JJK 5MHz-12MM-Dual Anchor Silver/Aluminum Alloy Monitor Crystal
Part No：SA5AD12
SA5AD12 is a high-performance 5MHz quartz monitor crystal designed specifically for **long-cycle and high-load deposition tasks**. Its core advantage lies in the unique **Silver/Aluminum (Ag/Al) alloy electrode** structure, which inherits the exceptional oscillation sensitivity of silver while utilizing aluminum's chemical inertness to effectively suppress oxidation and sulfuration in both atmospheric and vacuum residual gases. For the precise 12.42mm specification, we employ a high Q-value AT-cut process combined with a **2-Anchor** electrode design, ensuring superior frequency stability and a broader mass-load tolerance at the lower 5MHz base frequency. It is an ideal high-cost-performance benchmark for balancing measurement precision and service life in thick-film optical coating and metallization processes.
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SA5AD12 5MHz Dual-Anchor Alloy Crystal: A Reliable Solution for Thick-Film High-Precision Monitoring
In precision coating processes, 5MHz crystals offer significantly higher mass-load capacity than 6MHz variants. The SA5AD12 leverages this physical property with a 12.42mm precision diameter, tailored for PVD processes requiring long-term continuous monitoring. The 5.000MHz nominal frequency combined with the 4.977MHz scientifically designed center frequency reserves ample linear workspace for subsequent film deposition. The dual-anchor electrode structure further optimizes the mechanical contact force distribution between the 12mm crystal and sensor probe clips, effectively resolving signal noise issues often caused by small contact areas.
Dual-Anchor Electrode Technology: Perfect Balance Between Conductivity and Oxidation Resistance
The electrode layer of SA5AD12 is not a simple metal stack but a Silver/Aluminum alloy formed through precision sputtering. Silver's high conductivity ensures an ultra-low resonance resistance (≤15Ω) for rapid and stable oscillation even under low power; meanwhile, aluminum atoms form a dense passivation layer on the electrode surface, significantly enhancing corrosion resistance during storage and use. The '2-Anchor' design provides redundant signal paths, ensuring stable ohmic contact even if probe holders undergo thermal deformation over time, thereby reducing the risk of frequency hopping.
Optimized for 12mm Precision Systems: Improving Yield with Superior Thermo-Mechanical Stability
Strictly adhering to the 12.42mm (±0.03mm) industrial tolerance, SA5AD12 perfectly matches Shincron, Optorun, and other Japanese or domestic high-precision 12mm sensor probes. Its AT-CUT angle is strictly tuned for thermal drift compensation, effectively offsetting frequency drift within the typical 25°C to 75°C coating temperature range. The low stress sensitivity of the 5MHz frequency, combined with the optimized surface energy of the alloy, significantly improves adhesion between the film and the crystal. This comprehensive performance boost directly reduces unexpected 'Crystal Fail' rates, saving customers high material and time costs.
SA5AD12 Technical Specifications
| Part No | SA5AD12 |
| Nominal Frequency | 5.000MHz |
| Center Frequency | 4.977MHz |
| Frequency Tolerance | ±7KHz@25°C |
| Wafer Diameter | 12.42mm ± 0.03mm |
| Resonance Resistance | ≤15Ω |
| Crystal Cutting | AT-CUT |
| Electrode Material | Silver/Aluminum (Ag/Al) |
| Operating Temperature | 25°C ~ 75°C |
| Electrode Appearance | 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 .
Pure silver electrodes have excellent conductivity but tarnish easily in humid or sulfur-containing air and can migrate under vacuum. The Ag/Al alloy in SA5AD12 maintains low impedance while utilizing aluminum's oxidation resistance to form self-protection, extending shelf life and preventing signal interruptions caused by electrode oxidation during high-temperature coating.
5MHz crystals have a thicker quartz substrate, providing higher physical strength and a smaller frequency shift per unit of film thickness due to the lower base frequency. This means that for thick film deposition (such as fluorides or sulfides), SA5AD12 supports longer monitoring times before reaching the failure point, making it the preferred choice for 'long-life' processes.
This is a pre-compensation design for thick electrode processes. The Ag/Al alloy electrodes have mass that shifts the quartz substrate's frequency downward. Setting the center frequency at 4.977MHz ensures the crystal starts in its most stable linear resonance zone (Q-value) upon installation. Users simply set the controller to 5.000MHz, and the system captures the frequency for a smoother initial rate curve.
The dual-anchor design provides two symmetrical contact areas, increasing installation flexibility. Compared to single-sided or fully covered electrodes, dual anchors better guide stress release and reduce physical deformation under the pressure of the probe's tightening nut. Ensure the probe leaf spring presses on either anchor area to achieve ultra-low contact resistance.
5MHz AT-cut crystals are inherently less sensitive to stress. Additionally, the Ag/Al alloy layer possesses a certain degree of plasticity, acting as a buffer to absorb mechanical stress from the film. This prevents peeling or cracking of the film on the crystal surface, thereby suppressing 'Mode Hopping' common in late-stage deposition.
While the alloy electrode is oxidation-resistant, we use vacuum aluminum foil packaging. It is recommended to store crystals in a dry cabinet (humidity <40%). Since 5MHz crystals are sensitive to environmental mass-loading, avoid touching the electrode surface directly with hands after opening to prevent oily residues from increasing the R1 resistance.
Yes. The 12.42mm diameter of SA5AD12 is specifically designed to fit 12mm sensors from equipment such as Shincron and Optorun. It can directly replace original 5MHz 12mm crystals in these machines, often providing superior electrode durability.