Chip aging test system

Abstract

The invention provides a chip aging test system, which is characterized in that a signal isolation circuit is arranged between a control circuit and a heating circuit, and a first photoelectric coupler in the signal isolation circuit is used for converting a first control signal output by the control circuit into a first optical signal; then the first optical signal is converted into a second control signal to be output to the heating circuit, the heating switch is controlled to be switched on and off to reach the corresponding heating power, electric signal isolation between the control circuit and the heating circuit is achieved, meanwhile, the control circuit is grounded through a first grounding circuit, and the heating circuit is grounded through a second grounding circuit; therefore, the grounding lines of the heating circuit and the control circuit are mutually independent and do not interfere with each other, and the interference of noise generated by the output signal of the heating circuit on the control circuit can be reduced under the conditions that the heating power is relatively high and the current of the output signal of the heating circuit is relatively large, so that the accuracy of the chip aging test is improved.

Description

Technical Field

[0001] The present disclosure relates to automated testing technology, and in particular to a chip aging testing system. Background Art

[0002] Chip burn-in testing is used to verify chip reliability. By simulating extreme environments such as high temperature, high voltage, and high current, the chip's aging process is accelerated, screening out chips prone to failure quickly and ensuring the stability and lifespan of shipped chips. High-temperature accelerated aging works by increasing the temperature to speed up chemical reactions, thereby shortening the chip's lifespan. During high-temperature burn-in testing, the chip under test must be equipped with a high-power heating system capable of quickly responding to test signals to ensure temperature stability during the test.

[0003] The temperature control system for chip aging testing usually consists of a heating circuit (heating rod, heating tile, etc.), a cooling system (liquid cooling system, air cooling system, etc.), and a temperature sensor. The output power of the heating circuit must be large enough and the response must be fast enough to accurately control the temperature of the chip under test within a specific temperature range.

[0004] In related technologies, the output power of a single heater rod is typically tens of watts, and the power supply voltage and current of a single-channel heating circuit are relatively weak (for example, the voltage is typically less than 24V and the current is typically less than 3A), thus requiring relatively simple control circuit design. However, in test scenarios where a single-channel heating circuit is required to output power of several hundred watts, the noise generated by the pulse width modulation (PWM) signal output by the heating circuit can significantly interfere with the control circuit, thereby affecting the temperature stability of the chip under test. Summary of the Invention

[0005] The embodiments of the present disclosure provide a chip aging test system, which can reduce the interference of noise generated by the output signal of the heating circuit on the control circuit and improve the accuracy of the chip aging test.

[0006] One aspect of an embodiment of the present disclosure provides a chip aging test system, comprising a control circuit, a signal isolation circuit, and a heating circuit, wherein an output end of the control circuit is connected to an input end of the signal isolation circuit, an input end of the heating circuit is connected to an output end of the signal isolation circuit, the control circuit is grounded via a first grounding line, and the heating circuit is grounded via a second grounding line; The control circuit is configured to output a first control signal, wherein the first control signal represents a duty cycle of an output signal of the heating circuit; The signal isolation circuit is provided with a first photoelectric coupler, the first photoelectric coupler being configured to convert the received first control signal into a first optical signal through a light emitting device, and convert the first optical signal into a second control signal through a photosensitive device; The heating circuit is configured to receive the second control signal and control the on / off of the heating switch based on the second control signal.

[0007] Optionally, in the signal isolation circuit, the output end of the first photoelectric coupler is connected to a first output pull-up power supply via a first output pull-up resistor; When the first photocoupler is turned on, the second control signal output by the signal isolation circuit is at a low level; when the first photocoupler is turned off, the second control signal output by the signal isolation circuit through the first output pull-up resistor is at a high level; The resistance value of the first output pull-up resistor is smaller than a preset resistance value, so that the output current of the signal isolation circuit is larger than a preset current value when the first photoelectric coupler is turned off.

[0008] Optionally, the signal isolation circuit includes a heating feedback signal isolation circuit, the input end of the heating feedback signal isolation circuit is connected to the output end of the heating switch in the heating circuit, and the output end of the heating feedback signal isolation circuit is connected to the control circuit; The heating feedback signal isolation circuit is provided with a second photoelectric coupler, which is used to convert the received heating output signal into a second optical signal through a light-emitting device, and convert the second optical signal into a heating feedback signal through a photosensor; The control circuit is configured to receive the heating feedback signal and generate a heating circuit monitoring result by comparing a waveform of the heating feedback signal with a waveform of the control signal; The heating circuit monitoring result includes one of the following: When the duty cycle of the heating feedback signal is the same as the duty cycle of the first control signal, the monitoring result of the heating circuit is that the heating switch state is normal; When the duty cycle of the heating feedback signal is different from the duty cycle of the first control signal, the heating circuit monitoring result is that the heating switch state is abnormal. When the heating feedback signal continues to be at a low level for more than a first preset time, the heating circuit monitoring result is that the heating switch is short-circuited. When the heating feedback signal continues to be at a high level for more than a second preset time, the heating circuit monitoring result is that the heating switch is open.

