Thick-film resistor TCR performance testing device

Abstract

The invention discloses a device for testing the performance of a thick-film resistor TCR in the technical field of electrical variable testing, and aims to solve the problem that the efficiency of measuring the performance of the thick-film resistor TCR by changing the environment temperature is too low in the prior art. The device comprises a test line used for conveying a carrier, the carrier carries a thick-film resistor disc, a plurality of driving assemblies are arranged on one side of the test line in the conveying direction of the test line, the output end of each driving assembly is provided with a driving rod, and the driving assemblies at least can drive the driving rods to move in the vertical direction. A heat exchange block is fixedly mounted at the lower end of each driving rod, the temperatures of the multiple heat exchange blocks are gradually increased in the conveying direction of the test line, an adjusting plate is further arranged above the heat exchange blocks, and a probe capable of penetrating through the heat exchange blocks is slidably arranged on the adjusting plate in the vertical direction; the device is used for efficiently and rapidly measuring the TCR performance of the thick-film resistor, temperature control detection on the surface of the thick-film resistor can be rapidly achieved, and energy is saved.

Description

Technical Field

[0001] This invention relates to a thick film resistor TCR performance testing device, belonging to the field of electrical variable testing technology. Background Technology

[0002] Thick-film resistors are resistor sheets formed by printing resistive paste onto a ceramic substrate using screen printing technology, followed by high-temperature sintering and curing. The resistance value of these resistor sheets can be altered through laser engraving to suit various applications. To ensure the stability of thick-film resistor products, the manufactured resistors typically undergo electrical testing to guarantee that their performance meets application requirements.

[0003] In addition to testing the resistance value, qualified thick-film resistors also need to have their TCR (temperature coefficient) performance measured at different temperatures, i.e., how the resistance value behaves at different temperatures. The traditional method is to use a temperature-controlled chamber and measure the resistance value of the thick-film resistor at the corresponding temperature by changing the stable temperature of the chamber. However, since the TCR performance test requires measuring the resistance change at least two sets of different ambient temperatures, this method also requires changing the ambient temperature inside the chamber. In automated production line testing, this method is extremely time-consuming. Because the ceramic substrate of the resistor has a large specific heat capacity, the heat conduction process is also extremely energy-intensive and the time required to affect the ambient temperature also affects the efficiency of testing the TCR performance of thick-film resistors. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a thick film resistor TCR performance testing device for efficient and rapid measurement of the TCR performance of thick film resistors. It can quickly realize temperature-controlled detection of the surface of thick film resistors and save energy.

[0005] To achieve the above objectives, the present invention employs the following technical solution: This invention provides a thick-film resistor TCR performance testing device, comprising a test line for a transport carrier, on which a thick-film resistor is mounted. Multiple drive components are arranged along the transport direction of the test line on one side. Each drive component has a drive rod at its output end, and each drive component can at least drive the drive rod to move vertically. A heat exchange block is fixedly installed at the lower end of each drive rod. The temperature of the multiple heat exchange blocks gradually increases along the transport direction of the test line. An adjustment plate is also provided above the heat exchange blocks. At least two sets of probes are slidably mounted on the adjustment plate in the vertical direction, penetrating the heat exchange blocks. A positioning plate is fixedly mounted on each probe between the adjustment plate and the heat exchange blocks. A pressure sensor is provided at the bottom of the adjustment plate. First springs are sleeved on the probes, with their two sides respectively contacting the positioning plate and the pressure sensor.

[0006] Specifically, a base is fixedly installed above the heat exchange block, and the adjusting plate is slidably installed on the base in the vertical direction. The base is also provided with a positioning mechanism for positioning the adjusting plate.

[0007] Specifically, the temperature of the heat exchange block located at the upstream end of the test line is not higher than -45℃, and the temperature of the heat exchange block located at the downstream end of the test line is not lower than 125℃.

[0008] Specifically, the heat exchange block is functionally divided into a cooling block and a heating block. The cooling block and the heating block are respectively equipped with a cooling medium and a heating medium. A temperature sensor is provided on the surface of the heat exchange block. A positioning frame is installed below the cooling block and the heating block. The bottom of the positioning frame is set as an opening and an elastic sealing membrane is provided at the opening position. The positioning frame is filled with thermally conductive silicone grease. Guide holes are provided at the positions of the cooling block, the heating block, the positioning frame and the elastic sealing membrane for the probe to pass through.

