一、什么是電子陶瓷材料
電(dian)(dian)(dian)(dian)子(zi)陶(tao)(tao)瓷是指(zhi)在(zai)電(dian)(dian)(dian)(dian)子(zi)工(gong)業中(zhong)能夠利用電(dian)(dian)(dian)(dian)、磁性質的(de)陶(tao)(tao)瓷,一般在(zai)電(dian)(dian)(dian)(dian)子(zi)設備當中(zhong),作為(wei)安裝(zhuang)、固(gu)定(ding)、支(zhi)撐(cheng)、保(bao)護、絕緣、隔離以及連接各種(zhong)無線電(dian)(dian)(dian)(dian)元件及器件的(de)材(cai)料。
電子陶瓷屬于無機多晶體,微觀(guan)結構上是介乎(hu)單品與玻璃之(zhi)間的一類物(wu)質,陶瓷內部之(zhi)間是由離子鍵和(he)共價鍵所結合(he),通過精(jing)密控制陶瓷的表面、晶界和(he)尺寸(cun)結構可以使陶瓷獲得新功能(neng),具有(you)高(gao)擦點(dian)、硬度高(gao)和(he)彈性模量大等(deng)特(te)點(dian),能(neng)夠耐高(gao)溫、磨損(sun)和(he)氧化腐(fu)蝕,化學(xue)穩定性好(hao),廣泛應用于光通信、無線通信、工業激光、消(xiao)費電(dian)子、汽車電(dian)子等(deng)領域。
二、電子陶瓷材料有哪些種類
電子(zi)陶瓷材料的種類(lei)眾(zhong)多,按(an)功能和用途不同,可分為(wei)五大類(lei):
1、絕緣裝置瓷
簡稱裝(zhuang)置瓷(ci)(ci),具有優良的(de)(de)電(dian)絕(jue)(jue)(jue)緣性能,用(yong)作電(dian)子(zi)設備和(he)(he)器(qi)件(jian)中的(de)(de)結構件(jian)、基片和(he)(he)外殼等的(de)(de)電(dian)子(zi)陶瓷(ci)(ci)。絕(jue)(jue)(jue)緣裝(zhuang)置瓷(ci)(ci)件(jian)包(bao)括各種絕(jue)(jue)(jue)緣子(zi)、線圈骨架、電(dian)子(zi)管(guan)座、波(bo)段開關、電(dian)容器(qi)支柱支架、集成電(dian)路(lu)基片和(he)(he)封(feng)裝(zhuang)外殼等。對這(zhe)類瓷(ci)(ci)的(de)(de)基本要(yao)求是(shi)介(jie)(jie)電(dian)常(chang)數ε低,介(jie)(jie)質損耗tanδ小,絕(jue)(jue)(jue)緣電(dian)阻率(lv)ρ高,擊(ji)穿(chuan)強(qiang)度E?大,介(jie)(jie)電(dian)溫度特性和(he)(he)頻率(lv)特性好(hao)。此外,還要(yao)求有較高的(de)(de)機械強(qiang)度和(he)(he)化學(xue)穩定性。
在(zai)這類陶瓷(ci)(ci)中以滑石瓷(ci)(ci)和(he)氧(yang)化(hua)鋁(lv)(lv)瓷(ci)(ci)應用(yong)(yong)最(zui)廣,滑石瓷(ci)(ci)的(de)(de)電(dian)(dian)(dian)絕緣(yuan)性(xing)(xing)優良且成本較低(di),是用(yong)(yong)于射電(dian)(dian)(dian)頻(pin)段內(nei)的(de)(de)典型高頻(pin)裝(zhuang)置瓷(ci)(ci)。氧(yang)化(hua)鋁(lv)(lv)瓷(ci)(ci)是一類電(dian)(dian)(dian)絕緣(yuan)性(xing)(xing)更佳的(de)(de)高頻(pin)、高溫、高強度裝(zhuang)置瓷(ci)(ci)。其電(dian)(dian)(dian)性(xing)(xing)能和(he)物理性(xing)(xing)能隨三氧(yang)化(hua)二鋁(lv)(lv)含量的(de)(de)增多而提(ti)高。常用(yong)(yong)的(de)(de)有含75%、95%、99%三氧(yang)化(hua)二鋁(lv)(lv)的(de)(de)高鋁(lv)(lv)氧(yang)瓷(ci)(ci)。在(zai)一些要求極高的(de)(de)集(ji)成電(dian)(dian)(dian)路(lu)中,甚至還使用(yong)(yong)三氧(yang)化(hua)二鋁(lv)(lv)含量達99.9%的(de)(de)純(chun)剛(gang)玉瓷(ci)(ci),其性(xing)(xing)質與藍寶石單晶相(xiang)近(jin)。高鋁(lv)(lv)氧(yang)瓷(ci)(ci),尤其是純(chun)剛(gang)玉瓷(ci)(ci)的(de)(de)缺點是制造困難,燒成溫度高、價格貴。
