Temperature characteristic testing device and testing method for surface mount filter

Abstract

The invention provides a surface mount filter temperature characteristic testing device, which belongs to the technical field of electronic component testing and comprises an in-box testing unit and a main control and data acquisition system. The in-box test unit comprises a multi-station test fixture system, a high and low temperature control system and an automatic switch switching system; the multi-station test fixture system comprises a PCB circular plate; the automatic switch switching system comprises a signal input interface, a signal output interface, an upper layer radio frequency switch and a lower layer radio frequency switch. And the master control and data acquisition system is in communication connection with the high and low temperature control system. According to the integrated PCB test module, the multiple radio frequency switches and the transmission lines with the same length, the uncertainty and loss of radio frequency paths are reduced to the maximum extent, and the consistency and accuracy of test data are ensured. The invention further discloses a testing method of the surface mount filter temperature characteristic testing device.

Description

Technical Field

[0001] This invention relates to the field of electronic component testing technology, and more specifically, to a surface mount filter temperature characteristic testing device. The invention also relates to a testing method for this surface mount filter temperature characteristic testing device. Background Technology

[0002] Surface mount filters are key components in modern communication equipment, consumer electronics and other fields. Their performance parameters (such as center frequency, passband width, insertion loss, in-band ripple, etc.) will change with the ambient temperature. Therefore, it is essential to conduct accurate and efficient testing of their temperature characteristics during production, inspection, reliability assessment and product development.

[0003] Currently, the common testing method involves placing the filter and test fixture together in a temperature chamber, and then connecting it to an external vector network analyzer (VNA) via a coaxial cable passing through the chamber wall for measurement. This method has the following drawbacks:

[0004] 1) Extremely low efficiency: Traditional testing methods can only test one or a small number of samples at a time, making it impossible to conduct rapid batch testing, which is time-consuming and energy-intensive.

[0005] 2) Poor temperature stability: Frequent opening and closing of the door causes drastic fluctuations in the temperature field inside the chamber, requiring a long period of stabilization before testing can begin, further reducing efficiency.

[0006] 3) Unreliable connection: Long cables inside and outside the chamber can introduce significant insertion loss and phase error. Frequent opening and closing of the chamber door can also cause loosening of the circuit connectors and poor contact between the sample and the test fixture, affecting the test accuracy.

[0007] 4) Poor consistency: The degree of cable bending and the position of the clamp may be different in each test, which introduces additional measurement errors.

[0008] 5) Low level of automation: The entire testing process requires manual intervention, and it is impossible to achieve fully automated temperature cycling and data acquisition. The labor cost is high and errors are easy to occur.

[0009] Therefore, there is an urgent need for a testing device and method for the temperature characteristics of surface-mount filters that can achieve high precision, high efficiency, and high reliability. Summary of the Invention

[0010] The primary objective of this invention is to overcome the shortcomings of the aforementioned background technology and to provide a surface mount filter temperature characteristic testing device.

[0011] The second objective of this invention is to provide a test method for such a surface mount filter temperature characteristic test device.

[0012] To achieve the aforementioned first objective, the technical solution of the present invention is: a surface mount filter temperature characteristic testing device, characterized in that: it includes an in-chamber testing unit and a main control and data acquisition system; the in-chamber testing unit includes a multi-station testing fixture system, a high and low temperature control system, and an automatic switch switching system;

[0013] The multi-station test fixture system is located within the high and low temperature control system. The multi-station test fixture system includes a circular PCB board; multiple test stations are integrated along the circumference of the upper layer of the circular PCB board.

[0014] The automatic switch switching system includes a signal input interface, a signal output interface, an upper-layer RF switch, and a lower-layer RF switch. Both the signal input and output interfaces are located on the side of a circular PCB board. The upper-layer RF switch is located at the center of the upper layer of the circular PCB board, and the input pin of each test station is connected to the upper-layer RF switch via a high-frequency microstrip line. The lower-layer RF switch is located at the center of the lower layer of the circular PCB board, and the output pin of each test station is connected to the lower-layer RF switch via a high-frequency microstrip line. The signal input interface is connected to the common port of the upper-layer RF switch via a high-frequency microstrip line and is connected to the main control and data acquisition system via a high-frequency connecting line passing through the high and low temperature control system. The signal output interface is connected to the common port of the lower-layer RF switch and is connected to the main control and data acquisition system via a high-frequency connecting line passing through the high and low temperature control system.

[0015] The main control and data acquisition system is communicatively connected to the high and low temperature control system.

