Test circuit and test method for measuring OS and function of integrated circuit

Abstract

The invention discloses a test circuit and test method for measuring the OS and function of an integrated circuit, and the circuit comprises an MCU control module which is used for executing a test program and data communication; the function test module comprises a Loadboard module and a peripheral circuit switching unit, the Loadboard module is used for bearing a tested IC and providing a function test interface, and the peripheral circuit switching unit switches connection between a pin of the tested IC and a peripheral circuit or connection between the pin of the tested IC and the peripheral circuit or connection between the pin of the tested IC and the peripheral circuit in a suspended state through a relay group; and the OS test module is connected with the function test module and is used for executing an OS test.

Description

Technical Field

[0001] The present invention relates to the field of chip testing, and in particular to a test circuit and a test method for measuring the OS and function of an integrated circuit. Background Art

[0002] In the field of integrated circuit (IC) testing, open circuit / short circuit (OS) testing and functional testing are the core links to ensure chip reliability.

[0003] The current mainstream IC testers (such as automatic test equipment ATE) usually use application-specific integrated circuits (ASIC) or high-precision current source chips to implement OS test functions. The hardware structure is complex and expensive (usually more than several million yuan). In addition, such equipment must be operated by professional test engineers, which further increases the threshold for use and maintenance costs.

[0004] In high / low temperature environment testing, existing Handler systems (such as the Exceed series) rely on external temperature sensors on the Nest fixture for temperature control. Their temperature index is ±3°C, but they lack effective means to directly obtain the actual junction temperature (TJ) inside the chip, resulting in an open-loop temperature control system and an inability to dynamically calibrate the deviation between the ambient temperature and the actual chip temperature.

[0005] Traditional OS test equipment needs to inject a constant current into the pin of the device under test (DUT) through a professional current output chip, and measure the voltage difference through a complex circuit to determine the open / short circuit state. This type of solution not only has high hardware costs, but also has a cumbersome test process, making it difficult to quickly verify the flatness of the test area Nest and Socket, affecting test consistency and reliability.

[0006] Existing test systems usually integrate OS testing and functional testing into a single device, resulting in hardware redundancy and low switching efficiency. For example, when functional testing requires configuring peripheral circuits for the chip under test, the hardware connection needs to be manually adjusted, which is time-consuming and prone to human errors. Summary of the invention

[0007] To achieve the above-mentioned purpose and other related purposes, the present invention discloses a test circuit for measuring the OS and function of an integrated circuit, comprising: MCU control module, used for executing test programs and data communication; The functional test module includes a Loadboard module and a peripheral circuit switching unit. The Loadboard module is used to carry the IC under test and provide a functional test interface. The peripheral circuit switching unit switches the connection between the pin of the IC under test and the peripheral circuit or the suspended state through a relay group. An OS test module, connected to the functional test module, for performing OS testing; The OS test module is composed of the mirror constant current source circuit, relay switching circuit and absolute value voltage conversion circuit in the functional test module; The mirror image constant current source circuit is configured to output positive and negative currents of fixed values; The relay switching circuit is used to apply the positive and negative currents to the designated pins of the IC under test; The absolute value voltage conversion circuit converts the positive and negative voltages generated by the positive and negative currents flowing through the IC under test into positive voltage signals, and collects the signals through the ADC interface of the MCU control module to determine the OS status.

[0008] Furthermore, the relay group of the functional test module is controlled by a shift chip driving circuit, and the MCU control module is connected to the IC under test through an IIC communication protocol to obtain its internal temperature data.

[0009] Furthermore, the mirror image constant current source circuit includes a self-checking function module for detecting the output state of the constant current source in real time.

[0010] Furthermore, the relay switching circuit adopts a G6K model relay with a 24V control voltage, whose action time is less than 10 milliseconds and the driving current is less than 10 mA.

[0011] Furthermore, the absolute value voltage conversion circuit includes a full-wave rectifier circuit or an absolute value amplifier, which is used to convert positive and negative voltage signals into positive voltage signals.

