A circuit board testing machine with four-line resistance accurate measurement function

Abstract

The utility model discloses a kind of circuit board testing machines with four-line resistance accurate measurement function, it is related to circuit board testing technical field, including support seat and four-line resistance measurement mechanism, the front end of support seat is fixedly installed with control panel, the upper end of support seat is provided with positioning mechanism, the positioning mechanism includes workbench, the upper end of workbench is opened with limit slot, the upper end of workbench is fixedly installed with square frame, four end faces of square frame are all installed with telescopic link, the inside of limit slot is provided with four groups of push plate. The utility model, telescopic link and push plate cooperation in positioning mechanism, can be self-adapting adjustment according to circuit board size, realize accurate positioning clamping to different specifications circuit board, pressure sensor real-time feedback clamping pressure, avoid excessive pressure damage circuit board or pressure deficiency lead to circuit board displacement when measuring, improve measurement accuracy and stability.

Description

Technical Field

[0001] This utility model relates to the field of circuit board testing technology, and in particular to a circuit board testing machine with a four-wire resistance precision measurement function. Background Technology

[0002] With the rapid development of electronic information technology, circuit boards, as a core component of electronic products, directly affect the functionality and reliability of these products. In the circuit board manufacturing process, resistance measurement is an indispensable and crucial testing step. Accurate resistance measurement can promptly detect defects in the circuit board production process, ensuring that the circuit board meets design requirements. Currently, to overcome the large errors of the traditional two-wire resistance measurement method, circuit board testing machines using the four-wire resistance measurement method are widely used in industry production. This method, by separating the current loop and the voltage measurement loop, significantly reduces the interference of test lead resistance and contact resistance on the measurement results, greatly improving the accuracy of resistance measurement.

[0003] However, in the existing technology, there are still many problems to be solved in the circuit board fixing process of circuit board testing machines. In terms of positioning accuracy, taking pneumatic clamping devices as an example, these traditional fixing fixtures rely on simple mechanical limits to fix the circuit board during operation. In actual production, due to the lack of high-precision positioning reference, it is difficult for operators to ensure that the circuit board is in the precise position when placing it. Especially for circuit boards with high-density wiring and small-sized component layout, even a slight deviation in the position of the circuit board can cause the probe to not be accurately aligned with the pin of the resistor being measured, which will cause the probe to contact the wrong pin or have poor contact, resulting in incorrect measurement data and affecting the accuracy of product quality testing. Utility Model Content

[0004] The purpose of this invention is to solve the problems existing in the prior art by proposing a circuit board testing machine with a four-wire resistance precision measurement function.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: a circuit board testing machine with precise four-wire resistance measurement function, comprising a support base and a four-wire resistance measuring mechanism. A control panel is fixedly installed at the front end of the support base, and a positioning mechanism is provided at the upper end of the support base. The positioning mechanism includes a worktable, a limit groove is provided at the upper end of the worktable, and a square frame is fixedly installed at the upper end of the worktable. Telescopic rods are installed through the four end faces of the square frame. Four sets of push plates are provided inside the limit groove, and a latex pad is installed at one end of each set of push plates. A pressure sensor is installed through the one end of the latex pad.

[0006] Preferably, two sets of limiting rods are slidably installed through each of the four end faces of the frame, and two sets of guide rail slides are fixedly installed at the upper end of the support base.

[0007] Preferably, both sets of guide rail slides have sliders slidably installed inside, and the extended ends of the four sets of telescopic rods are respectively fixed to the other ends of the four sets of push plates.

[0008] Preferably, one end of each pair of limiting rods is fixed to the other end of a set of push plates, the upper ends of both sets of sliders are fixed to the lower end of the worktable, and the four-wire resistance measuring mechanism, the four sets of telescopic rods, and the four sets of pressure sensors are all connected to the control panel for signal connection.

[0009] Preferably, a detachable protective shell is installed at the top of the protrusion of the support base, an L-shaped frame plate is fixedly installed inside the support base, and a moving mechanism is fixedly installed inside the support base.

[0010] Preferably, the upper end of the support base has an elliptical hole through which a connector is slidably disposed, and the upper end of the L-shaped frame plate is fitted with a lifting mechanism.

[0011] Preferably, the upper end of the four-wire resistance measuring mechanism is fixed to the lower end of the movable end of the lifting mechanism, the upper end of the connector is fixed to the lower end of the worktable, the lower end of the connector is fixed to the upper end of the movable end of the moving mechanism, and both the moving mechanism and the lifting mechanism are signal connected to the control panel.

