PCBA加工是經過(guo)SMT和(he)DIP等工藝(yi)將所需(xu)電(dian)子元(yuan)器(qi)件(jian)焊(han)接安裝到PCB板上的整個(ge)過(guo)程。其(qi)中所用到的電(dian)子元(yuan)器(qi)件(jian)通常(chang)有下(xia)面(mian)一些主要類型：電(dian)阻(zu)器(qi)、電(dian)容器(qi)、電(dian)感線圈(quan)、變壓(ya)器(qi)、二極管(guan)、三極管(guan)、場效應管(guan)。

電阻器

電(dian)(dian)(dian)阻(zu)器是具有一(yi)定電(dian)(dian)(dian)阻(zu)值的(de)(de)電(dian)(dian)(dian)子元器件(jian)，簡稱電(dian)(dian)(dian)阻(zu)，是組成電(dian)(dian)(dian)子電(dian)(dian)(dian)路不可缺(que)少的(de)(de)元件(jian)。電(dian)(dian)(dian)阻(zu)基本單位是歐姆（Ω），電(dian)(dian)(dian)阻(zu)常用下(xia)面兩種符號(hao)表示(shi)。

電容器

電容(rong)(rong)(rong)是(shi)一種儲能元件(jian)，儲存(cun)電荷的(de)能力用(yong)電容(rong)(rong)(rong)量(liang)來標(biao)注，基本(ben)單(dan)位(wei)是(shi)法拉（F），常用(yong)單(dan)位(wei)是(shi)微法（μF）和皮法（pF）。電容(rong)(rong)(rong)器多(duo)用(yong)于電路的(de)濾波、耦合、調(diao)諧、隔(ge)直、延時(shi)、交流旁(pang)路和能量(liang)轉換。電容(rong)(rong)(rong)常用(yong)下面的(de)符號表示。

電感線圈

電(dian)(dian)感器(qi)(qi)(qi)是(shi)能夠把電(dian)(dian)能轉化為磁(ci)能而存儲起來的(de)(de)元件(jian)(jian)。電(dian)(dian)感器(qi)(qi)(qi)的(de)(de)結構類(lei)似于變壓器(qi)(qi)(qi)，但只(zhi)有(you)(you)一(yi)個繞組。電(dian)(dian)感器(qi)(qi)(qi)具有(you)(you)一(yi)定(ding)的(de)(de)電(dian)(dian)感，它(ta)只(zhi)阻礙電(dian)(dian)流(liu)(liu)(liu)的(de)(de)變化。如(ru)果電(dian)(dian)感器(qi)(qi)(qi)在沒有(you)(you)電(dian)(dian)流(liu)(liu)(liu)通過的(de)(de)狀態(tai)下，電(dian)(dian)路接通時它(ta)將試(shi)圖(tu)阻礙電(dian)(dian)流(liu)(liu)(liu)流(liu)(liu)(liu)過它(ta);如(ru)果電(dian)(dian)感器(qi)(qi)(qi)在有(you)(you)電(dian)(dian)流(liu)(liu)(liu)通過的(de)(de)狀態(tai)下，電(dian)(dian)路斷開時它(ta)將試(shi)圖(tu)維持電(dian)(dian)流(liu)(liu)(liu)不(bu)變。電(dian)(dian)感器(qi)(qi)(qi)又稱扼流(liu)(liu)(liu)器(qi)(qi)(qi)、電(dian)(dian)抗(kang)(kang)器(qi)(qi)(qi)、動態(tai)電(dian)(dian)抗(kang)(kang)器(qi)(qi)(qi)。電(dian)(dian)感線圈與電(dian)(dian)阻、電(dian)(dian)容一(yi)樣，是(shi)電(dian)(dian)子電(dian)(dian)路中最常用的(de)(de)元器(qi)(qi)(qi)件(jian)(jian)之一(yi)。基本單(dan)位是(shi)亨利(li)（H）。電(dian)(dian)感常用下面的(de)(de)符號表示。

變壓器

在(zai)一個鐵芯上(shang)(shang)繞兩組線圈(quan)就構成了變(bian)(bian)(bian)壓器，接在(zai)交(jiao)流(liu)電源的(de)(de)線圈(quan)（L1）習(xi)慣上(shang)(shang)稱(cheng)之為初級線圈(quan)，與負載(zai)相連的(de)(de)線圈(quan)（L2）稱(cheng)次級線圈(quan)。變(bian)(bian)(bian)壓器在(zai)電路中(zhong)主要是用來(lai)提升或降低交(jiao)流(liu)電壓，或者是進行阻抗變(bian)(bian)(bian)換以(yi)滿足不同電路的(de)(de)阻抗匹(pi)配。變(bian)(bian)(bian)壓器常用下面符號表示。

