Low-phase-noise quartz crystal oscillator

Abstract

The invention discloses a low-phase-noise quartz crystal oscillator. The oscillator comprises a phase discriminator, a loop filter and a voltage-controlled crystal oscillator, the output phase of the voltage-controlled crystal oscillator is locked through a phase discrimination loop, and low-noise and high-precision stable clock output is achieved. The detecting and packaging equipment is provided with a vibration feeding station, a material distribution testing station, a visual detecting station, a crystal transferring station and a heat sealing station on the same platform, automatic roll changing of a carrier tape is achieved through double-reel automatic winding, an upper sealing film pre-winding mechanism is arranged to avoid blocking, and automatic sealing and automatic breaking of the carrier tape are achieved by supplying sealing adhesive tape through an air injection suction cup. The actions of all the stations are coordinated and matched, the full-automatic detection and packaging process of oscillator crystals from feeding to packaging is achieved, and the efficiency is greatly improved. According to the invention, the oscillator structure is innovated, and low-phase noise and high-precision output is realized; detection packaging equipment is innovated to solve pain points in the automation process, and revolutionary upgrading of oscillator detection packaging is achieved.

Description

[0001] This application is a divisional application of Chinese patent application filed on October 11, 2023, with application number CN202311317999.8 and invention title "Low Phase Noise Quartz Crystal Oscillator and Fully Automatic Testing and Packaging Equipment Thereof". Technical Field

[0002] This invention relates to the field of quartz crystal oscillator technology, specifically to a quartz crystal oscillator that uses a crystal oscillator and a phase detection loop to achieve low phase noise, and a testing and packaging device that automates the entire process of testing and packaging of the quartz crystal oscillator. Background Technology

[0003] In industrial process control, phase noise-sensitive equipment, and systems requiring high-precision timing and synchronization, such as radar systems, GPS time synchronization, and base station timing, extremely high timing accuracy and resilience to environmental changes are essential. Therefore, crystal oscillators with extremely low phase noise are necessary. Crystal oscillators and voltage-controlled crystal oscillators can adjust their frequencies through compensation circuits and applied voltage, respectively, to adapt to environmental changes. Based on these application requirements, developing a novel quartz crystal oscillator with low phase noise can effectively address the demand for ultra-high precision and stability in this field.

[0004] On the other hand, the testing procedures for complex devices such as crystal oscillators, voltage-controlled crystal oscillators, and phase-noise quartz crystal oscillators are more complex and time-consuming than those for general crystal oscillators. Currently, mainstream testing equipment is integrated with finished product packaging, such as the multi-station integrated testing, sorting, marking, and packaging equipment for quartz crystal oscillators disclosed in authorization announcement number CN107499563 B. This equipment integrates a feeding mechanism, a main and auxiliary turntable mechanism, a material picking and sorting mechanism, a material flipping mechanism, a material marking mechanism, and a material packaging mechanism, realizing integrated operation of the testing, sorting, marking, and packaging processes for quartz crystal oscillators, significantly improving production efficiency.

[0005] However, after packaging one reel of carrier tape, this integrated equipment still requires manual reel changing before the next reel can be produced. Manual reel changing necessitates machine downtime, posing a significant risk to testing equipment with complex and precise testing procedures. First, downtime interrupts the equipment's operation, requiring some testing modules to be recalibrated upon restart, reducing testing efficiency. Second, manual operation can lead to delays in timely reel replacement after downtime, resulting in excessive downtime and increased energy consumption. Finally, relying on manual reel changing prevents continuous, unattended, 24 / 7 automated operation, limiting further capacity increases. Therefore, this manual reel changing solution has significant shortcomings in system completeness and reliability. Developing fully automated quartz crystal oscillator testing and packaging equipment with automated reel changing and loading / unloading is considered a crucial approach to achieving high-efficiency continuous production. Summary of the Invention

[0006] To address the aforementioned problems, this invention provides a fully automated quartz crystal oscillator testing and packaging device, which automates the entire process of automatic testing and packaging of quartz crystal oscillators.