[0009] Optionally, the input end of the heating feedback signal isolation circuit is provided with a first voltage dividing resistor and a second voltage dividing resistor; The first voltage-dividing resistor and the second voltage-dividing resistor are connected in series, the anode of the light-emitting device in the second photoelectric coupler is connected to the voltage dividing point between the first voltage-dividing resistor and the second voltage-dividing resistor, and the light-emitting device and the second voltage-dividing resistor are connected in parallel; When the heating output signal causes the voltage across the light emitting device in the second photoelectric coupler to be higher than the optocoupler conduction voltage parameter of the second photoelectric coupler, the second photoelectric coupler is turned on; when the heating output signal causes the voltage across the light emitting device in the second photoelectric coupler to be lower than the optocoupler conduction voltage parameter, the second photoelectric coupler is turned off.

[0010] Optionally, the output end of the second photoelectric coupler in the heating feedback signal isolation circuit is connected to a second output pull-up power supply through a second output pull-up resistor; When the heating output signal is at a high level, the second photoelectric coupler is turned on, and the heating feedback signal output by the heating feedback signal isolation circuit is at a low level. When the heating output signal is at a low level, the second photoelectric coupler is turned off, and the heating feedback signal output by the heating feedback signal isolation circuit is at a high level.

[0011] Optionally, the chip aging test system further includes a power switch and a power monitoring circuit, wherein two ends of the power switch are respectively connected to a heating circuit power supply and the heating circuit; The power monitoring circuit includes at least one monitoring chip and at least two parallel sampling resistors, wherein the two ends of the sampling resistor are respectively connected to the output end of the power switch circuit and the input end of the heating circuit. The monitoring chip is used to detect the actual working voltage value of the heating circuit and the actual working current value of the heating circuit through the sampling resistor, and send an interrupt signal to the control circuit when the actual working voltage value falls within an abnormal voltage value range or the actual working current value falls within an abnormal current value range; The control circuit is configured to send a switch-off signal to the power switch upon receiving the interrupt signal, so as to control the power switch to be turned off.

[0012] Optionally, the signal isolation circuit includes a power monitoring signal isolation circuit, the input end of the power monitoring signal isolation circuit is connected to the output end of the power monitoring circuit, and the output end of the power monitoring signal isolation circuit is connected to the control circuit; The power monitoring signal isolation circuit is provided with an isolation chip, which is used to isolate the clock signal sent from the control circuit to the monitoring chip and the bidirectional digital signal between the control circuit and the monitoring chip; or, At least three third photoelectric couplers are provided in the power supply monitoring signal isolation circuit, and the at least three third photoelectric couplers are respectively used to isolate the clock signal sent by the control circuit to the monitoring chip and the bidirectional digital signal between the control circuit and the monitoring chip.

[0013] Optionally, the heating circuit includes a heating drive circuit and a heating switch circuit; The heating drive circuit includes a push-pull circuit composed of a first transistor and a second transistor, and the push-pull circuit is used to amplify the input current and output the heating drive current to the heating switch circuit; The heating switch circuit includes the heating switch, which is used to close when the received second control signal is at a high level, controlling the heating rod to be powered on for heating, and to close when the received second control signal is at a low level, controlling the heating rod to stop heating.

[0014] Optionally, the heating switch is a MOS tube switch, and the heating switch circuit further includes a drive adjustment circuit and an initial state setting circuit; The drive adjustment circuit includes a drive adjustment resistor, which is connected in series between the signal isolation circuit and the gate of the MOS transistor switch to reduce gate oscillation generated by the gate of the MOS transistor switch; The initial state setting circuit includes an initial state setting resistor, the two ends of which are respectively connected to the gate and source of the MOS transistor switch, and is used to control the MOS transistor switch to be in an off state when the heating switch circuit is powered on.

[0015] Optionally, the heating switch is a MOS tube switch, and the heating switch circuit further includes a filter circuit and a surge absorption circuit; The filter circuit is provided with a ceramic energy storage capacitor, which is connected to the input end of the heating switch and is used to provide instantaneous current when the heating switch is closed and absorb energy released by parasitic inductance when the heating switch is turned off; The surge absorption circuit includes a surge absorption capacitor and a surge absorption resistor connected in series. The surge absorption circuit is connected in parallel with the MOS tube and is used to absorb the surge impact energy generated by the surge pulse voltage. The surge absorption capacitor is connected to the drain of the MOS tube switch, and the surge absorption resistor is connected to the source of the MOS tube switch.

[0016] Based on the embodiment of the present disclosure, a signal isolation circuit is set between the control circuit and the heating circuit, and the first optocoupler in the signal isolation circuit is used to convert the first control signal output by the control circuit into a first optical signal, and then the first optical signal is converted into a second control signal and output to the heating circuit, and the heating switch is controlled to be on and off to achieve the corresponding heating power, thereby realizing electrical signal isolation between the control circuit and the heating circuit. At the same time, the control circuit is grounded through the first grounding line, and the heating circuit is grounded through the second grounding line, so that the grounding lines of the heating circuit and the control circuit are independent of each other and do not interfere with each other. When the heating power is high and the current of the heating circuit output signal is large, the interference of the noise generated by the heating circuit output signal on the control circuit can be reduced, thereby improving the accuracy of the chip aging test.

[0017] The technical solution of the present disclosure is further described in detail below through the accompanying drawings and examples. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the present disclosure and, together with the description, serve to explain the principles of the present disclosure.

