Probe card tip condition detection method, probe card tip condition detection structure, wafer and wafer test method

Abstract

The invention provides a probe card tip condition detection method, a probe card tip condition detection structure, a wafer and a wafer test method, and relates to a probe card tip condition detection method, which comprises the following steps: determining a plurality of probes to be tested of a probe card; a plurality of probe pads are determined, and a metal wire structure is arranged between every two probe pads in sequence so as to be connected to form a test circuit; probes to be tested are inserted into the corresponding probe pads for contact connection; dividing and designing a plurality of test groups based on the positions of the probe pads in the test circuit, and measuring the contact resistance of the to-be-tested probes and the corresponding probe pads; and judging the tip state of the to-be-tested probe based on the contact resistance of the to-be-tested probe and the corresponding probe pad. The probe point condition of the probe card is monitored by using an electrical test means, so that the test cost is reduced, and the test accuracy and the detection efficiency are further improved.

Description

Technical Field

[0001] The present application relates to the field of semiconductor integrated circuit testing, and in particular to a probe card needle tip condition detection method, structure, wafer, and wafer testing method. Background Art

[0002] The probe card is a test interface that connects the chip under test and the tester in wafer testing. It is mainly used for preliminary measurement of the electrical performance of the chip before chip segmentation and packaging. The common needle materials of the probe card are generally composed of metal tungsten and its alloys or copper and its alloys. The probe card needs to be installed on the probe station and cooperate with the movement of the probe station to realize the test of each chip one by one and screen out defective chips.

[0003] During the test process of wafer mass production, each time the probe card is inserted, the needle tip of the probe card will repeatedly come into friction contact with the probe pad on the wafer. The long-term friction process will cause the needle tip to wear and tear. When the needle tip wear accumulates to a certain extent, the contact condition between the needle tip and the probe pad will deteriorate, thus affecting the transmission of electrical signals during the actual test process. However, the equipment required to detect the needle tip condition (needle tip length, needle diameter, flatness) of the probe card is expensive, the detection process is complicated, and the detection cycle is long.

[0004] Therefore, how to accurately monitor and evaluate the condition of the needle tip and repair the probe card in advance before the life of the needle card is reached is very important to the wafer testing process. Summary of the invention

[0005] The present application utilizes electrical testing methods to monitor the needle tip condition of the probe card, which not only reduces the testing cost but also further improves the testing accuracy and detection efficiency.

[0006] To achieve one, part, or all of the above purposes or other purposes, the present invention provides a probe card needle tip condition detection method, structure, wafer, and wafer testing method.

[0007] In a first aspect, the present application provides a method for detecting a probe card tip condition, comprising: determining a plurality of probes to be tested of the probe card; Determine a plurality of probe pads, and sequentially set a metal wire structure between two of the probe pads to connect and form a test circuit; Insert the probes to be tested into corresponding probe pads for contact connection; Designing a plurality of test groups based on the positions of the probe pads in the test circuit, and measuring the contact resistance between the probes to be tested and the corresponding probe pads; The state of the tip of the probe to be tested is determined based on the contact resistance between the probe to be tested and the corresponding probe pad.

[0008] In some of these embodiments, determining a plurality of probe pads and sequentially arranging a wire structure between two of the probe pads to form a test circuit includes: The wire structures sequentially arranged between two of the probe pads are consistent, that is, the resistance values of the wire structures sequentially arranged between two of the probe pads are the same; Wherein, the wire structure includes wires in at least one metal layer; The wires in the metal layer are at least one of straight-wired wires, serpentine-wired wires, and wires with a preset path.

[0009] In some of these embodiments, dividing and designing a plurality of test groups based on the positions of the probe pads in the test circuit and measuring the contact resistance between the probe to be measured and the corresponding probe pad includes: Taking four adjacent probes to be measured as a first test group and measuring the contact resistance between the middle two probes to be measured in the first test group and the corresponding probe pads; by setting at least one first test group, the contact resistance between the probes to be measured except the first and last probes to be measured and the corresponding probe pads, and the resistance of the wire structure are measured; Taking two adjacent probes to be measured as a second test group, and respectively measuring the contact resistance between the first and last probes to be measured and the corresponding probe pads based on the resistance of the wire structure.

