6MHz-14MM-Silver-Aluminum Alloy Crystal
Part No：SA6AD14
This 6MHz, 14mm silver-aluminum alloy electrode quartz crystal is specifically designed for high-precision thin film deposition monitoring. By combining a 6MHz base frequency with a 14mm large effective area, it provides a wider measurement range while ensuring stability. The silver-aluminum alloy electrode not only maintains the high conductivity of silver but also effectively enhances wear resistance and oxidation resistance through aluminum doping. Compared to pure gold electrodes, the silver-aluminum alloy possesses better mechanical ductility, allowing it to effectively buffer the mechanical stress generated by deposited thin films and reduce stress transmission to the quartz substrate. This characteristic makes it perform exceptionally well in applications involving high-stress materials or long-term continuous deposition, significantly reducing frequency-hopping risks and ensuring high reliability in monitoring.
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14mm-6MHz Silver-Aluminum Alloy Precision Monitoring Crystal: Optimized for High-Stress and Complex Deposition Processes
The SA6AD14 is a 6MHz quartz crystal designed for high-stress thin film deposition and complex multi-layer thin film growth. Featuring a large 14mm electrode design, it provides a wider effective measurement area. Its core advantage lies in the innovative silver-aluminum alloy electrode coating: it retains the excellent conductivity of silver while significantly improving oxidation resistance and mechanical ductility through aluminum alloying. Compared to traditional pure gold electrodes, this model absorbs internal film stress more effectively, extending the service life of the crystal in demanding production environments.
Process Advantages of Silver-Aluminum Alloy Electrodes
Superior Stress Buffering: The silver-aluminum alloy electrode possesses excellent flexibility, effectively buffering mechanical stress generated during film deposition and reducing stress transmission to the quartz substrate, thereby mitigating frequency-hopping risks at the source. Outstanding Oxidation Stability: Aluminum doping effectively enhances the corrosion resistance of the electrode surface. It maintains a low and stable resonance resistance (≤15Ω) even after long-term vacuum exposure or multiple high-temperature thermal cycles, ensuring precise data acquisition. High-Compatibility Conductive Layer: While maintaining a high-performance conductive channel, the electrode exhibits excellent adhesion to various complex deposition materials, making it particularly suitable for stress-sensitive optical coating and composite film growth monitoring.
Why Choose the 6MHz 14mm Series?
The 6MHz frequency configuration achieves an ideal balance between sensitivity and substrate thickness, making it the preferred choice for precise optical film and multi-layer film monitoring. The 14mm diameter design effectively expands the sensor's detection window, improving deposition uniformity while providing wider tolerance for sensor probe alignment and installation. Whether used for high-precision anti-reflective optical coatings, dielectric film monitoring, or semiconductor thin film processes requiring resilience against harsh stress variations, the SA6AD14 provides durable and reliable monitoring performance for vacuum coating production lines.
Product Specifications
| Part No | SA6AD14 |
| Nominal Frequency | 6.000MHz |
| Center Frequency | 5.988MHz |
| Frequency Tolerance | ±8KHz@25°C |
| Wafer Diameter | 13.97mm ± 0.03mm |
| Resonance Resistance | ≤15Ω |
| Crystal Cutting | AT-CUT |
| Electrode Material | Silver/Aluminum |
| Operating Temperature | 25°C ~ 75°C |
| Electrode Appearance | Dual-anchor electrode (2 anchors) |
| Storage Temperature | -20°C ~ +85°C |
| Storage Humidity | Relative humidity 30~50% |
| Storage Life | 6 months |
applications of the quartz monitor crystal
Find answers to the most frequently asked questions .
Although pure gold electrodes have good chemical stability, their high hardness tends to couple mechanical stress from the deposited film directly to the quartz substrate, leading to frequent frequency hopping. The SA6AD14’s silver-aluminum alloy electrode features unique micro-lattice flexibility, acting as a 'stress-absorbing buffer layer' that effectively attenuates film tension, thereby ensuring signal continuity in high-stress environments.
The large 14mm effective area significantly reduces frequency instability caused by edge effects and provides a wider measurement window. This large-size design optimizes energy distribution; combined with the 6MHz base frequency, it not only offers higher sensitivity for initial thickness detection but also withstands greater loading during long-term thick film deposition without losing resonance.
No. The SA6AD14 uses a specialized alloy proportioning process, where the addition of aluminum forms an extremely thin and stable passivation layer on the silver surface. This gives the product both the high conductivity of silver and anti-oxidation capabilities far superior to pure silver, ensuring resistance stability throughout vacuum exposure cycles.
Low frequency is usually related to installation pressure or ambient temperature. For 14mm crystals, excessive pressure from the probe spring can cause uneven stress on the quartz edge, leading to initial frequency offsets. We recommend ensuring light contact with the probe pins and performing a short 'pre-deposition' before critical experiments to allow the crystal to reach thermal equilibrium.
Yes, it is highly suitable. The SA6AD14 is designed for high-frequency process transitions. The mechanical strength of the silver-aluminum alloy allows it to withstand pressure swings from 10⁻⁷ Torr to atmospheric pressure, while its excellent adhesion ensures that the electrode layer does not peel or delaminate due to thermal shock.
Consistency in monitoring depends on the stability of the resonance resistance (R-value). The SA6AD14 strictly controls the operating resistance to below 15Ω with minimal fluctuations over its entire lifespan. This ensures that the controller can always lock onto high-SNR oscillation signals, avoiding 'false thickness deviations' caused by impedance spikes, ensuring every batch has consistent film thickness.
If you frequently encounter the following phenomena: premature crystal failure, sawtooth-like jumps in data curves, or the monitoring probe losing signal after the film reaches a certain thickness, these are often signs that high-stress films are damaging the quartz substrate. Switching to the SA6AD14 with its stress-buffering properties can often resolve these issues immediately.