CN118443984B - Simple probe station - Google Patents

Abstract

The invention relates to the field of semiconductor testing, in particular to a simple probe station. The simple probe station comprises a probe card installation and adjustment system, a test system and a test system, wherein the probe card installation and adjustment system is used for installing and adjusting a calibration probe card during calibration or installing and adjusting a test probe card during test; the wafer lifting and conveying system is used for conveying, placing and lifting the tested wafer; the upper detection system is used for detecting the lower detection target object; the lower detection system is used for detecting the upper detection target object; and the upper and lower detection and calibration systems are used for respectively carrying out coordinate detection on the upper detection system and the lower detection system during calibration so as to realize calibration and matching of the coordinate systems of the upper detection system and the lower detection system. The simple probe station has a simple structure and low cost, and can realize the functions of the full-automatic probe station such as automatic needle alignment, automatic probe height compensation and the like only by performing early calibration, thereby meeting the full-automatic requirement of the mass production test of the whole wafer.

Description

A simple probe station

Technical Field

The present invention relates to the field of semiconductor testing, and more specifically, to a simple probe station and a corresponding wafer testing method.

Background Art

The probe station, as a high-precision electronic testing equipment, is widely used in the fields of semiconductors, optoelectronics, integrated circuits, and packaging testing. In the wafer inspection process, the probe station, as the main physical carrier, undertakes the key tasks of wafer position transmission and ensuring the physical contact between the wafer and the inspection probe. Its cost and work efficiency have a direct impact on the cost of chip production, so it is an indispensable core equipment for wafer engineering inspection and mass production inspection.

In the classification of probe stations, the fully automatic probe station is an advanced test equipment that can achieve high-speed and high-precision wafer testing. However, due to its high price and equally high use and maintenance costs, the fully automatic probe station does not have an economic advantage in small-scale chip testing. Therefore, a simple probe station has become an important choice to meet such testing needs.

In the prior art, simple probe stations are mainly divided into the following two categories:

The first is the manual probe station, where all wafer position movement, needle insertion and alignment operations need to be completed manually under a microscope, so the test reliability is difficult to guarantee, and it is generally used for engineering testing;

The second is a semi-automatic probe station, which can complete wafer position transmission and needle insertion, but the initial operation still requires manual verification of coordinates and alignment of the needle under a microscope. Since such equipment is not compatible with large-scale probe cards, the test efficiency is relatively low.

In view of the above analysis, the simple probe station of the prior art cannot be connected to large-scale probe cards. Therefore, it has obvious bottlenecks in the simultaneous testing of multiple chips, which directly restricts the improvement of test efficiency. In addition, due to the lack of alignment mechanism between probe cards and wafers, the test process requires too much manual intervention, making it difficult to achieve automated mass production. Therefore, there is an urgent need for a simple probe station that can adapt to large-scale probe cards and is suitable for mass production to meet the testing needs of wafers of different sizes.

Summary of the invention

The purpose of the present invention is to provide a simple probe station and a wafer testing method, so as to solve the problems of low testing efficiency of the simple probe station in the prior art and difficulty in implementing wafer testing with large-scale probe cards.

In order to achieve the above-mentioned object, the present invention provides a simple probe station, including a probe card installation and adjustment system, an upper detection system, a wafer lifting and transmission system, a lower detection system, an upper and lower detection calibration system and a host structure stand:

The probe card installation and adjustment system is installed above the host structure stand and is used to install and adjust the calibration probe card during calibration or install and adjust the test probe card during testing;

The wafer lifting and transporting system is installed below the mainframe structure frame and is used to transport, place and lift the wafer to be tested;

The upper detection system is installed above the mainframe structure platform and is used to detect the detection target below, and the detection target below includes the wafer to be detected;

The lower detection system is installed on the side of the wafer lifting and transmission system, and is used to detect upper detection targets, and the upper detection targets include calibration probe cards and test probe cards;

The upper and lower detection and calibration systems are installed on the side of the main structure stand, and are used to perform coordinate detection on the upper detection system and the lower detection system respectively during calibration, obtain the compensation coordinates between the upper detection system and the lower detection system, and realize calibration matching of the coordinate systems of the upper detection system and the lower detection system.

In some embodiments, the probe card installation and adjustment system includes a probe card installation seat and a probe card installation seat horizontal adjustment block:

The probe card mounting seat is used to mount a calibration probe card or a test probe card;

The probe card mounting seat is mounted above the mainframe structure stand through a probe card mounting seat horizontal adjustment block;

The probe card mounting seat horizontal adjustment block is used to adjust the horizontal direction of the calibration probe card or the test probe card.

In some embodiments, the upper detection system includes an upper camera, an upper camera mounting adjustment seat, and an optical reflector:

The optical reflector is installed above the mainframe structure stand to reflect the light from below to the camera above;

The upper camera is mounted on the upper camera mounting adjustment seat and detects the detection target below through an optical reflector;

The upper camera installation adjustment seat is fixed above the mainframe structure stand to adjust the installation direction of the upper camera.

In some embodiments, the wafer lifting and transporting system includes a wafer carrier, a multi-directional combined motion platform, a motion platform base, and a motion platform base horizontal adjustment block:

The wafer carrier is mounted on a multi-directional combined motion platform;

The multi-directional combined motion platform is installed on the motion platform base, driving the wafer carrier to achieve combined motion in multiple directions;

The motion platform base is installed at the bottom of the mainframe structure frame through the motion platform base horizontal adjustment block;

The motion platform base horizontal adjustment block is used to adjust the horizontal direction of the motion platform base.

In some embodiments, the lower detection system includes a lower camera and a lower camera mounting seat:

The lower camera is mounted on the lower camera mounting seat to detect the detection target above;

The lower camera mounting seat is fixedly mounted on one side of the multi-directional combined motion platform.

In some embodiments, the bottom detection system further includes a displacement sensor and a displacement sensor mounting adjustment seat:

The displacement sensor is installed on the displacement sensor installation and adjustment seat;

The displacement sensor installation adjustment seat is fixedly installed on one side of the multi-directional combined motion platform to adjust the installation position of the displacement sensor.

In some embodiments, the wafer lifting and transfer system further comprises a square:

The angle ruler is used to be placed on the wafer carrier during calibration, and one end of the angle ruler is in contact with the measuring head of the displacement sensor.

In some embodiments, the upper and lower detection and calibration system includes a mask and a mask adjustment seat:

The mask is mounted on the mask adjustment seat and is used to provide a reference coordinate system for calibrating and matching the upper detection system and the lower detection system;

The mask adjustment seat is fixedly mounted on one side of the mainframe structure stand to adjust the installation position of the mask.

Based on the above-mentioned simple probe station, the present invention proposes a wafer testing method, comprising:

Step S1, calibration step:

Perform horizontal calibration on wafer lifting and transfer systems;

Performing horizontal calibration on the probe card installation and adjustment system to obtain the initial loading displacement Z _CP of the wafer lifting and transfer system relative to the probe card installation and adjustment system;

Obtaining an initial Z-direction distance value Z _LC of the wafer lifting and transport system relative to the probe card mounting and adjustment system when the lower detection system and the calibration probe card are in focus;

The compensation coordinates (X _LU , Y _LU ) are obtained through the upper and lower detection calibration systems to achieve calibration matching of the coordinate systems of the upper detection system and the lower detection system;

Obtaining a base height value Z _WT of the upper detection system relative to the wafer lifting and transporting system when the upper detection system and the wafer lifting and transporting system are in focus;

Step S2, testing steps:

Install the test probe card, and adjust the detection system below to focus on the test probe card to obtain the characteristic needle tip of the test probe card;

Place the wafer to be tested, and adjust the upper detection system to focus on the wafer to be tested to obtain the characteristic graphic mark of the wafer to be tested;

The characteristic needle tip and the characteristic graphic mark are matched by coordinate mapping to form an offset strategy, and the test of the wafer under test is completed according to the offset strategy.

In some embodiments, the wafer lifting and transporting system includes a wafer carrier and a multi-directional combined motion platform;

The step S1 of performing horizontal calibration on the wafer lifting and transmission system further includes:

Step S111, driving the Z axis of the multi-directional combined motion platform to rise, so that the wafer carrier appears in the field of view of the upper detection system;

Step S112, by linking the Z axis of the multi-directional combined motion platform and the upper detection system, the upper detection system performs a focusing operation on the surface of the wafer carrier and records the corresponding Z axis value of the multi-directional combined motion platform during focusing;

Step S113, adjusting the X-axis and Y-axis of the multi-directional combined motion platform to expand the focusing range, and repeating step S112 until the Z-axis value fluctuations of all focusing points are less than the specified range.

