[go: up one dir, main page]

CN120044341B - Probe card needle tip condition detection method, structure, wafer and wafer testing method - Google Patents

Probe card needle tip condition detection method, structure, wafer and wafer testing method

Info

Publication number
CN120044341B
CN120044341B CN202510517717.1A CN202510517717A CN120044341B CN 120044341 B CN120044341 B CN 120044341B CN 202510517717 A CN202510517717 A CN 202510517717A CN 120044341 B CN120044341 B CN 120044341B
Authority
CN
China
Prior art keywords
probe
tested
probes
pads
pad
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN202510517717.1A
Other languages
Chinese (zh)
Other versions
CN120044341A (en
Inventor
陈海平
林均铭
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Hangzhou Guangli Microelectronics Co ltd
Original Assignee
Hangzhou Guangli Microelectronics Co ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Hangzhou Guangli Microelectronics Co ltd filed Critical Hangzhou Guangli Microelectronics Co ltd
Priority to CN202510517717.1A priority Critical patent/CN120044341B/en
Publication of CN120044341A publication Critical patent/CN120044341A/en
Application granted granted Critical
Publication of CN120044341B publication Critical patent/CN120044341B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • GPHYSICS
    • G01MEASURING; TESTING
    • G01RMEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R31/00Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01RMEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R27/00Arrangements for measuring resistance, reactance, impedance, or electric characteristics derived therefrom
    • G01R27/02Measuring real or complex resistance, reactance, impedance, or other two-pole characteristics derived therefrom, e.g. time constant
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01RMEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R31/00Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
    • G01R31/26Testing of individual semiconductor devices
    • G01R31/2601Apparatus or methods therefor
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01LSEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L22/00Testing or measuring during manufacture or treatment; Reliability measurements, i.e. testing of parts without further processing to modify the parts as such; Structural arrangements therefor
    • H01L22/10Measuring as part of the manufacturing process
    • H01L22/14Measuring as part of the manufacturing process for electrical parameters, e.g. resistance, deep-levels, CV, diffusions by electrical means
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01LSEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L22/00Testing or measuring during manufacture or treatment; Reliability measurements, i.e. testing of parts without further processing to modify the parts as such; Structural arrangements therefor
    • H01L22/30Structural arrangements specially adapted for testing or measuring during manufacture or treatment, or specially adapted for reliability measurements
    • H01L22/34Circuits for electrically characterising or monitoring manufacturing processes, e. g. whole test die, wafers filled with test structures, on-board-devices incorporated on each die, process control monitors or pad structures thereof, devices in scribe line

Landscapes

  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Computer Hardware Design (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Power Engineering (AREA)
  • Automation & Control Theory (AREA)
  • Testing Or Measuring Of Semiconductors Or The Like (AREA)
  • Measuring Leads Or Probes (AREA)

Abstract

The application provides a probe card tip condition detection method, a structure, a wafer and a wafer test method, and relates to a probe card tip condition detection method, comprising the steps of determining a plurality of probes to be tested of a probe card; the method comprises the steps of determining a plurality of probe pads, sequentially arranging a metal wire structure between two probe pads to be connected to form a test circuit, respectively inserting probes to be tested into the corresponding probe pads to be in contact connection, dividing and designing a plurality of test groups based on the positions of the probe pads in the test circuit, measuring the contact resistance of the probes to be tested and the corresponding probe pads, and judging the state of the needle tip of the probes to be tested based on the contact resistance of the probes to be tested and the corresponding probe pads. The application monitors the needle point condition of the probe card by utilizing an electrical test means, thereby reducing the test cost and further improving the test accuracy and the detection efficiency.

