對電(dian)路(lu)中電(dian)容(rong)元件(jian)的選用應該考慮(lv)以下幾個因素：

電子開發電容耐壓選擇

電(dian)子產(chan)品開發在選用(yong)電(dian)容(rong)時，元件的(de)耐壓一定要高(gao)于實(shi)際電(dian)路(lu)中的(de)工(gong)作(zuo)電(dian)壓，尤其值得注意(yi)的(de)是電(dian)子電(dian)路(lu)中要考慮到可能產(chan)生(sheng)的(de)高(gao)壓。

電子開發電容電容量選擇

在電(dian)(dian)子電(dian)(dian)路(lu)，電(dian)(dian)容(rong)量是(shi)根(gen)據某些性能指標(biao)確定的(de)，在確定容(rong)量時(shi)(shi)要根(gen)據標(biao)稱(cheng)系(xi)列選擇(ze)。如果通(tong)過標(biao)稱(cheng)系(xi)列找不到該電(dian)(dian)容(rong)的(de)容(rong)量數值(zhi)，可(ke)以通(tong)過串并(bing)聯的(de)方法解決(jue)(jue)或通(tong)過修改設計方案中(zhong)其(qi)他參數加以解決(jue)(jue)。在更換電(dian)(dian)路(lu)中(zhong)的(de)電(dian)(dian)容(rong)時(shi)(shi)最好選用原參數的(de)電(dian)(dian)容(rong)或性能指標(biao)優于原電(dian)(dian)路(lu)電(dian)(dian)容(rong)的(de)元件。

電子開發電容介質選擇

電(dian)(dian)容(rong)介(jie)(jie)(jie)質不同(tong)，其(qi)特性(xing)差(cha)異較大，用(yong)(yong)(yong)途也不完全相(xiang)同(tong)。在選(xuan)用(yong)(yong)(yong)電(dian)(dian)容(rong)的介(jie)(jie)(jie)質時，要首(shou)先(xian)了(le)解各介(jie)(jie)(jie)質的特性(xing)，然后確定適用(yong)(yong)(yong)何種場(chang)合。下面分別介(jie)(jie)(jie)紹幾(ji)種常用(yong)(yong)(yong)的固(gu)定電(dian)(dian)容(rong)的使用(yong)(yong)(yong)。

電(dian)(dian)(dian)(dian)(dian)(dian)(dian)解(jie)(jie)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)容(rong)是(shi)以(yi)鋁等金屬(shu)為(wei)正(zheng)極(ji)(ji)，在其表面(mian)形成(cheng)一層氧(yang)化(hua)膜(mo)為(wei)介質，介質與電(dian)(dian)(dian)(dian)(dian)(dian)(dian)極(ji)(ji)成(cheng)為(wei)不可分(fen)的(de)整體(ti)(ti)；負(fu)極(ji)(ji)是(shi)固(gu)體(ti)(ti)或非固(gu)體(ti)(ti)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)解(jie)(jie)質。由于構成(cheng)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)解(jie)(jie)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)容(rong)的(de)兩電(dian)(dian)(dian)(dian)(dian)(dian)(dian)極(ji)(ji)的(de)材(cai)料不同，因此它的(de)正(zheng)負(fu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)極(ji)(ji)分(fen)別標出，使用時一定(ding)要(yao)正(zheng)極(ji)(ji)端(duan)接(jie)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)路的(de)高電(dian)(dian)(dian)(dian)(dian)(dian)(dian)位(wei)(wei)，負(fu)極(ji)(ji)端(duan)接(jie)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)路的(de)低(di)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)位(wei)(wei)，否則會引起電(dian)(dian)(dian)(dian)(dian)(dian)(dian)容(rong)的(de)損壞。按照電(dian)(dian)(dian)(dian)(dian)(dian)(dian)極(ji)(ji)材(cai)料的(de)不同有鋁電(dian)(dian)(dian)(dian)(dian)(dian)(dian)解(jie)(jie)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)容(rong)、鉭電(dian)(dian)(dian)(dian)(dian)(dian)(dian)解(jie)(jie)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)容(rong)和鈮(ni)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)解(jie)(jie)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)容(rong)等幾種(zhong)。

云(yun)母(mu)(mu)電容(rong)是以云(yun)母(mu)(mu)片(pian)為介質的電容(rong)。它絕緣性能好、損耗小、溫度穩定性好、電容(rong)量精(jing)確(que)度高，常用在(zai)高頻振蕩電路中。

