1、电(dian)(dian)(dian)化(hua)(hua)学(xue)迁(qian)(qian)移(yi)(ECM)电(dian)(dian)(dian)化(hua)(hua)学(xue)迁(qian)(qian)移(yi)是(shi)在直(zhi)流电(dian)(dian)(dian)压的(de)影(ying)响下发(fa)生(sheng)的(de)离(li)(li)子(zi)(zi)运(yun)动。在潮湿(shi)(shi)条(tiao)(tiao)件下,金(jin)属离(li)(li)子(zi)(zi)会(hui)在阳(yang)极形成(cheng)(cheng)(cheng)(cheng),并(bing)向阴极迁(qian)(qian)移(yi)(见(jian)图6.1),形成(cheng)(cheng)(cheng)(cheng)枝(zhi)(zhi)晶(jing)(jing)。当枝(zhi)(zhi)晶(jing)(jing)连接两种导(dao)体时,便(bian)(bian)造成(cheng)(cheng)(cheng)(cheng)了短路,而且(qie)枝(zhi)(zhi)晶(jing)(jing)会(hui)因电(dian)(dian)(dian)流骤增而发(fa)生(sheng)熔断。2、导(dao)电(dian)(dian)(dian)阳(yang)极丝(si)(si)(CAF)目前公认的(de)CAF成(cheng)(cheng)(cheng)(cheng)因是(shi)铜离(li)(li)子(zi)(zi)的(de)电(dian)(dian)(dian)化(hua)(hua)学(xue)迁(qian)(qian)移(yi)随着铜盐的(de)沉积。在高温高湿(shi)(shi)条(tiao)(tiao)件下,PCB内部的(de)树脂和玻(bo)纤之间(jian)的(de)附力劣化(hua)(hua),促成(cheng)(cheng)(cheng)(cheng)玻(bo)纤表(biao)(biao)面(mian)的(de)硅烷偶(ou)联剂(ji)产生(sheng)水解,树脂和玻(bo)纤分离(li)(li)并(bing)形成(cheng)(cheng)(cheng)(cheng)可(ke)供离(li)(li)子(zi)(zi)迁(qian)(qian)移(yi)的(de)通道。PCB/PCBA绝(jue)(jue)(jue)缘(yuan)失效(xiao)失效(xiao)机(ji)理绝(jue)(jue)(jue)缘(yuan)电(dian)(dian)(dian)阻是(shi)表(biao)(biao)征(zheng)PCB绝(jue)(jue)(jue)缘(yuan)性(xing)能的(de)一个(ge)简(jian)单(dan)而且(qie)容(rong)易测量的(de)指标(biao)，绝(jue)(jue)(jue)缘(yuan)失效(xiao)是(shi)指绝(jue)(jue)(jue)缘(yuan)电(dian)(dian)(dian)阻减小。一般(ban),影(ying)响绝(jue)(jue)(jue)缘(yuan)电(dian)(dian)(dian)阻的(de)因素有温度、湿(shi)(shi)度、电(dian)(dian)(dian)场强度以及样品处理等。绝(jue)(jue)(jue)缘(yuan)失效(xiao)通常(chang)可(ke)能发(fa)生(sheng)在PCB表(biao)(biao)面(mian)或者(zhe)(zhe)内部,前者(zhe)(zhe)多见(jian)于电(dian)(dian)(dian)化(hua)(hua)学(xue)迁(qian)(qian)移(yi)(ECM)或化(hua)(hua)学(xue)腐蚀(shi),后者(zhe)(zhe)则(ze)多见(jian)于导(dao)电(dian)(dian)(dian)阳(yang)极丝(si)(si)(CAF)。1、电(dian)(dian)(dian)化(hua)(hua)学(xue)迁(qian)(qian)移(yi)(ECM)电(dian)(dian)(dian)化(hua)(hua)学(xue)迁(qian)(qian)移(yi)是(shi)在直(zhi)流电(dian)(dian)(dian)压的(de)影(ying)响下发(fa)生(sheng)的(de)离(li)(li)子(zi)(zi)运(yun)动。在潮湿(shi)(shi)条(tiao)(tiao)件下,金(jin)属离(li)(li)子(zi)(zi)会(hui)在阳(yang)极形成(cheng)(cheng)(cheng)(cheng),并(bing)向阴极迁(qian)(qian)移(yi)(见(jian)图6.1),形成(cheng)(cheng)(cheng)(cheng)枝(zhi)(zhi)晶(jing)(jing)。当枝(zhi)(zhi)晶(jing)(jing)连接两种导(dao)体时,便(bian)(bian)造成(cheng)(cheng)(cheng)(cheng)了短路,而且(qie)枝(zhi)(zhi)晶(jing)(jing)会(hui)因电(dian)(dian)(dian)流骤增而发(fa)生(sheng)熔断。用于印制电(dian)(dian)(dian)路板、阻焊油墨、绝(jue)(jue)(jue)缘(yuan)漆、胶(jiao)粘剂(ji)，封装树脂微(wei)间(jian)距、IC封装材料等绝(jue)(jue)(jue)缘(yuan)材料性(xing)能退(tui)化(hua)(hua)特性(xing)评估。东(dong)莞SIR和CAF表(biao)(biao)面(mian)绝(jue)(jue)(jue)缘(yuan)电(dian)(dian)(dian)阻测试(shi)