[0019] The present disclosure can be more clearly understood from the following detailed description with reference to the accompanying drawings, in which: Figure 1 A schematic structural diagram of a chip aging test system provided by an exemplary embodiment of the present disclosure; Figure 2 A schematic diagram of an FPGA chip in a control circuit provided by an exemplary embodiment of the present disclosure; Figure 3 A schematic diagram of a signal isolation circuit provided by an exemplary embodiment of the present disclosure; Figure 4 A schematic structural diagram of a chip aging test system provided by another exemplary embodiment of the present disclosure; Figure 5 A schematic diagram of a heating feedback signal isolation circuit provided by an exemplary embodiment of the present disclosure; Figure 6 A schematic structural diagram of a chip aging test system provided by another exemplary embodiment of the present disclosure; Figure 7 A schematic diagram of a power monitoring circuit provided by an exemplary embodiment of the present disclosure; Figure 8 A schematic diagram of a power monitoring signal isolation circuit provided by an exemplary embodiment of the present disclosure; Figure 9 Schematic diagram of a push-pull circuit provided by an exemplary embodiment of the present disclosure Figure 10A graph showing the relationship between transistor amplification factor and collector current according to an exemplary embodiment of the present disclosure; Figure 11 A schematic diagram of a heating switch circuit provided by an exemplary embodiment of the present disclosure.

[0020] The reference numerals are as follows: Control circuit 101; signal isolation circuit 102; heating circuit 103; power switch 104; power monitoring circuit 105; heating circuit power supply 106; push-pull circuit 901; heating switch 1101; drive adjustment circuit 1102; initial state setting circuit 1103; filter circuit 1104; surge absorption circuit 1105; First grounding line 1011; control signal isolation circuit 1021; heating feedback signal isolation circuit 1022; power supply monitoring signal isolation circuit 1023; second grounding line 1031. DETAILED DESCRIPTION

[0021] Various exemplary embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. It should be noted that unless otherwise specifically stated, the relative arrangement of components and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present disclosure.

[0022] Those skilled in the art will understand that the terms "first" and "second" in the embodiments of the present disclosure are only used to distinguish different steps, devices or modules, and do not represent any specific technical meanings, nor do they indicate a necessary logical order between them.

[0023] It should also be understood that in the embodiments of the present disclosure, “a plurality of” may refer to two or more than two, and “at least one” may refer to one, two, or more than two.

[0024] It should also be understood that any component, data or structure mentioned in the embodiments of the present disclosure can generally be understood as one or more, unless explicitly limited or otherwise indicated in the context.

[0025] In addition, the term "and / or" in this disclosure is merely a description of the association relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent three situations: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this disclosure generally indicates that the related objects are in an "or" relationship.

[0026] It should also be understood that the description of the various embodiments in this disclosure focuses on the differences between the various embodiments, and the same or similar aspects thereof can be referenced with each other. For the sake of brevity, they will not be described one by one.

[0027] At the same time, it should be understood that for the convenience of description, the sizes of the various parts shown in the drawings are not drawn according to the actual proportional relationship.

[0028] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the present disclosure, its application, or uses.

[0029] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered part of the specification.

[0030] It should be noted that like reference numerals and letters refer to like items in the following figures, and therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0031] Figure 1 This is a schematic diagram of the structure of a chip burn-in test system provided by an exemplary embodiment of the present disclosure. The chip burn-in test system includes a control circuit 101, a signal isolation circuit 102, and a heating circuit 103. The output of the control circuit 101 is connected to the input of the signal isolation circuit 102, and the input of the heating circuit 103 is connected to the output of the signal isolation circuit 102. The control circuit 101 is grounded via a first ground line 1011, and the heating circuit 103 is grounded via a second ground line 1031.

[0032] Specifically, the control circuit 101 is used to output a first control signal, which represents the duty cycle of the output signal of the heating circuit. Schematically, the output signal of the heating circuit 103 is a pulse width modulation (PWM) signal. The duty cycle refers to the ratio of the duration of the high level in a pulse cycle to the duration of the entire cycle. By changing the duty cycle of the PWM signal, different heating powers can be output equivalently. The control circuit 101 can be provided with devices such as a complex programmable logic device (CPLD), a field programmable gate array (FPGA), and a microcontroller unit (MCU) to generate the first control signal based on the chip aging test program. Schematically, Figure 2 A schematic diagram of an FPGA in a control circuit 101 is shown. The FPGA can be connected to the signal isolation circuit 102 through corresponding pins, output a first control signal, and monitor abnormalities of the heating circuit 103 and the power supply by receiving corresponding feedback signals.

[0033] The signal isolation circuit 102 includes a first photocoupler. This first photocoupler is configured to convert a received first control signal into a first optical signal via a light-emitting device, and to convert the first optical signal into a second control signal via a photosensor. When the input end of the first photocoupler receives an electrical signal (i.e., the first control signal output by the control circuit 101), the light-emitting device (e.g., a light-emitting diode) converts the electrical signal into an optical signal (hereinafter referred to as the first optical signal). The photosensor (e.g., a photodiode or phototransistor) generates an electrical signal upon receiving the first optical signal, thereby outputting the second control signal. This utilizes the optical signal as a medium to sever the electrical connection between the control circuit 101 and the heating circuit 103, isolating the control circuit 101 and the heating circuit 103 into two independent circuits. Furthermore, the control circuit 101 is grounded via a first ground line 1011, and the heating circuit 103 is grounded via a second ground line 1031. This isolates the ground lines of the control circuit 101 and the heating circuit 103, preventing interference from the output signal of the heating circuit 103 on the control circuit 101 when the two circuits share a common power supply ground system.