[0009] Specifically, it also includes a connecting piece, an overflow pipe connected to one side of the positioning frame, a U-shaped frame connected to one side of the heat exchange block, a piston rod and a movable rod respectively installed at both ends of the connecting piece, the piston rod being slidably disposed in the overflow pipe, the movable rod being slidably disposed through the U-shaped frame and a sliding plate being disposed at the other end of the movable rod, a second spring being sleeved on the movable rod with its two sides respectively abutting against the sliding plate and the wall of the U-shaped frame, a U-shaped photoelectric sensor being disposed on the U-shaped frame, and the sliding plate being able to pass through the detection position of the U-shaped photoelectric sensor.

[0010] Specifically, at least two sets of U-shaped photoelectric sensors are provided, and after the elastic sealing film detaches from the surface of the thick film resistor, the second spring can drive the movable slider to move to a position outside the two sets of U-shaped photoelectric sensors.

[0011] Specifically, the cooling block is divided into upper and lower cavities by a partition. The upper cavity is equipped with a labyrinth heat exchange plate and is filled with cooling gas. The lower cavity is filled with coolant. The heat exchange block is equipped with an insulation layer on its outer side.

[0012] Specifically, the downstream refrigeration block is connected to the main air intake pipe that connects to the upper cavity of the refrigeration block, and a first air intake pipe and a second air intake pipe are also connected. The first air intake pipe is used to access high-pressure cold air, and the second air intake pipe is connected to the exhaust port of another adjacent upstream refrigeration block. Both the first air intake pipe and the second air intake pipe are equipped with electromagnetic flow valves.

[0013] Specifically, the internal cavity of the heating block is filled with heat-conducting oil, and the heating block is equipped with an electric heating tube for heating the heat-conducting oil.

[0014] Specifically, a return line is provided on one side of the test line, and a sorting device is provided between the test line and the return line. An air blowing assembly is also provided on the test line between the cooling block and the heating block. The air blowing assembly is used to blow air onto the thick film resistor sheet on the surface of the test line.

[0015] Compared with the prior art, the beneficial effects achieved by the present invention are as follows: This invention features multiple detection modules arranged around the periphery of the detection line. Each module has a heat exchange block at a different temperature for direct contact with the surface of the thick-film resistor. Upon contact, a probe passes through the heat exchange block and contacts the test point to measure the resistance at the corresponding ambient temperature. A pressure sensor detects the pressure of the probe, preventing excessive pressure at the test point from amplifying the resistance measurement error. The detection line uses a step-by-step method to transport the thick-film resistor sheet for measurement, allowing for rapid and direct measurement of resistance values ​​at different ambient temperatures at various workstations. This enables quick determination of the TCR performance data of the thick-film resistor. The device requires no insulation chamber and no heat exchange on the ceramic substrate, saving energy, with a simple structure and convenient and efficient operation, providing rapid TCR performance data for the tested resistor.

[0016] This invention improves the contact surface between the resistor and the heat exchange block by using fluid-state thermally conductive silicone grease to contact the surface of the thick film resistor. This avoids excessive surface pressure from the heat exchange block on the thick film resistor, which could affect the accurate measurement of the resistance value. This helps to reduce measurement errors and ensure the accuracy of test results. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall structure of the TCR performance testing device provided in this embodiment of the invention; Figure 2 This is the present invention. Figure 1 Enlarged view of section A of the TCR performance testing device provided in the embodiment; Figure 3 This is the present invention. Figure 1 Enlarged view of section B of the TCR performance testing device provided in the embodiment; Figure 4 This is a schematic diagram of the structure of the refrigeration component provided in an embodiment of the present invention; Figure 5 This is the present invention. Figure 4 Enlarged view of the structure at point C of the refrigeration component provided in the embodiment; Figure 6 This is a top view of the refrigeration component provided in an embodiment of the present invention; Figure 7 This is the present invention. Figure 6 A DD-direction cross-sectional view of the cooling component provided in the embodiment; Figure 8 This is the present invention. Figure 7 An enlarged view of the structure at point E of the refrigeration component provided in the embodiment; Figure 9 This is the present invention. Figure 7 Enlarged view of the structure at point F of the refrigeration component provided in the embodiment; Figure 10 This is a top view of the heating component provided in an embodiment of the present invention; Figure 11 This is the present invention. Figure 10 A cross-sectional view of the heating component provided in the embodiment; Figure 12 This is the present invention. Figure 11 Enlarged view of the structure at point H of the heating component provided in the embodiment; Reference numerals: 1. Test line; 2. Carrier; 3. Drive assembly; 4. Drive rod; 5. Heat exchange block; 6. Adjustment plate; 7. Probe; 8. Positioning plate; 9. First spring; 10. Pressure sensor; 11. Base; 12. Temperature sensor; 13. Positioning frame; 14. Elastic sealing membrane; 15. Overflow pipe; 16. U-shaped frame; 17. Connecting piece; 18. Piston rod; 19. Movable rod; 20. Second spring; 21. U-shaped photoelectric sensor; 22. Sliding plate; 23. Supply pipe; 24. Sealing head; 25. Partition plate; 26. Labyrinth heat exchange plate; 27. Insulation layer; 28. Main air inlet pipe; 29. ​​First air inlet pipe; 30. Second air inlet pipe; 31. Electromagnetic flow valve; 32. Heating element; 33. Air blowing assembly; 34. Return line; 35. Sorting device. Detailed Implementation

