High-temperature test method and high-temperature test contact device for inductance product

Abstract

According to the high-temperature testing method for the inductance product, a new testing scheme is provided for testing the product performance of the inductance product in a high-temperature environment, and the problem that a normal-temperature testing clamp cannot enter the high-temperature environment to test the rated current of the product can be solved through the contact device; the temperature rise current and the saturation current are carried out in the same equipment, so that the equipment cost and the time cost are saved, and the equipment investment and the manufacturing investment are greatly reduced; meanwhile, in the testing process, through one-time calibration, when a plurality of testing leading-out ends are arranged on the PCB, continuous testing of multiple inductor products can be achieved, and the testing efficiency of the inductor products is effectively improved; in addition, through the design of the contact device, tight contact between the inductance product to be tested and the temperature detector is realized, and the test stability and the test precision can be effectively improved.

Description

Technical Field

[0001] The invention belongs to the technical field of capacitors and inductors, and in particular relates to a high-temperature testing method and a high-temperature testing contact device for an inductor product. Background Art

[0002] Chip inductors are widely used in the fields of communications, energy, automobile industry, medical and home appliances. Inductors pass direct current and block alternating current. They mainly play the role of filtering, oscillation, delay, and trapping in the circuit. In addition to the inductance and accuracy of the product, the rated current is also a very critical parameter in the application. It refers to the current of the product equipment when it is running at rated power under rated voltage. The maximum current value allowed to pass through the chip inductor during normal operation. If the operating current exceeds the rated current, it will burn out, which will cause equipment failure, electrical fire, explosion and other severe consequences, endangering human life and property safety.

[0003] The rated current includes the temperature rise current and the saturation current. The temperature rise current is defined as the current corresponding to the product temperature rising to a certain temperature when a certain current is applied to the inductor; the saturation current is the current corresponding to the change in the inductance of the inductor to a certain extent during the application of a variable current. For tests under normal temperature, the saturation current is usually tested on a conventional fixture using an impedance analyzer equipped with a bias current source, while the temperature rise current is tested using a bias current source, a test board, and an infrared tester.

[0004] As the application scenarios of electronic products in different fields become more and more extreme, more and more attention is paid to the performance of inductor products in extreme environments, and inductor manufacturers are required to test the rated current of inductor products under high temperatures. For manufacturers of inductor products, there are many difficulties in testing the saturation current and temperature rise current of products under high temperatures. First, in the product testing process, two currents require two sets of equipment and fixtures to complete, and the equipment cost is high; second, the test method of rated current at room temperature cannot be extended to high temperature, especially most test fixtures are not suitable for high temperature environments; third, the test cycle is long and inefficient; fourth, the stability and accuracy of the test are poor. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a high-temperature testing method and a high-temperature testing contact device for an inductor product, which can effectively solve the problems in the prior art that the testing equipment for current and temperature rise current is high in cost, the testing method for rated current at room temperature cannot be extended to high temperature, the testing cycle is long, the efficiency is low, and the stability and accuracy of the test are poor.

[0006] In order to solve the above technical problems, a technical solution adopted by the present invention is as follows:

[0007] A high temperature testing method for an inductor product comprises the following steps:

[0008] Step 1: Turn on the LCR bridge, bias current source and temperature monitor, solder the inductor product to be tested on the PCB board, and solder the test wires to the three lead terminals of the PCB board. Then install the PCB in the contact device in the constant temperature box and accurately contact the inductor product to be tested with the temperature sensor;

[0009] Step 2: Perform system calibration, remove the contact device, test line, PCB board and other equipment and interfering parasitic inductance. At room temperature, first perform open circuit calibration on the LCR bridge, then short-circuit the test line at both ends of the LCR bridge for short circuit calibration. After completion, re-place the test line at both ends of the LCR bridge to confirm the initial inductance and inductance value of the inductor product to be tested, and test the error range;

[0010] Step 3: Set a preset temperature for the thermostat, and monitor the temperature in the thermostat in real time through a temperature monitor until the preset value is reached;

[0011] Step 4: Obtain the inductance of the inductor product to be tested in real time through the LCR bridge;

[0012] Step 5: Set the AC test voltage amplitude, frequency and current step of the LCR bridge, start the current application switch on the bias current source, apply the bias current to the inductor under test, and monitor the surface temperature of the product after the current is applied at high temperature through the temperature monitor. By continuously increasing the current, when the surface temperature of the inductor product under test rises to a certain value, the temperature rise current is obtained;

[0013] Step 6: Gradually increase the current of the inductor product to be tested, and display the change of inductance of the inductor product to be tested under high temperature in real time on the LCR bridge when different currents are loaded. At this time, the inductance keeps decreasing. When the inductance drops to a certain value, the saturation current is obtained.