[0007] The objective of this invention is achieved through the following technical solution: A fully automatic quartz crystal oscillator testing and packaging device, comprising a platform for mounting various components; an industrial control computer, a vibratory feeder, a material distribution and testing device, a CCD vision discrimination device, and a crystal transfer and orientation device fixed on the platform; a carrier tape feeding device fixed below the platform; a carrier tape guiding device fixed on the platform and laid along the carrier tape travel path; a power device for driving the carrier tape; the device further includes: A dual-reel winding device is used to automatically complete the winding and changing of carrier tape; The upper sealing film pre-winding mechanism, the sealing material feeding device, and the cutting mechanism are arranged between the dual-reel winding device and the carrier belt guiding device; The upper sealing film pre-winding mechanism is used to pre-wind the remaining upper sealing film after heat sealing; The sealing material feeding device is used to attach sealing material to the end of the upper sealing film after the upper sealing film is cut; The cutting mechanism is used to cut the carrier tape, upper sealing film, and sealing material; The coordinated operation of the dual-reel winding device, the upper sealing film pre-winding mechanism, the sealing material feeding device, and the cutting mechanism enables automatic heat sealing of the carrier tape, pre-winding of the upper sealing film, application of sealing material for sealing, and carrier tape cutting, as well as automatic reel changing, thereby achieving fully automatic continuous inspection and packaging.

[0008] Preferably, the dual-reel winding device includes: a frame for overall support; a rotatable base mounted on the frame; a reel mounting plate that abuts against or is parallel to the large surface of the rotatable base and can slide relative to the rotatable base; limiting pulleys disposed on both sides of the reel mounting plate along its length and in contact with the reel mounting plate to limit its sliding position; an elongated hole disposed in the middle of the reel mounting plate at a certain angle to the length direction of the mounting plate; and a pressure member disposed within the elongated hole, in contact with the side wall of the elongated hole, and designed with a variable diameter to change the pressure point and center distance. Beneficial effects: The sliding design of the reel mounting plate makes the reel position adjustable, facilitating the location of the reel hole when the carrier tape is broken, and improving the degree of automation.

[0009] Preferably, the upper sealing film pre-retraction mechanism includes: a vertical transmission assembly for vertical transmission; a slide that travels along the transmission path of the vertical transmission assembly; an actuator located on one side of the working surface of the slide; a push cylinder whose main body is fixed on the slide and whose free end of the piston rod is fixedly connected to the actuator; and rollers fixedly mounted on the actuator. The vertical movement of the slide and the horizontal movement of the push cylinder drive the rollers to complete the winding, unwinding, and holding of the upper sealing film. Beneficial effects: The upper sealing film pre-retraction mechanism can retract the upper sealing film in advance, avoiding obstruction of subsequent actions and ensuring smooth operation.

[0010] Preferably, the sealing material feeding device includes: a fixed base for fixing; a movable base hinged to the fixed base and capable of mounting and dismounting the tape reel; a power unit driven by the movable base; and a pushing assembly for fixing the starting end of the tape and extending the tape length forward. The pushing assembly includes: a plate fixed to the movable base; a rolling rod with one end fixed to the movable base and the other end extending in the width direction of the tape; a pushing cylinder fixed to the plate; a suction cup seat mounted on the free end of the piston rod of the pushing cylinder; and a suction cup facing the back of the tape. When the movable base moves, the suction cup uses negative pressure to hold the tape, making the adhesive side of the tape face outwards, and cooperates with the rotation of the reel to complete the adhesion of the tape to the upper sealing film. Beneficial effect: The sealing material feeding device reliably unfolds and adheres sealing tape using a negative pressure suction cup, achieving automated sealing.

[0011] Preferably, an external pressure roller is also included at the station of the dual-reel winding device to press the carrier tape firmly during the reel winding process. Beneficial effects: The external pressure roller can compact the carrier tape, reduce springback, and improve winding quality.

[0012] Preferably, a tensioning mechanism and a pressure roller are also included, located between the power unit and the dual-reel winding device, for temporary clamping or tensioning during carrier belt conveying. Benefits: The tensioning mechanism and pressure roller allow for fixing or applying tension to the carrier belt when needed, facilitating reel changes.

[0013] Preferably, the rotating base of the dual-reel winding device is driven by a first motor, the pressing component by a second motor, and the two reels by a third and a fourth motor, respectively. The slide of the upper sealing film pre-winding mechanism is driven by a first motor, and the push cylinder by a second motor. The movable seat of the sealing material feeding device is driven by a first motor, and the push cylinder by a second motor. Beneficial effect: The motor drives of each actuator are more flexible and controllable.

