如何觀(guan)看(kan)工控主板的做工質量(liang)?下面一起來學習下吧。

　　一、布線設計

　　工(gong)控(kong)主(zhu)(zhu)板(ban)(ban)(ban)上(shang)的(de)(de)(de)(de)(de)布(bu)(bu)(bu)(bu)線(xian)(xian)(xian)(xian)(xian)(xian)設(she)計(ji)是(shi)一(yi)門比較(jiao)專業的(de)(de)(de)(de)(de)學問，它(ta)要視不(bu)(bu)(bu)(bu)(bu)同(tong)的(de)(de)(de)(de)(de)線(xian)(xian)(xian)(xian)(xian)(xian)路(lu)(lu)特性進(jin)行(xing)(xing)(xing)不(bu)(bu)(bu)(bu)(bu)同(tong)的(de)(de)(de)(de)(de)設(she)計(ji)處(chu)理方式。工(gong)控(kong)主(zhu)(zhu)板(ban)(ban)(ban)上(shang)采用(yong)的(de)(de)(de)(de)(de)"蛇(she)(she)行(xing)(xing)(xing)布(bu)(bu)(bu)(bu)線(xian)(xian)(xian)(xian)(xian)(xian)"就很有(you)講究，有(you)些人(ren)認為(wei)蛇(she)(she)行(xing)(xing)(xing)布(bu)(bu)(bu)(bu)線(xian)(xian)(xian)(xian)(xian)(xian)越多(duo)就說(shuo)明有(you)更高的(de)(de)(de)(de)(de)設(she)計(ji)水平，這種觀(guan)點是(shi)錯誤的(de)(de)(de)(de)(de)。采用(yong)蛇(she)(she)行(xing)(xing)(xing)布(bu)(bu)(bu)(bu)線(xian)(xian)(xian)(xian)(xian)(xian)的(de)(de)(de)(de)(de)原(yuan)因有(you)兩個(ge)：一(yi)個(ge)是(shi)為(wei)了保證(zheng)布(bu)(bu)(bu)(bu)線(xian)(xian)(xian)(xian)(xian)(xian)線(xian)(xian)(xian)(xian)(xian)(xian)路(lu)(lu)的(de)(de)(de)(de)(de)等長(chang)(chang)，因為(wei)像CPU到北橋芯片的(de)(de)(de)(de)(de)時(shi)鐘線(xian)(xian)(xian)(xian)(xian)(xian)，它(ta)不(bu)(bu)(bu)(bu)(bu)同(tong)于普通電器上(shang)的(de)(de)(de)(de)(de)線(xian)(xian)(xian)(xian)(xian)(xian)路(lu)(lu)，在這些線(xian)(xian)(xian)(xian)(xian)(xian)路(lu)(lu)上(shang)以(yi)(yi)100MHz左右的(de)(de)(de)(de)(de)頻(pin)率高速運行(xing)(xing)(xing)的(de)(de)(de)(de)(de)信(xin)號對線(xian)(xian)(xian)(xian)(xian)(xian)路(lu)(lu)的(de)(de)(de)(de)(de)長(chang)(chang)度(du)十(shi)分的(de)(de)(de)(de)(de)敏(min)感,不(bu)(bu)(bu)(bu)(bu)等長(chang)(chang)的(de)(de)(de)(de)(de)時(shi)鐘布(bu)(bu)(bu)(bu)線(xian)(xian)(xian)(xian)(xian)(xian)路(lu)(lu)會引起信(xin)號的(de)(de)(de)(de)(de)不(bu)(bu)(bu)(bu)(bu)同(tong)步進(jin)而造成系(xi)統不(bu)(bu)(bu)(bu)(bu)穩,這樣某(mou)些線(xian)(xian)(xian)(xian)(xian)(xian)路(lu)(lu)需要以(yi)(yi)彎曲的(de)(de)(de)(de)(de)方式走線(xian)(xian)(xian)(xian)(xian)(xian),以(yi)(yi)調(diao)節長(chang)(chang)度(du);另(ling)一(yi)個(ge)使用(yong)蛇(she)(she)行(xing)(xing)(xing)布(bu)(bu)(bu)(bu)線(xian)(xian)(xian)(xian)(xian)(xian)的(de)(de)(de)(de)(de)常(chang)見(jian)原(yuan)因是(shi)為(wei)了盡(jin)可(ke)能減少電磁輻射(EMI)對主(zhu)(zhu)板(ban)(ban)(ban)其余部(bu)件(jian)和人(ren)體的(de)(de)(de)(de)(de)影響，因為(wei)高速而單調(diao)的(de)(de)(de)(de)(de)數字(zi)信(xin)號會大(da)大(da)地(di)干擾主(zhu)(zhu)板(ban)(ban)(ban)上(shang)模擬器件(jian)的(de)(de)(de)(de)(de)工(gong)作，如AC''97芯片或板(ban)(ban)(ban)載(zai)的(de)(de)(de)(de)(de)軟貓等。平常(chang)抑(yi)制EMI的(de)(de)(de)(de)(de)一(yi)種簡便方法就是(shi)通過(guo)設(she)計(ji)蛇(she)(she)形布(bu)(bu)(bu)(bu)線(xian)(xian)(xian)(xian)(xian)(xian)，來盡(jin)可(ke)能多(duo)吸收消化輻射。采用(yong)蛇(she)(she)行(xing)(xing)(xing)布(bu)(bu)(bu)(bu)線(xian)(xian)(xian)(xian)(xian)(xian)有(you)了上(shang)面(mian)這些好(hao)(hao)處(chu)，并(bing)(bing)不(bu)(bu)(bu)(bu)(bu)是(shi)說(shuo)在工(gong)控(kong)主(zhu)(zhu)板(ban)(ban)(ban)布(bu)(bu)(bu)(bu)線(xian)(xian)(xian)(xian)(xian)(xian)設(she)計(ji)的(de)(de)(de)(de)(de)時(shi)候(hou)使用(yong)蛇(she)(she)行(xing)(xing)(xing)布(bu)(bu)(bu)(bu)線(xian)(xian)(xian)(xian)(xian)(xian)越多(duo)越好(hao)(hao)，因為(wei)過(guo)多(duo)過(guo)密的(de)(de)(de)(de)(de)主(zhu)(zhu)板(ban)(ban)(ban)布(bu)(bu)(bu)(bu)線(xian)(xian)(xian)(xian)(xian)(xian)會造成工(gong)控(kong)主(zhu)(zhu)板(ban)(ban)(ban)布(bu)(bu)(bu)(bu)局的(de)(de)(de)(de)(de)疏密不(bu)(bu)(bu)(bu)(bu)均，會對工(gong)控(kong)主(zhu)(zhu)板(ban)(ban)(ban)的(de)(de)(de)(de)(de)質量有(you)一(yi)定的(de)(de)(de)(de)(de)影響。好(hao)(hao)的(de)(de)(de)(de)(de)布(bu)(bu)(bu)(bu)線(xian)(xian)(xian)(xian)(xian)(xian)應(ying)使工(gong)控(kong)主(zhu)(zhu)板(ban)(ban)(ban)上(shang)各部(bu)分線(xian)(xian)(xian)(xian)(xian)(xian)路(lu)(lu)密度(du)差別不(bu)(bu)(bu)(bu)(bu)大(da)，并(bing)(bing)且要盡(jin)可(ke)能均勻(yun)分布(bu)(bu)(bu)(bu)否則很容易造成工(gong)控(kong)主(zhu)(zhu)板(ban)(ban)(ban)的(de)(de)(de)(de)(de)不(bu)(bu)(bu)(bu)(bu)穩定。

