woman affair redirect married and want to cheat
all wives cheat married men who have affairs go
dating for married men women who cheat on husbands what is infidelity
dating for married men click here what is infidelity
all wives cheat why women cheat on men they love go
open cheat on my wife women who cheat on men
open cheat on my wife women who cheat on men
go uses of viagra in women online
go read here online
go generic viagra vs prescription viagra online
cheaters online love affairs with married men
click here why women cheat on men they love catch a cheater
website website 2nd trimester abortion
website website 2nd trimester abortion
website medication abortion pill 2nd trimester abortion
website misoprostol dose abortion 2nd trimester abortion
online dating a married woman click here
women who cheat on husband catch a cheat how many men have affairs
walgreens photo online coupon queerschool.com walgreens online photo
coupons for prescription medications softballspa.com viagra online coupon
prescription drug coupons click coupons for drugs
cialis coupon lilly ningchao.net cialis coupons and discounts
bystolic coupon 2013 daliresp patient assistance
bimatoprost eyebrows bimatoprost eyebrows bimatoprost sr
"/> 电子元器件布局基本规则-新闻中心-广州市羽凌电子有限公司 亚博足球,亚博足球,亚博88下载亚博88
电子元器件布局基本规则
元器件布局对电路性能有一点的影响,羽凌教你如何布局电子元器件的基本规则?

1. 按电路模块进行布局,实现同一功能的相关电路称为一个模块,电路模块中的元件应采用就近集中原则,同时数字电路和模拟电路分开?

2.定位孔、标准孔等非安装孔周围1.27mm 内不得贴装元、器件,螺钉等安装孔周围3.5mm(对于M2.5)、4mm(对于M3)内不得贴装元器件。?

3. 卧装电阻、电感(插件)、电解电容等元件的下方避免布过孔,以免波峰焊后过孔与元件壳体短路。?

4. 元器件的外侧距板边的距离为5mm。?

5. 贴装元件焊盘的外侧与相邻插装元件的外侧距离大于2mm。?

6. 金属壳体元器件和金属件(屏蔽盒等)不能与其它元器件相碰,不能紧贴印制线、焊盘,其间距应大于2mm。定位孔、紧固件安装孔、椭圆孔及板中其它方孔外侧距板边的尺寸大于3mm。?

7. 发热元件不能紧邻导线和热敏元件;高热器件要均衡分布?

8. 电源插座要尽量布置在印制板的四周,电源插座与其相连的汇流条接线端应布置在同侧。特别应注意不要把电源插座及其它焊接连接器布置在连接器之间,以利于这些插座、连接器的焊接及电源线缆设计和扎线。电源插座及焊接连接器的布置间距应考虑方便电源插头的插拔。?

9. 其它元器件的布置 所有IC 元件单边对齐,有极性元件极性标示明确,同一印制板上极性标示不得多于两个方向 出现两个方向时,两个方向互相垂直。?

10、板面布线应疏密得当,当疏密差别太大时应以网状铜箔填充,网格大于8mil(或0.2mm)。?

?11、贴片焊盘上不能有通孔,以免焊膏流失造成元件虚焊。重要信号线不准从插座脚间穿过。?

?12、贴片单边对齐,字符方向一致,封装方向一致。?

?13、有极性的器件在以同一板上的极性标示方向尽量保持一致?

? ? ? ?元件布线规则

1.画定布线区域距PCB板边≤1mm的区域内,以及安装孔周围1mm内,禁止布线?

2.电源线尽可能的宽,不应低于18mil;信号线宽不应低于12mil; cpu入出线不应低于10mil(或8mil);线间距不低于10mil?

3、 正常过孔不低于30mil?

4、 双列直插:焊盘60mil,孔径40mil 1/4W电阻: 51*55mil(0805表贴);直插时焊盘62mil,孔径42mil 无极电容: 51*55mil(0805表贴);直插时焊盘50mil,孔径28mil?

5、 注意电源线与地线应尽可能呈放射状,以及信号线不能出现回环走线

首页 |亚博足球|亚博足球 |亚博88下载亚博88 | 在线询价 | 联系我们 | 友情链接
? 2005-2013 广州市羽凌电子有限公司 版权所有。 粤ICP备09036035号