[0014] Preferably, the roller is made of a non-stick material. Benefits: The non-stick material prevents the tape from sticking and affecting material feeding.

[0015] To address the above-mentioned problems, this invention also provides a low-phase-noise quartz crystal oscillator, comprising: A crystal oscillator is used to provide a high-precision and low-noise reference clock signal. A phase detector, whose first input terminal is connected to the output terminal of the crystal oscillator, is used to detect phase changes of the input signal; A loop filter, connected to the output of the phase detector, is used to provide a certain loop bandwidth; A voltage-controlled crystal oscillator, whose input is connected to the output of the loop filter, is used to adjust the frequency and phase of the output signal according to the detection result of the phase detector. The second input terminal of the phase detector is connected to the output terminal of the voltage-controlled crystal oscillator and compares the phase relationship between the two input terminals. Its output control signal is modulated by the loop filter to make the frequency and phase of the output signal lock on the phase of the crystal oscillator, thereby obtaining a clock signal output with high frequency accuracy, low phase noise and high stability.

[0016] In summary, the present invention has the following advantages compared with the prior art: 1. It realizes fully automated and continuous operation of quartz crystal oscillator testing and packaging, greatly improving efficiency.

[0017] 2. The dual-reel automatic reel changing design solves the inefficiency problem of traditional manual reel changing, eliminating the need for manual intervention and automating the entire inspection and packaging process.

[0018] 3. The reel sliding design allows the broken part of the carrier tape to automatically find the empty reel hole during the reel change process, ensuring smooth docking and preventing carrier tape breakage or process interruption.

[0019] 4. The upper sealing film pre-collection mechanism avoids obstructing subsequent processes, and the sealing tape feeding device realizes automatic tape application and sealing. The coordinated actions of the mechanisms ensure smooth process operation.

[0020] 5. Various auxiliary designs, such as external pressure rollers, tensioning mechanisms, non-stick rollers, and air suction cups, improve the reliability of automatic operation and product quality.

[0021] 6. The use of motor drive and control makes the operation of each actuator more flexible and controllable, and can adapt to different process schemes.

[0022] 7. This equipment has enabled the automated upgrade of quartz crystal oscillator testing and packaging, which not only improves efficiency but also reduces production costs, and is of great significance for increasing production capacity.

[0023] 8. A low-phase-noise, high-stability oscillator with phase detection loop-locked voltage-controlled crystal output can provide a higher-precision clock reference signal.

[0024] 9. This patent incorporates innovations in multiple aspects, including mechanical structure, control method, and device application. The overall effect is to achieve a revolutionary upgrade in the automatic testing and packaging process of quartz crystal oscillators, as well as an improvement in related product indicators.

[0025] 10. This solution can be extended to more crystal resonator testing and packaging scenarios, expanding product types and helping companies expand the production capacity of quartz crystal oscillators. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of a finished crystal oscillator reel (the adhesive seal is open). Figure 2 This is a schematic diagram of the packaging equipment. Figure 3 This is a structural schematic diagram of the packaging device from another angle and at a partial location. Figure 4 This is a structural schematic diagram of the packaging device from another angle and at a partial location. Figure 5 This is a structural schematic diagram of the packaging equipment from another angle; Figure 6 This is a schematic diagram of the upper sealing film pre-shrinking mechanism; Figure 7 This is a structural schematic diagram of the packaging device from another angle and at a partial location. Figure 8 for Figure 7 A magnified view of a portion of point a; Figure 9 This is the front view of the packaging device.

[0027] The diagram shows the following components: Platform 1, Frame 11, Carrier Belt Feeding Device 2, Carrier Belt Guiding Device 3, Upper Sealing Film Feeding Device 4, Carrier Belt Heat Sealing Mechanism 5, Power Unit for Driving Carrier Belt 6, Reel 01, Carrier Belt 02, Upper Sealing Film 03, Sealing Material 04, Tape Reel 05, Double Reel Winding Device 70, Upper Sealing Film Pre-winding Mechanism 80, Sealing Material Feeding Device 90, Cutting Mechanism 100, Frame 71, Rotary Seat 72, Reel Mounting Plate 73, Limiting Pulley 731, Elongated Hole 732, Pressing Component 733, First Motor 734, Second Motor 735, Third Motor 736, Third Motor 737, Transmission Assembly 81, Slide 82, Actuating Base 83. Push cylinder 84, roller 85, fixed seat 91, movable seat 92, pushing assembly 93, plate 931, rolling rod 932, pushing cylinder 933, suction cup seat 934, suction cup 935, stop bar 936, outer pressure roller 200, tensioning mechanism 300, pressing roller 400, guide groove plate 500. Detailed Implementation

[0028] The following is a description of an example of a preferred embodiment of the present invention. Please note that the following embodiments are for illustrative purposes only, and the present invention is not limited to the following embodiments.

[0029] Furthermore, in the accompanying drawings referenced in the embodiments, components with the same function will be referred to using the same reference numerals. Also, the drawings are for illustrative purposes only, and therefore the scale of the objects depicted may differ from the scale of actual objects. The scale of different objects in the drawings may also differ. Specific object scales should be determined based on the following description. Positional movement along the X, Y, and Z axes mentioned in the embodiments can be achieved by using a cross carriage or robotic arm, unless otherwise specified.

[0030] Example 1 Refer to all attached diagrams I. This technical solution proposes a low-phase-noise quartz crystal oscillator for achieving high-precision and high-stability clock signal output. It consists of four key components: a crystal oscillator, a phase detector, a filter, and a voltage-controlled crystal oscillator.

[0031] The crystal oscillator selected is the Abracon ABT-134-20.000MHz. One end of R7 is connected to the regulated power supply, and the other end is grounded through the stabilizing capacitor C16. The fifth and tenth pins of the crystal oscillator are directly grounded, and the sixth pin is connected to the phase detector through the coupling capacitor C8, providing the phase detector with a precise phase comparison reference. This crystal oscillator adopts an optimized crystal cut direction design, which greatly improves the frequency maintenance accuracy.

[0032] The phase detector employs advanced automatic frequency control technology to detect minute phase changes in the input signal. The output of the crystal oscillator is used as the reference phase signal input to the REFin terminal, and the output of the voltage-controlled crystal oscillator is used as the phase signal to be measured input to the RFINA terminal. Through an internal digital phase detection circuit, the phase relationship between the two signals is compared in real time, and a corresponding control voltage representing the phase difference is output according to a pre-defined algorithm. The phase detector also integrates a programmable loop bandwidth setting function, facilitating the optimization of loop filtering parameters.

[0033] The loop filter employs a simple RC filter circuit, consisting of resistor R1 and capacitors C9 and C10, providing a loop bandwidth of approximately 1kHz. This effectively suppresses noise interference and improves the stability of loop control. The filter is compact, cost-effective, and easy to debug. Higher-order or adaptive digital filtering schemes can also be selected as needed.

[0034] The voltage-controlled crystal oscillator (VCO) uses the small-sized, low-phase-noise ASPF7L MEMS VCO, manufactured using silicon micromechanical systems (MEMS) technology. The mechanical vibration frequency of the crystal is modulated by applying a control voltage, thus modulating the output frequency. This VCO exhibits superior phase noise compared to ordinary crystal resonators, meeting the requirements of high-precision phase-locked loops (PLLs). Its control terminal, Vtune, modulates the output frequency through the output voltage of the loop filter, locking the output frequency to the crystal phase, thereby achieving a low-noise, stable, and high-precision clock output.

[0035] This technical solution eliminates the need for a large temperature control system, resulting in lower costs and a phase noise level of less than -20dBc / Hz@10kHz. The entire circuit design utilizes surface mount technology (SMT), with component heights not exceeding 6mm, making it ideal for miniaturized electronic products. Further optimization can be achieved by selecting a digital signal processor and temperature sensor to implement digital intelligent temperature control, further improving frequency accuracy and temperature adaptability, thus providing a reliable, cost-effective solution for high-end clock sources.

[0036] The design can also be expanded and optimized: 1. Higher frequency crystal oscillators, such as 50MHz or 100MHz, can be selected to expand the frequency selection range.

[0037] 2. Optimize phase detector parameters, customize loop bandwidth, gain, etc., to improve control flexibility.

[0038] 3. Upgraded to a wide temperature compensation scheme, combined with CNC constant temperature control, to expand the operating temperature range.

[0039] 4. Add a self-verification and calibration module to correct control deviations in real time and improve long-term frequency stability.