　　二(er)、做工用料

　　1、PCB(印刷電路板)的(de)做工

　　質(zhi)(zhi)量(liang)有(you)保證的PC板(ban)色彩基本保持一致，光潔度(du)好(hao)，看起(qi)來油(you)光發(fa)亮的一般(ban)質(zhi)(zhi)量(liang)就比較好(hao)。PCB板(ban)層(ceng)(ceng)數一般(ban)的標(biao)準是(shi)4、6層(ceng)(ceng)板(ban)，當然6層(ceng)(ceng)板(ban)質(zhi)(zhi)量(liang)要(yao)好(hao)很多。

　　2、SMT(表(biao)面(mian)貼裝)元(yuan)器件(jian)的做(zuo)工

　　主要(yao)通過觀(guan)察某些元器(qi)(qi)件貼裝精度來判定主板(ban)的生(sheng)產工藝(yi)是否(fou)精良(liang)，標(biao)準的元器(qi)(qi)件貼裝定位準確，沒有偏移。

　　3、工控主板(ban)用(yong)料

　　名牌大(da)廠所生產(chan)的(de)工控主(zhu)板用(yong)料，像CPU插(cha)座、擴展槽和插(cha)槽等都采用(yong)名廠的(de)插(cha)接界(jie)面元器件，主(zhu)板的(de)性能也就不用(yong)多說(shuo)了。