PCB/PCBA绝(jue)缘(yuan)失(shi)(shi)效是指电(dian)(dian)(dian)介(jie)(jie)(jie)(jie)质(zhi)(zhi)(zhi)(zhi)在(zai)电(dian)(dian)(dian)压(ya)作(zuo)用下会产生(sheng)能(neng)量损耗(hao)，这(zhei)种损耗(hao)很大时，原(yuan)先的(de)(de)(de)电(dian)(dian)(dian)能(neng)转(zhuan)化(hua)为(wei)热能(neng)，使电(dian)(dian)(dian)介(jie)(jie)(jie)(jie)质(zhi)(zhi)(zhi)(zhi)温度升(sheng)高，绝(jue)缘(yuan)老化(hua)，甚至使电(dian)(dian)(dian)介(jie)(jie)(jie)(jie)质(zhi)(zhi)(zhi)(zhi)熔化(hua)、烧焦，**终(zhong)丧失(shi)(shi)绝(jue)缘(yuan)性能(neng)而发生(sheng)热击(ji)(ji)穿(chuan)(chuan)。电(dian)(dian)(dian)介(jie)(jie)(jie)(jie)质(zhi)(zhi)(zhi)(zhi)的(de)(de)(de)损耗(hao)是衡(heng)量其绝(jue)缘(yuan)性能(neng)的(de)(de)(de)重要指标，电(dian)(dian)(dian)介(jie)(jie)(jie)(jie)质(zhi)(zhi)(zhi)(zhi)即绝(jue)缘(yuan)材料，是电(dian)(dian)(dian)气(qi)设(she)备、装置中用来(lai)隔(ge)离存在(zai)不(bu)同点位的(de)(de)(de)导(dao)体的(de)(de)(de)物(wu)(wu)质(zhi)(zhi)(zhi)(zhi)，通过各类导(dao)体间的(de)(de)(de)绝(jue)缘(yuan)隔(ge)断功能(neng)控制电(dian)(dian)(dian)流的(de)(de)(de)方向(xiang)。电(dian)(dian)(dian)介(jie)(jie)(jie)(jie)质(zhi)(zhi)(zhi)(zhi)长期受到点场(chang)、热能(neng)、机械应力(li)等的(de)(de)(de)破(po)坏。在(zai)电(dian)(dian)(dian)场(chang)的(de)(de)(de)作(zuo)用下，电(dian)(dian)(dian)介(jie)(jie)(jie)(jie)质(zhi)(zhi)(zhi)(zhi)会发生(sheng)极化(hua)、电(dian)(dian)(dian)导(dao)、耗(hao)损和击(ji)(ji)穿(chuan)(chuan)等现象，这(zhei)些现象的(de)(de)(de)相关物(wu)(wu)理(li)参数可(ke)以用相对介(jie)(jie)(jie)(jie)电(dian)(dian)(dian)系数、电(dian)(dian)(dian)导(dao)率、介(jie)(jie)(jie)(jie)质(zhi)(zhi)(zhi)(zhi)损耗(hao)因(yin)数、击(ji)(ji)穿(chuan)(chuan)电(dian)(dian)(dian)压(ya)来(lai)表征。陕西PCB绝(jue)缘(yuan)电(dian)(dian)(dian)阻(zu)测试市场(chang)在(zai)电(dian)(dian)(dian)子设(she)备领域，表面阻(zu)抗测试SIR测试被认为(wei)是评(ping)估用户(hu)线路板组装材料可(ke)靠性的(de)(de)(de)有效评(ping)估手段。