[0018] The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and should not be used to limit the scope of protection of the present invention.

[0019] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are used only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0020] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0021] This invention provides a thick-film resistor TCR performance testing device for efficient and rapid measurement of the TCR performance of thick-film resistors. It can quickly achieve temperature-controlled surface testing of the thick-film resistor, saving energy. To realize the structural function of the device, it includes a test line 1 for conveying a carrier 2. The test line 1 preferably adopts a conveyor belt structure with a limiting function to position the carrier 2 for testing. The carrier 2 is equipped with a thick-film resistor sheet, thereby positioning the thick-film resistor sheet by limiting the position of the carrier 2. To quickly obtain the TCR performance of the resistor under test, multiple drive components 3 can be arranged along the conveying direction of the test line 1 on one side. Figure 1 as well as Figure 4 As shown, each drive assembly 3 has a drive rod 4 at its output end. The drive assembly 3 can at least drive the drive rod 4 to move in the vertical direction. Preferably, in order to prevent the position of the tested thick film resistor from shifting and causing inaccurate detection point position, the structure of the drive assembly 3 can be configured as follows: Figure 4 As shown, through multi-directional rotation and lifting movements, the control drive rod 4 can rotate and move laterally within a spatial range, allowing the probe 7 mounted on the drive rod 4 to accurately move to the detection position (position adjustment requires the use of a recognition camera). The specific structural components are not detailed here. To quickly bring the surface of the thick-film resistor to the measured temperature, a heat exchange block 5 is fixedly installed at the lower end of each drive rod 4. The heat exchange block 5 directly contacts the surface of the resistor being measured, achieving direct cooling or heating of the resistor film. Multiple heat exchange blocks 5 are configured, with the temperature gradually increasing along the transport direction of the test line 1. At least two sets of heat exchange blocks 5 are used to measure the difference in resistance when the temperature changes, thereby obtaining relevant TCR performance parameters. During testing, the heat exchange blocks 5 do not detach from the surface of the thick-film resistor, thus obtaining resistance data at a stable temperature. To achieve contact testing of the probe 7 when the heat exchange blocks 5 are pressed, an adjustment plate 6 is also provided above the heat exchange blocks 5. (See reference...) Figure 8As shown, a probe 7 capable of penetrating the heat exchange block 5 is slidably mounted on the adjusting plate 6 along the vertical direction. At least two sets of probes 7 are configured to connect with corresponding contact points on the thick-film resistor. To prevent excessive pressure on the thick-film resistor from the probes 7 or the heat exchange block 5, a positioning disk 8 is fixedly mounted on the probe 7 between the adjusting plate 6 and the heat exchange block 5. A pressure sensor 10 is installed at the bottom of the adjusting plate 6. Finally, a first spring 9 is fitted onto the probe 7, with its two sides respectively abutting against the positioning disk 8 and the pressure sensor 10. Figure 8 As shown, with this structural connection, when the device is working, the probe 7 first contacts the test point of the thick film resistor being measured. Then, the heat exchange block 5 continues to press down, and the probe 7 rebounds under the force of the first spring 9 until the heat exchange surface at the lower end of the heat exchange block 5 contacts the surface of the thick film resistor. The first spring 9 is compressed to the working position to measure the current pressure value. The heat exchange surface at the lower end of the heat exchange block 5 can be made of an elastic layer, giving it a certain degree of height fine-tuning capability. This allows the pressure of the probe 7 on the thick film resistor to be changed during detection, avoiding the influence of excessive pressure on the resistance measurement. Alternatively, if the pressure sensor 10 detects excessive pressure after the heat exchange block 5 moves to the contact position, manual adjustment can be made through an alert, thereby improving the pressure range of the probe 7 during operation. Through the above structural design, the device can quickly measure the resistance value under different temperature conditions during the conveying of thick film resistors, thereby efficiently obtaining the resistance parameters and TCR performance of the corresponding thick film resistors. This allows for the rapid detection of defective products for secondary repair or scrapping, without the need for additional temperature control environment preparation, which helps to ensure energy utilization efficiency and reduce energy consumption.

