A reliability test method for a zener diode array and its test circuit

Abstract

A reliability test method and test circuit for a voltage stabilizing diode array, belonging to the field of semiconductor voltage stabilizing diode testing. It includes: using a constant current tube to provide a power aging current to the voltage stabilizing diode array to be tested, while monitoring and protecting the voltage stabilizing diode array to be tested; using a light-emitting diode and a voltage stabilizing diode to form a short-circuit indication circuit to feedback the short-circuit problem of the aging product; using a light-emitting diode and a constant current tube to form an aging indication circuit, protecting the normal operation of the light-emitting diode through the constant current tube, and at the same time used for product open-circuit indication; using a shunt circuit to limit the current of the aging path to protect the voltage stabilizing diode array to be tested and other components; using a DIP switch to specify the circuit aging of a certain path of the voltage stabilizing diode array to be tested; connecting an ammeter in series at one end of the DIP switch to achieve single-path current monitoring. It solves the problems of large current fluctuation in the existing semiconductor voltage stabilizing diode aging circuit and no protection measures in the circuit. It is widely used in the power aging of semiconductor voltage stabilizing diode series products.

Description

Technical Field

[0001] The present invention belongs to the field of semiconductor voltage regulator diode testing, and further relates to the field of semiconductor voltage regulator diode reliability testing. Specifically, it relates to a reliability test method and test circuit for a multi-channel voltage regulator array. Background Art

[0002] The purpose of the burn-in test is to screen or eliminate unqualified devices. The aging test of semiconductor voltage regulator diodes (referred to as voltage regulator tubes for short) usually adopts power aging. The voltage regulator tubes are subjected to full-power aging at their rated power. After the voltage regulator tubes break down, the voltage value approaches stability, and the rated power of the voltage regulator tubes is mainly achieved by adjusting the current value. The commonly used method is to connect a current-sharing resistor in series with the voltage regulator tube, and the current at both ends of the voltage regulator tube is adjusted through the current-sharing resistor.

[0003] Figure 1 For the existing power burn-in circuit of voltage regulator tubes, its working principle is: by adjusting the power supply voltage, the voltage regulator tubes work in the reverse breakdown region V Z , and at the same time the working current I=(V vcc -V Z ) / R. By changing the output voltage of the voltage or the resistance value of the current-sharing resistor, the working current I reaches the reverse maximum working current I ZM . The maximum burn-in power P tot =V Z *I ZM , so as to achieve the purpose of burn-in.

[0004] Figure 1 The circuit shown mainly has the following problems: First, the accuracy of the current-sharing resistor directly affects the current accuracy of the burn-in products. The resistance value of the resistor will also fluctuate after being heated, resulting in fluctuations in the burn-in current, which is unstable for the product life, thus causing the quality and reliability to be out of control; Second, there is no protection measure in the circuit. When the power fluctuation is serious, the product is directly damaged, and in severe cases, it may cause faults such as power supply overload and resistor fusing. It is necessary to support an aging platform for auxiliary aging, resulting in a substantial increase in cost.

[0005] In view of this, the present invention is specifically proposed. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to solve the problems of large current fluctuations in the existing semiconductor voltage regulator diode burn-in circuit and no protection measures in the circuit.

[0007] In the conventional aging circuit, for the short-circuit problem caused by device short-circuit or other reasons, the choice is to add a fuse tube to protect other devices and the power supply.

[0008] The present invention provides a method for testing the reliability of a voltage regulator diode array. According to the specific operating current of the product, a constant current diode (current regulating diode) is used to monitor and protect the device. At the same time, the form of "optical alarm" is adopted to timely remind the operator of the problems generated. The circuit designed with a constant current diode replaces the fuse tube, avoiding the replacement of the fuse tube that has failed due to melting, making the circuit work more efficiently and stably.

[0009] The current regulating diode is used to control the operating current at both ends of the voltage regulator diode. Compared with before, a more accurate and stable current value can be obtained, and it is not affected by the voltage fluctuations of the power supply and the aged products. Its rated power P tot = I ZM * V Z where there is no variable, and the power aging is more stable. At the same time, the functions of short-circuit protection, open-circuit protection and alarm prompt are designed. When the product is aged, the short-circuit and open-circuit states of the product can be observed in real time, reducing potential safety hazards.

[0010] The specific reliability test method is as follows:

[0011] (1) According to the specific operating current of the product, a constant current diode is used to provide power aging current for the voltage regulator diode array to be tested, and at the same time, the voltage regulator diode array to be tested is monitored and protected;

[0012] (2) A short-circuit indication circuit is composed of a light-emitting diode and a voltage regulator diode. When the aged product works normally, the short-circuit indication circuit does not work. When the aged product has a short circuit, the light-emitting diode lights up, thus reflecting the short-circuit problem of the aged product;

[0013] (3) An aging indication circuit is composed of a light-emitting diode and a constant current diode. The constant current diode protects the normal operation of the light-emitting diode and is used for indicating the open circuit of the product at the same time;

[0014] (4) A shunt circuit is used to limit the current of the aging path to prevent excessive current from damaging the voltage regulator diode array to be tested and other components in the circuit when the voltage regulator diode array to be tested fails;

[0015] (5) A DIP switch is used to specify the circuit aging of a certain path of the voltage regulator diode array to be tested by dialing;

[0016] (6) One end of the DIP switch is connected in series with an ammeter to realize single-path current monitoring.