二極管

二極管，是(shi)一(yi)(yi)個由p型半導體和(he)n型半導體形(xing)(xing)成的(de)p-n結，在其(qi)界(jie)(jie)(jie)(jie)面處兩(liang)側形(xing)(xing)成空(kong)間電(dian)(dian)(dian)荷層，并(bing)建(jian)有(you)自(zi)建(jian)電(dian)(dian)(dian)場(chang)。當不(bu)存在外(wai)加(jia)(jia)(jia)電(dian)(dian)(dian)壓時，由于p-n結兩(liang)邊載流(liu)子濃度差引起(qi)(qi)的(de)擴散電(dian)(dian)(dian)流(liu)和(he)自(zi)建(jian)電(dian)(dian)(dian)場(chang)引起(qi)(qi)的(de)漂移(yi)電(dian)(dian)(dian)流(liu)相(xiang)等而處于電(dian)(dian)(dian)平衡狀態。當外(wai)界(jie)(jie)(jie)(jie)有(you)正向(xiang)(xiang)電(dian)(dian)(dian)壓偏(pian)置時，外(wai)界(jie)(jie)(jie)(jie)電(dian)(dian)(dian)場(chang)和(he)自(zi)建(jian)電(dian)(dian)(dian)場(chang)的(de)互相(xiang)抑(yi)消作(zuo)用使載流(liu)子的(de)擴散電(dian)(dian)(dian)流(liu)增加(jia)(jia)(jia)引起(qi)(qi)了(le)正向(xiang)(xiang)電(dian)(dian)(dian)流(liu)。當外(wai)界(jie)(jie)(jie)(jie)有(you)反(fan)向(xiang)(xiang)電(dian)(dian)(dian)壓偏(pian)置時，外(wai)界(jie)(jie)(jie)(jie)電(dian)(dian)(dian)場(chang)和(he)自(zi)建(jian)電(dian)(dian)(dian)場(chang)進一(yi)(yi)步加(jia)(jia)(jia)強(qiang)，形(xing)(xing)成在一(yi)(yi)定反(fan)向(xiang)(xiang)電(dian)(dian)(dian)壓范圍內與反(fan)向(xiang)(xiang)偏(pian)置電(dian)(dian)(dian)壓值(zhi)(zhi)無(wu)關的(de)反(fan)向(xiang)(xiang)飽和(he)電(dian)(dian)(dian)流(liu)。當外(wai)加(jia)(jia)(jia)的(de)反(fan)向(xiang)(xiang)電(dian)(dian)(dian)壓高到一(yi)(yi)定程度時，p-n結空(kong)間電(dian)(dian)(dian)荷層中的(de)電(dian)(dian)(dian)場(chang)強(qiang)度達到臨界(jie)(jie)(jie)(jie)值(zhi)(zhi)，產生(sheng)大量電(dian)(dian)(dian)子空(kong)穴對，形(xing)(xing)成了(le)數值(zhi)(zhi)很大的(de)反(fan)向(xiang)(xiang)擊穿(chuan)電(dian)(dian)(dian)流(liu)，稱(cheng)為二極管的(de)擊穿(chuan)現象。二極管常用下面符號(hao)表示。

三極管

三(san)(san)極管(guan)(guan)(guan)的(de)全稱(cheng)應為半導(dao)體三(san)(san)極管(guan)(guan)(guan)，也(ye)稱(cheng)為雙極型晶體管(guan)(guan)(guan)或(huo)晶體三(san)(san)極管(guan)(guan)(guan)，是(shi)一(yi)種電(dian)流控(kong)制電(dian)流的(de)半導(dao)體器件(jian)。其作用是(shi)把微弱信(xin)號(hao)放大成輻值(zhi)較(jiao)大的(de)電(dian)信(xin)號(hao)，也(ye)用作無觸點(dian)開關。三(san)(san)極管(guan)(guan)(guan)常用下面符號(hao)表示。

場效應管

場(chang)效(xiao)應(ying)(ying)晶體(ti)管(guan)屬于(yu)電(dian)壓控制型半導體(ti)器(qi)件。與三極管(guan)相(xiang)比，場(chang)效(xiao)應(ying)(ying)管(guan)具有(you)輸入電(dian)阻高(gao)、噪(zao)聲(sheng)小、功耗低、熱穩定性好、動(dong)態范(fan)圍大(da)、易于(yu)集成、沒有(you)二次擊穿現象(xiang)、安全工作(zuo)區域寬等優點，易于(yu)做(zuo)成大(da)規(gui)模集成電(dian)路，在高(gao)頻(pin)、中頻(pin)、低頻(pin)、直流、開關及阻抗變換(huan)電(dian)路中有(you)廣泛應(ying)(ying)用。場(chang)效(xiao)應(ying)(ying)管(guan)常用下面符(fu)號表示。

以上是PCBA加工中(zhong)(zhong)常用(yong)到(dao)的一些電(dian)子(zi)元器(qi)(qi)件(jian)，也是最基礎(chu)的一些電(dian)子(zi)元器(qi)(qi)件(jian)，在幾乎所有(you)不(bu)同的PCBA加工中(zhong)(zhong)均會涉及到(dao)上述器(qi)(qi)件(jian)的使用(yong)