[0022] The present invention provides a thick-film resistor TCR performance testing device, which facilitates the adjustment of the pressure of the probe 7 during operation, such as... Figure 8 As shown, a base 11 is fixedly installed above the heat exchange block 5. An adjusting plate 6 is slidably installed on the base 11 in the vertical direction, and a positioning mechanism for positioning the adjusting plate 6 is also provided on the base 11. According to the above embodiment, when the heat exchange block 5 contacts the surface of the thick film resistor, if the compression length of the first spring 9 is too large, it indicates that the probe 7 is exerting considerable pressure on the test point. When the pressure at the test point is too high, by adjusting the position of the adjusting plate 6 by a certain distance, the compression of the first spring 9 can be shortened, thereby reducing the pressure of the probe 7 on the test point until the pressure range is adjusted to the allowable range during testing.

[0023] This invention provides a thick-film resistor TCR performance testing device. To improve the accuracy of the measured TCR data and to assess the resistance performance of the thick-film resistor under different ambient temperatures, the temperature of the heat exchange block 5 located at the upstream end of test line 1 is set not higher than -45℃, and the temperature of the heat exchange block 5 located at the downstream end of test line 1 is set not lower than 125℃. This increases the temperature difference between the upstream and downstream sides to obtain more accurate TCR data. To accommodate this temperature difference, the heat exchange block 5 can be functionally divided into a cooling block and a heating block. The cooling block and heating block are respectively equipped with a cooling medium and a heating medium. The cooling medium is preferably propylene glycol (freezing point -60℃ to -50℃) to avoid damage to the structure due to solidification expansion. The heating medium is preferably heat-conducting oil. A temperature sensor 12 is provided on the surface of the heat exchange block 5 to detect the temperature of the cooling and heating media. To avoid excessive pressure on the thick-film resistor from the heat exchange block 5 itself, flexible contact can be used to further reduce the pressure on the thick-film resistor. For details, please refer to... Figure 8 As shown, a positioning frame 13 is installed below both the cooling block and the heating block. The bottom of the positioning frame 13 is set as an opening, and an elastic sealing membrane 14 is provided at the opening position. Thermally conductive silicone grease is filled inside the positioning frame 13. After the thermally conductive silicone grease is filled, the elastic sealing membrane 14 protrudes from the bottom surface of the positioning frame 13. At this time, the thermally conductive silicone grease exchanges heat with the heat exchange block 5 above, and contacts the surface of the thick film resistor below through the elastic sealing membrane 14. Since the thermally conductive silicone grease can maintain a fluid state in the test range of -50℃ to 125℃, the actual pressure is lower than that of other elastic materials, and it has a high deformation capacity, which can also ensure good contact with the thick film resistor sheet. During the test, guide holes are provided at the positions between the cooling block, the heating block, the positioning frame 13 and the elastic sealing membrane 14 for the probe 7 to pass through. This structural design utilizes the excellent thermal conductivity of thermally conductive silicone grease to achieve precise temperature transfer. Furthermore, being in a fluid state, it can provide lower pressure while maintaining significant deformation capacity, thereby reducing data measurement errors. It also avoids irreversible pressure damage to the resistor sheet caused by impurities on its surface during downward pressure. In addition, the bottom of the probe 7 preferably features a 45° bend, which, compared to directly placing the elastic layer at the bottom of the heat exchange block 5, provides better compatibility with the elastic sealing membrane 14, preventing situations where the bottom of the probe 7 contacts the thick-film resistor sheet but the elastic layer fails to make proper contact. In some preferred embodiments, refer to... Figure 12 As shown, by providing a supply pipe 23 on one side of the positioning frame 13, it is convenient to replace and refill the thermal grease inside it. A sealing head 24 is provided on the open side of the supply pipe 23 to ensure a closed environment when the thermal grease is working.

