白小姐四肖必选一肖

芯片IC单片机解密百科

十年专注单片机解密

浅谈射频电路半PCB设计的流程与注意事项

PCB设计流程

白小姐四肖必选一肖YOUYUProtel99SERUANJIANDESHIYONGYUProtel98DENGRUANJIANBUTONG,YINCI,SHOUXIANJIANYAOTAOLUNCAIYONGProtel99SERUANJIANJINXINGPCBSHEJIDELIUCHENG。

①YOUYUProtel99SECAIYONGDESHIGONGCHENG(PROJECT)SHUJUKUMOSHIGUANLI,ZAIWindows99XIASHIYINHANDE,SUOYIYINGXIANJIANLI1GESHUJUKUWENJIANYONGYUGUANLISUOSHEJIDEDIANLUYUANLITUYUPCBBANTU。

②YUANLITUDESHEJI。WEILEKEYISHIXIANWANGLUOLIANJIE,ZAIJINXINGYUANLISHEJIZHIJIAN,SUOYONGDAODEYUANQIJIANDOUBIXUZAIYUANQIJIANKUZHONGCUNZAI,FOUZE,YINGZAISCHLIBZHONGZUOCHUSUOXUDEYUANQIJIANBINGCUNRUKUWENJIANZHONG。RANHOU,ZHIXUCONGYUANQIJIANKUZHONGDIAOYONGSUOXUDEYUANQIJIAN,BINGGENJUSUOSHEJIDEDIANLUTUJINXINGLIANJIEJIKE。

白小姐四肖必选一肖③YUANLITUSHEJIWANCHENGHOU,KEXINGCHENGYIGEWANGLUOBIAOYIBEIJINXINGPCBSHEJISHISHIYONG。

④PCBDESHEJI。

a.PCBWAIXINGJICHICUNDEQUEDING。GENJUSUOSHEJIDEPCBZAICHANPINDEWEIZHI、KONGJIANDEDAXIAO、XINGZHUANGYIJIYUQITABUJIANDEPEIHELAIQUEDINGPCBDEWAIXINGYUCHICUN。ZAIMECHANICALLAYERCENGYONGPLACETRACKMINGLINGHUACHUPCBDEWAIXING。

b.GENJUSMTDEYAOQIU,ZAIPCBSHANGZHIZUODINGWEIKONG、SHIYAN、CANKAODIANDENG。

c.YUANQIJIANDEZHIZUO。JIARUXUYAOSHIYONGYIXIEYUANQIJIANKUZHONGBUCUNZAIDETESHUYUANQIJIAN,ZEZAIBUJUZHIQIANXUXIANJINXINGYUANQIJIANDEZHIZUO。ZAIProtel99SEZHONGZHIZUOYUANQIJIANDEGUOCHENGBIJIAOJIANDAN,XUANZE“DESIGN”CAIDANZHONGDE“MAKELIBRARY”MINGLINGHOUJIUJINRULEYUANQIJIANZHIZUOCHUANGKOU,ZAIXUANZE“TOOL”CAIDANZHONGDE“NEWCOMPONENT”MINGLINGJIUKEYIJINXINGYUANQIJIANDESHEJI。ZHEISHIZHIXUGENJUSHIJIYUANQIJIANDEXINGZHUANG、DAXIAODENGZAITOPLAYERCENGYIPLACEPADDENGMINGLINGZAIYIDINGDEWEIZHIHUACHUXIANGYINGDEHANPANBINGBIANJICHENGSUOXUDEHANPAN(BAOKUOHANPANXINGZHUANG、DAXIAO、NEIJINGCHICUNJIJIAODUDENG,LINGWAIHAIYINGBIAOCHUHANPANXIANGYINGDEYINJIAOMING),RANHOUYIPLACETRACKMINGLINGZAITOPOVERLAYERCENGZHONGHUACHUYUANQIJIANDEZUIDAWAIXING,QUYIGEYUANQIJIANMINGCUNRUYUANQIJIANKUZHONGJIKE。

