东莞SIR和CAF表面绝缘电阻测试
1、电化(hua)(hua)(hua)(hua)学迁移(yi)(yi)(ECM)电化(hua)(hua)(hua)(hua)学迁移(yi)(yi)是(shi)在直(zhi)流(liu)电压的(de)影响下(xia)发(fa)生(sheng)的(de)离(li)(li)子(zi)运动。在潮(chao)湿(shi)(shi)条(tiao)(tiao)件(jian)下(xia),金(jin)属离(li)(li)子(zi)会(hui)在阳极(ji)(ji)形成(cheng)(cheng),并(bing)(bing)向(xiang)(xiang)阴极(ji)(ji)迁移(yi)(yi)(见(jian)图6.1),形成(cheng)(cheng)枝晶(jing)(jing)。当枝晶(jing)(jing)连接两(liang)种导(dao)体(ti)时,便造成(cheng)(cheng)了(le)短(duan)路(lu),而(er)(er)且枝晶(jing)(jing)会(hui)因(yin)(yin)(yin)电流(liu)骤增(zeng)而(er)(er)发(fa)生(sheng)熔断(duan)(duan)。2、导(dao)电阳极(ji)(ji)丝(si)(CAF)目前公认(ren)的(de)CAF成(cheng)(cheng)因(yin)(yin)(yin)是(shi)铜离(li)(li)子(zi)的(de)电化(hua)(hua)(hua)(hua)学迁移(yi)(yi)随着铜盐的(de)沉积。在高温高湿(shi)(shi)条(tiao)(tiao)件(jian)下(xia),PCB内部的(de)树(shu)(shu)脂和玻(bo)纤(xian)(xian)之间的(de)附力(li)劣化(hua)(hua)(hua)(hua),促成(cheng)(cheng)玻(bo)纤(xian)(xian)表面的(de)硅烷偶(ou)联剂产(chan)生(sheng)水解,树(shu)(shu)脂和玻(bo)纤(xian)(xian)分离(li)(li)并(bing)(bing)形成(cheng)(cheng)可(ke)供离(li)(li)子(zi)迁移(yi)(yi)的(de)通道。PCB/PCBA绝(jue)缘失(shi)效(xiao)失(shi)效(xiao)机理(li)绝(jue)缘电阻(zu)(zu)是(shi)表征(zheng)PCB绝(jue)缘性(xing)能(neng)的(de)一个简单而(er)(er)且容易测量的(de)指标,绝(jue)缘失(shi)效(xiao)是(shi)指绝(jue)缘电阻(zu)(zu)减小(xiao)。一般(ban),影响绝(jue)缘电阻(zu)(zu)的(de)因(yin)(yin)(yin)素(su)有温度(du)、湿(shi)(shi)度(du)、电场强度(du)以及样品处理(li)等。绝(jue)缘失(shi)效(xiao)通常可(ke)能(neng)发(fa)生(sheng)在PCB表面或(huo)者内部,前者多见(jian)于(yu)电化(hua)(hua)(hua)(hua)学迁移(yi)(yi)(ECM)或(huo)化(hua)(hua)(hua)(hua)学腐蚀,后者则多见(jian)于(yu)导(dao)电阳极(ji)(ji)丝(si)(CAF)。1、电化(hua)(hua)(hua)(hua)学迁移(yi)(yi)(ECM)电化(hua)(hua)(hua)(hua)学迁移(yi)(yi)是(shi)在直(zhi)流(liu)电压的(de)影响下(xia)发(fa)生(sheng)的(de)离(li)(li)子(zi)运动。在潮(chao)湿(shi)(shi)条(tiao)(tiao)件(jian)下(xia),金(jin)属离(li)(li)子(zi)会(hui)在阳极(ji)(ji)形成(cheng)(cheng),并(bing)(bing)向(xiang)(xiang)阴极(ji)(ji)迁移(yi)(yi)(见(jian)图6.1),形成(cheng)(cheng)枝晶(jing)(jing)。当枝晶(jing)(jing)连接两(liang)种导(dao)体(ti)时,便造成(cheng)(cheng)了(le)短(duan)路(lu),而(er)(er)且枝晶(jing)(jing)会(hui)因(yin)(yin)(yin)电流(liu)骤增(zeng)而(er)(er)发(fa)生(sheng)熔断(duan)(duan)。用于(yu)印(yin)制电路(lu)板、阻(zu)(zu)焊油墨、绝(jue)缘漆、胶粘剂,封(feng)装树(shu)(shu)脂微间距、IC封(feng)装材料等绝(jue)缘材料性(xing)能(neng)退化(hua)(hua)(hua)(hua)特性(xing)评估。东莞SIR和CAF表面绝(jue)缘电阻(zu)(zu)测试
