CEOB2B晶振平台

an style=";font-family:宋体;color:#7f7f7f;font-size:12px">an face="宋体">目前，移动电话中包含数片射频an>ICan face="宋体">以及许多无源器件。今后短期内的主要任务将是把所有这些无源晶振器件与简单的半导体器件an>an face="Calibri">(an>an face="宋体">如开关二极管an>an face="Calibri">)an>an face="宋体">集成在一起，缩成几个模块。由于声表滤波器是所有无源器件中最精密的，所以这种集成将由声表滤波器制造商来完成。an>an face="Calibri">EPCOSan>an face="宋体">将以其专有芯片尺寸的声表滤波器封装技术和多层an>an face="Calibri">LTCCan>an face="宋体">技术来应付这种挑战。an>an face="Calibri">Thomas Baieran>an face="宋体">说：“可以相信，将来这种an>an face="Calibri">LTCCan>an face="宋体">声表滤波器模块会把余下的几块射频an>an face="Calibri">ICan>an face="宋体">也集成进去。”声表面滤波器与an>an face="Calibri">ICan>an face="宋体">集成的主要难点是：声表滤波器必须密闭封装，主要原因是声表滤波器模片表面不能被其它东西接触。an>an>

an style="font-size:16px">平面倒边石英片厚度的确定：an>an style="font-size: 16px;">当直径与厚度比45<Φ/t<60范围时，为了消除边缘效应的影响，an>石英晶振an style="font-size: 16px;">片的外形一般采用平面倒边。如图3.4.3所示，但目前实际生产中,当15<Φ/t<<60时,都采用平面倒边。由于其加工方法比平凸、双凸更方便，且能达到产品规格要求，石英片的厚度计算公式可用下列近似式计算。an>

an style="font-size:12px;font-family:微软雅黑, sans-serif">an style="font-size:16px;font-family:"microsoft yahei"">an style="color:#FF0000;">石英晶体an>与空气的摩擦an>an style="font-size:16px;font-family:"microsoft yahei"">(an>an style="font-size:16px;font-family:"microsoft yahei"">表面损耗an>an style="font-size:16px;font-family:"microsoft yahei"">)an>an style="font-size:16px;font-family:"microsoft yahei"">形成的阻力有关。可通过对外盒抽真空以减小损an>an>an style="font-family:"microsoft yahei";font-size:16px;text-indent:18px">耗,an>an style="font-size: 16px; font-family: "microsoft yahei";">与an style="color:#ff0000">温补晶振an>表面微粒间的摩擦有关。可提高石英片表面光洁度an>an style="font-size: 16px; font-family: "microsoft yahei";">,an>an style="font-size: 16px; font-family: "microsoft yahei";">控制腐蚀量an>an style="font-size: 16px; font-family: "microsoft yahei";">,an>an style="font-size: 16px; font-family: "microsoft yahei";">减小砂痕、沙坑、提高银层的牢固度及整体性来减小,an>an style="font-size: 12px; font-family: 微软雅黑, sans-serif;">an style="font-size:16px;font-family:"microsoft yahei"">与an style="color:#ff0000">贴片晶振an>的内摩擦an>an style="font-size:16px;font-family:"microsoft yahei"">,an>an style="font-size:16px;font-family:"microsoft yahei"">自由振动时内部晶格的变化an>an style="font-size:16px;font-family:"microsoft yahei"">,an>an style="font-size:16px;font-family:"microsoft yahei"">产生内应力及加工过程中形成的内应力而引起内部损耗有关。an>an>

an style="font-size:16px;font-family:微软雅黑, sans-serif">晶片直径的确定an>

an style="font-size:12px;font-family:微软雅黑, sans-serif">an style="font-size:16px">首先要考虑所规定的晶体盒能容纳石英片的最大尺寸an>an style="font-size:16px">,an>an style="font-size:16px">再设计满足此条件的石英片直径。石英片的直径大小对石英晶体元件的活力和寄生振动有很大影响。an>an style="font-size:16px">ATan>an style="font-size:16px">切型的寄生振动主要包括an>an style="font-size:16px">xy’an>an style="font-size:16px">弯曲、an>an style="font-size:16px">y’an>an style="font-size:16px">面切变和an>an style="font-size:16px">xy’an>an style="font-size:16px">伸缩等三种振动。an>an>

