Probe testing device

Abstract

The utility model provides probe testing equipment. A specific circuit is designed between the positive electrode of a power supply and a grid voltage supply outlet; the source current input end is connected with the first shunt resistor and then connected with the power MOSFET, and the output end of the power MOSFET serves as the source current output end; the current detection amplifier and the comparator are sequentially connected between the first shunt resistor and the grid electrode of the power MOSFET based on the voltage reference of the positive electrode of the power supply, and the output end of the comparator is connected to the grid electrode of the power MOSFET. A diode and a fifth adjusting resistor for obtaining the required grid voltage by adjusting the resistance value are arranged in the voltage-stabilizing adjusting circuit; a source electrode wire of the probe card is connected to the protection device through a source electrode current input end, and a source electrode current output end in the protection device is connected to the probe; and the output voltage of the output end of the comparator can switch on or switch off the power MOSFET, so that the probe of the probe card is prevented from being oxidized due to over-current and high temperature, and the grid voltage required by stable voltage output is kept.

Description

Technical Field

[0001] The present application relates to the field of semiconductor technology, and in particular to a probe testing device. Background Art

[0002] The probe card is a core component of the wafer and chip testing process, providing an electrical connection between the wafer / silicon chip and the test instrument. When testing the wafer of a power device, it is inevitable that the die (chip) with incomplete edges will be tested. Due to its incomplete nature, it is very likely that the source power supply circuit will short-circuit, causing the current passing through the probe card to increase instantly, causing the needle tip of the probe card to heat up, oxidize, or even melt. Figure 1 As shown, the current protection method is to install a fuse on the pin card.

[0003] Furthermore, when testing a power device whose back seal has not yet been opened, the drain terminal (drain) is blocked, so a path must be created using an adjacent die as the drain terminal. In this case, a gate voltage must be applied to the adjacent die to turn the device on. The current solution is to create a pin card that requires an external battery for power supply. However, dry cell batteries have a limited voltage range and cannot guarantee stable power supply.

[0004] Therefore, a new solution for probe testing is needed. Utility Model Content

[0005] In view of this, an embodiment of this specification provides a probe testing device.

[0006] The embodiments of this specification provide the following technical solutions:

[0007] The embodiment of this specification provides a probe testing device, including: a probe card, a probe and a protection device;

[0008] The protection device includes an input power supply, a power MOSFET, a voltage comparison function circuit, a voltage regulation circuit, a source current output terminal and a gate voltage supply outlet;

[0009] The voltage comparison function circuit and the voltage stabilization adjustment circuit are sequentially connected in series from the positive electrode of the power supply to the gate voltage supply outlet;

[0010] The voltage comparison function circuit includes: a source current input terminal, a first shunt resistor, a current detection amplifier, a second resistor, a comparator, a third resistor and a fourth adjustment resistor;

[0011] The source current input terminal is connected to the first shunt resistor and then to the power MOSFET, and the output terminal of the power MOSFET serves as the source current output terminal;

[0012] The same-direction input terminal and the reverse input terminal of the current detection amplifier are respectively connected to the two ends of the first shunt resistor; the output terminal of the current detection amplifier is connected to the reverse input terminal of the comparator;

[0013] One end of the second resistor is connected to the positive electrode of the power supply, and the other end of the second resistor is connected to the output end of the current detection amplifier;

[0014] One end of the third resistor is connected to the positive electrode of the power supply, and the other end of the third resistor is connected to the inverting input terminal of the comparator;

[0015] One end of the fourth adjustment resistor is connected to the positive electrode of the power supply, and the other end of the fourth adjustment resistor is connected to the output end of the comparator;

[0016] The output of the comparator is connected to the gate of the power MOSFET;

[0017] The voltage stabilization adjustment circuit includes a diode and a fifth adjustment resistor; the diode is used to prevent current reverse flow; the fifth adjustment resistor is used to obtain the required gate voltage by changing its resistance value;

[0018] The source wire of the needle card is connected to the protection device through the source current input terminal of the protection device, and the source current output terminal of the protection device is connected to the probe;

[0019] The output voltage of the comparator output terminal is used to turn on or off the power MOSFET; the required gate voltage maintains a stable voltage output.

