Zener diode aging test circuit and method

Abstract

The invention provides a voltage stabilizing diode aging test circuit and method, and relates to the technical field of aging tests, and the circuit comprises a first power supply, a second power supply, a processing unit, a plurality of to-be-tested voltage stabilizing diodes, a heating sheet, and a first voltage detection unit. The plurality of to-be-tested voltage stabilizing diodes are connected in series and then are connected in parallel with the first power supply and the second power supply. A heating sheet is fixed on each to-be-detected voltage stabilizing diode, and each to-be-detected voltage stabilizing diode is connected in parallel with a first voltage detection unit. The input end of the processing unit is connected with the multiple first voltage detection units, and the output end of the processing unit is connected with the multiple heating pieces. And the processing unit is used for calculating the actual junction temperature of each to-be-measured voltage-stabilizing diode according to each actual voltage-stabilizing voltage and controlling the working state of each heating sheet according to each actual junction temperature when the junction temperature calibration is carried out on the plurality of to-be-measured voltage-stabilizing diodes, so that the actual junction temperature of each to-be-measured voltage-stabilizing diode is stabilized to the target junction temperature.

Description

Technical Field

[0001] The present application relates to the technical field of aging test, and in particular to a circuit and method for aging test of a voltage regulator diode. Background Art

[0002] In order to evaluate the performance and life of Zener diodes in practical applications, it is necessary to perform an aging test on the Zener diodes to improve their reliability and service life. At present, the method for performing an aging test on multiple Zener diodes is: F The relationship between the junction temperature and the test environment temperature is controlled by a high temperature box, so that the junction temperature of multiple Zener diodes under test reaches the rated maximum junction temperature while the rated current is passed.

[0003] Measuring V F The required current is output through the pulse current generator. F During the measurement, the impact on the test process is minimized, which requires the pulse current generator to have an extremely fast response speed, that is, the current output by the pulse current generator needs to have an extremely high rise and fall slope. At the same time, the V F The test is performed at a low current (usually 10mA). Since the current is small, the pulse current generator requires higher performance accuracy, resulting in higher costs. In addition, since V F Small, usually in the mV level, V at different temperatures F The change of V F The sampling device also requires higher performance accuracy, further increasing the cost.

[0004] In addition, due to the differences between multiple individual Zener diodes to be tested and the temperature fluctuations, uniformity and deviations inside the high-temperature test chamber, when the same batch of Zener diodes to be tested are in the same test environment temperature and the same test current is applied, it is impossible to ensure that the junction temperature of all Zener diodes to be tested is the target junction temperature required by the test, which ultimately leads to inaccurate aging test results.

[0005] In summary, how to improve the accuracy of the Zener diode aging test and reduce the test cost is a technical problem that needs to be solved urgently by technical personnel in this field. Summary of the invention

[0006] The purpose of the present application is to provide a Zener diode aging test circuit and method to improve the accuracy of the Zener diode aging test and reduce the test cost.

[0007] In order to achieve the above purpose, the technical solution adopted in this application is as follows:

[0008] On the one hand, the present application provides a voltage regulator diode aging test circuit, comprising: a first power supply and at least one test module, wherein the test module comprises a second power supply, a processing unit, and a plurality of equal numbers of voltage regulator diodes to be tested, a heating plate, and a first voltage detection unit;

[0009] A plurality of the voltage stabilizing diodes to be tested are connected in series and then respectively connected in parallel with the first power supply and the second power supply; wherein the first power supply is used to output an aging test current, and the second power supply is used to output a junction temperature test current;

[0010] A heating plate is fixed on each of the voltage-stabilizing diodes to be tested, and a first voltage detection unit is connected in parallel to each of the voltage-stabilizing diodes to be tested; the input end of the processing unit is respectively connected to a plurality of the first voltage detection units, and the output end of the processing unit is respectively connected to a plurality of the heating plates;

[0011] When performing junction temperature calibration on multiple Zener diodes to be tested, multiple first voltage detection units are used to detect the current actual Zener voltages of multiple Zener diodes to be tested; the processing unit is used to calculate the actual junction temperature of each Zener diode to be tested according to each actual Zener voltage, and control the working state of each heating plate according to each actual junction temperature, so that the actual junction temperature of each Zener diode to be tested is stabilized to the target junction temperature.

[0012] Further, the test module also includes a first switch and a second switch; one end of the first power supply is connected to one end of the plurality of voltage-stabilizing diodes to be tested in series through the first switch, and the other end of the first power supply is connected to the other end of the plurality of voltage-stabilizing diodes to be tested in series; one end of the second power supply is connected to one end of the plurality of voltage-stabilizing diodes to be tested in series through the second switch, and the other end of the second power supply is connected to the other end of the plurality of voltage-stabilizing diodes to be tested in series;

[0013] When performing an aging test on the plurality of Zener diodes to be tested, the first switch is closed and the second switch is opened, so that the first power supply outputs an aging test current to the plurality of Zener diodes to be tested;

[0014] When performing junction temperature calibration on the plurality of Zener diodes to be tested, the first switch is opened and the second switch is closed, so that the second power supply outputs a junction temperature test current to the plurality of Zener diodes to be tested.

[0015] Furthermore, the Zener diode aging test circuit also includes a high-temperature test box, and the plurality of Zener diodes to be tested are placed in the high-temperature test box, and the high-temperature test box is used to increase the test environment temperature and maintain it at a first junction temperature; wherein the first junction temperature is lower than the target junction temperature.

