Crystal Oscillator Frequency Vacuum Testing Module and Device
By using a thermally conductive insulating sleeve and a water-cooling system in the crystal oscillator frequency vacuum test module, the problem of slow probe cooling speed in a high vacuum environment was solved, and high-precision frequency testing was achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SHENZHEN XINYIJING TECH CO LTD
- Filing Date
- 2025-07-08
- Publication Date
- 2026-06-30
AI Technical Summary
When testing crystal oscillator frequencies in a high vacuum environment, the heat from the probe cannot be effectively cooled, leading to a decrease in testing accuracy, especially when fine-tuning the frequency, resulting in significant deviations.
A thermally conductive insulating sleeve is used to conduct the heat of the probe to the metal block, and water cooling is used to dissipate heat from the metal block. The metal block forms a Faraday cage effect to shield electromagnetic interference and improve test accuracy.
Effective probe cooling improves the accuracy of frequency testing, reduces errors caused by electromagnetic interference, and ensures test accuracy within ±1ppm.
Smart Images
Figure CN224436442U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of crystal oscillator technology, and in particular to a crystal oscillator frequency vacuum testing module and device. Background Technology
[0002] The interior of a finished crystal oscillator is in a high vacuum state. To ensure testing accuracy, frequency testing needs to be performed in a vacuum chamber during fine-tuning (micro-tuning) of a semi-finished crystal oscillator. Fine-tuning requires significantly higher frequency testing accuracy than coarse-tuning because it is the final frequency tuning process. Therefore, the accuracy of frequency testing in a vacuum is particularly important during fine-tuning, often requiring an accuracy within ±1ppm. The probe heats up during testing. In the atmosphere, convection cooling, radiation cooling, and solid-state heat transfer cooling are possible, and the probe's heating rate is roughly equal to its cooling rate. However, in a high vacuum, air is scarce, convection cooling is virtually nonexistent, and radiation cooling only cools a very small portion of the heat. Cooling relies solely on solid-state heat transfer. The limited contact between the probe and the solid metal results in a cooling rate far lower than the probe's heating rate, causing the probe to stabilize at hundreds of degrees Celsius after several hours of operation. This leads to a significant deviation between the tested frequency and the frequency at room temperature. Utility Model Content
[0003] The technical problem to be solved by this utility model embodiment is to provide a crystal oscillator frequency vacuum testing module and device to improve testing accuracy.
[0004] To address the aforementioned technical problems, this utility model provides a crystal oscillator frequency vacuum testing module, comprising a metal block, a probe welding circuit board, and several probe assemblies. The probe welding circuit board is disposed on the metal block, and the probe assemblies are spaced apart on the metal block. Each probe assembly includes a probe sleeve and a thermally conductive insulating sleeve fitted onto the probe sleeve. Probes are inserted into both the upper and lower ends of the probe sleeve, and the upper end of the probe sleeve is welded to the probe welding circuit board. A circulating water channel is provided inside the metal block.
[0005] Furthermore, the bottom of the metal block is provided with a probe positioning block for fixing the lower end of the probe sleeve.
[0006] Furthermore, it also includes a frequency test board, which is electrically connected to the probes at the lower end of the probe sleeve.
[0007] Furthermore, the thermally conductive insulating sleeve is a thermally conductive silicone sleeve.
[0008] Furthermore, the top of the probe located at the upper end of the probe sleeve is flush with the top of the probe, and the bottom of the probe located at the lower end of the probe sleeve is flush with the bottom of the probe.
[0009] Furthermore, all the probe sleeves are perpendicular to the probe welding circuit board.
[0010] Accordingly, this utility model embodiment also provides a crystal oscillator frequency vacuum testing device, including a vacuum chamber, an external return water pipe, an external inlet water pipe, an internal return water pipe, an internal inlet water pipe, and the aforementioned crystal oscillator frequency vacuum testing module. The crystal oscillator frequency vacuum testing module is disposed in the vacuum chamber, and the external return water pipe and the external inlet water pipe are located outside the vacuum chamber. The external return water pipe and the external inlet water pipe are respectively connected to the return end and the inlet end of the circulating water channel inside the metal block through the internal return water pipe and the internal inlet water pipe.
