an style="font-family:微软雅黑, sans-serif;font-size:16px">石英晶体的疵病an>
an style="font-family:微软雅黑, sans-serif;font-size:16px"> 石英晶体无论是天然的还是人造的an>an style="font-size:16px">,an>an style="font-family:微软雅黑, sans-serif;font-size:16px">都不同程度地存在一些疵病an>an style="font-size:16px">(an>an style="font-family:微软雅黑, sans-serif;font-size:16px">缺陷an>an style="font-size:16px">)an>an style="font-family:微软雅黑, sans-serif;font-size:16px">。它们不仅是由于在<a href="/Quartzcrystal.html" title="石英晶振" target="_blank">石英晶振a>晶体生长过程中受到种种条件的影响而产生an>an style="font-size:16px">,an>an style="font-family:微软雅黑, sans-serif;font-size:16px">就是在已形成的晶体中和生长完成后an>an style="font-size:16px">,an>an style="font-family:微软雅黑, sans-serif;font-size:16px">外界条件的变化an>an style="font-size:16px">(an>an style="font-family:微软雅黑, sans-serif;font-size:16px">主要是温度an>an style="font-size:16px">)an>an style="font-family:微软雅黑, sans-serif;font-size:16px">产生的缺陷。这些缺陷会影响其可用程度和石英晶体元件的性能an>an style="font-size:16px">,an>an style="font-family:微软雅黑, sans-serif;font-size:16px">以下简要介绍几种常见的缺陷。an>
an style="font-family:微软雅黑, sans-serif;font-size:16px">一、双晶an>
an style="font-family:微软雅黑, sans-serif;font-size:16px"> 双晶是指两个以上的同种晶体an>an style="font-size:16px">,an>an style="font-family:微软雅黑, sans-serif;font-size:16px">按一定规律相互连生在一起。即在同块<a href="/SMDcrystal.html" title="贴片晶振" target="_blank">贴片晶振a>晶体中an>an style="font-size:16px">,an>an style="font-family:微软雅黑, sans-serif;font-size:16px">同时存在两个方位不同的左旋部分an>an style="font-size:16px">(an>an style="font-family:微软雅黑, sans-serif;font-size:16px">或右旋部分an>an style="font-size:16px">)an>an style="font-family:微软雅黑, sans-serif;font-size:16px">。其中一部分绕an>an style="font-size:16px">Zan>an style="font-family:微软雅黑, sans-serif;font-size:16px">轴转an>an style="font-size:16px">180an>an style="font-family:微软雅黑, sans-serif;font-size:16px">°后方与另一部分连生在一起an>an style="font-size:16px">,an>an style="font-family:微软雅黑, sans-serif;font-size:16px">这两部分的an>an style="font-size:16px">zan>an style="font-family:微软雅黑, sans-serif;font-size:16px">轴彼此平行an>an style="font-size:16px">,an>an style="font-family:微软雅黑, sans-serif;font-size:16px">所以两部分的光学性能相同an>an style="font-size:16px">,an>an style="font-family:微软雅黑, sans-serif;font-size:16px">而电轴两部分相差an>an style="font-size:16px">180an>an style="font-family:微软雅黑, sans-serif;font-size:16px">°an>an style="font-size:16px">,an>an style="font-family:微软雅黑, sans-serif;font-size:16px">故它们的极性相反an>an style="font-size:16px">(an>an style="font-family:微软雅黑, sans-serif;font-size:16px">见图an>an style="font-size:16px">1.4.1)an>an style="font-family:微软雅黑, sans-serif;font-size:16px">。an>
an style="font-family:微软雅黑, sans-serif;font-size:16px"> 光双晶是异旋晶体的连生an>an style="font-size:16px">,an>an style="font-family:微软雅黑, sans-serif;font-size:16px">即在一块晶体中an>an style="font-size:16px">,an>an style="font-family:微软雅黑, sans-serif;font-size:16px">同时存在左旋和右旋两个部分an>an style="font-size:16px">,an>an style="font-family:微软雅黑, sans-serif;font-size:16px">它们连生在一起an>an style="font-size:16px">,an>an style="font-family:微软雅黑, sans-serif;font-size:16px">左旋和右旋的光轴彼此平行an>an style="font-size:16px">,an>an style="font-family:微软雅黑, sans-serif;font-size:16px">但旋光性相反an>an style="font-size:16px">,an>an style="font-family:微软雅黑, sans-serif;font-size:16px">此外电轴极性也相反an>an style="font-size:16px">(an>an style="font-family:微软雅黑, sans-serif;font-size:16px">见图an>an style="font-size:16px">1.4.2)an>an style="font-family:微软雅黑, sans-serif;font-size:16px">。an>