In some embodiments, the wafer lifting and transporting system further includes a motion platform base horizontal adjustment block;

The step S113 further comprises:

Adjust the horizontal adjustment block of the motion platform base to adjust the horizontal direction of the multi-directional combined motion platform.

In some embodiments, the lower detection system includes a lower camera, a displacement sensor mounting adjustment seat and a displacement sensor:

The step S1 of performing horizontal calibration on the probe card installation and adjustment system to obtain the initial loading displacement of the wafer lifting and transfer system relative to the probe card installation and adjustment system further includes:

Step S121, installing the displacement sensor on the displacement sensor mounting adjustment seat, and adjusting the displacement sensor mounting adjustment seat until the measuring head of the displacement sensor is higher than the wafer carrier plane by a certain distance;

Step S122, placing the angle ruler on the wafer carrier, with one end of the angle ruler in contact with the measuring head of the displacement sensor, and recording the first displacement value P ₁ of the displacement sensor at this time;

Step S123, removing the angle ruler from the wafer carrier;

Step S124, installing the calibration probe card to a corresponding position of the probe card installation and adjustment system;

Step S125, driving the X-axis, Y-axis and Z-axis of the multi-directional combined motion platform to make the measuring head of the displacement sensor contact with the probe head of the calibration probe card;

Step S126, driving the X-axis and Y-axis of the multi-directional combined motion platform so that the displacement sensor scans the probe head area and records all measured displacement values;

Step S128, when all displacement value fluctuations obtained by measurement are less than the specified range, the second displacement value P ₂ of the displacement sensor at this time is recorded, and the first Z-axis value Z ₁ of the multi-directional combined motion platform is recorded at the same time;

Step S129 , calculating and obtaining the Z-axis initial loading displacement value Z _CP of the multi-directional combined motion platform when the wafer carrier contacts the probe head, and the corresponding expression is Z _CP =P ₂ −P ₁ +Z ₁ .

In some embodiments, the probe card mounting adjustment system further includes a probe card mounting seat horizontal adjustment block;

After step S126, the method further includes:

Step S127, adjusting the horizontal adjustment block of the probe card mounting seat to adjust the horizontal direction of the calibration probe card, and repeating step S126 until the fluctuations of all displacement values measured in step S126 are less than the specified range.

In some embodiments, the step S1 of obtaining an initial Z-direction distance value of the wafer lifting and transport system relative to the probe card mounting adjustment system when the lower detection system and the calibration probe card are focused further includes:

Step S132, driving the X-axis, Y-axis and Z-axis of the multi-directional combined motion platform to make the probe head of the calibration probe card enter the field of view of the detection system below;

Step S133, linking the Z axis of the multi-directional combined motion platform and the lower detection system, the lower detection system completes the focusing operation on the probe head, and records the corresponding second Z axis value Z ₂ of the multi-directional combined motion platform when the focusing is completed;

Step S134, calculate and obtain the Z-direction distance Z _LC between the wafer carrier and the probe head when the lower detection system completes focusing on the probe head, as the initial Z-direction distance value of the wafer lifting and transport system relative to the probe card installation and adjustment system, and the corresponding expression is Z _LC =Z ₂ -Z _CP .

In some embodiments, before step S132, the method further includes:

Step S131, remove the displacement sensor.

In some embodiments, the top and bottom detection and calibration system includes a reticle;

The step S1 further includes:

Step S141, installing the mask so that the mask appears in the field of view of the upper detection system;

Step S142: the upper detection system completes the focusing operation on the mask pattern and records the first horizontal offset coordinate (X ₁ , Y ₁ ) between the mask pattern and the center of the field of view of the upper detection system.

Step S143, driving the X-axis, Y-axis and Z-axis of the multi-directional combined motion platform so that the mask enters the field of view of the detection system below;

Step S144, linking the Z axis of the multi-directional combined motion platform and the lower detection system, the lower detection system completes the focusing operation on the mask pattern, and records the second horizontal offset coordinate (X ₂ , Y ₂ ) between the mask pattern and the center of the field of view of the lower detection system;

Step S145, recording the X-axis value and the Y-axis value of the multi-directional combined motion platform to form a third coordinate (X ₃ , Y ₃ );

Step S146, calculate and obtain the compensation coordinates (X _LU , Y _LU ) of the horizontal coordinate system of the lower detection system mapped to the horizontal coordinate system of the upper detection system, and the corresponding expression is (X _LU , Y _LU )=(X ₁ -X ₂ +X ₃ , Y ₁ -Y ₂ +Y ₃ );

Step S147, removing the mask.

In some embodiments, the upper and lower detection and calibration system further includes a mask adjustment seat;

The step S142 further comprises:

Adjust the mask adjustment seat to adjust the installation position of the mask so that the upper detection system focuses on the mask pattern.

In some embodiments, when the upper detection system and the wafer lifting and transporting system are focused in step S1, the base height value of the upper detection system relative to the wafer lifting and transporting system is obtained, further comprising:

Step S151, driving the Z axis of the multi-directional combined motion platform to rise, so that the wafer carrier appears in the field of view of the upper detection system;

Step S152: By linking the Z axis of the multi-directional combined motion platform and the upper detection system, the upper detection system performs focusing operation on the surface of the wafer carrier, and records the corresponding Z axis value of the multi-directional combined motion platform during focusing as the basic height value Z _WT of the upper detection system relative to the wafer carrier surface of the wafer lifting and transmission system.

In some embodiments, in step S2, adjusting the lower detection system to focus the test probe card to obtain the characteristic needle tip of the test probe card further includes:

Step S22, driving the X-axis, Y-axis and Z-axis of the multi-directional combined motion platform, using the lower detection system to find the characteristic needle tip of the test probe card for focusing, and recording the corresponding Z-axis value of the multi-directional combined motion platform during focusing;

Step S23, adjust the X-axis and Y-axis of the multi-directional combined motion platform, use the detection system below to find other characteristic needle tips of the test probe card, repeat step S22 until the Z-axis value fluctuation of the focus of all characteristic needle tips is less than the specified range, and record the X-axis value and Y-axis value of all characteristic needle tips.

In some embodiments, the wafer lifting and transporting system further includes a motion platform base horizontal adjustment block;

The step S23 further comprises:

Adjust the horizontal adjustment block of the motion platform base to adjust the horizontal direction of the multi-directional combined motion platform.

In some embodiments, in step S2, adjusting the upper detection system to focus on the wafer under test to obtain the characteristic graphic mark of the wafer under test further includes:

Step S25, driving the X-axis, Y-axis and Z-axis of the multi-directional combined motion platform, using the upper detection system to find the characteristic pattern mark of the wafer to be tested for focusing, and recording the corresponding Z-axis value Z _W of the multi-directional combined motion platform during focusing;

Step S26, according to the corresponding Z-axis value Z _W of the multi-directional combined motion platform in step S25 and the basic height value Z _WT of the upper detection system relative to the wafer lifting and transmission system, obtain the thickness T _W of the wafer to be measured, corresponding to the expression T _W =Z _WT -Z _W ;

Step S27, combining the initial Z-direction distance Z _LC of the wafer lifting and transporting system relative to the probe card installation and adjustment system and the wafer thickness T _W of step S26, determining the Z-axis value Z ₀ of the multi-directional combined motion platform when the test probe contacts the wafer under test, corresponding to the expression Z ₀ =Z _LC -T _W ;

Step S28, driving the X-axis, Y-axis, Z-axis and θ-axis of the multi-directional combined motion platform, using the upper detection system to find all characteristic graphic marks of the wafer under test, and recording the X-axis values and Y-axis values of all characteristic graphic marks.

In some embodiments, the step S2 performs coordinate mapping and matching between the feature needle tip and the feature graphic mark to form an offset strategy, and completes the test of the wafer under test according to the offset strategy, further comprising:

Step S29, using the X-axis value and the Y-axis value obtained by the characteristic needle tip and the characteristic graphic mark, combined with the compensation coordinates (X _LU , Y _LU ) obtained in the calibration step, coordinate mapping matching is performed, and according to the acupuncture strategy, the XY offset of each acupuncture is determined to form an offset strategy;

Step S210, completing acupuncture and testing according to the offset strategy obtained in step S29;

Step S211: After the test is completed, replace the wafer to be tested.