Description

Method and structure for detecting probe card needle point condition, wafer and wafer testing method
Technical Field
The present application relates to the field of semiconductor integrated circuit testing, and more particularly, to a probe card tip status detection method, structure, wafer, and wafer testing method.
Background
The probe card is a test interface for connecting a tested chip and a tester in wafer test, is mainly used for preliminary measurement of the electrical property of the chip before chip slicing and packaging, is generally made of tungsten metal or alloy thereof or copper or alloy thereof, needs to be mounted on a probe platform, and is matched with the movement of the probe platform to realize the test of the chips one by one and screen out bad chips.
In the test process of wafer mass production, when the probe card is in needle setting every time, the needle point of the probe card can repeatedly make friction contact with the probe pad on the wafer, the long-term friction process can cause abrasion consumption of the needle point, and when the abrasion of the needle point is accumulated to a certain degree, the contact condition of the needle point and the probe pad can be worsened, so that the transmission of electric signals in the actual test process is affected. However, the equipment required for detecting the condition of the probe card tip (tip length, needle diameter, flatness) is expensive, the detection process is complex, and the detection period is long.
Therefore, how to accurately monitor and evaluate the needle tip condition, and repair the probe card in advance before the service life of the probe card is reached, is very important for the testing process of the wafer.
Disclosure of Invention
The application monitors the needle point condition of the probe card by utilizing an electrical test means, thereby reducing the test cost and further improving the test accuracy and the detection efficiency.
In order to achieve one or a part or all of the above or other objects, the present invention provides a probe card tip status detection method, structure, wafer and wafer testing method.
In a first aspect, the present application provides a probe card tip condition detection method, comprising:
Determining a plurality of probes to be tested of the probe card;
Determining a plurality of probe pads, and sequentially arranging a metal wire structure between the two probe pads to be connected to form a test circuit;
The probes to be detected are respectively needled to the corresponding probe pads for contact connection;
Dividing and designing a plurality of test groups based on the positions of the probe pads in a test circuit, and measuring the contact resistance of the probes to be tested and the corresponding probe pads;
And judging the state of the tip of the probe to be detected based on the contact resistance of the probe to be detected and the corresponding probe pad.
In some embodiments, the determining a plurality of probe pads, sequentially disposing a metal line structure between two probe pads to connect to form a test circuit, includes:
The metal wire structures sequentially arranged between the two probe pads are kept consistent, namely the resistance values of the metal wire structures sequentially arranged between the two probe pads are the same;
Wherein the metal line structure comprises a metal line in at least one metal layer;
the metal wire in the metal layer is at least one of a metal wire with a straight line, a metal wire with a snake-shaped line and a metal wire with a preset path line.
In some embodiments, the designing a plurality of test groups based on the position division of the probe pads in the test circuit, measuring the contact resistance between the probe to be tested and the corresponding probe pad includes:
Measuring contact resistance between two probes to be tested in the middle of a first test group and a corresponding probe pad by using four adjacent probes to be tested as the first test group; the contact resistance of the probes to be tested and the corresponding probe pads except the first probe to be tested and the second probe to be tested and the resistance of the metal wire structure are measured by arranging at least one first test group;
And respectively measuring the contact resistance of the first and the last two probes to be tested and the corresponding probe pads based on the resistance of the metal wire structure by taking the two adjacent probes to be tested as a second test group.
In some embodiments, the measuring the contact resistance between the middle two probes to be tested and the corresponding probe pad of the first test set with the adjacent four probes to be tested as the first test set 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 and inserted with needles are sequentially a first probe pad, a second probe pad, a third probe pad and a fourth probe pad;
Applying voltages V3 and V4 on the second probe pad and the third probe pad respectively by using the second probe to be tested and the third probe to be tested, and measuring a current value I1 of the second probe pad or the third probe pad;
measuring voltage values V1 and V2 of the first probe pad and the fourth probe pad respectively by using the first probe to be measured and the fourth probe to be measured;
And calculating to obtain the contact resistance of the second probe to be detected and the second probe pad, the contact resistance of the third probe to be detected and the third probe pad and the resistance of the metal wire structure between the adjacent probe pads based on the voltages V3 and V4, the current value I1 and the voltage values V1 and V2.
In some embodiments, the measuring the contact resistance between the first and the last two probes to be measured and the corresponding probe pads based on the resistance of the metal wire structure with the two adjacent probes to be measured as the second test group includes:
The two probes to be tested in the second test group are sequentially a fifth probe to be tested and a sixth probe to be tested, and the two probe pads corresponding to the two probes to be tested and inserted into the needle are sequentially a fifth probe pad and a sixth probe pad, wherein the fifth probe to be tested is a first probe to be tested or a tail probe to be tested;
applying voltages V5 and V6 to the fifth probe pad and the sixth probe pad respectively by using the fifth probe to be tested and the sixth probe to be tested, and measuring a current value I2 of the fifth probe pad or the sixth probe pad;
And calculating to obtain the contact resistance of the first and the last probes to be tested and the corresponding probe pads based on the resistance of the metal wire structure, the contact resistance of the sixth probes to be tested and the sixth probe pads, the voltages V5 and V6 and the current value I2.
In some embodiments, determining the state of the tip of the probe to be tested based on the contact resistance of the probe to be tested and the corresponding probe pad includes:
acquiring a preset needle tip contact resistance threshold;
Judging whether the contact resistance of the probe to be detected and the corresponding probe pad is smaller than the contact resistance threshold of the needle tip, if yes, the state of the probe to be detected is good, and if not, the state of the probe to be detected is bad and an alarm is given.
