Detection method

Abstract

The invention relates to the technical field of semiconductor detection, and provides a detection method. The detection method comprises the following steps: moving a laser displacement sensor to enable the laser displacement sensor to sequentially pass through each pit on a tray station; acquiring a reference height Zpj of the chip in the reference pit in a normal state, or acquiring a chip height Zic of a single chip and a pit height Zl of the pit; acquiring a detection height corresponding to the chip in the actual pit, and recording the detection height as an actual chip height Zp; obtaining a chip existence parameter Zyw according to the actual chip height Zp and the reference height Zpj, or obtaining a chip existence parameter Zyw according to the actual chip height Zp, the chip height Zic and the pit height Zl; and comparing the chip existence parameter Zyw with a preset threshold value to judge the state of the chip in the actual pit. The detection method provided by the invention is used for detecting the state of the chip in the carrier disc, the detection efficiency is effectively improved on the basis of meeting chip detection at different stations, and the universality is wider.

Description

Technical Field

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

[0002] In chip detection, laser scanning is used to measure the chip, and due to its fast, non-contact and high-precision characteristics, it is widely used in the field of industrial online measurement.

[0003] In related technologies, after obtaining the surface information of an object, it is often necessary to measure various data such as distance, angle, plane, etc. Although accurate calculation results can be obtained, there are many steps involved and many parameters that need to be considered, which leads to lower measurement efficiency. Summary of the invention

[0004] Based on this, it is necessary to provide a detection method for detecting the state of the chip in the carrier tray, which can effectively improve the detection efficiency and have wider versatility while meeting the chip detection requirements of different workstations.

[0005] A detection method for detecting a chip state, the detection method comprising the following steps:

[0006] Move the laser displacement sensor so that it passes through each pit position on the tray station in turn;

[0007] Obtain a reference height Zpj of a chip in a reference pit in a normal state, or obtain a chip height Zic of a single chip and a pit height Zl of the pit;

[0008] Get the detection height corresponding to the chip in the actual pit and record it as the actual chip height Zp;

[0009] Obtaining a chip presence parameter Zyw according to the actual chip height Zp and the reference height Zpj, or obtaining a chip presence parameter Zyw according to the actual chip height Zp, the chip height Zic and the pit height Zl;

[0010] The chip presence parameter Zyw is compared with a preset threshold to determine the chip status in the actual pit.

[0011] It is understandable that by moving the laser displacement sensor relative to the tray station, the laser displacement sensor can be moved to different tray stations to meet the chip detection at different stations and reduce the detection cost. At the same time, when performing detection, the reference height when the chip is in a normal state and the actual chip height in the actual state can be compared to obtain the chip parameter Zyw, and the chip state in the actual pit can be determined based on the chip parameter Zyw. Alternatively, the chip parameter Zyw can be obtained based on the chip height and the pit height, as well as the actual chip height when the chip is in the actual state, so as to judge the chip state in the actual pit. In other words, compared with the need to consider the influence of multiple parameters such as distance, angle and flatness in the related art, the detection method provided in this embodiment only needs to consider the detection height, is not constrained by other parameters, and is not constrained by the chip size, simplifies the detection steps, and makes the overall detection efficiency higher and more versatile.

[0012] In some embodiments, obtaining a reference height Zpj of a chip in a reference pit in a normal state includes:

[0013] When the laser displacement sensor emits a point laser, the height of the tray station is calibrated;

[0014] Select n reference points in the reference pit;

[0015] The laser displacement sensor is moved to above each of the reference points, and a point laser is emitted to the corresponding reference point to obtain the detection height of each of the reference points. The reference height Zpj is the average value of the detection heights corresponding to each of the reference points.

[0016] In some embodiments, obtaining the chip presence parameter Zyw according to the actual chip height Zp and the reference height Zpj includes:

[0017] The chip has a parameter Zyw=Zp-Zpj.

[0018] In some embodiments, comparing the chip presence parameter Zyw with a preset threshold to determine the chip status in the actual pit includes:

[0019] Select m actual detection points in the actual pit position, and obtain the actual detection height corresponding to each of the actual detection points;

[0020] Obtaining an actual height difference Zm between each of the actual detection heights;

[0021] The chip presence parameter Zyw and the actual height difference value Zm are respectively compared with the corresponding preset thresholds to determine the chip status in the actual pit; wherein the preset thresholds include a material presence threshold and a height difference threshold.

