?? 電子元件的防靜電損壞措施.htm
字號:
@list l30:level1
{mso-level-number-format:bullet;
mso-level-text:\F0B7;
mso-level-tab-stop:36.0pt;
mso-level-number-position:left;
text-indent:-18.0pt;
mso-ansi-font-size:10.0pt;
font-family:Symbol;}
@list l31
{mso-list-id:1834566202;
mso-list-type:hybrid;
mso-list-template-ids:-1219185128 660760236 1294736984 -1742163844 605702906 -1286182618 1968084126 -42037116 -1568248648 1412747504;}
@list l31:level1
{mso-level-number-format:bullet;
mso-level-text:\F0B7;
mso-level-tab-stop:36.0pt;
mso-level-number-position:left;
text-indent:-18.0pt;
mso-ansi-font-size:10.0pt;
font-family:Symbol;}
@list l32
{mso-list-id:1849444604;
mso-list-type:hybrid;
mso-list-template-ids:1308910158 -643259686 901030258 1150327316 -1849543064 -1166911100 -2116879946 1454924046 -392264706 1023456380;}
@list l32:level1
{mso-level-number-format:bullet;
mso-level-text:\F0B7;
mso-level-tab-stop:36.0pt;
mso-level-number-position:left;
text-indent:-18.0pt;
mso-ansi-font-size:10.0pt;
font-family:Symbol;}
@list l33
{mso-list-id:2002540127;
mso-list-type:hybrid;
mso-list-template-ids:1789024468 1038938856 1777770884 -1352487270 -462404862 -95245100 -813151704 1862857372 -850768144 -632623408;}
@list l34
{mso-list-id:2124839724;
mso-list-type:hybrid;
mso-list-template-ids:638631054 1141397762 1001023870 -1581505214 -588749148 646250444 -655740310 1558995980 -1613578812 -1578191092;}
@list l34:level1
{mso-level-number-format:alpha-upper;
mso-level-tab-stop:36.0pt;
mso-level-number-position:left;
text-indent:-18.0pt;}
@list l35
{mso-list-id:2136560237;
mso-list-type:hybrid;
mso-list-template-ids:-661376054 1247073928 -978817216 1740687950 -1304372222 -1029001126 117978396 -485449636 1968620436 2084974536;}
@list l35:level1
{mso-level-number-format:bullet;
mso-level-text:\F0B7;
mso-level-tab-stop:36.0pt;
mso-level-number-position:left;
text-indent:-18.0pt;
mso-ansi-font-size:10.0pt;
font-family:Symbol;}
@list l36
{mso-list-id:2142847828;
mso-list-type:hybrid;
mso-list-template-ids:1995069480 1646557374 -1813375514 1924685656 1120672130 438968288 440576932 1400647834 -46355370 -82290690;}
@list l36:level1
{mso-level-number-format:bullet;
mso-level-text:\F0B7;
mso-level-tab-stop:36.0pt;
mso-level-number-position:left;
text-indent:-18.0pt;
mso-ansi-font-size:10.0pt;
font-family:Symbol;}
ol
{margin-bottom:0cm;}
ul
{margin-bottom:0cm;}
-->
</style>
</head>
<body lang=ZH-CN link=blue vlink=blue style='tab-interval:21.0pt;text-justify-trim:
punctuation'>
<div class=Section1 style='layout-grid:15.6pt'>
<table border=0 cellspacing=0 cellpadding=0 width="100%" style='width:100.0%;
mso-cellspacing:0cm;mso-padding-alt:0cm 0cm 0cm 0cm'>
<tr>
<td valign=bottom style='background:#FFE6D2;padding:0cm 0cm 0cm 0cm'>
<p style='margin-right:36.0pt;margin-left:36.0pt'><span lang=EN-US
style='mso-bidi-font-family:Arial'><br>