an style="font-size:12px;font-family:微软雅黑, sans-serif">an style="font-size:16px">如果主振动频率与上述三种振动之一的高次泛音频率接近时an>an style="font-size:16px">,an>an style="font-size:16px">就出现强耦合作用an>an style="font-size:16px">,an>an style="font-size:16px">引起活力突变或频率跳跃等现象。这种现象在an>an style="font-size:16px">ATan>an style="font-size:16px">切型的低频端及边比Φan>an style="font-size:16px">/tan>an style="font-size:16px">小的情况下容易出现。所以当Φan>an style="font-size:16px">/<20an>an style="font-size:16px">时an>an style="font-size:16px">,an>an style="font-size:16px">就应该严格控制直径Φ的尺寸。an>an>

an style=";font-family:宋体;color:#7f7f7f;font-size:12px">an face="宋体">什么是石英晶体谐振器呢？这是一种利用频率和振荡为产品提供实时时钟信号，带动其他电子元件发挥作用的电子元件。晶振有高端也有低端，以前的手机生产厂家为了节省成本，获取更多的利益往往选用一些比较低端的石英贴片晶振甚至是an>32.768Kan face="宋体">的圆柱晶振，导致安卓手机的各方面性能不尽如人意。但现在不同了，经济水平不断的增长，对智能手机的要求越来越高，为了一部好手机舍得花钱，所以那些智能机生产企业为了留住市场，为安卓手机匹配一些比较好的贴片晶振，使国产安卓手机有了一个质的飞跃。an>an>

an style="font-size:12px;font-family:微软雅黑, sans-serif">an style="font-size:16px">在确定石英晶振片切角误差时an>an style="font-size:16px">,an>an style="font-size:16px">还应对照图an>an style="font-size:16px">3.2.5an>an style="font-size:16px">曲线an>an style="font-size:16px">,an>an style="font-size:16px">估计有无加工的可能性。对于an>an style="font-size:16px">ATan>an style="font-size:16px">切由an>an style="font-size:16px">XX’an>an style="font-size:16px">角误差引起的an>an style="font-size:16px">ZZ’an>an style="font-size:16px">角之测试误差见图an>an style="font-size:16px">3.2.6an>an>

an style="font-size:12px;font-family:微软雅黑, sans-serif">an style="font-size:16px">【例】对于an>an style="font-size:16px">HC-49U/s-SMD-8000KHlzan>an style="font-size:16px">规格进行晶振频率温度特性测试an>an style="font-size:16px">,an>an style="font-size:16px">并修正切角。an>an>

an style="font-size:12px;font-family:微软雅黑, sans-serif">an style="font-size:16px">(1)an>an style="font-variant-numeric:normal;font-stretch:normal;font-size:16px;font-family:'times new roman'">   an>an>an style="font-size:12px;font-family:微软雅黑, sans-serif">an style="font-size:16px">其石英片规格为石英片长度an>an style="font-size:16px">Lan>an style="vertical-align:baseline">an style="font-size:16px">xan>an>an style="font-size:16px">=7.995mm,Wan>an style="vertical-align:baseline">an style="font-size:16px">zan>an>an style="font-size:16px">=1.985mm,an>an style="font-size:16px">最后滚倒频率为an>an style="font-size:16px">fan>an style="vertical-align:baseline">an style="font-size:16px">Gan>an>an style="font-size:16px">=7865an>an style="font-size:16px">±an>an style="font-size:16px">15KHz,an>an style="font-size:16px">石英片厚度an>an style="font-size:16px">tan>an style="vertical-align:baseline">an style="font-size:16px">Gan>an>an style="font-size:16px">=0.212mm,an>an style="font-size:16px">平台长轴an>an style="font-size:16px">Lan>an style="vertical-align:baseline">an style="font-size:16px">Xan>an>an style="font-size:16px">=5.77mm,an>an style="font-size:16px">倒边半径an>an style="font-size:16px">R=60mm,an>an style="font-size:16px">留边量an>an style="font-size:16px">t0an>an style="font-size:16px">≤an>an style="font-size:16px">0.08mm,an>an style="font-size:16px">切型切角为an>an style="font-size:16px">AT35an>an>an style="vertical-align:baseline">an style="font-size:16px;font-family:微软雅黑, sans-serif">°an>an>an style="font-size:16px;font-family:微软雅黑, sans-serif">13’an>an style="font-size:12px;font-family:微软雅黑, sans-serif">an style="font-size:16px">±an>an style="font-size:16px">1’an>an style="font-size:16px">。an>an>

an style=";font-family:宋体;color:#7f7f7f;font-size:12px">an face="宋体">贴片石英晶振一直在不断进化中，这不仅体现在an>SMDan face="宋体">晶振的外观上，它的电气性能也越来越好。尺寸封装有日系品牌an>an face="Calibri">NDKan>an face="宋体">晶振中的an>an face="Calibri">MHZan>an face="宋体">晶体单元中，最小的贴片晶振封装an>an face="Calibri">1.2*1.0*0.25mman>an face="宋体">的an>an face="Calibri">1210an>an face="宋体">石英晶体，不仅长度最小厚度也是最薄的。石英晶振的电气性能变化主要体现在需要高要求的有源晶振上，对大多采购商而言有源晶振使用的还是进口晶振品牌多一些。an>an>

an style="font-family: " microsoft="" yahei";="" font-size:="" 16px;"="">an style="color:#FF0000;">石英晶体an>元件的频率温度系数TF与一级、二级、三级系数有关；晶体元件的频率温度系数TF是温度的函数,因此频率温度系数是在某一温度时的频率温度系数;频率温度系数的大小,反应了石英晶体元件的温度稳定性;an>an style="font-family: " microsoft="" yahei";="" font-size:="" 16px;"="">当T=T0时,则TF=a0,这表明只有在a0=0的条件下,才存在零温度系数,所以,a0=0的切型称为零温度系数切型。an>

an style="font-size:12px;font-family:微软雅黑, sans-serif">an style="font-size:16px">一级、二级、三级温度系数an>an style="font-size:16px">aan>an style="vertical-align:baseline">an style="font-size:16px">0an>an>an style="font-size:16px">、an>an style="font-size:16px">ban>an style="vertical-align:baseline">an style="font-size:16px">0an>an>an style="font-size:16px">和an>an style="font-size:16px">can>an style="vertical-align:baseline">an style="font-size:16px">0an>an>an style="font-size:16px">不仅与参考温度有关，而且还与石英晶振切an>an style="font-size:16px">角有关。an>an style="font-size:16px">ATan>an style="font-size:16px">切型的an>an style="font-size:16px">aan>an style="vertical-align:baseline">an style="font-size:16px">0an>an>an style="font-size:16px">、an>an style="font-size:16px">ban>an style="vertical-align:baseline">an style="font-size:16px">0an>an>an style="font-size:16px">、an>an style="font-size:16px">can>an style="vertical-align:baseline">an style="font-size:16px">0an>an>an style="font-size:16px">随角度的变化率为：an>an>

an style="font-size:12px;font-family:微软雅黑, sans-serif">an style="font-size:16px">αan>an style="font-size:16px">aan>an style="vertical-align:baseline">an style="font-size:16px">0an>an>an style="font-size:16px">/an>an style="font-size:16px">αφan>an style="vertical-align:baseline">an style="font-size:16px">1an>an>an style="font-size:16px">=-5.15×10-an>an style="vertical-align:baseline">an style="font-size:16px">6an>an>an style="font-size:16px">/an>an style="vertical-align:baseline">an style="font-size:16px">oan>an>an style="font-size:16px">Can>an style="font-size:16px">度；an>an>

an style="font-size:12px;font-family:微软雅黑, sans-serif">an style="font-size:16px">αan>an style="font-size:16px">ban>an style="vertical-align:baseline">an style="font-size:16px">0an>an>an style="font-size:16px">/an>an style="font-size:16px">αφan>an style="vertical-align:baseline">an style="font-size:16px">1an>an>an style="font-size:16px">=-4.7×10-an>an style="vertical-align:baseline">an style="font-size:16px">9an>an>an style="font-size:16px">/an>an style="vertical-align:baseline">an style="font-size:16px">oan>an>an style="font-size:16px">Can>an style="vertical-align:baseline">an style="font-size:16px">2an>an>an style="font-size:16px">度；an>an>

an style="font-size:12px;font-family:微软雅黑, sans-serif">an style="font-size:16px">αan>an style="font-size:16px">can>an style="vertical-align:baseline">an style="font-size:16px">0an>an>an style="font-size:16px">/an>an style="font-size:16px">αφan>an style="vertical-align:baseline">an style="font-size:16px">1an>an>an style="font-size:16px">=2.0×10-an>an style="vertical-align:baseline">an style="font-size:16px">12an>an>an style="font-size:16px">/an>an style="vertical-align:baseline">an style="font-size:16px">oan>an>an style="font-size:16px">Can>an style="vertical-align:baseline">an style="font-size:16px">3an>an>an style="font-size:16px">度；an>an>