Sir电(dian)(dian)阻测(ce)(ce)(ce)试(shi)可(ke)(ke)以应用(yong)(yong)于(yu)各种(zhong)不(bu)同的(de)(de)(de)电(dian)(dian)路(lu)(lu)中(zhong)。无论是简单的(de)(de)(de)电(dian)(dian)路(lu)(lu)还是复杂的(de)(de)(de)电(dian)(dian)路(lu)(lu)，都可(ke)(ke)以使用(yong)(yong)Sir电(dian)(dian)阻测(ce)(ce)(ce)试(shi)来(lai)测(ce)(ce)(ce)量电(dian)(dian)阻值。这(zhei)种(zhong)测(ce)(ce)(ce)试(shi)方(fang)法(fa)不(bu)仅适用(yong)(yong)于(yu)实验室环境(jing)，也适用(yong)(yong)于(yu)工(gong)业生(sheng)产中(zhong)。在工(gong)业生(sheng)产中(zhong)，Sir电(dian)(dian)阻测(ce)(ce)(ce)试(shi)可(ke)(ke)以用(yong)(yong)来(lai)检(jian)(jian)测(ce)(ce)(ce)电(dian)(dian)路(lu)(lu)中(zhong)的(de)(de)(de)故障(zhang)，提高生(sheng)产效(xiao)率。除了测(ce)(ce)(ce)量电(dian)(dian)阻值，Sir电(dian)(dian)阻测(ce)(ce)(ce)试(shi)还可(ke)(ke)以用(yong)(yong)来(lai)检(jian)(jian)测(ce)(ce)(ce)电(dian)(dian)路(lu)(lu)中(zhong)的(de)(de)(de)其他问(wen)题(ti)(ti)。例(li)如，它可(ke)(ke)以用(yong)(yong)来(lai)检(jian)(jian)测(ce)(ce)(ce)电(dian)(dian)路(lu)(lu)中(zhong)的(de)(de)(de)短路(lu)(lu)和(he)断(duan)(duan)路(lu)(lu)。通过测(ce)(ce)(ce)量电(dian)(dian)磁场的(de)(de)(de)变(bian)化，可(ke)(ke)以判断(duan)(duan)电(dian)(dian)路(lu)(lu)中(zhong)是否存在短路(lu)(lu)或断(duan)(duan)路(lu)(lu)问(wen)题(ti)(ti)。这(zhei)种(zhong)测(ce)(ce)(ce)试(shi)方(fang)法(fa)可(ke)(ke)以帮助工(gong)程(cheng)师快速定位电(dian)(dian)路(lu)(lu)中(zhong)的(de)(de)(de)问(wen)题(ti)(ti)，并进行修(xiu)复。

绝缘(yuan)电(dian)(dian)(dian)(dian)(dian)阻测(ce)量(liang)(liang):-偏置(zhi)电(dian)(dian)(dian)(dian)(dian)压(ya):100V+2V-测(ce)量(liang)(liang)电(dian)(dian)(dian)(dian)(dian)压(ya)为(wei)100v时(shi)无极化变化-**小(xiao)(xiao)时(shi)间斜坡到(dao)100V=2秒-测(ce)量(liang)(liang)时(shi)间=60秒-被测(ce)样品(pin)应与其他样品(pin)电(dian)(dian)(dian)(dian)(dian)隔离限流电(dian)(dian)(dian)(dian)(dian)阻:**小(xiao)(xiao)1mohm与PCB串联在(zai)(zai)线(xian)(xian)测(ce)试程序：1）PCB干燥后立即(ji)进行绝缘(yuan)电(dian)(dian)(dian)(dian)(dian)阻测(ce)量(liang)(liang);2）将样品(pin)放入环境测(ce)试箱(xiang)，并(bing)连(lian)接到(dao)在(zai)(zai)线(xian)(xian)测(ce)量(liang)(liang)设备。在(zai)(zai)试验(yan)(yan)结束前，不能取出(chu)样品(pin)，也不能打开(kai)试验(yan)(yan)箱(xiang)。（组数(shu)据(ju)(ju)）3）施加温度(du)至85℃(持续时(shi)间3小(xiao)(xiao)时(shi))，然后施加湿度(du)至85%的相对湿度(du)(持续时(shi)间另一个3小(xiao)(xiao)时(shi))，没有偏置(zhi)电(dian)(dian)(dian)(dian)(dian)压(ya)（第二(er)组数(shu)据(ju)(ju)）。在(zai)(zai)85℃，85%湿度(du)下放置(zhi)96小(xiao)(xiao)时(shi)后，测(ce)量(liang)(liang)绝缘(yuan)电(dian)(dian)(dian)(dian)(dian)阻为(wei)IR初始(shi)(shi)(shi)值（第三组数(shu)据(ju)(ju)）4）开(kai)始(shi)(shi)(shi)输出(chu)偏置(zhi)电(dian)(dian)(dian)(dian)(dian)压(ya)100V-标记为(wei)0小(xiao)(xiao)时(shi)，开(kai)始(shi)(shi)(shi)试验(yan)(yan);智能电(dian)(dian)(dian)(dian)(dian)阻具有更加便捷的操作(zuo)和数(shu)据(ju)(ju)处理能力。