In some embodiments, the probes to be tested are needled to different probe pads for contact connection for multiple times, so as to obtain contact resistance values of the probes to be tested and the corresponding probe pads through measurement;
And determining the contact resistance of the probe to be detected and the probe pad based on the contact resistance values, and judging the state of the tip of the probe to be detected.
In a second aspect, the present application provides a probe card tip condition testing structure, for implementing the probe card tip condition detection method of the first aspect, where the probe card tip condition testing 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 the two probe pads to form a test circuit;
And the probes to be detected are respectively needled to the corresponding probe pads and are in contact connection with the corresponding probe pads.
In a third aspect, the present application provides a wafer testing method implemented by using the probe card tip condition testing structure of the second aspect, where the wafer testing method includes the steps of:
mounting a probe card on a probe station, and determining a plurality of probes to be tested of the probe card;
controlling a wafer to be tested to enter a probe table, and respectively needling the probes to be tested to corresponding probe pads of the wafer to be tested for contact connection, wherein a scribing groove of the wafer to be tested comprises a plurality of metal wire structures and a plurality of probe pads, and the metal wire structures are sequentially arranged between the two probe pads to form a test circuit;
Dividing and designing a plurality of test groups based on the positions of the probe pads in a test circuit, and measuring the contact resistance of the probes to be tested and the corresponding probe pads;
Judging the state of the tip of the probe to be detected based on the contact resistance of the probe to be detected and the corresponding probe pad:
if the states of all the probes to be tested are good, the positions of the wafers to be tested are adjusted, and the probe card is used for needling to a test pad of the wafers to be tested so as to carry out subsequent wafer testing;
if the state alarm condition of the probes to be tested exists, the subsequent wafer test is stopped until all the probes to be tested on the probe card pass the state test.
In a fourth aspect, the present application provides a wafer for implementing the wafer testing method according to the third aspect, where the wafer includes a testing circuit and a performance testing structure;
The test circuit comprises a plurality of metal wire structures and a plurality of probe pads, wherein the metal wire structures are sequentially arranged between the two probe pads to form the test circuit;
the wafer also comprises a performance test structure, wherein the performance test structure is used for carrying out electrical test on the performance of devices on the wafer.
Compared with the prior art, the invention has the beneficial effects that:
the application provides a probe card tip condition detection method, which realizes the monitoring of the probe card tip condition by measuring the contact resistance of a probe to be detected and a corresponding probe pad, thereby reducing the test cost and further improving the test accuracy and the detection efficiency.
The probe card tip condition testing structure can be used for rapidly detecting the tip condition of a probe card, is simple and effective, does not need expensive detection equipment, and can be realized by using an electrical testing means.
The wafer testing method can test the needle point state of the probe card before the conventional wafer testing is carried out on the wafer to be tested, and then carry out the subsequent wafer testing after the needle point state passes the testing, so that additional equipment and steps are not required, and the accuracy of the subsequent wafer testing is ensured.
According to the wafer, the test circuit and the performance test structure for testing the probe card tip condition are designed on the same wafer, and the test circuit is designed in the scribing groove of the wafer, so that the placing area of the performance test structure on a chip is not affected, the wafer can be directly used for testing the probe card tip condition before the device performance test, and the test accuracy and the detection efficiency are improved.
The foregoing and other objects, features and advantages of the invention will be apparent from the following more particular description of preferred embodiments, as illustrated in the accompanying drawings.
Drawings
In order to more clearly illustrate the technical solutions of specific embodiments of the present invention, the drawings that are needed in the description of the embodiments will be briefly described below, and it is obvious that the drawings described below are only some embodiments of the present invention, and other drawings may be obtained according to these drawings without inventive effort to a person of ordinary skill in the art.
Fig. 1 is a flow chart of a method for detecting a probe tip condition of a probe card according to embodiment 1 of the present application.
Fig. 2 is a schematic diagram of a probe pad layout provided by the present application.
Fig. 3 is a schematic diagram of contact resistance measurement according to embodiment 1 of the present application.
Fig. 4 is a schematic circuit diagram of a first test set according to embodiment 1 of the present application.
Fig. 5 is a schematic circuit diagram of a second test set according to embodiment 1 of the present application.
Fig. 6 is a graph of experimental contact resistance data provided in example 1 of the present application.
Detailed Description
The foregoing and other features, aspects, and advantages of the present invention will become more apparent from the following detailed description of a preferred embodiment, which proceeds with reference to the accompanying drawings. The directional terms mentioned in the following embodiments, such as up, down, left, right, front or rear, etc., are only referring to the directions of the attached drawings. Thus, the directional terminology is used for purposes of illustration and is not intended to be limiting of the invention.
The application takes four adjacent probes to be tested as a first test group, measures the contact resistance between the middle two probes to be tested and the corresponding probe pad of the first test group by a Kelvin four-terminal method, and takes two adjacent probes to be tested as a second test group, and measures the contact resistance between the first and the last two probes to be tested and the corresponding probe pad by a two-terminal method.
Embodiments of the present application will be described in detail below with reference to the attached drawings. However, it will be understood by those of ordinary skill in the art that in various embodiments of the present application, numerous specific details are set forth in order to provide a thorough understanding of the present application. The claimed application may be practiced without these specific details and with various changes and modifications based on the following embodiments.
