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CN-122017412-A - Clock wafer vacuum measurement system and test method thereof

CN122017412ACN 122017412 ACN122017412 ACN 122017412ACN-122017412-A

Abstract

The embodiment of the invention discloses a clock wafer vacuum measurement system and a test method thereof, wherein the system comprises a water-cooling radiator, a vacuum cavity, a probe module and a measurement device, wherein the probe module and the measurement device are arranged in the vacuum cavity, the system also comprises a TEC module and a heat conducting piece, the water-cooling radiator is in heat conduction connection with the hot end of the TEC module, the heat conducting piece is in heat conduction connection with the probe module and the cold end of the TEC module, and the probe module conducts heat to the cold end of the TEC module through the heat conducting piece. The invention realizes the accurate measurement of the frequency and the impedance of the 32.768KHz clock wafer in the high vacuum environment, and has the function of in-situ trimming.

Inventors

  • Zhou Danxing

Assignees

  • 深圳市鑫亿晶科技有限公司

Dates

Publication Date
20260512
Application Date
20260205

Claims (10)

  1. 1. The utility model provides a clock wafer vacuum measurement system, includes water-cooling radiator, vacuum cavity and locates probe module, the measuring device in the vacuum cavity, its characterized in that still includes TEC module and heat conduction spare, and water-cooling radiator is connected with the hot junction conduction of TEC module, and the heat conduction spare is connected with the cold junction conduction of probe module and TEC module, and probe module passes through the heat conduction spare with heat conduction to the cold junction of TEC module.
  2. 2. The clock wafer vacuum measurement system of claim 1, wherein the water-cooled heat sink is disposed on a wall of the vacuum chamber and the TEC module is disposed inside the water-cooled heat sink.
  3. 3. The clock wafer vacuum measurement system of claim 2, wherein the cold water outlet and the cold water inlet of the water cooled heat sink are both outside the vacuum chamber.
  4. 4. The clock wafer vacuum measurement system of claim 1, wherein the vacuum chamber outer wall encloses a water-cooled jacket.
  5. 5. The clock wafer vacuum measurement system of claim 1, wherein the thermally conductive member is formed by stacking a plurality of red copper flakes.
  6. 6. The clock wafer vacuum measurement system of claim 1, wherein the probe module comprises a probe and a probe mount, and the probe mount is provided with a temperature sensor.
  7. 7. The clock wafer vacuum measurement system of claim 1, wherein a Z-axis assembly is disposed in the vacuum chamber, a probe mount is disposed on the Z-axis assembly, and the probe module is disposed on the probe mount.
  8. 8. The clock wafer vacuum measurement system of claim 1, further comprising a laser assembly for trimming the crystal oscillator in the vacuum cavity, wherein the vacuum cavity is correspondingly provided with a glass window, and the probe module is externally connected with a frequency testing device for detecting the frequency of the crystal oscillator through a coaxial line.
  9. 9. The clock wafer vacuum measurement system of claim 8, wherein the system trims the crystal oscillator according to the steps of: Detecting the current resonant frequency F real and the impedance R esr of the crystal oscillator; If the |F real −F target ∣>δ,F target is the target resonant frequency and delta is the preset threshold value, controlling the laser component to emit single pulse to remove the electrode material on the crystal oscillator by single laser; And measuring the crystal oscillator frequency again, if the frequency of the crystal oscillator is not more than delta, finishing the trimming of the crystal oscillator, and if the frequency of the crystal oscillator is not more than delta, continuing to perform single laser removal until the frequency of the crystal oscillator is not more than delta, and repeating the steps until the frequency of the crystal oscillator is not more than delta.
  10. 10. A method of testing a clock wafer vacuum measurement system as claimed in any one of claims 1 to 9, wherein the power P of the TEC module is adjusted in dependence on the real time temperature of the probe module: P=K p e+K i ∫edt+K d dt/de; e=t A - T target , wherein e is the temperature difference between the real-time temperature of the probe module and the target temperature, T target is the target temperature, T A is the real-time temperature of the probe module, dt represents an integral variable, dt/de represents the derivative of the temperature difference with respect to time, and K p 、K i 、K d is a proportional, integral and derivative control parameter respectively.