电阻测试PCB/PCBA绝(jue)缘(yuan)失(shi)效(xiao)是指(zhi)电(dian)(dian)(dian)(dian)介质在电(dian)(dian)(dian)(dian)压作用(yong)下会产生(sheng)能(neng)量损(sun)(sun)(sun)耗(hao)(hao),这种损(sun)(sun)(sun)耗(hao)(hao)很大时,原先的(de)(de)电(dian)(dian)(dian)(dian)能(neng)转(zhuan)化为(wei)热能(neng),使电(dian)(dian)(dian)(dian)介质温度升高,绝(jue)缘(yuan)老化,甚至使电(dian)(dian)(dian)(dian)介质熔化、烧焦,**终(zhong)丧失(shi)绝(jue)缘(yuan)性能(neng)而(er)发生(sheng)热击(ji)穿(chuan)。电(dian)(dian)(dian)(dian)介质的(de)(de)损(sun)(sun)(sun)耗(hao)(hao)是衡(heng)量其(qi)绝(jue)缘(yuan)性能(neng)的(de)(de)重(zhong)要指(zhi)标,电(dian)(dian)(dian)(dian)介质即绝(jue)缘(yuan)材(cai)料,是电(dian)(dian)(dian)(dian)气设(she)备、装置中用(yong)来(lai)隔离存(cun)在不同(tong)点(dian)位(wei)的(de)(de)导(dao)体的(de)(de)物(wu)质,通过各类导(dao)体间的(de)(de)绝(jue)缘(yuan)隔断功能(neng)控制电(dian)(dian)(dian)(dian)流(liu)的(de)(de)方向。电(dian)(dian)(dian)(dian)介质长期受到点(dian)场(chang)、热能(neng)、机械应力等的(de)(de)破坏(huai)。在电(dian)(dian)(dian)(dian)场(chang)的(de)(de)作用(yong)下,电(dian)(dian)(dian)(dian)介质会发生(sheng)极化、电(dian)(dian)(dian)(dian)导(dao)、耗(hao)(hao)损(sun)(sun)(sun)和击(ji)穿(chuan)等现象,这些现象的(de)(de)相关物(wu)理参数可以(yi)用(yong)相对介电(dian)(dian)(dian)(dian)系数、电(dian)(dian)(dian)(dian)导(dao)率、介质损(sun)(sun)(sun)耗(hao)(hao)因(yin)数、击(ji)穿(chuan)电(dian)(dian)(dian)(dian)压来(lai)表征。陕(shan)西PCB绝(jue)缘(yuan)电(dian)(dian)(dian)(dian)阻测(ce)试(shi)市场(chang)在电(dian)(dian)(dian)(dian)子设(she)备领域,表面阻抗(kang)测(ce)试(shi)SIR测(ce)试(shi)被认为(wei)是评(ping)估用(yong)户线路板组装材(cai)料可靠(kao)性的(de)(de)有效(xiao)评(ping)估手段。
Sir电(dian)(dian)(dian)阻测(ce)(ce)(ce)试(shi)可(ke)以(yi)(yi)应用(yong)(yong)(yong)(yong)于各种(zhong)不(bu)同(tong)的电(dian)(dian)(dian)路(lu)(lu)(lu)(lu)中(zhong)。无论是(shi)简单的电(dian)(dian)(dian)路(lu)(lu)(lu)(lu)还是(shi)复杂的电(dian)(dian)(dian)路(lu)(lu)(lu)(lu),都可(ke)以(yi)(yi)使用(yong)(yong)(yong)(yong)Sir电(dian)(dian)(dian)阻测(ce)(ce)(ce)试(shi)来(lai)(lai)测(ce)(ce)(ce)量电(dian)(dian)(dian)阻值。