[0016] Further, the processing unit includes a collection unit, a calculation unit and a control unit; the input end of the collection unit is respectively connected to the plurality of first voltage detection units, the output end of the collection unit is connected to the input end of the calculation unit, the output end of the calculation unit is connected to the input end of the control unit, and the output end of the control unit is respectively connected to the plurality of heating plates;

[0017] The acquisition unit is used to acquire a plurality of actual regulated voltages detected by the first voltage detection unit, and send the plurality of actual regulated voltages to the calculation unit;

[0018] The calculation unit is used to calculate the actual junction temperature of each of the zener diodes to be tested according to each of the actual regulated voltages, and compare each of the actual junction temperatures with the target junction temperature; if the actual junction temperature is lower than the target junction temperature, the calculation unit sends a first instruction to the control unit; if the actual junction temperature is higher than or equal to the target junction temperature, the calculation unit sends a second instruction to the control unit;

[0019] The control unit is used to control the heating plate to increase the temperature when receiving the first instruction; the control unit is also used to control the heating plate to stop heating when receiving the second instruction.

[0020] Furthermore, the test module also includes an electronic load, one end of which is connected to the first power supply, and the other end of which is connected to one end of a plurality of the voltage-stabilizing diodes to be tested connected in series; the electronic load is used to adjust the magnitude of the aging test current output by the first power supply.

[0021] Furthermore, the test module also includes a current detection unit, a second voltage detection unit and an alarm unit;

[0022] One end of the current detection unit is connected to the first power supply, and the other end of the current detection unit is connected to one end of a plurality of the voltage-stabilizing diodes to be tested connected in series;

[0023] The second voltage detection unit is connected in parallel to two ends of a plurality of the voltage zener diodes to be tested connected in series;

[0024] The alarm unit is connected to the current detection unit and the second voltage detection unit respectively, and is used to alarm when the data detected by the current detection unit or the second voltage detection unit is abnormal.

[0025] On the other hand, the present application further provides a Zener diode aging test method, which is applied to a processing unit in a Zener diode aging test circuit as described in any one of the aforementioned implementations, and the method includes:

[0026] Obtaining the actual current regulated voltage of each of the zener diodes to be tested;

[0027] Calculate the actual junction temperature of each of the voltage regulator diodes to be tested according to each of the actual voltage regulator voltages;

[0028] The working state of each of the heating plates is controlled respectively according to each of the actual junction temperatures, so that the actual junction temperature of each of the voltage regulator diodes to be tested is stabilized to the target junction temperature.

[0029] Furthermore, the step of calculating the actual junction temperature of each of the zener diodes to be tested according to each of the actual regulated voltages comprises:

[0030] Obtaining the regulated voltage corresponding to the zener diode to be tested under a plurality of different test environment temperatures;

[0031] Calculating a plurality of Z coefficients according to the plurality of test environment temperatures and the plurality of regulated voltages;

[0032] When the actual regulated voltage is less than the minimum regulated voltage, the actual junction temperature of the zener diode to be tested is:

[0033] T j =T A1 -(V Z1 -V Zx ) / Z1

[0034] Among them, V Z1 is the minimum regulated voltage among multiple regulated voltages, T A1 is the test environment temperature corresponding to the minimum regulated voltage, Z1 is the Z coefficient corresponding to the minimum regulated voltage; V Zx is the actual voltage regulator voltage of the Zener diode to be tested, T j is the actual junction temperature of the Zener diode to be tested;

[0035] When the actual regulated voltage is equal to the minimum regulated voltage, the actual junction temperature of the zener diode to be tested is: T j =T A1 ;

[0036] When the actual regulated voltage is greater than the minimum regulated voltage and less than the maximum regulated voltage, the actual junction temperature of the zener diode to be tested is:

[0037] T j =T Ak +(V Zx -V Zk ) / Zk

[0038] Among them, 1 <k<n,V Zk For multiple regulated voltages with VZx The difference between the minimum regulated voltage and V Zk <V Zx ; T Ak V Zk The corresponding test environment temperature, Zk is V Zk The corresponding Z coefficient;

[0039] When the actual regulated voltage is equal to the maximum regulated voltage, the actual junction temperature of the zener diode to be tested is: T j =T An ; Among them, T An is the test environment temperature corresponding to the maximum regulated voltage;

[0040] When the actual regulated voltage is greater than the maximum regulated voltage, the actual junction temperature of the zener diode to be tested is:

[0041] T j =T An +(V Zx -V Zn ) / Z(n-1)

[0042] Among them, V Zn is the maximum regulated voltage among multiple regulated voltages, T An is the test environment temperature corresponding to the maximum regulated voltage, and Z(n-1) is the Z coefficient corresponding to the regulated voltage with the smallest difference from the maximum regulated voltage among multiple regulated voltages.

[0043] Furthermore, the Z coefficient is obtained according to the following formula:

[0044] Zm=[V Z(m+1) -V Zm ] / [T A(m+1) -T Am ]

[0045] Where Zm is the Z coefficient, and 1≤m≤n, T Am is the test environment temperature corresponding to Zm among multiple test environment temperatures, T A(m+1) For multiple test environment temperatures and T Am The test environment temperature with the smallest difference, and T A(m+1) >T Am ; V Zm is the regulated voltage corresponding to Zm among multiple regulated voltages, V Z(m+1) For multiple regulated voltages with V Zm The difference between the minimum regulated voltage and V Z(m+1) >V Zm .

[0046] Furthermore, the step of controlling the working state of each of the heating plates according to each of the actual junction temperatures so that the actual junction temperature of each of the voltage regulator diodes to be tested is stabilized to a target junction temperature includes:

[0047] comparing the actual junction temperature with the target junction temperature;

[0048] If the actual junction temperature is lower than the target junction temperature, controlling the heating plate to increase the temperature;

[0049] If the actual junction temperature is higher than or equal to the target junction temperature, the heating plate is controlled to stop heating.