[0016] In the above technical solution, blind vias are provided on the circular PCB board; the signal output interface is connected to the common port of the lower-level RF switch through a high-frequency microstrip line passing through the blind vias.

[0017] In the above technical solution, the high-frequency microstrip line is embedded in the PCB circular board.

[0018] In the above technical solution, the main control and data acquisition system includes a main control computer and a vector network analyzer; the main control computer issues control commands to the high and low temperature control system, control commands to the automatic switch switching system, and control and data acquisition commands to the vector network analyzer;

[0019] Both the signal input interface and the signal output interface are connected to the vector network analyzer via high-frequency connecting cables passing through the high and low temperature control system; the vector network analyzer transmits excitation signals to the signal input interface and receives response signals from the signal output interface.

[0020] To achieve the second objective mentioned above, the technical solution of the present invention is: a testing method for a surface-mount filter temperature characteristic testing device, characterized by comprising the following steps:

[0021] Step 1: The operator places multiple surface mount filters into the corresponding test stations and closes the high and low temperature chamber door of the high and low temperature control system; after setting the temperature curve and test parameters on the main control software of the main control computer, the test program is started.

[0022] Step 2: The high and low temperature control system drives the temperature inside the high and low temperature chamber to reach the first preset point and stabilize;

[0023] Step 3: After the temperature stabilizes, the main control computer controls the upper-layer RF switch and the lower-layer RF switch to switch channels sequentially;

[0024] Step 4: For each channel, the main control computer triggers the vector network analyzer to perform parameter scanning on the surface-mount filter of that channel and uploads the data to the main control computer for storage. The data file name includes the workstation number and temperature information.

[0025] Step 5: After all channels have been tested, the high and low temperature control system drives the temperature to the next preset point and stabilizes it;

[0026] Step 6: Repeat steps 3-5. After all temperature points have been tested, the main control computer will automatically generate a comprehensive test report.

[0027] Compared with the prior art, the present invention has the following advantages.

[0028] 1) High precision and consistency: The integrated PCB test module, multi-channel RF switches and transmission lines of consistent length minimize the uncertainty and loss of the RF path, ensuring the consistency and accuracy of test data.

[0029] 2) High efficiency: The multi-station design supports the simultaneous installation of multiple filters under test. Through automatic scanning switching, the full-temperature test of all samples can be completed in one temperature cycle, which greatly improves efficiency.

[0030] 3) High reliability: It avoids the test cables from frequently experiencing high and low temperature cycles, thus extending the equipment life.

[0031] 4) Automation and intelligence: The entire testing process (temperature control, switching, measurement, and data analysis) can be controlled by computer software, reducing human intervention and errors, realizing "one-click" fully automatic testing, reducing human operation errors, and lowering labor costs. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the structure of the present invention.

[0033] Figure 2 This is a top view of a multi-station test fixture system.

[0034] Figure 3 This is a bottom view of a multi-station test fixture system.

[0035] Among them, A-In-box test unit, B-Main control and data acquisition system, 100-Multi-station test fixture system, 110-PCB circular board, 111-Blind via, 120-Test station, 130-High frequency microstrip line, 200-High and low temperature control system, 300-Automatic switch switching system, 310-Signal input interface, 320-Signal output interface, 330-Upper layer RF switch, 340-Lower layer RF switch, Main control computer, 400-, 500-Vector network analyzer. Detailed Implementation

[0036] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings, but these descriptions are not intended to limit the invention and are merely illustrative. The advantages of the present invention will become clearer and easier to understand through this description.

[0037] Referring to the accompanying drawings, a surface mount filter temperature characteristic testing device is characterized by comprising an in-chamber testing unit A and a main control and data acquisition system B; the in-chamber testing unit A includes a multi-station testing fixture system 100, a high and low temperature control system 200, and an automatic switch switching system 300.

[0038] The multi-station test fixture system 100 is located within the high and low temperature control system 200. The multi-station test fixture system 100 includes a circular PCB board 110. Multiple test stations 120 are evenly spaced along the circumference of the upper layer of the circular PCB board 110.

[0039] The automatic switch switching system 300 includes a signal input interface 310, a signal output interface 320, an upper-layer RF switch 330, and a lower-layer RF switch 340. The signal input interface 310 and signal output interface 320 are both located on the side of the PCB circular board 110. The upper-layer RF switch 330 is located at the center of the upper layer of the PCB circular board 110, and the input pins of each test station 120 are connected to the upper-layer RF switch 330 via a high-frequency microstrip line 130. The lower-layer RF switch 340 is located on the PCB circular board. At the center of the lower layer 110, the output pins of each of the test stations 120 are connected to the lower-layer RF switch 340 via a high-frequency microstrip line 130; the signal input interface 310 is connected to the common port of the upper-layer RF switch 330 via the high-frequency microstrip line 130, and is connected to the main control and data acquisition system B via a high-frequency connection line passing through the high and low temperature control system 200; the signal output interface 320 is connected to the common port of the lower-layer RF switch 340, and is connected to the main control and data acquisition system B via a high-frequency connection line passing through the high and low temperature control system 200.