[0024] This invention provides a thick-film resistor TCR performance testing device, such as... Figure 4 , Figure 5 as well as Figure 9As shown, when using thermally conductive silicone grease and an elastic sealing film 14 to contact the thick film resistor being tested, it is difficult to determine whether the elastic sealing film 14 is properly pressed against the surface of the thick film resistor. Therefore, it is necessary to provide a parameter that is easy to measure to determine the contact condition of the elastic sealing film 14. To facilitate the conversion of this inconveniently measured parameter, the device here also includes a connecting piece 17. Specifically, an overflow pipe 15 is connected to one side of the positioning frame 13, and a U-shaped frame 16 is connected to one side of the heat exchange block 5. A piston rod 18 and a movable rod 19 are respectively installed at both ends of the connecting piece 17. The piston rod 18 is slidably positioned inside the overflow pipe 15. The movable rod 19 is configured to slide through the U-shaped frame 16, and a sliding plate 22 is provided at the other end of the movable rod 19. A second spring 20 is sleeved on the movable rod 19, with its two sides respectively abutting against the sliding plate 22 and the wall of the U-shaped frame 16. With this configuration, the first Under normal conditions, the second spring 20 abuts against the slider 22, causing the piston rod 18 to compress the thermal grease, thereby increasing the pressure of the thermal grease inside the positioning frame 13. This causes the elastic sealing film 14 to tend to bulge downwards. When the elastic sealing film 14 contacts the surface of the resistor being tested, as the contact area increases and the compression intensifies, the piston rod 18 will cause the slider 22 to abut against the second spring 20 and move to the other side. Thus, the amount of displacement of the moving position can be used to determine whether the elastic sealing film 14 has achieved reliable contact. For this purpose, a U-shaped photoelectric sensor 21 is provided on the U-shaped frame 16. The slider 22 is configured to detect the position of the U-shaped photoelectric sensor 21, thereby measuring the deformation of the elastic sealing film 14. Based on the surface area of ​​the overflow tube 15 and the pressure obtained from the position of the second spring 20, the pressure of the thermal grease can be roughly calculated. It is preferable to control the pressure of the thermal grease to be within 0.02 MPa. In addition to detecting the deformation of the elastic sealing membrane 14, it is also necessary to consider the potential risk of the positioning frame 13 directly contacting the surface of the thick film resistor due to excessive movement. To this end, at least two sets of U-shaped photoelectric sensors 21 are required. After the elastic sealing membrane 14 is removed from the surface of the thick film resistor, the second spring 20 can drive the slider 22 to move to a position outside the two sets of U-shaped photoelectric sensors 21. The position of the first U-shaped photoelectric sensor 21 is located at the position where the elastic sealing membrane 14 and the thick film resistor can make reliable contact. The position of the second U-shaped photoelectric sensor 21 is located at the extreme position where the elastic sealing membrane 14 is squeezed. During operation, when the slider 22 is between the two U-shaped photoelectric sensors 21, it is in normal working condition. When an abnormality occurs, an alarm is triggered and manual repair is required.It should be noted that when adjusting the pressure of the probe 7, the appropriate pressure range of the probe 7 should be matched with the normal working range of the elastic sealing diaphragm 14. If the probe 7 cannot work under the appropriate pressure when the slider 22 is located between the two U-shaped photoelectric sensors 21, it means that the drive rod 4 cannot meet the pressure control requirements of the probe 7 at the corresponding height position. In this case, the position of the adjustment plate 6 needs to be readjusted so that the probe 7 and the elastic sealing diaphragm 14 can be adapted at the same time.