[0034] The heating circuit 103 is configured to receive a second control signal and control the on and off of the heating switch based on the second control signal.

[0035] The heating circuit 103 controls the on and off of the heating switch based on the second control signal. For example, when the second control signal is high, the heating switch is controlled to close to power on the heating device for heating; when the second control signal is low, the heating switch is controlled to close to power off the heating device.

[0036] Based on the embodiment of the present disclosure, a signal isolation circuit is set between the control circuit and the heating circuit, and the first optocoupler in the signal isolation circuit is used to convert the first control signal output by the control circuit into a first optical signal, and then the first optical signal is converted into a second control signal and output to the heating circuit, and the heating switch is controlled to be on and off to achieve the corresponding heating power, thereby realizing electrical signal isolation between the control circuit and the heating circuit. At the same time, the control circuit is grounded through the first grounding line, and the heating circuit is grounded through the second grounding line, so that the grounding lines of the heating circuit and the control circuit are independent of each other and do not interfere with each other. When the heating power is high and the current of the heating circuit output signal is large, the interference of the noise generated by the heating circuit output signal on the control circuit can be reduced, thereby improving the accuracy of the chip aging test.

[0037] In one possible implementation, in the signal isolation circuit 102, the output end of the first photocoupler is connected to the first output pull-up power supply via a first output pull-up resistor. When the first photocoupler is on, the second control signal output by the signal isolation circuit 102 is a low level. When the first photocoupler is off, the second control signal output by the signal isolation circuit 102 via the first output pull-up resistor is a high level. The resistance value of the first output pull-up resistor is less than a preset resistance value, so that the output current of the signal isolation circuit 102 is greater than the preset current value when the first photocoupler is off.

[0038] The first output pull-up power supply is used to power the photosensor in the first optocoupler. When the first control signal is at a high level, the light-emitting device in the first optocoupler generates a first optical signal, the first optocoupler turns on to generate current, and the output of the signal isolation circuit 102 is pulled down to a low level. When the first control signal is at a low level, the light-emitting device in the first optocoupler does not generate the first optical signal, the first optocoupler turns off, and the first output pull-up power supply pulls the output of the signal isolation circuit 102 up to a high level. Furthermore, by setting a reasonable first output pull-up resistor, the output current of the signal isolation circuit 102 can be controlled. For example, since the current output by the signal isolation circuit 102 is ultimately used to drive the heating switch, if the heating switch opens and closes slowly or the on-resistance of the heating switch is too large, it will cause high losses in the heating switch itself and may even cause the heating switch to overheat and be damaged. Therefore, setting an output pull-up resistor with a smaller resistance to amplify the output current can improve the driving capability of the signal isolation circuit 102 and the response speed of the heating switch, thereby reducing the loss of the heating switch. At the same time, the resistance of the first output pull-up resistor is greater than the preset minimum resistance to avoid excessive power consumption of the first output pull-up resistor due to excessive output current.

[0039] Indicative, Figure 3 A schematic diagram of a signal isolation circuit 102 is shown. As shown, the output of the first optocoupler U27C is connected to a 48V first output pull-up power supply via four first output pull-up resistors R498, R499, R504, and R508. The forward operating voltage (VF) of the first optocoupler U27C is 1.2V, and the high level of the first control signal FPGA_HEATER_PWM output by the control circuit 101 is 3.3V. When the first optocoupler U27C is on, the input current of the signal isolation circuit 102 is (3.3V - 1.2V) / 200Ω = 10.5mA. The first output pull-up resistors utilize four 4KΩ resistors in 0805 packages (connected in series and then in parallel as shown in the figure, resulting in an equivalent resistance of 4.02KΩ). When the first optocoupler is off, a 48V pull-up drive capability is achieved, and the output current is approximately 11.94mA.

[0040] In one possible implementation, Figure 4 As shown, the first optocoupler, the first output pull-up resistor, and the first output pull-up power supply in the above embodiment constitute the control signal isolation circuit 1021 in the signal isolation circuit 102. The signal isolation circuit 102 also includes a heating feedback signal isolation circuit 1022. The input end of the heating feedback signal isolation circuit 1022 is connected to the output end of the heating switch in the heating circuit 103, and the output end of the heating feedback signal isolation circuit 1022 is connected to the control circuit 101. If a circuit fault occurs in a high-power circuit, it is easy to cause the test board and the chip under test to burn out. The heating feedback signal isolation circuit 1022 in the embodiment of the present disclosure can feed back the heating output signal output by the heating circuit 103 to the control circuit 101, so that the control circuit 101 can monitor whether the output signal of the heating circuit 103 is normal, thereby realizing abnormal monitoring of the heating circuit.

[0041] Optionally, a second optocoupler is provided in the heating feedback signal isolation circuit 1022. This second optocoupler is used to convert the received heating output signal into a second optical signal via a light-emitting device, and to convert the second optical signal into a heating feedback signal via a photosensor. While feeding back the heating output signal to the control circuit 101, the heating feedback signal isolation circuit 1022 uses an optocoupler to isolate the heating output signal, thereby ensuring electrical isolation between the control circuit 101 and the heating circuit 103.

