在電(dian)子產品制造(zao)中，靜電(dian)放電(dian)往往會損傷器(qi)件(jian)，甚至使器(qi)件(jian)失效，造(zao)成(cheng)嚴重損失，因此二(er)手貼片(pian)機(ji)(ji)生產中的靜電(dian)防護非常(chang)重要(yao)。帶您了解二(er)手貼片(pian)機(ji)(ji)防靜電(dian)的相(xiang)關知(zhi)識。

一、靜(jing)電和(he)靜(jing)電的危害(hai)

靜(jing)電(dian)(dian)是一種電(dian)(dian)能(neng)，它存留于物體(ti)表面，是正負電(dian)(dian)荷在局部范圍內失去平衡的(de)結果，通過電(dian)(dian)子(zi)或離子(zi)的(de)轉(zhuan)換而(er)形成的(de)。靜(jing)電(dian)(dian)現(xian)象(xiang)是電(dian)(dian)荷在產生和消失過程中(zhong)產生的(de)電(dian)(dian)現(xian)象(xiang)的(de)總稱。如摩擦起(qi)電(dian)(dian)、人體(ti)起(qi)電(dian)(dian)等現(xian)象(xiang)。  

隨(sui)著(zhu)科技發展，靜(jing)電(dian)(dian)(dian)(dian)現象已在(zai)(zai)靜(jing)電(dian)(dian)(dian)(dian)噴涂、靜(jing)電(dian)(dian)(dian)(dian)紡(fang)織、靜(jing)電(dian)(dian)(dian)(dian)分選、靜(jing)電(dian)(dian)(dian)(dian)成(cheng)像等領域(yu)得到廣泛的有效應(ying)用。但(dan)在(zai)(zai)另(ling)一方面，靜(jing)電(dian)(dian)(dian)(dian)的產(chan)生在(zai)(zai)許多領域(yu)會(hui)帶來重大危害和損 失。在(zai)(zai)電(dian)(dian)(dian)(dian)子(zi)工業中，隨(sui)著(zhu)集成(cheng)度越(yue)來越(yue)高，集成(cheng)電(dian)(dian)(dian)(dian)路的內絕緣層(ceng)越(yue)來越(yue)薄，互連導線寬度與間距越(yue)來越(yue)小，例如CMOS器(qi)件(jian)絕緣層(ceng)的典(dian)型厚度約為0．1μm，其 相應(ying)耐擊(ji)(ji)穿電(dian)(dian)(dian)(dian)壓在(zai)(zai)80-100V；VMOS器(qi)件(jian)的絕緣層(ceng)更(geng)薄，擊(ji)(ji)穿電(dian)(dian)(dian)(dian)壓在(zai)(zai)30V。而在(zai)(zai)電(dian)(dian)(dian)(dian)子(zi)產(chan)品(pin)制造中以(yi)及運輸(shu)、存儲(chu)等過程中所(suo)產(chan)生的靜(jing)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)壓遠遠超過 MOS器(qi)件(jian)的擊(ji)(ji)穿電(dian)(dian)(dian)(dian)壓，往往會(hui)使器(qi)件(jian)產(chan)生硬擊(ji)(ji)穿或軟擊(ji)(ji)穿(器(qi)件(jian)局部損傷)現象，使其失效或嚴重影(ying)響產(chan)品(pin)的可靠性。  

二、靜電敏感器件

對(dui)靜(jing)(jing)電(dian)反(fan)應敏(min)感(gan)的器(qi)(qi)(qi)件(jian)(jian)稱為靜(jing)(jing)電(dian)敏(min)感(gan)元器(qi)(qi)(qi)件(jian)(jian)(SSD)。靜(jing)(jing)電(dian)敏(min)感(gan)器(qi)(qi)(qi)件(jian)(jian)主要是指超大規模集成(cheng)電(dian)路，特(te)別是金屬化膜半(ban)導體(ti)(MOS電(dian)路)。可(ke)根據SSD分級表，針(zhen)對(dui)不同(tong)的SSD器(qi)(qi)(qi)件(jian)(jian)，采取不同(tong)的靜(jing)(jing)電(dian)防護措施。

三、電(dian)子(zi)產品制造中(zhong)的靜(jing)電(dian)源  

1.人(ren)(ren)體(ti)的(de)(de)活(huo)動，人(ren)(ren)與(yu)衣服、鞋、襪等物體(ti)之間(jian)的(de)(de)摩擦、接觸和分離等產(chan)(chan)生(sheng)(sheng)的(de)(de)靜電(dian)(dian)(dian)是電(dian)(dian)(dian)子產(chan)(chan)品制造中主要靜電(dian)(dian)(dian)源之一。人(ren)(ren)體(ti)靜電(dian)(dian)(dian)是導致(zhi)器(qi)件產(chan)(chan)生(sheng)(sheng)硬擊穿的(de)(de)主要原因。人(ren)(ren)體(ti)活(huo)動產(chan)(chan)生(sheng)(sheng)的(de)(de)靜電(dian)(dian)(dian)電(dian)(dian)(dian)壓(ya)約0.5-2KV。另(ling)外(wai)空氣濕度對(dui)靜電(dian)(dian)(dian)電(dian)(dian)(dian)壓(ya)影響很大，若在干燥環境中還要上升1個數量級。相對(dui)濕度對(dui)與(yu)人(ren)(ren)體(ti)活(huo)動帶(dai) 電(dian)(dian)(dian)的(de)(de)關系，人(ren)(ren)體(ti)帶(dai)電(dian)(dian)(dian)后(hou)觸摸到地線(xian)，會產(chan)(chan)生(sheng)(sheng)放(fang)電(dian)(dian)(dian)現象，人(ren)(ren)體(ti)就(jiu)會產(chan)(chan)生(sheng)(sheng)不同程度的(de)(de)電(dian)(dian)(dian)擊感(gan)反應，其反應的(de)(de)程度稱(cheng)為電(dian)(dian)(dian)擊感(gan)度。

2.化纖或棉制工作(zuo)服(fu)與(yu)工作(zuo)臺(tai)面、坐椅(yi)摩(mo)擦時(shi)，可(ke)在服(fu)裝表面產(chan)生6000V以上的靜電(dian)電(dian)壓，并(bing)使(shi)人體(ti)帶電(dian)，此時(shi)與(yu)器件接(jie)觸時(shi)，會(hui)導致放(fang)電(dian)，容易損壞器件。

3.橡膠或塑料鞋底的絕(jue)緣電(dian)阻(zu)高(gao)達(da)1013Ω，當與(yu)地面摩擦時產生靜電(dian)，并使人體帶(dai)電(dian)。