[0014] As a preferred embodiment of the present invention, a high temperature testing method for an inductor product further includes step 7: after the test is completed, the obtained data is saved and archived, and then the bias current source is first turned off, and then the constant temperature box, LCR bridge, and temperature monitor are turned off respectively.

[0015] As a preferred embodiment of the present invention, in step 3, the preset temperature is 85°C.

[0016] As a preferred embodiment of the present invention, step 5 and step 6 are performed in no particular order.

[0017] In order to solve the above technical problems, another technical solution adopted by the present invention is as follows:

[0018] A high temperature test contact device for an inductor product comprises a base, a pressure plate, a torsion spring, a fixing plate, a locking bolt and a temperature detector, wherein the pressure plate is rotatably connected to the base through the torsion spring, the torsion spring is arranged between the base and the pressure plate, one end of the torsion spring is fixedly connected to the base, and the other end of the torsion spring is fixedly connected to the pressure plate, the base is provided with a slot for placing a PCB board, the fixing plate is provided with a first threaded hole, the locking bolt is connected to the base through the threaded hole, the temperature detector is located between the fixing plate and the base, and the probe of the temperature detector is opposite to the slot.

[0019] As a preferred solution of the present invention, an avoidance notch is provided on a side of the pressing plate facing the slot.

[0020] As a preferred embodiment of the present invention, a high temperature test contact device for an inductor product further includes a locking plate, on which a second threaded hole is provided, the threaded hole being opposite to the first threaded hole, and the locking bolt passes through the first threaded hole and is connected to the second threaded hole.

[0021] As a preferred solution of the present invention, both the pressure plate and the base are provided with limiting slots, and the torsion spring abuts against the limiting slots.

[0022] As a preferred solution of the present invention, the contact device is configured to be made of high temperature resistant material.

[0023] The high temperature testing method and high temperature testing contact device of an inductor product provided by the present invention have the following beneficial effects compared with the prior art:

[0024] The present invention proposes a new test scheme for testing product performance of inductor products in a high temperature environment by building a set of high temperature test methods for inductor products, and through a contact device, the problem that a normal temperature test fixture cannot enter a high temperature environment to test the rated current of the product can be solved, and the temperature rise current and the saturation current can be tested on the same device, which saves equipment cost and time cost, and greatly reduces equipment investment and production investment; at the same time, during the test process, through one calibration, when multiple test lead terminals are set on a PCB circuit board, continuous testing of multiple inductor products can be achieved, and the test efficiency of the inductor products is effectively improved; in addition, through the design of the contact device, close contact between the inductor product to be tested and the temperature detector is achieved, and the test stability and test accuracy can be effectively improved; therefore, the present invention can solve the problem that a normal temperature test fixture cannot enter a high temperature to achieve the test of the temperature rise current and the saturation current on the same test system platform, effectively saving equipment cost, and the temperature rise current and the saturation current can be tested at the same time, thereby improving the test efficiency and achieving stable testing and higher test accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solution of the embodiment of the present invention, the drawings of the embodiment are briefly introduced below.

[0026] Figure 1 It is a structural schematic diagram of a high temperature test contact device for an inductor product provided by an embodiment of the present invention;

[0027] Figure 2 It is a structural schematic diagram of another view of a high temperature test contact device for an inductor product provided by an embodiment of the present invention.

[0028] Markings in the figure:

[0029] Base 1; pressure plate 2; torsion spring 3; fixing plate 4; locking bolt 5; temperature detector 6; slot 7; avoidance gap 8; locking plate 9; limiting notch 10. DETAILED DESCRIPTION

[0030] The specific implementation of the present invention is further described in detail below in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0031] In the description of the present invention, it should be understood that the terms "upper", "lower", "left", "right", "front", "back", "top", "bottom", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. It should be understood that the terms "first", "second", etc. are used in the present invention to describe various information, but such information should not be limited to these terms, which are only used to distinguish the same type of information from each other. For example, without departing from the scope of the present invention, "first" information may also be referred to as "second" information, and similarly, "second" information may also be referred to as "first" information.

