Wafer test method, test equipment and storage medium
By setting the initial pin pressure and contact resistance test of the probe card, the problem of low testing efficiency caused by poor contact in wafer testing was solved, and the testing accuracy and efficiency were improved.
Patent Information
- Application Number
- CN202410686964.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-29
- Publication Date
- 2025-12-02
AI Technical Summary
During wafer testing, some dies may fail to make proper contact with the probes but pass the first test, leading to them being judged as unsuccessful in the second test, thus reducing wafer testing efficiency.
By setting the initial probe pressure of the probe card and using point testing and contact resistance testing, good contact between the probe card and the die is ensured, thus improving testing accuracy.
It improves the accuracy and efficiency of wafer testing results, reduces the number of failed chips due to poor contact, and enhances the reliability of the testing process.
Smart Images
Figure CN121049686A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of semiconductor technology, and in particular to a wafer testing method, testing equipment, and storage medium. Background Technology
[0002] A wafer is a silicon chip used in the fabrication of silicon semiconductor integrated circuits. The wafer testing process for memory products such as flash memory typically includes a high-temperature initial test, baking, and a room-temperature second test. During testing, probes are used to contact the dies on the wafer to test them, and failed dies are retested. During testing, some dies may have poor contact with the probes but still pass the initial test. However, these dies will be identified as failed dies in the second test and will not pass the retest, thus reducing wafer testing efficiency. Summary of the Invention
[0003] In view of this, it is necessary to provide a wafer testing method, testing equipment, and storage medium to solve the problem that a die with poor contact with the probe passes the first test but is deemed invalid in the second test, thus reducing the efficiency of wafer testing.
[0004] A first aspect of this application provides a wafer testing method applied to a testing device. The method includes: setting an initial pin pressure of the probe card of the testing device during wafer testing; performing a contact resistance test on the wafer based on the initial pin pressure using the probe card; if the wafer fails the contact resistance test, performing a retest of the contact resistance on the wafer; if the wafer passes the contact resistance test or passes the retest, performing an electrical function test on the wafer; and if the wafer passes the electrical function test, proceeding to the next stage of testing.
[0005] In one possible implementation, setting the initial pin pressure of the probe card of the test equipment during wafer testing includes: dividing the wafer into multiple preset regions, each preset region of the wafer including multiple dies; using the probe card, performing a contact resistance test on the dies in a first preset region based on a first pin pressure; if the dies in the first preset region pass the contact resistance test, using the probe card, performing a contact resistance test on the dies in a second preset region based on the first pin pressure; if the dies in the second preset region pass the contact resistance test, determining the first pin pressure as the initial pin pressure.
[0006] In one possible implementation, setting the initial pin pressure of the probe card of the test equipment during the wafer testing process further includes: if a die in the first preset area or a die in the second preset area fails the contact resistance test, performing a contact resistance test on the die in the second preset area based on the second pin pressure using the probe card; if a die in the second preset area passes the contact resistance test, performing a contact resistance test on the die in the third preset area based on the second pin pressure using the probe card; and if a die in the third preset area passes the contact resistance test, determining the second pin pressure as the initial pin pressure.
[0007] In one possible implementation, the initial pin pressure of the probe card in the wafer testing process of the test equipment further includes: if a die in the second preset region or a die in the third preset region fails the contact resistance test, performing a contact resistance test on the die in the third preset region based on the third pin pressure using the probe card; if a die in the third preset region passes the contact resistance test, performing a contact resistance test on the die in the fourth preset region based on the third pin pressure using the probe card; if a die in the fourth preset region passes the contact resistance test, determining the third pin pressure as the initial pin pressure; if a die in the third preset region or a die in the fourth preset region fails the contact resistance test, pausing the wafer testing.
[0008] In one possible implementation, the step of performing contact resistance testing on the wafer using the probe card based on the initial needle pressure includes: using the probe card to perform contact resistance testing on the dies within a preset area based on the initial needle pressure; if the dies within the preset area fail the contact resistance test, adjusting the initial needle pressure, and performing contact resistance testing on the dies within the preset area based on the adjusted needle pressure; if the number of times the dies within the preset area fail the contact resistance test is greater than or equal to a preset number threshold, marking the preset area as a failure area.
[0009] In one possible implementation, the step of performing contact resistance testing on the wafer using the probe card based on the initial probe pressure further includes: calculating the ratio between the number of chips that failed the contact resistance test in the preset area and the total number of chips to obtain the failure rate of the chips in the preset area; determining whether the failure rate is less than or equal to a preset failure rate threshold; if the failure rate is less than or equal to the preset failure rate threshold, determining that the chips in the preset area have passed the contact resistance test; or if the failure rate is greater than the preset failure rate threshold, determining that the chips in the preset area have failed the contact resistance test.
[0010] In one possible implementation, the contact resistance retest of the wafer includes: retesting the contact resistance of the dies in the failure region of the wafer using the probe card based on the initial probe pressure; if the dies in the failure region pass the contact resistance test, determining that the wafer has passed the contact resistance retest; or if the dies in the failure region fail the contact resistance test, determining that the wafer has failed the contact resistance retest.
[0011] In one possible implementation, the contact resistance test includes a standard contact resistance test and / or an enhanced contact resistance test.
[0012] In one possible implementation, the standard contact resistance test includes: contacting a die on the wafer with the probe card; determining whether the test equipment establishes an electrical connection with the die; if the test equipment establishes an electrical connection with the die, determining that the die passes the standard contact resistance test; or if the test equipment does not establish an electrical connection with the die, determining that the die fails the standard contact resistance test.
[0013] In one possible implementation, the enhanced contact resistance test includes: contacting a die on the wafer with the probe card to determine whether the test equipment establishes an electrical connection with the die; if the test equipment establishes an electrical connection with the die, measuring the contact resistance between the test equipment and the die; determining whether the contact resistance between the test equipment and the die is less than or equal to a preset resistance threshold; if the contact resistance between the test equipment and the die is less than or equal to the preset resistance threshold, determining that the die passes the enhanced contact resistance test; or if the test equipment does not establish an electrical connection with the die, or the contact resistance between the test equipment and the die is greater than the preset resistance threshold, determining that the die fails the enhanced contact resistance test.
[0014] In one possible implementation, the next stage of testing on the wafer includes: baking the wafer, and then performing contact resistance testing and electrical function testing on the baked wafer.
[0015] In one possible implementation, the method further includes: if the wafer fails the contact resistance retest or the wafer fails the electrical function test, suspending the test and outputting a prompt message.
[0016] A second aspect of this application provides a testing device, the testing device including a processor and a memory, the memory being used to store instructions, and the processor being used to call the instructions in the memory, causing the testing device to execute the wafer testing method described above.
[0017] A third aspect of this application provides a computer-readable storage medium comprising computer instructions that, when executed on a test device, cause the test device to perform the wafer testing method described above.
[0018] The wafer testing method, testing equipment, and storage medium provided in this application embodiment ensure good contact between the probe card and the die during the first wafer test by setting the initial probe pressure of the probe card, thereby improving the accuracy of the wafer test results and thus improving the wafer testing efficiency. Attached Figure Description
[0019] Figure 1 This is a schematic diagram of the application environment architecture of a wafer testing method provided in an embodiment of this application.
[0020] Figure 2 This is a flowchart of a wafer testing method provided in one embodiment of this application.
[0021] Figure 3 This is a flowchart of a point measurement method provided in an embodiment of this application.
[0022] Figure 4 This is a flowchart of a contact resistance test provided in an embodiment of this application.
[0023] Figure 5 This is a flowchart of a contact resistance test provided in another embodiment of this application.
[0024] Figure 6 This is a schematic diagram of the structure of a test device provided in one embodiment of this application. Detailed Implementation
[0025] It should be noted that in this application, "at least one" means one or more, and "more than one" means two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone, where A and B can be singular or plural. The terms "first," "second," "third," "fourth," etc. (if present) in the specification, claims, and drawings of this application are used to distinguish similar objects, not to describe a specific order or sequence.
[0026] In the embodiments of this application, the terms "exemplary" or "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described as "exemplary" or "for example" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or design solutions. Specifically, the use of terms such as "exemplary" or "for example" is intended to present the relevant concepts in a specific manner. Unless otherwise specified, the following embodiments and features described herein can be combined with each other.