[0020] Compared with the prior art, the at least one technical solution adopted in the embodiments of this specification can achieve the following beneficial effects:

[0021] The embodiments of this specification utilize a logic circuit to construct a protection device. Compared to existing fuse-based solutions, this device protects the pins of the pin card from oxidation caused by excessive current and high temperatures, enabling rapid and safe overcurrent protection. Furthermore, the protection device integrates a stable and adjustable power supply comparable to dry cell batteries to accommodate various unpowered devices, providing a stable and product-adjustable gate voltage. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0023] Figure 1 It is a structural diagram of needle card protection in the prior art;

[0024] Figure 2 This is a schematic structural diagram of a needle card protection device according to an embodiment of the present application;

[0025] Figure 3 This is a schematic diagram of the internal circuit of the protection device in the embodiment of the present application;

[0026] Figure 4 This is a schematic diagram of the external perspective view of the protective device in the embodiment of the present application;

[0027] Figure 5 Schematic diagram of some components of the protection device in the embodiment of the present application;

[0028] Figure 6 It is a schematic diagram of another component surface of the protection device in the embodiment of the present application. DETAILED DESCRIPTION

[0029] The embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0030] The following describes the embodiments of the present application through specific examples, and those skilled in the art can easily understand other advantages and effects of the present application from the contents disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The present application can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present application. It should be noted that, in the absence of conflict, the features in the following embodiments and embodiments can be combined with each other. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without making creative work are within the scope of protection of this application.

[0031] It should be noted that various aspects of the embodiments within the scope of the appended claims are described below. It should be apparent that the aspects described herein can be embodied in a wide variety of forms, and any specific structure and / or function described herein is merely illustrative. Based on this application, it should be understood by those skilled in the art that an aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number and aspect described herein can be used to implement an apparatus and / or practice a method. In addition, other structures and / or functionalities other than one or more of the aspects described herein can be used to implement this apparatus and / or practice this method.

[0032] It should also be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present application. The illustrations only show components related to the present application and are not drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component can be changed at will, and the component layout type may also be more complicated.

[0033] Additionally, in the following description, specific details are provided to provide a thorough understanding of the examples, however, one skilled in the art will appreciate that the examples can be practiced without these specific details.

[0034] When testing power device wafers, it's inevitable that incomplete die edges will be detected. This incompleteness can cause a short circuit in the source power supply circuit, causing a sudden increase in current through the pin card, leading to heating, oxidation, or even melting of the pin card's tips. Current protection measures include installing fuses in the pin cards.

[0035] Furthermore, when testing a power device whose back seal has not yet been opened, the Drain-to-N terminal is blocked, requiring the use of an adjacent die to create a path. A gate voltage must be applied to the adjacent die to turn the device on. The current solution involves creating a pin card that requires an external battery for power supply. However, dry cell batteries have a limited voltage range and cannot guarantee stable power supply.

[0036] Based on this, the embodiments of this specification propose a new solution for probe testing equipment. This solution incorporates a logic circuit and a protective circuit. Instead of the existing technology directly connecting the wires to the probe card source, the wires first pass through a protective device before entering the probe card. This prevents short circuits in the power supply circuit, which could cause the probe card's tip to heat up, oxidize, or even melt, thereby achieving rapid and safe overcurrent protection for the probe card. Furthermore, a stable and adjustable power supply comparable to dry cell batteries is implemented to accommodate different products with unopened back seals.

[0037] The following describes the technical solutions provided by various embodiments of the present application in conjunction with the accompanying drawings.

[0038] like Figure 2 and Figure 3 As shown, the embodiment of this specification provides a new probe testing device, including a probe card, a probe and a protection device.

[0039] like Figure 3 As shown, the protection device includes an input power supply, a power MOSFET, a voltage comparison function circuit, a voltage regulation circuit, a source current output terminal and a gate voltage supply outlet;

[0040] The voltage comparison function circuit and the voltage stabilization adjustment circuit are sequentially connected in series from the positive electrode of the power supply to the gate voltage supply outlet;

[0041] The voltage comparison function circuit includes: a source current input terminal, a first shunt resistor, a current detection amplifier, a second resistor, a comparator, a third resistor and a fourth adjustment resistor;

[0042] The source current input terminal is connected to the first shunt resistor and then to the power MOSFET, and the output terminal of the power MOSFET serves as the source current output terminal;