这种(zhong)测(ce)(ce)(ce)试(shi)方法(fa)不(bu)仅适用(yong)(yong)(yong)(yong)于实验室环境,也适用(yong)(yong)(yong)(yong)于工业(ye)生(sheng)(sheng)产(chan)中(zhong)。在工业(ye)生(sheng)(sheng)产(chan)中(zhong),Sir电(dian)(dian)(dian)阻测(ce)(ce)(ce)试(shi)可(ke)以(yi)(yi)用(yong)(yong)(yong)(yong)来(lai)(lai)检测(ce)(ce)(ce)电(dian)(dian)(dian)路(lu)(lu)(lu)(lu)中(zhong)的故障,提高生(sheng)(sheng)产(chan)效(xiao)率。除(chu)了测(ce)(ce)(ce)量电(dian)(dian)(dian)阻值,Sir电(dian)(dian)(dian)阻测(ce)(ce)(ce)试(shi)还可(ke)以(yi)(yi)用(yong)(yong)(yong)(yong)来(lai)(lai)检测(ce)(ce)(ce)电(dian)(dian)(dian)路(lu)(lu)(lu)(lu)中(zhong)的其他问题。例如,它可(ke)以(yi)(yi)用(yong)(yong)(yong)(yong)来(lai)(lai)检测(ce)(ce)(ce)电(dian)(dian)(dian)路(lu)(lu)(lu)(lu)中(zhong)的短(duan)路(lu)(lu)(lu)(lu)和断(duan)路(lu)(lu)(lu)(lu)。通过测(ce)(ce)(ce)量电(dian)(dian)(dian)磁(ci)场的变化,可(ke)以(yi)(yi)判断(duan)电(dian)(dian)(dian)路(lu)(lu)(lu)(lu)中(zhong)是(shi)否存在短(duan)路(lu)(lu)(lu)(lu)或断(duan)路(lu)(lu)(lu)(lu)问题。这种(zhong)测(ce)(ce)(ce)试(shi)方法(fa)可(ke)以(yi)(yi)帮(bang)助工程师快速定位电(dian)(dian)(dian)路(lu)(lu)(lu)(lu)中(zhong)的问题,并进行修(xiu)复。
绝缘电(dian)(dian)(dian)(dian)阻(zu)测(ce)量(liang)(liang):-偏置(zhi)电(dian)(dian)(dian)(dian)压:100V+2V-测(ce)量(liang)(liang)电(dian)(dian)(dian)(dian)压为(wei)100v时(shi)(shi)(shi)(shi)无极化(hua)变化(hua)-**小(xiao)(xiao)时(shi)(shi)(shi)(shi)间(jian)斜坡到100V=2秒-测(ce)量(liang)(liang)时(shi)(shi)(shi)(shi)间(jian)=60秒-被测(ce)样(yang)品(pin)(pin)应与其他样(yang)品(pin)(pin)电(dian)(dian)(dian)(dian)隔离限流电(dian)(dian)(dian)(dian)阻(zu):**小(xiao)(xiao)1mohm与PCB串联(lian)在线(xian)测(ce)试程序:1)PCB干燥后(hou)立即进(jin)行绝缘电(dian)(dian)(dian)(dian)阻(zu)测(ce)量(liang)(liang);2)将样(yang)品(pin)(pin)放(fang)入(ru)环境测(ce)试箱,并连接到在线(xian)测(ce)量(liang)(liang)设备。在试验(yan)(yan)结(jie)束(shu)前,不能(neng)(neng)取出样(yang)品(pin)(pin),也(ye)不能(neng)(neng)打(da)开(kai)(kai)试验(yan)(yan)箱。(组(zu)数(shu)(shu)据(ju))3)施(shi)加(jia)温(wen)度至85℃(持续时(shi)(shi)(shi)(shi)间(jian)3小(xiao)(xiao)时(shi)(shi)(shi)(shi)),然后(hou)施(shi)加(jia)湿度至85%的(de)相对湿度(持续时(shi)(shi)(shi)(shi)间(jian)另一个3小(xiao)(xiao)时(shi)(shi)(shi)(shi)),没有偏置(zhi)电(dian)(dian)(dian)(dian)压(第二(er)组(zu)数(shu)(shu)据(ju))。