[0011] Furthermore, sealing joints are provided on the inner and outer sides of the vacuum chamber and on the metal block. The inner return water pipe and the outer return water pipe, the return water end of the circulating water channel, and the inner inlet water pipe and the outer inlet water pipe, the inlet water end of the circulating water channel are all connected by sealing joints.
[0012] The beneficial effects of this utility model are as follows: This utility model conducts the heat of the probe to the metal block through the thermally conductive insulating sleeve, and then dissipates the heat of the metal block through water cooling. The cooling rate is greater than the heating rate of the probe, which improves the testing accuracy of the probe. The metal block of this utility model surrounds the probe to form a Faraday cage effect, shielding external electromagnetic field interference and further improving the frequency testing accuracy. Attached Figure Description
[0013] Figure 1 This is a three-dimensional structural diagram of the crystal oscillator frequency vacuum testing device according to an embodiment of the present invention.
[0014] Figure 2 This is a three-dimensional structural diagram of the crystal oscillator frequency vacuum test module according to an embodiment of this utility model.
[0015] Figure 3 This is a cross-sectional view of the crystal oscillator frequency vacuum test module according to an embodiment of the present invention.
[0016] Figure 4 This is a schematic diagram of the circulating water channel according to an embodiment of the present invention.
[0017] Explanation of icon numbers
[0018] 1. External return water pipe; 2. External inlet water pipe; 3. Sealing joint; 4. Internal return water pipe; 5. Internal inlet water pipe; 6. Vacuum chamber; 7. Probe; 8. Probe sleeve; 9. Probe welding circuit board; 10. Frequency test board; 11. Thermally conductive insulating sleeve; 12. Metal block; 13. Probe positioning block. Detailed Implementation
[0019] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of this application can be combined with each other. The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.
[0020] In this embodiment of the invention, directional indicators (such as up, down, left, right, front, back, etc.) are only used to explain the relative positional relationship and movement of the components in a specific posture (as shown in the attached figure). If the specific posture changes, the directional indicators will also change accordingly.
[0021] Furthermore, in this utility model, descriptions involving "first," "second," etc., are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features.
[0022] Please refer to Figures 2-4 The crystal oscillator frequency vacuum test module of this utility model embodiment includes a metal block, a probe welding circuit board, and several probe components.
[0023] The probe bonding circuit board is mounted on a metal block. The metal block has several holes of corresponding size to the probe assemblies, facilitating the spaced insertion of the probe assemblies. Preferably, the probe assemblies are arranged in an array. Each probe assembly includes a probe sleeve and a thermally conductive insulating sleeve fitted over the probe sleeve. The thermally conductive insulating sleeve can be made of an insulating and thermally conductive material, such as a thermally conductive silicone sleeve.
[0024] The probe sleeve has probes inserted at both ends, and the upper end of the probe sleeve is soldered to the corresponding probe welding circuit board. Preferably, the probe sleeve is perpendicular to the probe welding circuit board. The top two probes are a pair, contacting two pins of the crystal oscillator for testing. The metal block surrounds the probes, forming a Faraday cage effect that shields the signal and prevents mutual signal interference caused by the close spacing of the probes. A circulating water channel is provided inside the metal block.
[0025] The bottom of the metal block is equipped with a probe positioning block to fix the lower end of the probe sleeve and prevent the probe from swinging or shifting left and right.
[0026] In one implementation, the vibration frequency vacuum testing module also includes a frequency testing board, which is electrically connected to the probes at the lower end of the probe sleeve. The tops of the probes located at the upper end of the probe sleeve are flush with each other, and the bottoms of the probes located at the lower end of the probe sleeve are flush with each other. The probes near the probe positioning block are compressed by the frequency testing board, thereby achieving contact with the frequency testing board and establishing an electrical connection.
[0027] Please refer to Figures 1-4 The crystal oscillator frequency vacuum testing device of this utility model embodiment includes a vacuum chamber, an external return water pipe, an external inlet water pipe, an internal return water pipe, an internal inlet water pipe, and a crystal oscillator frequency vacuum testing module.