白小姐四肖必选一肖d.YUANQIJIANZHIZUOWANCHENGHOU,JINXINGBUJUJIBUXIAN,ZHEILIANGBUFENZAIXIAMIANJUTIJINXINGTAOLUN。

e.YISHANGGUOCHENGWANCHENGHOUBIXUJINXINGJIANCHA。ZHEIYIFANGMIANBAOKUODIANLUYUANLIDEJIANCHA,LINGYIFANGMIANHAIBIXUJIANCHAXIANGHUJIANDEPIPEIJIZHUANGPEIWENTI。DIANLUYUANLIDEJIANCHAKEYIRENGONGJIANCHA,YEKEYICAIYONGWANGLUOZIDONGJIANCHA(YUANLITUXINGCHENGDEWANGLUOYUPCBXINGCHENGDEWANGLUOJINXINGBIJIAOJIKE)。

f.检查无误后,对文件进行存档、输出。在Protel99SE中必须使用“FILE”选项中的“EXPORT”命令,把文件存放到指定的路径与文件中(“IMPORT”命令则是把某一文件调入到Protel99SE中)。注:在Protel99SE中“FILE”选项中的“SAVECOPYAS…”命令执行后,所选取的文件名在Windows98中是不可见的,所以在资源管理器中是看不到该文件的。这与Protel98中的“SAVEAS…”功能不完全一样。

       元器件的布局

由于SMT一般采用红外炉热流焊来实现元器件的焊接,因而元器件的布局影响到焊点的质量,进而影响到产品的成品率。而对于射频电路PCB设计而言,电磁兼容性要求每个电路模块尽量不产生电磁辐射,并且具有一定的抗电磁干扰能力,因此,元器件的布局还直接影响到电路本身的干扰及抗干扰能力,这也直接关系到所设计电路的性能。

YINCI,ZAIJINXINGSHEPINDIANLUPCBSHEJISHICHULEYAOKAOLVPUTONGPCBSHEJISHIDEBUJUWAI,ZHUYAOHAIXUKAOLVRUHEJIANXIAOSHEPINDIANLUZHONGGEBUFENZHIJIANXIANGHUGANRAO、RUHEJIANXIAODIANLUBENSHENDUIQITADIANLUDEGANRAOYIJIDIANLUBENSHENDEKANGGANRAONENGLI。GENJUJINGYAN,DUIYUSHEPINDIANLUXIAOGUODEHAOHUAIBUJINQUJUEYUSHEPINDIANLUBANBENSHENDEXINGNENGZHIBIAO,HENDABUFENHAIQUJUEYUYUCPUCHULIBANJIANDEXIANGHUYINGXIANG,YINCI,ZAIJINXINGPCBSHEJISHI,HELIBUJUXIANDEYOUWEIZHONGYAO。

布局总原则:元器件应尽可能同一方向排列,通过选择PCB进入熔锡系统的方向来减少甚至避免焊接不良的现象;根据经验元器件间最少要有0.5mm的间距才能满足元器件的熔锡要求,若PCB板的空间允许,元器件的间距应尽可能宽。对于双面板一般应设计一面为SMD及SMC元件,另一面则为分立元件。

PCB布线注意事项

SUIZHETONGXINJISHUDEFAZHAN,SHOUCHIWUXIANSHEPINDIANLUJISHUYUNYONGYUELAIYUEGUANG,RU:WUXIANXUNHUJI、SHOUJI、WUXIANPDADENG,QIZHONGDESHEPINDIANLUDEXINGNENGZHIBIAOZHIJIEYINGXIANGZHENGGECHANPINDEZHILIANG。ZHEIXIEZHANGSHANGCHANPINDEYIGEZUIDATEDIANJIUSHIXIAOXINGHUA,ERXIAOXINGHUAYIWEIZHEYUANQIJIANDEMIDUHENDA,ZHEISHIDEYUANQIJIAN(BAOKUOSMD、SMC、LUOPIANDENG)DEXIANGHUGANRAOSHIFENTUCHU。

电磁干扰信号如果处理不当,可能造成整个电路系统的无法正常工作,因此,如何防止和抑制电磁干扰,提高电磁兼容性,就成为设计射频电路PCB时的一个非常重要的课题。同一电路,不同的PCB设计结构,其性能指标会相差很大。本讨论采用Protel99SE软件进行掌上产品的射频电路PCB设计时,如果最大限度地实现电路的性能指标,以达到电磁兼容要求。
        板材的选择

白小姐四肖必选一肖YINSHUADIANLUBANDEJICAIBAOKUOYOUJILEIYUWUJILEILIANGDALEI。JICAIZHONGZUIZHONGYAODEXINGNENGSHIJIEDIANCHANGSHUεr、HAOSANYINZI(HUOCHENGJIEZHISUNHAO)tanδ、REPENGZHANGXISHUCETHEXISHILV。QIZHONGεrYINGXIANGDIANLUZUKANGJIXINHAOCHUANSHUSULV。DUIYUGAOPINDIANLU,JIEDIANCHANGSHUGONGCHASHISHOUYAOKAOLVDEGENGGUANJIANYINSU,YINGXUANZEJIEDIANCHANGSHUGONGCHAXIAODEJICAI。