在85℃,85%湿度下放(fang)置(zhi)96小(xiao)(xiao)时(shi)(shi)(shi)(shi)后(hou),测(ce)量(liang)(liang)绝缘电(dian)(dian)(dian)(dian)阻(zu)为(wei)IR初始(shi)值(第三组(zu)数(shu)(shu)据(ju))4)开(kai)(kai)始(shi)输出偏置(zhi)电(dian)(dian)(dian)(dian)压100V-标(biao)记为(wei)0小(xiao)(xiao)时(shi)(shi)(shi)(shi),开(kai)(kai)始(shi)试验(yan)(yan);智能(neng)(neng)电(dian)(dian)(dian)(dian)阻(zu)具有更加(jia)便捷的(de)操作和数(shu)(shu)据(ju)处理(li)能(neng)(neng)力。
从(cong)监控(kong)的(de)(de)方式看(kan):都是通过监控(kong)其(qi)绝缘(yuan)阻(zu)值变化作为(wei)**重要(yao)的(de)(de)判断指标;故很多汽车行(xing)业或实验室已习惯上(shang)把ECM/SIR从(cong)广义上(shang)定(ding)义为(wei)CAF的(de)(de)一(yi)种(线(xian)(xian)与(yu)线(xian)(xian)之间的(de)(de)表(biao)面CAF)。ECM/SIR与(yu)CAF的(de)(de)联(lian)系与(yu)差异差异点:从(cong)产(chan)生(sheng)的(de)(de)原因看(kan):ECM/SIR是在(zai)PCB的(de)(de)表(biao)面产(chan)生(sheng)金属离子的(de)(de)迁移;而CAF是发(fa)生(sheng)在(zai)PCB的(de)(de)内部出(chu)现铜(tong)离子沿着玻纤发(fa)生(sheng)缓慢迁移,进而出(chu)现漏电;从(cong)产(chan)生(sheng)的(de)(de)现象看(kan):ECM/SIR会(hui)在(zai)导体间出(chu)现枝丫状(zhuang)(Dendrite)物质;而CAF则是出(chu)现在(zai)孔~孔、线(xian)(xian)~线(xian)(xian)、层(ceng)~层(ceng)、孔~线(xian)(xian)间,出(chu)现阳极金属丝;智能电阻(zu)的(de)(de)应(ying)用范围更加(jia)广,可以满足不同行(xing)业和领域的(de)(de)需求(qiu)。湖南pcb板(ban)电阻(zu)测(ce)试(shi)系统
选择智能电(dian)阻(zu)时,用户需要考(kao)虑测量范(fan)围和(he)(he)分辨率(lv)。东(dong)莞SIR和(he)(he)CAF表面绝缘(yuan)电(dian)阻(zu)测试(shi)
离子(zi)迁移(ECM/SIR/CAF)的要(yao)因(yin)分(fen)析与解(jie)决方(fang)(fang)(fang)(fang)案(an)从设计(ji)(ji)(ji)方(fang)(fang)(fang)(fang)面(mian):越(yue)小(xiao)的距离(孔(kong)(kong)~孔(kong)(kong)、线(xian)~线(xian)、层(ceng)~层(ceng)、孔(kong)(kong)~线(xian)间)越(yue)易(yi)造(zao)成离子(zi)迁移现象;解(jie)决方(fang)(fang)(fang)(fang)案(an):结合制程能力(li)与材(cai)料(liao)能力(li),优化设计(ji)(ji)(ji)方(fang)(fang)(fang)(fang)案(an);(当然重(zhong)点还(hai)是必须符合客户(hu)要(yao)求)玻纤纱(sha)束(shu)与孔(kong)(kong)排(pai)列的方(fang)(fang)(fang)(fang)向(xiang);纱(sha)束(shu)与孔(kong)(kong)的方(fang)(fang)(fang)(fang)向(xiang)一致(zhi)时,会造(zao)成离子(zi)迁移的可(ke)能性(xing)比(