[0042] The control circuit 101 is configured to receive a heating feedback signal and generate a heating circuit monitoring result by comparing the waveform of the heating feedback signal with the waveform of the control signal. The heating circuit monitoring result includes one of the following: When the duty cycle of the heating feedback signal is the same as the duty cycle of the first control signal, the heating circuit monitoring result indicates that the heating switch state is normal; When the duty cycle of the heating feedback signal is different from the duty cycle of the first control signal, the heating circuit monitoring result is that the heating switch state is abnormal; wherein, when the heating feedback signal continues to be at a low level for a period exceeding the first preset time, the heating circuit monitoring result is that the heating switch is short-circuited; when the heating feedback signal continues to be at a high level for a period exceeding the second preset time, the heating circuit monitoring result is that the heating switch is open.

[0043] Because the high and low levels of the first control signal and the second control signal are opposite, that is, the high and low levels of the first control signal and the heating output signal are opposite, when the heating output signal undergoes photoelectric signal conversion through the second optocoupler, the high and low levels of the heating output signal and the heating feedback signal are again opposite. Therefore, under normal circumstances, the duty cycle of the first control signal and the heating feedback signal should be consistent. When the duty cycle of the heating feedback signal differs from the duty cycle of the first control signal, the heating circuit monitoring result indicates that the heating switch state is abnormal. The control circuit 101 can stop outputting the first control signal or directly control the power switch to be turned off, and generate an abnormality alarm information.

[0044] In one possible embodiment, the input end of the heating feedback signal isolation circuit 1022 is provided with a first voltage-dividing resistor and a second voltage-dividing resistor; the first voltage-dividing resistor and the second voltage-dividing resistor are connected in series, the anode of the light-emitting device in the second photoelectric coupler is connected to the voltage-dividing point between the first voltage-dividing resistor and the second voltage-dividing resistor, and the light-emitting device is connected in parallel with the second voltage-dividing resistor.

[0045] When the heating output signal causes the voltage across the light emitter in the second photocoupler to exceed the optocoupler conduction voltage parameter of the second photocoupler, the second photocoupler is turned on; when the heating output signal causes the voltage across the light emitter in the second photocoupler to fall below the optocoupler conduction voltage parameter, the second photocoupler is turned off. By providing a voltage divider resistor, the heating output signal does not need to drop below the optocoupler conduction voltage parameter to cause the second photocoupler to be turned off. This prevents the high-power heating circuit from outputting a high-level heating output signal that fails to trigger the second photocoupler to turn off, resulting in the control circuit 101 being unable to detect the output shutdown and an erroneous detection result.

[0046] Indicative, Figure 5 FIG. 1 shows a schematic diagram of a heating feedback signal isolation circuit 1022. Figure 5 As shown, the optocoupler conduction voltage parameter VE of the second optocoupler U30A is 1.2V. The heating output signal HEATER_CTRL is divided by a first voltage-dividing resistor R672 of 30KΩ and a second voltage-dividing resistor R1235 of 2KΩ. When the voltage across the second optocoupler U30A is higher than the optocoupler conduction voltage parameter 1.2V, the voltage of the heating output signal is 20V. That is, as long as the voltage of the heating output signal is lower than 20V, the second optocoupler U30A will be cut off, thereby adjusting the high and low level judgment thresholds of the heating output signal. If the voltage-dividing resistor is not provided, the voltage of the heating output signal needs to be lower than 1.2V for the control circuit 101 to detect a low level. However, the low level of the heating output signal output by a high-power heating circuit is usually higher, which can easily lead to false detection.

[0047] In one possible embodiment, the output end of the second optocoupler in the heating feedback signal isolation circuit is connected to the second output pull-up power supply via a second output pull-up resistor. When the heating output signal is high, the second optocoupler is turned on, and the heating feedback signal output by the heating feedback signal isolation circuit is low. When the heating output signal is low, the second optocoupler is turned off, and the heating feedback signal output by the heating feedback signal isolation circuit is high.

[0048] Indicative, such as Figure 5 As shown, the resistance values ​​of the first voltage divider resistor, the second voltage divider resistor and the second output pull-up resistor need to match. Figure 5 The second output pull-up power supply shown is 3.3V, and the second output pull-up resistor is composed of a 4.7KΩ resistor R668 and a 100Ω resistor R673 connected in series, with an equivalent resistance value of 4.8KΩ. The output drive current of the second optocoupler is approximately 0.7mA, and the current transfer ratio (CTR) parameter of the second optocoupler is 50% to 60%. The current value range of the input current of the second optocoupler is approximately 0.11mA to 1.4mA. Based on this current value range and the voltage value of the output signal of the heating circuit, the appropriate voltage divider resistor value can be calculated.

[0049] Based on the embodiment of the present disclosure, by setting a voltage divider resistor at the input end of the heating feedback signal isolation circuit 1022, the judgment threshold of the high and low levels of the heating output signal is improved, which can improve the accuracy of heating circuit monitoring and avoid false detection caused by the low level not being recognized.

[0050] In one possible implementation, Figure 6 As shown, the chip aging test system further includes a power switch 104 and a power monitoring circuit 105 . Two ends of the power switch 104 are connected to a heating circuit power supply 106 and a heating circuit 103 , respectively.