<!--[if gte vml 1]><v:shapetype id="_x0000_t75" coordsize="21600,21600"
o:spt="75" o:preferrelative="t" path="m@4@5l@4@11@9@11@9@5xe" filled="f"
stroked="f">
<v:stroke joinstyle="miter"/>
<v:formulas>
<v:f eqn="if lineDrawn pixelLineWidth 0"/>
<v:f eqn="sum @0 1 0"/>
<v:f eqn="sum 0 0 @1"/>
<v:f eqn="prod @2 1 2"/>
<v:f eqn="prod @3 21600 pixelWidth"/>
<v:f eqn="prod @3 21600 pixelHeight"/>
<v:f eqn="sum @0 0 1"/>
<v:f eqn="prod @6 1 2"/>
<v:f eqn="prod @7 21600 pixelWidth"/>
<v:f eqn="sum @8 21600 0"/>
<v:f eqn="prod @7 21600 pixelHeight"/>
<v:f eqn="sum @10 21600 0"/>
</v:formulas>
<v:path o:extrusionok="f" gradientshapeok="t" o:connecttype="rect"/>
<o:lock v:ext="edit" aspectratio="t"/>
</v:shapetype><v:shape id="_x0000_i1025" type="#_x0000_t75" alt="" style='width:300pt;
height:30pt'>
<v:imagedata src="./電子元件的防靜電損壞措施.files/image001.gif" o:href="http://10.15.163.14/contents/TrainingResource/ebook/no6/imgs/tm2.gif"/>
</v:shape><![endif]--><![if !vml]><img width=400 height=40
src="./電子元件的防靜電損壞措施.files/image001.gif" border=0
tppabs="http://www.emcdoc.com.cn/ebook/no6/imgs/tm2.gif" v:shapes="_x0000_i1025"><![endif]><o:p></o:p></span></p>
</td>
</tr>
</table>
<p class=MsoNormal align=center style='text-align:center'><span lang=EN-US
style='font-size:15.0pt;display:none;mso-hide:all'><![if !supportEmptyParas]> <![endif]><o:p></o:p></span></p>
<div align=center>
<table border=1 cellspacing=0 cellpadding=0 width="100%" style='width:100.0%;
mso-cellspacing:0cm;border:none;mso-padding-alt:0cm 0cm 0cm 0cm'>
<tr>
<td style='border:none;background:#FFE6D2;padding:0cm 0cm 0cm 0cm'>
<div align=center>
<table border=0 cellspacing=0 cellpadding=0 width="90%" bgcolor="#ffffdf"
style='width:90.0%;mso-cellspacing:0cm;background:#FFFFDF;border:outset green .75pt;
mso-padding-alt:0cm 0cm 0cm 0cm'>
<tr>
<td width="100%" style='width:100.0%;border:inset green .75pt;padding:0cm 0cm 0cm 0cm'>
<p class=MsoNormal style='line-height:14.0pt'><span lang=EN-US
style='font-size:9.0pt;font-family:Arial'><br>
</span><span style='font-size:9.0pt;font-family:宋體;mso-ascii-font-family:
Arial;mso-hansi-font-family:Arial;mso-bidi-font-family:Arial'>１．靜電放電</span><span
lang=EN-US style='font-size:9.0pt;font-family:Arial'> <br>
</span><span style='font-size:9.0pt;font-family:宋體;mso-ascii-font-family:
Arial;mso-hansi-font-family:Arial;mso-bidi-font-family:Arial'> 靜電放電（</span><span
lang=EN-US style='font-size:9.0pt;font-family:Arial'>ESD</span><span
style='font-size:9.0pt;font-family:宋體;mso-ascii-font-family:Arial;
mso-hansi-font-family:Arial;mso-bidi-font-family:Arial'>）是大家熟知的電磁兼容問題，它可引起電子設備失靈或使其損壞。當半導體器件單獨放置或裝入電路模塊時，即使沒有加電，也可能造成這些器件的永久性損壞。對靜電放電敏感的元件被稱為靜電放電敏感元件（</span><span
lang=EN-US style='font-size:9.0pt;font-family:Arial'>ESDS</span><span
style='font-size:9.0pt;font-family:宋體;mso-ascii-font-family:Arial;
mso-hansi-font-family:Arial;mso-bidi-font-family:Arial'>）。</span><span
