欢迎来到天天文库
浏览记录
ID:46284765
大小:78.50 KB
页数:5页
时间:2019-11-22
《PCB专业英语3》由会员上传分享,免费在线阅读,更多相关内容在工程资料-天天文库。
1、i)NCDrilling数控钻孔Panelsarrivingfromthevacuumpresswillbedrilledtocreateinterconnectionsbetweenthedifferentlayersofthecircuitry.ThedrillsarcCNCcontrolledandreceivefilesfromCAMwhichcontainthenumberofhits,holesizes,andthepathforthedril1headtofollow.层压后到钻孔工序进行孔加工,使各层线路间形成网络连接。数控钻机从CAM中接受
2、数据文件,包扌舌钻孔数、孔大小及钻孔路径。•Panelsfromthelaminationpressesarefirstroutedandedgebeveledtocleanuptheedgesofthepanels.Thetoolingholesarespotfacedtoallowthepanelstolieflatonthedri11table.层压后先裁连,以使板连平整。铳出定位孔处的铜箔,用冲孔机冲出定位孔。Panelsaredrilledtypicallyinstacksof3high+entryfoil&backupmaterial.一般是钻3
3、个定位孔。•Largerdri11smayprocess4-5panelstackssimultaneously.大孔可以4-5叠板同吋钻。•Toolmanagementsystemprovidesstorageforupto120drillsperspindle,automatictoolchangewhenmaximumhitsreached.钻刀库可以存放120把刀每个钻轴,在钻孔时可以口动的更换钻刀。•DrillROMandplungespeedareautomaticallyadjustedforeachdri11size.钻速与进给速度根据钻刀大
4、小来调节。•Typicalpanelshave10000-12000holes(someasmuchas30K)•Takesapprox.1hourtoprocess.一般的板要钻10000-12000个孔(最多可达到3万),大约需钻一个小时。•PanelsarecheckedwithX-RaysforholeRegistrationininner-layers.Introductionofscalefactormaybenecessarytocenterdrillpatterntocopperpattern.X-Reiy机可以测量内层上的孔位置精度,通过涨
5、缩系数的调整是必要的,可以使钻孔与导体图形对止。•Smal1estdri11holecapabilityis13.5mi1diameterwithadri11aspectratioof6:1.最小能钻直径直径为13.5mil的孔,最小板厚孔径为6:loDeburringAsdrillremovescopperasmallcopperridgeformsaroundtheholeedge.Theburrismechanicallyremovedusingscrubbingbrushesandhighpressurewaterblasttoremoveanyde
6、brisfromtheholes.去毛刺一钻孔后会在铜箔和孔壁上产生粗糙边。用机械方法(通常是用旋转的、含磨料的尼龙刷辘及高压水流水洗)去除毛刺。ii)ElectrolessCrpper沉铜Desmear:Frictionduringdrillingcausesthedrilltoheat-upandmelttheresinbetweencopperlayers.Asthedrillisremoved・Thesoftresinwillsmearacrossinternalconductors.Thesmearedresinwillpreventelectri
7、calconnectontoinnerlayers,itmustberemovedbychemicalorplasmaattack.Coretecutilizesachemicalpermanganatedesmearprocess.Etchback:Somespecificationsrequireelectricalconnectiontothreesurfacesoninternalconductors,henceinadditiontodesmear,additionalresinandglassfibremustberelievedfromtheh
8、olewalltoallowaccesstothre
此文档下载收益归作者所有