[0051] Indicative, such as Figure 7As shown, the power monitoring circuit 105 includes at least one monitoring chip and at least two parallel-connected sampling resistors (R729 and R731). The two ends of the sampling resistors are connected to the output of the power switch circuit and the input of the heating circuit 103, respectively. The monitoring chip is used to detect the actual operating voltage of the heating circuit 103 and the actual operating current of the heating circuit 103 through the sampling resistors. For example, the monitoring chip directly detects the voltage across the heating circuit 103 and calculates the actual operating current of the heating circuit 103 based on the voltage across the sampling resistors and the resistance of the sampling resistors. When the actual operating voltage falls within an abnormal voltage range or the actual operating current falls within an abnormal current range, the monitoring chip sends an interrupt signal to the control circuit 101. Upon receiving the interrupt signal, the control circuit 101 sends a switch-off signal to the power switch 104 to turn off the power switch 104. The monitoring chip sends the interrupt signal to the control circuit 101 via an Inter-Integrated Circuit (IIC) bus interface and the IIC bus. Simultaneously, the control circuit 101 can send upper and lower threshold values ​​corresponding to the abnormal current range to the monitoring chip via the IIC bus.

[0052] Optionally, when there is at least one heating circuit 103, a monitoring chip can be set for each heating circuit 103, or a monitoring chip can be set for each heating circuit 103 corresponding to the chip under test. The embodiment of the present disclosure does not limit the correspondence between the monitoring chip and the heating circuit 103.

[0053] In one possible implementation, Figure 6 As shown, the signal isolation circuit 102 further includes a power monitoring signal isolation circuit 1023 , the input end of the power monitoring signal isolation circuit 1023 is connected to the output end of the power monitoring circuit 105 , and the output end of the power monitoring signal isolation circuit 1023 is connected to the control circuit 101 .

[0054] The power monitoring signal isolation circuit 1023 can use an isolation chip (such as an IIC isolation chip) or an optocoupler for electrical signal isolation. That is, the power monitoring signal isolation circuit is provided with an isolation chip, and the isolation chip is used to isolate the clock signal sent by the control circuit 101 to the monitoring chip and the bidirectional digital signal between the control circuit 101 and the monitoring chip; or, the power monitoring signal isolation circuit is provided with at least three third optocouplers, and the at least three third optocouplers are used to isolate the clock signal sent by the control circuit 101 to the monitoring chip and the bidirectional digital signal between the control circuit 101 and the monitoring chip. Among them, the bidirectional digital signal includes the interrupt signal sent by the monitoring chip to the control circuit 101 and the threshold adjustment signal sent by the control circuit 101 to the monitoring chip (a digital signal used to update the upper and lower threshold values ​​corresponding to the abnormal current value interval).

[0055] Indicative, Figure 8 A schematic diagram of a power monitoring signal isolation circuit 1023 using an optocoupler to implement electrical signal isolation is shown. Figure 8 The three groups of isolation circuits from top to bottom are respectively used to isolate the clock signal sent from the control circuit 101 to the monitoring chip, the digital signal sent from the control circuit 101 to the monitoring chip, and the digital signal sent from the monitoring chip to the control circuit 101.

[0056] Based on the embodiment of the present disclosure, by setting up a power supply monitoring circuit 105, the working voltage monitoring and working current monitoring of the high-power heating circuit are realized. When the actual working voltage value belongs to the abnormal voltage value range or the actual working current value belongs to the abnormal current value range, the power switch is controlled to be turned off to avoid damage to the chip under test due to circuit failure. At the same time, a power supply monitoring signal isolation circuit 1023 is set between the power supply monitoring circuit 105 and the control circuit 101 to ensure electrical isolation between the control circuit 101 and the power supply monitoring circuit 105 and the heating circuit 103.

[0057] In a possible implementation, the heating circuit 103 includes a heating drive circuit and a heating switch circuit.

[0058] The heating drive circuit includes a push-pull circuit composed of a first transistor and a second transistor, and the push-pull circuit is used to amplify the input current and output the heating drive current to the heating switch circuit. Figure 9 FIG. 9 is a schematic diagram showing a push-pull circuit. The push-pull circuit 901 includes an NPN transistor T12 and a PNP transistor T15. The relationship between the transistor gain hFE and the collector current Ic is shown in FIG. Figure 10 As shown, the maximum input current Ib of the push-pull circuit is approximately 2 mA, and the maximum output current Ic of the push-pull circuit is approximately 140 mA.

[0059] The heating switch circuit includes a heating switch, which is used to close when the received second control signal is at a high level to control the heating rod to be powered on for heating, and to close when the received second control signal is at a low level to control the heating rod to stop heating.

[0060] Optional, Figure 11A schematic diagram of a heating switch circuit is shown, wherein heating switch 1101 is a MOS transistor switch. The heating switch circuit also includes a drive regulation circuit 1102 and an initial state setting circuit 1103. As an example, since heating switch 1101 is turned on by a negative voltage Vgs (i.e., the voltage between gate G and source S), a PMOS transistor switch is selected as heating switch 1101. When selecting heating switch 1101, consideration should be given to choosing a model with low on-resistance, low parasitic capacitance, high voltage withstand (e.g., voltage withstand capability greater than 48V), and strong drain current Id flow capacity (e.g., operating current output supporting currents exceeding 30A). Low on-resistance and low parasitic capacitance can reduce conduction and switching losses of heating switch 1101.