[0043] The current detection amplifier and the comparator are respectively connected between the first shunt resistor and the gate of the power MOSFET based on the voltage reference of the positive electrode of the power supply;

[0044] The same-direction input terminal and the reverse input terminal of the current detection amplifier are respectively connected to the two ends of the first shunt resistor; the output terminal of the current detection amplifier is connected to the reverse input terminal of the comparator;

[0045] One end of the second resistor is connected to the positive electrode of the power supply, and the other end of the second resistor is connected to the output end of the current detection amplifier;

[0046] One end of the third resistor is connected to the positive electrode of the power supply, and the other end of the third resistor is connected to the inverting input terminal of the comparator;

[0047] One end of the fourth adjustment resistor is connected to the positive electrode of the power supply, and the other end of the fourth adjustment resistor is connected to the output end of the comparator;

[0048] The output of the comparator is connected to the gate of the power MOSFET;

[0049] The voltage stabilization adjustment circuit includes a diode and a fifth adjustment resistor; the diode is used to prevent current reverse flow; the fifth adjustment resistor is used to obtain the required gate voltage by changing its resistance value;

[0050] The source wire of the needle card is connected to the protection device through the source current input terminal of the protection device, and the source current output terminal of the protection device is connected to the probe;

[0051] The output voltage of the comparator output terminal is used to turn on or off the power MOSFET; the required gate voltage maintains a stable voltage output.

[0052] Specific implementation principle: The voltage comparison function comparator controls the on / off state of the power MOSFET by comparing the voltage at the output of the current sense amplifier with a reference voltage. When the current is too high, the source circuit automatically disconnects and closes again when the current returns to normal, providing overcurrent protection against probe tips during wafer testing.

[0053] The voltage regulation circuit provides a stable gate voltage during testing, even in the rare case where the back seal remains unremoved, reducing output gate voltage instability caused by battery degradation. Furthermore, by adjusting the resistance value of R5, the output gate voltage can be adapted to the needs of different products. This solves the problem of achieving consistent voltage consistency between different products without disassembling the battery, simplifying operation and avoiding potential damage to the pins.

[0054] In some embodiments, the gate voltage supply outlet is connected to an N-channel device.

[0055] In some embodiments, the first shunt resistor is in the mΩ level.

[0056] In some embodiments, the voltage regulating circuit is connected in parallel with a digital voltmeter.

[0057] In some embodiments, the protection device further includes a power switch, which is arranged between the positive pole of the power supply and the voltage comparison function circuit; the power supply is a 220V AC input and a DC output power supply.

[0058] In some embodiments, the current detection amplifier includes a TP181A1-CR chip, the comparator includes an LM393, and the voltage regulation circuit includes an LM317.

[0059] Specifically, the first shunt resistor is R1 , which is a resistor with a very small resistance, usually at the mΩ level, and is only prepared for the voltage comparison function circuit and does not affect the test performance.

[0060] Circuit components description. The input power supply is designed to be a 220V AC input and a DC output. The output voltage primarily provides voltage for the current sense amplifier and comparator, as well as a reference voltage for the comparator.

[0061] Power switch, controls whether the protection device is turned on.

[0062] Digital voltmeter, a voltmeter connected to a digital display, is used to measure and display the voltage output by the voltage regulation circuit.

[0063] The first shunt resistor R1 is a small resistor, usually in the mΩ level, and is only used to prepare for the voltage comparison function circuit and does not affect the test performance.

[0064] Resistors R2, R3, and R4. Four other fixed-value resistors are used. The values of R1, R2, and R3 are designed based on the power supply voltage and the specifications of the current-sensing amplifier and comparator to ensure proper device operation. The middle resistor in the circuit serves to determine the reference voltage. R4 (the fourth adjustment resistor) is primarily used to adjust the sensitivity to voltage changes.

[0065] The variable resistor R5 (ie, the fifth adjustment resistor) is designed to be a knob-type adjustment resistor for easy operation to obtain the desired gate voltage output.

[0066] Diodes prevent reverse current flow.

[0067] A power MOSFET (or field-effect transistor) controls the source circuit's switching. When the voltage comparison circuit determines the current is too high, it disconnects the circuit, preventing current from flowing into the source circuit and preventing excessive current from being blocked. Because the comparator output voltage becomes positive when the short-circuit current suddenly increases, turning off the MOSFET, which normally remains on, a depletion-mode p-channel power MOSFET is used for ease of control. The AOSP21321 can be used.