[0028] The crystal oscillator frequency vacuum testing module is located inside the vacuum chamber. The external return water pipe and external inlet water pipe are located outside the vacuum chamber. The external return water pipe and external inlet water pipe are connected to the return end and inlet end of the circulating water channel inside the metal block through the internal return water pipe and internal inlet water pipe, respectively. Preferably, sealing joints are provided on the inner and outer sides of the vacuum chamber and on the metal block. The internal return water pipe is connected to the external return water pipe and the return end of the circulating water channel, and the internal inlet water pipe is connected to the external inlet water pipe and the inlet end of the circulating water channel through sealing joints.
[0029] Cooling water enters the circulating water circuit inside the metal block through the inlet pipe and sealing joint for cooling, and then flows out through the sealing joint and return pipe. Sealing joints are installed on both the inner and outer sides of the vacuum chamber wall, and inlet and return pipes (i.e., inner return pipe, inner inlet pipe, outer return pipe, and outer inlet pipe) are distributed to connect the vacuum area and the atmospheric area.
[0030] The cooling water in this invention is supplied by a water chiller, with the temperature set to 20 degrees Celsius. It has an inlet pipe and a return pipe that pass through the vacuum chamber wall. Sealed joints connect the inlet and return pipes on both the inner and outer sides of the vacuum chamber wall. A sealed joint also connects the inlet and return pipes within the vacuum chamber to the metal block in contact with the probe. The metal block has a circulating water channel for the cooling water. The cooling rate of the water chiller is greater than the heating rate of the probe, thus improving the probe's testing accuracy. The probe sleeve is inserted into both ends of the probe and is covered by an insulating and thermally conductive material, such as thermally conductive silicone. The thermally conductive silicone is then fitted into a correspondingly sized hole in the metal block. The metal block surrounds the probe, creating a Faraday cage effect that shields against external electromagnetic interference, improving frequency testing accuracy.
[0031] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.
Claims
1. A crystal oscillator frequency vacuum testing module, characterized in that, It includes a metal block, a probe welding circuit board, and several probe assemblies. The probe welding circuit board is disposed on the metal block, and the probe assemblies are spaced apart on the metal block. Each probe assembly includes a probe sleeve and a thermally conductive insulating sleeve sleeved on the probe sleeve. Probes are inserted at both the upper and lower ends of the probe sleeve. The upper end of the probe sleeve is welded to the probe welding circuit board. A circulating water channel is provided inside the metal block.
2. The crystal oscillator frequency vacuum testing module as described in claim 1, characterized in that, The bottom of the metal block is equipped with a probe positioning block for fixing the lower end of the probe sleeve.
3. The crystal oscillator frequency vacuum testing module as described in claim 1, characterized in that, It also includes a frequency test board, which is electrically connected to the probes at the lower end of the probe sleeve.
4. The crystal oscillator frequency vacuum testing module as described in claim 1, characterized in that, The thermally conductive insulating sleeve is a thermally conductive silicone sleeve.
5. The crystal oscillator frequency vacuum testing module as described in claim 1, characterized in that, The top of the probe located at the upper end of the probe sleeve is flush with the top, and the bottom of the probe located at the lower end of the probe sleeve is flush with the bottom.
6. The crystal oscillator frequency vacuum testing module as described in claim 1, characterized in that, The probe sleeves are all perpendicular to the probe welding circuit board.
7. A crystal oscillator frequency vacuum testing device, characterized in that, It includes a vacuum chamber, an external return water pipe, an external inlet water pipe, an internal return water pipe, an internal inlet water pipe, and a crystal oscillator frequency vacuum testing module as described in any one of claims 1 to 6. The crystal oscillator frequency vacuum testing module is disposed in the vacuum chamber, and the external return water pipe and the external inlet water pipe are located outside the vacuum chamber. The external return water pipe and the external inlet water pipe are respectively connected to the return water end and the inlet water end of the circulating water channel inside the metal block through the internal return water pipe and the internal inlet water pipe.
8. The crystal oscillator frequency vacuum testing device as described in claim 7, characterized in that, Sealing joints are provided on the inner and outer sides of the vacuum chamber and on the metal block. The inner return water pipe and the outer return water pipe, the return water end of the circulating water channel, and the inner inlet water pipe and the outer inlet water pipe, the inlet water end of the circulating water channel are all connected by sealing joints.