[0061] The drive adjustment circuit 1102 includes a drive adjustment resistor connected in series between the signal isolation circuit 102 and the gate of the MOS transistor switch to reduce gate oscillations generated by the gate of the MOS transistor switch. Because the parasitic inductance of the MOS transistor switch and the common-gate amplifier may generate LC oscillations, adding a drive adjustment resistor (e.g., a 33Ω resistor) can provide damping for the heating circuit 103 and reduce Vgs oscillations.

[0062] Initial state setting circuit 1103 includes an initial state setting resistor, the two ends of which are connected to the gate and source of the MOS transistor switch, respectively. This resistor is used to control the MOS transistor switch to be in the off state when the heating switch circuit is powered on. By placing an initial state setting resistor (e.g., an 11 kΩ resistor) between the gate and source of the MOS transistor switch, a default state can be set when the circuit is uncontrollable upon power-on startup. The G terminal of the MOS transistor switch is pulled up to the S terminal via the initial state setting resistor, ensuring that the voltages of the G and S terminals are consistent during power-on and power-off cycles. This maintains the MOS transistor switch in the off state during power-on, preventing abnormal power output from the MOS transistor switch.

[0063] In addition, the heating switch circuit also includes a filter circuit 1104 and a surge absorption circuit 1105. A ceramic energy storage capacitor is provided in the filter circuit 1104 and is connected to the input end of the heating switch 1101. The ceramic energy storage capacitor is used to provide instantaneous current when the heating switch 1101 is closed and absorb the energy released by the parasitic inductance when the heating switch 1101 is turned off. During the high-speed switching process of the MOS tube switch, there are high requirements for the instantaneous current change of the input power supply. Therefore, a sufficiently large ceramic energy storage capacitor needs to be provided at the input end of the MOS tube switch to meet the high current demand of the heating rod when the MOS tube switch is turned on, and to absorb the impact energy caused by the parasitic inductance when the MOS tube switch is turned off.

[0064] The surge absorption circuit 1105 includes a surge absorption capacitor and a surge absorption resistor connected in series. The surge absorption circuit is connected in parallel with the MOS transistor switch to absorb the surge impact energy generated by the surge pulse voltage, wherein the surge absorption capacitor is connected to the drain of the MOS transistor switch, and the surge absorption resistor is connected to the source of the MOS transistor switch. The circuit of the D pole or S pole of the MOS transistor switch has parasitic inductance. At the moment of the MOS transistor switch being turned off, a surge pulse voltage may appear on the D pole and S pole. If the surge pulse voltage exceeds the maximum voltage allowed by the MOS transistor switch, it will damage the MOS transistor switch. Therefore, a uF capacitor and a KΩ resistor are added between the D pole and the S pole to absorb the surge impact energy. The capacitance value of the surge absorption capacitor and the resistance value of the surge absorption resistor can be adjusted according to actual test requirements.

[0065] Based on the embodiments of the present disclosure, by providing a drive adjustment circuit 1102, an initial state setting circuit 1103, a filter circuit 1104 and a surge absorption circuit 1105 in the heating circuit 103, the loss of the MOS tube switch can be reduced, the MOS tube switch can be ensured to be in the off state during the power-on process to avoid abnormal power output, the impact energy caused by parasitic inductance at the moment of turning off the MOS tube switch can be absorbed, and the surge impact energy can be absorbed. This can reduce the probability of abnormalities in the heating circuit, thereby improving the safety and test efficiency of the chip aging test.

Claims

1. A chip aging test system, characterized in that: The device comprises a control circuit, a signal isolation circuit and a heating circuit, wherein the output end of the control circuit is connected to the input end of the signal isolation circuit, the input end of the heating circuit is connected to the output end of the signal isolation circuit, the control circuit is grounded via a first grounding line, and the heating circuit is grounded via a second grounding line; The control circuit is configured to output a first control signal, wherein the first control signal represents a duty cycle of an output signal of the heating circuit; The signal isolation circuit is provided with a first photoelectric coupler, the first photoelectric coupler being configured to convert the received first control signal into a first optical signal through a light emitting device, and convert the first optical signal into a second control signal through a photosensitive device; The heating circuit is configured to receive the second control signal and control the on / off of the heating switch based on the second control signal.

2. The system according to claim 1, wherein: In the signal isolation circuit, the output end of the first photoelectric coupler is connected to the first output pull-up power supply through the first output pull-up resistor; When the first photocoupler is turned on, the second control signal output by the signal isolation circuit is at a low level; when the first photocoupler is turned off, the second control signal output by the signal isolation circuit through the first output pull-up resistor is at a high level; The resistance value of the first output pull-up resistor is smaller than a preset resistance value, so that the output current of the signal isolation circuit is larger than a preset current value when the first photoelectric coupler is turned off.