[0012] Furthermore, the MCU control module includes: IIC communication interface, used to communicate with the IC under test and the temperature measurement chip on the Loadboard; The shift chip communication interface is used to drive the relay group to achieve test mode switching.

[0013] Furthermore, the OS test module and the functional test module are configured independently of each other, supporting separate or simultaneous execution of OS test and functional test.

[0014] Furthermore, the test circuit obtains the actual junction temperature of the IC under test through the protocol interface, and feeds it back to the Handler system to form a temperature control closed loop.

[0015] Furthermore, the relay group of the Loadboard module is configured to automatically disconnect from the IC pins after the test is completed to prevent voltage breakdown.

[0016] In another aspect, the present invention provides an IC testing method for a test circuit, comprising the following steps: Place the IC under test in the test position of the Loadboard module; Select OS test or functional test mode through MCU control module; If OS test is selected, positive and negative currents are output to the pins of the IC under test through a mirror constant current source, and the converted voltage signal is collected to determine the open circuit / short circuit status; If the functional test is selected, the peripheral circuit is provided to the IC under test through relay switching, and its internal temperature data is read through the IIC protocol; After completing the test, disconnect all relay connections and remove the IC under test.

[0017] By adopting the above technical solution, the entire test function uses three modules, namely the MCU control module for placing the driver, the Loadboard module for placing the test chip for functional testing, and the OS module for supporting OS testing. Its cost is much lower than the test machines on the market that cost millions of dollars, eliminating the need for expensive test equipment, and without the need for professional test engineers to operate, the performance of the Handler can be quickly verified. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The above and other features, advantages and aspects of the embodiments of the present disclosure will become more apparent with reference to the following detailed description in conjunction with the accompanying drawings. The accompanying drawings are used to better understand the present solution and do not constitute a limitation of the present disclosure. In the accompanying drawings, the same or similar reference numerals represent the same or similar elements, among which: Figure 1 It is a functional test module diagram of the present invention; Figure 2 It is the OS test module diagram of the present invention; Figure 3 It is the MCU control module diagram of the present invention. DETAILED DESCRIPTION

[0019] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0020] Reference Figure 1 , Figure 2 and Figure 3 , an embodiment of the present invention provides a test circuit for measuring the OS and function of an integrated circuit, including: MCU control module, used to execute test programs and data communication, including ADC acquisition interface, IIC communication interface, shift chip communication interface and power input interface.

[0021] The functional test module includes a Loadboard module and a peripheral circuit switching unit. The Loadboard module is used to carry the IC under test and provide a functional test interface. The peripheral circuit switching unit switches the connection between the IC pin under test and the peripheral circuit or the suspended state through a relay group.

[0022] The OS test module is connected to the functional test module and is used to perform OS testing.

[0023] Among them, the functional test module also includes a voltage-stabilized power supply and a shift chip. The voltage-stabilized power supply adopts 24V input, Fuse protection, anti-reverse connection protection, and 24V, ±5V, and ±3.3V output. The shift chip is connected to the relay group through a photoelectric isolation drive group. The relay group is linked to the chip's minimum system working circuit. The chip under test is connected to the relay group through the SOCKET on the functional test module.

[0024] The OS test module includes a shift chip, a power input interface, a ±100uA current source input, and a relay group.

[0025] As mentioned above, the voltage-stabilized power supply part outputs the corresponding power supply to supply each part of the driving circuit; the ±100uA mirror constant current source part is for OS detection, providing a relatively stable and cheap current source. The current source has a self-test function, which can detect whether its state is normal. When the ± current source flows through the upper tube or lower tube of the load, it will produce a certain voltage drop, which is converted into a positive voltage that can be detected by the MCU module ADC through the absolute value voltage conversion circuit; when there is a chip under test in the SOCKET, the relay group of the functional test module provides the possibility of freely selecting it to do OS testing, functional testing or pin suspension, and its relay group is driven by the shift chip to select the corresponding relay to open / close; the current self-test circuit, relay switch indicator light, etc., increase the detection degree when there is a problem, and quickly locate the problem.