Example 1
As shown in fig. 1, a probe card tip condition detection method includes:
step S1, determining a plurality of probes to be tested of a probe card;
step S2, determining a plurality of probe pads, and sequentially arranging a metal wire structure between the two probe pads to be connected to form a test circuit;
step S3, respectively needling the probes to be tested to the corresponding probe pads for contact connection;
S4, 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 probes to be tested and the corresponding probe pads;
and S5, judging the state of the tip of the probe to be detected based on the contact resistance of the probe to be detected and the corresponding probe pad.
Specifically, as shown in fig. 2, the metal wire structure is sequentially connected between two probe pads, the plurality of probe pads and the metal wire structure sequentially arranged between the two probe pads form a test circuit, the metal wire structure sequentially arranged between the two probe pads is kept consistent, namely the resistance value of the metal wire structure sequentially arranged between the two probe pads is the same, and two ends of any probe pad except the head probe pad and the tail probe pad are connected with the metal wire. The metal wire structure comprises at least one metal wire in the metal layer, wherein the metal wire in the metal layer is at least one of a metal wire with a straight line, a metal wire with a snake-shaped line and a metal wire with a preset path line, the width of the metal wire meets the requirement of chip design rules, and the metal wire connecting mode and the metal wire combining mode among different probe pads are the same.
It should be noted that, the order of steps S1-S5 is merely for convenience of description of the present embodiment, and the present application is not limited to the execution order of the steps, for example, in other embodiments, the steps S1 and S2 may be executed simultaneously, or the steps S2 may be executed first and then the steps S1 may be executed, which is not a specific limitation of the present application.
The probe card is arranged on the probe table, the probe card is provided with probes, the wafer is arranged on the wafer chuck, and the connection between the wafer and the testing machine is realized by the needle insertion of the probes on the probe card to the wafer so as to test the wafer by the testing machine.
In the embodiment, the contact resistance value of the probe tip of the probe card and the probe pad is measured to serve as an important reference index for judging whether the probe tip condition is normal or not, so that the monitoring of the probe tip condition on the probe card is realized. As shown in fig. 3, probing Rc represents the contact resistance between the probe to be tested and the corresponding probe pad, and Metal Rs represents the resistance of the Metal line structure connecting two adjacent probe pads.
The embodiment designs a plurality of test groups based on the position division of the probe pads in the test circuit, measures the contact resistance of the probes to be tested and the corresponding probe pads, and comprises the steps of taking four adjacent probes to be tested as first test groups, measuring the contact resistance of the middle two probes to be tested of the first test groups and the corresponding probe pads through a Kelvin four-terminal method, measuring the contact resistance of the rest probes to be tested except the first probes to be tested and the last probes to be tested and the corresponding probe pads through setting at least one first test group, and measuring the contact resistance of the first probes to be tested and the last probes to be tested and the corresponding probe pads through a two-terminal method, and measuring the contact resistance of the first probes to be tested and the last probes to be tested and the corresponding probe pads through setting two second test groups.
Specifically, first, as shown in fig. 4, in this embodiment, four adjacent probes to be tested are used as a first test set, and the contact resistance between two middle probes to be tested and corresponding probe pads of the first test set is measured, which specifically includes:
the four probe pads of the four probes to be tested 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 of the four probes to be tested, which correspond to the needle insertion, are sequentially a first probe Pad (Pad 1), a second probe Pad (Pad 2), a third probe Pad (Pad 3) and a fourth probe Pad (Pad 4);
Applying voltages V3 and V4 to the second probe pad and the third probe pad respectively by utilizing the second probe to be tested and the third probe to be tested, namely applying a voltage difference Vf1 to the second probe pad and the third probe pad, and measuring a current value I1 of the second probe pad or the third probe pad;
Measuring voltage values V1 and V2 of the first probe pad and the fourth probe pad respectively by using the first probe to be measured and the fourth probe to be measured;
Based on the voltages V3 and V4, the current value I1, and the voltage values V1 and V2, a contact resistance between the second probe to be measured and the second probe pad, a contact resistance between the third probe to be measured and the third probe pad, and a resistance of a metal wire structure between adjacent probe pads are calculated, wherein the specific calculation method comprises:
1) Contact resistance Rc2= (V3-V1)/I1 of the second probe pad and the second probe to be tested;
Since the first probe Pad (Pad 1) and the second probe Pad (Pad 2) are conductive, the voltage across Pad2 can be measured across Pad1, and the large impedance mode used by the resistor is measured, thus assuming (V3-V1) to be the voltage drop of Rc 2;
2) Contact resistance Rc3= (V4-V2)/I1 of the third probe pad and the third probe to be tested;
Since the third probe Pad (Pad 3) and the fourth probe Pad (Pad 4) are conductive, the voltage across Pad3 can be measured on Pad4, and the large impedance mode used by the resistor is measured, thus assuming (V4-V2) to be the voltage drop of Rc 3;
3) Resistance rs= (V1-V2)/I1 of the metal line structure between adjacent probe pads (Pad 2 and Pad 3);
The voltage value V1 is the voltage on the second probe Pad (Pad 2), the voltage value V2 is the voltage on the third probe Pad (Pad 3), and the reason is not described herein, so that (V1-V2) is considered to be the voltage drop of Rc3, and in this embodiment, the resistance of all the metal line structures disposed between the two probe pads is the same and is Rs.
In this embodiment, at least one first test set is provided to measure the contact resistance between the probe to be tested and the corresponding probe pad, and the resistance of the metal wire structure, except for the first and the last probes to be tested. Assuming a total of 25 probes to be tested and 25 probe pads corresponding thereto, rc2 and Rc3 (first test group 1), rc4 and Rc5 (first test group 2), rc23 and Rc24 (first test group 12) can be measured by analogy with the same party, i.e., the test results in tip contact resistance Rc at two pads except the first one.