[0017] The present invention provides a reliability test circuit for a voltage regulator diode array, as Figure 2 shown. It includes a DC voltage source VCC, a light-emitting diode 1, a voltage regulator diode 1, a constant current diode 1, a voltage regulator diode array to be tested, a DIP switch, a shunt resistor, a light-emitting diode 2, and a constant current diode 2.

[0018] The positive electrode of the light-emitting diode 1, the positive electrode of the constant-current diode 1 are connected to the DC voltage source VCC. The negative electrode of the light-emitting diode 1 is connected to the negative electrode of the voltage-regulating diode 1. The positive electrode of the voltage-regulating diode 1 and the negative electrode of the constant-current diode 1 are connected to the negative electrode of the voltage-regulating diode array to be measured. One end of the DIP switch is connected to the positive electrode of the voltage-regulating diode array to be measured, and the other end of the DIP switch is connected to one end of the shunt resistor and the positive electrode of the light-emitting diode 2. The negative electrode of the light-emitting diode 2 is connected to the positive electrode of the constant-current diode 2. The other end of the shunt resistor and the negative electrode of the constant-current diode 2 are connected to the ground terminal.

[0019] The light-emitting diode 1 and the voltage-regulating diode 1 are connected in series to form a short-circuit indication circuit. When the aging product works normally, the short-circuit indication circuit does not work. When the aging product has a short circuit, the voltage across the short-circuit indication circuit increases, causing the voltage-regulating diode to break down and the LED light-emitting diode to light up, thereby feedbacking the short-circuit problem of the aging product.

[0020] The constant-current diode 1 provides a constant working current for the voltage-regulating diode array to be measured, monitors and protects the voltage-regulating diode array to be measured, avoids the replacement of the fuse that has blown and failed, and makes the circuit work more efficiently and stably.

[0021] The light-emitting diode 2 and the constant-current diode 2 are connected in series to form an aging indication circuit. The constant-current diode 2 protects the normal operation of the light-emitting diode 2 (product aging indicator light), and is also used for product open-circuit indication.

[0022] The shunt resistor plays a current-limiting role in the aging path, and can effectively prevent excessive current from damaging the product and other components in the circuit when the product fails.

[0023] The DIP switch is used to specify the circuit aging of a certain path of the voltage-regulating diode array to be measured by dialing, and can realize single-path current monitoring by connecting an ammeter in series.

[0024] This circuit has the following functions at the same time:

[0025] (1) Aging indication function: Only the working indicator light is on, indicating that the product is aging normally.

[0026] (2) Short-circuit indication function: When the short-circuit indicator light is on, it indicates that the product is abnormal, usually manifested as a short circuit at the output end or the breakdown voltage is abnormally small.

[0027] (3) Open-circuit indication function: When the working indicator light is off, it indicates that the product has an open-circuit problem.

[0028] (4) Circuit monitoring function: When designing this circuit, the DIP switch is cleverly designed in the aging branch. Usually, it acts as a wire and can be used for the aging function of the specified path. Similarly, an ammeter can also be connected in parallel at both ends of the DIP switch and the DIP switch is disconnected to monitor the current in the branch.

[0029] (5) Overcurrent and short - circuit protection function: A voltage - stabilizing diode and a shunt resistor are designed in the circuit, which can effectively prevent excessive current from damaging the product and other components in the circuit when the product fails.

[0030] The main advantages are as follows:

[0031] (1) The aging power stability is good, solving the problem of introducing uncontrollable quality factors in the aging process of the existing aging circuit.

[0032] (2) It has short - circuit protection, over - current protection, normal aging indication and short - circuit state indication functions.

[0033] (3) The circuit is simple, with complete functions, and is easy to expand in parallel. It has good feasibility, maintainability and popularization. Without professional aging equipment, only by connecting to the power supply can the power aging be completed. It reduces the operation pressure, greatly improves the aging efficiency, reduces the aging equipment, and reduces the production cost.

[0034] It is widely used in the power aging of semiconductor voltage - stabilizing diode series products. Description of the Drawings

[0035] Figure 1 It is a schematic diagram of the existing voltage - stabilizing diode aging circuit.

[0036] Figure 2 It is a schematic diagram of the principle of a single - channel aging circuit.

[0037] Figure 3 It is a schematic diagram of the principle of a multi - channel aging circuit. Detailed Implementation Modes

[0038] As Figure 3 shown, taking the CDIP16 - type 8 - channel voltage - stabilizing array product as an example, the detailed implementation modes are as follows:

[0039] The 8 - channel constant - current and short - circuit indication circuits are respectively connected to the input ends of the 8 - channel voltage - stabilizing array. The output ends of the 8 - channel voltage - stabilizing array are respectively connected to the input ends of the 8 - bit DIP switches. The 8 - channel aging indication circuits and shunt circuits are respectively connected to the output ends of the 8 - bit DIP switches.

[0040] The 8 single - channel aging circuits are independent of each other, and the parameters of the components forming the circuit are the same, ensuring that the aging power of each channel is the same.

[0041] In terms of the layout of the aging circuit board, an axisymmetric structural feature is adopted. Taking the 8 - channel voltage - stabilizing array and the 8 - bit DIP switch as the axis, the 8 - channel constant - current and short - circuit indication circuits, the 8 - channel aging indication circuits and shunt circuits are symmetrically located on the left and right sides of the axis respectively.

[0042] On the left side are the voltage stabilizer and the LED indicator. This circuit does not work when the aging product is operating normally. When a short circuit occurs in the aging product, the voltage across both ends of this circuit increases, causing the voltage regulator diode to break down and the LED to light up, thus feedbacking the short circuit problem of the aging product.

[0043] On the right side is the product aging indicator, which protects the normal operation of the LED through a constant current source and is also used for indicating product open circuit.

[0044] The aging product is followed by an eight-bit DIP switch. The DIP switch can be used to specify the aging of a specific circuit, and the single-channel current monitoring function can be achieved by connecting an ammeter in series.

[0045] Finally, it should be noted that the above embodiments are merely examples given for clear illustration. The present invention includes but is not limited to the above embodiments, and it is not necessary and impossible to enumerate all implementation manners here. For those of ordinary skill in the art, other different forms of changes or variations can be made based on the above description. All implementation manners that meet the requirements of the present invention fall within the protection scope of the present invention.

Claims

1. A reliability test method for a voltage - regulating diode array, characterized in that, it includes the following methods: (1) According to the specific operating current of the product, use a constant - current tube to provide a power - aging current to the voltage - regulating diode array to be tested, and at the same time monitor and protect the voltage - regulating diode array to be tested; (2) Use a light - emitting diode and a voltage - regulating diode to form a short - circuit indication circuit. When the aging product works normally, the short - circuit indication circuit does not work. When the aging product has a short - circuit, the light - emitting diode lights up, thus feeding back the short - circuit problem of the aging product; (3) Use a light - emitting diode and a constant - current tube to form an aging indication circuit, protect the normal operation of the light - emitting diode through the constant - current tube, and at the same time be used for product open - circuit indication; (4) Use a shunt circuit to limit the current in the aging path to prevent excessive current from damaging the voltage - regulating diode array to be tested and other components in the circuit when the voltage - regulating diode array to be tested fails; (5) Use a DIP switch to specify the aging of a certain path of the voltage - regulating diode array to be tested by dialing; (6) Connect an ammeter in series at one end of the DIP switch to achieve single - path current monitoring; The test circuit of the reliability test method includes: DC voltage source VCC, light - emitting diode 1, voltage - regulating diode 1, constant - current diode 1, voltage - regulating diode array to be tested, DIP switch, shunt resistor, light - emitting diode 2, constant - current diode 2; The positive pole of light - emitting diode 1 and the positive pole of constant - current diode 1 are connected to DC voltage source VCC. The negative pole of light - emitting diode 1 is connected to the negative pole of voltage - regulating diode 1. The positive pole of voltage - regulating diode 1 and the negative pole of constant - current diode 1 are connected to the negative pole of the voltage - regulating diode array to be tested. The positive pole of the voltage - regulating diode array to be tested is connected to one end of the DIP switch. The other end of the DIP switch is connected to one end of the shunt resistor and the positive pole of light - emitting diode 2. The negative pole of light - emitting diode 2 is connected to the positive pole of constant - current diode 2. The other end of the shunt resistor and the negative pole of constant - current diode 2 are connected to the ground terminal.

2. A reliability test method for a voltage - regulating diode array according to claim 1, characterized in that, the voltage - regulating diode array to be tested is an 8 - path voltage - regulating array.

3. A reliability test method for a voltage - regulating diode array according to claim 2, characterized in that, the model of the 8 - path voltage - regulating array is CDIP16.

4. A reliability test method for a voltage - regulating diode array according to claim 1, characterized in that, the DIP switch is a multi - position DIP switch.

5. A reliability test method for a voltage - regulating diode array according to claim 4, characterized in that, the multi - position DIP switch is an 8 - position DIP switch.

6. A reliability test method for a voltage - regulating diode array according to claim 4, characterized in that, the multi - position DIP switch specifies the unit aging circuit by dialing.

7. A reliability test method for a voltage - regulating diode array according to claim 1, characterized in that, each unit aging circuit is independent of each other, and the parameters of the components forming the circuit are the same.

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