[0025] This invention provides a thick-film resistor TCR performance testing device, specifically providing the operating structure and principle of a cooling block. Specifically, the cooling block is configured with an internal partition 25 dividing it into upper and lower cavities. Figure 8 As shown, a labyrinthine heat exchange plate 26 can be installed inside the upper cavity, and a cooling gas is introduced into the upper cavity. A coolant (such as propylene glycol) is installed inside the lower cavity. During operation, the cooling gas (such as liquid nitrogen) quickly cools down the labyrinthine heat exchange plate 26 through the labyrinthine heat exchange plate 26, and then radiates the low temperature to the coolant in the lower cavity through heat conduction of the labyrinthine heat exchange plate 26. The temperature of the coolant is detected by the temperature sensor 12 so that the coolant contacts the surface of the thick film resistor within a suitable temperature range to achieve heat exchange. The cooling capacity is adjusted by controlling the flow rate of the cooling gas. The specific heat capacity of the coolant and the relatively stable temperature change are used to avoid large temperature differences during testing. To avoid the influence of environmental heat exchange, an insulation layer 27 can be installed on the outside of the heat exchange block 5 to prevent the cold source from dissipating rapidly and increasing the application cost.

[0026] The thick film resistor TCR performance testing device provided in this embodiment of the invention considers that the required temperature of the downstream refrigeration block is higher than that of the upstream refrigeration block. Therefore, in some other embodiments, in order to further effectively utilize the refrigeration source, a first air inlet pipe 29 and a second air inlet pipe 30 can be connected to the main air inlet pipe 28 connecting the upper cavity of the downstream refrigeration block. The first air inlet pipe 29 is configured to connect to high-pressure cold air, and the second air inlet pipe 30 is configured to connect to the exhaust port of another adjacent upstream refrigeration block. At this time, the cold air source of the downstream refrigeration block can be mainly supplied by the exhaust pipe of the upstream. When the low temperature requirement cannot be met, the high-pressure cold air connected by the first air inlet pipe 29 is used to achieve mixing and cooling so that the mixed gas can meet the usage requirements. In order to facilitate the adjustment of the air flow ratio of the first air inlet pipe 29 and the second air inlet pipe 30 according to the feedback of the temperature sensor 12, electromagnetic flow valves 31 are required on both the first air inlet pipe 29 and the second air inlet pipe 30 to control the relative flow of the two pipes.

[0027] The thick film resistor TCR performance testing device provided in this embodiment of the invention can fill the cavity inside the heat exchange block 5 with heat transfer oil to meet the heating requirements. By providing an electric heating tube 32 inside the heat exchange block for heating the heat transfer oil, the temperature of the heat transfer oil can be directly increased. Similarly, the temperature range can be detected and controlled by the corresponding temperature sensor 12.

[0028] In some preferred embodiments of the thick-film resistor TCR performance testing device provided by this invention, to facilitate the rejection of defective thick-film resistor sheets, a return line 34 is also provided on one side of the test line 1. A sorting device 35 or a sorting robot is provided between the test line 1 and the return line 34 to classify products of different qualities in the return line 34, allowing them to flow out at different widths according to their quality differences, thus achieving precise screening. To avoid water droplets condensing on the surface of the thick-film resistor sheet after low-temperature testing, which could affect the test results, an air blowing assembly 33 is provided on the test line 1 between the cooling block and the heating block. The air blowing assembly 33 is used to blow air onto the thick-film resistor sheet on the surface of the test line 1, where the air source can be heated to quickly dry the surface of the resistor sheet. However, the test environment is preferably a dry factory workshop, which also helps to prevent ice crystals from condensing on the long-term working surface of the elastic sealing membrane 14, and requires regular and timely cleaning.

[0029] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A thick-film resistor TCR performance testing device, characterized in that, The test line (1) includes a transport carrier (2) on which a thick-film resistor is mounted. Multiple drive components (3) are arranged along the transport direction of the test line (1) on one side. Each drive component (3) has a drive rod (4) at its output end. The drive component (3) is capable of driving the drive rod (4) to move vertically. A heat exchange block (5) is fixedly installed at the lower end of each drive rod (4). The temperature of the multiple heat exchange blocks (5) gradually increases along the transport direction of the test line (1). An adjustment plate (6) is also provided above the heat exchange block (5). A probe (7) that can penetrate the heat exchange block (5) is slidably provided on the adjustment plate (6) in the vertical direction. There are no less than two sets of probes (7). A positioning plate (8) located between the adjustment plate (6) and the heat exchange block (5) is fixedly installed on the probe (7). A pressure sensor (10) is provided at the bottom of the adjustment plate (6). A first spring (9) is sleeved on the probe (7) and its two sides abut against the positioning plate (8) and the pressure sensor (10) respectively.