[0032] A first preferred embodiment of the present invention provides a high temperature testing method for an inductor product, which comprises the following steps:

[0033] Step 1: Turn on the LCR bridge, bias current source and temperature monitor, solder the inductor product to be tested on the PCB board, and solder the test wires to the three lead terminals of the PCB board. Then install the PCB in the contact device in the constant temperature box and accurately contact the inductor product to be tested with the temperature sensor;

[0034] Step 2: Perform system calibration, remove the contact device, test line, PCB board and other equipment and interfering parasitic inductance. At room temperature, first perform open circuit calibration on the LCR bridge, then short-circuit the test line at both ends of the LCR bridge for short circuit calibration. After completion, re-place the test line at both ends of the LCR bridge to confirm the initial inductance and inductance value of the inductor product to be tested, and test the error range;

[0035] Step 3: Set a preset temperature for the thermostat, and monitor the temperature in the thermostat in real time through a temperature monitor until the preset value is reached;

[0036] Step 4: Obtain the inductance of the inductor product to be tested in real time through the LCR bridge;

[0037] Step 5: Set the AC test voltage amplitude, frequency and current step of the LCR bridge, start the current application switch on the bias current source, apply the bias current to the inductor under test, and monitor the surface temperature of the product after the current is applied at high temperature through the temperature monitor. By continuously increasing the current, when the surface temperature of the inductor product under test rises to a certain value, the temperature rise current is obtained; it should also be noted that in the normal temperature test environment, when the surface temperature of the inductor product under test rises by 40°C, the temperature rise current is obtained; and when the test environment temperature is 105°C, when the surface temperature of the inductor product under test rises to 20°C, the temperature rise current is obtained. In the specific test process, it is necessary to select a suitable temperature rise according to the environmental characteristics and product characteristics.

[0038] Step 6: gradually increase the current of the inductor product to be tested, and display the change of the inductance of the inductor product to be tested when different currents are loaded at high temperature in real time on the LCR bridge. At this time, the inductance continues to decrease. When the inductance decreases to a certain value, the saturation current is obtained. It should also be noted that in this embodiment, according to the product characteristics, the saturation current is obtained when the inductance decreases by 30%, 20% or 10%.

[0039] Exemplarily, a high temperature testing method for an inductor product also includes step 7: after the test is completed, the obtained data is saved and archived, and then the bias current source is first turned off, and then the constant temperature box, LCR bridge, and temperature monitor are turned off respectively.

[0040] Exemplarily, in step 3, the preset temperature is 85°C.

[0041] Exemplarily, step 5 and step 6 are performed in no particular order.

[0042] like Figure 1 to Figure 2As shown, a second preferred embodiment of the present invention provides a high-temperature test contact device for an inductor product, which includes a base 1, a pressure plate 2, a torsion spring 3, a fixing plate 4, a locking bolt 5 and a temperature detector 6. The pressure plate 2 is rotatably connected to the base 1 through the torsion spring 3, and the torsion spring 3 is arranged between the base 1 and the pressure plate 2. One end of the torsion spring 3 is fixedly connected to the base 1, and the other end of the torsion spring 3 is fixedly connected to the pressure plate 2. The base 1 is provided with a slot 7 for placing a PCB board, and the fixing plate 4 is provided with a first threaded hole. The locking bolt 5 is connected to the base 1 through the threaded hole, and the temperature detector 6 is located between the fixing plate 4 and the base 1, and the probe of the temperature detector 6 is opposite to the slot 7.

[0043] Exemplarily, a relief notch 8 is provided on a side of the pressing plate 2 facing the slot 7 .

[0044] Exemplarily, a high temperature test contact device for an inductor product further includes a locking plate 9, on which a second threaded hole is provided, the threaded hole being opposite to the first threaded hole, and the locking bolt 5 passes through the first threaded hole and is connected to the second threaded hole.

[0045] Exemplarily, both the pressure plate 2 and the base 1 are provided with a limiting slot 10 , and the torsion spring 3 abuts against the limiting slot 10 .

[0046] Exemplarily, the contact device is configured to be a high temperature resistant material.