[0050] Compared with the prior art, this application has the following beneficial effects:

[0051] The present application provides a Zener diode aging test circuit and method. Since a heating plate is fixed on each Zener diode to be tested, and each Zener diode to be tested is connected in parallel with a first voltage detection unit, the processing unit can calculate the actual junction temperature according to the stabilizing voltage detected by the first voltage detection unit, and perform PID closed-loop control on the output of the heating plate according to the actual junction temperature. The junction temperature of each Zener diode to be tested can be individually and accurately controlled to ensure that the actual junction temperature of each Zener diode to be tested is stabilized at the target junction temperature required by the test, thereby improving the accuracy of the Zener diode aging test.

[0052] Furthermore, since the present application uses the zener voltage value of the zener diode for junction temperature calibration, the zener voltage is several orders of magnitude higher than the forward voltage used for conventional junction temperature calibration. Therefore, the performance accuracy of the second power supply for outputting the junction temperature test current and the first voltage detection unit for collecting the actual zener voltage of the zener diode to be tested do not need to be particularly precise. Under normal circumstances, a voltmeter of the ordinary multimeter grade can be used for the first voltage detection unit, which greatly reduces the test cost. In addition, by connecting multiple zener diodes to be tested in series for testing, only one electronic load can be used for current regulation, reducing the number of electronic loads used, thereby further reducing the test cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all of the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the application claimed for protection, but merely represents the selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians of the art without making creative work are within the scope of protection of the present application.

[0054] Figure 1 One of the structural schematic diagrams of a voltage regulator diode aging test circuit provided in this application;

[0055] Figure 2 One of the structural schematic diagrams of fixing a voltage stabilizing diode to be tested and a heating plate provided in the present application;

[0056] Figure 3 The second structural diagram of a voltage stabilizing diode to be tested and a heating plate provided in the present application;

[0057] Figure 4 The second structural diagram of a voltage regulator diode aging test circuit provided in this application;

[0058] Figure 5 The third structural diagram of a voltage regulator diode aging test circuit provided in this application;

[0059] Figure 6 The fourth structural diagram of a voltage regulator diode aging test circuit provided in this application;

[0060] Figure 7 A schematic diagram of a process flow of a voltage regulator diode aging test method provided in this application;

[0061] Figure 8 It is a schematic diagram of the sub-steps of step S200 in this application;

[0062] Fig. 9 A curve diagram of the relationship between the regulated voltage and the test environment temperature provided in this application;

[0063] Fig.10 It is a schematic diagram of the sub-steps of step S300 in this application.

[0064] Figure numerals: 10-voltage-stabilizing diode aging test circuit; 20-PCB test carrier; 100-first power supply; 200-test module; 210-second power supply; 220-processing unit; 221-collection unit; 222-calculation unit; 223-control unit; 230-voltage-stabilizing diode to be tested; 240-heating plate; 250-first voltage detection unit; 260-high temperature test chamber; 270-current detection unit; 280-second voltage detection unit; 290-alarm unit; SW1-first switch; SW2-second switch; E L -Electronic load; R L -Current limiting resistor; FUSE-fuse. DETAILED DESCRIPTION

[0065] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the application claimed for protection, but merely represents the selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without making creative work belong to the scope of protection of the present application.

[0066] In the description of this application, it should be noted that relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. The term "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 directly connected or indirectly connected through an intermediate medium.

[0067] In conjunction with the accompanying drawings, some embodiments of the present application are described in detail below. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0068] As mentioned in the background technology, the junction temperature calibration currently available on the market generally adopts the forward voltage method, which has high performance accuracy requirements for the pulse current generator and the voltage sampling device, increasing the test cost. In addition, the prior art uses a high-temperature test chamber to uniformly heat the junction temperature of multiple devices under test for aging testing. Due to the differences between the individual Zener diodes under test and the temperature fluctuations, uniformity, and deviations inside the high-temperature test chamber, when the same batch of Zener diodes under test are in the same test environment temperature and the same test current is applied, it is impossible to ensure that the junction temperature of all Zener diodes under test is the target junction temperature required by the test, which ultimately leads to inaccurate aging test results.

[0069] Therefore, how to improve the accuracy of the zener diode aging test and reduce the test cost is a technical problem that needs to be solved urgently by those skilled in the art.

[0070] To solve the above technical problems, please refer to Figure 1 The embodiment of the present application provides a Zener diode aging test circuit 10, comprising: a first power supply 100 and at least one test module 200. The test module 200 comprises: a second power supply 210, a processing unit 220, and a plurality of Zener diodes 230 to be tested, a heating plate 240, and a first voltage detection unit 250 of equal number.

[0071] After being connected in series, multiple Zener diodes 230 to be tested are respectively connected in parallel with the first power supply 100 and the second power supply 210. The first power supply 100 is used to output an aging test current when the multiple Zener diodes 230 to be tested are subjected to an aging test, and its current value is generally 1mA to 200mA. The second power supply 210 is used to output a junction temperature test current when the multiple Zener diodes 230 to be tested are subjected to a junction temperature calibration, and its current value is generally 1mA to 10mA.

[0072] A heating plate 240 is fixed on each Zener diode 230 to be tested, and each Zener diode 230 to be tested is connected in parallel with a first voltage detection unit 250. The input end of the processing unit 220 is respectively connected to the plurality of first voltage detection units 250, and the output end of the processing unit 220 is respectively connected to the plurality of heating plates 240.