[0010] In some of these embodiments, taking four adjacent probes to be measured as a first test group and measuring the contact resistance between the middle two probes to be measured in the first test group and the corresponding probe pads includes: The four probes to be measured in the first test group are sequentially the first probe to be measured, the second probe to be measured, the third probe to be measured, and the fourth probe to be measured, and the four probe pads corresponding to the four probes to be measured for needle insertion are sequentially the first probe pad, the second probe pad, the third probe pad, and the fourth probe pad; Using the second probe to be measured and the third probe to be measured, voltages V3 and V4 are respectively applied to the second probe pad and the third probe pad, and the current value I1 of the second probe pad or the third probe pad is measured; Using the first probe to be measured and the fourth probe to be measured, the voltage values V1 and V2 of the first probe pad and the fourth probe pad are respectively measured; Based on the voltages V3 and V4, the current value I1, and the voltage values V1 and V2, the contact resistance between the second probe to be measured and the second probe pad, the contact resistance between the third probe to be measured and the third probe pad, and the resistance of the wire structure between adjacent probe pads are calculated.

[0011] In some of these embodiments, taking two adjacent probes to be tested as a second test group, based on the resistance of the metal wire structure, the contact resistances between the first and last probes to be tested and the corresponding probe pads are measured respectively, including: The two probes to be tested in the second test group are the fifth probe to be tested and the sixth probe to be tested in sequence, and the two probe pads corresponding to the two probes to be tested for needle insertion are the fifth probe pad and the sixth probe pad in sequence; wherein, the fifth probe to be tested is the first probe to be tested or the last probe to be tested; Using the fifth probe to be tested and the sixth probe to be tested, voltages V5 and V6 are applied to the fifth probe pad and the sixth probe pad respectively, and the current value I2 of the fifth probe pad or the sixth probe pad is measured; Based on the resistance of the metal wire structure, the contact resistance between the sixth probe to be tested and the sixth probe pad, and the voltages V5, V6 and the current value I2, the contact resistances between the first and last probes to be tested and the corresponding probe pads are calculated.

[0012] In some of these embodiments, based on the contact resistance between the probe to be tested and the corresponding probe pad, the tip state of the probe to be tested is judged, including: Obtain a preset tip contact resistance threshold; Judge whether the contact resistance between the probe to be tested and the corresponding probe pad is less than the tip contact resistance threshold. If so, the state of this probe to be tested is good; otherwise, the state of this probe to be tested is bad and an alarm is given.

[0013] In some of these embodiments, the probe to be tested is inserted into different probe pads multiple times for contact connection, so as to measure multiple contact resistance values between the probe to be tested and the corresponding probe pads; Based on the multiple contact resistance values, the contact resistance between the probe to be tested and the probe pad is determined, which is used to judge the tip state of the probe to be tested.

[0014] In a second aspect, the present application provides a probe card tip condition test structure for implementing the probe card tip condition detection method described in the first aspect. The probe card tip condition test structure includes a plurality of metal wire structures, a plurality of probe pads and a plurality of probes to be tested; The metal wire structures are sequentially arranged between two of the probe pads to form a test circuit; The plurality of probes to be tested are respectively inserted into the corresponding probe pads and are in contact connection with the corresponding probe pads.

[0015] In a third aspect, the present application provides a wafer testing method implemented by using the probe card tip condition test structure described in the second aspect. The wafer testing method includes steps: Install a probe card on a probe station and determine a plurality of probes to be tested of the probe card; Control the wafer under test to enter the probe station, and pierce the test probes to the corresponding probe pads of the wafer under test for contact connection; wherein, the scribing grooves of the wafer under test include a plurality of metal wire structures and a plurality of probe pads, and the metal wire structures are sequentially arranged between two of the probe pads to form a test circuit; Based on the positions of the probe pads in the test circuit, design multiple test groups and measure the contact resistance between the test probes and the corresponding probe pads; Based on the contact resistance between the test probes and the corresponding probe pads, judge the tip states of the test probes: If the states of all the test probes are good, adjust the position of the wafer under test, and use the probe card to pierce the test pads of the wafer under test for subsequent wafer testing; If there is a state alarm for a test probe, stop the subsequent wafer testing until the test probes on all the probe cards pass the state test.

[0016] In a fourth aspect, the present application provides a wafer for implementing the wafer testing method described in the third aspect. The wafer includes a test circuit and a performance testing structure; The test circuit includes a plurality of metal wire structures and a plurality of probe pads. The metal wire structures are sequentially arranged between two of the probe pads to form a test circuit; the test circuit is placed in the scribing groove of the wafer for testing the tip conditions of the probe card; The wafer further includes a performance testing structure for electrically testing the device performance on the wafer.

[0017] Compared with the prior art, the beneficial effects of the present invention mainly include: The present application provides a method for detecting the tip conditions of a probe card. By measuring the contact resistance between the test probes and the corresponding probe pads, the monitoring of the tip conditions of the probe card is realized, which not only reduces the test cost, but also further improves the test accuracy and detection efficiency.

[0018] The tip condition testing structure of the probe card in the present application can be used to quickly detect the tip conditions of the probe card. It is simple and effective, and does not require expensive detection equipment. It can be realized by means of electrical testing.