[0040] The main control and data acquisition system B is communicatively connected to the high and low temperature control system 200.

[0041] The circular PCB board 110 is provided with a blind hole 111; the signal output interface 320 is connected to the common port of the lower-level RF switch 340 through the blind hole 111 via a high-frequency microstrip line 130.

[0042] The high-frequency microstrip line 130 is embedded in the PCB circular board 110; the high-frequency microstrip line 130 transmits the probe signal to the vector network analyzer 500 outside the box with low loss.

[0043] The main control and data acquisition system B includes a main control computer 400 and a vector network analyzer 500; the main control computer 400 issues control commands to the high and low temperature control system 200, control commands to the automatic switch switching system 300, and control and data acquisition commands to the vector network analyzer 500.

[0044] Both the signal input interface 310 and the signal output interface 320 are connected to the vector network analyzer 500 via high-frequency connecting cables passing through the high and low temperature control system 200; the vector network analyzer 500 transmits excitation signals to the signal input interface 310 and receives response signals from the signal output interface 320.

[0045] A test method for a surface-mount filter temperature characteristic testing device, characterized by comprising the following steps:

[0046] Step 1: The operator places multiple surface mount filters into the corresponding test station 120 and closes the high and low temperature chamber door of the high and low temperature control system 200; after setting the temperature curve and test parameters on the main control software of the main control computer 400, the test program is started.

[0047] Step 2: The high and low temperature control system 200 drives the temperature inside the high and low temperature chamber to reach the first preset point and stabilize;

[0048] Step 3: After the temperature stabilizes, the main control computer 400 controls the upper-layer RF switch 330 and the lower-layer RF switch 340 to switch channels sequentially;

[0049] Step 4: For each channel, the main control computer 400 triggers the vector network analyzer 500 to perform parameter scanning on the surface-mount filter of that channel and uploads the data to the main control computer 400 for storage. The data file name includes the workstation number and temperature information.

[0050] Step 5: After all channels have been tested, the high and low temperature control system 200 drives the temperature to the next preset point and stabilizes it;

[0051] Step 6: Repeat steps 3-5. After all temperature points have been tested, the main control computer 400 will automatically generate a comprehensive test report.

[0052] In actual use, the multi-station test fixture system 100 is set in the high and low temperature chamber of the high and low temperature control system 200. The multi-station test fixture system 100 is used to clamp multiple surface mount filters at the same time. Each test station 120 includes a high-precision test fixture, which is used to directly contact the pads of the surface mount filter under test to achieve electrical connection and realize non-destructive and rapid clamping.

[0053] The upper layer of the PCB circular board 110 integrates a 1×10 matrix symmetrical test station 120 (which can be expanded to more test stations as needed); each test station 120 is soldered with a high-precision test fixture.

[0054] The high and low temperature control system 200 includes a sealed high and low temperature chamber, a compressor cooler, a heater, a temperature sensor, and a temperature controller; the temperature controller receives feedback signals from the temperature sensor and controls the working status of the compressor cooler and the heater, so that the temperature inside the high and low temperature chamber can be quickly and accurately cyclically controlled between -55°C and +125°C.

[0055] The automatic switch switching system 300 is used to automatically switch the test signal to any test station 120 in the multi-station test fixture system 100.

[0056] The main control computer 400 is used to control the automated operation of the entire testing process. The main control computer 400 is connected to the temperature controller, multi-channel RF switch and vector network analyzer 500 via GPIB, LAN (LXI-C type) or USB interface. The main control computer 400 has built-in control software with preset temperature and test programs, which can automatically control temperature cycling, channel switch switching, data acquisition and report generation. The main control computer 400 controls the channel switching of the multi-channel RF switch to realize the sequential scanning test of the filters at each station.

[0057] The software presets the test point temperature, constant time (e.g., 30 minutes each at -55°C, 0°C, 25°C, 85°C, and 125°C) and test procedure, automatically controls the temperature control system to cycle the temperature, automatically controls the RF switch to switch channels at each constant temperature point, and triggers the VNA to sequentially collect, store, and generate test reports for the filters at each station.