裝(zhuang)置瓷中還有一類以氧(yang)(yang)化(hua)鈹(BeO)為代表(biao)的(de)(de)高熱(re)(re)(re)導瓷。含BeO95%的(de)(de)氧(yang)(yang)化(hua)鈹瓷的(de)(de)室溫(wen)導熱(re)(re)(re)率(lv)與(yu)金屬相(xiang)同(tong)。氧(yang)(yang)化(hua)鈹還具有良好的(de)(de)介電性(xing)、耐溫(wen)度劇(ju)變性(xing)和(he)很高的(de)(de)機械強度。其(qi)缺點是BeO原料的(de)(de)毒性(xing)很大,瓷料燒成溫(wen)度高,因(yin)而限制了它的(de)(de)應用。氮(dan)化(hua)硼?(BN)瓷和(he)氮(dan)化(hua)鋁(AlN)瓷也(ye)屬于高熱(re)(re)(re)導瓷,其(qi)導熱(re)(re)(re)性(xing)雖不及氧(yang)(yang)化(hua)鈹瓷,但無毒,加工性(xing)能和(he)介電性(xing)能均(jun)好,可供高頻(pin)大功率(lv)晶體管(guan)和(he)大規(gui)模(mo)集成電路中作散(san)熱(re)(re)(re)及絕緣用。
2、電容器瓷
是(shi)用(yong)作電(dian)容器介質的(de)(de)電(dian)子陶瓷(ci)(ci),這類(lei)陶瓷(ci)(ci)用(yong)量最(zui)大(da)、規(gui)格品種也(ye)最(zui)多,主要的(de)(de)有高頻(pin)、低頻(pin)電(dian)容器瓷(ci)(ci)和半導體電(dian)容器瓷(ci)(ci):
(1)高頻電容器瓷:屬于(yu)Ⅰ類電容器瓷,主要用于(yu)制造高頻電路中的高穩定性(xing)陶瓷電容器和(he)溫度補償電容器。構成這類陶瓷的主要成分大多是(shi)堿(jian)土金(jin)屬或稀(xi)土金(jin)屬的鈦酸鹽和(he)以(yi)鈦酸鹽為基的固溶(rong)體。
(2)低頻電容器瓷:屬(shu)于Ⅱ類電容(rong)(rong)器(qi)瓷,主要用于制造低頻電路中(zhong)的(de)旁路、隔直(zhi)流和濾波用的(de)陶(tao)(tao)瓷電容(rong)(rong)器(qi)。主要特(te)點是介電常數ε?高,損耗(hao)角正切較(jiao)大且tanδ及ε隨溫度(du)的(de)變化(hua)率(lv)較(jiao)大。這類陶(tao)(tao)瓷中(zhong)應(ying)用最(zui)多的(de)是以鐵電鈦酸鋇(BaTiO3)為主成(cheng)分,通過摻雜(za)改性而得到的(de)高ε(室(shi)溫下(xia)可(ke)達20000)和ε的(de)溫度(du)變化(hua)率(lv)低的(de)瓷料(liao)。
(3)半導體電容器瓷:利用半導體化的(de)(de)陶(tao)瓷(ci)外表面(mian)或晶(jing)粒間的(de)(de)內表面(mian)(晶(jing)界(jie))上(shang)形成的(de)(de)絕(jue)緣層為(wei)電(dian)(dian)(dian)容(rong)器(qi)介(jie)質(zhi)的(de)(de)電(dian)(dian)(dian)子陶(tao)瓷(ci)。其中(zhong)利用陶(tao)瓷(ci)晶(jing)界(jie)層的(de)(de)介(jie)電(dian)(dian)(dian)性質(zhi)而制成的(de)(de)邊界(jie)層電(dian)(dian)(dian)容(rong)器(qi)是(shi)一(yi)類新型的(de)(de)高(gao)(gao)(gao)(gao)性能(neng)、高(gao)(gao)(gao)(gao)可靠(kao)的(de)(de)電(dian)(dian)(dian)容(rong)器(qi),它的(de)(de)介(jie)電(dian)(dian)(dian)損耗(hao)小、絕(jue)緣電(dian)(dian)(dian)阻及工作電(dian)(dian)(dian)壓高(gao)(gao)(gao)(gao)。這種陶(tao)瓷(ci)的(de)(de)視在(zai)介(jie)電(dian)(dian)(dian)常數極高(gao)(gao)(gao)(gao)(可達105以上(shang))、介(jie)質(zhi)損耗(hao)小(小于(yu)(yu)1%)、體電(dian)(dian)(dian)阻率(lv)高(gao)(gao)(gao)(gao)(高(gao)(gao)(gao)(gao)于(yu)(yu)1011歐·厘米)、介(jie)質(zhi)色(se)散頻率(lv)高(gao)(gao)(gao)(gao)(高(gao)(gao)(gao)(gao)于(yu)(yu)1吉赫)、抗潮性好,是(shi)一(yi)種高(gao)(gao)(gao)(gao)性能(neng)、高(gao)(gao)(gao)(gao)穩定的(de)(de)電(dian)(dian)(dian)容(rong)器(qi)介(jie)質(zhi)。
3、鐵電陶瓷