In this embodiment, at least one first test group is set by rational planning, so that the contact resistance between the probe to be tested (except the head and tail probe) and the corresponding probe pad is measured by the Kelvin four-terminal method, and the design is reasonable, ingenious and effective.
Then, as shown in fig. 5, in this embodiment, two adjacent probes to be tested are used as a second test set, and based on the resistance of the metal wire structure, the contact resistances between the first and the last probes to be tested and the corresponding probe pads are measured respectively, which includes:
The two probes to be tested in the second test group are sequentially a fifth probe to be tested and a sixth probe to be tested, and the two probe pads corresponding to the two probes to be tested and inserted into the needle are sequentially a fifth probe Pad (Pad 1 or Pad 25) and a sixth probe Pad (Pad 2 or Pad 24), wherein the fifth probe to be tested is a first probe to be tested or a tail probe to be tested;
applying voltages V5 and V6 to the fifth probe pad and the sixth probe pad respectively by utilizing the fifth probe to be tested and the sixth probe to be tested, namely applying a voltage difference Vf2 to the fifth probe pad and the sixth probe pad to measure a current value I2 of the fifth probe pad or the sixth probe pad;
The contact resistance between the first and the last two probes to be tested and the corresponding probe pad is calculated 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, and the specific process is shown in FIG. 5, comprising:
Contact resistance Rc1= (V5-V6)/I2-Rs-Rc 2 of the first probe to be tested and the fifth probe Pad (Pad 1);
(V5-V6) is Vf2, and since the resistance in this circuit loop includes the contact resistance Rc1 of the first probe to be tested and Pad1, the contact resistance Rc2 and the wire structure resistance Rs (in this embodiment, the resistance values of all the wire structures disposed between the two probe pads are the same, rs) which have been calculated by the foregoing process, and in addition, the measured current values at the fifth probe Pad and the sixth probe Pad are considered to be the same, and thus can be measured and recorded as the current value I2 at only one place.
As shown in FIG. 5, the contact resistance Rc25= (V5-V6)/I2-Rs-Rc 24 of the tail probe to be tested and the corresponding probe pad can be measured in the same way.
In the embodiment, the method for judging the state of the probe tip of the probe to be tested based on the contact resistance of the probe to be tested and the corresponding probe pad comprises the steps of obtaining a preset contact resistance threshold value of the probe tip, judging whether the contact resistance of the probe to be tested and the corresponding probe pad is smaller than the contact resistance threshold value of the probe tip, if yes, the state of the probe to be tested is good, and if not, the state of the probe to be tested is bad and an alarm is given. In the application scenario of the embodiment, as shown in fig. 6, the preset threshold is 10 ohms, and the straight line y=10 of the threshold (rc_spec) can be shown by referring to fig. 6, the contact resistance is compared with the preset threshold, if the contact resistance is smaller than 10 ohms, the state of the needle tip is normal, and if the contact resistance is larger than 10 ohms, the state of the needle tip is abnormal and the alarm is given.
Fig. 6 is a data graph of contact resistance (Rc) of 25pin probes to be tested and corresponding probe pads (pads), wherein the abscissa represents 23 probes to be tested and the ordinate represents corresponding contact resistance values, and in this embodiment, as shown in fig. 6, the tips Rc of all probes are smaller than rc_spec (10 ohms), which indicates that the states of the probes to be tested are good, i.e., all probe card conditions are normal.
In fig. 6, the contact resistances of different colors indicate different needle-out directions (arrangement of needle tips) of the probe to be tested, wherein red indicates the needle tip Rc of the upper needle-out, blue indicates the needle tip Rc of the lower needle-out, the needle-out directions generally have an effect on the contact resistance, the values of the needle tip Rc of the upper needle-out are shown to be larger in the figure, the test structure and the test method of the embodiment are proved to be correct, and the information of the detection method is unified.
In the embodiment, the probes to be tested are needled into different probe pads for contact connection for multiple times, so that the contact resistance values of the probes to be tested and the corresponding probe pads are measured, the contact resistance of the probes to be tested and the probe pads is determined based on the contact resistance values, and the state of the needle tip of the probes to be tested is judged. In particular, as shown in fig. 6, each contact resistance is not a point value, but a section of a plotted value is a value indicating that each probe to be tested is contacted and connected to a different probe pad by multiple needle insertion, so as to measure a plurality of contact resistance values, and a median value of the plurality of contact resistance values is calculated in fig. 6. And each probe to be tested is needled to different probe pads for multiple times to calculate the contact resistance, so that data anomalies possibly caused by accidental errors are avoided, and the reliability of monitoring the condition of the probe tip of the probe card is improved.
Example 2
The embodiment provides a probe card tip condition test structure for realizing the probe card tip condition detection method in the embodiment 1, wherein the probe card tip condition test structure comprises 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 the two probe pads to form a test circuit, the test circuit can refer to fig. 2, and the probes to be tested are respectively needled to the corresponding probe pads and are in contact connection with the corresponding probe pads.
In the embodiment, a plurality of probe pads are determined, and metal wire structures are sequentially arranged between the two probe pads to be connected to form a test circuit, wherein the metal wire structures sequentially arranged between the two probe pads keep identical, namely the resistance values of the metal wire structures sequentially arranged between the two probe pads are identical, the metal wire structures comprise metal wires in at least one metal layer, and the metal wires in the metal layer are at least one of metal wires in straight line routing, metal wires in snake-shaped routing and metal wires in preset path routing.
In summary, the probe card tip condition detection method and the probe card tip condition test structure of the application realize the monitoring of the probe card tip condition by using an electrical test method, thereby reducing the test cost and improving the test accuracy and the test efficiency.
Example 3