[0047] The high temperature testing method of an inductor product of the present invention is compared with the traditional temperature rise current testing method and the traditional saturation current testing method. The results are shown in Table 1:

[0048]

[0049] Table 1

[0050] Accordingly, the present invention proposes a new testing scheme for testing the performance of inductor products in a high temperature environment by constructing a set of high temperature testing methods for inductor products, and through the contact device, it can solve the problem that the normal temperature test fixture cannot enter the high temperature environment to test the rated current of the product, and realize the temperature rise current and saturation current in the same device, saving equipment cost and time cost, and greatly reducing equipment investment and production investment; at the same time, during the test process, through one calibration, and when multiple test lead terminals are set on the PCB circuit board, continuous testing of multiple inductor products can be achieved, effectively improving the testing efficiency of the inductor products; in addition, through the design of the contact device, close contact between the inductor product to be tested and the temperature detector 6 is achieved, which can effectively improve the test stability and test accuracy; therefore, the present invention can solve the problem that the normal temperature test fixture cannot enter the high temperature to realize the test of temperature rise current and saturation current on the same test system platform, effectively saving equipment cost, and can test temperature rise current and saturation current at the same time, improve test efficiency, and achieve stable testing and higher test accuracy.

[0051] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0052] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and substitutions can be made without departing from the technical principles of the present invention. These improvements and substitutions should also be regarded as the scope of protection of the present invention.

Claims

1. A high temperature testing method for an inductor product, characterized in that: The following steps are involved: Step 1: Turn on the LCR bridge, bias current source and temperature monitor, solder the inductor product to be tested on the PCB board, and solder the test wires to the three lead terminals of the PCB board. Then install the PCB in the contact device in the constant temperature box and accurately contact the inductor product to be tested with the temperature sensor; Step 2: Perform system calibration, remove the contact device, test line, PCB board and other equipment and interfering parasitic inductance. At room temperature, first perform open circuit calibration on the LCR bridge, then short-circuit the test line at both ends of the LCR bridge for short circuit calibration. After completion, re-place the test line at both ends of the LCR bridge to confirm the initial inductance and inductance value of the inductor product to be tested, and test the error range; Step 3: Set a preset temperature for the thermostat, and monitor the temperature in the thermostat in real time through a temperature monitor until the preset value is reached; Step 4: Obtain the inductance of the inductor product to be tested in real time through the LCR bridge; Step 5: Set the AC test voltage amplitude, frequency and current step of the LCR bridge, start the current application switch on the bias current source, apply the bias current to the inductor under test, and monitor the surface temperature of the product after the current is applied at high temperature through the temperature monitor. By continuously increasing the current, when the surface temperature of the inductor product under test rises to a certain value, the temperature rise current is obtained; Step 6: Gradually increase the current of the inductor product to be tested, and display the change of inductance of the inductor product to be tested under high temperature in real time on the LCR bridge when different currents are loaded. At this time, the inductance keeps decreasing. When the inductance drops to a certain value, the saturation current is obtained.

2. A high temperature testing method for an inductor product according to claim 1, characterized in that: The method further includes step 7: after the test is completed, the obtained data is saved and archived, and then the bias current source is first turned off, and then the constant temperature box, the LCR bridge, and the temperature monitor are turned off respectively.

3. The high temperature testing method for an inductor product according to claim 1, characterized in that: In step 3, the preset temperature is 85°C.

4. The high temperature testing method for an inductor product according to claim 1, characterized in that: Steps 5 and 6 are performed in no particular order.

5. A high temperature test contact device for an inductor product, characterized in that: It includes a base, a pressure plate, a torsion spring, a fixing plate, a locking bolt and a temperature detector, wherein the pressure plate is rotatably connected to the base through the torsion spring, the torsion spring is arranged between the base and the pressure plate, one end of the torsion spring is fixedly connected to the base, and the other end of the torsion spring is fixedly connected to the pressure plate, the base is provided with a slot for placing a PCB board, the fixing plate is provided with a first threaded hole, the locking bolt passes through the threaded hole and is connected to the base, the temperature detector is located between the fixing plate and the base, and the probe of the temperature detector is opposite to the slot.

6. A high temperature test contact device for an inductor product according to claim 5, characterized in that: A relief notch is provided on a side of the pressing plate facing the slot.

7. A high temperature test contact device for an inductor product according to claim 5, characterized in that: It also includes a locking plate, on which a second threaded hole is provided, the threaded hole is opposite to the first threaded hole, and the locking bolt passes through the first threaded hole and is connected to the second threaded hole.

8. The high temperature test contact device for inductor products according to claim 5, characterized in that: The pressure plate and the base are both provided with limiting notches, and the torsion spring abuts against the limiting notches.

9. A high temperature test contact device for an inductor product according to claim 5, characterized in that: The contact device is made of high temperature resistant material.

Images