The simple probe station and the corresponding wafer testing method provided by the present invention have a simple probe station structure and low cost. During the testing process, only preliminary calibration is required to realize the functions of the fully automatic probe station such as automatic needle alignment and automatic compensation of probe height, thereby meeting the fully automatic requirements of automated mass production testing of the entire wafer.

The present invention provides a simple probe station and a wafer testing method, which significantly improves the testing efficiency and reduces the testing cost, and specifically has the following beneficial effects:

1) It is constructed using low-cost components, which is not only economical but also easy to replicate. The entire device does not use expensive sensor components (such as laser sensors, etc.), but has the same functions as the fully automatic probe station, such as automatic needle alignment and automatic compensation of probe height, which greatly reduces the cost. At the same time, its calibration process is also very clear, which is easy to replicate and promote;

2) The simple probe station can be adapted to large-scale probe cards and is not limited by the size of the probe card. Therefore, it can be adapted to large-scale probe cards to meet the testing requirements of multiple chips on the same side;

3) The simple probe station has the functions of probe card leveling, automatic needle alignment, and automatic compensation of probe height. It can be seen from the test process that the probe card leveling is the basic function. The characteristic value is obtained through the early calibration steps, thereby realizing the functions of automatic needle alignment and automatic compensation of probe height, and improving the accuracy and efficiency of the test;

4) The simple probe station can automatically complete the automated mass production test of the entire wafer. During the actual mass production test process, only the probe card and the upper and lower wafers need to be manually adjusted during the first installation. The rest of the operations can be automatically completed by program adaptation, which greatly reduces manual intervention and improves the automation level of mass production testing of the entire wafer.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other features, properties and advantages of the present invention will become more apparent through the following description in conjunction with the accompanying drawings and embodiments, in which the same reference numerals always represent the same features, wherein:

FIG1 discloses a schematic diagram of the structure of a simple probe station system during calibration according to an embodiment of the present invention;

FIG2 discloses a schematic diagram of the structure of a simple probe station system during testing according to an embodiment of the present invention;

FIG3 discloses a schematic structural diagram of a calibration probe card according to an embodiment of the present invention;

FIG. 4 discloses a flow chart of a wafer testing method based on a simple probe station according to an embodiment of the present invention.

The meanings of the reference numerals in the figures are as follows:

1. Calibration probe card;

1a Probe card fixing structure;

1b probe card substrate;

1c probe head;

2 probe card mounting seat;

3. Probe card mounting seat horizontal adjustment block;

4 square ruler;

5. Wafer carrier;

6. Displacement sensor;

7. Displacement sensor installation adjustment seat;

8. Multi-directional combined motion platform;

9 motion platform base;

10. Motion platform base level adjustment block;

11 optical reflector;

12 Upper camera mounting adjustment seat;

13. Top camera;

14 masks;

15. Mask adjustment seat;

16 bottom camera;

17 lower camera mounting seat;

18. Mainframe structure stand;

19 test probe card;

20 wafers under test.

DETAILED DESCRIPTION

In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the invention and are not used to limit the invention.

The present invention proposes a simple probe station, which, through special structural design and calibration process setting, makes the low-cost simple probe station close to the fully automatic probe station in terms of core functions (including automatic needle alignment, automatic compensation of probe height and automatic needle insertion), thereby greatly improving the test efficiency and saving the test cost.

The present invention provides a simple probe station, including a probe card installation and adjustment system, an upper detection system, a wafer lifting and transmission system, a lower detection system, an upper and lower detection calibration system, and a host structure stand:

The probe card installation and adjustment system is installed above the host structure stand and is used to install and adjust the calibration probe card during calibration or install and adjust the test probe card during testing;

The wafer lifting and transporting system is installed below the mainframe structure frame and is used to transport, place and lift the wafer to be tested;

The upper detection system is installed above the mainframe structure platform and is used to detect the detection target below, and the detection target below includes the wafer to be detected;

The lower detection system is installed on the side of the wafer lifting and transmission system, and is used to detect upper detection targets, and the upper detection targets include calibration probe cards and test probe cards;

The upper and lower detection and calibration systems are installed on the side of the mainframe structure platform, and are used to perform coordinate detection on the upper detection system and the lower detection system respectively during calibration, obtain the compensation coordinates between the upper detection system and the lower detection system, and realize the calibration and matching of the coordinate systems of the upper detection system and the lower detection system;

The host structure frame is used to carry the above system.

FIG1 discloses a schematic diagram of the structure of a simple probe station system during calibration according to an embodiment of the present invention, and FIG2 discloses a schematic diagram of the structure of a simple probe station system during testing according to an embodiment of the present invention. As shown in FIG1 and FIG2, a simple probe station proposed by the present invention includes a probe card installation and adjustment system, an upper detection system, a wafer lifting and transmission system, a lower detection system, an upper and lower detection and calibration system, and a host structure stand:

After the probe card is installed on the machine, it cannot ensure that the probe tip plane and the wafer plane are sufficiently parallel, which will lead to the inability to use it normally. This is also a key factor that must be considered before wafer testing. To solve this problem, in this embodiment, the present invention specially designs a probe card installation and adjustment system, which can effectively complete the calibration of the probe card and the leveling and adjustment operation of the test probe card in actual use, ensuring the accuracy and reliability of the test process.

Furthermore, the probe card installation and adjustment system includes a probe card installation seat 2 and a probe card installation seat horizontal adjustment block 3:

The probe card mounting seat 2 is used to mount the calibration probe card 1 or the test probe card 19;

The probe card mounting seat 2 is mounted above the mainframe structure stand 18 through the probe card mounting seat horizontal adjustment block 3;

The probe card mounting seat horizontal adjustment block 3 is used to adjust the horizontal direction of the calibration probe card 1 or the test probe card 19 .

FIG3 discloses a schematic structural diagram of a calibration probe card according to an embodiment of the present invention. The calibration probe card 1 shown in FIG3 includes a probe card fixing structure 1a, a probe card substrate 1b, and a probe head 1c:

The probe card fixing structure 1a is used to fix the calibration probe card 1 on the probe card mounting seat 2;

The probe card substrate 1b is used to install the probe head 1c;

The probe head 1c is a whole flat ceramic substrate, which is used to provide a calibration reference.

During the calibration process, the calibration probe card 1 is used for precise calibration to ensure the test accuracy of the simple probe station. When performing the test, the calibration probe card 1 needs to be replaced with the test probe card 19 actually used.

Furthermore, the upper detection system includes an upper camera 13, an upper camera mounting adjustment seat 12 and an optical reflector 11:

The optical reflector 11 is installed above the mainframe structure stand 18 to reflect the light from below to the camera 13 above;

The upper camera 13 is mounted on the upper camera mounting and adjusting seat 12, and detects the detection target below through the optical reflector 11;

The upper camera installation adjustment seat 12 is fixed above the main structure stand 18 to adjust the installation direction of the upper camera 13.

In this embodiment, the upper camera mounting adjustment seat 12 is an upper camera X-direction mounting adjustment seat, which is used to fix the upper camera 13 and adjust the X-direction of the upper camera 13 .

In this embodiment, the optical reflector 11 is a 45° optical reflector. This setting can convert the focus adjustment of the upper camera 13 in the Z direction to the X direction, which can ensure that the upper detection system occupies the minimum Z direction space and avoid interference with the lower detection system.

In this embodiment, the upper camera 13 can be a finished high-precision industrial camera combination with a pixel resolution of less than 1 μm, which is used for identifying and detecting the marks of the wafer to be tested.

In order to meet the higher demand for the same number of tests, the number of probes on large-scale probe cards ranges from hundreds to tens of thousands. The increase in the number of probes also leads to an increase in the cost of probe cards. However, this does not mean that the probes can achieve a 1:1 complete match with the wafer pad (pin pad). Therefore, in order to balance the cost of the probe card and the test efficiency, the present invention uses a wafer lifting and transmission system to transport the wafer horizontally, and reduces the number of probes used through a partitioned test scheme to ensure the smooth progress of the test.