The embodiment provides a wafer test method, which is realized by using a probe card tip condition test structure in embodiment 2, and comprises the steps of installing a probe card on a probe station, determining a plurality of probes to be tested of the probe card, controlling a wafer to be tested to enter the probe station, respectively needling the probes to be tested to corresponding probe pads of the wafer to be tested to carry out contact connection, wherein a scribing groove of the wafer to be tested comprises a plurality of metal wire structures and a plurality of probe pads, the metal wire structures are sequentially arranged between the two probe pads to form a test circuit, designing a plurality of test groups based on the position division of the probe pads in the test circuit, measuring the contact resistance of the probes to be tested and the corresponding probe pads, judging the tip state of the probes to be tested based on the contact resistance of the probes to be tested and the corresponding probe pads, if the state of all the probes to be tested is good, adjusting the position of the wafer to be tested, needling the probe card to the test pad of the wafer to be tested to carry out subsequent wafer test, and stopping the subsequent wafer test until the probes to be tested on the probe card pass the state test.
In the embodiment, the metal wire structures sequentially arranged between the two probe pads keep consistent, namely the resistance values of the metal wire structures sequentially arranged between the two probe pads are the same, wherein the metal wire structures comprise metal wires in at least one metal layer, and the metal wires in the metal layer are at least one of metal wires in straight line routing, metal wires in snake-shaped routing and metal wires in preset path routing.
In this embodiment, a plurality of test groups are designed based on the position division of the probe pads in the test circuit, and the contact resistance between the probe to be tested and the corresponding probe pad is measured, including:
1) And measuring the contact resistance of the other probes except the first and the last probes and the corresponding probe pads and the resistance of the metal wire structure by arranging at least one first test group. The method comprises the steps of sequentially arranging 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 in a first test set, arranging a first probe pad, a second probe pad, a third probe pad and a fourth probe pad in sequence corresponding to the four probe pads to be tested, applying voltages V3 and V4 on the second probe pad and the third probe pad respectively by using the second probe to be tested and the third probe to be tested, measuring current values I1 of the second probe pad or the third probe pad, measuring voltage values V1 and V2 of the first probe pad and the fourth probe pad respectively by using the first probe to be tested and the fourth probe to be tested, and calculating to obtain contact resistance of the second probe to be tested and the second probe pad, contact resistance of the third probe to be tested and the third probe pad and resistance of a metal wire structure between adjacent probe pads based on the voltages V3 and V4 and the current values V1 and V2.
2) And taking two adjacent probes to be tested as a second test group, and respectively measuring the contact resistance of the first probe to be tested and the last probe to be tested and the corresponding probe pad by a two-end method based on the resistance of the metal wire structure. The method comprises the steps of sequentially arranging a fifth probe to be tested and a sixth probe to be tested in a second test set, sequentially arranging a fifth probe pad and a sixth probe pad in the two probe to be tested corresponding to the two probes to be tested, wherein the fifth probe to be tested is a first probe to be tested or a tail probe to be tested, respectively applying voltages V5 and V6 on the fifth probe pad and the sixth probe pad by using the fifth probe to be tested and the sixth probe to be tested, measuring a current value I2 of the fifth probe pad or the sixth probe pad, and calculating to obtain the contact resistance of the first probe to be tested and the tail probe to the corresponding probe pad based on the resistance of the metal wire structure, the contact resistance of the sixth probe to be tested and the sixth probe pad, and the voltages V5 and V6 and the current value I2.
In the embodiment, based on the contact resistance of the probe to be tested and the corresponding probe pad, the state of the probe tip of the probe to be tested is judged, which comprises the steps of obtaining a preset contact resistance threshold value of the probe tip, judging whether the contact resistance of the probe to be tested and the corresponding probe pad is smaller than the contact resistance threshold value of the probe tip, if yes, the state of the probe to be tested is good, and if not, the state of the probe to be tested is bad and an alarm is given.
In the embodiment, the probes to be tested are needled to different probe pads for contact connection for multiple times to measure and obtain contact resistance values of the probes to be tested and the corresponding probe pads, and the contact resistance of the probes to be tested and the probe pads is determined based on the contact resistance values to judge the state of the needle tip of the probes to be tested.
In this embodiment, a wafer is further provided for implementing the wafer testing method in this embodiment, where the wafer includes a testing circuit and a performance testing structure, the testing circuit includes a plurality of metal wire structures and a plurality of probe pads, the metal wire structures are sequentially disposed between the two probe pads to form the testing circuit, the testing circuit is disposed in a scribe line of the wafer for performing a probe card tip condition test, and the wafer further includes a performance testing structure for performing an electrical test on device performance on the wafer.
In summary, the application provides an optimized wafer test method based on the probe card tip condition test structure, which realizes that the probe card tip condition test can be performed before the wafer to be tested is subjected to the conventional wafer test, and the subsequent wafer test is performed after the probe tip state passes the test, so that additional equipment and steps are not required, and the accuracy of the subsequent wafer test is ensured. Furthermore, the application also provides a wafer for the wafer testing method, and the test circuit is designed in the scribing groove of the wafer, so that the placing area of the performance testing structure on a chip is not affected, the wafer can be directly used for testing the state of the probe card tip before the performance testing of the device, and the testing accuracy and the detecting efficiency are improved.
The use of certain conventional english terms or letters for the sake of clarity of description of the invention is intended to be exemplary only and not limiting of the interpretation or particular use, and should not be taken to limit the scope of the invention in terms of its possible chinese translations or specific letters.
It should also be noted that in this document, relational terms such as "first" and "second" and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions.