[0040] 5. Employing a low-noise amplifier reduces phase noise and meets higher precision requirements.

[0041] 6. Integrated design with digital signal processors enables intelligent digital control and optimizes cost-effectiveness.

[0042] 7. Using a dedicated ASIC chip instead of a standard phase detector allows for customization of key parameters and improved performance.

[0043] 8. MEMS technology and CMOS integration manufacturing enable smaller sizes and mass production.

[0044] 9. System-level packaging and testing can improve product reliability and consistency.

[0045] 10. Output frequency and performance indicators can be customized for different applications to meet different needs.

[0046] II. This technical solution also proposes a fully automated quartz crystal oscillator testing and packaging device, referring to... Figure 2 For ease of explanation and understanding, the coordinate system is defined as follows: the Z-axis represents the direction of gravity, and the X-axis and Y-axis define two directions on the horizontal plane; the three axes are orthogonal. In the following explanation, the direction parallel to the Y-axis will also be referred to as the "depth direction Y," and the direction parallel to the Z-axis will be referred to as the "vertical direction Z."

[0047] The device includes: 1) Platform 1 for component installation; 2) The frame 11 supporting platform 1; 3) The industrial control computer, vibratory feeder, material distribution and testing device, CCD vision discrimination device, crystal transfer and orientation device, and other detection and processing units fixed on platform 1 are not directly related to this improvement and will not be described in detail here; 4) A carrier belt feeding device 2 fixed below platform 1; 5) A carrier belt guide device 3 fixed on platform 1 and laid along the carrier belt travel route; 6) The upper sealing film feeding device 4 and the carrier belt heat sealing mechanism 5 are mounted above the carrier belt guide device 3; 7) Power unit 6 for driving the carrier belt; 8) A carrier tape winding device arranged in a straight line with the carrier tape guide device 3 for winding the carrier tape, not shown in the figure.

[0048] The feeding of the upper sealing film feeding device 4 is synchronized with the movement of the carrier belt after heat sealing; the speed of the power unit 6 matches the speed of the material distribution test device.

[0049] Key structural improvements were focused on the carrier belt conveying and winding mechanisms. Figure 1 The image shows a completed carrier tape reel, including carrier tape reel 01, carrier tape 02, top sealing film 03, and sealing material 04. The sealing material can be either paper tape or masking tape. For ease of observation, the tape is not attached. In actual operation, after winding to the set count, a blank space of approximately 30-40cm is left on the carrier tape, and an additional 60-100cm of top sealing film is left to wrap around the reel 1.5 times. Finally, the sealing material is applied. A typical reel of this type of packaged product contains 1000-3000 pieces. Taking a commonly used 2000-piece count for ordinary surface mount crystal oscillators as an example, one reel is usually completed in 30 minutes. However, once the reel is full, manual reel changing is required, which is not only time-consuming but also prone to human error.

[0050] Based on this, the improvements are as follows: - The original carrier tape winding device was replaced with a double reel winding device 70 to achieve automatic roll changing, and a sealing film pre-winding mechanism 80, a sealing material feeding device 90 and a cutting mechanism 100 were set between the winding device and the guiding device.

[0051] - The upper sealing film pre-shrinking mechanism 80 allows the lifting position of its execution part to be set arbitrarily within the reachable range.

[0052] - The cut-off mechanism 100 allows its execution part to reach any desired position on the X-axis, Y-axis, and Z-axis.

[0053] - The sealing material feeding device 90 can make its actuator drag the sealing material to contact and adhere to the upper sealing film.

[0054] These newly added devices and mechanisms work in conjunction with existing conveying power devices, heat sealing mechanisms, and other modules to achieve fully automated packaging and winding.

[0055] For the specific structure of the dual-reel winding device 70, refer to Figure 5 ,include: 1) Frame 71, used to provide overall support for the device; 2) A rotatable mount 72, which is rotatably mounted on the frame 71; 3) Reel mounting plate 73, which is abutted or parallel to the large surface of the rotator and can slide relative to the rotator. Its length dimension is designed to accommodate two reels, with the center of one side of the plate surface of the two reels located in the same plane. This plane is also on the same horizontal plane as the centerline of the carrier tape width direction. 4) Multiple limiting pulleys 731 are arranged on both sides of the reel mounting plate along its length and contact the reel mounting plate to limit their sliding position; 5) The elongated hole 732 is located in the middle of the reel mounting plate, and its direction is at a certain angle to the length direction of the mounting plate; 6) The pressure member 733 is located inside the elongated hole and contacts the side wall of the elongated hole. It is a variable diameter design to change the pressure point and center distance, so the overall position of the reel mounting plate can be adjusted when it rotates in different positions.