[0019] The wafer testing method in the present application can first perform the tip condition testing of the probe card before the conventional wafer testing of the wafer under test. After the tip state passes the test, the subsequent wafer testing is carried out. No additional equipment and steps are required, which ensures the accuracy of the subsequent wafer testing.

[0020] For the wafer of the present application, a test circuit for testing the tip condition of a probe card and a performance test structure are designed on the same wafer. By designing the test circuit in the dicing channel of the wafer, it does not affect the placement area of the performance test structure on the chip, and the tip condition of the probe card can be directly tested using this wafer before the device performance test, improving the test accuracy and detection efficiency.

[0021] To make the above and other objects, features, and advantages of the present invention more obvious and understandable, the following specifically enumerates preferred embodiments and, in conjunction with the accompanying drawings, provides a detailed description as follows. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] To more clearly illustrate the technical solutions in the specific embodiments of the present invention, the following will briefly introduce the accompanying drawings required for the description of the embodiments. Obviously, the following-described drawings are only some embodiments of the present invention, and for those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0023] Figure 1 It is a schematic flowchart of a method for detecting the tip condition of a probe card provided in Embodiment 1 of the present application.

[0024] Figure 2 It is a schematic diagram of the probe pad layout design provided by the present application.

[0025] Figure 3 It is a schematic diagram of contact resistance measurement provided in Embodiment 1 of the present application.

[0026] Figure 4 It is a schematic diagram of the circuit structure of the first test group provided in Embodiment 1 of the present application.

[0027] Figure 5 It is a schematic diagram of the circuit structure of the second test group provided in Embodiment 1 of the present application.

[0028] Figure 6 It is a graph of contact resistance experimental data provided in Embodiment 1 of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0029] Regarding the foregoing and other technical contents, features, and effects of the present invention, they will be clearly presented in the following detailed description of a preferred embodiment in conjunction with the reference drawings. The directional terms mentioned in the following embodiments, such as: up, down, left, right, front, or back, etc., are only with reference to the directions of the attached drawings. Therefore, the directional terms used are for illustration and not for limiting the present invention.

[0030] In this application, four adjacent probes to be measured are taken as the first test group, and the contact resistance between the middle two probes to be measured in the first test group and the corresponding probe pads is measured by the Kelvin four-terminal method. Two adjacent probes to be measured are taken as the second test group, and the contact resistance between the first and last probes to be measured and the corresponding probe pads is measured by the two-terminal method. In this application, the measured contact resistance between the probes to be measured and the corresponding probe pads is used as an important reference index for whether the tip condition is normal, thereby realizing the monitoring of the tip condition of the probe card, reducing the test cost, and further improving the test accuracy and detection efficiency.

[0031] The following will elaborate on the embodiments of this application in conjunction with the accompanying drawings. However, those of ordinary skill in the art can understand that in the embodiments of this application, many technical details are proposed to help readers better understand this application. However, even without these technical details and various changes and modifications based on the following embodiments, the technical solutions claimed in this application can still be implemented.

[0032] Embodiment 1 As Figure 1 shown, a method for detecting the tip condition of a probe card includes: Step S1: Determine multiple probes to be measured on the probe card; Step S2: Determine multiple probe pads, and sequentially set a metal wire structure between two probe pads to connect and form a test circuit; Step S3: Pierce the probes to be measured into the corresponding probe pads for contact connection respectively; Step S4: Based on the positions of the probe pads in the test circuit, design multiple test groups and measure the contact resistance between the probes to be measured and the corresponding probe pads; Step S5: Based on the contact resistance between the probes to be measured and the corresponding probe pads, judge the tip state of the probes to be measured.

[0033] Specifically, as Figure 2 shown, the metal wire structure is sequentially connected between two probe pads. Multiple probe pads and the metal wire structure sequentially set between two probe pads form a test circuit; the metal wire structures sequentially set between two probe pads are the same, that is, the resistance values of the metal wire structures sequentially set between two probe pads are the same; both ends of any probe pad except the first and last probe pads are connected to the metal wire. The metal wire structure includes metal wires in at least one metal layer; wherein, the metal wires in the metal layer are at least one of straight-walking metal wires, serpentine-walking metal wires, and metal wires with a preset path, and the width of the metal wire should meet the requirements of the chip design rules; the connection methods of the metal wires between different probe pads and the metal layer combination methods are the same.

[0034] It should be noted that the sequence numbers of steps S1 - S5 are only for convenience of explaining this embodiment, and do not involve the limitation of the execution sequence of the steps of this application. For example, in other embodiments, steps S1 and S2 can be executed simultaneously, or step S2 can be executed first and then step S1. This application does not make specific limitations.