<a href="/32768Kcrystals.html" target="_blank">alt="1.4.1电双晶极性示意图" />a>an style="font-size:16px">an>
an style="font-size:16px"> an>an style="font-size:16px">(a)an>an style="font-family:微软雅黑, sans-serif;font-size:16px">左旋石英晶体的极性an>an style="font-size:16px">;(b)an>an style="font-family:微软雅黑, sans-serif;font-size:16px">绕光轴转an>an style="font-size:16px">180an>an style="font-family:微软雅黑, sans-serif;font-size:16px">°°后左旋石英晶体的极性an>an style="font-size:16px">C)an>an style="font-family:微软雅黑, sans-serif;font-size:16px">电双晶的极性an>an style="font-size:16px">;an>
an style="font-family:微软雅黑, sans-serif;font-size:16px">图an>an style="font-size:16px">1.4.1an>an style="font-family:微软雅黑, sans-serif;font-size:16px">电双晶极性示意图an>
alt="1.4.2光双晶极性示意图" />an style="font-size:16px">an>
an style="font-size:16px">(a)an>an style="font-family:微软雅黑, sans-serif;font-size:16px">左旋石英晶体的极性an>an style="font-size:16px">;(b)an>an style="font-family:微软雅黑, sans-serif;font-size:16px">右旋石英晶体的极性an>an style="font-size:16px">;(c)an>an style="font-family:微软雅黑, sans-serif;font-size:16px">光双晶的极性an>an style="font-size:16px">;an>
an style="font-family:微软雅黑, sans-serif;font-size:16px">图an>an style="font-size:16px">1.4.2an>an style="font-family:微软雅黑, sans-serif;font-size:16px">光双晶极性示意图an>
an style="font-family:微软雅黑, sans-serif;font-size:16px"> 电双晶又称道芬双晶an>an style="font-size:16px">;an>an style="font-family:微软雅黑, sans-serif;font-size:16px">光双晶又称巴西双晶。双晶的边界可用氢氟酸腐蚀显示出来an>an style="font-size:16px">(an>an style="font-family:微软雅黑, sans-serif;font-size:16px">见图an>an style="font-size:16px">1.4.3)an>an style="font-family:微软雅黑, sans-serif;font-size:16px">。an>
an style="font-family:微软雅黑, sans-serif;font-size:16px"> 双晶多出现在天然<a href="/OSCillator.html" title="石英晶体振荡器" target="_blank">石英晶体振荡器a>,石英晶体中an>an style="font-size:16px">,an>an style="font-family:微软雅黑, sans-serif;font-size:16px">但在石英晶片加工中也会诱发出双晶。例如:石英晶片加热温度超过an>an style="font-size:16px">573an>an style="font-family:微软雅黑, sans-serif;font-size:16px">℃an>an style="font-size:16px">,an>an style="font-family:微软雅黑, sans-serif;font-size:16px">或虽然不超过an>an style="font-size:16px">573an>an style="font-family:微软雅黑, sans-serif;font-size:16px">°an>an style="font-size:16px">C,an>an style="font-family:微软雅黑, sans-serif;font-size:16px">但石英片内部温度梯度太大an>an style="font-size:16px">,an>an style="font-family:微软雅黑, sans-serif;font-size:16px">都可能产生电双晶an>an style="font-size:16px">;an>an style="font-family:微软雅黑, sans-serif;font-size:16px">又如an>an style="font-size:16px">:an>an style="font-family:微软雅黑, sans-serif;font-size:16px">晶片研磨时an>an style="font-size:16px">,an>an style="font-family:微软雅黑, sans-serif;font-size:16px">由于机械应力的作用an>an style="font-size:16px">,an>an style="font-family:微软雅黑, sans-serif;font-size:16px">可能产生微小的道芬双晶。an>
<a href="/TaiwanCrystals.html" target="_blank">alt="1.4.3电双晶,光双晶在Z平面上的腐蚀图像" />a>an style="font-size:16px">an>
an style="font-size:16px">(a)an>an style="font-family:微软雅黑, sans-serif;font-size:16px">电双晶腐蚀图像an>an style="font-size:16px">(b)an>an style="font-family:微软雅黑, sans-serif;font-size:16px">光双晶腐蚀图像an>