[0012] Compared with the prior art, the advantages and positive effects of this utility model are as follows:

[0013] 1. In this utility model, by setting a positioning mechanism, the telescopic rod in the positioning mechanism cooperates with the push plate to adaptively adjust according to the size of the circuit board, so as to achieve precise positioning and clamping of circuit boards of different specifications. The pressure sensor provides real-time feedback of the clamping pressure, avoiding damage to the circuit board due to excessive pressure or displacement of the circuit board during measurement due to insufficient pressure, thereby improving the accuracy and stability of measurement.

[0014] 2. In this utility model, the four-wire resistance measuring mechanism can move flexibly in the horizontal and vertical directions by setting up the moving mechanism and the lifting mechanism, which facilitates the measurement of resistance at different positions on the circuit board, expands the measurement range and improves the measurement efficiency.

[0015] 3. In this utility model, each mechanism is connected to the control panel via signal, realizing the integration and intelligence of equipment operation. Operators can complete a series of operations such as circuit board positioning, measurement mechanism movement and resistance measurement through the control panel, which reduces the difficulty of operation and improves work efficiency. Attached Figure Description

[0016] Figure 1A three-dimensional structural diagram of a circuit board testing machine with four-wire resistance precision measurement function is provided for this utility model.

[0017] Figure 2 A side view of a circuit board testing machine with four-wire resistance precision measurement function is provided for this utility model;

[0018] Figure 3 A perspective view of the positioning mechanism of a circuit board testing machine with four-wire resistance precision measurement function is provided for this utility model.

[0019] Figure 4 This utility model presents a partial perspective view of a circuit board testing machine with four-wire resistance precision measurement function.

[0020] Legend: 1. Support base; 11. Control panel; 12. Protective shell; 13. Four-wire resistance measuring mechanism; 14. L-shaped frame; 15. Moving mechanism; 16. Connector; 17. Lifting mechanism; 18. Elliptical hole; 2. Positioning mechanism; 21. Worktable; 22. Limiting groove; 23. Square frame; 24. Telescopic rod; 25. Push plate; 26. Limiting rod; 27. Latex pad; 28. Pressure sensor; 29. ​​Slider; 210. Guide rail slide. Detailed Implementation

[0021] To better understand the above-mentioned objectives, features, and advantages of this utility model, the present utility model will be further described below with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0022] Many specific details are set forth in the following description in order to provide a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the present invention is not limited to the specific embodiments disclosed in the following specification.

[0023] Example 1: As Figure 1 , Figure 2 , Figure 3 and Figure 4As shown, this utility model provides a circuit board testing machine with precise four-wire resistance measurement function, including a support base 1 and a four-wire resistance measuring mechanism 13. A control panel 11 is fixedly installed at the front end of the support base 1, and a positioning mechanism 2 is provided at the upper end of the support base 1. The positioning mechanism 2 includes a worktable 21, a limit groove 22 is formed at the upper end of the worktable 21, and a square frame 23 is fixedly installed at the upper end of the worktable 21. Telescopic rods 24 are installed through the four end faces of the square frame 23. Four sets of push plates 25 are arranged inside the limit groove 22, and a latex pad 27 is installed at one end of each set of push plates 25. A pressure sensor 28 is installed through the frame. Two sets of limit rods 26 are slidably installed through the four end faces of the frame 23. Two sets of guide rail slides 210 are fixedly installed on the upper end of the support base 1. Slider 29 is slidably installed inside the two sets of guide rail slides 210. The extended ends of the four sets of telescopic rods 24 are fixed to the other ends of the four sets of push plates 25 respectively. One end of every two sets of limit rods 26 is fixed to the other end of a set of push plates 25. The upper ends of the two sets of sliders 29 are fixed to the lower end of the worktable 21. The four-wire resistance measuring mechanism 13, the four sets of telescopic rods 24 and the four sets of pressure sensors 28 are all connected to the control panel 11.

[0024] The specific settings and functions of this embodiment are described in detail below. The support base 1 serves as the basic component, with the control panel 11 fixedly installed at the front end for controlling the operation of the entire testing machine. A detachable protective shell 12 is installed at the top of the protrusion to protect the internal key components. An L-shaped frame plate 14 is fixedly installed inside to provide installation support for other components. An elliptical hole 18 is also provided through the upper end for cooperating with the connector 16 to realize the movement of related components.