Furthermore, the wafer lifting and transporting system includes a wafer carrier 5, a square 4, a multi-directional combined motion platform 8, a motion platform base 9 and a motion platform base horizontal adjustment block 10:

The wafer carrier 5 is mounted on a multi-directional combined motion platform 8;

The multi-directional combined motion platform 8 is mounted on the motion platform base 9, and drives the wafer carrier 5 to realize combined motion in multiple directions;

The motion platform base 9 is installed at the bottom of the main structure stand 18 through the motion platform base horizontal adjustment block 10;

The motion platform base horizontal adjustment block 10 is used to adjust the horizontal direction of the motion platform base 9 .

Furthermore, the angle ruler 4 is placed on the wafer carrier 5 during calibration, and one end of the angle ruler 4 is in contact with the measuring head of the displacement sensor 6 .

In this embodiment, the angle ruler 4 is a marble triangle, which is only used during calibration.

In order to accurately measure other targets using the displacement sensor 6, the position of the displacement sensor 6 must be clear. The marble triangle is selected as an auxiliary tool mainly based on its excellent flatness and easy availability. The marble triangle is placed on the wafer carrier 5, and its extended part can be used as a reference for the displacement sensor 6 to measure, thereby ensuring the accuracy of the measurement result.

In this embodiment, the wafer carrier 5 can be any finished product in the prior art, has a high degree of compatibility and adaptability, and can be provided with functions such as vacuum adsorption.

The multi-directional combined motion platform 8 can adopt various general motion platforms existing in the current prior art, and only needs to meet the motion requirements of being able to flexibly adjust multiple directions.

In this embodiment, the multi-directional combined motion platform 8 is a high-precision XYZθ combined motion platform, which can realize precise motion adjustment in the X, Y, Z and θ directions, wherein XY are horizontal orthogonal directions. In FIGS. 1 and 2 , the X direction is the left-right direction; the Y direction is the direction perpendicular to the paper; the Z direction is the vertical up-down direction; and the θ direction is the rotation angle with the Z axis as the rotation axis.

For example, in terms of precision indicators, the high-precision XYZθ combined motion platform has demonstrated excellent performance. The platform's accuracy in the XY direction reaches ±1μm, which is the micron level, showing extremely high positioning accuracy; the accuracy in the Z direction is ±2μm, which also maintains a high level of precision requirements; the accuracy in the θ direction reaches ±5arcsec, which is the arc second level, reflecting its accuracy in rotational motion.

Furthermore, the lower detection system includes a lower camera 16 and a lower camera mounting seat 17:

The lower camera 16 is mounted on a lower camera mounting seat 17 to detect the detection target above;

The lower camera mounting seat 17 is fixed on the Z axis on one side of the multi-directional combined motion platform 8 .

In this embodiment, the lower camera 16 may be a finished product, for example, a dual-rate high-precision industrial camera combination with a pixel resolution of less than 1 μm, which is used for probe card marking and needle tip recognition.

Furthermore, the lower detection system further includes a displacement sensor 6 and a displacement sensor mounting and adjusting seat 7:

The displacement sensor 6 is mounted on a displacement sensor mounting and adjusting seat 7;

The displacement sensor installation adjustment seat 7 is fixed on one side of the multi-directional combined motion platform 8 to adjust the installation position of the displacement sensor 6.

The displacement sensor 6 is only used during calibration, and the displacement sensor 6 may be a finished product, such as a contact-type high-precision displacement sensor with an absolute accuracy of ±1 μm.

Optionally, the displacement sensor 6 may be GT2-P12KL and CL-P030 of Keyence. Compared with the laser displacement sensor, the contact displacement sensor has greater economic advantages.

In this embodiment, the displacement sensor mounting adjustment seat 7 is a displacement sensor Z-direction mounting adjustment seat, which is fixed on the Z-axis on one side of the multi-directional combined motion platform 8 to adjust the Z-direction position of the displacement sensor 6 .

It should be noted that the spatial layout of the displacement sensor 6, the upper camera 13 and the lower camera 16 can be arbitrarily combined and arranged under the premise of ensuring that they do not interfere with each other during the use of the equipment, and will not cause any impact on the execution of the calibration and testing process in the present invention.

Since the probe card and wafer belong to different mechanisms, if the XY coordinate systems of the two are not accurately matched, it will be impossible to accurately predict which pad on the wafer the probe will contact after the wafer is lifted. This is not allowed in operation, so the consistency and accuracy of the coordinate systems of the two must be ensured.

The present invention uses an upper and lower detection and calibration system to achieve accurate matching of the coordinate system. The core principle is to use the lower detection system that is relatively fixed to the wafer position to obtain the layout information of the probe, and at the same time, use the upper detection system that is relatively fixed to the probe card position to obtain the layout information of the wafer pad. On this basis, the coordinates of the upper and lower detection systems are further matched.

The present invention introduces the upper and lower detection calibration system as the reference coordinate system to ensure that the upper and lower detection systems can be in the same reference coordinate system. By calibrating the upper and lower detection systems respectively, the compensation coordinate information can be obtained, and then the relationship between the two can be established to ensure that the upper and lower detection systems can be accurately in the same coordinate system.

Furthermore, the upper and lower detection and calibration system includes a mask 14 and a mask adjustment seat 15:

The mask 14 is mounted on the mask adjustment seat 15 and is used to provide a reference coordinate system for calibrating and matching the upper detection system and the lower detection system;

The mask adjustment seat 15 is fixedly mounted on one side of the mainframe structure stand 18 to adjust the installation position of the mask 14 .

The mask 14 is only used during calibration, so that the upper detection system and the lower detection system can observe the same reference at the same time.

In this embodiment, the mask 14 is a glass mask having the characteristics of a transparent substrate, and its surface is covered with a high-precision photolithography pattern to provide a reference coordinate system, and can be a finished product device.

In this embodiment, the mask adjustment seat 15 is a mask Z-direction adjustment seat, which is used to fix the mask 14 and adjust the mask 14 in the Z direction.

The simple probe station proposed in the present invention has the following significant advantages over the prior art:

1) Compared with manual probe station:

The traditional manual probe station completely relies on the operator's manual operation under a microscope in terms of wafer position movement, needle insertion, and alignment operations. This manual-dependent method not only makes it difficult to ensure test reliability, but is also usually limited to engineering test scenarios. The present invention can automate wafer position movement, needle insertion, and alignment operations, significantly improving the reliability and efficiency of the test.

2) Compared with semi-automatic probe station:

Although the semi-automatic probe station has realized the automation of wafer position transmission and needle insertion to a certain extent, the operator still needs to manually check the coordinates and perform needle alignment under a microscope when using it for the first time. In addition, due to the incompatibility with large-scale probe cards, the test efficiency of the semi-automatic probe station is relatively low. The present invention does not require manual needle alignment, realizes fully automated needle alignment operation, and can be adapted to large-scale probe cards, thereby greatly improving the test efficiency.

3) Compared with the fully automatic probe station:

Although the fully automatic probe station is more comprehensive and advanced in function and performance, its high cost and complex structure make it not suitable for all production scenarios. The present invention uses conventional sensors and structures, which are relatively low-cost and easy to copy, and are particularly suitable for production scenarios that do not require frequent changes in product types. Therefore, while ensuring test accuracy and efficiency, the present invention also takes into account the requirements of cost and production flexibility.

Based on the above-mentioned simple probe station, the present invention proposes a wafer testing method based on the simple probe station, comprising:

Step S1, calibration step:

Perform horizontal calibration on wafer lifting and transfer systems;

Performing horizontal calibration on the probe card installation and adjustment system to obtain the initial loading displacement Z _CP of the wafer lifting and transfer system relative to the probe card installation and adjustment system;

Obtaining an initial Z-direction distance value Z _LC of the wafer lifting and transport system relative to the probe card mounting and adjustment system when the lower detection system and the calibration probe card are in focus;

The compensation coordinates (X _LU , Y _LU ) are obtained through the upper and lower detection calibration systems to achieve calibration matching of the coordinate systems of the upper detection system and the lower detection system;

Obtaining a base height value Z _WT of the upper detection system relative to the wafer lifting and transporting system when the upper detection system and the wafer lifting and transporting system are in focus;

Step S2, testing steps:

Install the test probe card;

Adjust the detection system below to focus the test probe card to obtain the characteristic needle tip of the test probe card;

Place the wafer to be tested;

Adjust the upper detection system to focus on the wafer to be tested and obtain the characteristic graphic mark of the wafer to be tested;

The characteristic needle tip and the characteristic graphic mark are matched by coordinate mapping to form an offset strategy, and the test of the wafer under test is completed according to the offset strategy.

The specific steps of the wafer testing method proposed in the present invention are analyzed and explained in detail and in depth in combination with the structure of a simple probe station.