lang=EN-US style='font-size:9.0pt;font-family:Arial'><br>
</span><span style='font-size:9.0pt;font-family:宋體;mso-ascii-font-family:
Arial;mso-hansi-font-family:Arial;mso-bidi-font-family:Arial'> 如果一個元件的兩個針腳或更多針腳之間的電壓超過元件介質的擊穿強度，就會對元件造成損壞。這是</span><span
lang=EN-US style='font-size:9.0pt;font-family:Arial'>MOS</span><span
style='font-size:9.0pt;font-family:宋體;mso-ascii-font-family:Arial;
mso-hansi-font-family:Arial;mso-bidi-font-family:Arial'>器件出現(xiàn)故障最主要的原因。氧化層越薄，則元件對靜電放電的敏感性也越大。故障通常表現(xiàn)為元件本身對電源有一定阻值的短路現(xiàn)象。對于雙極性元件，損壞一般發(fā)生在薄氧化層隔開的已進行金屬噴鍍的有源半導體區(qū)域，因此會產生泄漏嚴重的路徑。</span><span
lang=EN-US style='font-size:9.0pt;font-family:Arial'><br>
</span><span style='font-size:9.0pt;font-family:宋體;mso-ascii-font-family:
Arial;mso-hansi-font-family:Arial;mso-bidi-font-family:Arial'> 另一種故障是由于節(jié)點的溫度超過半導體硅的熔點（</span><span
lang=EN-US style='font-size:9.0pt;font-family:Arial'>1415</span><span
style='font-size:9.0pt;font-family:宋體;mso-ascii-font-family:Arial;
mso-hansi-font-family:Arial;mso-bidi-font-family:Arial'>℃）時所引起的。靜電放電脈沖的能量可以產生局部地方發(fā)熱，因此出現(xiàn)這種機理的故障。即使電壓低于介質的擊穿電壓，也會發(fā)生這種故障。一個典型的例子是，</span><span
lang=EN-US style='font-size:9.0pt;font-family:Arial'>NPN</span><span
style='font-size:9.0pt;font-family:宋體;mso-ascii-font-family:Arial;
mso-hansi-font-family:Arial;mso-bidi-font-family:Arial'>型三極管發(fā)射極與基極間的擊穿會使電流增益急劇降低。</span><span
lang=EN-US style='font-size:9.0pt;font-family:Arial'><br>
</span><span style='font-size:9.0pt;font-family:宋體;mso-ascii-font-family:
Arial;mso-hansi-font-family:Arial;mso-bidi-font-family:Arial'> 器件受到靜電放電的影響后，也可能不立即出現(xiàn)功能性的損壞。這些受到潛在損壞的元件通常被稱為“跛腳”，一旦加以使用，將會對以后發(fā)生的靜電放電或傳導性瞬態(tài)表現(xiàn)出更大的敏感性。</span><span
lang=EN-US style='font-size:9.0pt;font-family:Arial'><br>
</span><span style='font-size:9.0pt;font-family:宋體;mso-ascii-font-family:
Arial;mso-hansi-font-family:Arial;mso-bidi-font-family:Arial'> 要密切注意元件在不易察覺的放電電壓下發(fā)生的損壞，這一點非常重要。人體有感覺的靜電放電電壓在</span><span
lang=EN-US style='font-size:9.0pt;font-family:Arial'>3000 — 5000V</span><span
style='font-size:9.0pt;font-family:宋體;mso-ascii-font-family:Arial;
mso-hansi-font-family:Arial;mso-bidi-font-family:Arial'>之間，然而，元件發(fā)生損壞時的電壓僅幾百伏。</span><span
lang=EN-US style='font-size:9.0pt;font-family:Arial'><br>
</span><span style='font-size:9.0pt;font-family:宋體;mso-ascii-font-family:
Arial;mso-hansi-font-family:Arial;mso-bidi-font-family:Arial'> 靜電放電的危害效應是在二十世紀七十年代開始認識到的，這是由于新技術的發(fā)展導致元件對靜電放電的損壞越來越敏感。靜電放電造成的損失每年可達到幾百萬美元以上。因此，許多大型的元件和設備制造廠引進專業(yè)技術以減小生產環(huán)境中的靜電積累，從而使產品合格率和可靠性提高了許多。用戶根據(jù)自己的經驗也懂得了防治靜電放電損害的重要性。</span><span
lang=EN-US style='font-size:9.0pt;font-family:Arial'><br>
<br>
</span><span style='font-size:9.0pt;font-family:宋體;mso-ascii-font-family:
Arial;mso-hansi-font-family:Arial;mso-bidi-font-family:Arial'>２．如何對付靜電放電？</span><span
lang=EN-US style='font-size:9.0pt;font-family:Arial'><br>
<br>
