Basic tone crystals with high frequencies are in great demand, especially for wireless applications in the Internet of Things industry. More and more often we find devices communicating with each other and exchanging data via radio, for example via Bluetooth, ZigBee or ISM. All these radio standards use frequency bands in the three-digit megahertz or gigahertz range. To generate these RF frequencies, the devices require very precise reference crystals with frequencies in the range from about 20 to 52 megahertz.

高频晶体（基频）的需求量很大，特别是对于物联网行业的无线应用。我们发现越来越多地设备通过无线电（例如通过蓝牙、ZigBee 或 ISM）相互通信和交换数据。所有这些无线电标准都使用三位数兆赫兹或千兆赫兹范围内的频段。为了产生这些射频频率，这些器件需要频率在约 20 至 52 兆赫兹范围内的非常精确的参考晶体。

Requirements in the Wireless Industry: Ultra-Thin and Highly Precise  无线行业的要求：超薄和高精度

Quartz crystals with such a high resonant frequency must be ultra-thin. The thicker the quartz, the lower its frequency and the less suitable it is for wireless applications.

具有如此高谐振频率的石英晶体必须是超薄的。石英越厚，其频率越低，越不适合无线应用。

A whole series of production steps are necessary to produce sufficiently thin quartz discs. The raw crystal block is gradually divided into ever smaller units. The smallest unit is ultimately the “blank”, which is sawn, ground, etched and polished to produce the correct thickness and a particularly smooth surface. For example, to produce a quartz blank with a resonant frequency of 40 megahertz, the quartz disk must have a thickness of only 41.5 micrometers.

生产足够薄的石英晶片需要一系列的生产步骤。原始晶块逐渐被分成越来越小的单元。最小的单位最终是“毛坯”，它经过锯切、研磨、蚀刻和抛光，以产生正确的厚度和特别光滑的表面。例如，要生产谐振频率为40兆赫兹的石英毛坯，石英晶片的厚度必须仅为 41.5 微米。

Due to its nominal frequency of 40 megahertz, this quartz disk would already be ideally suited for use in wireless applications; but it’s not that simple. In addition to the quite high nominal frequency, a minimum error tolerance in the ppm range (ppm = parts per million) is required. Such high precision is necessary because the radio frequencies of the individual channels are very close to each other, especially in the high-frequency range. If you want to avoid an overlapping of the different radio frequencies, you must ensure the lowest frequency tolerance of the underlying reference frequency.

由于其标称频率为40兆赫兹，该石英晶片已经非常适合用于无线应用；但事情并没有那么简单。除了相当高的标称频率外，还需要ppm范围内的最小误差容限（ppm = 百万分之一）。如此高精度是必要的，因为各个信道的无线电频率彼此非常接近，尤其是在高频范围内。如果要避免不同无线电频率重叠，则必须确保原始参考频率的最低频率容差。

This poses a challenge for crystal production, which can be illustrated using the example of the 40-megahertz crystal. As mentioned above, the quartz disc ideally has a nominal thickness of exactly 41.5 micrometers. With a target error tolerance of only ±10 ppm, the actual value may deviate from this ideal value by a maximum of ±0.415 nanometers. This is less than a millionth of a millimeter.

这给晶体生产带来了挑战，以40兆赫兹晶体的例子来说明这一点。如上所述，理想情况下，石英晶片的标称厚度恰好为41.5微米。由于目标容错率仅为±10ppm，实际值可能与该理想值最多相差±0.415 纳米，这实际上不到百万分之一毫米。

Such an accuracy in the sub-nanometer range cannot be achieved by mechanical production steps alone. Quartz manufacturers react to this problem by producing their crystals minimally too thick or too thin from the outset, depending on the properties of the production plant. The crystals are then fine-tuned to achieve the desired nominal frequency.

亚纳米范围内的这种精度仅靠机械生产步骤是无法实现的。石英制造商从一开始就通过改变晶体的厚度来应对这个问题，然后对晶体进行微调以达到所需的标称频率。

Fine Tuning: Post-Evaporation or Ion Bombardment 微调：蒸发后或离子轰击

One of the last processing steps in quartz production is the application of an electrode on both sides of the quartz disc. This electrode is necessary to electrically excite the oscillation of the blank. At the same time, this electrode is also the starting point for the following two processes for fine-tuning the quartz.

石英晶体生产的最后加工步骤之一是在石英晶片的两侧增加电极。该电极是电激发晶片振荡所必需的。同时，该电极也是以下两个微调石英工艺的起点。

1) Post Evaporation / Sputtering: 后蒸发/溅射

To be able to use the post-evaporation process – also called “sputtering” – the quartz disc is manufactured slightly too thin, so that even after the electrode has been applied, the resonance frequency is minimally too high. To correct this, the quartz electrode is evaporated with silver. In this way, an ultra-thin layer of silver is applied, which increases the mass of the quartz and lowers its frequency. During the process, the frequency of the quartz disc is continuously measured. If the desired nominal frequency is reached, the post-evaporation is stopped immediately.

为了能够使用后蒸发工艺（也称为“被银溅射”），石英晶片厚度特意制造的略微过薄，因此即使在施加电极后，共振频率也会轻微过高。为了纠正这个问题，我们对石英电极采取增加被银工序。通过这种方式，为其涂上一层超薄的银，从而增加石英晶片的质量并降低其频率。在此过程中，通过仪器连续测量石英晶片的频率。如果达到所需的标称频率，则立即停止喷银任务。

2) Adjustment by Ion Bombardment  离子轰击调整

The prerequisite of the quartz disc produced slightly too thick means even after the electrode has been applied, the resonance frequency is still slightly too low. In this case, the mass of the electrode is reduced by targeted bombardment with ions of sufficiently high energy. By reducing the mass, the frequency increases continuously. As with sputtering, the frequency is monitored throughout the entire process. The process ends as soon as the desired nominal frequency is reached.

石英晶片产生的先决条件稍厚，意味着即使在施加电极后，谐振频率仍然略低。在这种情况下，电极的质量通过用足够高能量的离子进行有针对性的轰击来减少。通过减小质量，频率不断增加。与溅射一样，在整个过程中都监控频率。一旦达到所需的标称频率，该过程就会结束。

Genuway Crystals for All Wireless Applications 适用于所有无线应用的晶诺威晶体

Thanks to these two fine-tuning processes, ultra-thin and high precision crystals can be manufactured for a wide variety of wireless applications. The SMD2016 and SMD1612 models are also produced in this way. Available in the frequency range from 16 to 96 megahertz, with a fault tolerance of only ±10 ppm and particularly high frequency stability, these crystals are specially designed for use in wireless devices.

由于通过这两种微调工艺可以制造出用于各种无线应用的超薄和高精度晶体，SMD2016和SMD1612型号也是这样生产的。这些晶体的频率范围为16至96 兆赫兹，容错率仅为±10 ppm，频率稳定性特别高，专为无线设备而设计。