[0025] The positioning mechanism 2 includes a worktable 21 with a limiting groove 22 at its upper end for initially placing the circuit board; on the fixedly installed square frame 23, telescopic rods 24 are installed through all four end faces, and two sets of limiting rods 26 are slidably installed through them. The limiting groove 22 is equipped with four sets of push plates 25. A latex pad 27 is installed at one end of the push plate 25. A pressure sensor 28 is installed through the latex pad 27. The extended ends of the four sets of telescopic rods 24 are fixed to the four sets of push plates 25. One end of every two sets of limiting rods 26 is also fixed to one set of push plates 25. The upper ends of the two sets of sliders 29 are fixed to the lower end of the worktable 21. The sliders 29 slide in the guide rail slide 210. The telescopic rods 24 are extended and retracted by the control panel 11, which drives the push plates 25 to move. The four sets of push plates 25 drive the four sets of latex pads 27 to contact the four end faces of the circuit board, thereby limiting the circuit board and realizing the clamping and positioning of circuit boards of different sizes. This allows for adaptive adjustment according to the size of the circuit board, achieving precise positioning and clamping of circuit boards of different specifications. The pressure sensor 28 provides real-time feedback of the clamping pressure, avoiding damage to the circuit board due to excessive pressure or displacement of the circuit board during measurement due to insufficient pressure, thus improving the accuracy and stability of the measurement.

[0026] When the worktable 21 moves, it will drive the two sets of sliders 29 to move. The two sets of sliders 29 slide inside the guide rail slide 210, which can guide the worktable 21 and improve the stability of the worktable 21 when it moves.

[0027] The four sets of latex pads 27 provide protection when clamping the circuit board, preventing damage to the four ends of the circuit board.

[0028] Example 2: Figure 1 , Figure 2 and Figure 4 As shown, a detachable protective shell 12 is installed on the top of the protrusion of the support base 1. An L-shaped frame plate 14 is fixedly installed inside the support base 1. A moving mechanism 15 is fixedly installed inside the support base 1. An elliptical hole 18 is opened through the upper end of the support base 1. A connector 16 is slidably arranged inside the elliptical hole 18. A lifting mechanism 17 is installed through the upper end of the L-shaped frame plate 14. The upper end of the four-wire resistance measuring mechanism 13 is fixed to the lower end of the movable end of the lifting mechanism 17. The upper end of the connector 16 is fixed to the lower end of the worktable 21. The lower end of the connector 16 is fixed to the upper end of the movable end of the moving mechanism 15. The moving mechanism 15 and the lifting mechanism 17 are both connected to the control panel 11 via signals.

[0029] The overall effect of this embodiment is that the four-wire resistance measuring mechanism 13 is used to realize the resistance measurement function. Its upper end is fixed to the lower end of the movable end of the lifting mechanism 17, and it can move up and down under the action of the lifting mechanism 17. The lower end of the connector 16 is fixed to the upper end of the movable end of the moving mechanism 15, and its upper end is fixed to the lower end of the worktable 21. Under the action of the moving mechanism 15, it can drive the worktable 21 and the circuit board to move in the horizontal direction. The moving mechanism 15, the lifting mechanism 17 and the four-wire resistance measuring mechanism 13 are all connected to the control panel 11 for signal connection, and precise control is realized through the control panel 11.

[0030] The detachable protective shell 12 can effectively protect the key components inside the support base 1, reduce the intrusion of dust and debris, and extend the service life of the equipment; at the same time, the detachable design of the protective shell 12 facilitates the inspection and maintenance of the internal components; the L-shaped frame plate 14 can provide support for the lifting mechanism 17.

[0031] The usage and working principle of this device: When the operator is about to perform resistance measurement on the circuit board, the circuit board to be tested is first placed in the limiting groove 22 of the workbench 21. The limiting groove 22 plays a preliminary positioning role for the circuit board, making it convenient for the operator to quickly place the circuit board in a roughly accurate position.

[0032] Subsequently, the operator inputs the circuit board size information or selects the corresponding circuit board model through the control panel 11. After receiving the information, the control panel 11 processes it according to the preset program and sends control signals to the four sets of telescopic rods 24 in the positioning mechanism 2. After receiving the signal, the telescopic rods 24 will move synchronously, driving the four sets of push plates 25 connected to them to move towards the circuit board. During the movement of the push plates 25, the pressure sensor 28 installed inside the latex pad 27 monitors the pressure applied by the push plates 25 to the circuit board in real time and converts the pressure signal into an electrical signal to feed back to the control panel 11. The control panel 11 compares the received pressure signal with the preset pressure threshold. When the pressure reaches the appropriate range, the control panel 11 sends a stop signal to the telescopic rods 24 to stop their operation. At this time, the push plates 25 firmly and stably clamp the circuit board onto the worktable 21 through the latex pad 27. At the same time, the limit rods 26 fixedly connected to each pair of push plates 25 further ensure that the push plates 25 do not deviate during the clamping process and ensure that the clamping force is evenly distributed around the circuit board.