an style="font-family:微软雅黑, sans-serif;font-size:16px">图an>an style="font-size:16px">1.4.3an>an style="font-family:微软雅黑, sans-serif;font-size:16px">电双晶、光双晶在an>an style="font-size:16px">zan>an style="font-family:微软雅黑, sans-serif;font-size:16px">平面上的腐蚀图像an>
an style="font-family:微软雅黑, sans-serif;font-size:16px"> 在压电石英晶体元件中an>an style="font-size:16px">,an>an style="font-family:微软雅黑, sans-serif;font-size:16px">一般不允许含有双晶an>an style="font-size:16px">,an>an style="font-family:微软雅黑, sans-serif;font-size:16px">若要利用含有双晶的石英晶片时an>an style="font-size:16px">,an>an style="font-family:微软雅黑, sans-serif;font-size:16px">则对双晶的位置和比例要严加限制an>an style="font-size:16px">,an>an style="font-family:微软雅黑, sans-serif;font-size:16px">因此在石英晶片加工中an>an style="font-size:16px">,an>an style="font-family:微软雅黑, sans-serif;font-size:16px">要力求避免双晶的出现an>
an style="font-family:微软雅黑, sans-serif;font-size:16px"> 二、包裹体an>
an style="font-family:微软雅黑, sans-serif;font-size:16px"> 石英晶体中往往含有固体、胶体和气—一液体三种包裹体。an>
an style="font-family:微软雅黑, sans-serif;font-size:16px"> 固体包裹体是混杂在晶体内部的其它矿物质an>an style="font-size:16px">,an>an style="font-family:微软雅黑, sans-serif;font-size:16px">天然石英晶振,压电水晶振荡子,石英晶体中固体包裹体大部分是围岩碎屑和黄铁矿、金红石等。人造石英晶体的固体包裹体主要是硅酸铁钠an>an style="font-size:16px">( NaFesian>an style="vertical-align:baseline">an style="font-size:16px">2an>an>an style="font-size:16px">Oan>an style="vertical-align:baseline">an style="font-size:16px">6an>an>an style="font-size:16px">.2Han>an style="vertical-align:baseline">an style="font-size:16px">2an>an>an style="font-size:16px">O),an>an style="font-family:微软雅黑, sans-serif;font-size:16px">它是由高压釜内壁被腐蚀脱落的亚铁离子和其它离子an>an style="font-size:16px">,an>an style="font-family:微软雅黑, sans-serif;font-size:16px">与an>an style="font-size:16px">NaOHan>an style="font-family:微软雅黑, sans-serif;font-size:16px">或an>an style="font-size:16px">Naan>an style="vertical-align:baseline">an style="font-size:16px">2an>an>an style="font-size:16px">COan>an style="vertical-align:baseline">an style="font-size:16px">3an>an>an style="font-family:微软雅黑, sans-serif;font-size:16px">溶液和an>an style="font-size:16px">SiOan>an style="vertical-align:baseline">an style="font-size:16px">2an>an>an style="font-family:微软雅黑, sans-serif;font-size:16px">等产生化学反应而形成的。an>
an style="font-family:微软雅黑, sans-serif;font-size:16px"> 胶体包裹体是含钾an>an style="font-size:16px">(K)an>an style="font-family:微软雅黑, sans-serif;font-size:16px">、钠an>an style="font-size:16px">(Na)an>an style="font-family:微软雅黑, sans-serif;font-size:16px">硅酸盐胶体所组成。它是由于石英贴片晶振,<a href="/TCXOcrystal.html" title="温补晶振" target="_blank">温补晶振a>,石英晶体生长过程中an>an style="font-size:16px">,an>an style="font-family:微软雅黑, sans-serif;font-size:16px">温度发生波动时溶液中的二氧化碳达到超饱和状态an>an style="font-size:16px">,an>an style="font-family:微软雅黑, sans-serif;font-size:16px">来不及结晶而形成胶体包裹体。an>
an style="font-family:微软雅黑, sans-serif;font-size:16px"> 气一液包裹体中的液体主要是水溶液、碳酸和其它混合液an>an style="font-size:16px">,an>an style="font-family:微软雅黑, sans-serif;font-size:16px">气体是二氧化碳及挥发性化合物等an>an style="font-size:16px">,an>an style="font-family:微软雅黑, sans-serif;font-size:16px">气一液包裹体多集中在晶体底部包裹体是石英晶振晶体的一种主要缺陷an>an style="font-size:16px">,an>an style="font-family:微软雅黑, sans-serif;font-size:16px">实验表明an>an style="font-size:16px">,an>an style="font-family:微软雅黑, sans-serif;font-size:16px">如果晶片中含有大的针状包裹体时an>an style="font-size:16px">,an>an style="font-family:微软雅黑, sans-serif;font-size:16px">对石英晶体元件的电性能影响很大。an>
an style="font-family:微软雅黑, sans-serif;font-size:16px"> 石英晶体的包裹体可用显微镜观察法或油槽观察法等进行检查an>
an style="font-family:微软雅黑, sans-serif;font-size:16px"> 三、蓝针an>
an style="font-family:微软雅黑, sans-serif;font-size:16px"> 石英晶体中蓝色针状的缺陷称为蓝针。an>
an style="font-family:微软雅黑, sans-serif;font-size:16px"> 蓝针形成的原因很多an>an style="font-size:16px">,an>an style="font-family:微软雅黑, sans-serif;font-size:16px">有人认为蓝针内部包含有铁、锰、铜、锌等金属氧化物an>an style="font-size:16px">,an>an style="font-family:微软雅黑, sans-serif;font-size:16px">在这些氧化物外部还有密集的小气泡或小水珠an>an style="font-size:16px">,an>an style="font-family:微软雅黑, sans-serif;font-size:16px">当光线通过它们时an>an style="font-size:16px">,an>an style="font-family:微软雅黑, sans-serif;font-size:16px">除蓝色光线外an>an style="font-size:16px">,an>an style="font-family:微软雅黑, sans-serif;font-size:16px">其它光都被吸收掉an>an style="font-size:16px">,an>an style="font-family:微软雅黑, sans-serif;font-size:16px">因此在晶体内部呈现蓝色针状缺陷。还有人研究发现an>an style="font-size:16px">,an>an style="font-family:微软雅黑, sans-serif;font-size:16px">存在蓝针的地方有很细的裂缝an>an style="font-size:16px">,an>an style="font-family:微软雅黑, sans-serif;font-size:16px">它与石英晶振,<a href="/OscillatorCrystal.html" title="有源晶振" target="_blank">有源晶振a>晶体原有宏观裂隙平行生长an>an style="font-size:16px">,an>an style="font-family:微软雅黑, sans-serif;font-size:16px">说明蓝针是属于晶体内部机械破坏的结果。an>
an style="font-family:微软雅黑, sans-serif;font-size:16px"> 对一般应用的压电石英晶片可以存在蓝针an>an style="font-size:16px">,an>an style="font-family:微软雅黑, sans-serif;font-size:16px">但用于制造稳定度高的和频率比较高的石英晶体元件时an>an style="font-size:16px">,an>an style="font-family:微软雅黑, sans-serif;font-size:16px">不允许其石英晶片有蓝针存在。an>
an style="font-family:微软雅黑, sans-serif;font-size:16px"> 四、其它疵病an>
an style="font-family:微软雅黑, sans-serif;font-size:16px"> 在一些晶体中an>an style="font-size:16px">,an>an style="font-family:微软雅黑, sans-serif;font-size:16px">可隐隐看出数个晶体的影子an>an style="font-size:16px">,an>an style="font-family:微软雅黑, sans-serif;font-size:16px">这叫幻影或称魔幻。它是由于晶体生长中断了一段时间an>an style="font-size:16px">,an>an style="font-family:微软雅黑, sans-serif;font-size:16px">后来又在晶面上继续结晶而形成的。幻影破坏了晶体格架的完整性an>an style="font-size:16px">,an>an style="font-family:微软雅黑, sans-serif;font-size:16px">影响晶体的弹性an>an style="font-size:16px">,an>an style="font-family:微软雅黑, sans-serif;font-size:16px">属晶体内部深处的缺陷。an>
an style="font-family:微软雅黑, sans-serif;font-size:16px"> 裂隙是存在于晶体内部的小裂缝。它的形成可能是由于生长区中二氧化硅供应不足an>an style="font-size:16px">,an>an style="font-family:微软雅黑, sans-serif;font-size:16px">杂质分布不均匀an>an style="font-size:16px">,an>an style="font-family:微软雅黑, sans-serif;font-size:16px">籽晶不完善an>an style="font-size:16px">,an>an style="font-family:微软雅黑, sans-serif;font-size:16px">机械应力和温度变化不均匀等缘故节瘤是由许多小晶块构成的镶嵌结构an>an style="font-size:16px">,an>an style="font-family:微软雅黑, sans-serif;font-size:16px">其形状像是很小的晶体镶嵌到大晶体的表面。这种镶嵌结构是受温度、压力、溶液饱和程度和混合物数量等生长条件影响而形成。在石英晶振,<a href="/LVDScrystal.html" title="差分晶振" target="_blank">差分晶振a>等石英an>an style="font-family:微软雅黑, sans-serif;font-size:16px">晶体内部某处有集中的许多微小气泡和小裂隙an>an style="font-size:16px">,an>an style="font-family:微软雅黑, sans-serif;font-size:16px">呈现白色如棉花状an>an style="font-size:16px">,an>an style="font-family:微软雅黑, sans-serif;font-size:16px">这种缺陷俗称为棉。an>