[0056] The power unit preferably includes a motor drive, comprising a first motor 734 for driving the rotary table 72 to rotate, a second motor 735 for driving the pressure member 733 to rotate, and a third motor 736 and a third motor 737 for driving one of the reels to wind up; the transmission and control methods of these motors are not limited.

[0057] The sliding design of the reel mounting plate 73 takes into account two aspects: Firstly, during step seven when applying the tape, the sliding belt changes the distance and angle between itself and the tape feeding device, allowing for more flexible coordination to achieve reliable adhesion. Secondly, during the carrier belt docking in step eight, the sliding mechanism, the rotation of the rotary table 72, and the reel work together to ensure that the carrier belt returns to the hole position after it has mistakenly passed it, thus achieving correct docking.

[0058] Reference Figure 6 The specific structure of the upper sealing film pre-receiving mechanism 80 includes: 1) A vertically mounted transmission assembly 81, which is fixed to the frame 71; 2) The slide 82 travels along the transmission path of the transmission assembly 81; 3) The actuator 83 is located on one side of the working surface of the slide 82; 4) The push cylinder 84, the main body of which is fixed on the slide block 82, and the free end of the piston rod is fixedly connected to the actuator base 83; 5) Roller 85, fixedly mounted on the actuator base 83; 6) The direction of motion of the push cylinder 84 is along the depth direction of the actuator 83.

[0059] The power source for the slide 82 is not shown in the figure. It moves the slide 82 in the height direction to adjust the alignment of the roller 85 with the upper sealing film in the height direction. The push cylinder 84 moves the roller 85 in the depth direction to adjust its positional alignment with the upper sealing film. With the coordinated operation of these two power sources, the pre-tensioning and release of the upper sealing film are completed, thereby ensuring continuous operation of the equipment.

[0060] Reference Figure 5 The specific structure of the sealing material feeding device 90 includes: 1) Fixing base 91, fixed on frame 71; 2) The movable seat 92 is hinged to the fixed seat 91 and can be detachably connected to the tape reel 05. During the rotation of the movable seat 92, the position of the tape reel 05 is higher than the position when the carrier tape is normally wound. 3) The power unit (not shown in the figure) is connected to the movable seat 92 via a transmission. 4) Pushing component 93, used to fix the starting end of the tape and extend forward to unfold the tape length. Pushing component 93 (refer to...) Figure 7-8 )include: ① The plate 931 is fixed at one end to the movable seat 92, and the other end extends in the direction of the tape width; ② The roller 932 is fixed at one end to the movable seat 92, and the other end extends in the direction of the tape width and exceeds the tape width. It is made of non-stick material. ③ Push cylinder 933 is fixed on plate 931; ④ Suction cup seat 934, installed at the free end of the piston rod of the push cylinder; ⑤ At least one suction cup 935, with the suction nozzle facing downwards toward the back of the tape; 5) The baffle 936 is set on the rolling rod, made of non-stick material, and has a nozzle inside, which can blow the tape to the suction cup for pickup.

[0061] When using new tape for the first time, you need to manually pull out the starting end of the tape, so that it goes around the roller and reaches below the suction cup (e.g. Figure 8 (As shown). During operation, the suction cup uses negative pressure to hold the tape, ensuring the adhesive side faces outwards, facilitating bonding between the movable seat and the upper sealing tape as it moves. The purpose of the push cylinder is to more flexibly push and bond the tape.

[0062] To facilitate the suction cup's adhesion of the tape, a baffle 936 with a nozzle is installed on the adhesive side of the tape. This baffle is made of a non-stick material and is mounted on the roller rod, with the nozzle's air passage located inside the baffle. After each application, the tape falls onto the baffle, bringing the suction cup closer to the tape and improving adhesion. Simultaneously, the airflow from the nozzle blows the tape towards the suction cup, further increasing the success rate of adhesion.