[0073] As an optional implementation, the heating plate 240 can be a metal ceramic heater (Metal Ceramic Heater, MCH). The fixing method of the heating plate 240 and the voltage regulator diode 230 to be tested can be found in Figure 2 and Figure 3 For the voltage regulator diode 230 to be tested which has its own screw locking hole, such as Figure 2 As shown, the heating plate 240 can be directly locked on the voltage regulator diode 230 to be tested. For the voltage regulator diode 230 to be tested without a screw locking hole, as shown in FIG. Figure 3As shown, the Zener diode 230 to be tested can be welded on the PCB test carrier 20, and then the heating plate 240 can be fixed on the PCB test carrier 20, or the heating plate 240 and the Zener diode 230 to be tested can be fixed by other methods to heat the Zener diode 230 to be tested.

[0074] When the junction temperature of the plurality of Zener diodes 230 to be tested is calibrated, the second power supply 210 outputs a junction temperature test current to the plurality of Zener diodes 230 to be tested, and the plurality of first voltage detection units 250 detect the actual current Zener voltages of the plurality of Zener diodes 230 to be tested. The processing unit 220 calculates the actual junction temperature of each Zener diode 230 to be tested according to each actual Zener voltage, and controls the working state of each heating plate 240 according to each actual junction temperature, so that the actual junction temperature of each Zener diode 230 to be tested is stabilized to the target junction temperature.

[0075] Based on the above design, the embodiment of the present application adopts the stabilizing voltage value of the zener diode for junction temperature calibration. Since the stabilizing voltage V of the commonly used zener diode is Z Generally, it is 3V to 100V, and the forward voltage V F Generally, it is 0.6V to 0.7V. That is, the regulated voltage V Z Compared with the forward voltage V used in conventional junction temperature calibration F Therefore, the performance accuracy of the second power supply 210 for outputting the junction temperature test current and the first voltage detection unit 250 for collecting the actual regulated voltage of the zener diode 230 to be tested does not need to be particularly accurate. Under normal circumstances, the first voltage detection unit 250 can be competent with a common multimeter-level voltmeter, which greatly reduces the test cost.

[0076] Furthermore, since a heating plate 240 is fixed on each Zener diode 230 to be tested, and a first voltage detection unit 250 is connected in parallel to each Zener diode 230 to be tested, the processing unit 220 can calculate the actual junction temperature according to the regulated voltage detected by the first voltage detection unit 250, and perform PID closed-loop control on the output of the heating plate 240 according to the actual junction temperature. The junction temperature of each Zener diode 230 to be tested can be individually and accurately controlled to ensure that the actual junction temperature of each Zener diode 230 to be tested is stabilized at the target junction temperature required by the test, thereby improving the accuracy of the Zener diode aging test.

[0077] To better understand the working principle of Zener diode aging test circuit 10, please refer to Figure 4In the embodiment of the present application, the test module 200 further includes a first switch SW1 and a second switch SW2. One end of the first power supply 100 is connected to one end of a plurality of voltage-stabilizing diodes 230 to be tested in series through the first switch SW1, and the other end of the first power supply 100 is connected to the other end of a plurality of voltage-stabilizing diodes 230 to be tested in series. One end of the second power supply 210 is connected to one end of a plurality of voltage-stabilizing diodes 230 to be tested in series through the second switch SW2, and the other end of the second power supply 210 is connected to the other end of a plurality of voltage-stabilizing diodes 230 to be tested in series.

[0078] When performing an aging test on the plurality of Zener diodes 230 to be tested, the first switch SW1 is closed and the second switch SW2 is opened, so that the first power supply 100 outputs an aging test current to the plurality of Zener diodes 230 to be tested.

[0079] When the junction temperature of the plurality of Zener diodes 230 to be tested is calibrated, the first switch SW1 is opened and the second switch SW2 is closed, so that the second power supply 210 outputs a junction temperature test current to the plurality of Zener diodes 230 to be tested.

[0080] In a feasible implementation, the Zener diode aging test circuit 10 further includes a high temperature test box 260, and the plurality of Zener diodes 230 to be tested are placed in the high temperature test box 260. The high temperature test box 260 is used to increase the test environment temperature and maintain it at a first junction temperature, wherein the first junction temperature is lower than the target junction temperature.

[0081] Optionally, the first junction temperature is 5° C. to 15° C. lower than the target junction temperature. For example, if the target junction temperature required by the test is 150° C., the high temperature test chamber 260 increases the test environment temperature and maintains it at 135° C. to 145° C.

[0082] Based on the above design, the working principle of the Zener diode aging test circuit 10 is as follows: first, close the first switch SW1 and disconnect the second switch SW2, so that the first power supply 100 outputs an aging test current to the multiple Zener diodes 230 to be tested. The high temperature test box 260 stops heating after raising the test environment temperature to the first junction temperature, and maintains the current test environment temperature. When it is necessary to perform junction temperature calibration on multiple Zener diodes 230 to be tested, disconnect the first switch SW1 and close the second switch SW2, so that the second power supply 210 outputs a junction temperature test current to the multiple Zener diodes 230 to be tested. The processing unit 220 calculates the actual junction temperature of each Zener diode 230 to be tested according to the actual regulated voltage detected by the multiple first voltage detection units 250, and controls the working state of each heating plate 240 according to each actual junction temperature, so that the actual junction temperature of each Zener diode 230 to be tested is stabilized to the target junction temperature. After the junction temperature calibration is completed, close the first switch SW1 again, disconnect the second switch SW2, and continue the aging test.