从(cong)监控(kong)的(de)(de)(de)方式看：都(dou)是(shi)(shi)通过监控(kong)其绝缘阻(zu)(zu)值(zhi)变化作为**重要的(de)(de)(de)判断指标；故很多汽(qi)车(che)行业(ye)或实验室已习(xi)惯上把ECM/SIR从(cong)广义(yi)(yi)上定(ding)义(yi)(yi)为CAF的(de)(de)(de)一(yi)种（线与线之间的(de)(de)(de)表面CAF）。ECM/SIR与CAF的(de)(de)(de)联系(xi)与差异(yi)差异(yi)点：从(cong)产生的(de)(de)(de)原因看：ECM/SIR是(shi)(shi)在(zai)PCB的(de)(de)(de)表面产生金(jin)属(shu)离(li)子(zi)的(de)(de)(de)迁移；而(er)(er)CAF是(shi)(shi)发生在(zai)PCB的(de)(de)(de)内(nei)部出(chu)(chu)现(xian)(xian)铜离(li)子(zi)沿着(zhe)玻纤发生缓慢迁移,进而(er)(er)出(chu)(chu)现(xian)(xian)漏(lou)电；从(cong)产生的(de)(de)(de)现(xian)(xian)象(xiang)看：ECM/SIR会在(zai)导体间出(chu)(chu)现(xian)(xian)枝丫状(Dendrite)物质；而(er)(er)CAF则是(shi)(shi)出(chu)(chu)现(xian)(xian)在(zai)孔~孔、线~线、层~层、孔~线间，出(chu)(chu)现(xian)(xian)阳极金(jin)属(shu)丝(si)；智能电阻(zu)(zu)的(de)(de)(de)应用范围(wei)更加(jia)广，可(ke)以满足不同行业(ye)和领域的(de)(de)(de)需求。湖(hu)南pcb板(ban)电阻(zu)(zu)测试系(xi)统

选择智能电阻时，用户(hu)需(xu)要考(kao)虑测(ce)量范围和(he)分辨(bian)率(lv)。东莞SIR和(he)CAF表(biao)面(mian)绝缘电阻测(ce)试

离子迁(qian)移（ECM/SIR/CAF)的要(yao)因分析与解决(jue)方案(an)从设(she)计方面：越小的距(ju)离（孔~孔、线~线、层~层、孔~线间）越易造(zao)成(cheng)(cheng)离子迁(qian)移现象；解决(jue)方案(an)：结(jie)合制程能力与材料(liao)能力，优化(hua)设(she)计方案(an)；（当(dang)然重点还是必须符合客户要(yao)求）玻纤纱(sha)束(shu)与孔排(pai)列的方向；纱(sha)束(shu)与孔的方向一(yi)致时，会造(zao)成(cheng)(cheng)离子迁(qian)移的可能性比较大；解决(jue)方案(an)：尽(jin)可能避免或减少(shao)纱(sha)束(shu)与孔排(pai)列一(yi)致的可能性，但(dan)此项受客户产品设(she)计的制约(yue)；产品的防(fang)湿保护设(she)计；解决(jue)方案(an)：选择比较好的防(fang)湿设(she)计，如(ru)涉及(ji)海运，建议采用PE袋或铝(lv)箔袋包装方式；东莞SIR和(he)CAF表面绝缘电阻测试

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