[0063] An outer pressure roller 200 is provided at the winding station of the reel. During winding, the outer pressure roller 200 is held at the outermost circumference of the carrier tape by power. The power can be obtained by setting springs or cylinders or other methods, which are not shown in the figure. The purpose of this setting is to prevent the carrier tape from springing back during winding. At the same time, it is also used to press the adhesive position firmly after the tape is applied.

[0064] A tensioning mechanism 300 is provided between the power unit 6 that drives the carrier belt and the dual-reel winding device 70. Below the tensioning mechanism 300 is a pressure roller 400 that can be moved away from or closer to the carrier belt. The power source of the pressure roller can be a cylinder, not shown in the figure. The pressure roller is used for temporary fixation or to increase friction by clamping. For example, in step four of the equipment's workflow, the carrier belt is fixed so as to separate it from the upper sealing film. Or, for example, in step seven, the upper sealing film is kept under tension after being cut, which helps with winding and tape adhesion.

[0065] Reference Figure 9 To make it easier for the cut-off carrier tape to enter the newly replaced empty reel hole, a guide groove plate 500 is fixed on the side of the frame 71.

[0066] Specific workflow: Step 1: The qualified crystals that have passed the test are placed into the carrier tape by the crystal transfer and orientation device; Step 2: The power unit 6 driving the carrier tape, one of the reels of the dual-reel winding device 70, and the carrier tape heat sealing mechanism 5 operate synchronously, simultaneously conveying, heat-sealing, and winding the carrier tape containing the crystal; Step 3: After the set quantity of heat-pressed packaging is reached, leave an empty space of about 30 cm for the carrier tape. When this empty space of carrier tape is transferred between the reel and the carrier tape guide device 3, the reel stops moving. Step 4: The power unit 6 driving the carrier belt continues to transmit power (therefore, the carrier belt will exhibit...). Figure 3As shown, the upper sealing film is separated from the lower sealing film, and the space between the two provides space for the upper sealing film pre-shrinking mechanism 80 to enter. Step 5: The actuator of the upper sealing film pre-retraction mechanism 80 quickly lifts the upper sealing film upwards to pre-retract a length sufficient to wrap around the carrier tape reel 1.5 times. The lifted state is as follows. Figure 2 As shown; Step 6: The cutting mechanism 100 cuts the carrier tape, the reel quickly winds up, the upper sealing film pre-winding mechanism 80 decreases in speed in coordination with the reel winding until all the pre-wound upper sealing film is wound up, the upper sealing film pre-winding mechanism 80 moves away from the upper sealing film, and the cutting mechanism 100 cuts the upper sealing film. Step 7: The actuating part of the sealing material feeding device 90 adheres the sealing material to the cut end of the upper sealing film. The sealing material feeding device 90 unfolds a certain length of tape by swinging, and the reel continues to rewind until the tape and the upper sealing film are pasted to the required length to meet the sealing requirements. At the same time, the truncated carrier tape gradually lengthens during transmission; Step 8: The cutting mechanism 100 cuts the sealing material, and the execution part of the sealing material feeding device 90 is reset; the double reel winding device 70 rotates as a whole, and the sealed reel moves away from the winding position so that it can be replaced with a new empty reel by means of other means such as a robotic arm with a suction cup, while the other empty reel approaches the end of the cut carrier tape (all known reels have at least one hole for receiving the end of the carrier tape). By setting a sensor and cooperating with the rotation of the reel, the end of the carrier tape enters the hole, and the reel is started to rotate to start a new winding operation. The double reel winding device 70 rotates as a whole so that the reel that entered the winding operation comes to the normal winding position.

[0067] This dual-reel design solves the problem of traditional single-reel designs requiring machine downtime for reel replacement, and achieves automated packaging and rewinding processes, significantly improving automation levels and work efficiency, enabling true continuous production.