2. The thick-film resistor TCR performance testing device according to claim 1, characterized in that, A base (11) is fixedly installed above the heat exchange block (5), and the adjusting plate (6) is slidably installed on the base (11) in the vertical direction. The base (11) is also provided with a positioning mechanism for positioning the adjusting plate (6).

3. The thick-film resistor TCR performance testing device according to claim 1, characterized in that, The temperature of the heat exchange block (5) located at the upstream end of the test line (1) is not higher than -45℃, and the temperature of the heat exchange block (5) located at the downstream end of the test line (1) is not lower than 125℃.

4. The thick-film resistor TCR performance testing device according to claim 3, characterized in that, The heat exchange block (5) is divided into a cooling block and a heating block according to its function. The cooling block and the heating block are respectively provided with a cooling medium and a heating medium. The surface of the heat exchange block (5) is provided with a temperature sensor (12). A positioning frame (13) is installed below the cooling block and the heating block. The bottom of the positioning frame (13) is set as an opening and an elastic sealing film (14) is provided at the opening position. The positioning frame (13) is filled with thermally conductive silicone grease. Guide holes are provided between the cooling block, the heating block, the positioning frame (13) and the elastic sealing film (14) for the probe (7) to pass through.

5. The thick-film resistor TCR performance testing device according to claim 4, characterized in that, It also includes a connecting piece (17), one side of the positioning frame (13) is connected to an overflow pipe (15), one side of the heat exchange block (5) is connected to a U-shaped frame (16), the two ends of the connecting piece (17) are respectively equipped with a piston rod (18) and a movable rod (19), the piston rod (18) is slidably disposed in the overflow pipe (15), the movable rod (19) slides through the U-shaped frame (16) and the other end of the movable rod (19) is provided with a sliding plate (22), the movable rod (19) is sleeved with a second spring (20) on both sides respectively abutting between the sliding plate (22) and the wall of the U-shaped frame (16), the U-shaped frame (16) is provided with a U-shaped photoelectric sensor (21), and the sliding plate (22) can pass through the detection position of the U-shaped photoelectric sensor (21).

6. The thick-film resistor TCR performance testing device according to claim 5, characterized in that, The U-shaped photoelectric sensor (21) is provided in no less than two sets. After the elastic sealing film (14) is separated from the surface of the thick film resistor, the second spring (20) can drive the slider (22) to move to a position outside the two sets of U-shaped photoelectric sensors (21).

7. The thick-film resistor TCR performance testing device according to claim 4, characterized in that, The interior of the cooling block is divided into two cavities by a partition (25). The upper cavity is equipped with a labyrinth heat exchange plate (26) and a cooling gas is introduced into the upper cavity. The lower cavity is equipped with a coolant. The heat exchange block (5) is equipped with an insulation layer (27) on its outer side.

8. The thick-film resistor TCR performance testing device according to claim 7, characterized in that, The main air inlet pipe (28) connecting the upper cavity of the refrigeration block located downstream is also connected to a first air inlet pipe (29) and a second air inlet pipe (30). The first air inlet pipe (29) is used to access high-pressure cold air, and the second air inlet pipe (30) is connected to the exhaust port of another adjacent upstream refrigeration block. Both the first air inlet pipe (29) and the second air inlet pipe (30) are equipped with electromagnetic flow valves (31).

9. The thick film resistor TCR performance testing device according to claim 4, characterized in that, The heating block has an internal cavity filled with heat-conducting oil, and an electric heating tube (32) for heating the heat-conducting oil is provided inside the heating block.

10. The thick-film resistor TCR performance testing device according to claim 4, characterized in that, A return line (34) is also provided on one side of the test line (1), and a sorting device (35) is provided between the test line (1) and the return line (34). An air blowing assembly (33) is also provided on the test line (1) at the position between the cooling block and the heating block. The air blowing assembly (33) is used to blow air onto the thick film resistor sheet on the surface of the test line (1).

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