[0035] The probe card is installed on the probe table, and probes are provided on the probe card. The wafer is installed on the wafer chuck. The probes on the probe card are used to pierce the wafer to realize the connection between the wafer and the tester, so as to use the tester to perform wafer testing.

[0036] In this embodiment, by measuring the contact resistance value between the tip of the probe on the probe card and the probe pad, it is used as an important reference index for whether the tip condition is normal, and then the monitoring of the tip condition of the probes on the probe card is realized. As Figure 3 shown, Probing Rc represents the contact resistance between the probe to be measured and the corresponding probe pad, and Metal Rs represents the resistance value of the metal wire structure connecting two adjacent probe pads.

[0037] In this embodiment, based on the position of the probe pads in the test circuit, multiple test groups are designed. The contact resistance between the probe to be measured and the corresponding probe pad is measured, including: taking four adjacent probes to be measured as the first test group, and measuring the contact resistance between the middle two probes to be measured in the first test group and the corresponding probe pads by the Kelvin four-terminal method. By setting at least one first test group, the contact resistance between the probes to be measured except the first and last probes to be measured and the corresponding probe pads, as well as the resistance of the metal wire structure, can be measured; then taking two adjacent probes to be measured as the second test group, based on the resistance of the metal wire structure, the contact resistance between the first and last probes to be measured and the corresponding probe pads is measured by the two-terminal method. By setting two second test groups, the contact resistance between the first and last probes to be measured and the corresponding probe pads is measured respectively.

[0038] Specifically, first, as Figure 4 shown, in this embodiment, taking four adjacent probes to be measured as the first test group, and measuring the contact resistance between the middle two probes to be measured in the first test group and the corresponding probe pads, specifically including: Any four adjacent probe pads are used as a first test group. The four probes to be measured in the first test group are the first probe to be measured, the second probe to be measured, the third probe to be measured, and the fourth probe to be measured in sequence. The four probe pads corresponding to the four probes to be measured and pierced are the first probe pad (Pad1), the second probe pad (Pad2), the third probe pad (Pad3), and the fourth probe pad (Pad4) in sequence; Using the second probe to be measured and the third probe to be measured, voltages V3 and V4 are applied to the second probe pad and the third probe pad respectively, that is, a voltage difference Vf1 is applied to the second probe pad and the third probe pad, and the current value I1 of the second probe pad or the third probe pad is measured; Using the first probe under test and the fourth probe under test, measure the voltage values V1 and V2 of the first probe pad and the fourth probe pad respectively; Based on the voltages V3 and V4, the current value I1, and the voltage values V1 and V2, calculate the contact resistance between the second probe under test and the second probe pad, the contact resistance between the third probe under test and the third probe pad, and the resistance of the metal wire structure between adjacent probe pads. The specific calculation methods are as follows: 1) The contact resistance Rc2 between the second probe under test and the second probe pad = (V3 - V1) / I1; Since the first probe pad (Pad1) and the second probe pad (Pad2) are conductive, the voltage on Pad2 can be measured on Pad1, and the large impedance mode is used to measure the resistance. Therefore, it is considered that (V3 - V1) is the voltage drop of Rc2; in addition, it is considered that the current values measured at the second probe pad or the third probe pad are the same. Therefore, the current can be measured at only one place and recorded as the current value I1; 2) The contact resistance Rc3 between the third probe under test and the third probe pad = (V4 - V2) / I1; Since the third probe pad (Pad3) and the fourth probe pad (Pad4) are conductive, the voltage on Pad3 can be measured on Pad4, and the large impedance mode is used to measure the resistance. Therefore, it is considered that (V4 - V2) is the voltage drop of Rc3; in addition, it is considered that the current values measured at the second probe pad or the third probe pad are the same. Therefore, the current can be measured at only one place and recorded as the current value I1. The same applies to the current flowing through the metal wire structure subsequently; 3) The resistance Rs of the metal wire structure between adjacent probe pads (Pad2 and Pad3) = (V1 - V2) / I1; The voltage value V1 is the voltage on the second probe pad (Pad2), and the voltage value V2 is the voltage on the third probe pad (Pad3). The reason is the same as above and will not be elaborated. Therefore, it is considered that (V1 - V2) is the voltage drop of Rc3; in this embodiment, the resistance values of all metal wire structures arranged between two probe pads are the same, all being Rs.

[0039] In this embodiment, by setting at least one first test group, the contact resistance between the remaining probe under test and the corresponding probe pad except for the first and last probe under test, and the resistance of the metal wire structure are measured. Assuming there are 25 probe under test and 25 corresponding probe pads in total, then Rc2 and Rc3 (the first first test group), Rc4 and Rc5 (the second first test group),..., Rc23 and Rc24 (the 12th first test group) can be measured in the same way by analogy; that is, the tip contact resistance Rc at the first and last pads is measured.