瓷(ci)介(jie)電(dian)(dian)(dian)(dian)(dian)容(rong)(rong)(rong)的(de)(de)介(jie)質是陶(tao)瓷(ci)，根據陶(tao)瓷(ci)成分不同可分為(wei)高頻(pin)瓷(ci)介(jie)電(dian)(dian)(dian)(dian)(dian)容(rong)(rong)(rong)和低(di)頻(pin)瓷(ci)介(jie)電(dian)(dian)(dian)(dian)(dian)容(rong)(rong)(rong)兩種（高頻(pin)的(de)(de)用(yong)CC表示，低(di)頻(pin)的(de)(de)用(yong)CT表示）。高頻(pin)瓷(ci)介(jie)電(dian)(dian)(dian)(dian)(dian)容(rong)(rong)(rong)容(rong)(rong)(rong)量(liang)在零(ling)點幾(ji)(ji)皮法(fa)(fa)至幾(ji)(ji)百皮法(fa)(fa)之間。常使用(yong)于要求損耗小、電(dian)(dian)(dian)(dian)(dian)容(rong)(rong)(rong)量(liang)穩(wen)定的(de)(de)場合和在高頻(pin)電(dian)(dian)(dian)(dian)(dian)路中(zhong)作調諧電(dian)(dian)(dian)(dian)(dian)容(rong)(rong)(rong)、振(zhen)蕩回路電(dian)(dian)(dian)(dian)(dian)容(rong)(rong)(rong)和溫度補償電(dian)(dian)(dian)(dian)(dian)容(rong)(rong)(rong)。電(dian)(dian)(dian)(dian)(dian)容(rong)(rong)(rong)耐壓有 160V、250V和 500V等幾(ji)(ji)種。容(rong)(rong)(rong)量(liang)誤(wu)差分為(wei)2%、5%、10%和20%幾(ji)(ji)種。低(di)頻(pin)瓷(ci)介(jie)電(dian)(dian)(dian)(dian)(dian)容(rong)(rong)(rong)容(rong)(rong)(rong)量(liang)從300pF到22000pF之間，適(shi)用(yong)于低(di)頻(pin)電(dian)(dian)(dian)(dian)(dian)路中(zhong)。

紙介電(dian)容生產工(gong)藝簡單(dan)，成本(ben)低，電(dian)壓(ya)范(fan)圍較寬；缺點是電(dian)容量(liang)不易控(kong)制，損耗較大，穩定性較差，電(dian)感最大，通常不適(shi)宜(yi)在高(gao)頻下使用。

滌(di)綸電(dian)(dian)(dian)容(rong)又叫聚酯電(dian)(dian)(dian)容(rong)。它是(shi)以滌(di)綸薄膜做介質的(de)電(dian)(dian)(dian)容(rong)。它可(ke)用(yong)于各種(zhong)電(dian)(dian)(dian)子儀器(qi)儀表，電(dian)(dian)(dian)視機(ji)、收錄機(ji)的(de)耦合、退(tui)耦、旁路、隔直流等電(dian)(dian)(dian)路中。

聚(ju)苯(ben)(ben)乙烯(xi)電(dian)(dian)容(rong)(rong)是(shi)(shi)(shi)以聚(ju)苯(ben)(ben)乙烯(xi)薄膜為介(jie)質制成(cheng)的(de)(de)電(dian)(dian)容(rong)(rong)。聚(ju)苯(ben)(ben)乙烯(xi)電(dian)(dian)容(rong)(rong)的(de)(de)最大(da)特(te)點是(shi)(shi)(shi)絕緣電(dian)(dian)阻高(gao)。這(zhe)種電(dian)(dian)容(rong)(rong)的(de)(de)高(gao)頻損耗(hao)小，電(dian)(dian)容(rong)(rong)量穩定，是(shi)(shi)(shi)目前應用廣泛的(de)(de)一(yi)種電(dian)(dian)容(rong)(rong)，由于其(qi)精(jing)度(du)高(gao)，在濾波器及對容(rong)(rong)量要(yao)求精(jing)確的(de)(de)電(dian)(dian)路中（如電(dian)(dian)子琴電(dian)(dian)路）多采(cai)用。它(ta)的(de)(de)缺點是(shi)(shi)(shi)工作溫度(du)范圍不(bu)寬，上限為+75℃。因此焊接時烙鐵(tie)的(de)(de)接觸時間(jian)不(bu)宜過(guo)長，以免因過(guo)熱(re)損壞薄膜。