bi)较大(da);解(jie)决方(fang)(fang)(fang)(fang)案(an):尽可(ke)能避免(mian)或(huo)减少纱(sha)束(shu)与孔(kong)(kong)排(pai)列一致(zhi)的可(ke)能性(xing),但此项受客户(hu)产品设计(ji)(ji)(ji)的制约(yue);产品的防湿保护设计(ji)(ji)(ji);解(jie)决方(fang)(fang)(fang)(fang)案(an):选(xuan)择比(bi)较好(hao)的防湿设计(ji)(ji)(ji),如涉(she)及海运(yun),建(jian)议(yi)采用PE袋(dai)或(huo)铝箔袋(dai)包装方(fang)(fang)(fang)(fang)式;东莞SIR和CAF表面(mian)绝缘电阻测试
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零部件冷焊机
自(zi)动焊接(jie)机的(de)工作原理:设备焊接(jie)电源形(xing)式的(de)配置与(yu)比较,众所周知(zhi),焊缝(feng)质量的(de)关键因素之一是焊接(jie)电源的(de)配置。目前(qian)围内(nei)外有四种电源配置或(huo)焊接(jie)方法为(wei)了择头选取,我们进行(xing)了对比分(fen)析。(1)MAG气体保护(hu)焊电源(熔 。
旋(xuan)启式(shi)(shi)和(he)升降式(shi)(shi)阀(fa)(fa)瓣金属密封面。阀(fa)(fa)体和(he)阀(fa)(fa)盖连接形式(shi)(shi):Class150~Class900采用栓(shuan)接阀(fa)(fa)盖;Class1500~Class2500采用自压密封式(shi)(shi)阀(fa)(fa)盖。阀(fa)(fa)盖垫片形式(shi)(shi):Class150~Class3 。
企(qi)业(ye)绩(ji)效(xiao)(xiao)(xiao)管理的(de)(de)特(te)点(dian)介绍如下(xia):企(qi)业(ye)绩(ji)效(xiao)(xiao)(xiao)管理的(de)(de)特(te)点(dian)是实现了一个(ge)闭(bi)环(huan)的(de)(de)业(ye)务(wu)系(xi)统,这(zhei)个(ge)闭(bi)环(huan)有两个(ge)重点(dian):一是分析性数据(ju)与操(cao)作性数据(ju)在业(ye)务(wu)流程中的(de)(de)使(shi)用步骤,二(er)是企(qi)业(ye)绩(ji)效(xiao)(xiao)(xiao)管理循环(huan)反映了交易或运营系(xi)统与分析系(xi)统的(de)(de)不(bu)同 。
表(biao)面(mian)(mian)防(fang)(fang)(fang)护蜡是防(fang)(fang)(fang)锈油(you)的一种(zhong),是一种(zhong)用(yong)于大型机械设备、工(gong)(gong)程机械、汽车车辆(liang)等表(biao)面(mian)(mian)防(fang)(fang)(fang)护处理(li)的化(hua)学(xue)化(hua)工(gong)(gong)产品,主要(yao)为(wei)防(fang)(fang)(fang)止金属表(biao)面(mian)(mian)生(sheng)锈而(er)影响产品外观表(biao)面(mian)(mian)质(zhi)量。行(xing)业(ye)还可称为(wei)防(fang)(fang)(fang)锈油(you),表(biao)面(mian)(mian)防(fang)(fang)(fang)护蜡,防(fang)(fang)(fang)腐(fu)防(fang)(fang)(fang)锈蜡。主要(yao)功(gong)能:用(yong) 。
激(ji)光打码(ma)作(zuo)业(ye)指导书:不(bu)(bu)要(yao)(yao)注视或(huo)(huo)接(jie)触(chu)光束无论使用防护眼镜与否)。眼睛和身体其(qi)他部位(wei)不(bu)(bu)要(yao)(yao)接(jie)触(chu)设备输(shu)出(chu)的(de)激(ji)光或(huo)(huo)漫反射(she)激(ji)光,否则会引起(qi)失明或(huo)(huo)灼伤。禁止(zhi)非专业(ye)人员自行拆卸、修理(li)、改造设备。使用心脏起(qi)搏(bo)器的(de)人员不(bu)(bu) 。