Claims (8)

1.一种探针卡针尖状况检测方法,其特征在于,包括:1. A method for detecting a probe card tip condition, comprising: 确定探针卡的多个待测探针;determining a plurality of probes to be tested of the probe card; 确定多个探针垫,依次在两个所述探针垫之间设置金属线结构以连接形成测试电路;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; 将所述待测探针分别扎针至对应的探针垫进行接触连接;Insert the probes to be tested into corresponding probe pads for contact connection; 基于所述探针垫在测试电路中的位置划分设计多个测试组,量测所述待测探针与对应探针垫的接触电阻,包括:Based on the position of the probe pad in the test circuit, a plurality of test groups are designed to measure the contact resistance between the probe to be tested and the corresponding probe pad, including: 以相邻四个待测探针为第一测试组,通过开尔文四端法量测所述第一测试组的中间两个待测探针与对应探针垫的接触电阻;通过设置至少一个第一测试组,以测得除首尾两个待测探针外其余待测探针与对应探针垫的接触电阻,以及所述金属线结构的电阻;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 the Kelvin four-terminal method; setting at least one first test group to measure the contact resistance between the remaining probes to be tested and the corresponding probe pads, and the resistance of the metal wire structure; 以相邻两个待测探针为第二测试组,基于所述金属线结构的电阻,通过两端法分别测得首尾两个待测探针与对应探针垫的接触电阻;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 two probes to be tested and the corresponding probe pads are respectively measured by a two-terminal method; 基于所述待测探针与对应探针垫的接触电阻,判断所述待测探针的针尖状态。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.根据权利要求1所述的一种探针卡针尖状况检测方法,其特征在于,所述确定多个探针垫,依次在两个所述探针垫之间设置金属线结构以连接形成测试电路,包括:2. A method for detecting the condition of a probe card needle tip according to claim 1, characterized in that the determining of a plurality of probe pads and sequentially setting a metal wire structure between two of the probe pads to connect and form a test circuit comprises: 依次设置在两个所述探针垫之间的金属线结构保持一致,即依次设置在两个所述探针垫之间的金属线结构的阻值相同;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; 其中,所述金属线结构包括至少一个金属层中的金属线;Wherein, the metal wire structure comprises metal wires in at least one metal layer; 所述金属层中的金属线为直线走线的金属线、蛇形走线的金属线以及预设路径走线的金属线中的至少一种。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.根据权利要求1所述的一种探针卡针尖状况检测方法,其特征在于,所述以相邻四个待测探针为第一测试组,量测所述第一测试组的中间两个待测探针与对应探针垫的接触电阻,包括:3. A method for detecting the condition of a probe card tip according to claim 1, characterized in that the step of taking four adjacent probes to be tested as a first test group and measuring the contact resistance between the middle two probes to be tested in the first test group and the corresponding probe pads comprises: 所述第一测试组中的四个待测探针依次为第一待测探针、第二待测探针、第三待测探针、第四待测探针,四个待测探针对应扎针的四个探针垫依次为第一探针垫、第二探针垫、第三探针垫、第四探针垫;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; 利用所述第二待测探针和第三待测探针,分别在所述第二探针垫、第三探针垫上施加电压V3、V4,并测得所述第二探针垫或第三探针垫的电流值I1;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; 利用第一待测探针和第四待测探针,分别量测所述第一探针垫和第四探针垫的电压值V1、V2;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; 基于所述电压V3、V4,电流值I1,以及电压值V1、V2,计算得到所述第二待测探针与第二探针垫的接触电阻、所述第三待测探针与第三探针垫的接触电阻,以及相邻探针垫之间的所述金属线结构的电阻。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. 4.根据权利要求3所述的一种探针卡针尖状况检测方法,其特征在于,所述以相邻两个待测探针为第二测试组,基于所述金属线结构的电阻,分别测得首尾两个待测探针与对应探针垫的接触电阻,包括:4. A method for detecting the condition of a probe card needle tip according to claim 3, characterized in that the contact resistance between the first and last two probes to be tested and the corresponding probe pads is measured based on the resistance of the metal wire structure, taking two adjacent probes to be tested as the second test group, comprising: 所述第二测试组中的两个待测探针依次为第五待测探针、第六待测探针,两个待测探针对应扎针的两个探针垫依次为第五探针垫、第六探针垫;其中,所述第五待测探针为首待测探针或尾待测探针;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; 利用所述第五待测探针和第六待测探针,分别在所述第五探针垫、第六探针垫上施加电压V5、V6,测得所述第五探针垫或第六探针垫的电流值I2;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; 基于所述金属线结构的电阻、第六待测探针与第六探针垫的接触电阻,以及所述电压V5、V6和电流值I2,计算得到首尾两个待测探针与对应探针垫的接触电阻。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. 5.根据权利要求4所述的一种探针卡针尖状况检测方法,其特征在于,基于所述待测探针与对应探针垫的接触电阻,判断所述待测探针的针尖状态,包括:5. A method for detecting the needle tip condition of a probe card according to claim 4, characterized in that judging the needle tip condition of the probe to be tested based on the contact resistance between the probe to be tested and the corresponding probe pad comprises: 获取预设的针尖接触电阻阈值;Obtaining a preset needle tip contact resistance threshold; 判断所述待测探针与对应探针垫的接触电阻是否小于所述针尖接触电阻阈值,若是,则该待测探针的状态良好,否则,则该待测探针的状态不好并报警。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. 6.根据权利要求1所述的一种探针卡针尖状况检测方法,其特征在于,将所述待测探针多次扎针至不同的探针垫进行接触连接,以量测得到多个所述待测探针与对应的探针垫的接触电阻值;6. A method for detecting the condition of a probe card needle tip according to claim 1, characterized in that the probe to be tested is inserted into different probe pads for multiple times for contact connection, so as to measure the contact resistance values between the plurality of probes to be tested and the corresponding probe pads; 基于多个所述接触电阻值,确定所述待测探针与探针垫的接触电阻,用于判断所述待测探针的针尖状态。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. 7.一种探针卡针尖状况测试结构,用于实现权利要求1至权利要求6任意一项所述的探针卡针尖状况检测方法,其特征在于,所述探针卡针尖状况测试结构包括多个金属线结构、多个探针垫和多个待测探针;7. A probe card needle tip condition test structure, used to implement the probe card needle tip condition detection method according to any one of claims 1 to 6, characterized in that the probe card needle tip condition test structure comprises a plurality of metal wire structures, a plurality of probe pads and a plurality of probes to be tested; 所述金属线结构依次设置在两个所述探针垫之间,形成测试电路;The metal wire structure is sequentially arranged between two of the probe pads to form a test circuit; 所述多个待测探针分别扎针至对应的探针垫,与对应的探针垫进行接触连接。The plurality of probes to be tested are respectively inserted into corresponding probe pads to be contacted and connected with the corresponding probe pads. 8.一种晶圆测试方法,利用权利要求7所述的探针卡针尖状况测试结构实现,其特征在于,所述晶圆测试方法包括步骤:8. A wafer testing method, implemented by using the probe card needle tip condition testing structure according to claim 7, characterized in that the wafer testing method comprises the steps of: 在探针台上安装探针卡,确定所述探针卡的多个待测探针;Installing a probe card on a probe station, and determining a plurality of probes to be tested on the probe card; 控制待测晶圆进入探针台,并将所述待测探针分别扎针至所述待测晶圆的对应探针垫进行接触连接;其中,所述待测晶圆的划片槽中包括多个金属线结构和多个探针垫,所述金属线结构依次设置在两个所述探针垫之间,形成测试电路;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; 基于所述探针垫在测试电路中的位置划分设计多个测试组,量测所述待测探针与对应探针垫的接触电阻;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; 基于所述待测探针与对应探针垫的接触电阻,判断所述待测探针的针尖状态: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: 若所有待测探针的状态良好,则调整所述待测晶圆的位置,利用所述探针卡扎针至所述待测晶圆的测试焊盘以进行后续晶圆测试;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; 若存在待测探针的状态报警情况,则停止后续晶圆测试,直至所有探针卡上的待测探针通过状态测试。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.
CN202510517717.1A 2025-04-24 2025-04-24 Probe card needle tip condition detection method, structure, wafer and wafer testing method Active CN120044341B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202510517717.1A CN120044341B (en) 2025-04-24 2025-04-24 Probe card needle tip condition detection method, structure, wafer and wafer testing method

