PCB的镀金层或其它镀层中硬度、模量等机械性能检测方案(纳米压痕仪)

AN038enQHischeCoating Thicknessh Material Analysis Application of FISCHER products Determining the mechanical characteristics of gold coatings onconductive traces in printed circuit boards Nowadays， ever thinner coatings are being used inthe electronics industry， not only to save materialbut also because of rapidly shrinking structuresizes. Toreliablydetermine the mechanicalcharacteristics of， for example， gold coatings with athickness of only a few hundred nm， a precise andaccurate measurement technique is required. The thin Au coatings used on PCBs must serve variouspurposes： ascorrosion protection， to improvesolderability and to protect against wear. For detectingthe mechanical characteristics of these thin coatings，such ashardnessorelasticity， the instrumentedindentation test is a well suited method with the furtheradvantage of avoiding any influence of the substrate onthe measurement results. Fig.1： Au-coated printed circuit board For applications subject to mechanical stress， such assliding contacts， the mechanical characteristics mustexhibit absolutely non-varying parameters. Figures 2 and 3 show the measurement results of twodifferent goldcoatings.Usingthe instrumentedindentation test， a 0.5 pm Au coating was loaded with atest load of 0.2 mN and a 0.2 pm Au coating with a testload of just 0.05 mN. TheFISCHER PICODENTOR HM500measuringsystem is designed specifically to handle such small loadparameters and travel distances. To better compare theresults from the two samples， the time of the test loadwas adjusted so that the load increase curves both hadthe same slope. Fig.2： Schematic of a load-displacement curve including standarddeviation of a 0.2 pm (red) and a 0.5 um (blue) Au coating. F1i1g9.3： Martens hardness (HM) including standard deviation of a 0.2 um(red) and a 0.5 pm (blue) Au coating. Both samples show nearly identical hardness profiles(Fig.3). Based on the standard deviation (variationcoefficient of approx. 5%) one can clearly see howprecisely these parameters can be determined， even forsuch thin coatings. Toprecisely andaccurately determine criticalmechanical characteristics such as hardness andelasticity of even very thin gold coatings， FISCHER'sPICODENTOR HM500 is the ideal instrument. Formore information please contact your local FISCHERrepresentative. 当今，在电子电路行业中所用的涂镀层越来越薄，不仅是为了节约材料，也是为了顺应电子电路产品尺寸不断缩小的趋势。然而为了测量这类只有几百微米涂镀层（如镀金层）的机械性能，一种精确的测量技术——仪器化纳米压痕法，将被运用。PCB上的镀金层有很多用处，如防腐，改善焊接性，提高耐磨性，如果想检测它镀金层的各类机械性能如硬度或弹性，菲希尔（Fischer）的HM500这种仪器化纳米压痕测试法是最佳的测量手段，其显著的测量优势可以避免基材本身对测量镀层时的影响。