[0068] Functional description of the block circuits. The voltage comparison circuit primarily outputs a signal to control the power MOSFET's on / off state. This is achieved by using a comparator to compare a reference voltage with the shunt resistor voltage amplified by the current sense amplifier, and then outputting a logic signal to control the MOSFET's on / off state. When the voltage is greater than a set value, a signal is output to disconnect the power MOSFET, disconnecting the source circuit. When the voltage is less than the set value, a signal is output to turn on the power MOSFET, allowing the source circuit to operate normally.

[0069] like Figure 3 The circuit shown has a wide range of components to choose from. The current sense amplifier can be a chip such as the TP181A1-CR. Its fixed voltage gain facilitates setting the comparator's reference voltage. Its offset voltage is ±100μV, making it sensitive enough for shunt resistors in the milliohm range and ampere-level currents.

[0070] The comparator can be LM393, whose maximum output logic voltage can reach 30V, including the turn-on gate voltage of the startup power MOSFET.

[0071] Since the maximum source current used in wafer testing is typically several amperes, if the probe contacts the edge die, causing a short circuit, the current magnitude can vary significantly. Therefore, the reference voltage does not need to be precisely set; it only needs to be set when the current exceeds a certain value. At the same time, it is important to avoid setting it too low, which may cause the source circuit to be disconnected when a possible pulse occurs, leading to a test error.

[0072] like Figure 3 In the circuit shown, the MOSFET remains on during the voltage comparison period. However, since the high current applied during current testing typically lasts for hundreds of μs, the device described above can complete the logic operation and disconnect the circuit in just a few μs, thus providing overcurrent protection.

[0073] The voltage regulator circuit controls the output gate voltage. Adjust the voltage using the knob and observe the output voltage with a digital voltmeter. The box represents the voltage regulator chip; a mature product like the LM317 can be used.

[0074] In combination with the above embodiment corresponding to the internal protection circuit, the housing of the protection device is set to be a metal box.

[0075] like Figure 3 The input power supply, source current input, GND interface, source current output, power switch, digital voltmeter, and gate voltage supply outlet in the example correspond to the parts of the outer shell with the same names.

[0076] In some embodiments, such as Figure 4 As shown, the metal box is square.

[0077] In some embodiments, a gate voltage supply outlet and a display interface of a digital voltmeter are provided on the first component surface of the protection device, corresponding to the switch and adjustment knob of the voltage stabilization adjustment circuit; a source current input hole, a grounding hole and a source current output hole are provided on the second component surface of the protection device; a power switch and an input power line hole are provided on the third component surface of the protection device; a foot pad is provided on the fourth component surface of the protection device; and ventilation holes are respectively provided on the fifth and sixth component surfaces of the protection device.

[0078] In some embodiments, the fourth component surface is set as the bottom surface of the square, the fifth component surface and the sixth component surface are the side surfaces of the square, the first component surface is the top surface of the square, the second component surface is the front surface of the square, and the third component surface is the back surface of the square.

[0079] like Figure 5 As shown, the three interfaces on the front are the interfaces for the source power supply protection circuit and the ground interface. The wires that were originally connected directly to the pin card source are now passed through this protection device before entering the pin card.

[0080] like Figure 5 and Figure 6 As shown, above the protection device is the output interface for supplying gate voltage. The knob on the right is used to switch the gate voltage and adjust the gate voltage. The center screen is the output gate voltage display, which can be used to observe the gate voltage level.

[0081] The back of the device is equipped with a power switch and a power socket. The switch turns the device on, and the socket provides power to the device.

[0082] There are two ventilation holes on the sides of the protector to prevent the device from overheating.

[0083] There are four rubber pads at the bottom of the protective device, which provide anti-slip cushioning and other protection and convenient placement functions.

[0084] The embodiments in this specification utilize a logic circuit to implement a protection circuit, enabling faster and safer overcurrent protection for the pin card compared to current fuse solutions. This protection circuit also incorporates a stable and adjustable power supply comparable to dry cell batteries to accommodate various products with unopened back seals. This circuit is suitable for n-channel devices. It protects the pin card's pins from oxidation caused by excessive current and high temperatures, while providing a stable, product-adjustable gate voltage.

