來(lai)看下雙面(mian)(mian)(mian)混裝(zhuang)工(gong)(gong)(gong)藝(yi)(yi)，這種(zhong)工(gong)(gong)(gong)藝(yi)(yi)師要(yao)兩面(mian)(mian)(mian)都需要(yao)貼(tie)片的，本溪電(dian)路(lu)(lu)板(ban)加(jia)工(gong)(gong)(gong)，一(yi)步就(jiu)是(shi)來(lai)料的檢查，SMT電(dian)路(lu)(lu)板(ban)加(jia)工(gong)(gong)(gong)樣板(ban)，這是(shi)所以加(jia)工(gong)(gong)(gong)工(gong)(gong)(gong)藝(yi)(yi)的步驟，然(ran)后PCB的B面(mian)(mian)(mian)進行點貼(tie)片，B面(mian)(mian)(mian)需要(yao)固化，然(ran)后就(jiu)是(shi)翻板(ban)，B面(mian)(mian)(mian)的工(gong)(gong)(gong)藝(yi)(yi)已經完成，接下來(lai)就(jiu)是(shi)PCB的A面(mian)(mian)(mian)插件(jian)，A面(mian)(mian)(mian)波峰(feng)焊(han)，清洗，后一(yi)道工(gong)(gong)(gong)序就(jiu)是(shi)檢測，如果合格直接包裝(zhuang)，如果不(bu)合格進行返修，smt電(dian)路(lu)(lu)板(ban)加(jia)工(gong)(gong)(gong)組裝(zhuang)，在(zai)整個過程當中(zhong)一(yi)定(ding)要(yao)注意事行貼(tie)，然(ran)后再進行擦，smt電(dian)路(lu)(lu)板(ban)加(jia)工(gong)(gong)(gong)價格，這種(zhong)工(gong)(gong)(gong)藝(yi)(yi)一(yi)般都是(shi)適用(yong)于一(yi)些分(fen)離性的元件(jian)的。

電子元件表面(mian)貼(tie)裝加(jia)工(gong)時需要注意(yi)哪些事(shi)項呢？我們來為大家簡要介紹下：首先要注意(yi)模(mo)板(ban)(ban)(ban)的問題：首先根據所(suo)設計的PCB加(jia)工(gong)模(mo)板(ban)(ban)(ban)。一般模(mo)板(ban)(ban)(ban)分為化學(xue)腐蝕(shi)（也稱蝕(shi)刻）銅模(mo)板(ban)(ban)(ban)或不銹(xiu)鋼模(mo)板(ban)(ban)(ban)（價(jia)格低，適用(yong)于小批(pi)(pi)量、試驗且芯(xin)片引腳(jiao)間(jian)距>0.65mm）；激光切割不銹(xiu)鋼模(mo)板(ban)(ban)(ban)（精度高(gao)、價(jia)格高(gao)，適用(yong)于大批(pi)(pi)量、自動生產線且0.3mm≤芯(xin)片引腳(jiao)間(jian)距≤0.5mm）。

接(jie)收端差分(fen)線對(dui)之間可否加一(yi)匹配電阻？

接(jie)收端差分線對(dui)間(jian)的(de)匹配電阻通常會加， 其值(zhi)應等于差分阻抗的(de)值(zhi)。這樣(yang)信號品質(zhi)會好些。

為何差分對(dui)的布線要(yao)靠近且平行？

對差(cha)(cha)(cha)(cha)分對的布線(xian)方式應該要(yao)(yao)適當(dang)的靠(kao)近且平行。所(suo)謂適當(dang)的靠(kao)近是因為這間(jian)距會影響(xiang)到差(cha)(cha)(cha)(cha)分阻(zu)抗(differential impedance)的值， 此值是設計差(cha)(cha)(cha)(cha)分對的重要(yao)(yao)參數。需要(yao)(yao)平行也(ye)是因為要(yao)(yao)保持差(cha)(cha)(cha)(cha)分阻(zu)抗的一(yi)致性。若兩(liang)線(xian)忽(hu)遠忽(hu)近， 差(cha)(cha)(cha)(cha)分阻(zu)抗就會不一(yi)致， 就會影響(xiang)信號完整性(signal integrity)及(ji)時間(jian)延遲(timing delay)。