[0026] The power input interface obtains power from the functional test module so that each drive circuit can be powered; the ±100uA current source input can be applied to the corresponding pin of the chip under test through the relay group, and compared with the chip parameters to determine whether an OS abnormality has occurred. The relay group is driven by the shift chip to select the corresponding relay to open / close; the relay switch indicator light increases the detection degree when a problem occurs and quickly locates the problem.

[0027] The ADC acquisition interface is used to detect the positive and negative current states and the OS state; the IIC communication is used to communicate with the IC under test and the temperature measurement chip on the Loadboard; the shift chip communication interface is used to drive the relay group for functional testing and OS testing; The functional test module and the OS test module are independent of each other. You can select one test or all tests.

[0028] When the OS needs to be tested, the MCU controls the OS module to switch the current source to the pin of the chip under test. The current flows through the upper and lower diodes inside the chip under test to generate voltage. Through the absolute value voltage conversion circuit, the detected measurement voltage is converted into a positive voltage for ADC collection.

[0029] When a test function is required, the MCU controls the functional test module to apply the minimum system circuit around the chip under test to the pins of the chip under test, and the MCU obtains the measurement data of the chip under test through the IIC protocol.

[0030] By collecting the internal temperature of the chip under test and analyzing the factors that affect the temperature consistency between the various sites of the equipment, the temperature control accuracy of the Handler system can be further improved.

[0031] The OS test items can verify the flatness of the test area Nest and socket; when the Handler controls the temperature, the functional test items can obtain the actual TJ temperature inside the chip through the protocol, effectively realizing the temperature control closed loop of the Handler.

[0032] In order to reliably switch various test functions to IC pins, all relays are in direct contact with IC pins. The G6K relay with a control voltage of 24V is selected here; its action time is fast, only a few milliseconds, and it can switch to the corresponding working mode very quickly; it consumes less current, only a few milliamperes are needed to drive, and 24V power supply is more common in the market.

[0033] The material cost is much lower than the price of existing test machines in the market, meeting the demand for Handler performance testing at a lower cost.

[0034] The entire test function uses three modules, namely the MCU control module for placing the driver, the Loadboard module for placing the test chip for functional testing, and the OS module for supporting OS testing. Its cost is much lower than the test machines on the market that cost millions of dollars, eliminating the need for expensive test equipment and requiring no professional test engineers to operate, and the performance of the Handler can be quickly verified.

[0035] After placing the IC on the "Loadboard module", you can open the corresponding test function through the "MCU control module" for testing; when the OS module is installed, you can choose whether to perform the OS test. After the test is completed, you can separate all loads and remove the IC to reduce its contact and separation voltage to prevent breakdown of the IC under test.

[0036] OS test principle: Generate fixed positive and negative currents through a mirror constant current source, then switch the corresponding relay pins to apply the positive and negative currents to the corresponding DUT; convert the positive and negative voltages generated by the positive and negative currents flowing through the load into fixed positive voltages through a voltage absolute value conversion circuit, and read the corresponding voltage through an ADC to determine the OS (Open-Short) of the current measurement PIN. The structure is simple and clear, and the cost is low.

[0037] Functional test principle: switch the corresponding relay pin, add the peripheral circuit required by the chip under test to the corresponding PIN, and obtain the corresponding data through the MCU module.

[0038] The present invention also provides an IC testing method for a test circuit, comprising the following steps: Place the IC under test in the test position of the Loadboard module; Select OS test or functional test mode through MCU control module; If OS test is selected, positive and negative currents are output to the pins of the IC under test through a mirror constant current source, and the converted voltage signal is collected to determine the open circuit / short circuit status; If the functional test is selected, the peripheral circuit is provided to the IC under test through relay switching, and its internal temperature data is read through the IIC protocol; After completing the test, disconnect all relay connections and remove the IC under test.

[0039] Those skilled in the art will appreciate that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as those generally understood by those skilled in the art in the art to which the present invention belongs. It should also be understood that terms such as those defined in general dictionaries should be understood to have meanings consistent with the meanings in the context of the prior art, and will not be interpreted with idealized or overly formal meanings unless specifically defined.

[0040] For the method embodiments, for the sake of simplicity, they are all described as a series of action combinations, but those skilled in the art should know that the embodiments of the present invention are not limited by the order of the actions described, because according to the embodiments of the present invention, some steps can be performed in other orders or simultaneously. Secondly, those skilled in the art should also know that the embodiments described in the specification are all preferred embodiments, and the actions involved are not necessarily required by the embodiments of the present invention.

[0041] It can be known from the description of the above implementation modes that those skilled in the art can clearly understand that the present application can be implemented by means of software plus a necessary general hardware platform. Based on such an understanding, the technical solution of the present application can be essentially or partly contributed to the prior art in the form of a software product, which can be stored in a storage medium such as ROM / RAM, a magnetic disk, an optical disk, etc., and includes several instructions for enabling a computer device (which can be a personal computer, a server or a network device, etc.) to execute the methods described in the various implementation modes of the present application or certain parts of the implementation modes.

[0042] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A test circuit for measuring the OS and function of an integrated circuit, characterized in that: include: MCU control module, used for executing test programs and data communication; The functional test module includes a Loadboard module and a peripheral circuit switching unit. The Loadboard module is used to carry the IC under test and provide a functional test interface. The peripheral circuit switching unit switches the connection between the pin of the IC under test and the peripheral circuit or the suspended state through a relay group. An OS test module, connected to the functional test module, for performing OS testing; The OS test module is composed of the mirror constant current source circuit, relay switching circuit and absolute value voltage conversion circuit in the functional test module; The mirror image constant current source circuit is configured to output positive and negative currents of fixed values; The relay switching circuit is used to apply the positive and negative currents to the designated pins of the IC under test; The absolute value voltage conversion circuit converts the positive and negative voltages generated by the positive and negative currents flowing through the IC under test into positive voltage signals, and collects the signals through the ADC interface of the MCU control module to determine the OS status.

2. The test circuit according to claim 1, characterized in that: The relay group of the functional test module is controlled by a shift chip driving circuit, and the MCU control module is connected to the IC under test through an IIC communication protocol to obtain its internal temperature data.

3. The test circuit according to claim 1, characterized in that: The mirror image constant current source circuit comprises a self-checking function module, which is used for detecting the output state of the constant current source in real time.

4. The test circuit according to claim 1, characterized in that: The relay switching circuit adopts a G6K model relay with a 24V control voltage, and its action time is less than 10 milliseconds and the driving current is less than 10 mA.

5. The test circuit according to claim 1, characterized in that: The absolute value voltage conversion circuit includes a full-wave rectifier circuit or an absolute value amplifier, which is used to convert positive and negative voltage signals into positive voltage signals.

6. The test circuit according to claim 1, characterized in that: The MCU control module includes: IIC communication interface, used to communicate with the IC under test and the temperature measurement chip on the Loadboard; The shift chip communication interface is used to drive the relay group to achieve test mode switching.

7. The test circuit according to claim 1, characterized in that: The OS test module and the functional test module are configured independently of each other, and support executing OS test and functional test separately or simultaneously.

8. The test circuit according to claim 1, characterized in that: The test circuit obtains the actual junction temperature of the IC under test through the protocol interface and feeds it back to the Handler system to form a temperature control closed loop.

9. The test circuit according to claim 1, characterized in that: The relay group of the Loadboard module is configured to automatically disconnect the IC pins after the test is completed to prevent voltage breakdown.

10. An IC testing method based on the test circuit according to any one of claims 1 to 9, characterized in that: The following steps are involved: Place the IC under test in the test position of the Loadboard module; Select OS test or functional test mode through MCU control module; If OS test is selected, positive and negative currents are output to the pins of the IC under test through a mirror constant current source, and the converted voltage signal is collected to determine the open circuit / short circuit status; If the functional test is selected, the peripheral circuit is provided to the IC under test through relay switching, and its internal temperature data is read through the IIC protocol; After completing the test, disconnect all relay connections and remove the IC under test.

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