[0083] Further, in the embodiment of the present application, the processing unit 220 includes a collection unit 221, a calculation unit 222 and a control unit 223. The input end of the collection unit 221 is respectively connected to the plurality of first voltage detection units 250, the output end of the collection unit 221 is connected to the input end of the calculation unit 222, the output end of the calculation unit 222 is connected to the input end of the control unit 223, and the output end of the control unit 223 is respectively connected to the plurality of heating plates 240.

[0084] The acquisition unit 221 is used to acquire the actual regulated voltages detected by the plurality of first voltage detection units 250 , and send the plurality of actual regulated voltages to the calculation unit 222 .

[0085] The calculation unit 222 is used to calculate the actual junction temperature of each zener diode 230 to be tested according to each actual regulated voltage, and compare each actual junction temperature with the target junction temperature. If the actual junction temperature is lower than the target junction temperature, the calculation unit 222 sends a first instruction to the control unit 223. If the actual junction temperature is higher than or equal to the target junction temperature, the calculation unit 222 sends a second instruction to the control unit 223.

[0086] The control unit 223 is used to control the heating plate 240 to heat up when receiving the first instruction, and the heat is transferred to the Zener diode 230 to be tested through direct contact or the PCB test carrier 20, thereby increasing the actual junction temperature of the Zener diode 230 to be tested. The control unit 223 is also used to control the heating plate 240 to stop heating when receiving the second instruction.

[0087] The present application adopts a PID closed-loop control heating method, which adjusts the test environment temperature through a high-temperature test chamber 260 and coordinates the heating treatment of each heating plate 240, ensuring that the actual junction temperature of each Zener diode 230 to be tested can be stabilized to the target junction temperature, thereby improving the accuracy of the Zener diode aging test.

[0088] In addition, in order to adjust the magnitude of the aging test current output by the first power supply 100, refer to Figure 5 In the embodiment of the present application, the test module 200 also includes an electronic load E L Among them, the electronic load E L One end of the electronic load E is connected to the first power supply 100. L The other end of is connected to one end of a plurality of voltage regulator diodes 230 to be tested connected in series.

[0089] Compared with the prior art, each Zener diode 230 to be tested is equipped with an electronic load E L The current regulation method causes the electronic load E LIn the case of a large number of devices, high cost, and large size of the whole machine, the present application connects multiple voltage regulator diodes 230 to be tested in series, and only one electronic load E is needed. L For example, four voltage regulator diodes 230 to be tested are connected in series and then an electronic load E is used. L To adjust the current, the electronic load E L The equipment requirements are only 1 / 4 of the existing technology, which can greatly reduce costs and effectively reduce equipment size.

[0090] Furthermore, in the embodiment of the present application, the test module 200 also includes a current limiting resistor R L And fuse FUSE. Considering that the first power supply 100 with different performance has different response speeds in current limiting, when extreme situations such as test failure occur, the fuse FUSE can be quickly blown to perform overcurrent protection. Among them, the current specification of the fuse FUSE can be selected according to the actual aging test current.

[0091] As an optional implementation, the test module 200 further includes a current detection unit 270, a second voltage detection unit 280 and an alarm unit 290. One end of the current detection unit 270 is connected to the first power supply 100, and the other end of the current detection unit 270 is connected to one end of a plurality of voltage-stabilizing diodes 230 to be tested connected in series. The second voltage detection unit 280 is connected in parallel to both ends of a plurality of voltage-stabilizing diodes 230 to be tested connected in series. Optionally, the current detection unit 270 may be an ammeter, and the second voltage detection unit 280 may be a voltmeter.

[0092] The alarm unit 290 is connected to the current detection unit 270 and the second voltage detection unit 280 respectively, and is used to alarm when the data detected by the current detection unit 270 or the second voltage detection unit 280 is abnormal. Optionally, the alarm unit 290 may be an audible and visual alarm.

[0093] The above is the working principle of a test module 200. In order to implement the aging test of more Zener diodes 230 to be tested at the same time, please refer to Figure 6 , multiple test modules 200 can be connected in parallel with the first power supply 100 according to the requirements. The total number of the voltage regulator diodes 230 to be tested is determined by the total capacity of the first power supply 100.

[0094] For further information, see Figure 7 The present application also provides a method for testing aging of a voltage regulator diode, which is applied to a processing unit in a voltage regulator diode aging test circuit according to any one of the above embodiments. The method comprises the following steps:

[0095] Step S100: obtaining the actual current regulated voltage of each zener diode to be tested.

[0096] In the embodiment of the present application, when the junction temperature of a plurality of Zener diodes to be tested is calibrated, the processing unit can respectively obtain the current actual regulated voltage of each Zener diode to be tested through a plurality of first detection units.

[0097] Step S200: Calculate the actual junction temperature of each zener diode to be tested according to each actual zener voltage.

[0098] See also Figure 8 In the embodiment of the present application, step S200 of calculating the actual junction temperature of each zener diode to be tested according to each actual zener voltage includes sub-steps S210 to S270.

[0099] Step S210: obtaining the regulated voltage corresponding to the zener diode to be tested under a plurality of different test environment temperatures.

[0100] Step S220: Calculate and obtain multiple Z coefficients according to multiple test environment temperatures and multiple regulated voltages.

[0101] It should be noted that under a given constant current, the regulated voltage of the Zener diode is dependent on the junction temperature. The regulated voltage is a one-time function of the junction temperature, and its slope is called the Z coefficient. The purpose of measuring the Z coefficient is to find the corresponding relationship between the temperature regulated voltage and the junction temperature. That is, after the Z coefficient is measured, the regulated voltage value at any junction temperature can be obtained, and similarly, the junction temperature value corresponding to any regulated voltage value can also be obtained.

[0102] In the embodiment of the present application, in order to calculate the actual junction temperature according to the actual regulated voltage of the Zener diode to be tested, it is first necessary to adjust the test environment temperature multiple times through the high temperature test chamber to obtain the regulated voltage corresponding to the Zener diode to be tested under multiple different test environment temperatures. At this time, the Zener diode to be tested is not loaded (that is, it does not heat itself), and when the test environment temperature is balanced for a long enough time, it can be considered that the junction temperature T of the Zener diode to be tested is j The test environment temperature T A equal.

[0103] For example, see Fig. 9 , assuming that the processing unit obtains the voltage regulator diode under test at 5 different test environment temperatures (i.e., T A1 、T A2 、T A3 、T A4 、T A5 ) corresponds to the regulated voltages V Z1 、V Z2 、V Z3 、V Z4 、V Z5Then, according to the five test environment temperatures and five regulated voltages, four Z coefficients (i.e., Z1, Z2, Z3, and Z4) can be calculated respectively.

[0104] In the embodiment of the present application, the calculation formula of the Z coefficient is as follows:

[0105] Zm=ΔV Z / ΔV A =[V Z(m+1) -V Zm ] / [T A(m+1) -T Am ].

[0106] Where Zm is the Z coefficient, and 1≤m≤n. Am is the test environment temperature corresponding to Zm among multiple test environment temperatures, T A(m+1) For multiple test environment temperatures and T Am The test environment temperature with the smallest difference, and T A(m+1) >T Am . V Zm is the regulated voltage corresponding to Zm among multiple regulated voltages, V Z(m+1) For multiple regulated voltages with V Zm The difference between the minimum regulated voltage and V Z(m+1) >V Zm .

[0107] Combination Fig. 9 , taking 5 test environment temperatures and 5 regulated voltages as examples, the 4 Z coefficients can be calculated according to the above formula:

[0108] Z1=(V Z2 -V Z1 ) / (T A2 -T A1 );

[0109] Z2=(V Z3 -V Z2 ) / (T a3 -T A2 );

[0110] Z3=(V Z4 -V Z3 ) / (T A4 -T A3 );

[0111] Z4=(V Z5 -V Z4 ) / (T A5 -T A4 ).

[0112] Step S230: When the actual regulated voltage is less than the minimum regulated voltage, the actual junction temperature of the zener diode to be tested is: T j =T A1 -(V Z1 -V Zx ) / Z1.

[0113] Among them, V Z1 is the minimum regulated voltage among multiple regulated voltages, T A1 is the test environment temperature corresponding to the minimum regulated voltage, and Z1 is the Z coefficient corresponding to the minimum regulated voltage. Zx is the actual voltage regulator voltage of the Zener diode to be tested, T j is the actual junction temperature of the Zener diode to be tested.

[0114] Step S240: When the actual regulated voltage is equal to the minimum regulated voltage, the actual junction temperature of the zener diode to be tested is: T j =T A1 .

[0115] Step S250: When the actual regulated voltage is greater than the minimum regulated voltage and less than the maximum regulated voltage, the actual junction temperature of the zener diode to be tested is: T j =T Ak +(V Zx -V Zk ) / Zk.

[0116] Among them, 1 <k<n,V Zk For multiple regulated voltages with V Zx The difference between the minimum regulated voltage and V Zk <V Zx . T Ak V Zk The corresponding test environment temperature, Zk is V Zk The corresponding Z coefficient.

[0117] Step S260: When the actual regulated voltage is equal to the maximum regulated voltage, the actual junction temperature of the zener diode to be tested is: T j =T An Among them, T An is the test environment temperature corresponding to the maximum regulated voltage.

[0118] Step S270: When the actual regulated voltage is greater than the maximum regulated voltage, the actual junction temperature of the zener diode to be tested is: T j =T An +(V Zx -V Zn ) / Z(n-1).

[0119] Among them, V Zn is the maximum regulated voltage among multiple regulated voltages, TAn is the test environment temperature corresponding to the maximum regulated voltage. Z(n-1) is the Z coefficient corresponding to the regulated voltage with the smallest difference from the maximum regulated voltage among the multiple regulated voltages.

[0120] Combination Fig. 9 , taking 5 test environment temperatures and 5 regulated voltages as an example, assuming that the actual regulated voltage V Z V Zx According to the above method, the corresponding actual junction temperature T j for:

[0121] When V Zx <V Z1 When T j =T A1 -(V Z1 -V Zx ) / Z1;

[0122] When V Z1 <V Zx <V Z2 When T j =T A1 +(V Zx -V Z1 ) / Z1;

[0123] When V Z2 <V Zx <V Z3 When T j =T A2 +(V Zx -V Z2 ) / Z2;

[0124] When V Z3 <V Zx <V Z4 When T j =T A3 +(V Zx -V Z3 ) / Z3;

[0125] When V Z4 <V Zx <V Z5 When T j =T A4 +(V Zx -V Z4 ) / Z4;

[0126] When V Z5 <V Zx When T j =T A4 +(V Zx -V Z5 ) / Z4.

[0127] For example, the test environment temperature T is measured according to the above method. A When the temperature is 50 / 75 / 100 / 125 / 150℃ respectively, the corresponding regulated voltage V Z They are 31.65 / 32.331 / 33.017 / 33.644 / 34.293V respectively, then △T A 25 / 25 / 25 / 25℃, △V Z are 0.681 / 0.686 / 0.627 / 0.649V, Z1 / Z2 / Z3 / Z4 are 0.02724 / 0.02744 / 0.02508 / 0.02596 respectively. When the actual regulated voltage V Zx =32.685V, according to the above method, the actual junction temperature is calculated

[0128] Step S300: controlling the working state of each heating plate according to each actual junction temperature, so that the actual junction temperature of each Zener diode to be tested is stabilized to the target junction temperature.

[0129] See also Fig.10 In the embodiment of the present application, step S300 of controlling the working state of each heating plate according to each actual junction temperature also includes sub-steps S310 to S330.

[0130] Step S310: Compare the actual junction temperature with the target junction temperature.

[0131] Step S320: If the actual junction temperature is lower than the target junction temperature, the heating plate is controlled to increase the temperature.

[0132] Step S330: If the actual junction temperature is higher than or equal to the target junction temperature, the heating plate is controlled to stop heating.

[0133] The processing unit compares each actual junction temperature with the target junction temperature, and controls the working state of the corresponding heating plate (i.e., heating up or stopping heating) according to the comparison result, so as to control the junction temperature of each Zener diode to be tested respectively, so that the actual junction temperature of each Zener diode to be tested is stabilized at the target junction temperature, thereby improving the accuracy of the Zener diode aging test.

[0134] In summary, the embodiments of the present application provide a Zener diode aging test circuit and method. Since a heating plate is fixed on each Zener diode to be tested, and each Zener diode to be tested is connected in parallel with a first voltage detection unit, the processing unit can calculate the actual junction temperature according to the stabilizing voltage detected by the first voltage detection unit, and perform PID closed-loop control on the output of the heating plate according to the actual junction temperature. The junction temperature of each Zener diode to be tested can be individually and accurately controlled to ensure that the actual junction temperature of each Zener diode to be tested is stabilized at the target junction temperature required by the test, thereby improving the accuracy of the Zener diode aging test.

[0135] Furthermore, since the embodiment of the present application uses the zener voltage value of the zener diode for junction temperature calibration, the zener voltage is several orders of magnitude higher than the forward voltage used for conventional junction temperature calibration. Therefore, the performance accuracy of the second power supply for outputting the junction temperature test current and the first voltage detection unit for collecting the actual zener voltage of the zener diode to be tested do not need to be particularly precise. Under normal circumstances, a voltmeter of the ordinary multimeter grade can be used for the first voltage detection unit, which greatly reduces the test cost. In addition, by connecting multiple zener diodes to be tested in series for testing, only one electronic load can be used for current regulation, reducing the number of electronic loads used, thereby further reducing the test cost.

[0136] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

[0137] It will be apparent to those skilled in the art that the present application is not limited to the details of the exemplary embodiments described above, and that the present application can be implemented in other specific forms without departing from the spirit or essential features of the present application. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the present application is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims be included in the present application. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

Claims

1. A voltage regulator diode aging test circuit, characterized in that: include: A first power supply and at least one test module, wherein the test module includes a second power supply, a processing unit, and a plurality of equal numbers of voltage-stabilizing diodes to be tested, a heating plate, and a first voltage detection unit; A plurality of the voltage stabilizing diodes to be tested are connected in series and then respectively connected in parallel with the first power supply and the second power supply; wherein the first power supply is used to output an aging test current, and the second power supply is used to output a junction temperature test current; A heating plate is fixed on each of the voltage-stabilizing diodes to be tested, and a first voltage detection unit is connected in parallel to each of the voltage-stabilizing diodes to be tested; the input end of the processing unit is respectively connected to a plurality of the first voltage detection units, and the output end of the processing unit is respectively connected to a plurality of the heating plates; When performing junction temperature calibration on multiple Zener diodes to be tested, multiple first voltage detection units are used to detect the current actual Zener voltages of multiple Zener diodes to be tested; the processing unit is used to calculate the actual junction temperature of each Zener diode to be tested according to each actual Zener voltage, and control the working state of each heating plate according to each actual junction temperature, so that the actual junction temperature of each Zener diode to be tested is stabilized to the target junction temperature.

2. The voltage regulator diode aging test circuit according to claim 1, characterized in that: The test module also includes a first switch and a second switch; one end of the first power supply is connected to one end of a plurality of the voltage-stabilizing diodes to be tested in series through the first switch, and the other end of the first power supply is connected to the other end of a plurality of the voltage-stabilizing diodes to be tested in series; one end of the second power supply is connected to one end of a plurality of the voltage-stabilizing diodes to be tested in series through the second switch, and the other end of the second power supply is connected to the other end of a plurality of the voltage-stabilizing diodes to be tested in series; When performing an aging test on the plurality of Zener diodes to be tested, the first switch is closed and the second switch is opened, so that the first power supply outputs an aging test current to the plurality of Zener diodes to be tested; When performing junction temperature calibration on the plurality of Zener diodes to be tested, the first switch is opened and the second switch is closed, so that the second power supply outputs a junction temperature test current to the plurality of Zener diodes to be tested.

3. The voltage regulator diode aging test circuit according to claim 1, characterized in that: The Zener diode aging test circuit also includes a high-temperature test box, and multiple Zener diodes to be tested are placed in the high-temperature test box. The high-temperature test box is used to increase the test environment temperature and maintain it at a first junction temperature; wherein the first junction temperature is lower than the target junction temperature.

4. The voltage regulator diode aging test circuit according to claim 1, characterized in that: The processing unit includes a collection unit, a calculation unit and a control unit; the input end of the collection unit is respectively connected to the plurality of first voltage detection units, the output end of the collection unit is connected to the input end of the calculation unit, the output end of the calculation unit is connected to the input end of the control unit, and the output end of the control unit is respectively connected to the plurality of heating plates; The acquisition unit is used to acquire a plurality of actual regulated voltages detected by the first voltage detection unit, and send the plurality of actual regulated voltages to the calculation unit; The calculation unit is used to calculate the actual junction temperature of each of the voltage regulator diodes to be tested according to each of the actual regulated voltages, and compare each of the actual junction temperatures with the target junction temperature; If the actual junction temperature is lower than the target junction temperature, the calculation unit sends a first instruction to the control unit; if the actual junction temperature is higher than or equal to the target junction temperature, the calculation unit sends a second instruction to the control unit; The control unit is used to control the heating plate to increase the temperature when receiving the first instruction; the control unit is also used to control the heating plate to stop heating when receiving the second instruction.

5. The voltage regulator diode aging test circuit according to claim 1, characterized in that: The test module also includes an electronic load, one end of which is connected to the first power supply, and the other end of which is connected to one end of a plurality of the voltage-stabilizing diodes to be tested connected in series; the electronic load is used to adjust the magnitude of the aging test current output by the first power supply.

6. The voltage regulator diode aging test circuit according to claim 1, characterized in that: The test module also includes a current detection unit, a second voltage detection unit and an alarm unit; One end of the current detection unit is connected to the first power supply, and the other end of the current detection unit is connected to one end of a plurality of the voltage-stabilizing diodes to be tested connected in series; The second voltage detection unit is connected in parallel to two ends of a plurality of the voltage zener diodes to be tested connected in series; The alarm unit is connected to the current detection unit and the second voltage detection unit respectively, and is used to alarm when the data detected by the current detection unit or the second voltage detection unit is abnormal.

7. A voltage regulator diode aging test method, characterized in that: A processing unit applied to a Zener diode aging test circuit according to any one of claims 1 to 6, the method comprising: Obtaining the actual current regulated voltage of each of the zener diodes to be tested; Calculate the actual junction temperature of each of the voltage regulator diodes to be tested according to each of the actual voltage regulator voltages; The working state of each of the heating plates is controlled according to each of the actual junction temperatures, so that the actual junction temperature of each of the voltage regulator diodes to be tested is stabilized to the target junction temperature.

8. The zener diode aging test method according to claim 7, characterized in that: The step of respectively calculating the actual junction temperature of each of the zener diodes to be tested according to each of the actual regulated voltages comprises: Obtaining the regulated voltage corresponding to the zener diode to be tested under a plurality of different test environment temperatures; Calculating a plurality of Z coefficients according to the plurality of test environment temperatures and the plurality of regulated voltages; When the actual regulated voltage is less than the minimum regulated voltage, the actual junction temperature of the zener diode to be tested is: T j =T A1 -(V Z1 -V Zx ) / Z1 Among them, V Z1 is the minimum regulated voltage among multiple regulated voltages, T A1 is the test environment temperature corresponding to the minimum regulated voltage, Z1 is the Z coefficient corresponding to the minimum regulated voltage; V Zx is the actual voltage regulator voltage of the Zener diode to be tested, T j is the actual junction temperature of the Zener diode to be tested; When the actual regulated voltage is equal to the minimum regulated voltage, the actual junction temperature of the zener diode to be tested is: T j =T A1 ; When the actual regulated voltage is greater than the minimum regulated voltage and less than the maximum regulated voltage, the actual junction temperature of the zener diode to be tested is: T j =T Ak +(V Zx -V Zk ) / Zk Among them, 1 <k<n,V Zk For multiple regulated voltages with V Zx The difference between the minimum regulated voltage and V Zk <V Zx ; T Ak V Zk The corresponding test environment temperature, Zk is V Zk The corresponding Z coefficient; When the actual regulated voltage is equal to the maximum regulated voltage, the actual junction temperature of the zener diode to be tested is: T j =T An ; Among them, T An is the test environment temperature corresponding to the maximum regulated voltage; When the actual regulated voltage is greater than the maximum regulated voltage, the actual junction temperature of the zener diode to be tested is: T j =T An +(V Zx -V Zn ) / Z(n-1) Among them, V Zn is the maximum regulated voltage among multiple regulated voltages, T An is the test environment temperature corresponding to the maximum regulated voltage, and Z(n-1) is the Z coefficient corresponding to the regulated voltage with the smallest difference from the maximum regulated voltage among multiple regulated voltages.

9. The zener diode aging test method according to claim 8, characterized in that: The Z coefficient is obtained according to the following formula: Zm=[V Z(m+1) -V Zm ] / [T A(m+1) -T Am ] Where Zm is the Z coefficient, and 1≤m≤n, T Am is the test environment temperature corresponding to Zm among multiple test environment temperatures, T A(m+1) For multiple test environment temperatures and T Am The test environment temperature with the smallest difference, and T A(m+1) >T Am ; V Zm is the regulated voltage corresponding to Zm among multiple regulated voltages, V Z(m+1) For multiple regulated voltages with V Zm The difference between the minimum regulated voltage and V Z(m+1) >V Zm .

10. The zener diode aging test method according to claim 7, characterized in that: The step of controlling the working state of each of the heating plates according to each of the actual junction temperatures so that the actual junction temperature of each of the voltage regulator diodes to be tested is stabilized to a target junction temperature comprises: comparing the actual junction temperature with the target junction temperature; If the actual junction temperature is lower than the target junction temperature, controlling the heating plate to increase the temperature; If the actual junction temperature is higher than or equal to the target junction temperature, the heating plate is controlled to stop heating.

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