Description

Clock wafer vacuum measurement system and test method thereof Technical Field The invention relates to the technical field of crystal oscillators, in particular to a clock wafer vacuum measurement system and a test method thereof. Background Currently, parameter tests (such as equivalent series resistance ESR and resonance frequency Fr) of a 32.768KHz crystal oscillator under a vacuum environment mainly depend on vector network analyzers or impedance analyzers of companies such as Germany, agilent and the like in the United states. Such devices are expensive (typically 50-100 RMB) and core technology is subject to export regulations, presenting a neck risk, after-market maintenance and calibration difficulties. Conventional crystal oscillator testing is performed at standard atmospheric pressure. However, the inside of the 3215 crystal oscillator is in a high vacuum state after sealing welding, and the Q value is increased and the frequency is shifted due to the disappearance of air damping. Test data under normal pressure cannot truly reflect the performance of the crystal oscillator in a final working environment, so that the frequency after sealing welding exceeds the standard, and the yield is low. In a high vacuum environment, the convection of the gas disappears, and the heat cannot be dissipated through the air. Joule heat generated when the test probes of the probe module are in contact with the crystal oscillator or the circuit is in operation can accumulate in the cavity, resulting in a local temperature rise. Since the crystal oscillator frequency is temperature sensitive, the temperature rise can lead to severe frequency drift (thermal drift). Existing vacuum test equipment mostly lacks an active cooling mechanism for a tiny test area. Disclosure of Invention The technical problem to be solved by the embodiment of the invention is to provide a clock wafer vacuum measurement system and a test method thereof, so as to realize active cooling of a probe module and solve the problem of thermal drift in a vacuum environment. In order to solve the technical problems, the embodiment of the invention provides a clock wafer vacuum measurement system which comprises a water-cooling radiator, a vacuum cavity, a probe module arranged in the vacuum cavity, a measurement device, a TEC module and a heat conducting piece, wherein the water-cooling radiator is in heat conduction connection with the hot end of the TEC module, the heat conducting piece is in heat conduction connection with the probe module and the cold end of the TEC module, and the probe module conducts heat to the cold end of the TEC module through the heat conducting piece. Further, the water-cooling radiator is arranged on the wall of the vacuum cavity, and the TEC module is arranged on the inner side of the water-cooling radiator. Further, both the cold water outlet and the cold water inlet of the water-cooled radiator are outside the vacuum cavity. Further, the outer wall of the vacuum cavity is wrapped with a water-cooling jacket. Further, the heat conducting piece is formed by overlapping a plurality of red copper sheets. Further, the probe module consists of a probe and a probe seat, and a temperature sensor is arranged on the probe seat. Further, a Z-axis assembly is arranged in the vacuum cavity, a probe seat fixing block is arranged on the Z-axis assembly, and the probe module is arranged on the probe seat fixing block. Further, the device also comprises a laser component for trimming the crystal oscillator in the vacuum cavity, a glass window is correspondingly arranged on the vacuum cavity, and the probe module is externally connected with a frequency testing device for detecting the frequency of the crystal oscillator through a coaxial line. Further, the system modifies the crystal oscillator according to the following steps: Detecting the current resonant frequency F real and the impedance R esr of the crystal oscillator; If the |F real−Ftarget∣>δ,Ftarget is the target resonant frequency and delta is the preset threshold value, controlling the laser component to emit single pulse to remove the electrode material on the crystal oscillator by single laser; And measuring the crystal oscillator frequency again, if the frequency of the crystal oscillator is not more than delta, finishing the trimming of the crystal oscillator, and if the frequency of the crystal oscillator is not more than delta, continuing to perform single laser removal until the frequency of the crystal oscillator is not more than delta, and repeating the steps until the frequency of the crystal oscillator is not more than delta. Correspondingly, the embodiment of the invention also provides a test method of the clock wafer vacuum measurement system, which adjusts the power P of the TEC module according to the real-time temperature of the probe module: P=Kpe+Ki∫edt+Kddt/de; e=TA- Ttarget; Wherein e is the temperature difference between the real-time temperature of the