[0040] In this embodiment, by reasonably planning and setting at least one first test group, the contact resistance between the probe to be measured (except the head and tail probes) and the corresponding probe pad is measured by the Kelvin four-terminal method, with reasonable, ingenious and effective design.

[0041] Then, as Figure 5 shown, in this embodiment, two adjacent probes to be measured are used as the second test group, and based on the resistance of the metal wire structure, the contact resistances between the head and tail probes to be measured and the corresponding probe pads are measured respectively, including: The two probes to be measured in the second test group are the fifth probe to be measured and the sixth probe to be measured in sequence, and the two probe pads corresponding to the two needles of the two probes to be measured are the fifth probe pad (Pad1 or Pad25) and the sixth probe pad (Pad2 or Pad24) in sequence; among them, the fifth probe to be measured is the head probe to be measured or the tail probe to be measured; Using the fifth probe to be measured and the sixth probe to be measured, voltages V5 and V6 are applied to the fifth probe pad and the sixth probe pad respectively, that is, a voltage difference Vf2 is applied to the fifth probe pad and the sixth probe pad, and the current value I2 of the fifth probe pad or the sixth probe pad is measured; Based on the resistance of the metal wire structure, the contact resistance between the sixth probe to be measured and the sixth probe pad, and the voltages V5, V6 and the current value I2, the contact resistances between the head and tail probes to be measured and the corresponding probe pads are calculated; the following takes the fifth probe to be measured as the head probe to be measured as an example for illustration, and the specific process is as Figure 5 shown, including: The contact resistance Rc1 between the head probe to be measured and the fifth probe pad (Pad1) = (V5 - V6) / I2 - Rs - Rc2; (V5 - V6) is Vf2. Since the resistances in this circuit loop include the contact resistance Rc1 between the head probe to be measured and Pad1, the contact resistance Rc2 calculated through the foregoing process, and the metal wire structure resistance Rs (in this embodiment, the resistances of all metal wire structures arranged between two probe pads are the same, all being Rs); in addition, it is considered that the current values at the fifth probe pad and the sixth probe pad measured are the same, so only one place can be measured and recorded as the current value I2.

[0042] As Figure 5 shown, similarly, the contact resistance Rc25 between the tail probe to be measured and the corresponding probe pad can be measured as Rc25 = (V5 - V6) / I2 - Rs - Rc24.

[0043] In this embodiment, based on the contact resistance between the probe to be measured and the corresponding probe pad, the tip state of the probe to be measured is judged, including: obtaining a preset tip contact resistance threshold; judging whether the contact resistance between the probe to be measured and the corresponding probe pad is less than the tip contact resistance threshold. If so, the state of the probe to be measured is good, otherwise, the state of the probe to be measured is bad and an alarm is given. In the application scenario of this embodiment, as Figure 6As shown, the preset threshold is 10 ohms, for reference Figure 6 The straight line y = 10 representing this threshold (Rc_Spec); compare the value of the contact resistance with the preset threshold. If the value of the contact resistance is less than 10 ohms, the tip state is normal; if it is greater than 10 ohms, the tip state is abnormal and an alarm is given.

[0044] Figure 6 is a data graph of the contact resistance (Rc) between the 25-pin probe to be tested and the corresponding probe pad. The abscissa represents 23 of the probes to be tested, and the ordinate represents the corresponding contact resistance values; as Figure 6 shown, in this embodiment, the Rc of the tips of all probes is less than Rc_Spec (10 ohms), indicating that the state of the probes to be tested is good, that is, the conditions of all the probe cards are normal.

[0045] It should be noted that Figure 6 the contact resistances of different colors in represent different needle-out directions (the arrangement of the tips) of the probes to be tested. Among them, red represents the Rc of the tip with the needle out upwards, and blue represents the Rc of the tip with the needle out downwards. Generally, the needle-out direction also affects the contact resistance. The figure shows that the Rc value of the tip with the needle out upwards is relatively large, which also proves that the test structure and test method of this embodiment are correct, and the detection method information is relatively unified.

[0046] In this embodiment, the probes to be tested are inserted into different probe pads multiple times for contact connection to measure the contact resistance values between multiple probes to be tested and the corresponding probe pads; based on the multiple contact resistance values, the contact resistance between the probes to be tested and the probe pads is determined to judge the tip state of the probes to be tested. A specific example is as Figure 6 shown. Each contact resistance is basically not a point value, but a plotted interval value, that is, it means that each probe to be tested is inserted into different probe pads multiple times for contact connection to measure multiple contact resistance values, Figure 6 and the median of these multiple contact resistance values is also calculated in. By calculating the contact resistance by inserting each probe to be tested into different probe pads multiple times, the data anomalies caused by accidental errors are avoided, and the reliability of monitoring the tip conditions of the probe card is improved.