网格(ge)布(bu)的(de)(de)质量和(he)价(jia)格(ge)挂(gua)钩(gou):1.较差的(de)(de)玻纤网格(ge)布(bu)市场价(jia)格(ge)通(tong)常在1.00元-1.60元左右,他的(de)(de)玻纤纤维通(tong)常是一(yi)些啤酒瓶类的(de)(de)废(fei)玻璃制成,生产工艺(yi)(yi)为陶土坩埚拉丝(si),属(shu)国家禁止(zhi)的(de)(de)生产工艺(yi)(yi),表面涂层也非耐碱(jian)乳液。从(cong) 。
高压(ya)焊(han)(han)(han)(han)工(gong)(gong)指(zhi)符合承压(ya)焊(han)(han)(han)(han)缝焊(han)(han)(han)(han)接(jie)(jie)要(yao)求的(de)焊(han)(han)(han)(han)工(gong)(gong)。通(tong)常为压(ya)力(li)容器焊(han)(han)(han)(han)工(gong)(gong),压(ya)力(li)管道焊(han)(han)(han)(han)工(gong)(gong),氩电联焊(han)(han)(han)(han)工(gong)(gong),下向焊(han)(han)(han)(han)焊(han)(han)(han)(han)工(gong)(gong)等。高压(ya)焊(han)(han)(han)(han)工(gong)(gong)因为焊(han)(han)(han)(han)接(jie)(jie)要(yao)求高,操作(zuo)难度较(jiao)大,施(shi)工(gong)(gong)焊(han)(han)(han)(han)接(jie)(jie)时的(de)监管比较(jiao)严格,一直(zhi)以来,是焊(han)(han)(han)(han)工(gong)(gong)行业(ye)里面技术要(yao)求高的(de)项 。
驾(jia)照培(pei)(pei)训(xun)对于驾(jia)驶中的风(feng)险(xian)防范具(ju)有(you)重要(yao)意义。首先,正(zheng)规的驾(jia)照培(pei)(pei)训(xun)能够让(rang)学(xue)员(yuan)多方面(mian)掌(zhang)握驾(jia)驶技能,了(le)解(jie)交通规则和(he)道路标志,从而在驾(jia)驶中更加准确判断和(he)应对风(feng)险(xian)。此外,培(pei)(pei)训(xun)过程中还会教授学(xue)员(yuan)如何处理(li)紧急情况,如 。
公(gong)(gong)司对产(chan)品(pin)的(de)承(cheng)诺(nuo)我(wo)们的(de)公(gong)(gong)司一直致力于为客(ke)户提供高质量的(de)装(zhuang)(zhuang)箱机的(de)服(fu)务(wu)。我(wo)们理解(jie),作为一款重要的(de)生产(chan)设备,装(zhuang)(zhuang)箱机的(de)正常(chang)运行对于公(gong)(gong)司的(de)生产(chan)流(liu)程至关重要。因(yin)此(ci),我(wo)们承(cheng)诺(nuo):产(chan)品(pin)质量:我(wo)们坚持以严格的(de)质量控制(zhi)标准 。
在线水(shui)硬度分析(xi)仪可以快(kuai)速、准确、有效的分析(xi)检(jian)测水(shui)中钙镁离(li)子的浓度和(he)多个水(shui)样的钙离(li)子含量(liang),省时省力(li)。可以作为钙离(li)子、水(shui)总硬度、钙硬度检(jian)测分析(xi)的常规手段。一直以来(lai)钙镁离(li)子选择性电极法未被(bei)大量(liang)使(shi)用和(he)重视(shi),其 。
一则(ze)好的(de)广告标语,是广告成(cheng)功(gong)的(de)要(yao)(yao)素。意念隽(juan)永的(de)广告标语,能一语双关,一面带出企(qi)(qi)业(ye)的(de)形(xing)象(xiang)、一面强调产品的(de)优点,企(qi)(qi)业(ye)形(xing)象(xiang)鲜明,深入(ru)民心,都有(you)赖这句(ju)成(cheng)功(gong)标语历久(jiu)常新(xin)和广告魅力。一则(ze)广告要(yao)(yao)设(she)计美观,有(you)意念,收 。