A sealing detection method based on pressure solution test

Abstract

The application discloses a sealing detection method based on pressure solution test, and belongs to the technical field of quartz crystal resonators; the technical points are as follows: S1, performing electrical performance test on the crystal oscillator; S2, placing the crystal oscillator in a container containing a solution, wherein the solution is FCM-1608, and the temperature of the solution is 100 DEG C; S3, sealing the container, then filling the container with high-pressure gas; S3, immersing the product in the solution for 2h-3h; S4, discharging the container, taking out the product from the solution, and blowing the solution on the surface of the crystal oscillator dry; S5, performing electrical performance test on the crystal oscillator within 24h after the crystal oscillator is taken out from the solution. The above method is used for detecting whether the quartz crystal resonator has a leak point with a leak rate greater than 1x10 ‑8 mbar*l / s.

Description

Technical Field

[0001] The present invention relates to the technical field of quartz crystal oscillators, and more particularly to a sealing detection method based on pressure solution testing. Background Art

[0002] Testing the sealing of quartz crystal resonators is an essential process in the manufacturing of quartz crystals. Poor sealing can significantly reduce the life of the component, cause abnormalities during operation, and in severe cases, cause the quartz crystal to stop working (stop oscillating).

[0003] In this field, there are mainly two technical routes:

[0004] The first method, helium leak detection (e.g., CN204128755U and CN207600666U), involves placing a crystal oscillator in a sealed, vacuum-sealed container. The container is then filled with helium at a certain pressure for a period of time. During this process, if there are leaks or cracks in the crystal oscillator, helium will diffuse through these gaps into the product. Finally, a mass spectrometer leak detector uses the crystal oscillator to detect leaks. However, this method has several drawbacks: first, helium has a strong adsorption effect, which can reduce the sensitivity of the mass spectrometer. Furthermore, during large-scale production, a binary method is often used (i.e., in large-scale production, for efficiency reasons, a certain number of crystals to be tested are generally tested together for leaks. If a crystal has a sealing defect, the sample is evenly divided and tested again until a defective product is identified) to identify products with sealing defects. This method, through repeated vacuuming, easily depletes the helium from crystals with sealing defects, thus qualifying defective products as good.

[0005] The second method involves injecting liquid and then testing the electrical properties (e.g., CN1414358A). If there are large pores in the crystal oscillator, the solution will intrude into the interior of the crystal oscillator, and impurities (such as the solution) will adhere to the quartz crystal wafer. The intruding solution will stop the crystal oscillator from vibrating. The sealing (or other electrical performance indicators) can be tested by connecting the crystal oscillator immersed in the solution to an oscillation circuit to check the oscillation frequency.

[0006] The third method is the impedance measurement method (e.g. JPH1151802A), which measures the impedance change of the piezoelectric element by changing the ambient air pressure of the crystal oscillator.

[0007] For the liquid pressurization method (i.e. the second technical route), the solutions are mainly the following:

[0008] 1) CN1414358A: Inorganic solvents including water, organic solvents including ethanol;

[0009] 2) KR20120003644A: salt solution (salt concentration above 10%).

[0010] For crystal oscillators, the first thing to do is to ensure that the solution does not corrode it, and the second thing to consider is the impact on the environment. Based on this, fluorinated liquid becomes a possibility.

[0011] However, the existing detection methods use ethanol, fluorinated solution, or other solutions. The R&D team found in production practice that: -8 When testing for leaks at mbar·l / s, the detection rate is low. Summary of the Invention

[0012] The purpose of the present invention is to address the deficiencies of the above-mentioned prior art and provide a sealing detection method based on pressure solution testing.

[0013] The technical solution of this application is:

[0014] A seal detection method based on pressure solution test is used to detect whether a quartz crystal resonator has a leakage rate greater than 1×10 -8 For leaks above mbar·l / s, the following steps are included:

[0015] S1, test the electrical performance of the crystal oscillator;

[0016] S2, placing the crystal oscillator in a container containing a solution, wherein the solution is FCM-1608 and the temperature of the solution is 100°C;

[0017] S3, sealing the container, and then filling the container with high-pressure gas so that the gas pressure in the container is maintained at 0.45 MPa to 0.55 MPa;

[0018] S4, soak the product in the solution for 2h~3h;

[0019] S5, depressurize the container, remove the product from the solution and blow dry the solution on the surface of the crystal oscillator;

[0020] S6, after the crystal oscillator is taken out of the solution, the electrical performance of the crystal oscillator is tested within 24 hours; by comparing the electrical performance data obtained in step S1 with the electrical performance data obtained in S6, it is determined whether there is a leak point.