The parallelism between the probe card tip plane and the wafer plane is crucial to the stability and accuracy of the wafer testing process. During the wafer testing process, the wafer carrier carries the wafer and realizes the relative movement between the wafer and the probe card through precise motion control. The parallelism between the probe card tip plane and the wafer plane directly affects the force distribution during the test. If the two are not parallel, the wafer will be subjected to uneven force during the wafer top-up process. This uneven force will cause the probes in some areas to fail to contact the wafer correctly, which will affect the coverage and accuracy of the test. At the same time, due to the uneven force, the probe that contacts first may pierce the wafer due to continuous pressure, or even cause the probe itself to be damaged by overpressure, which is a great damage to both the test equipment and the wafer.

Therefore, the parallelism between the probe card tip plane and the wafer plane has a decisive influence on the reliability of the test results. In step S1, the wafer lifting and transmission system and the probe card installation and adjustment system are horizontally calibrated to ensure the parallelism between the probe card tip plane and the wafer plane.

The wafer lifting and transmission system is horizontally calibrated in step S1, which mainly includes step S11, installing and horizontally adjusting the multi-directional combined motion platform 8.

The step S11 further comprises:

Step S111, driving the Z-axis of the multi-directional combined motion platform 8 to rise, so that the wafer carrier 5 appears in the field of view of the upper camera 13;

Step S112, by linking the Z axis of the multi-directional combined motion platform 8 and the upper camera 13, the upper camera 13 performs a focusing operation on the surface of the wafer carrier 5, and records the corresponding Z axis value of the multi-directional combined motion platform 8 during focusing;

Step S113, adjusting the X-axis and Y-axis of the multi-directional combined motion platform 8 to expand the focusing range, and repeating step S112 until the Z-axis value fluctuations of all focusing points are less than the specified range.

Optionally, step S113 is followed by step S114, adjusting the horizontal adjustment block 10 of the motion platform base, adjusting the horizontal direction of the multi-directional combined motion platform 8 and repeating steps S112 and S113 until the Z-axis value fluctuation of all focus points is ensured to be less than a specified range, for example, 5 μm.

The step S1 of performing horizontal calibration on the probe card installation and adjustment system to obtain the initial loading displacement Z _CP of the wafer lifting and transport system relative to the probe card installation and adjustment system mainly includes:

Step S12 , completing the horizontal calibration of the calibration probe card 1 , obtaining and recording the Z-axis value Z _CP of the multi-directional combined motion platform 8 when the wafer carrier 5 contacts the probe head 1 c .

The step S12 further comprises:

Step S121, installing the displacement sensor 6 on the displacement sensor mounting and adjusting seat 7, and adjusting the displacement sensor mounting and adjusting seat 7 until the measuring head of the displacement sensor 6 is higher than the plane of the wafer carrier 5 by a certain distance, for example, about 1 mm;

Step S122, placing the angle ruler 4 on the wafer carrier 5, and ensuring that one end of the angle ruler 4 is in contact with the measuring head of the displacement sensor 6, and recording the first displacement value P ₁ of the displacement sensor 6 at this time;

Step S123, removing the angle ruler 4 from the wafer carrier 5;

Step S124, installing the calibration probe card 1 to a corresponding position of the probe card installation and adjustment system;

Step S125, driving the X-axis, Y-axis and Z-axis of the multi-directional combined motion platform 8 to make the measuring head of the displacement sensor 6 contact the probe head 1c of the calibration probe card 1, and ensure that the displacement value at this time is greater than the first displacement value _P1 recorded in step S122;

Step S126, driving the X-axis and Y-axis of the multi-directional combined motion platform 8 so that the displacement sensor 6 scans the probe head 1c area and records all measured displacement values in detail;

Step S128, when the displacement value is stable, that is, when the fluctuation of all measured displacement values is less than the specified range, record the second displacement value P ₂ of the displacement sensor at this time, and record the first Z-axis value Z ₁ of the multi-directional combined motion platform 8;

Step S129 , by combining the three values recorded in step S122 and step S128 , calculate the Z-axis initial loading displacement value Z _CP of the multi-directional combined motion platform 8 when the wafer carrier contacts the probe head, and the corresponding expression is Z _CP =P ₂ −P ₁ +Z ₁ .

Optionally, after step S126 and before step S128, the following further steps are included:

Step S127, adjust the horizontal adjustment block 3 of the probe card mounting seat to adjust the horizontal direction of the calibration probe card 1, and repeat step S126 until the fluctuation of all displacement values measured in step S126 is less than the specified range, such as 2 μm.

When the probe contacts the wafer, in order to ensure the stability of the electrical connection, the contact displacement needs to be appropriately increased. However, the increase in contact displacement is not without limit and must be controlled within a reasonable range, otherwise, excessive displacement may cause damage to the wafer or probe due to overvoltage. Therefore, in the calibration step, the initial loading displacement value Z _CP , the initial Z-direction distance value Z _LC and the base height value Z _WT are set, wherein the base height value Z _WT is used to determine the thickness of the wafer to be tested in the subsequent test process, and then combined with the initial loading displacement value Z _CP and the initial Z-direction distance value Z _LC , the precise distance between the wafer carrier plane and the needle tip can be determined.

In this way, before the actual test, the initial loading height during the test process can be set. By accurately controlling the initial loading height, the stability of the electrical connection when the probe contacts the wafer can be ensured, and damage to the wafer or the probe can be effectively avoided.

Wherein, the step S1 obtains the initial Z-direction distance value Z _LC of the wafer lifting and transport system relative to the probe card installation adjustment system when the lower detection system and the calibration probe card are focused, and mainly includes step S13, determining the Z-direction distance Z _LC between the wafer carrier 5 and the focusing target probe head 1c when the lower camera 16 is focused.

The step S13 further comprises:

Step S131, removing the displacement sensor 6;

Step S132, driving the X-axis, Y-axis and Z-axis of the multi-directional combined motion platform 8, so that the probe head 1c of the calibration probe card 1 enters the field of view of the lower camera 16;

Step S133, linking the Z axis of the multi-directional combined motion platform 8 and the lower camera 16, the lower camera 16 completes the focusing operation on the probe head 1c, and records the corresponding second Z axis value _Z2 of the multi-directional combined motion platform 8 when the focusing is completed;

Step S134: Calculate the Z-direction distance Z _LC between the wafer carrier 5 and the focusing target probe head 1c when the lower camera 16 completes focusing on the probe head 1c by using the initial loading displacement Z _CP obtained in step S129 and the second Z-axis value Z ₂ obtained in step S133, as the initial Z-direction distance value of the wafer lifting and transport system relative to the probe card installation and adjustment system, and the corresponding expression is Z _LC =Z ₂ -Z _CP .

In this embodiment, the displacement sensor 6 is removed before step S132 . However, in actual operation, other appropriate times may be selected to remove the displacement sensor 6 according to specific circumstances.

Wherein, in step S1, the compensation coordinates (X _LU , Y _LU ) are obtained by the upper and lower detection calibration systems to achieve calibration matching of the coordinate systems of the upper detection system and the lower detection system, which mainly includes:

Step S14, obtaining the compensation coordinates (X _LU , Y _LU ) of the horizontal coordinate system of the lower camera 16 mapped to the horizontal coordinate system of the upper camera 13;

The step S14 further comprises:

Step S141, installing the mask 14 so that the mask 14 appears in the field of view of the upper camera 13;

Step S142 , the upper camera 13 completes the focusing operation on the pattern of the mask 14 , and records the first horizontal offset coordinate (X ₁ , Y ₁ ) between the pattern of the mask 14 and the center of the field of view of the upper camera 13 ;

Step S143, driving the X-axis, Y-axis and Z-axis of the multi-directional combined motion platform 8 so that the mask 14 enters the field of view of the lower camera 16;

Step S144, linking the Z axis of the multi-directional combined motion platform 8 and the lower camera 16, the lower camera 16 completes the focusing operation on the pattern of the mask 14, and records the second horizontal offset coordinate ( _X2 , _Y2 ) between the pattern of the mask 14 and the center of the field of view of the lower camera 16;

Step S145, recording the X-axis value and the Y-axis value of the multi-directional combined motion platform to form a third coordinate (X ₃ , Y ₃ );

Step S146, calculate and obtain the compensation coordinates (X _{LU , Y LU ) of the lower camera horizontal coordinate system mapped to the upper camera horizontal coordinate system through the first horizontal offset coordinates (X 1 , Y 1 ) of step S142 , the second horizontal offset coordinates (X 2 , Y 2 ) of step S144} and the third coordinates (X ₃ , Y ₃ ) of step S145 , and the corresponding expression is (X _LU , Y _LU )=(X ₁ -X ₂ +X ₃ , Y ₁ -Y ₂ +Y ₃ );

Step S147 , removing the mask 14 .

