婷婷色国产精品视频一区,极品丝袜乱系列全集大全目录,日韩国语高清视频在线观看,国产老熟女老女人老人,日本乱人伦av线,香港**毛片在线播放

博(Bo)运(Yun)发(Fa)---欢(Huan)迎(Ying)客(Ke)户(Hu)朋(Peng)友(You)来(Lai)我(Wo)司(Si)工(Gong)厂(Chang)考(Kao)察(Cha)指(Zhi)导(Dao)!(?)

24H热(Re)线(Xian):(?)189 2743 2288

QQ: 3007963705

工(Gong)业(Ye)级(Ji)电(Dian)路(Lu)板(Ban)核(He)心(Xin)厂(Chang)家(Jia)

一(Yi)站(Zhan)式(Shi)PCBA制(Zhi)造(Zao)服(Fu)务(Wu)专(Zhuan)家(Jia)

当(Dang)BGA间(Jian)距(Ju)太(Tai)小(Xiao)时(Shi),(?)怎(Zen)么(Me)走(Zou)过(Guo)孔(Kong)?(?)—(?)—(?)盘(Pan)中(Zhong)孔(Kong),(?)树(Shu)脂(Zhi)塞(Sai)孔(Kong)来(Lai)解(Jie)决(Jue)!(?)

发(Fa)布(Bu)时(Shi)间(Jian):(?)2019-03-08

0


再(Zai)探(Tan)讨(Tao)HDI板(Ban)之(Zhi)前(Qian),(?)需(Xu)要(Yao)讲(Jiang)一(Yi)个(Ge)知(Zhi)识(Shi)点(Dian):(?)盘(Pan)中(Zhong)孔(Kong)。(?)顾(Gu)名(Ming)思(Si)义(Yi),(?)盘(Pan)中(Zhong)孔(Kong)就(Jiu)是(Shi)在(Zai)焊(Han)盘(Pan)中(Zhong)打(Da)孔(Kong)。(?)这(Zhe)里(Li)的(De)焊(Han)盘(Pan)通(Tong)常(Chang)指(Zhi)的(De)是(Shi)BGA焊(Han)盘(Pan)。(?)

那(Na)么(Me)什(Shi)么(Me)情(Qing)况(Kuang)下(Xia),(?)需(Xu)要(Yao)设(She)计(Ji)为(Wei)盘(Pan)中(Zhong)孔(Kong)呢(Ne)?(?)第(Di)一(Yi)种(Zhong)情(Qing)况(Kuang):(?)BGA间(Jian)距(Ju)太(Tai)小(Xiao),(?)无(Wu)法(Fa)在(Zai)B(?)G(?)A(?)间(Jian)做(Zuo)过(Guo)孔(Kong)时(Shi)。(?)

那(Na)么(Me),(?)当(Dang)BGA间(Jian)距(Ju)小(Xiao)于(Yu)多(Duo)少(Shao)时(Shi)必(Bi)须(Xu)设(She)计(Ji)为(Wei)盘(Pan)中(Zhong)孔(Kong)呢(Ne)?(?)请(Qing)看(Kan)下(Xia)图(Tu)分(Fen)析(Xi):(?)((?)技(Ji)术(Shu)来(Lai)源(Yuan):(?)博(Bo)运(Yun)发(Fa)PCB)(?)


如(Ru)图(Tu)所(Suo)示(Shi):(?) A, B是(Shi)BGA焊(Han)盘(Pan)的(De)中(Zhong)心(Xin),(?)C是(Shi)过(Guo)孔(Kong)的(De)中(Zhong)心(Xin)。(?)((?)题(Ti)主(Zhu)绘(Hui)图(Tu)水(Shui)平(Ping)太(Tai)差(Cha),(?)凑(?)合(He)参(Can)照(Zhao))(?)

  1.  A,B焊(Han)盘(Pan)的(De)最(Zui)小(Xiao)直(Zhi)径(Jing)是(Shi)0.25mm,(?)即(Ji):(?)AE=0.125mm

  2.  C处(Chu)过(Guo)孔(Kong)的(De)最(Zui)小(Xiao)直(Zhi)径(Jing)是(Shi)0.2mm,(?) 即(Ji):(?)CF=0.1mm ((?)机(Ji)械(Xie)孔(Kong)极(Ji)限(Xian)可(Ke)做(Zuo)0.15mm,(?)不(Bu)易(Yi)批(Pi)量(Liang)制(Zhi)作(Zuo),(?)此(Ci)处(Chu)不(Bu)做(Zuo)讨(Tao)论(Lun))(?)

  3. 过(Guo)孔(Kong)到(Dao)焊(Han)盘(Pan)的(De)最(Zui)小(Xiao)距(Ju)离(Li)是(Shi)0.2mm,(?)即(Ji):(?)EF=0.2mm ((?)过(Guo)孔(Kong)到(Dao)焊(Han)盘(Pan)极(Ji)限(Xian)可(Ke)做(Zuo)到(Dao)0.15mm,(?)不(Bu)易(Yi)批(Pi)量(Liang)制(Zhi)作(Zuo),(?)故(Gu)不(Bu)作(Zuo)讨(Tao)论(Lun))(?)

所(Suo)以(Yi),(?)AC=0.125+0.1+0.2=0.425mm

通(Tong)过(Guo)勾(Gou)股(Gu)定(Ding)理(Li)AO2+CO2=AC2可(Ke)以(Yi)得(De)出(Chu):(?)AO=0.3mm ,(?)AB=2AO=0.6mm((?)题(Ti)主(Zhu)在(Zai)卖(Mai)弄(Nong)初(Chu)中(Zhong)数(Shu)学(Xue)…(?)…(?))(?)

故(Gu):(?)当(Dang)BGA球(Qiu)心(Xin)距(Ju)小(Xiao)于(Yu)0.6mm时(Shi),(?)必(Bi)须(Xu)设(She)计(Ji)盘(Pan)中(Zhong)孔(Kong)工(Gong)艺(Yi)!(?)  ((?)技(Ji)术(Shu)来(Lai)源(Yuan):(?)博(Bo)运(Yun)发(Fa)PCB)(?)