</span><span style='font-size:9.0pt;font-family:宋體;mso-ascii-font-family:
Arial;mso-hansi-font-family:Arial;mso-bidi-font-family:Arial'> 控制靜電積累的第一步是要弄清楚靜電荷的產生機理。</span><span
lang=EN-US style='font-size:9.0pt;font-family:Arial'><br>
</span><span style='font-size:9.0pt;font-family:宋體;mso-ascii-font-family:
Arial;mso-hansi-font-family:Arial;mso-bidi-font-family:Arial'> 靜電電壓是由不同種類的物質相互接觸與分離而產生。盡管摩擦能夠使電荷積累得更多，但是摩擦并不是必要的。這種效應即是大家熟知的摩擦起電，所產生的電壓取決于相互摩擦的材料本身的特性。磨擦起電序列表列出了各類物質的帶電難易程度。對于相互接觸的兩種物質，電子會從序列表較上的物質轉向較下的物質，這樣就會使兩種物質分別帶正負電荷。序列表中的物質離得越遠，各自所帶的電荷數(shù)量也越大。常見物質的磨擦起電序列如表</span><span
lang=EN-US style='font-size:9.0pt;font-family:Arial'>1</span><span
style='font-size:9.0pt;font-family:宋體;mso-ascii-font-family:Arial;
mso-hansi-font-family:Arial;mso-bidi-font-family:Arial'>所示。</span><span
lang=EN-US style='font-size:9.0pt;font-family:Arial'><br>
<o:p></o:p></span></p>
<div align=center>
<table border=1 cellspacing=0 cellpadding=0 width="56%" style='width:56.0%;
mso-cellspacing:0cm' bordercolordark="#ffffff" bordercolorlight="#000000"
height=210>
<tr style='height:17.25pt'>
<td width="100%" colspan=2 style='width:100.0%;padding:.75pt .75pt .75pt .75pt;
height:17.25pt'>
<p class=MsoNormal align=center style='text-align:center;line-height:
14.0pt'><span lang=EN-US style='font-size:9.0pt;font-family:Arial'> </span><span
style='font-size:9.0pt;font-family:宋體;mso-ascii-font-family:Arial;
mso-hansi-font-family:Arial;mso-bidi-font-family:Arial'>表</span><span
lang=EN-US style='font-size:9.0pt;font-family:Arial'>1 </span><span
style='font-size:9.0pt;font-family:宋體;mso-ascii-font-family:Arial;
mso-hansi-font-family:Arial;mso-bidi-font-family:Arial'>摩擦起電序列</span><span
lang=EN-US style='font-size:9.0pt;font-family:Arial'><o:p></o:p></span></p>
</td>
</tr>
<tr style='height:.75pt'>
<td width="79%" style='width:79.0%;padding:.75pt .75pt .75pt .75pt;
height:.75pt'>
<p class=MsoNormal style='mso-line-height-alt:.75pt'><span
style='font-size:9.0pt;font-family:宋體;mso-ascii-font-family:Arial;
mso-hansi-font-family:Arial;mso-bidi-font-family:Arial'>● 人體</span><span
lang=EN-US style='font-size:9.0pt;font-family:Arial'><o:p></o:p></span></p>
</td>
<td width="21%" rowspan=17 style='width:21.0%;padding:.75pt .75pt .75pt .75pt;
height:.75pt'>
<div align=center>
<table border=1 cellspacing=0 cellpadding=0 width="43%" style='width:
43.0%;mso-cellspacing:0cm;border:outset gray .75pt' height=96>
<tr style='height:70.5pt'>
<td width="100%" style='width:100.0%;border:inset gray .75pt;
background:teal;padding:.75pt .75pt .75pt .75pt;height:70.5pt'>
<p align=center style='text-align:center'><span style='mso-bidi-font-family:
Arial'>＋<span lang=EN-US><br>
<br>
<br>
<br>
<br>
<br>
<br>
<br>
<br>
<br>
<br>
<br>
<br>
<br>
<br>
<br>
<br>
<br>
－<o:p></o:p></span></span></p>
</td>
?? 快捷鍵說明
復制代碼
Ctrl + C
搜索代碼
Ctrl + F
全屏模式
F11
切換主題
Ctrl + Shift + D
顯示快捷鍵
?
增大字號
Ctrl + =
減小字號
Ctrl + -