是以鐵電(dian)(dian)(dian)性(xing)晶體為主晶相的電(dian)(dian)(dian)子(zi)陶(tao)瓷(ci),利(li)用其壓(ya)電(dian)(dian)(dian)特(te)性(xing)可以制成壓(ya)電(dian)(dian)(dian)器件,這是鐵電(dian)(dian)(dian)陶(tao)瓷(ci)的主要(yao)應(ying)用,因而常(chang)把鐵電(dian)(dian)(dian)陶(tao)瓷(ci)稱(cheng)為壓(ya)電(dian)(dian)(dian)陶(tao)瓷(ci)。利(li)用鐵電(dian)(dian)(dian)陶(tao)瓷(ci)的熱釋電(dian)(dian)(dian)特(te)性(xing)(在溫(wen)(wen)(wen)度變化(hua)(hua)時,因極化(hua)(hua)強度的變化(hua)(hua)而在鐵電(dian)(dian)(dian)體表面釋放電(dian)(dian)(dian)荷(he)的效應(ying))可以制成紅外探測(ce)器件,在測(ce)溫(wen)(wen)(wen)、控溫(wen)(wen)(wen)、遙測(ce)、遙感以至生物、醫(yi)學(xue)等領域均有重要(yao)應(ying)用價值。
利用(yong)透明鐵電(dian)(dian)(dian)陶瓷PLZT(摻鑭(lan)的(de)鈦鋯酸鉛(qian))的(de)強電(dian)(dian)(dian)光(guang)(guang)效應(通過外加電(dian)(dian)(dian)場對透明鐵電(dian)(dian)(dian)陶瓷電(dian)(dian)(dian)疇狀態(tai)的(de)控制而(er)改變(bian)其光(guang)(guang)學性質,從而(er)表現(xian)出電(dian)(dian)(dian)控雙折射和電(dian)(dian)(dian)控光(guang)(guang)散射的(de)效應),可以(yi)(yi)制成激(ji)光(guang)(guang)調制器(qi)(qi)、光(guang)(guang)電(dian)(dian)(dian)顯示(shi)器(qi)(qi)、光(guang)(guang)信息存儲器(qi)(qi)、光(guang)(guang)開關(guan)、光(guang)(guang)電(dian)(dian)(dian)傳(chuan)感器(qi)(qi)、圖(tu)像(xiang)存儲和顯示(shi)器(qi)(qi),以(yi)(yi)及激(ji)光(guang)(guang)或核輻射防護鏡等新型器(qi)(qi)件(jian)。
4、半導體陶瓷
通過半(ban)導(dao)體(ti)(ti)化措施使(shi)陶瓷(ci)具有半(ban)導(dao)電(dian)性(xing)(xing)晶粒和絕(jue)緣(yuan)性(xing)(xing)(或半(ban)導(dao)體(ti)(ti)性(xing)(xing))晶界,從而呈現很強的界面(mian)勢壘等半(ban)導(dao)體(ti)(ti)特性(xing)(xing)的電(dian)子陶瓷(ci)。
半導(dao)體(ti)陶瓷(ci)種(zhong)類很多,其中包括(kuo)利(li)用(yong)半導(dao)體(ti)瓷(ci)中晶粒本(ben)身性(xing)質制(zhi)成(cheng)的(de)各種(zhong)負溫(wen)度系數熱敏(min)電(dian)(dian)(dian)阻(zu)(zu);利(li)用(yong)晶界性(xing)質制(zhi)成(cheng)的(de)半導(dao)體(ti)電(dian)(dian)(dian)容器、ZnO?壓敏(min)電(dian)(dian)(dian)阻(zu)(zu)器、BaTiO3系正溫(wen)度系數熱敏(min)電(dian)(dian)(dian)阻(zu)(zu)器、CdS/Cu2S太陽能電(dian)(dian)(dian)池;以及(ji)利(li)用(yong)表面性(xing)質制(zhi)成(cheng)的(de)各種(zhong)陶瓷(ci)型濕(shi)敏(min)電(dian)(dian)(dian)阻(zu)(zu)器和(he)氣敏(min)電(dian)(dian)(dian)阻(zu)(zu)器等。
5、離子陶瓷
快離子導電的電子陶瓷,具有(you)快(kuai)速傳遞正離子(zi)(zi)的(de)特性,典型代(dai)表(biao)是(shi)β-Al2O3瓷。這(zhe)種陶瓷在300℃下離子(zi)(zi)電(dian)導率(lv)可達0.1/(歐·厘米(mi)),可用來制作(zuo)較經濟的(de)高(gao)(gao)比率(lv)能量的(de)固體電(dian)池,還可制作(zuo)緩慢(man)放電(dian)的(de)高(gao)(gao)儲(chu)能密(mi)度的(de)電(dian)容器,它(ta)是(shi)有(you)助于解決能源問題的(de)材料(liao)。