[0027] A wafer is a silicon chip used in the fabrication of silicon semiconductor integrated circuits. The wafer testing process for memory products such as flash memory typically includes a high-temperature initial test, baking, and a room-temperature second test. During testing, probes contact the dies on the wafer to perform tests, and failed dies are retested. During testing, some dies may have poor contact with the probes but still pass the initial test. However, these dies will be identified as failed dies in the second test and will not pass the retest, thus reducing wafer testing efficiency. Furthermore, the initial probe pressure used by the probe card is usually set manually, and this manually set initial pressure is often inaccurate and tends to be too low, leading to poor contact between the probe and the die and affecting the accuracy of the wafer test results.
[0028] To address the issue of dies failing the initial test due to poor probe contact, thus reducing wafer testing efficiency, this application provides a wafer testing method. This method employs point testing and contact resistance testing to set the initial probe pressure of the probe card, ensuring good contact between the probe card and the die during the initial wafer test. This improves the accuracy of the wafer test results and ultimately increases wafer testing efficiency.
[0029] See Figure 1 The diagram shown illustrates the application environment architecture of the wafer testing method provided in a preferred embodiment of this application. The wafer testing method in this application is applied in a testing device 1, which includes a probe card 100 with multiple probes 101. The testing device 1 can be electrically connected to a wafer 2 via the probes 101. The testing device 1 can be an electronic device with a wafer testing program installed, such as a personal computer, server, or personal digital assistant (PDA).
[0030] See Figure 2 The diagram shown is a flowchart of a wafer testing method provided in an embodiment of this application. The wafer testing method is applied to a testing device, and the method includes:
[0031] S101, Set the initial probe pressure of the test equipment's probe card during the wafer testing process.
[0032] In one embodiment of this application, before testing the wafer, the initial probe pressure of the probe card during the wafer testing process is set based on the spot test method and the contact resistance test method. The probe pressure of the probe card is expressed by OD (Over Drive), which is the displacement of the probe in the Z-axis (i.e., the vertical direction) in micrometers.
[0033] See Figure 3 The diagram shown is a flowchart of a point measurement method provided in an embodiment of this application.
[0034] S1011 divides the wafer into multiple preset regions.
[0035] In one embodiment of this application, each predetermined region of the wafer includes a plurality of grains.
[0036] S1012, using a probe card, performs contact resistance testing on the grains within the first preset area based on the first needle pressure.
[0037] In one embodiment of this application, the probes on the control probe card are aligned with the chips in the first preset area, and the needle pressure of each probe is set to zero. Then, the control probe card is used to contact the chips in the first preset area with the first needle pressure to perform a contact resistance test on the chips in the first preset area.
[0038] In one embodiment of this application, the contact resistance test includes a standard contact resistance test and / or an enhanced contact resistance test. The standard contact resistance test includes: contacting a die on the wafer via a probe card; determining whether the testing equipment establishes an electrical connection with the die; if the testing equipment establishes an electrical connection with the die, the die passes the standard contact resistance test; or if the testing equipment does not establish an electrical connection with the die, the die fails the standard contact resistance test. The enhanced contact resistance test includes: contacting a die on the wafer via a probe card; determining whether the testing equipment establishes an electrical connection with the die; if the testing equipment establishes an electrical connection with the die, measuring the contact resistance between the testing equipment and the die; determining whether the contact resistance between the testing equipment and the die is less than or equal to a preset resistance threshold; if the contact resistance between the testing equipment and the die is less than or equal to the preset resistance threshold, the die passes the enhanced contact resistance test; or if the testing equipment does not establish an electrical connection with the die, or the contact resistance between the testing equipment and the die is greater than the preset resistance threshold, the die fails the enhanced contact resistance test. Understandably, if contact resistance testing includes both standard contact resistance testing and enhanced contact resistance testing, then, provided that the die has passed the standard contact resistance test, the enhanced contact resistance test does not require determining whether the test equipment has established an electrical connection with the die.
[0039] S1013, determine whether the die in the first preset area passes the contact resistance test. If the die in the first preset area passes the contact resistance test, proceed to S1014; if the die in the first preset area fails the contact resistance test, proceed to S1017.