[0047] Embodiment 2 This embodiment provides a test structure for the tip conditions of a probe card to implement the method for detecting the tip conditions of the probe card in Embodiment 1. The test structure for the tip conditions of the probe card includes: a plurality of metal wire structures, a plurality of probe pads, and a plurality of probes to be tested; the metal wire structures are sequentially arranged between two probe pads to form a test circuit, and the test circuit can be referred to Figure 2 ; a plurality of probes to be tested are respectively inserted into the corresponding probe pads to make contact connections with the corresponding probe pads.

[0048] In this embodiment, a plurality of probe pads are determined, and a wire structure is sequentially arranged between two probe pads to connect and form a test circuit, including: the wire structures sequentially arranged between two probe pads are consistent, that is, the resistance values of the wire structures sequentially arranged between two probe pads are the same; wherein, the wire structure includes wires in at least one metal layer; the wires in the metal layer are at least one of wires with a straight trace, wires with a serpentine trace, and wires with a preset path trace.

[0049] In summary, the method for detecting the tip condition of the probe card and the test structure for the tip condition of the probe card of the present application realize the monitoring of the tip condition of the probe card by means of electrical testing, which not only reduces the test cost, but also improves the test accuracy and detection efficiency.

[0050] Embodiment 3 This embodiment provides a wafer testing method, which is realized by using the test structure for the tip condition of the probe card in Embodiment 2. The wafer testing method includes the steps of: installing a probe card on a probe table and determining a plurality of probe tips to be tested of the probe card; controlling the wafer to be tested to enter the probe table, and respectively inserting the probe tips to be tested into the corresponding probe pads of the wafer to be tested for contact connection; wherein, the scribing groove of the wafer to be tested includes a plurality of wire structures and a plurality of probe pads, and the wire structures are sequentially arranged between two probe pads to form a test circuit; designing a plurality of test groups based on the positions of the probe pads in the test circuit, and measuring the contact resistance between the probe tips to be tested and the corresponding probe pads; based on the contact resistance between the probe tips to be tested and the corresponding probe pads, judging the tip state of the probe tips to be tested: if the states of all the probe tips to be tested are good, adjusting the position of the wafer to be tested, and using the probe card to insert the needles into the test pads of the wafer to be tested for subsequent wafer testing; if there is an alarm situation for the state of the probe tips to be tested, stopping the subsequent wafer testing until all the probe tips to be tested on all the probe cards pass the state test.

[0051] In this embodiment, the wire structures sequentially arranged between two probe pads are consistent, that is, the resistance values of the wire structures sequentially arranged between two probe pads are the same; wherein, the wire structure includes wires in at least one metal layer; the wires in the metal layer are at least one of wires with a straight trace, wires with a serpentine trace, and wires with a preset path trace.

[0052] In this embodiment, designing a plurality of test groups based on the positions of the probe pads in the test circuit and measuring the contact resistance between the probe tips to be tested and the corresponding probe pads includes: 1) Take four adjacent probes to be measured as the first test group, and measure the contact resistance between the middle two probes to be measured in the first test group and the corresponding probe pads by the Kelvin four-terminal method; by setting at least one first test group, measure the contact resistance between the probes to be measured except the first and last probes to be measured and the corresponding probe pads, as well as the resistance of the metal wire structure. Specifically: the four probes to be measured in the first test group are the first probe to be measured, the second probe to be measured, the third probe to be measured, and the fourth probe to be measured in sequence, and the four probe pads corresponding to the four probes to be measured for needle insertion are the first probe pad, the second probe pad, the third probe pad, and the fourth probe pad in sequence; use the second probe to be measured and the third probe to be measured to apply voltages V3 and V4 on the second probe pad and the third probe pad respectively, and measure the current value I1 of the second probe pad or the third probe pad; use the first probe to be measured and the fourth probe to be measured to measure the voltage values V1 and V2 of the first probe pad and the fourth probe pad respectively; based on the voltages V3 and V4, the current value I1, and the voltage values V1 and V2, calculate the contact resistance between the second probe to be measured and the second probe pad, the contact resistance between the third probe to be measured and the third probe pad, and the resistance of the metal wire structure between adjacent probe pads.