[0085] By automatically disconnecting the source circuit when the current is too large and reclosing it when the current returns to normal, overcurrent protection is achieved for the pin tip during wafer testing. This device can provide a stable power supply for the gate voltage during special testing where the back seal has not yet been removed, reducing voltage instability caused by battery attenuation. Different gate voltages can be adjusted according to different products, solving the problem of consistency between the fixed battery voltage and the product voltage. At the same time, there is no need to disassemble the battery, which simplifies the operation and avoids possible damage to the pin card.

[0086] The same or similar parts between the various embodiments in this specification can be referred to in conjunction with each other. Each embodiment focuses on the differences from other embodiments. In particular, for the product embodiments described later, since they correspond to the methods, the description is relatively simple. For relevant parts, please refer to the partial description of the system embodiment.

[0087] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present application should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A probe testing device, characterized in that: include: Needle cards, probes and protective devices; The protection device includes an input power supply, a power MOSFET, a voltage comparison function circuit, a voltage regulation circuit, a source current output terminal and a gate voltage supply outlet; The voltage comparison function circuit and the voltage stabilization adjustment circuit are sequentially connected in series from the positive electrode of the power supply to the gate voltage supply outlet; The voltage comparison function circuit includes: a source current input terminal, a first shunt resistor, a current detection amplifier, a second resistor, a comparator, a third resistor and a fourth adjustment resistor; The source current input terminal is connected to the first shunt resistor and then to the power MOSFET, and the output terminal of the power MOSFET serves as the source current output terminal; The same-direction input terminal and the reverse input terminal of the current detection amplifier are respectively connected to the two ends of the first shunt resistor; the output terminal of the current detection amplifier is connected to the reverse input terminal of the comparator; One end of the second resistor is connected to the positive electrode of the power supply, and the other end of the second resistor is connected to the output end of the current detection amplifier; One end of the third resistor is connected to the positive electrode of the power supply, and the other end of the third resistor is connected to the inverting input terminal of the comparator; One end of the fourth adjustment resistor is connected to the positive electrode of the power supply, and the other end of the fourth adjustment resistor is connected to the output end of the comparator; The output of the comparator is connected to the gate of the power MOSFET; The voltage stabilization adjustment circuit includes a diode and a fifth adjustment resistor; the diode is used to prevent current reverse flow; the fifth adjustment resistor is used to obtain the required gate voltage by changing its resistance value; The source wire of the needle card is connected to the protection device through the source current input terminal of the protection device, and the source current output terminal of the protection device is connected to the probe; The output voltage of the comparator output terminal is used to turn on or off the power MOSFET; the required gate voltage maintains a stable voltage output.

2. The probe testing device according to claim 1, wherein: The gate voltage supply outlet is connected to the N-channel device.

3. The probe testing device according to claim 1, wherein: The first shunt resistor is in the mΩ level.

4. The probe testing device according to claim 1, wherein: The voltage regulating circuit is connected in parallel with a digital voltmeter.

5. The probe testing device according to claim 1, wherein: The protection device further includes a power switch, which is arranged between the positive electrode of the power supply and the voltage comparison function circuit; The power supply is 220V AC input and DC output.

6. The probe testing device according to claim 1, wherein: The current detection amplifier includes a TP181A1-CR chip, the comparator includes an LM393, and the voltage regulation circuit includes an LM317.

7. The probe testing device according to any one of claims 1 to 6, characterized in that: The protective device housing is configured as a metal box.

8. The probe testing device according to claim 7, characterized in that: The metal box is square.

9. The probe testing device according to claim 7, wherein: The first component surface of the protection device is provided with a grid voltage supply outlet and a display interface of a digital voltmeter, which corresponds to the switch and adjustment knob of the voltage regulation circuit; A source current input hole, a ground hole, and a source current output hole are provided on the second component surface of the protection device; The third component surface of the protection device is provided with a power switch and an input power line hole; A foot pad is provided on the fourth component surface of the protective device; Ventilation holes are respectively provided on the fifth component surface and the sixth component surface of the protective device.

10. The probe testing device according to claim 9, wherein: The fourth component surface is set as the bottom surface of the square, the fifth component surface and the sixth component surface are the side surfaces of the square, the first component surface is the top surface of the square, the second component surface is the front surface of the square, and the third component surface is the back surface of the square.

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