Optionally, the step S142 further includes:

The mask adjustment seat 15 is adjusted to adjust the installation position of the mask 14 so that the upper camera 13 focuses on the pattern of the mask 14 .

Wherein, when the upper detection system and the wafer lifting and transporting system are focused in step S1, the base height value Z _WT of the upper detection system relative to the wafer lifting and transporting system is obtained, which mainly includes:

Step S15 , obtaining a basic height value Z _WT of the thickness of the object on the surface of the wafer carrier 5 measured by the upper camera 13 .

The step S15 further comprises:

Step S151, driving the Z-axis of the multi-directional combined motion platform 8 to rise, so that the wafer carrier 5 appears in the field of view of the upper camera 13;

Step S152, by linking the Z axis of the multi-directional combined motion platform 8 and the upper camera 13, the upper camera 13 focuses on the surface of the wafer carrier 5, and records the corresponding Z axis value Z _WT of the multi-directional combined motion platform 8 during focusing, which serves as the basic height value for the upper camera to measure the thickness of the object on the surface of the wafer carrier, and is used to determine the thickness of the wafer to be measured in the subsequent test process.

Based on the calibration value obtained in step S1, a test step in step S2 is performed.

The testing step of step S2 further includes:

Step S21, installing the test probe card 19;

After step S21, the method further includes adjusting the lower detection system to focus the test probe card to obtain the characteristic needle tip of the test probe card.

The step S2 of adjusting the lower detection system to focus the test probe card to obtain the characteristic needle tip of the test probe card further includes:

Step S22, driving the X-axis, Y-axis and Z-axis of the multi-directional combined motion platform 8, using the lower camera 16 to find the characteristic needle tip of the test probe card 19 for focusing, and recording the corresponding Z-axis value of the multi-directional combined motion platform 8 during focusing;

Step S23, adjust the X-axis and Y-axis of the multi-directional combined motion platform 8, use the lower camera 16 to find other characteristic needle tips of the test probe card 19, repeat step S22 until the Z-axis value fluctuation of the focus of all characteristic needle tips is less than the specified range, and record the X-axis value and Y-axis value of all characteristic needle tips.

At this time, the characteristic distance between the wafer carrier 5 and the test probe card 19 is the initial Z-direction distance value Z _LC of the wafer lifting and transporting system relative to the probe card installation and adjustment system;

Optionally, the step S23 further comprises:

The horizontal adjustment block 10 of the motion platform base is adjusted to adjust the horizontal direction of the multi-directional combined motion platform 8, and steps S22 to S23 are repeated until the Z-axis value fluctuation of all characteristic needle tip focus points is less than a specified range, such as 5 μm.

After step S23, the method further comprises:

Step S24 , placing the wafer 20 to be tested.

After step S24, the method further includes adjusting the upper detection system to focus on the wafer to be tested to obtain characteristic graphic marks of the wafer to be tested.

In step S2, adjusting the upper detection system to focus the wafer under test to obtain the characteristic graphic mark of the wafer under test further includes:

Step S25, driving the X-axis, Y-axis and Z-axis of the multi-directional combined motion platform 8, using the upper camera 13 to find the characteristic pattern mark of the wafer 20 to be tested for focusing, and recording the corresponding Z-axis value Z _W of the multi-directional combined motion platform 8 during focusing;

Step S26, according to the corresponding Z-axis value Z _W of the multi-directional combined motion platform 8 in step S25 and the basic height value Z _WT of the upper camera relative to the surface of the wafer carrier, the thickness T _W of the wafer to be measured is obtained, and the corresponding expression is T _W =Z _WT -Z _W ;

Step S27, combining the initial Z-direction distance Z _LC of the wafer lifting and transporting system relative to the probe card installation and adjustment system and the wafer thickness T _W of step S26, determining the Z-axis displacement Z ₀ of the multi-directional combined motion platform 8 when the test probe contacts the wafer 20, corresponding to the expression Z ₀ =Z _LC -T _W ;

Step S28, drive the X-axis, Y-axis, Z-axis and θ-axis of the multi-directional combined motion platform 8, use the upper camera 13 to find all characteristic graphic marks of the wafer 20 under test, and record the X-axis values and Y-axis values of all characteristic graphic marks.

In the step S2, coordinate mapping and matching of the characteristic needle tip and the characteristic graphic mark is performed to form an offset strategy, and the test of the wafer under test is completed according to the offset strategy, further comprising:

Step S29, using the X-axis value and the Y-axis value obtained by the characteristic needle tip and the characteristic graphic mark, combined with the compensation coordinates (X _LU , Y _LU ) obtained in the calibration step (i.e., the compensation coordinates mapped from the horizontal coordinate system of the lower camera to the horizontal coordinate system of the upper camera), coordinate mapping matching is performed, and according to the acupuncture strategy, the XY offset of each acupuncture is determined to form an offset strategy;

Step S210, completing the needle insertion and testing according to the offset strategy obtained in step S29, ensuring that the target area on the wafer can be accurately tested;

Step S211 , after the test is completed, replace the wafer 20 to be tested.

Repeat steps S28 to S211 to perform wafer mass production testing.

The piercing strategy is a pre-decision made by the probe card (especially the large-scale probe card) during the wafer testing process. The core purpose of the piercing strategy is to determine how many times the probe card can fully cover all the chips on the entire wafer after piercing.

The needle-piercing strategy is essentially an offset coordinate queue, and its core idea is to assign appropriate wafer pad coordinates to each needle-piercing round. By performing needle-piercing operations in a preset order, this strategy ensures that all chips can be fully covered in the optimal test order, thereby ensuring the accuracy and effectiveness of the test.

The root cause of this strategy is that it is difficult to achieve an accurate one-to-one correspondence between the number of probes on the probe card and the number of wafer pads, which usually involves high costs.

For example, suppose there are 1,000 chips distributed on a wafer, and the probe card only supports testing 200 chips at the same time. In order to achieve comprehensive coverage of all chips, the wafer needs to be moved at least five times for probing. Of course, this is just an example of a simple mathematical calculation. In fact, in real working conditions, the complex relationship between the chip layout and the probe card layout needs to be considered. Therefore, the probing strategy cannot be covered by a simple division relationship, but needs to be formulated by comprehensively considering multiple factors. The formulation of the probing strategy is a prerequisite for the design and manufacture of the probe card, which determines the basic structure and testing capabilities of the probe card. At the same time, the probing strategy further affects the subsequent test production process.

Based on the coordinate information provided by the acupuncture strategy, an offset strategy is formulated in combination with the coordinate compensation strategy to ensure the smooth implementation of subsequent acupuncture and other testing work.

The offset strategy is used to adjust the contact position between the test probe and the wafer under test. First, the multi-directional combined motion platform needs to be driven to reach the predetermined Z-axis zero displacement value Z ₀ to ensure that the test probe is in the best working state when it contacts the wafer under test. On this basis, according to the actual needs of each needle insertion, the XY offset of the motion platform is adjusted to achieve fine adjustment of the relative position between the test probe and the wafer under test.

It should be pointed out that the wafer 20 under test can not only be placed and removed manually, but also an automated wafer handling robot can be added to further reduce the interference of human factors, especially in the upper and lower wafer links, thereby reducing the potential impact of human factors on the overall work efficiency.

However, in view of the relatively high cost investment of the automated wafer handling robot and the fact that the device has no direct relationship with the realization of the core calibration function, this article will no longer provide a detailed description and discussion of the device. However, this does not mean that the present invention is limited in terms of functional expansion. In fact, the present invention is fully capable of docking with other external automated mechanisms, thereby further approaching the functional realization of a fully automatic probe station.

In addition, the high-precision XYZθ combined motion platform also supports manual adjustment. Alternatively, other automated mechanisms can be introduced for (auxiliary) adjustment based on actual needs to ensure maximum overall work efficiency and accuracy.