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202510517717.1A CN120044341B (en) 2025-04-24 2025-04-24 Probe card needle tip condition detection method, structure, wafer and wafer testing method

Publications (2)

Publication Number Publication Date
CN120044341A CN120044341A (en) 2025-05-27
CN120044341B true CN120044341B (en) 2025-07-18

Family

ID=95757301

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202510517717.1A Active CN120044341B (en) 2025-04-24 2025-04-24 Probe card needle tip condition detection method, structure, wafer and wafer testing method

Country Status (1)

Country Link
CN (1) CN120044341B (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN120294532A (en) * 2025-06-09 2025-07-11 北京集创北方科技股份有限公司 Adjustment test device and adjustment test method

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104297571A (en) * 2014-09-28 2015-01-21 周峰 Wafer bearing table and Kelvin four-wire test conducting method thereof
CN113671339A (en) * 2021-09-22 2021-11-19 广州粤芯半导体技术有限公司 Apparatus and method for verifying probe abnormality and contact abnormality and wafer testing method

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP3574444B2 (en) * 2002-08-27 2004-10-06 沖電気工業株式会社 Method of measuring contact resistance of probe and method of testing semiconductor device
CN114609569A (en) * 2022-03-21 2022-06-10 长鑫存储技术有限公司 A probe detection method and detection device
CN117289028A (en) * 2023-10-07 2023-12-26 上海积塔半导体有限公司 Resistance testing device, resistance testing method and testing circuit
CN117665544B (en) * 2024-02-01 2024-06-11 合肥晶合集成电路股份有限公司 Wafer acceptance test method
CN118130914A (en) * 2024-03-12 2024-06-04 上海积塔半导体有限公司 Structure and method for testing contact resistance of probe card

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104297571A (en) * 2014-09-28 2015-01-21 周峰 Wafer bearing table and Kelvin four-wire test conducting method thereof
CN113671339A (en) * 2021-09-22 2021-11-19 广州粤芯半导体技术有限公司 Apparatus and method for verifying probe abnormality and contact abnormality and wafer testing method

Also Published As

Publication number Publication date
CN120044341A (en) 2025-05-27

Similar Documents

Publication Publication Date Title
CN120044341B (en) Probe card needle tip condition detection method, structure, wafer and wafer testing method
TWI439704B (en) Resistance measuring structure of bump contact and package substrate containing same
CN107037350A (en) Integrated circuit test structure with supervisory chain and test leads
CN113671339B (en) Device and method for verifying probe abnormality and contact abnormality and wafer test method
US7105856B1 (en) Test key having a chain circuit and a kelvin structure
CN115561527A (en) A system and method for multi-channel small-size and small resistance energization aging and resistance monitoring
US7075307B1 (en) Method and apparatus for detecting shorts on inaccessible pins using capacitive measurements
CN100489549C (en) Wire short /open circuit test set
US10768206B2 (en) Loop-back probe test and verification method
CN113391181A (en) Equipment, wafer structure and method for detecting state of wafer test probe card
JP2004085247A (en) Probe card
CN102128991B (en) Aging test device and test method thereof
CN105652088B (en) The test device of external interface contact impedance
CN207367924U (en) Wafer and its wafer permit Acceptance Tests structure
CN216354196U (en) Semiconductor device and test system
US6894513B2 (en) Multipoint plane measurement probe and methods of characterization and manufacturing using same
JP2014106039A (en) Continuity inspection device and continuity inspection method
CN113506755A (en) Checking graph structure for automatically detecting test channel and test method
TWI282431B (en) Test jig for daisy chain test board
JP2952641B2 (en) Test apparatus and test method for integrated circuit device
CN206930743U (en) WAT test monitor systems
CN114264926B (en) Single-through hole cross-layer electromigration test structure of single-side lead-out voltage test pad
JP5463198B2 (en) Probe card inspection method and inspection system
CN223123208U (en) Probe card electric leakage detection device and wafer acceptance test equipment
JP2005223227A (en) Semiconductor device and semiconductor device evaluation method

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant