Triode array reliability test method and test circuit thereof

Abstract

The invention discloses a triode array reliability test method and a test circuit thereof, and belongs to the technical field of transistor test. The test method comprises a triode working point confirmation method, a reliability test power confirmation method, a reliability test circuit setting method, a reliability test circuit state monitoring method and a reliability test circuit anti-interference protection method. The test circuit comprises an NPN triode, a B pole voltage reference circuit, a B pole / voltage source constant current bias circuit, a B pole reverse breakdown prevention protection circuit, an E pole constant current bias circuit, an open circuit / poor contact display circuit, a short circuit display circuit and an anti-interference protection circuit. The problems that in the prior art, whether the aging power of the triodes reaches the standard or not cannot be judged, open-circuit or short-circuit triodes cannot be screened out in time, the total aging current is large when batch products are aged under the same power source, and the direct-current aging power of the products fluctuates due to external noise interference or crosstalk between the products are solved. The method is widely applied to reliability test technologies of transistors and transistor arrays.

Description

Technical Field

[0001] The present invention belongs to the field of transistor testing technology, and further relates to the field of triode array testing technology, and in particular to a triode array reliability test method and a test circuit thereof. Background Art

[0002] There are two types of carriers with different polarity charges in the triode that participate in the conduction, playing the role of current amplification and switching in the circuit. The array formed by placing multiple triodes that do not affect each other in the same metal ceramic tube shell is called a triode array (referred to as product). Figure 1 The two-way high-voltage transistor array shown is encapsulated in a metal-ceramic package. Each transistor is electrically connected to the outside world via six metal pins on the package. DC aging is an important reliability test, and the DC aging test circuit for this product must be designed based on the characteristics of the transistor array.

[0003] When performing DC aging on a transistor array, Figure 2 As shown, the existing testing technology has the following shortcomings: 1. The voltage difference between the collector C and emitter E of the transistor is V CE and the current flowing through the C pole I C The value is not always constant, which means that the transistor cannot be subjected to DC aging with constant dissipated power.

[0004] 2. When the transistor is DC aging, only the voltage V at both ends of the transistor C and E can be directly measured by the instrument. CE The difference and the current flowing through the C pole I C The value can determine whether the power of the transistor meets the requirements.

[0005] 3. Transistors with open circuit and short circuit at both ends of C and E poles need to be eliminated. Open circuit and short circuit transistors cannot be easily identified and cannot be screened out in time. Continuing to subject them to DC aging will waste resources and time. In order to facilitate the extraction of the metal pins on the tube shell, it is necessary to purchase a suitable product fixture. The built-in product is then connected to the DC aging test circuit through the pins on the fixture. It is impossible to easily identify whether the pins at both ends of the C and E poles of the transistor are in poor contact with the DC aging test circuit. If the contact is poor, it cannot be guaranteed that the transistor can be DC aged at the required dissipated power, and thus the effect of the DC aging of the transistor cannot be guaranteed.

[0006] 4. The DC aging test circuit for each product is the same. The power supply and ground wires of the DC aging test circuit for each product are connected in parallel. Multiple products (batch products) can be DC aged simultaneously through the same power supply and ground. The total current is relatively large. No effective measures are taken to prevent external noise interference and crosstalk between products, resulting in power fluctuations in the products.

[0007] In view of this, the present invention is proposed. Summary of the Invention

[0008] The technical problem to be solved by the present invention is to solve the problems in the prior art of being unable to determine whether the transistor aging power meets the standard, being unable to timely screen out open-circuited and short-circuited transistors, and solving the problems of large total DC aging current when performing DC aging on multiple products (batch products) simultaneously through the same power supply and ground, and power fluctuations of products caused by external noise interference and crosstalk between products.

[0009] To this end, the present invention provides a transistor array reliability test method. The method is as follows: (1) Take the maximum dissipation power of the transistor array product as the reliability test power standard and set the DC aging power of the product; (2) According to the formula P=V CE ×I C (P is the power applied to the transistor, V CE is the voltage between the transistor collector C and emitter E, I C (collector current) sets a constant voltage difference V between the C and E poles of the transistor CE and the current flowing through the C pole I C value; (3) According to the junction temperature formula of the transistor, combined with the specific process parameters and application environment parameters of the transistor, simulate the maximum allowable junction temperature of the specific transistor; (4) Set the test time at the maximum dissipated power according to the enterprise standard, local standard, national standard, international standard or industry standard for transistor reliability test; (5) Setting up the reliability test circuit: According to the electrical characteristics of the transistor: amplification factor β, working current I c , rated power P, determine the working current in the reliability test, the voltage difference between the C and E poles of the transistor, according to the determined working current I C The voltage difference between the C and E poles of the transistor is V CE Then, a transistor test circuit is designed. The transistor base voltage reference circuit, base / voltage source constant current bias circuit, and emitter constant current bias circuit are used to stabilize the operating point of the transistor in the circuit to avoid the influence of ambient temperature and power consumption heat.

[0010] The base protection circuit is used to protect the transistor to prevent the transistor emitter junction from being reversely broken down when a short circuit occurs at the C and E terminals of the transistor.

[0011] Anti-interference protection circuit is used to prevent external noise interference and crosstalk between products from causing fluctuations in product aging power.

[0012] The reliability test process is fully monitored using a disconnect / poor contact display circuit and a short-circuit display circuit for three operating states: disconnect / poor contact, short-circuit, and normal. When any transistor within the product short-circuits, the short-circuit display circuit activates, and a red light illuminates as a warning. When the product has poor contact or disconnects, the green light indicating normal operation in the disconnect / poor contact display circuit turns off. When the product is undergoing normal reliability testing, the green light indicating normal operation in the disconnect / poor contact display circuit remains on, while the red light in the short-circuit display circuit remains off.

[0013] The reliability test circuit state truth table is shown in Table 1: Table 1 Reliability test circuit state truth table .

[0014] If any transistor in the transistor array is short-circuited, open-circuited, or has poor contact with the test circuit, the reliability test of this transistor cannot be carried out normally. Different indications will be given depending on the short-circuit or open-circuit faults, making it easy to detect and judge failed products in a timely manner.

[0015] (6) Under the action of set power stress and time stress, the transistor array product is subjected to reliability testing to make the product heat up to a temperature close to or reaching the maximum allowable junction temperature of the product, screen out early failure products, eliminate products of poor quality, and retain products that meet the quality requirements.

[0016] The test circuit of the transistor array reliability test method is as follows: Figure 3 As shown. Includes: Transistor (NPN transistor), B-pole voltage reference circuit, B-pole / voltage source constant current bias circuit, B-pole anti-reverse breakdown protection circuit, E-pole constant current bias circuit, open circuit / poor contact display circuit, short circuit display circuit, anti-interference protection circuit.

[0017] The base of the transistor is connected to the input end of the B-pole anti-reverse breakdown protection circuit, and the output end of the B-pole anti-reverse breakdown protection circuit is connected to the negative end of the B-pole voltage reference circuit and the negative end of the B-pole / voltage source constant current bias circuit; the emitter of the transistor is connected to the positive end of the E-pole constant current bias circuit and the negative end of the short-circuit display circuit; the collector of the transistor is connected to the negative end of the open circuit / poor contact display circuit; one end of the anti-interference protection circuit is connected to the positive end of the B-pole / voltage source constant current bias circuit, the positive end of the open circuit / poor contact display circuit, and the power supply VCC end, and the other end of the anti-interference protection circuit is connected to the positive end of the B-pole voltage reference circuit, the negative end of the E-pole constant current bias circuit, the positive end of the short-circuit display circuit, and the power supply GND end.

[0018] The function of the B-pole voltage reference circuit is to fix the B-pole and E-pole voltages of the transistor, and also to ensure that the E-pole constant current bias circuit enters a constant current state; The function of the E-pole constant current bias circuit is to fix the current I flowing through the C-pole. C .

[0019] The function of the B-pole / voltage source constant current bias circuit is to ensure that the current flowing through the B-pole voltage reference circuit causes the B-pole voltage reference circuit to enter the voltage regulation region, thereby fixing the B-pole voltage.

[0020] The function of the anti-interference protection circuit is to prevent external noise interference and crosstalk between products, which may cause power fluctuations in the products.

[0021] The function of the open circuit / poor contact display circuit is to visually judge whether the two ends of the transistor C and E are open circuit or whether the two ends of C and E are in poor contact with the test circuit according to whether it emits light.

[0022] The short-circuit indicator circuit's function is to visually determine if a short circuit exists between transistors C and E based on its illumination, and to determine if the short circuit exists between transistors C and E based on its absence. Regardless of whether transistors C and E are short-circuited, the VCC power supply always has a path for current to flow through the open / poor contact indicator circuit to ground, causing the open / poor contact indicator circuit to illuminate. Regardless of whether transistors C and E are open or in poor contact, the voltage across the branch circuit remains relatively low, so the short-circuit indicator circuit remains silent.

[0023] The B-pole anti-reverse breakdown protection circuit is required to have the characteristics of reduced forward conduction voltage and high reverse breakdown voltage. On the one hand, it will not affect the normal DC aging of the transistor. On the other hand, it prevents the transistor emitter junction from being directly reversely broken down when a short circuit occurs at both ends of the C and E poles of the transistor.

[0024] The present invention has the following advantages: 1. The transistor is subjected to a DC aging test at a constant dissipated power.

[0025] 2. Normal DC aging test status monitoring.

[0026] 3. Monitoring of circuit breakage / poor contact status.

[0027] 4. Short circuit status monitoring.

[0028] 5. The DC aging test is highly efficient. Batch products undergoing DC aging tests at the same time can also prevent external noise interference and crosstalk between products, which may cause power fluctuations in the products.

[0029] The present invention can be widely applied to reliability test technologies of transistors and transistor arrays. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a schematic diagram of the transistor array (dual-channel) circuit structure.

[0031] Figure 2 The figure is a schematic diagram of the structure of the conventional reliability test circuit of the transistor array.

[0032] Figure 3 This is a schematic structural diagram of the principle block diagram (single channel) of the transistor array reliability test circuit of the present invention.

[0033] Figure 4 This is a schematic diagram of the structure of the transistor array reliability test circuit (dual channel) of the present invention.

[0034] In the figure: Q1 and Q2 are NPN transistors, CRD1, CRD2, CRD3, CRD4, CRD5, and CRD6 are constant current diodes, LED1 and LED2 are green light-emitting diodes, LED3 and LED4 are red light-emitting diodes, C1 and C2 are capacitors, Z1, Z2, Z3, and Z4 are voltage regulator diodes, and D1 and D2 are diodes. DETAILED DESCRIPTION

[0035] like Figure 1-4 As shown, taking a dual-channel NPN transistor array as an example, the transistor array reliability test method and its test circuit are specifically implemented as follows: The B-pole voltage reference circuit is a voltage regulator tube.

[0036] The B-pole / voltage source constant current bias circuit is a constant current tube.

[0037] The B-pole anti-reverse breakdown protection circuit is a diode.

[0038] The E-pole constant current bias circuit is a constant current tube.

[0039] The circuit breakage / bad contact display circuit is a green light emitting diode.

[0040] The short circuit display circuit is a series circuit of a voltage regulator tube, a constant current tube and a red light emitting diode, wherein the anode of the voltage regulator tube is connected to the positive end of the constant current tube, and the negative end of the constant current tube is connected to the anode of the red light emitting diode.

[0041] The anti-interference protection circuit is a capacitor.

[0042] The test circuit of the transistor array reliability test method is as follows: Figure 4 As shown. Includes: Q1 and Q2 are NPN transistors, CRD1, CRD2, CRD3, CRD4, CRD5 and CRD6 are constant current tubes, LED1 and LED2 are green light-emitting diodes, LED3 and LED4 are red light-emitting diodes, C1 and C2 are capacitors, Z1, Z2, Z3 and Z4 are voltage regulator tubes, and D1 and D2 are diodes.

[0043] The B-pole voltage reference circuit of Q1 is Z1, and the B-pole voltage reference circuit of Q2 is Z2.

[0044] The B-pole / voltage source constant current bias circuit of Q1 is CRD1, and the B-pole / voltage source constant current bias circuit of Q2 is CRD2.

[0045] The B-pole anti-reverse breakdown protection circuit of Q1 is D1, and the B-pole anti-reverse breakdown protection circuit of Q2 is D2.

[0046] The E-pole constant current bias circuit of Q1 is CRD3, and the E-pole constant current bias circuit of Q2 is CRD6.

[0047] The circuit displaying the disconnection / poor contact of Q1 is LED1, and the circuit displaying the disconnection / poor contact of Q2 is LED2.

[0048] The short-circuit display circuit of Q1 includes Z3, CRD4, and LED3, and the short-circuit display circuit of Q2 includes Z4, CRD5, and LED4.

[0049] The anti-interference protection circuit of Q1 is C1, and the anti-interference protection circuit of Q2 is C2.

[0050] The base of Q1 is connected to the cathode of D1, the anode of D1 is connected to the cathode of Z1 and the negative terminal of CRD1; the emitter of Q1 is connected to the positive terminal of CRD3 and the cathode of Z3; the collector of Q1 is connected to the cathode of LED1; one end of C1 is connected to the positive terminal of CRD1, the anode of LED1, and the power supply VCC terminal, and the other end of C1 is connected to the anode of Z1, the negative terminal of CRD3, the cathode of LED3, and the power supply GND terminal; the anode of Z3 is connected to the positive terminal of CRD4, and the negative terminal of CRD4 is connected to the anode of LED3.

[0051] The base of Q2 is connected to the cathode of D2, the anode of D2 is connected to the cathode of Z2 and the negative end of CRD2; the emitter of Q2 is connected to the positive end of CRD6 and the cathode of Z4; the collector of Q2 is connected to the cathode of LED2; one end of C2 is connected to the positive end of CRD2, the anode of LED2, and the power supply VCC end, and the other end of C2 is connected to the anode of Z2, the negative end of CRD6, the cathode of LED4, and the power supply GND end; the anode of Z4 is connected to the positive end of CRD5, and the negative end of CRD5 is connected to the anode of LED4.

[0052] like Figure 4 The working principle of the test circuit shown is qualitatively analyzed as follows: In order to ensure the DC aging effect of the transistor, the power of the transistor must be stabilized at the dissipated power P totNearby, according to the formula P=V CE ×I C , so the voltage V across the C and E poles of the fixed transistor is selected CE and the current flowing through the C pole I C value.

[0053] If DC aging is performed in the transistor saturation region, both the emitter and collector junctions are forward biased V CE <V BE , so V CE The value is almost less than 0.7V, and the current flowing through the C pole , the value is greater than the maximum collector current I CM The transistor cannot withstand such a large current, which will damage the transistor, so DC aging is performed in the amplification area, that is, the voltage V CE The value of is relatively large.

[0054] (1) Stabilize the power circuit of the product The function of the voltage regulator Z1 and Z2 is to fix the voltage of the B and E poles of the transistor, and also to ensure that the CRD3 and CRD6 constant current tubes enter the constant current region; the function of the constant current tubes CRD3 and CRD6 is to fix the current I flowing through the E pole. E , I E =I C +I B , the base current I B It is very small and can be basically ignored, so the current flowing through the C pole I C To fix the voltage difference between the C and E terminals of the transistor, V CE , you can first fix the E-pole voltage, according to V E =V B -V BE , V BE The voltage of the E pole can be fixed by the voltage of the B pole. The B pole is connected to the ground through a voltage regulator tube Z1 and Z2 in series to fix the voltage of the B pole. At the same time, the voltage of the E pole is also fixed. Connect a voltage of V CE +V E The VCC power supply of the transistor C is fixed, and the voltage across the transistor C and E is V CE The difference will be fixed and the transistor enters the amplification region. Now the voltage difference between the B, C, and E poles of the transistor and the voltage difference between the C and E poles is V CE All are fixed, to fix I C The current is According to I E =I C +I B , the base current I B Very small, basically negligible, fixed current I flowing through the E pole E , C-pole current IC The voltage across the E pole is V E The constant current tubes CRD3 and CRD6 enter the constant current area, and the current value of the constant current tubes CRD3 and CRD6 when entering the constant current area is , I C The current is fixed at .

[0055] The function of constant current tubes CRD1 and CRD2 is to ensure that the current flowing through voltage regulator tubes Z1 and Z2 is large and constant, so that voltage regulator tubes Z1 and Z2 enter the voltage regulation area and the voltage of the B pole is fixed. Constant current tubes CRD1 and CRD2 are connected in series between the VCC power supply and the B pole, and the voltage across the constant current tubes CRD1 and CRD2 is fixed at VCC-V B Therefore, the model of constant current tube CRD1 and CRD2 is selected so that the voltage value at both ends is VCC-V B It can provide a larger and more constant current for the voltage regulator Z1 and Z2. The constant current tubes CRD1 and CRD2 also provide current for the B pole. The forward current transmission ratio of the transistor is relatively large. C The current is fixed, I B The current is very small, and most of the current of the constant current tubes CRD1 and CRD2 flows into the voltage regulator tubes Z1 and Z2. The voltage across the constant current tubes CRD1 and CRD2 is VCC-V B When the current flowing through the voltage regulator tubes Z1 and Z2 is the constant current value of the constant current tubes CRD1 and CRD2, it can enter the constant voltage region, thereby providing a constant voltage for the constant current tubes CRD1 and CRD2.

[0056] The function of capacitors C1 and C2 is to prevent external noise interference and crosstalk between products, which may cause power fluctuations in the product. Figure 4 The figure below shows a DC aging test circuit for a single transistor (dual-channel). To improve DC aging efficiency, batches of products can be aging simultaneously using the same DC aging test circuit. The power and ground wires of each transistor's DC aging test circuit can be connected in parallel. Using the same power and ground for DC aging results in a relatively high total current. To prevent power fluctuations caused by external noise and crosstalk between products, a capacitor is connected in parallel between the power and ground wires of each transistor.

[0057] (2) Test status monitoring circuit part The function of green light emitting diodes LED1 and LED2 is to visually judge whether the C and E terminals of the transistor are open circuit or whether the C and E terminals are in poor contact with the DC aging test circuit according to whether they are emitting light. Connect green light emitting diodes LED1 and LED2 in series with the C terminal of the transistor and connect them to the VCC power supply. The voltage value of the VCC power supply is V CE +V E On this basis, the voltage value of the green light-emitting diodes LED1 and LED2 when they are normally emitting light is added, and the current energy I of the normal DC aging of the transistor is C Make the green light-emitting diodes LED1 and LED2 emit light normally. When the green light-emitting diodes emit light normally, the voltage across the two ends and the current flowing through them are fixed, so the green light-emitting diodes can emit light normally during normal DC aging of the transistor; once the C and E poles are broken or in poor contact, the current flowing through the green light-emitting diodes LED1 and LED2 is zero, and the green light-emitting diodes LED1 and LED2 do not emit light.

[0058] The function of the red light-emitting diodes LED3 and LED4 is to visually judge whether the C and E terminals of the transistor are short-circuited by their light emission, and to judge whether the C and E terminals of the transistor are not short-circuited by their absence of light. A branch is formed by the red light-emitting diodes LED3 and LED4, constant current diodes CRD4 and CRD5, and voltage regulator diodes Z3 and Z4. This branch is connected in parallel between the E terminal of the transistor and the ground. The voltage threshold of the voltage regulator diodes Z3 and Z4 entering the voltage regulation area is higher than the E terminal voltage V of the transistor during normal DC aging. E The constant current transistors CRD4 and CRD5 prevent excessive current from flowing into this branch, protecting the voltage regulator and the red LED. During normal DC aging of the transistors, the voltage across the branch is relatively low, and the current flowing through the branch is insufficient to illuminate the red LED. When transistor CE is short-circuited, the voltage across the branch is relatively high, and the current flowing through the branch causes the red LEDs LED3 and LED4 to illuminate.

[0059] Regardless of whether the C and E poles of the transistor are short-circuited, the VCC power supply always has a path for current to pass through the green light-emitting diode to the ground, and the green light-emitting diodes LED1 and LED2 both emit light; regardless of whether the C and E poles of the transistor are open-circuited or in poor contact, the voltage at both ends of the branch is relatively small, and the red light-emitting diodes LED3 and LED4 do not emit light.

[0060] The diodes D1 and D2 have the characteristics of reduced forward voltage and high reverse breakdown voltage, which have two functions. ①, by reducing the forward voltage, it will not affect the normal DC aging of the transistor; ②, by using the high reverse breakdown voltage, it can prevent the transistor collector junction from being directly reversely broken down when the C and E terminals of the transistor are short-circuited. CMost of the current flows from the voltage-stabilizing diodes Z1 and Z2 to the ground, resulting in a relatively small voltage at both ends of the branch formed by the red light-emitting diodes LED3 and LED4, constant current diodes CRD4 and CRD5, and the voltage-stabilizing diodes Z3 and Z4. The current flowing through the branch is not enough to make the red light-emitting diode emit light, and the red light-emitting diode does not emit light. Therefore, it is impossible to determine that there is a short circuit between the C and E poles of the transistor by the fact that the red light-emitting diode does not emit light.

[0061] The test circuit has the following advantages: (1) The transistor is subjected to DC aging with a constant dissipation power. The voltage regulator provides a constant voltage to the constant current transistor to make it enter the constant current region. At the same time, the constant current transistor provides a constant voltage to the voltage regulator to make it enter the voltage regulation region. Therefore, the voltage difference between the C and E poles of the transistor is V. CE and the current flowing through the C pole I C The value is constant.

[0062] (2) Normal DC aging prompt function: In the DC aging test circuit of a transistor, when the green LED lights up and the red LED does not light up, it indicates that the transistor is undergoing normal DC aging.

[0063] (3) Open circuit / poor contact prompt function: In the DC aging test circuit of a transistor, when the green LED and the red LED do not light up, it means that the C and E poles of the transistor are open circuited or the C and E poles have poor contact with the DC aging test circuit, which reminds the operator to check in time, screen out the products with open circuits at the C and E poles, or adjust the electrical connection between the C and E pole pins of the tube shell and the DC aging test circuit.

[0064] (4) Short circuit indication function: When the green LED and the red LED are both on, it indicates that the product is abnormal, usually manifested as a short circuit between the C and E poles, reminding the operator to check in time and screen out the products with short circuit between the C and E poles.

[0065] (5) High efficiency of DC aging: DC aging is performed on batches of products at the same time, which can also prevent external noise interference and crosstalk between products, which may cause power fluctuations in the products.

[0066] The state truth table of the test circuit of the above embodiment is shown in Table 2: Table 2. Circuit state truth table of the reliability test of the embodiment

[0067] like Figure 4 The working principle of the test circuit shown is quantitatively analyzed as follows: based on Figure 4The three working states of the transistor array DC aging test circuit are analyzed for the dual-channel transistor array in a single product to determine the feasibility and reliability of the circuit design.

[0068] 1. When the DC-aged transistor array works normally When a single-channel DC aging test circuit works normally, the I 总 =13.6mA, VCC=22.5V, the voltage difference between the C and E terminals of the transistor is V CE =15V and the current flowing through the C pole I C =8mA, the power of the transistor is stable at the dissipated power P tot Nearby, the current flowing through the green LED is 8mA, which makes it emit light; the current flowing through the red LED is zero, which makes it not emit light.

[0069] 2. When the C and E poles of the transistor array aged by DC are broken or in poor contact Since each channel of the transistor array is independent of each other and does not affect each other, when the C and E poles of a single-channel transistor are disconnected or in poor contact, the current flowing through the C pole I C =0mA, the current flowing through the green light-emitting diode is also zero, and it does not emit light; the current flowing through the red light-emitting diode is also zero, and it does not emit light.

[0070] If the DC aging test circuit of the other channel works normally, it is consistent with the description of Case 1 above.

[0071] 3. When the C and E terminals of the transistor array aged by DC are short-circuited Since each channel of the transistor array is independent of each other and does not affect each other, when the C and E poles of a single channel transistor are short-circuited, the voltage difference V CE =0V, the voltage at both ends of the branch formed by the red light-emitting diode, constant current tube and voltage regulator tube is relatively large. The current flowing through the red light-emitting diode is 1mA, and it emits light; the current flowing through the green light-emitting diode is 9mA, and it emits light.

[0072] If the DC aging test circuit of the other channel works normally, it is consistent with the description of Case 1 above.

[0073] In the test circuit, the NPN transistor can be replaced with a PNP transistor, and the polarity of the relevant circuits in the test circuit is changed accordingly.

[0074] In the test circuit, the NPN transistor can be replaced with a MOS transistor or an IGBT transistor, and the polarity of the relevant circuits in the test circuit is changed accordingly.

[0075] Finally, it should be noted that the above embodiments are merely examples for clarity of description. The present invention includes, but is not limited to, the above embodiments. An exhaustive list of all possible implementations is not necessary and cannot be provided here. Those skilled in the art will appreciate that other variations or modifications can be made based on the above description. Any implementation that meets the requirements of the present invention falls within the scope of protection of the present invention.

Claims

1. A transistor array reliability test method, characterized in that: The following methods are included: (1) Take the maximum dissipation power of the transistor array product as the reliability test power standard and set the DC aging power of the product; (2) According to the formula P=V CE ×I C (P is the power applied to the transistor, V CE is the voltage between the transistor collector C and emitter E, I C (collector current) sets a constant voltage difference V between the C and E poles of the transistor CE and the current flowing through the C pole I C value; (3) According to the junction temperature formula of the transistor, combined with the specific process parameters and application environment parameters of the transistor, simulate the maximum allowable junction temperature of the specific transistor; (4) Set the test time at the maximum dissipated power according to the enterprise standard, local standard, national standard, international standard or industry standard for transistor reliability test; (5) Setting up the reliability test circuit: According to the electrical characteristics of the transistor: amplification factor β, working current I c , rated power P, determine the working current in the reliability test, the voltage difference between the C and E poles of the transistor, according to the determined working current I C The voltage difference between the C and E poles of the transistor is V CE Then, a transistor reliability test circuit is designed; the transistor base voltage reference circuit, base / voltage source constant current bias circuit, and emitter constant current bias circuit are used to stabilize the operating point of the transistor in the circuit; The base protection circuit is used to protect the transistor to prevent the transistor emitter junction from being reversely broken down when a short circuit occurs at the C and E terminals of the transistor. Use anti-interference protection circuit to prevent external noise interference and crosstalk between products from causing product power fluctuations; The open circuit / poor contact display circuit and the short circuit display circuit are used to monitor the three working states of open circuit / poor contact, short circuit and normal during the reliability test. When any transistor inside the product is short-circuited, the short circuit display circuit is activated and the red light is on to prompt. When the product has poor contact or open circuit, the normal working green light in the open circuit / poor contact display circuit goes out. When the product is undergoing normal reliability test screening, the normal working green light in the open circuit / poor contact display circuit is always on, and the red light in the short circuit display circuit is always off. The reliability test circuit state truth table is: In the table: indicator light "1" is on, "0" is off; (6) Under the action of set power stress and time stress, the transistor array products are subjected to reliability tests to make the products heat up to a temperature close to or reaching the maximum allowable junction temperature of the products, screen out early failure products, eliminate products of poor quality, and retain products that meet the quality requirements.

2. The test circuit for a transistor array reliability test method according to claim 1, wherein: Including NPN transistor, B-pole voltage reference circuit, B-pole / voltage source constant current bias circuit, B-pole anti-reverse breakdown protection circuit, E-pole constant current bias circuit, open circuit / bad contact display circuit, short circuit display circuit, anti-interference protection circuit; The base of the transistor is connected to the input end of the B-pole anti-reverse breakdown protection circuit, and the output end of the B-pole anti-reverse breakdown protection circuit is connected to the negative end of the B-pole voltage reference circuit and the negative end of the B-pole / voltage source constant current bias circuit; the emitter of the transistor is connected to the positive end of the E-pole constant current bias circuit and the negative end of the short-circuit display circuit; the collector of the transistor is connected to the negative end of the open circuit / poor contact display circuit; one end of the anti-interference protection circuit is connected to the positive end of the B-pole / voltage source constant current bias circuit, the positive end of the open circuit / poor contact display circuit, and the power supply VCC end, and the other end of the anti-interference protection circuit is connected to the positive end of the B-pole voltage reference circuit, the negative end of the E-pole constant current bias circuit, the positive end of the short-circuit display circuit, and the power supply GND end.

3. The test circuit of the transistor array reliability test method according to claim 2, wherein: The B-pole voltage reference circuit is a voltage regulator tube, the B-pole / voltage source constant current bias circuit is a constant current tube, and the B-pole anti-reverse breakdown protection circuit is a diode.

4. The test circuit of the transistor array reliability test method according to claim 2, wherein: The E-pole constant current bias circuit is a constant current tube.

5. The test circuit of the transistor array reliability test method according to claim 2, wherein: The circuit breakage / bad contact display circuit is a green light emitting diode.

6. The test circuit of the transistor array reliability test method according to claim 2, wherein: The short circuit display circuit is a series circuit of a voltage regulator tube, a constant current tube and a red light emitting diode, wherein the anode of the voltage regulator tube is connected to the positive end of the constant current tube, and the negative end of the constant current tube is connected to the anode of the red light emitting diode.

7. The test circuit of the transistor array reliability test method according to claim 2, wherein: The anti-interference protection circuit is a capacitor.

8. The test circuit for a transistor array reliability test method according to claim 2, wherein: Including NPN transistors Q1, Q2, constant current tubes CRD1, CRD2, CRD3, CRD4, CRD5, CRD6, green light-emitting diodes LED1, LED2, red light-emitting diodes LED3, LED4, capacitors C1, C2, voltage regulator tubes Z1, Z2, Z3, Z4, diodes D1, D2; The base of Q1 is connected to the cathode of D1, the anode of D1 is connected to the cathode of Z1 and the negative terminal of CRD1; the emitter of Q1 is connected to the positive terminal of CRD3 and the cathode of Z3; the collector of Q1 is connected to the cathode of LED1; one end of C1 is connected to the positive terminal of CRD1, the anode of LED1, and the power supply VCC terminal, and the other end of C1 is connected to the anode of Z1, the negative terminal of CRD3, the cathode of LED3, and the power supply GND terminal; the anode of Z3 is connected to the positive terminal of CRD4, and the negative terminal of CRD4 is connected to the anode of LED3; The base of Q2 is connected to the cathode of D2, the anode of D2 is connected to the cathode of Z2 and the negative end of CRD2; the emitter of Q2 is connected to the positive end of CRD6 and the cathode of Z4; the collector of Q2 is connected to the cathode of LED2; one end of C2 is connected to the positive end of CRD2, the anode of LED2, and the power supply VCC end, and the other end of C2 is connected to the anode of Z2, the negative end of CRD6, the cathode of LED4, and the power supply GND end; the anode of Z4 is connected to the positive end of CRD5, and the negative end of CRD5 is connected to the anode of LED4.

9. The test circuit of a transistor array reliability test method according to claim 2, wherein: The NPN transistor is replaced with a PNP transistor, and the polarity of the relevant circuits in the test circuit is changed accordingly.

10. The test circuit of the transistor array reliability test method according to claim 2, wherein: The NPN transistor is replaced with a MOS transistor or an IGBT transistor, and the polarity of the relevant circuits in the test circuit is changed accordingly.

Images