Although the above methods are illustrated and described as a series of actions for simplicity of explanation, it should be understood and appreciated that these methods are not limited by the order of the actions, because according to one or more embodiments, some actions may occur in a different order and/or concurrently with other actions from those illustrated and described herein or not illustrated and described herein but understandable to those skilled in the art.

The present invention provides a simple probe station and a wafer testing method, which significantly improves the testing efficiency and reduces the testing cost, and specifically has the following beneficial effects:

1) It is constructed using low-cost components, which is not only economical but also easy to replicate. The entire device does not use expensive sensor components (such as laser sensors, etc.), but has the same functions as the fully automatic probe station, such as automatic needle alignment and automatic compensation of probe height, which greatly reduces the cost. At the same time, its calibration process is also very clear, which is easy to replicate and promote;

2) The simple probe station can be adapted to large-scale probe cards and is not limited by the size of the probe card. Therefore, it can be adapted to large-scale probe cards to meet the testing requirements of multiple chips on the same side;

3) The simple probe station has the functions of probe card leveling, automatic needle alignment, and automatic compensation of probe height. It can be seen from the test process that the probe card leveling is the basic function. The characteristic value is obtained through the early calibration steps, thereby realizing the functions of automatic needle alignment and automatic compensation of probe height, and improving the accuracy and efficiency of the test;

4) The simple probe station can automatically complete the automated mass production test of the entire wafer. During the actual mass production test process, only the probe card and the upper and lower wafers need to be manually adjusted during the first installation. The rest of the operations can be automatically completed by program adaptation, which greatly reduces manual intervention and improves the automation level of mass production testing of the entire wafer.

As shown throughout this application, unless the context clearly indicates an exception, the words "a", "an", "a kind" and/or "the" do not refer to the singular, but also include the plural. Generally speaking, the terms "include" and "comprise" only indicate the inclusion of the steps and elements that have been clearly identified, and these steps and elements do not constitute an exclusive list, and the method or device may also include other steps or elements.

In the description of the present invention, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

The above embodiments are provided for persons familiar with the art to implement or use the present invention. Personnel familiar with the art can make various modifications or changes to the above embodiments without departing from the inventive concept of the present invention. Therefore, the protection scope of the present invention is not limited to the above embodiments, but should be the maximum scope that conforms to the innovative features.

Claims (20)

1. The simple probe station is characterized by comprising a probe card installation and adjustment system, an upper detection system, a wafer lifting and transmission system, a lower detection system, an upper and lower detection and calibration system and a host structure rack:

The probe card installation and adjustment system is arranged above the host structure rack and is used for installing and adjusting the calibration probe card during calibration or installing and adjusting the test probe card during test;

The wafer lifting and conveying system is arranged below the rack of the host structure and is used for conveying, placing and lifting the tested wafer;

the upper detection system is arranged above the host structure rack and is used for detecting a lower detection target object, wherein the lower detection target object comprises a detected wafer;

The lower detection system is arranged at the side of the wafer lifting and conveying system and is used for detecting an upper detection target object, wherein the upper detection target object comprises a calibration probe card and a test probe card;

The upper and lower detection and calibration system is arranged at the side of the rack of the host structure and used for respectively carrying out coordinate detection on the upper detection system and the lower detection system during calibration, acquiring compensation coordinates between the upper detection system and the lower detection system and realizing calibration matching of coordinate systems of the upper detection system and the lower detection system;

wherein, probe card installs governing system, including probe card mount pad:

the probe card mounting seat is used for mounting a calibration probe card or a test probe card;

the upper detection system comprises an upper camera and an optical reflector:

the optical reflector is arranged above the host structure rack and reflects the light below to the upper camera;

The upper camera detects a detection target object below through an optical reflector;

the lower detection system comprises a lower camera and a lower camera mounting seat:

the lower camera is arranged on the lower camera mounting seat and used for detecting the detection target above;

the lower camera mounting seat is fixedly arranged on one side of the multidirectional combined motion platform;

the wafer lifting and conveying system comprises a wafer carrying disc and a multidirectional combined motion platform:

the wafer carrying disc is arranged on the multidirectional combined motion platform;

The multidirectional combined motion platform drives the wafer carrying disc to realize combined motion in multiple directions;

The upper and lower detection and calibration system comprises a mask plate and a mask plate adjusting seat:

The mask plate is arranged on the mask plate adjusting seat and used for providing a reference coordinate system and carrying out calibration matching on the upper detection system and the lower detection system;

The mask plate adjusting seat is fixedly arranged on one side of the host structure rack and is used for adjusting the installation position of the mask plate.

2. The simplified probe station of claim 1, wherein the probe card mounting adjustment system further comprises a probe card mount level adjustment block:

the probe card mounting seat is arranged above the host structure rack through a probe card mounting seat horizontal adjusting block;

And the probe card mounting seat horizontal adjusting block is used for adjusting the horizontal direction of the calibration probe card or the test probe card.

3. The simplified probe station of claim 1, wherein the upper detection system further comprises an upper camera mount adjustment mount:

the upper camera is arranged on the upper camera installation adjusting seat;

the upper camera installation adjusting seat is fixed above the main machine structure bench and is used for adjusting the installation direction of the upper camera.

4. The simplified prober of claim 1, wherein the wafer lift and transfer system further comprises a motion stage base and a motion stage base horizontal adjustment block:

the multidirectional combined motion platform is arranged on the motion platform base;

the motion platform base is arranged at the bottom of the rack of the host structure through a motion platform base horizontal adjusting block;

the motion platform base horizontal adjusting block is used for adjusting the horizontal direction of the motion platform base.

5. The simplified probe station of claim 1, wherein the lower detection system further comprises a displacement sensor and a displacement sensor mounting adjustment block:

The displacement sensor is arranged on the displacement sensor installation adjusting seat;

the displacement sensor mounting and adjusting seat is fixedly arranged on one side of the multidirectional combined motion platform, and the mounting position of the displacement sensor is adjusted.

6. The simplified prober of claim 5, wherein the wafer lift and transfer system further comprises an angle square:

the angle square is used for being placed on the wafer carrying disc during calibration, and one end of the angle square is contacted with the measuring head of the displacement sensor.

7. A wafer testing method based on the simple probe station implementation of any one of claims 1 to 6, comprising:

Step S1, a calibration step:

Performing horizontal calibration on a wafer lifting and conveying system;

Performing horizontal calibration on the probe card installation and adjustment system to obtain initial loading displacement Z _CP of the wafer lifting and transmission system relative to the probe card installation and adjustment system;

when the lower detection system and the calibration probe card are focused, an initial Z-direction distance value Z _LC of the wafer lifting and transmission system relative to the probe card installation and adjustment system is obtained;

the compensation coordinate (X _LU,Y_LU) is obtained through the upper and lower detection and calibration systems, so that the calibration matching of the coordinate systems of the upper detection system and the lower detection system is realized;

Acquiring a basic height value Z _WT of the upper detection system relative to the wafer lifting and conveying system when the upper detection system and the wafer lifting and conveying system are focused;

step S2, testing:

installing a test probe card, and adjusting a lower detection system to focus the test probe card to obtain a characteristic needle point of the test probe card;

Placing a tested wafer, and adjusting the upper detection system to focus the tested wafer to obtain a characteristic pattern mark of the tested wafer;

And carrying out coordinate mapping matching on the characteristic needle points and the characteristic graphic marks to form an offset strategy, and completing the test of the tested wafer according to the offset strategy.

8. The method of claim 7, wherein,

The wafer lifting and conveying system comprises a wafer carrying disc and a multidirectional combined motion platform;

in the step S1, performing horizontal calibration on the wafer lifting and conveying system further includes:

step S111, driving the Z axis of the multidirectional combined motion platform to ascend so that the wafer carrier plate appears in the field of view of the upper detection system;

Step S112, focusing operation is carried out on the surface of the wafer carrier disc by the upper detection system through linkage of the Z axis of the multidirectional combined motion platform and the upper detection system, and corresponding Z axis values of the multidirectional combined motion platform during focusing are recorded;

Step S113, adjusting the X axis and the Y axis of the multi-direction combined motion platform to enlarge the focusing range, and repeatedly executing step S112 until the Z axis value fluctuation of all focusing points is smaller than the designated range.

9. The wafer testing method of claim 8, wherein the wafer lift and transfer system further comprises a motion stage base level adjustment block;

The step S113 further includes:

and adjusting the horizontal adjusting block of the base of the motion platform to adjust the horizontal direction of the multi-direction combined motion platform.