[0033] Then, after the circuit board is fixed, the control panel 11 sends a command to the moving mechanism 15. The primary linear motor of the moving mechanism 15 interacts with the secondary aluminum alloy guide rail under the action of the magnetic field generated by the high-performance rare earth permanent magnet material, generating a linear driving force. According to the command of the control panel 11, the linear motor drives the connector 16 to slide in the elliptical hole 18 at a set speed, thereby driving the worktable 21 and the circuit board to move in the horizontal direction, moving the position of the resistor to be measured on the circuit board to a suitable area below the four-wire resistance measuring mechanism 13.

[0034] Finally, the control panel 11 controls the lifting mechanism 17 to work. After receiving the instruction, the lifting mechanism 17 will drive the vertical linear movement of the four-wire resistance measuring mechanism 13. The four-wire resistance measuring mechanism 13 moves downward at a set speed and accuracy. Its four probes gradually approach the resistor pins on the circuit board. When the probes contact the resistor pins, the internal pressure springs provide stable contact pressure to ensure good contact between the probes and the pins.

[0035] At this time, the four-wire resistance measuring mechanism 13 starts to work. Its internal high-precision constant current source provides a stable constant current to the resistor under test. The high-impedance voltage measuring circuit measures the voltage across the resistor under test through the voltage input probe and the voltage output probe. The measured voltage signal is transmitted to the signal processing unit. The signal processing unit calculates the resistance value of the resistor under test according to Ohm's law. The calculation result is transmitted to the control panel 11 through the internal data bus. The control panel 11 displays the resistance measurement value on the touch screen and stores the measurement data in the internal data storage module for easy viewing and subsequent analysis by the operator.

[0036] The above are merely preferred embodiments of this utility model and are not intended to limit the utility model in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments for application in other fields. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of this utility model without departing from the technical solution of this utility model shall still fall within the protection scope of this utility model.

Claims

1. A circuit board testing machine with precise four-wire resistance measurement function, comprising a support base (1) and a four-wire resistance measuring mechanism (13), characterized in that: A control panel (11) is fixedly installed at the front end of the support base (1). A positioning mechanism (2) is provided at the upper end of the support base (1). The positioning mechanism (2) includes a workbench (21). A limit groove (22) is opened at the upper end of the workbench (21). A square frame (23) is fixedly installed at the upper end of the workbench (21). Telescopic rods (24) are installed through the four end faces of the square frame (23). Four sets of push plates (25) are provided inside the limit groove (22). A latex pad (27) is installed at one end of each set of push plates (25). A pressure sensor (28) is installed through the one end of the latex pad (27).

2. The circuit board testing machine with four-wire resistance precision measurement function according to claim 1, characterized in that: Two sets of limiting rods (26) are slidably installed through the four end faces of the frame (23), and two sets of guide rail slides (210) are fixedly installed on the upper end of the support base (1).

3. A circuit board testing machine with four-wire resistance precision measurement function according to claim 2, characterized in that: Both sets of guide rail slides (210) have sliders (29) slidably installed inside, and the extended ends of the four sets of telescopic rods (24) are respectively fixed to the other ends of the four sets of push plates (25).

4. A circuit board testing machine with four-wire resistance precision measurement function according to claim 3, characterized in that: One end of each pair of limit rods (26) is fixed to the other end of a set of push plates (25), the upper ends of the two sets of sliders (29) are fixed to the lower end of the worktable (21), and the four-wire resistance measuring mechanism (13), the four sets of telescopic rods (24) and the four sets of pressure sensors (28) are all connected to the control panel (11) via signal.

5. A circuit board testing machine with four-wire resistance precision measurement function according to claim 1, characterized in that: The top of the protrusion of the support base (1) is equipped with a detachable protective shell (12), and an L-shaped frame plate (14) is fixedly installed inside the support base (1). A moving mechanism (15) is fixedly installed inside the support base (1).

6. A circuit board testing machine with four-wire resistance precision measurement function according to claim 5, characterized in that: The upper end of the support base (1) is provided with an elliptical hole (18), and a connector (16) is slidably arranged inside the elliptical hole (18). The upper end of the L-shaped frame plate (14) is provided with a lifting mechanism (17).

7. A circuit board testing machine with four-wire resistance precision measurement function according to claim 6, characterized in that: The upper end of the four-wire resistance measuring mechanism (13) is fixed to the lower end of the movable end of the lifting mechanism (17), the upper end of the connector (16) is fixed to the lower end of the worktable (21), and the lower end of the connector (16) is fixed to the upper end of the movable end of the moving mechanism (15). The moving mechanism (15) and the lifting mechanism (17) are both connected to the control panel (11) via signal.

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