[0040] In one embodiment of this application, if a die in the first preset region fails the first contact resistance test, the contact resistance test is continued on the die in the first preset region. If the number of times the die in the first preset region fails the contact resistance test reaches a preset number, it is determined that the die in the first preset region has failed the contact resistance test. If the die in the first preset region passes any contact resistance test within a preset number, it is determined that the die in the first preset region has passed the contact resistance test. For example, the preset number is three.
[0041] S1014, using a probe card, performs contact resistance testing on the grains within the second preset area based on the first needle pressure.
[0042] S1015, determine whether the die in the second preset area passes the contact resistance test. If the die in the second preset area passes the contact resistance test, proceed to S1016; if the die in the second preset area fails the contact resistance test, proceed to S1017.
[0043] In one embodiment of this application, the probe card performs a contact resistance test on the die in the second preset region based on a first needle pressure. In other embodiments of this application, the probe card may also perform a preset number of contact resistance tests on the die in the second preset region based on the first needle pressure.
[0044] S1016, the first needle pressure is determined as the initial needle pressure.
[0045] S1017, using a probe card, performs contact resistance testing on the grains within the second preset area based on the second needle pressure.
[0046] S1018, determine whether the die in the second preset area passes the contact resistance test. If the die in the second preset area passes the contact resistance test, proceed to S1019; if the die in the second preset area fails the contact resistance test, proceed to S1022.
[0047] In one embodiment of this application, if a die in the second preset region fails the first contact resistance test, the probe card continues to perform contact resistance tests on the die in the second preset region based on the second needle pressure. If the number of times the die in the second preset region fails the contact resistance test reaches a preset number, it is determined that the die in the second preset region has failed the contact resistance test. If the die in the second preset region passes any contact resistance test within a preset number, it is determined that the die in the second preset region has passed the contact resistance test.
[0048] S1019, using a probe card, performs contact resistance testing on the grains within a third preset area based on the second needle pressure.
[0049] S1020, determine whether the die in the third preset area passes the contact resistance test. If the die in the third preset area passes the contact resistance test, proceed to S1021; if the die in the third preset area fails the contact resistance test, proceed to S1022.
[0050] In one embodiment of this application, the probe card performs a contact resistance test on the die in the third preset area based on the second needle pressure.
[0051] S1021, the second needle pressure is set as the initial needle pressure.
[0052] S1022, using a probe card, performs contact resistance testing on the grains within a third preset area based on the third needle pressure.
[0053] S1023, determine whether the die in the third preset area passes the contact resistance test. If the die in the third preset area passes the contact resistance test, proceed to S1024; if the die in the third preset area fails the contact resistance test, proceed to S1027.
[0054] In one embodiment of this application, if a die in the third preset region fails the first contact resistance test, the probe card continues to perform contact resistance tests on the die in the third preset region based on the third pin pressure. If the number of times the die in the third preset region fails the contact resistance test reaches a preset number, it is determined that the die in the third preset region has failed the contact resistance test. If the die in the third preset region passes any contact resistance test within a preset number, it is determined that the die in the third preset region has passed the contact resistance test.
[0055] S1024, using a probe card, performs contact resistance testing on the grains within the fourth preset area based on the third needle pressure.
[0056] S1025, determine whether the die in the fourth preset area passes the contact resistance test. If the die in the fourth preset area passes the contact resistance test, proceed to S1026; if the die in the fourth preset area fails the contact resistance test, proceed to S1027.
[0057] In one embodiment of this application, the probe card performs a contact resistance test on the die in the fourth preset area based on the third needle pressure.
[0058] S1026, the third needle pressure is determined as the initial needle pressure.
[0059] S1027, Suspend wafer testing and perform anomaly handling. For example, anomaly handling includes, but is not limited to, analyzing why the wafer failed the contact resistance test.
[0060] S102 performs contact resistance testing on the wafer based on the initial needle pressure using a probe card.