[0021] Furthermore, in S6, the electrical performance of the crystal oscillator is tested within 30 minutes to 24 hours.

[0022] A seal detection method based on pressure solution test is used to detect whether a quartz crystal resonator has a leakage rate greater than 1×10 -8 For leaks above mbar·l / s, the following steps are included:

[0023] S1, test the electrical performance of the crystal oscillator;

[0024] S2, placing the crystal oscillator in a container containing a solution, wherein the solution is DA-328 and the temperature of the solution is 100°C;

[0025] S3, sealing the container, and then filling the container with high-pressure gas so that the gas pressure in the container is maintained at 0.45 MPa to 0.55 MPa;

[0026] S4, soak the product in the solution for 2h~3h;

[0027] S5, depressurize the container, remove the product from the solution and blow dry the solution on the surface of the crystal oscillator;

[0028] S6, after the crystal oscillator is taken out of the solution, the electrical performance of the crystal oscillator is tested within 2 hours; by comparing the electrical performance data obtained in step S1 with the electrical performance data obtained in S6, it is determined whether there is a leak point.

[0029] Furthermore, in S6, the electrical performance of the crystal oscillator is tested within 30 minutes to 2 hours.

[0030] Furthermore, the electrical performance test is a temperature-frequency characteristic test of the crystal oscillator.

[0031] The beneficial effects of this application are:

[0032] First, the liquid pressurization method is a technical route for leak detection of crystal oscillators. As downstream customers' requirements become increasingly stringent, further research on the liquid pressurization method is needed.

[0033] Second, the research and development goal of this application is to “detect whether there is a crystal oscillator with a leakage rate of 1×10 -8 mbar·l / s or above. "FCM-1608 + 100°C immersion" leak detection is the most effective. Through testing, it was found that the changes in the product's electrical performance were greater and more obvious, and the adverse phenomena lasted longer. Within 2 hours of crystal immersion in the solution, 100% of products with slight leaks could be detected. This can reduce the phenomenon of missed detection. During testing, it was found that the FCM-1608 solution at room temperature and high temperature of 60°C did not show a particularly high detection rate in the 30min-2h period compared to alcohol / 25°C. Therefore, FCM-1608 / 100°C has a detection rate of 1×10 within 24 hours. -8 The detection rate of leaks above mbar·l / s can be maintained at 100%, and the effect is significantly improved and unpredictable. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The present invention will be further described in detail below with reference to the embodiments in the accompanying drawings, but this does not constitute any limitation to the present invention.

[0035] Figure 1This is a comparison chart of the detection rate results of the six schemes about 30 minutes after the test.

[0036] Figure 2 This is a comparison chart of the detection rate results of the six schemes about 2 hours after the test.

[0037] Figure 3 This is a comparison chart of the detection rate results of the six schemes about 4 hours after the test.

[0038] Figure 4 This is a comparison chart of the detection rate results of the six schemes about 24 hours after the test. DETAILED DESCRIPTION

[0039] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. However, the present disclosure may be embodied in many different forms and should not be construed as limited to the embodiments described herein. It is understood that these embodiments are provided to make the present disclosure more thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art. In the drawings, the shapes and sizes of elements may be exaggerated for clarity, and the same drawings and reference numerals will be used throughout to represent the same or similar elements.

[0040] <Example 1: A seal detection method based on pressure solution testing>

[0041] <1. R&D Difficulties and R&D Ideas>

[0042] Difficulty 1: To detect whether the crystal oscillator has a leakage rate of 10 -8 The main problem with current sealing solutions using pressure solutions (such as water, ethanol, etc.) is that the pressure solution cannot completely adhere to the wafer, and the electrical characteristics of the crystal will not change significantly.

[0043] The main issue is why the injected solution cannot adhere to the wafer. The R&D team believes that the following two factors are the main factors causing this problem:

[0044] First, the solution's permeability is insufficient; when the product's leak point is small, the solution cannot penetrate into the product when the product is soaked.

[0045] Second, the solution enters the interior of the product, but the solution's cohesiveness is insufficient and its adhesion to the wafer is too poor.

[0046] Difficulty 2: Existing technologies have strict requirements for detection time, generally limiting it to within 2 hours after the crystal oscillator is removed from the solution. However, due to limitations in detection capabilities, timely detection may not be possible.

[0047] The main reason for the above problems is that the test is left for too long after pressing, and the evaporation of the solution will lead to distortion of the results.

[0048] <2. Experimental Research>

[0049] Test conditions:

[0050] (1) Collect defective products.

[0051] (2) Before the test, the electrical properties of the defective products are tested.

[0052] (3) Test steps:

[0053] S1, conduct electrical performance test on the collected defective products

[0054] S2, placing the product in a container containing a solution, and the solution is maintained at a certain temperature;

[0055] S3, sealing the container, and then filling the container with high-pressure gas to make the gas pressure in the container between 0.45 MPa and 0.55 MPa;

[0056] S4, soak the product in the solution for 2 to 3 hours;

[0057] S5, depressurize and release the air from the container to remove the product from the solution; then blow dry the solution on the surface of the product to avoid affecting the test;

[0058] S6, electrical performance test was performed 30 minutes, 2 hours, 4 hours, and 24 hours after the test;

[0059] S7, based on the electrical performance test results of S1 and S6, determines whether defective products can be identified.

[0060] (4) Test plan and test results

[0061] In the test plan, several products with known leakage points were selected for testing.

[0062] This application mainly compares the results of three solutions: FCM-1608, alcohol, and DA-328 at different temperatures. The test results are shown in Table 1.

[0063] Table 1

[0064]

[0065] It should be noted that:

[0066] FCM-1608: Purchased from Zhejiang Yongtai Fluoro Technology Co., Ltd.

[0067] DA-328: Purchased from Guangzhou Jinhong Chemical Raw Materials Co., Ltd.

[0068] The unit of leakage rate in Tables 1 to 4 is mbar·l / s

[0069] From Table 1-4 we can see that:

[0070] (1) At room temperature, the solution is DA-328 or FCM-1608, alcohol, 30 minutes to 2 hours after the test (the current standard requires the comparison of electrical performance within 2 hours after the test, so the focus is on 30 minutes and 2 hours for comparison). - 8 The detection rate of leaks with a pressure of mbar·l / s could not reach 100%. In particular, the detection rate of FCM-1608 solution was not better than that of alcohol at room temperature.

[0071] (2) When the temperature of FCM-1608 solution was selected at 60°, its detection effect did not show a particularly high advantage compared with alcohol / 25°C, and the detection rate 30 minutes to 2 hours after the test did not show a particularly high advantage.

[0072] (3) When the solution is FCM-1608 or DA-328 and the temperature is set to 100°C, the leakage rate is 10 -8 The detection rate of leak points with a flow rate of mbar·l / s has been significantly improved.

[0073] (4) FCM-1608 / 100° is the best solution, which can still maintain a 100% detection rate after 24 hours of pressing, and its performance is good.

[0074] The above embodiments are preferred implementation modes of the present invention and are only used to facilitate the explanation of the present invention. They are not intended to limit the present invention in any form. Any person with ordinary knowledge in the technical field can, without departing from the scope of the technical features of the present invention, make partial changes or modifications to the technical contents disclosed in the present invention and make equivalent embodiments without departing from the technical features of the present invention. Such modifications still fall within the scope of the technical features of the present invention.

Claims

1. A seal detection method based on pressure solution test, characterized in that: Used to detect whether the quartz crystal resonator has a leakage rate greater than 1×10 -8 For leaks above mbar·l / s, the following steps are included: S1, test the electrical performance of the crystal oscillator; S2, placing the crystal oscillator in a container containing a solution, wherein the solution is FCM-1608 and the temperature of the solution is 100° C.; S3, sealing the container, and then filling the container with high-pressure gas so that the gas pressure in the container is maintained at 0.45 MPa to 0.55 MPa; S4, soak the product in the solution for 2h~3h; S5, depressurize the container, remove the product from the solution and blow dry the solution on the surface of the crystal oscillator; S6, after the crystal oscillator is taken out of the solution, the electrical performance of the crystal oscillator is tested within 24 hours; by comparing the electrical performance data obtained in step S1 with the electrical performance data obtained in S6, it is determined whether there is a leak point.

2. A seal detection method based on pressure solution testing according to claim 1, characterized in that: In S6, the electrical performance of the crystal oscillator is tested within 30 minutes to 24 hours.

3. The seal detection method based on pressure solution test according to claim 1 or 2, characterized in that: The electrical performance test is a temperature-frequency characteristic test of the crystal oscillator.

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