Sealing detection method based on pressure solution test

Abstract

The invention discloses a sealing detection method based on a pressure solution test, and belongs to the technical field of quartz crystal resonators. The technical key points are that the method comprises the following steps: S1, carrying out an electrical performance test on a crystal oscillator; s2, the crystal oscillator is placed in a container containing a solution, the solution is FCM-1608, and the temperature of the solution is 100 DEG C; s3, the container is sealed, and then the container is filled with high-pressure gas; s3, soaking the product in the solution for 2-3 hours; s4, releasing the pressure of the container, taking out the product from the solution, and blow-drying the solution on the surface of the crystal oscillator; and S5, after the crystal oscillator is taken out of the solution, performing electrical property detection on the crystal oscillator within 24 hours. The method is used for detecting whether the quartz crystal resonator has the leakage point with the leakage rate of more than 1 * 10 <-8 > mbar.l / s or not.

Description

Technical Field

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

[0002] The sealing test of quartz crystal resonator is an essential process in the manufacturing process of quartz crystal. Poor sealing will greatly reduce the service 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 one is the helium leak detection method (such as CN204128755U, CN207600666U): the crystal oscillator is placed in a vacuum sealed container, and then a certain pressure of helium is filled into the sealed container for a period of time. In this process, if there are holes or cracks in the crystal oscillator, helium will diffuse into the product through these gaps. Finally, the mass spectrometer leak detector detects whether there is a leak through the crystal oscillator. However, this method has the following disadvantages: First, helium has a strong adsorption effect, which will reduce the sensitivity of the mass spectrometer. In addition, in the process of large-scale production, the dichotomy method is used (that is, in large-scale production, in order to pursue efficiency, a certain number of crystals to be tested are generally tested together for leak detection. If a crystal has a sealing defect, the object to be tested needs to be evenly divided and tested again until the defective product is picked out) to find products with defective sealing. In this method, for crystals with defective sealing characteristics, it is easy to exhaust the helium after repeated vacuuming, so that defective products can be judged as good products.

[0005] The second method is to pressurize the liquid and then test the electrical properties (such as CN1414358A). If there are large holes in the crystal oscillator, the solution will invade the interior of the crystal oscillator, and impurities (such as solution, etc.) will be attached to the quartz crystal wafer. The invading solution stops the vibration of the crystal oscillator. The sealing (or other electrical performance indicators) is tested by connecting the crystal oscillator immersed in the solution to the oscillation circuit to check the oscillation frequency.

[0006] The third method is the impedance measurement method (such as JPH1151802A), which tests 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 is above 10%).

[0010] For crystal oscillators, first of all, we must ensure that the solution will not corrode it, and secondly, we must consider 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 mbar·l / s leak points, the detection rate is low. Summary of the invention

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

[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 Leakage points above mbar·l / s include the following steps:

[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 0.45MPa to 0.55MPa;

[0018] S4, the product is immersed in the solution for 2h to 3h;

[0019] S5, the container is depressurized, the product is taken out from the solution and the solution on the surface of the crystal oscillator is blown dry;

[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.

[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 Leakage points above mbar·l / s include the following steps:

[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 0.45MPa to 0.55MPa;

[0026] S4, the product is immersed in the solution for 2h to 3h;

[0027] S5, the container is depressurized, the product is taken out from the solution and the solution on the surface of the crystal oscillator is blown dry;

[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.

[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 crystal oscillator leak detection. As downstream customers' requirements become more and more stringent, further research on the liquid pressurization method is needed.

[0033] Second, the research and development goal of this application is to "detect whether the crystal oscillator has a leakage rate of 1×10 -8 mbar·l / s or more". The "FCM-1608+100℃ immersion" leak detection has the best effect. Through the test, it was found that the change value of the product's electrical performance was larger and more obvious, and the bad phenomenon lasted longer. Within 2 hours of crystal immersion solution, 100% of the products with slight leaks could be detected. It can reduce the phenomenon of missed detection. During the test, it was found that the detection rate of FCM-1608 solution at room temperature and high temperature of 60° in 30min-2h did not show a particularly high advantage compared with alcohol / 25℃. Therefore, FCM-1608 / 100° has a leakage rate of 1×10 within 24h. -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 in conjunction with 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 a variety of different forms and should not be construed as being limited to the embodiments described herein. It is believed 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 labels will be used throughout to represent the same or similar elements.

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

[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 of the current sealing test scheme using pressure solution (such as water, ethanol, etc.) is that the pressure solution cannot be completely attached to the wafer, and the electrical characteristic parameters 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 there are two main factors that cause this problem:

[0044] First, the solution is not permeable enough; when the leakage point of the product is small, the solution cannot penetrate into the interior of 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: The existing technology has strict requirements on the detection time, generally limiting it to within 2 hours after the crystal oscillator is taken out of the solution. However, due to the limitation of detection capacity, it may lead to the problem of failure to detect in time.

[0047] The main reason for the above problems is that the time after pressing is too long, and the solution evaporates, which will cause 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 shall be 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 so that the gas pressure in the container is 0.45MPa to 0.55MPa;

[0056] S4, the product is soaked 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, judging whether defective products can be identified based on the electrical performance test results of S1 and S6.

[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 Table 1 to Table 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). For leakage rates of 10 - 8 The detection rate of leaks with a pressure of mbar·l / s cannot reach 100%. In particular, at room temperature, the detection rate of FCM-1608 solution is not better than that of alcohol.

[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 30min-2h 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 100°C, the leakage rate is 10 -8 The detection rate of leak points and 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 time, and its performance is good.

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

Claims

1. A sealing detection method based on pressure solution testing, characterized in that: Used to detect whether the quartz crystal resonator has a leakage rate greater than 1×10 -8 Leakage points above mbar·l / s include the following steps: 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 0.45MPa to 0.55MPa; S4, the product is immersed in the solution for 2h to 3h; S5, the container is depressurized, the product is taken out from the solution and the solution on the surface of the crystal oscillator is blown dry; 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.

2. A sealing 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. A sealing detection method based on pressure solution testing, characterized in that: Used to detect whether the quartz crystal resonator has a leakage rate greater than 1×10 -8 Leakage points above mbar·l / s include the following steps: S1, test the electrical performance of the crystal oscillator; 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; S3, sealing the container, and then filling the container with high-pressure gas so that the gas pressure in the container is maintained at 0.45MPa to 0.55MPa; S4, the product is immersed in the solution for 2h to 3h; S5, the container is depressurized, the product is taken out from the solution and the solution on the surface of the crystal oscillator is blown dry; 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.

4. A sealing detection method based on pressure solution testing according to claim 3, characterized in that: In S6, the electrical performance of the crystal oscillator is tested within 30 minutes to 2 hours.

5. The sealing detection method based on pressure solution test according to any one of claims 1 to 4, characterized in that: The electrical performance test is a temperature-frequency characteristic test of the crystal oscillator.

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