dian)(dian)(dian)(dian)容一(yi)樣，是電(dian)(dian)(dian)(dian)(dian)(dian)子電(dian)(dian)(dian)(dian)(dian)(dian)路(lu)中(zhong)最常(chang)用(yong)的(de)元(yuan)器件之(zhi)一(yi)。基本單(dan)位是亨利(li)（H）。電(dian)(dian)(dian)(dian)(dian)(dian)感(gan)常(chang)用(yong)下面的(de)符(fu)號表示。

變壓器

在一個鐵芯上繞兩組線圈(quan)就構成了變(bian)(bian)(bian)壓器，接在交流電(dian)源的(de)線圈(quan)（L1）習(xi)慣上稱(cheng)之為初(chu)級(ji)線圈(quan)，與(yu)負(fu)載相連的(de)線圈(quan)（L2）稱(cheng)次級(ji)線圈(quan)。變(bian)(bian)(bian)壓器在電(dian)路(lu)中主要(yao)是用來(lai)提升或降(jiang)低(di)交流電(dian)壓，或者是進行(xing)阻抗變(bian)(bian)(bian)換(huan)以滿(man)足不(bu)同電(dian)路(lu)的(de)阻抗匹配。變(bian)(bian)(bian)壓器常用下面符號表(biao)示。

二極管

二(er)極管(guan)，是(shi)一個由p型半導體(ti)和n型半導體(ti)形成(cheng)的(de)(de)(de)(de)p-n結(jie)，在(zai)其界(jie)(jie)(jie)(jie)面(mian)處(chu)兩側形成(cheng)空間(jian)電(dian)(dian)荷(he)層，并(bing)建(jian)有(you)自(zi)建(jian)電(dian)(dian)場(chang)(chang)。當不存在(zai)外加(jia)電(dian)(dian)壓(ya)(ya)(ya)時(shi)，由于p-n結(jie)兩邊載(zai)流(liu)(liu)(liu)子(zi)(zi)濃度(du)差引起(qi)的(de)(de)(de)(de)擴散電(dian)(dian)流(liu)(liu)(liu)和自(zi)建(jian)電(dian)(dian)場(chang)(chang)引起(qi)的(de)(de)(de)(de)漂移電(dian)(dian)流(liu)(liu)(liu)相等而處(chu)于電(dian)(dian)平衡狀態(tai)。當外界(jie)(jie)(jie)(jie)有(you)正向(xiang)電(dian)(dian)壓(ya)(ya)(ya)偏置時(shi)，外界(jie)(jie)(jie)(jie)電(dian)(dian)場(chang)(chang)和自(zi)建(jian)電(dian)(dian)場(chang)(chang)的(de)(de)(de)(de)互相抑消作用使載(zai)流(liu)(liu)(liu)子(zi)(zi)的(de)(de)(de)(de)擴散電(dian)(dian)流(liu)(liu)(liu)增加(jia)引起(qi)了正向(xiang)電(dian)(dian)流(liu)(liu)(liu)。當外界(jie)(jie)(jie)(jie)有(you)反(fan)(fan)向(xiang)電(dian)(dian)壓(ya)(ya)(ya)偏置時(shi)，外界(jie)(jie)(jie)(jie)電(dian)(dian)場(chang)(chang)和自(zi)建(jian)電(dian)(dian)場(chang)(chang)進一步加(jia)強，形成(cheng)在(zai)一定反(fan)(fan)向(xiang)電(dian)(dian)壓(ya)(ya)(ya)范圍內與反(fan)(fan)向(xiang)偏置電(dian)(dian)壓(ya)(ya)(ya)值(zhi)無(wu)關的(de)(de)(de)(de)反(fan)(fan)向(xiang)飽和電(dian)(dian)流(liu)(liu)(liu)。當外加(jia)的(de)(de)(de)(de)反(fan)(fan)向(xiang)電(dian)(dian)壓(ya)(ya)(ya)高到(dao)一定程度(du)時(shi)，p-n結(jie)空間(jian)電(dian)(dian)荷(he)層中的(de)(de)(de)(de)電(dian)(dian)場(chang)(chang)強度(du)達到(dao)臨界(jie)(jie)(jie)(jie)值(zhi)，產生大(da)量(liang)電(dian)(dian)子(zi)(zi)空穴(xue)對，形成(cheng)了數值(zhi)很大(da)的(de)(de)(de)(de)反(fan)(fan)向(xiang)擊穿電(dian)(dian)流(liu)(liu)(liu)，稱為二(er)極管(guan)的(de)(de)(de)(de)擊穿現(xian)象。二(er)極管(guan)常用下面(mian)符(fu)號表示。

三極管

三極管(guan)(guan)的(de)全稱(cheng)應為(wei)半導體(ti)(ti)三極管(guan)(guan)，也稱(cheng)為(wei)雙極型(xing)晶體(ti)(ti)管(guan)(guan)或晶體(ti)(ti)三極管(guan)(guan)，是一種電流控制(zhi)電流的(de)半導體(ti)(ti)器件(jian)。其作(zuo)用是把微弱信號(hao)(hao)放大成輻(fu)值較大的(de)電信號(hao)(hao)，也用作(zuo)無觸點開關(guan)。三極管(guan)(guan)常(chang)用下面符號(hao)(hao)表示(shi)。

場效應管

場效應(ying)(ying)晶體管(guan)屬于(yu)(yu)電壓(ya)控制型半導體器件。與三極(ji)管(guan)相比，場效應(ying)(ying)管(guan)具(ju)有(you)輸入電阻高、噪(zao)聲小、功耗(hao)低、熱穩(wen)定性(xing)好、動態范(fan)圍大、易于(yu)(yu)集成(cheng)(cheng)(cheng)、沒有(you)二次擊穿現象、安全工作區域(yu)寬等優(you)點，易于(yu)(yu)做成(cheng)(cheng)(cheng)大規模集成(cheng)(cheng)(cheng)電路，在高頻(pin)、中(zhong)頻(pin)、低頻(pin)、直流、開(kai)關及阻抗變換電路中(zhong)有(you)廣泛(fan)應(ying)(ying)用。場效應(ying)(ying)管(guan)常(chang)用下面(mian)符(fu)號表示。

以上(shang)是(shi)PCBA加工(gong)中常用到的一些(xie)電子(zi)元器件，也是(shi)最基礎的一些(xie)電子(zi)元器件，在幾乎所有不(bu)同(tong)的PCBA加工(gong)中均會涉(she)及到上(shang)述(shu)器件的使用