3. The system according to claim 1, wherein: The signal isolation circuit includes a heating feedback signal isolation circuit, the input end of the heating feedback signal isolation circuit is connected to the output end of the heating switch in the heating circuit, and the output end of the heating feedback signal isolation circuit is connected to the control circuit; The heating feedback signal isolation circuit is provided with a second photoelectric coupler, which is used to convert the received heating output signal into a second optical signal through a light-emitting device, and convert the second optical signal into a heating feedback signal through a photosensor; The control circuit is configured to receive the heating feedback signal and generate a heating circuit monitoring result by comparing a waveform of the heating feedback signal with a waveform of the control signal; The heating circuit monitoring result includes one of the following: When the duty cycle of the heating feedback signal is the same as the duty cycle of the first control signal, the monitoring result of the heating circuit is that the heating switch state is normal; When the duty cycle of the heating feedback signal is different from the duty cycle of the first control signal, the heating circuit monitoring result is that the heating switch state is abnormal. When the heating feedback signal continues to be at a low level for more than a first preset time, the heating circuit monitoring result is that the heating switch is short-circuited. When the heating feedback signal continues to be at a high level for more than a second preset time, the heating circuit monitoring result is that the heating switch is open.

4. The system according to claim 3, characterized in that The input end of the heating feedback signal isolation circuit is provided with a first voltage dividing resistor and a second voltage dividing resistor; The first voltage-dividing resistor and the second voltage-dividing resistor are connected in series, the anode of the light-emitting device in the second photoelectric coupler is connected to the voltage dividing point between the first voltage-dividing resistor and the second voltage-dividing resistor, and the light-emitting device and the second voltage-dividing resistor are connected in parallel; When the heating output signal causes the voltage across the light emitting device in the second photoelectric coupler to be higher than the optocoupler conduction voltage parameter of the second photoelectric coupler, the second photoelectric coupler is turned on; when the heating output signal causes the voltage across the light emitting device in the second photoelectric coupler to be lower than the optocoupler conduction voltage parameter, the second photoelectric coupler is turned off.

5. The system according to claim 3, wherein: The output end of the second photoelectric coupler in the heating feedback signal isolation circuit is connected to the second output pull-up power supply through a second output pull-up resistor; When the heating output signal is at a high level, the second photoelectric coupler is turned on, and the heating feedback signal output by the heating feedback signal isolation circuit is at a low level. When the heating output signal is at a low level, the second photoelectric coupler is turned off, and the heating feedback signal output by the heating feedback signal isolation circuit is at a high level.

6. The system according to claim 1, wherein: The chip aging test system further includes a power switch and a power monitoring circuit, wherein two ends of the power switch are respectively connected to a heating circuit power supply and the heating circuit; The power monitoring circuit includes at least one monitoring chip and at least two parallel sampling resistors, wherein the two ends of the sampling resistor are respectively connected to the output end of the power switch circuit and the input end of the heating circuit. The monitoring chip is used to detect the actual working voltage value of the heating circuit and the actual working current value of the heating circuit through the sampling resistor, and send an interrupt signal to the control circuit when the actual working voltage value falls within an abnormal voltage value range or the actual working current value falls within an abnormal current value range; The control circuit is configured to send a switch-off signal to the power switch upon receiving the interrupt signal, so as to control the power switch to be turned off.

7. The system according to claim 6, characterized in that The signal isolation circuit includes a power monitoring signal isolation circuit, the input end of the power monitoring signal isolation circuit is connected to the output end of the power monitoring circuit, and the output end of the power monitoring signal isolation circuit is connected to the control circuit; The power monitoring signal isolation circuit is provided with an isolation chip, which is used to isolate the clock signal sent from the control circuit to the monitoring chip and the bidirectional digital signal between the control circuit and the monitoring chip; or, At least three third photoelectric couplers are provided in the power supply monitoring signal isolation circuit, and the at least three third photoelectric couplers are respectively used to isolate the clock signal sent by the control circuit to the monitoring chip and the bidirectional digital signal between the control circuit and the monitoring chip.

8. The system according to any one of claims 1 to 7, characterized in that: The heating circuit includes a heating drive circuit and a heating switch circuit; The heating drive circuit includes a push-pull circuit composed of a first transistor and a second transistor, and the push-pull circuit is used to amplify the input current and output the heating drive current to the heating switch circuit; The heating switch circuit includes the heating switch, which is used to close when the received second control signal is at a high level, controlling the heating rod to be powered on for heating, and to close when the received second control signal is at a low level, controlling the heating rod to stop heating.

9. The system according to claim 8, characterized in that The heating switch is a MOS tube switch, and the heating switch circuit further includes a drive adjustment circuit and an initial state setting circuit; The drive adjustment circuit includes a drive adjustment resistor, which is connected in series between the signal isolation circuit and the gate of the MOS transistor switch to reduce gate oscillation generated by the gate of the MOS transistor switch; The initial state setting circuit includes an initial state setting resistor, the two ends of which are respectively connected to the gate and source of the MOS transistor switch, and is used to control the MOS transistor switch to be in an off state when the heating switch circuit is powered on.

10. The system according to claim 8, wherein: The heating switch is a MOS tube switch, and the heating switch circuit also includes a filter circuit and a surge absorption circuit; The filter circuit is provided with a ceramic energy storage capacitor, which is connected to the input end of the heating switch and is used to provide instantaneous current when the heating switch is closed and absorb energy released by parasitic inductance when the heating switch is turned off; The surge absorption circuit includes a surge absorption capacitor and a surge absorption resistor connected in series. The surge absorption circuit is connected in parallel with the MOS tube and is used to absorb the surge impact energy generated by the surge pulse voltage. The surge absorption capacitor is connected to the drain of the MOS tube switch, and the surge absorption resistor is connected to the source of the MOS tube switch.

Images