[0061] In one embodiment of this application, the wafer to be tested can be a wafer on a flash memory product, and the wafer testing process can include a first stage of high-temperature testing and baking, and a second stage of room-temperature testing. During the high-temperature testing and room-temperature testing, it is necessary to perform contact resistance testing on the wafer to ensure that the test probes maintain good ohmic contact with the dies on the wafer under test, so as not to affect the subsequent functional testing of the dies.
[0062] See Figure 4 The diagram shown is a flowchart of a contact resistance test provided in an embodiment of this application.
[0063] S201, using a probe card, performs contact resistance testing on the grains within a preset area based on the initial needle pressure.
[0064] In one embodiment of this application, the contact resistance test includes a standard contact resistance test and / or an enhanced contact resistance test.
[0065] S202, determine whether the die in the preset area passes the contact resistance test. If the die in the preset area passes the contact resistance test, proceed to S203; if the die in the preset area fails the contact resistance test, proceed to S204.
[0066] In one embodiment of this application, the ratio between the number of chips that failed the contact resistance test within a preset area and the total number of chips is calculated to obtain the failure rate of the chips within the preset area; it is then determined whether the failure rate is less than or equal to a preset failure rate threshold; if the failure rate is less than or equal to the preset failure rate threshold, it is determined that the chips within the preset area passed the contact resistance test; if the failure rate is greater than the preset failure rate threshold, it is determined that the chips within the preset area failed the contact resistance test. In one embodiment of this application, the preset failure rate threshold can be 85%, 90%, 95%, or other percentage values.
[0067] S203, perform contact resistance testing on the grains in another preset area.
[0068] S204, adjust the probe pressure of the probe card, and perform contact resistance testing on the chips in the preset area based on the adjusted probe pressure.
[0069] In one embodiment of this application, adjusting the needle pressure of the probe card includes increasing the needle pressure of the probe card.
[0070] S205, determine whether the die in the preset area passes the contact resistance test. If the die in the preset area passes the contact resistance test, the process proceeds to S203; if the die in the preset area fails the contact resistance test, the process proceeds to S206.
[0071] S206, if the number of times the grains in the preset area fail the contact resistance test is greater than or equal to the preset number threshold, the preset area is marked as a failure area.
[0072] In one embodiment of this application, the preset number of times threshold is 2, 3, 4 or other values.
[0073] S103, determine whether the wafer passes the contact resistance test. If the wafer passes the contact resistance test, proceed to S106; if the wafer fails the contact resistance test, proceed to S104.
[0074] S104, perform contact resistance retest on the wafer.
[0075] In one embodiment of this application, the contact resistance of the dies in the failure region of the wafer is retested using a probe card based on the initial probe pressure. If the dies in the failure region pass the contact resistance test, the wafer is determined to have passed the contact resistance retest; if the dies in the failure region fail the contact resistance test, the wafer is determined to have failed the contact resistance retest. In one embodiment of this application, the method for retesting the contact resistance of the wafer is the same as the method for the first contact resistance test of the wafer, and will not be described in detail here.
[0076] S105, determine whether the wafer has passed the contact resistance retest. If the wafer passes the contact resistance retest, proceed to S106; if the wafer fails the contact resistance retest, proceed to S109.
[0077] S106 performs electrical functional tests on the wafer.
[0078] In one embodiment of this application, a probe on a probe card contacts a die on a wafer to collect at least one electrical parameter of the die, and determines whether the wafer passes an electrical function test based on the at least one electrical parameter. The at least one electrical parameter includes, but is not limited to, voltage, current, frequency, and response time.
[0079] S107, determine whether the wafer has passed the electrical function test. If the wafer passes the electrical function test, proceed to S108; if the wafer fails the electrical function test, proceed to S109.
[0080] In one embodiment of this application, it is determined whether each electrical parameter is within its corresponding preset parameter range. If each electrical parameter is within its corresponding preset parameter range, the wafer is determined to have passed the electrical function test. If any electrical parameter is outside its corresponding preset parameter range, the wafer is determined to have failed the electrical function test.
[0081] S108, the wafer is then subjected to the next stage of testing.
[0082] In one embodiment of this application, the wafer is baked, and the baked wafer is subjected to contact resistance testing and electrical function testing. The next stage of testing is a room temperature test.
[0083] In another embodiment of this application, the method further includes: determining whether the wafer's die yield is greater than or equal to a preset yield threshold; if the die yield is greater than or equal to the preset yield threshold, proceeding to the next stage of testing on the wafer; if the die yield is less than the preset yield threshold, pausing the test and outputting a prompt message. The die yield is the ratio between the number of dies on the wafer that pass the contact resistance test and the electrical function test, and the total number of dies on the wafer. For example, the preset yield threshold is 90%.
[0084] S109, pause the test and output a prompt message.
[0085] In one embodiment of this application, a prompt message is used to notify the operator of a wafer test failure. The testing equipment also includes a display screen (not shown), and the prompt message may be information displayed on the display screen. In other embodiments of this application, the prompt message may also be a voice message or a short message sent to the operator's terminal device.
[0086] See Figure 5The diagram shown is a flowchart of a contact resistance test provided in another embodiment of this application.
[0087] S301 performs a standard contact resistance test on the dies in a preset area on the wafer based on the initial needle pressure using a probe card.
[0088] S302, determine whether the die in the preset area passes the general contact resistance test. If the die in the preset area passes the general contact resistance test, proceed to S303; if the die in the preset area fails the general contact resistance test, proceed to S306.
[0089] S303 performs enhanced contact resistance testing on the grains within a preset area using a probe card based on initial needle pressure.
[0090] S304, determine whether the die in the preset area passes the enhanced contact resistance test. If the die in the preset area passes the enhanced contact resistance test, proceed to S305; if the die in the preset area fails the ordinary contact resistance test, proceed to S306.
[0091] S305, Perform parameter testing on the grains within the preset area. The parameter testing is the electrical function testing described in the above embodiments.
[0092] S306, adjusts the initial needle pressure of the probe card, and performs a general contact resistance test on the chips in the preset area based on the adjusted needle pressure.
[0093] S307, determine whether the die in the preset area passes the general contact resistance test. If the die in the preset area passes the general contact resistance test, proceed to S308; if the die in the preset area fails the general contact resistance test, proceed to S311.
[0094] S308 performs enhanced contact resistance testing on the grains within a preset area using a probe card based on adjusted needle pressure.
[0095] S309, determine whether the die in the preset area passes the enhanced contact resistance test. If the die in the preset area passes the enhanced contact resistance test, proceed to S310; if the die in the preset area fails the ordinary contact resistance test, proceed to S311.
[0096] S310 performs parameter testing on the grains within a preset area.
[0097] S311, the probe card's needle pressure is adjusted again, and the probe card performs a standard contact resistance test on the chips in the preset area based on the readjusted needle pressure.
[0098] S312, determine whether the die in the preset area passes the ordinary contact resistance test. If the die in the preset area passes the ordinary contact resistance test, proceed to S313; if the die in the preset area fails the ordinary contact resistance test, proceed to S316.
[0099] S313 performs enhanced contact resistance testing on the grains within a preset area using a probe card based on the readjusted needle pressure.
[0100] S314, determine whether the die in the preset area passes the enhanced contact resistance test. If the die in the preset area passes the enhanced contact resistance test, proceed to S315; if the die in the preset area fails the ordinary contact resistance test, proceed to S316.
[0101] S315, parameter testing of grains within a preset area.
[0102] S316, mark the preset area as a failed area.
[0103] Please see Figure 6 The diagram shown is a structural schematic of a testing device provided in an embodiment of this application.
[0104] The test equipment 1 includes, but is not limited to, a processor 11, a memory 12, and a computer program stored in the memory 12 and executable on the processor 11. For example, the computer program is a wafer testing program. When the processor 11 executes the computer program, it implements the steps in the wafer testing method.
[0105] For example, the computer program may be divided into one or more modules / units, which are stored in the memory 12 and executed by the processor 11 to complete this application. The one or more modules / units may be a series of computer program instruction segments capable of performing specific functions, the instruction segments describing the execution process of the computer program in the test device 1.
[0106] Those skilled in the art will understand that the schematic diagram is merely an example of test device 1 and does not constitute a limitation on test device 1. It may include more or fewer components than shown in the diagram, or combine certain components, or different components. For example, test device 1 may also include input / output devices, network access devices, buses, etc.
[0107] The processor 11 can be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor can be a microprocessor, or the processor 11 can be any conventional processor. The processor 11 is the control center of the test equipment 1, connecting all parts of the test equipment 1 via various interfaces and lines.
[0108] The memory 12 can be used to store the computer programs and / or modules / units. The processor 11 implements various functions of the test device 1 by running or executing the computer programs and / or modules / units stored in the memory 12 and calling the data stored in the memory 12. The memory 12 may mainly include a program storage area and a data storage area. The program storage area may store the operating system, application programs required for at least one function (such as sound playback function, image playback function, etc.), etc.; the data storage area may store data created according to the use of the test device 1, etc. In addition, the memory 12 may include volatile and non-volatile memory, such as hard disk, memory, plug-in hard disk, smart media card (SMC), secure digital (SD) card, flash card, at least one disk storage device, flash memory device, or other storage devices.
[0109] If the modules / units integrated in the test equipment 1 are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, all or part of the processes in the methods of the above embodiments can also be implemented by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium, and when executed by a processor, it can implement the steps of the various method embodiments described above. The computer program includes computer program code, which can be in the form of source code, object code, executable files, or certain intermediate forms. The computer-readable medium can include: any entity or device capable of carrying the computer program code, a recording medium, a USB flash drive, a portable hard drive, a magnetic disk, an optical disk, a computer memory, a read-only memory (ROM), or a random access memory (RAM).
[0110] The extended content of the specific embodiments of the computer-readable storage medium described in this application is basically the same as the embodiments of the wafer testing method described above, and will not be repeated here.
[0111] The wafer testing method, testing equipment, and storage medium provided in this application embodiment ensure good contact between the probe card and the die during the first wafer test by setting the initial probe pressure of the probe card, thereby improving the accuracy of the wafer test results and thus improving the wafer testing efficiency.
[0112] It will be apparent to those skilled in the art that this application is not limited to the details of the exemplary embodiments described above, and that this application can be implemented in other specific forms without departing from the spirit or essential characteristics of this application. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of this application is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be embraced within this application. No reference numerals in the claims should be construed as limiting the scope of the claims. Furthermore, it is clear that the word "comprising" does not exclude other units or steps, and the singular does not exclude the plural. Multiple units or devices recited in the apparatus claims may also be implemented by the same unit or device in software or hardware. The terms "first," "second," etc., are used to indicate names and do not indicate any particular order.
[0113] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application and are not intended to limit it. Although this application has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of this application without departing from the spirit and scope of the technical solutions of this application.
Claims
1. A wafer testing method, applied to testing equipment, characterized in that, The method includes: Set the initial probe pressure of the probe card of the test equipment during the wafer testing process; The contact resistance of the wafer is tested using the probe card based on the initial needle pressure. If the wafer fails the contact resistance test, the contact resistance of the wafer shall be retested; If the wafer passes the contact resistance test or passes the contact resistance retest, the wafer undergoes an electrical function test. If the wafer passes the electrical function test, the wafer will proceed to the next stage of testing.
2. The wafer testing method as described in claim 1, characterized in that, The initial probe pressure setting of the probe card of the test equipment during the wafer testing process includes: The wafer is divided into multiple preset regions, and each preset region of the wafer includes multiple grains; The contact resistance of the grains in the first preset area is tested using the probe card based on the first needle pressure. If the die in the first preset area passes the contact resistance test, the die in the second preset area is tested for contact resistance using the probe card based on the first needle pressure. If the grains in the second preset area pass the contact resistance test, the first needle pressure is determined as the initial needle pressure.
3. The wafer testing method as described in claim 2, characterized in that, The initial probe pressure setting of the probe card of the test equipment during the wafer testing process also includes: If the die in the first preset area or the die in the second preset area fails the contact resistance test, the contact resistance test is performed on the die in the second preset area using the probe card based on the second needle pressure. If the die in the second preset area passes the contact resistance test, the die in the third preset area is tested for contact resistance using the probe card based on the second needle pressure. If the grains in the third preset region pass the contact resistance test, the second needle pressure is determined as the initial needle pressure.
4. The wafer testing method as described in claim 3, characterized in that, The initial probe pressure setting of the probe card of the test equipment during the wafer testing process also includes: If the die in the second preset area or the die in the third preset area fails the contact resistance test, the contact resistance test is performed on the die in the third preset area using the probe card based on the third needle pressure. If the die in the third preset area passes the contact resistance test, the die in the fourth preset area is tested for contact resistance using the probe card based on the third needle pressure. If the grains in the fourth preset area pass the contact resistance test, the third needle pressure is determined as the initial needle pressure; If a die in the third preset region or a die in the fourth preset region fails the contact resistance test, the wafer test is suspended.
5. The wafer testing method as described in claim 2, characterized in that, The step of performing contact resistance testing on the wafer using the probe card based on the initial needle pressure includes: Using the probe card, based on the initial needle pressure, the contact resistance of the grains within a preset area is tested; If the die in the preset area fails the contact resistance test, the initial needle pressure is adjusted, and the contact resistance test is performed on the die in the preset area based on the adjusted needle pressure. If the number of times a grain in the preset area fails the contact resistance test is greater than or equal to a preset threshold number, the preset area is marked as a failure area.
6. The wafer testing method as described in claim 5, characterized in that, The step of performing contact resistance testing on the wafer based on the initial needle pressure using the probe card also includes: Calculate the ratio between the number of grains that failed the contact resistance test in the preset area and the total number of grains to obtain the failure rate of the grains in the preset area; Determine whether the failure rate is less than or equal to a preset failure rate threshold; If the failure rate is less than or equal to the preset failure rate threshold, determine if the grain-through contact resistance test is performed within the preset region; or If the failure rate is greater than the preset failure rate threshold, it is determined that the grains in the preset region have failed the contact resistance test.
7. The wafer testing method as described in claim 5, characterized in that, The retesting of the contact resistance of the wafer includes: The contact resistance of the dies in the failure region of the wafer is retested using the probe card based on the initial needle pressure. If the grains in the failure region pass the contact resistance test, it is determined that the wafer has passed the contact resistance retest; or If the grains in the failure area fail the contact resistance test, the wafer is determined to have failed the contact resistance retest.
8. The wafer testing method according to any one of claims 1 to 7, characterized in that, The contact resistance test includes ordinary contact resistance test and / or enhanced contact resistance test.
9. The wafer testing method as described in claim 8, characterized in that, The standard contact resistance test includes: The probe card contacts the grains on the wafer; Determine whether the test equipment has established an electrical connection with the die; If the test equipment establishes an electrical connection with the die, it is determined that the die passes the standard contact resistance test; or If the test equipment fails to establish an electrical connection with the die, the die is determined to have failed the standard contact resistance test.
10. The wafer testing method as described in claim 8, characterized in that, The enhanced contact resistance test includes: By contacting the die on the wafer with the probe card, it is determined whether the test equipment has established an electrical connection with the die. If the test equipment establishes an electrical connection with the die, measure the contact resistance between the test equipment and the die; Determine whether the contact resistance between the test device and the die is less than or equal to a preset resistance threshold. If the contact resistance between the test equipment and the die is less than or equal to the preset resistance threshold, the die is determined to have passed the enhanced contact resistance test; or If the test equipment fails to establish an electrical connection with the die, or if the contact resistance between the test equipment and the die is greater than the preset resistance threshold, the die is determined to have failed the enhanced contact resistance test.
11. The wafer testing method as described in claim 1, characterized in that, The next stage of testing on the wafer includes: The wafer is baked, and the baked wafer is subjected to contact resistance testing and electrical function testing.
12. The wafer testing method as described in claim 1, characterized in that, The method further includes: If the wafer fails the contact resistance retest or the electrical function test, the test will be paused and a prompt message will be output.
13. A testing device, characterized in that, The testing device includes a processor and a memory, the memory being used to store instructions, and the processor being used to invoke the instructions in the memory, causing the testing device to execute the wafer testing method according to any one of claims 1 to 12.
14. A computer-readable storage medium, characterized in that, Includes computer instructions that, when executed on a test device, cause the test device to perform the wafer testing method as described in any one of claims 1 to 12.