[0058] The Vector Network Analyzer 500 (VNA) is used to apply excitation signals to surface-mount filters under test and acquire response signals to measure their relevant parameters.

[0059] Since the PCB circular board 110 is circular and the high-frequency microstrip line 130 is a symmetrical line of equal length, the circular PCB layout ensures that all test stations 120 are equidistant from the center. Combined with the symmetrical microstrip line design of equal length, the problem of consistency in multi-channel measurement is fundamentally solved, the test error between different stations is reduced, and the consistency of measurement parameters is guaranteed. The isolation layer of the PCB circular board 110 is made of high-speed / high-frequency prepreg material, which can reduce signal loss and delay during transmission.

[0060] All other unspecified parts belong to the prior art.

Claims

1. A surface mount filter temperature characteristic testing device, characterized in that: It includes an in-chamber testing unit (A) and a main control and data acquisition system (B); the in-chamber testing unit (A) includes a multi-station testing fixture system (100), a high and low temperature control system (200), and an automatic switch switching system (300); The multi-station test fixture system (100) is located within the high and low temperature control system (200). The multi-station test fixture system (100) includes a PCB circular board (110). Multiple test stations (120) are evenly spaced on the upper layer of the PCB circular board (110) along the circumference. The automatic switch switching system (300) includes a signal input interface (310), a signal output interface (320), an upper-layer RF switch (330), and a lower-layer RF switch (340). The signal input interface (310) and signal output interface (320) are both located on the side of a circular PCB board (110). The upper-layer RF switch (330) is located at the center of the upper layer of the circular PCB board (110), and the input pins of each test station (120) are connected to the upper-layer RF switch (330) via a high-frequency microstrip line (130). The lower-layer RF switch (340) is located on the center of the circular PCB board (110). At the center of the lower layer of board (110), the output pins of each test station (120) are connected to the lower-layer RF switch (340) via a high-frequency microstrip line (130); the signal input interface (310) is connected to the common port of the upper-layer RF switch (330) via a high-frequency microstrip line (130) and is connected to the main control and data acquisition system (B) via a high-frequency connection line passing through the high and low temperature control system (200); the signal output interface (320) is connected to the common port of the lower-layer RF switch (340) and is connected to the main control and data acquisition system (B) via a high-frequency connection line passing through the high and low temperature control system (200). The main control and data acquisition system (B) is communicatively connected to the high and low temperature control system (200).

2. The surface mount filter temperature characteristic testing device according to claim 1, characterized in that: The PCB circular board (110) is provided with a blind via (111); the signal output interface (320) is connected to the common port of the lower-level RF switch (340) through the blind via (111) via a high-frequency microstrip line (130).

3. The surface mount filter temperature characteristic testing device according to claim 2, characterized in that: The high-frequency microstrip line (130) is embedded in the PCB circular board (110).

4. The surface mount filter temperature characteristic testing device according to claim 3, characterized in that: The main control and data acquisition system (B) includes a main control computer (400) and a vector network analyzer (500); the main control computer (400) issues control commands to the high and low temperature control system (200), issues control commands to the automatic switch switching system (300), and issues control and data acquisition commands to the vector network analyzer (500); Both the signal input interface (310) and the signal output interface (320) are connected to the vector network analyzer (500) via a high-frequency connection cable through the high and low temperature control system (200); the vector network analyzer (500) transmits an excitation signal to the signal input interface (310) and receives the response signal from the signal output interface (320).

5. A test method for a surface mount filter temperature characteristic testing device, characterized in that, Includes the following steps: Step 1: The operator places multiple surface mount filters into the corresponding test station (120), closes the high and low temperature chamber door of the high and low temperature control system (200); after setting the temperature curve and test parameters on the main control software of the main control computer (400), the test program is started. Step 2: The high and low temperature control system (200) drives the temperature inside the high and low temperature chamber to reach the first preset point and stabilize; Step 3: After the temperature stabilizes, the main control computer (400) controls the upper-layer RF switch (330) and the lower-layer RF switch (340) to switch channels sequentially; Step 4: For each channel, the main control computer (400) triggers the vector network analyzer (500) to perform parameter scanning on the surface mount filter of that channel and uploads the data to the main control computer (400) for storage. The data file name includes the workstation number and temperature information. Step 5: After all channels have been tested, the high and low temperature control system (200) drives the temperature to the next preset point and stabilizes it; Step 6: Repeat steps 3-5. After all temperature points have been tested, the main control computer (400) will automatically generate a comprehensive test report.

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