Claims

1. A low-phase-noise quartz crystal oscillator that has undergone fully automated testing and packaging, characterized in that, include: Crystal oscillators are used to provide a high-precision and low-noise reference clock signal; A phase detector, whose first input terminal is connected to the output terminal of the crystal oscillator, is used to detect phase changes of the input signal; A loop filter, connected to the output of the phase detector, is used to provide a certain loop bandwidth; A voltage-controlled crystal oscillator, whose input terminal is connected to the output terminal of the loop filter, is used to adjust the frequency and phase of the output signal according to the detection result of the phase detector; The second input terminal of the phase detector is connected to the output terminal of the voltage-controlled crystal oscillator and compares the phase relationship between the two input terminals. Its output control signal is modulated by the loop filter to make the frequency and phase of the output signal lock on the phase of the crystal oscillator, thereby obtaining a clock signal output with high frequency accuracy, low phase noise and high stability. The low-phase-noise quartz crystal oscillator is tested and packaged using a fully automated quartz crystal oscillator testing and packaging equipment. This equipment includes: a platform for mounting the various components; an industrial control computer, a vibratory feeder, a material distribution and testing device, a CCD vision discrimination device, and a crystal transfer and orientation device fixed on the platform; a carrier tape feeding device fixed below the platform; a carrier tape guiding device fixed on the platform and laid along the carrier tape's travel path; and a power device for driving the carrier tape. A dual-reel winding device is used to automatically complete the winding and changing of carrier tape; The upper sealing film pre-winding mechanism, the sealing material feeding device, and the cutting mechanism are arranged between the dual-reel winding device and the carrier belt guiding device. The upper sealing film pre-winding mechanism is used to pre-wind the remaining upper sealing film after heat sealing is completed; The sealing material feeding device is used to attach sealing material to the end of the upper sealing film after the upper sealing film is cut; The cutting mechanism is used to cut the carrier tape, the upper sealing film, and the sealing material; The coordinated operation of the dual-reel winding device, the upper sealing film pre-winding mechanism, the sealing material feeding device, and the cutting mechanism enables automatic heat sealing of the carrier tape, pre-winding of the upper sealing film, application of sealing material for sealing, and carrier tape cutting, as well as automatic reel changing, thereby achieving fully automatic continuous inspection and packaging. The dual-reel winding device includes: a frame for overall support; a rotatable base mounted on the frame; a reel mounting plate that is abutting or parallel to the large surface of the rotatable base and can slide relative to the rotatable base; limiting pulleys disposed on both sides of the reel mounting plate along its length and in contact with the reel mounting plate to limit its sliding position; an elongated hole disposed in the middle of the reel mounting plate at a certain angle to the length direction of the mounting plate; and a pressure member disposed in the elongated hole, in contact with the side wall of the elongated hole, and designed with a variable diameter to change the pressure point and center distance.

2. The low phase noise quartz crystal oscillator according to claim 1, characterized in that... The upper sealing film pre-receiving mechanism includes: a vertical transmission assembly for vertical transmission; a slide that travels along the transmission path of the vertical transmission assembly; an execution base located on one side of the working surface of the slide; a push cylinder whose main body is fixed on the slide and whose free end of the piston rod is fixedly connected to the execution base; and rollers fixedly installed on the execution base; the slide moves in the vertical direction and the push cylinder moves in the horizontal direction, driving the rollers to complete the winding, unwinding and holding of the upper sealing film.

3. The low phase noise quartz crystal oscillator according to claim 1, characterized in that... The sealing material feeding device includes: a fixed base for fixing; a movable base hinged to the fixed base and capable of detaching the tape reel; a power unit connected to the movable base in a transmission manner; and a pushing assembly for fixing the starting end of the tape and extending the tape length forward. The pushing assembly includes: a plate fixed on the movable base; a rolling rod with one end fixed to the movable base and the other end extending in the width direction of the tape; a pushing cylinder fixed on the plate; a suction cup seat installed at the free end of the piston rod of the pushing cylinder; and a suction cup facing the back of the tape. When the movable base moves, the suction cup uses negative pressure to hold the tape, so that the adhesive side of the tape faces outward, and the tape is bonded to the upper sealing film in conjunction with the rotation of the reel.

4. The low phase noise quartz crystal oscillator according to claim 1, characterized in that... It also includes an external pressure roller installed at the station of the dual-reel winding device, used to press the carrier tape during the reel winding process.

5. The low phase noise quartz crystal oscillator according to claim 1, characterized in that... It also includes a tensioning mechanism and a pressure roller disposed between the power unit and the dual-reel winding device, for temporary clamping or tensioning during the conveyor belt transport process.

6. The low phase noise quartz crystal oscillator according to claim 1, characterized in that... The rotating base of the dual-reel winding device is driven by a first motor, the pressing member is driven by a second motor, and the two reels are driven by a third and a fourth motor, respectively.

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