[0053] 2) Take two adjacent probes to be measured as the second test group, and measure the contact resistance between the first and last probes to be measured and the corresponding probe pads respectively by the two-terminal method based on the resistance of the metal wire structure. Specifically: the two probes to be measured in the second test group are the fifth probe to be measured and the sixth probe to be measured in sequence, and the two probe pads corresponding to the two probes to be measured for needle insertion are the fifth probe pad and the sixth probe pad in sequence; among them, the fifth probe to be measured is the first or the last probe to be measured; use the fifth probe to be measured and the sixth probe to be measured to apply voltages V5 and V6 on the fifth probe pad and the sixth probe pad respectively, and measure the current value I2 of the fifth probe pad or the sixth probe pad; based on the resistance of the metal wire structure, the contact resistance between the sixth probe to be measured and the sixth probe pad, and the voltages V5 and V6 and the current value I2, calculate the contact resistance between the first and last probes to be measured and the corresponding probe pads.

[0054] In this embodiment, based on the contact resistance between the probe to be measured and the corresponding probe pad, judge the tip state of the probe to be measured, including: obtaining a preset tip contact resistance threshold; judging whether the contact resistance between the probe to be measured and the corresponding probe pad is less than the tip contact resistance threshold, if so, the state of the probe to be measured is good, otherwise, the state of the probe to be measured is bad and an alarm is given.

[0055] In this embodiment, insert the probe to be measured into different probe pads multiple times for contact connection to measure the contact resistance values between multiple probes to be measured and the corresponding probe pads; based on the multiple contact resistance values, determine the contact resistance between the probe to be measured and the probe pad for judging the tip state of the probe to be measured.

[0056] In this embodiment, a wafer is further provided for implementing the wafer testing method in this embodiment. The wafer includes a test circuit and a performance testing structure. The test circuit includes a plurality of metal wire structures and a plurality of probe pads. The metal wire structures are sequentially arranged between two probe pads to form a test circuit. The test circuit is placed in the dicing slot of the wafer for testing the tip condition of the probe card. The wafer further includes a performance testing structure for electrically testing the device performance on the wafer.

[0057] In summary, based on the probe card tip condition testing structure, the present application proposes an optimized wafer testing method, which realizes that before performing the conventional wafer testing on the wafer to be tested, the tip condition of the probe card can be tested first. After the tip state passes the test, the subsequent wafer testing can be carried out without additional equipment and steps, ensuring the accuracy of the subsequent wafer testing. Further, the present application also provides a wafer for the foregoing wafer testing method. By designing the test circuit in the dicing slot of the wafer, it does not affect the placement area of the performance testing structure on the chip, and can directly use this wafer to test the tip condition of the probe card before the device performance testing, improving the test accuracy and detection efficiency.

[0058] Some commonly used English nouns or letters adopted in the present invention for the convenience of clear description are only used for exemplary reference rather than restrictive interpretation or specific usage, and the protection scope of the present invention should not be limited by their possible Chinese translations or specific letters.

[0059] It should also be noted that in this article, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations.

Claims

1. A method for detecting the condition of a probe card tip, characterized in that: include: determining a plurality of probes to be tested of the probe card; Determine a plurality of probe pads, and sequentially set a metal wire structure between two of the probe pads to connect and form a test circuit; Insert the probes to be tested into corresponding probe pads for contact connection; Designing a plurality of test groups based on the positions of the probe pads in the test circuit, and measuring the contact resistance between the probes to be tested and the corresponding probe pads; The state of the tip of the probe to be tested is determined based on the contact resistance between the probe to be tested and the corresponding probe pad.

2. A method for detecting the condition of a probe card tip according to claim 1, characterized in that: The step of determining a plurality of probe pads and sequentially arranging a metal wire structure between two of the probe pads to connect and form a test circuit comprises: The metal wire structure sequentially arranged between the two probe pads is kept consistent, that is, the resistance value of the metal wire structure sequentially arranged between the two probe pads is the same; Wherein, the metal wire structure comprises metal wires in at least one metal layer; The metal wires in the metal layer are at least one of metal wires in a straight line, metal wires in a serpentine line, and metal wires in a preset path.

3. A method for detecting the condition of a probe card tip according to claim 1, characterized in that: The design of multiple test groups based on the position of the probe pads in the test circuit to measure the contact resistance between the probes to be tested and the corresponding probe pads includes: Taking four adjacent probes to be tested as a first test group, measuring the contact resistance between the middle two probes to be tested of the first test group and the corresponding probe pads; by setting at least one first test group, measuring the contact resistance between the remaining probes to be tested and the corresponding probe pads, and the resistance of the metal wire structure, except for the first and last two probes to be tested; Two adjacent probes to be tested are used as a second test group, and based on the resistance of the metal wire structure, the contact resistances between the first and last two probes to be tested and the corresponding probe pads are respectively measured.

4. A method for detecting the condition of a probe card tip according to claim 3, characterized in that: The method of using four adjacent probes to be tested as a first test group and measuring the contact resistance between two middle probes to be tested of the first test group and the corresponding probe pads includes: The four probes to be tested in the first test group are sequentially a first probe to be tested, a second probe to be tested, a third probe to be tested, and a fourth probe to be tested, and the four probe pads corresponding to the four probes to be tested are sequentially a first probe pad, a second probe pad, a third probe pad, and a fourth probe pad; Using the second probe to be tested and the third probe to be tested, respectively apply voltages V3 and V4 to the second probe pad and the third probe pad, and measure the current value I1 of the second probe pad or the third probe pad; Using a first probe to be tested and a fourth probe to be tested, respectively measuring voltage values ​​V1 and V2 of the first probe pad and the fourth probe pad; Based on the voltages V3 and V4, the current value I1, and the voltage values ​​V1 and V2, the contact resistance between the second probe under test and the second probe pad, the contact resistance between the third probe under test and the third probe pad, and the resistance of the metal wire structure between adjacent probe pads are calculated.

5. A method for detecting the condition of a probe card tip according to claim 4, characterized in that: The method uses two adjacent probes to be tested as a second test group and measures the contact resistances of the first and last two probes to be tested and the corresponding probe pads based on the resistance of the metal wire structure, including: The two probes to be tested in the second test group are the fifth probe to be tested and the sixth probe to be tested, respectively, and the two probe pads corresponding to the two probes to be tested are the fifth probe pad and the sixth probe pad, respectively; wherein the fifth probe to be tested is the first probe to be tested or the last probe to be tested; Using the fifth probe to be tested and the sixth probe to be tested, voltages V5 and V6 are applied to the fifth probe pad and the sixth probe pad, respectively, to measure a current value I2 of the fifth probe pad or the sixth probe pad; Based on the resistance of the metal wire structure, the contact resistance between the sixth probe to be tested and the sixth probe pad, as well as the voltages V5 and V6 and the current value I2, the contact resistances between the first and last two probes to be tested and the corresponding probe pads are calculated.

6. A method for detecting the condition of a probe card tip according to claim 5, characterized in that: The method of determining a needle tip state of the probe to be tested based on a contact resistance between the probe to be tested and a corresponding probe pad includes: Obtaining a preset needle tip contact resistance threshold; It is determined whether the contact resistance between the probe to be tested and the corresponding probe pad is less than the needle tip contact resistance threshold. If so, the state of the probe to be tested is good. Otherwise, the state of the probe to be tested is not good and an alarm is issued.

7. The method for detecting the condition of a probe card tip according to claim 1, characterized in that: Inserting the probes to be tested into different probe pads for multiple times to make contact and connect, so as to measure the contact resistance values ​​between the probes to be tested and the corresponding probe pads; Based on the plurality of contact resistance values, the contact resistance between the probe to be tested and the probe pad is determined to judge the needle tip state of the probe to be tested.

8. A probe card needle tip condition testing structure, used to implement the probe card needle tip condition detection method according to any one of claims 1 to 7, characterized in that: The probe card needle tip condition test structure includes a plurality of metal wire structures, a plurality of probe pads and a plurality of probes to be tested; The metal wire structure is sequentially arranged between two of the probe pads to form a test circuit; The plurality of probes to be tested are respectively inserted into corresponding probe pads to be contacted and connected with the corresponding probe pads.

9. A wafer testing method, implemented by using the probe card needle tip condition testing structure according to claim 8, characterized in that: The wafer testing method comprises the steps of: Installing a probe card on a probe station, and determining a plurality of probes to be tested on the probe card; Control the wafer to be tested to enter the probe station, and insert the probes to be tested into the corresponding probe pads of the wafer to be tested for contact connection; wherein the scribe groove of the wafer to be tested includes a plurality of metal wire structures and a plurality of probe pads, and the metal wire structures are sequentially arranged between two of the probe pads to form a test circuit; Designing a plurality of test groups based on the positions of the probe pads in the test circuit, and measuring the contact resistance between the probes to be tested and the corresponding probe pads; Based on the contact resistance between the probe to be tested and the corresponding probe pad, the needle tip state of the probe to be tested is determined: If the states of all the probes to be tested are good, the position of the wafer to be tested is adjusted, and the probe card is used to pierce the test pads of the wafer to be tested for subsequent wafer testing; If there is a status alarm of the probe to be tested, subsequent wafer testing is stopped until the probes to be tested on all probe cards pass the status test.

10. A wafer, used to implement the wafer testing method according to claim 9, characterized in that: The wafer includes a test circuit and a performance test structure; The test circuit includes a plurality of metal line structures and a plurality of probe pads, wherein the metal line structures are sequentially arranged between two of the probe pads to form a test circuit; The test circuit is placed in the scribe line of the wafer and is used to test the condition of the probe card tip; The wafer also includes a performance test structure, which is used to perform electrical testing on the performance of the devices on the wafer.

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