10. The wafer testing method of claim 7, wherein the lower inspection system comprises a lower camera, a displacement sensor mounting adjustment block, and a displacement sensor:

In the step S1, the probe card installation and adjustment system is horizontally calibrated, and initial loading displacement of the wafer lifting and transmission system relative to the probe card installation and adjustment system is obtained, and the method further includes:

step S121, mounting a displacement sensor on a displacement sensor mounting and adjusting seat, and adjusting the displacement sensor mounting and adjusting seat until a measuring head of the displacement sensor is higher than the plane of the wafer carrier disc by a certain distance;

Step S122, placing the angle square on the wafer carrier disc, enabling one end of the angle square to be in contact with a measuring head of the displacement sensor, and recording a first displacement value P ₁ of the displacement sensor at the moment;

step S123, removing the angle square from the wafer carrier;

step S124, installing a calibration probe card to the corresponding position of the probe card installation adjusting system;

Step S125, the measuring head of the displacement sensor is contacted with the probe head of the calibration probe card by driving the X axis, the Y axis and the Z axis of the multidirectional combined motion platform;

step S126, driving an X axis and a Y axis of the multi-direction combined motion platform so that the displacement sensor scans the probe head area and records all measured displacement values;

Step S128, when all measured displacement value fluctuation is smaller than a specified range, recording a second displacement value P ₂ of the displacement sensor at the moment, and simultaneously recording a first Z-axis value Z ₁ of the multi-direction combined motion platform;

Step S129, calculating a Z-axis initial loading displacement value Z _CP of the multidirectional combined motion platform when the wafer carrier contacts the probe head according to the first displacement value P ₁ recorded in step S122, the second displacement value P ₂ recorded in step S128 and the first Z-axis value Z ₁.

11. The wafer testing method of claim 10, wherein the probe card mounting adjustment system further comprises a probe card mount level adjustment block;

After the step S126, further includes:

And S127, adjusting the probe card mounting seat horizontal adjusting block to adjust the horizontal direction of the calibration probe card, and repeating the step S126 until all measured displacement value fluctuations in the step S126 are smaller than a specified range.

12. The method according to claim 10, wherein the step S1 of obtaining the initial Z distance value of the wafer lift and transfer system relative to the probe card mounting adjustment system when the lower inspection system and the calibration probe card are in focus, further comprises:

Step S132, driving the X axis, the Y axis and the Z axis of the multi-direction combined motion platform to enable the probe head of the calibration probe card to enter the view field of the lower detection system;

Step S133, linking a Z axis of the multidirectional combined motion platform and a lower detection system, completing focusing operation on the probe head by the lower detection system, and recording a corresponding second Z axis value Z ₂ of the multidirectional combined motion platform when focusing is completed;

And step S134, calculating and obtaining the Z-direction distance Z _LC between the wafer carrier disc and the probe head when the lower detection system finishes focusing on the probe head according to the initial loading displacement value Z _CP and the second Z-axis value Z ₂, wherein the Z-direction distance Z _LC is used as an initial Z-direction distance value of the wafer lifting and conveying system relative to the probe card installation adjusting system.

13. The method according to claim 12, further comprising, prior to step S132:

and S131, removing the displacement sensor.

14. The wafer testing method of claim 7, wherein the upper and lower inspection calibration system comprises a reticle;

in the step S1, calibration matching of the coordinate systems of the upper detection system and the lower detection system is achieved through the upper and lower detection calibration systems, and the method further includes:

Step S141, installing a mask so that the mask appears in the field of view of the upper detection system;

Step S142, the upper detection system completes focusing operation on the mask pattern, and a first horizontal offset coordinate (X ₁,Y₁) between the mask pattern and the center of the visual field of the upper detection system is recorded;

step S143, driving an X axis, a Y axis and a Z axis of the multi-direction combined motion platform to enable the mask plate to enter the view field of the lower detection system;

step S144, linking the Z axis of the multi-direction combined motion platform and the lower detection system, completing focusing operation on the mask pattern by the lower detection system, and recording a second horizontal offset coordinate (X ₂,Y₂) between the mask pattern and the center of the visual field of the lower detection system;

Step S145, recording an X-axis value and a Y-axis value of the multi-direction combined motion platform to form a third coordinate (X ₃,Y₃);

Step S146, calculating to obtain a compensation coordinate (X _LU,Y_LU) of the lower detection system horizontal coordinate system mapped to the upper detection system horizontal coordinate system through the first horizontal offset coordinate (X ₁,Y₁) of step S142, the second horizontal offset coordinate (X ₂,Y₂) of step S144, and the third coordinate (X ₃,Y₃) of step S145;

And step S147, removing the mask.

15. The wafer testing method of claim 14, wherein the upper and lower inspection calibration system further comprises a reticle adjustment seat;

the step S142 further includes:

And adjusting the mask plate adjusting seat to adjust the mounting position of the mask plate so that the upper detection system focuses on the mask plate pattern.

16. The method according to claim 8, wherein the step S1 of obtaining the basic height value of the upper detecting system relative to the wafer lift and transfer system when the upper detecting system and the wafer lift and transfer system are in focus further comprises:

Step S151, driving the Z axis of the multidirectional combined motion platform to ascend so that the wafer carrier disc appears in the field of view of the upper detection system;

and S152, performing focusing operation on the surface of the wafer carrier by the upper detection system through linkage of the Z axis of the multidirectional combined motion platform and the upper detection system, and recording a Z axis value corresponding to the multidirectional combined motion platform during focusing, wherein the Z axis value is used as a basic height value Z _WT of the upper detection system relative to the surface of the wafer carrier of the wafer lifting and conveying system.

17. The wafer testing method according to claim 7, wherein adjusting the lower inspection system to focus the test probe card in step S2 to obtain the characteristic tip of the test probe card, further comprises:

S22, driving an X axis, a Y axis and a Z axis of the multi-direction combined motion platform, searching a characteristic needle point of the test probe card by using a lower detection system to focus, and recording a Z axis value corresponding to the multi-direction combined motion platform during focusing;

and S23, adjusting the X axis and the Y axis of the multi-direction combined motion platform, searching other characteristic needle points of the test probe card by using a lower detection system, repeatedly executing the step S22 until the Z axis value fluctuation of the focusing points of all the characteristic needle points is smaller than a specified range, and recording the X axis value and the Y axis value of all the characteristic needle points.

18. The wafer testing method of claim 17, wherein the wafer lift and transfer system further comprises a motion stage base level adjustment block;

The step S23 further includes:

and adjusting the horizontal adjusting block of the base of the motion platform to adjust the horizontal direction of the multi-direction combined motion platform.

19. The method according to claim 7, wherein adjusting the upper inspection system to focus the wafer to be inspected in step S2 to obtain the feature pattern mark of the wafer to be inspected, further comprises:

S25, driving an X axis, a Y axis and a Z axis of the multi-direction combined motion platform, searching a characteristic pattern mark of a tested wafer by using an upper detection system to focus, and recording a Z axis value Z _W corresponding to the multi-direction combined motion platform during focusing;

Step S26, obtaining the thickness T _W of the wafer to be tested according to a Z-axis value Z _W corresponding to the multidirectional combined motion platform in step S25 and a basic height value Z _WT of the upper detection system relative to the wafer lifting and conveying system;

Step S27, an initial Z-direction distance value Z _LC of the integrated wafer lifting and conveying system relative to the probe card installation and adjustment system and a wafer thickness T _W of step S26 are combined, and when a test probe is in contact with a tested wafer, a Z-axis value Z ₀ of the multidirectional combined motion platform is determined;

And S28, driving an X axis, a Y axis, a Z axis and a theta axis of the multi-direction combined motion platform, searching all characteristic pattern marks of the tested wafer by using an upper detection system, and recording X axis values and Y axis values of all the characteristic pattern marks.

20. The method according to claim 7, wherein in the step S2, the feature tip and the feature pattern mark are subjected to coordinate mapping matching to form an offset strategy, and the wafer to be tested is tested according to the offset strategy, and further comprising:

S29, carrying out coordinate mapping matching by using an X-axis value and a Y-axis value obtained by the characteristic needle point and the characteristic graph mark and combining the compensation coordinate (X _LU,Y_LU) obtained in the calibration step, and determining XY offset of each needle insertion according to the needle insertion strategy to form an offset strategy;

step S210, needling and testing are completed according to the offset strategy obtained in the step S29;

and step S211, after the test is completed, replacing the tested wafer.