[0022] In some embodiments, the detection height is the straight-line distance between the laser displacement sensor and the detection surface; the chip state includes a no-material state, a material state, a stacked-material state, and a warped-material state;

[0023] The step of comparing the chip presence parameter Zyw and the actual height difference value Zm with the corresponding preset thresholds to determine the chip status in the actual pit includes:

[0024] Comparing the actual height difference value Zm with the height difference threshold;

[0025] When the actual height difference value Zm matches the height difference threshold, the chip presence parameter Zyw is compared with the material threshold; wherein, when the chip presence parameter Zyw is greater than the material threshold, the actual pit is in the no-material state; when the chip presence parameter Zyw is less than the material threshold, the actual pit is in the stacked material state; when the chip presence parameter Zyw matches the material threshold, the actual pit is in the normal state;

[0026] When the actual height difference value Zm does not match the height difference threshold, the actual pit position is in the warping state.

[0027] In some embodiments, the detection height is the straight-line distance between the plane on which the carrier plate is placed and the detection surface; the chip state includes a no-material state, a material state, a stacked-material state, and a warped-material state;

[0028] The step of comparing the chip presence parameter Zyw and the actual height difference Zm with the corresponding preset thresholds to determine the chip status in the actual pit position also includes:

[0029] Comparing the actual height difference value Zm with the height difference threshold;

[0030] When the actual height difference value Zm matches the height difference threshold, the chip presence parameter Zyw is compared with the material threshold; wherein, when the chip presence parameter Zyw is greater than the material threshold, the actual pit is in the stacking state; when the chip presence parameter Zyw is less than the material threshold, the actual pit is in the no-material state; when the chip presence parameter Zyw matches the material threshold, the actual pit is in the normal state;

[0031] When the actual height difference value Zm does not match the height difference threshold, the actual pit position is in the warping state.

[0032] In some embodiments, obtaining the chip presence parameter Zyw according to the actual chip height Zp, the chip height Zic and the pit height Zl includes:

[0033] The chip has a parameter Zyw=100%×|Zp-Zl| / Zic.

[0034] In some embodiments, comparing the chip presence parameter Zyw with a preset threshold to determine the chip status in the actual pit includes:

[0035] Select m actual detection points in the actual pit position, and obtain the actual detection height corresponding to each of the actual detection points;

[0036] Obtaining an actual height difference Zm between each of the actual detection heights;

[0037] According to the actual height difference Zm and the chip height, a warpage parameter Zh=Zm / Zic is obtained.

[0038] In some embodiments, the preset thresholds include a material warpage threshold, a material-free threshold, a material-existing threshold, and a material stacking threshold; the chip status includes a material-free state, a normal state, a material stacking state, and a material warpage state;

[0039] The comparing the chip presence parameter Zyw with a preset threshold to determine the chip status in the actual pit also includes:

[0040] Comparing the warping parameter Zh with the warping threshold;

[0041] When the material warping parameter Zh matches the material warping threshold, the chip presence / absence parameter Zyw is compared with the no-material threshold, the material presence threshold and the stacking threshold respectively; wherein, when the chip presence / absence parameter Zyw matches the no-material threshold, the actual pit position is in the no-material state; when the chip presence / absence parameter Zyw matches the material presence threshold, the actual pit position is in the normal state; when the chip presence / absence parameter Zyw matches the stacking threshold, the actual pit position is in the stacking state;

[0042] When the material warping parameter Zh does not match the material warping threshold, the actual pit position is in the material warping state.

[0043] In some embodiments, obtaining the actual height difference Zm between the actual detected heights includes:

[0044] The maximum value Zmax and the minimum value Zmin of each of the actual detected heights are obtained, and then the actual height difference Zm=Zmax-Zmin; wherein m is greater than 1.

[0045] In some embodiments, comparing the chip presence parameter Zyw with a preset threshold to determine the chip status in the actual pit also includes:

[0046] Obtain a height set Z corresponding to actual detection heights at different positions in the actual pit;

[0047] Combining the actual chip height with the height set Z to obtain a height offset ratio Zz;

[0048] Wherein, Zz=100%×|Z-Zp| / Z.

[0049] In some embodiments, the preset threshold includes an offset threshold, a no-material threshold, a material threshold, and a stacking threshold; the chip status includes a no-material status, a normal status, a stacking status, and a warping status;

[0050] The comparing the chip presence parameter Zyw with a preset threshold to determine the chip status in the actual pit also includes:

[0051] Comparing the height offset ratio Zz with the offset threshold;

[0052] When the height offset ratio Zz matches the offset threshold, the chip presence / absence parameter Zyw is compared with the no-material threshold, the material presence threshold and the stacking threshold respectively; wherein, when the chip presence / absence parameter Zyw matches the no-material threshold, the actual pit position is in the no-material state; when the chip presence / absence parameter Zyw matches the material presence threshold, the actual pit position is in the normal state; when the chip presence / absence parameter Zyw matches the stacking threshold, the actual pit position is in the stacking state;

[0053] When the height offset ratio Zz does not match the offset threshold, the actual pit position is in the warping state.

[0054] In some embodiments, obtaining the detection height corresponding to the chip in the actual pit and recording it as the actual chip height Zp includes:

[0055] When the laser displacement sensor emits a point laser, the center point of the actual pit is selected as the actual detection point, the laser displacement sensor is moved above the actual detection point, and the point laser is emitted to obtain the actual detection height, and the actual detection height is the actual chip height Zp;

[0056] or,

[0057] When the laser displacement sensor emits point laser, multiple actual detection points in the actual pit are selected, the laser displacement sensor is moved to pass through each of the actual detection points respectively, and point laser is emitted to each of the actual detection points to obtain the actual detection height corresponding to each of the actual detection points. The actual chip height Zp is the average value of each of the actual detection heights.

[0058] In some of the embodiments, when the laser displacement sensor emits a line laser, the detection heights corresponding to multiple points within the scanning range corresponding to the actual pit position after the line laser line scan are obtained, and the actual chip height Zp is the average value of each of the detection heights. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the conventional technology, the drawings required for use in the embodiments or the conventional technology descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0060] Figure 1 A first flow chart of the detection method provided in Example 1 of the present application;

[0061] Figure 2 A second flow chart of the detection method provided in Example 1 of the present application;

[0062] Figure 3 A first flow chart of the detection method provided in Example 2 of the present application;

[0063] Figure 4 A second flow chart of the detection method provided in Example 2 of the present application;

[0064] Figure 5 This is a flow chart of the detection method provided in Example 3 of the present application. DETAILED DESCRIPTION

[0065] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0066] It should be noted that when a component is referred to as being "fixed to" or "disposed on" another component, it may be directly on the other component or there may also be a central component. When a component is considered to be "connected to" another component, it may be directly connected to the other component or there may be a central component at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used in the specification of this application are for illustrative purposes only and do not represent the only implementation method.

[0067] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0068] In the present application, unless otherwise clearly specified and limited, a first feature being “above” or “below” a second feature may mean that the first feature is directly in contact with the second feature, or the first feature and the second feature are indirectly in contact through an intermediate medium. Moreover, a first feature being “above”, “above” or “above” a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being “below”, “below” or “below” a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0069] Unless otherwise defined, all technical and scientific terms used in the specification of this application have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application. The term "and / or" used in the specification of this application includes any and all combinations of one or more related listed items.

[0070] It should be noted in advance that the match referred to below means being the same as the corresponding numerical threshold, or falling within the corresponding range threshold; the mismatch referred to below means being different from the corresponding numerical threshold, or not falling within the corresponding range threshold, and may be greater than or less than the corresponding numerical threshold or range threshold.

[0071] Embodiment 1

[0072] See also Figure 1 As shown, the present application provides a detection method, comprising the following steps:

[0073] Move the laser displacement sensor so that it passes through each pit position on the tray station in turn; wherein the pit position includes a reference pit position and an actual pit position;

[0074] Dividing the pit positions so that each pit position at least includes a reference pit position and an actual pit position;

[0075] Obtain the reference height Zpj of the chip in the reference pit in a normal state, obtain the detection height corresponding to the chip in the actual pit, and record it as the actual chip height Zp;

[0076] At least the chip presence parameter Zyw is obtained according to the actual chip height Zp and the reference height Zpj, and the chip presence parameter Zyw is compared with a preset threshold to determine the chip status in the actual pit.

[0077] It can be understood that by moving the laser displacement sensor relative to the tray station, the laser displacement sensor can be moved to different tray stations to meet the chip detection at different tray stations. There is no need to set up a separate laser displacement sensor for each tray station, which reduces the detection cost. At the same time, when performing detection, the chip state in the reference pit can be used as a reference reference value, and compared with the actual chip height Zp in the actual pit to obtain the chip presence parameter Zyw; then, according to the comparison relationship between the chip presence parameter Zyw and the preset threshold, the chip state in the actual pit is determined, such as whether there is a chip, or no chip, or two chips are stacked, etc. Compared with the related art that needs to consider the influence of multiple parameters such as distance, angle and flatness, the detection method provided in this embodiment only needs to consider the detection height, is not constrained by other parameters, and is not constrained by chip size, simplifies the detection steps, and makes the overall detection efficiency higher and more versatile.

[0078] It should be noted that the preset thresholds corresponding to different chip states are all different, which are uniformly referred to as preset thresholds here, and then described for different chip states. Among them, the preset threshold is a theoretical value calculated for different chip states based on multiple factors such as chip thickness, pit depth, chip size, and pit size. Considering the influence of factors such as manufacturing errors, it can be a theoretical range. In actual use, chips of different thicknesses correspond to pits of different depths. Therefore, multiple preset thresholds can be calculated based on the differences in chips and pits, and stored in the server. You only need to wait until each detection to retrieve the data; at this time, you can perform information detection on the tray station before detection to obtain the corresponding pit information and chip information, so as to retrieve the corresponding data in time.

[0079] It should also be added that a tray station may include one reference pit position or more than two reference pit positions, depending on actual needs.

[0080] In actual use, the laser displacement sensor can emit point laser to form multiple detection points on the chip or pit to meet the height measurement requirements; of course, the laser displacement sensor can also emit line laser to achieve height measurement in the direction of line scanning.

[0081] In this embodiment, the laser displacement sensor emitting a point laser is taken as an example.

[0082] Exemplarily, moving the laser displacement sensor so that it passes through each pit position on the tray station in sequence includes: installing the laser displacement sensor on a robot arm, so that the laser displacement sensor is driven to move by the movement of the robot arm.

[0083] In an optional embodiment, obtaining a reference height Zpj of a chip in a normal state in a reference pit includes:

[0084] When the laser displacement sensor emits a point laser, the height of the tray station is calibrated;

[0085] Move the laser displacement sensor to the top of the reference pit and emit a point laser to the reference pit to obtain the reference height Zpj.

[0086] It is understandable that the purpose of calibration is to make the height of each pit on the tray station be at the same reference. At this time, the influence of the pit height Zl on chip detection can be eliminated, and it is more convenient to directly use the reference height Zpj in the reference pit and the actual chip height Zp in the actual pit to calculate the chip presence parameter Zyw, thereby improving the detection accuracy. Among them, the reference pit can be a pit that extends separately from the edge of the tray station. At this time, a plate with the same size as the corresponding chip can be placed in the pit to simulate the chip, or the chip can be placed directly. Of course, after the height calibration, the pit corresponding to each chip in the tray station is in a normal state can be used as the reference pit. At this time, the reference pit can be one or more than two. This is only an example, not a specific limitation, and needs to be selected according to the actual situation.

[0087] Please combine Figure 1 and Figure 2 As shown, illustratively, since the laser displacement sensor emits a point laser, multiple detection points are formed on the chip or pit. At this time, as for the reference pit, the laser displacement sensor is moved above the reference pit and a point laser is emitted to the reference pit to obtain the reference height Zpj. This step includes:

[0088] Select n detection points (i.e., reference points) in the reference pit;

[0089] Move the laser displacement sensor to the top of each reference point and emit a point laser to the corresponding reference point to obtain the detection height of each reference point. The reference height Zpj is the average value of the detection heights corresponding to each reference point.

[0090] In this way, the accuracy of the data can be ensured. Among them, each reference point can be a position relatively close to the edge of the chip, such as at each vertex of the chip. Alternatively, the center point of the chip can be selected, and the reference height Zpj can be obtained by at least one measurement; of course, the center point can also be measured multiple times, and the error can be eliminated by calculating the average value. No matter how the measurement is performed, it is sufficient as long as it can truly reflect the reference height Zpj of the chip in the reference pit.

[0091] It should be noted that the chip in the reference pit is in a normal state means that there is one and only one chip in the reference pit, and the chip is just placed in the pit cavity of the reference pit and is not overlapped on the edge of the pit.

[0092] After obtaining the reference height Zpj, the laser displacement sensor can be moved to the top of the actual pit, and a point laser can be emitted to the actual pit to obtain the actual chip height Zp. Among them, the method of obtaining the actual chip height Zp in the actual pit is basically similar to the method of obtaining the reference height Zpj; specifically, multiple points in the actual pit are selected as actual detection points, the laser displacement sensor is moved to pass through each actual detection point respectively, and a point laser is emitted to each actual detection point to obtain the actual detection height corresponding to each actual detection point, and the actual chip height Zp is the average value of each actual detection height. In an alternative embodiment, it is also possible to select the center point in the actual pit as the actual detection point, move the laser displacement sensor to the top of the actual detection point, and emit a laser to obtain the corresponding actual detection height, and the actual detection height is the actual chip height Zp.

[0093] It should be added that, since the chip is generally rectangular, the two diagonals can be used as reference lines, and a point on the diagonal and close to the top corner, or the intersection of the two diagonals can be selected.

[0094] In an optional embodiment, after obtaining the actual chip height Zp, the chip presence parameter Zyw can be calculated in combination with the reference height Zpj. Specifically, the chip presence parameter Zyw=Zp-Zpj, that is, the difference between the reference height Zpj and the actual chip height Zp. At this time, when judging the state of the chip in the actual pit, the chip state that may exist in the actual pit may be a no-material state (i.e., no chip), or a material state (i.e., a chip). Further, when the actual pit is in a material state, the chip can be in a normal state, a warped material state, or a stacked material state. Among them, the warped material state means that part of the chip is in the pit cavity and partly overlaps the edge of the pit; the stacked material state means that although the chip is in the pit cavity, there are at least two chips stacked together.

[0095] Therefore, when the difference between the actual chip height Zp and the reference height Zpj is equal to 0 or approaches 0, it means that the actual pit is in a state with material. When the difference between the actual chip height Zp and the reference height Zpj is large: in the case of a positive number, the actual chip height Zp is greater than the reference height Zpj, and the actual pit may be in a state of no material; in the case of a negative number, the actual chip height Zp is less than the reference height Zpj, and the actual pit may be in a state of stacking material. Because in the state of warping, although there will be a difference between the actual chip height Zp and the reference height Zpj, the difference is not obvious. Therefore, in order to prevent misjudgment, such as Figure 2 As shown, in an optional embodiment, the chip presence parameter Zyw is compared with a preset threshold to determine the chip status in the actual pit, and this step also includes:

[0096] Select m actual detection points in the actual pit, and obtain the actual detection height corresponding to each of the actual detection points;

[0097] Obtain the actual height difference Zm between each actual detection height;

[0098] The chip presence parameter Zyw and the actual height difference Zm are compared with the corresponding preset thresholds to determine the chip status in the actual pit.

[0099] For the convenience of description, the chip presence parameter Zyw corresponds to the chip presence threshold, and the actual height difference value Zm corresponds to the height difference threshold.

[0100] Further, obtaining the actual height difference Zm between each actual detection height includes: obtaining the maximum value and the minimum value of each actual detection height, and the actual height difference Zm is the difference between the maximum value and the minimum value, that is: Zm=Zmax-Zmin. At this time, m is greater than 1, and m is an integer.

[0101] It should be noted in advance that the actual chip height Zp and the reference height Zpj are both calculated based on the straight-line distance between the detection surface and the laser displacement sensor; therefore, the farther the detection surface is from the laser displacement sensor, the greater the corresponding detection height; the closer the detection surface is to the laser displacement sensor, the smaller the corresponding detection height. For example, the reference height is measured when the chip in the reference pit is in a normal state, and the corresponding detection surface is the upper surface of the chip. Therefore, the corresponding detection surface in the actual pit may be the upper surface of the chip or the bottom surface of the actual pit; when the bottom surface of the actual pit is used as the detection surface, the actual chip height Zp corresponding to the actual pit is greater than the reference height Zpj.

[0102] If there is no chip in the actual pit, the actual detection height corresponding to each actual detection point uses the bottom surface of the actual pit as the detection surface. At this time, the actual detection heights are basically the same. Even if there are differences, they are caused by manufacturing errors; therefore, the corresponding actual height difference Zm can be 0, and used as the height difference threshold Za. Of course, it can also be within a certain range considering the error, such as within the range of 0-0.9. It can be understood that the height difference threshold Za can be a numerical value or a range value; when the range value is used as the height difference threshold Za, the specific range can be adjusted according to the actual situation, and only examples are given here. At the same time, the actual chip height Zp corresponding to each actual detection point is greater than the reference height Zpj. At this time, the chip presence parameter Zyw obtained is a positive number and is at least a chip thickness. Considering the error, it can float around the chip thickness accordingly.

[0103] If there is a chip in the actual pit, and the chip is in a normal state, the actual detection heights corresponding to each actual detection point are also basically the same; of course, there will be slight differences caused by manufacturing errors. At this time, the corresponding actual height difference Zm is similar to the above-mentioned case where there is no chip, that is, Zm falls within the above-mentioned range, and it can be considered that Zm matches the height difference threshold Za. At the same time, the actual chip height Zp corresponding to each actual detection point is basically the same as the reference height Zpj. At this time, the chip presence parameter Zyw obtained can be 0, or float around 0; and it is recorded as the material threshold. Among them, the material threshold can be a numerical value or a range value; and, when it is a range value, there is a material critical maximum value Zb and a material critical minimum value Zc, for example, -1.5 to 1.5, at this time Zc = -1.5, Zb = 1.5. This is just an example, and the specific numerical value can be adjusted according to the actual situation.

[0104] If there is a chip in the actual pit and it is in a warped state, the actual detection heights between the actual detection points will be quite different, and the corresponding actual height difference Zm will be larger, resulting in the actual height difference Zm being greater than the height difference threshold Za. At the same time, in the warped state, the detection surface is the upper surface of the chip, but because one edge of the chip overlaps the edge of the pit, the actual chip height Zp corresponding to each actual detection point may be less than the reference height Zpj. At this time, the chip presence parameter Zyw obtained is a negative number. However, at this time, the difference between the actual chip height Zp and the reference height Zpj is small. It is preferred to compare and judge the actual height difference Zm with the height difference threshold.

[0105] If there is a chip in the actual pit and it is in a stacking state, and the detection surface is the upper surface of the chip, then the actual height difference Zm can be similar to the above chip in a normal state, the difference is that the actual detection heights are different; at this time, the actual height difference Zm actually matches the height threshold. However, the actual chip height Zp corresponding to each actual detection height is less than the reference height Zpj, and the chip presence parameter Zyw obtained at this time is negative, and at least a negative chip thickness.

[0106] In summary, if Figure 2 As shown, the chip presence parameter Zyw and the actual height difference Zm are compared with the corresponding preset thresholds to determine the chip status in the actual pit. This step also includes:

[0107] Compare the actual height difference Zm with the height difference threshold;

[0108] When the actual height difference value Zm matches the height difference threshold Za, the chip presence parameter Zyw is compared with the material threshold; when the chip presence parameter Zyw is greater than the material threshold, the actual pit is in a no-material state; when the chip presence parameter Zyw is less than the material threshold, the actual pit is in a stacked material state; when the chip presence parameter Zyw matches the material threshold, the actual pit is in a normal state;

[0109] When the actual height difference value Zm does not match the height difference threshold Za, the actual pit is in a warped state.

[0110] It should be noted that when the material threshold is a range value, when the actual height difference value Zm matches the height difference threshold Za: if the chip presence parameter Zyw is greater than Zb (for example, 1.5), it is in a no-material state; if the chip presence parameter Zyw is less than Zc (for example, -1.5), it is in a stacked material state.

[0111] In actual use, before performing the step of comparing the actual height difference value Zm with the height difference threshold, it is necessary to obtain the height difference threshold and the material threshold.

[0112] In an alternative embodiment, if the detection height is calculated based on the plane where the carrier plate is placed, the straight-line distance detected by the laser displacement sensor needs to be converted, that is, the detection height is the straight-line distance between the plane where the carrier plate is placed and the detection surface. Therefore, the farther the detection surface is from the laser displacement sensor, the smaller the corresponding detection height; the closer the detection surface is to the laser displacement sensor, the larger the corresponding detection height. The detection surface is the surface that receives the laser emitted by the laser displacement sensor.

[0113] If there is no chip in the actual pit, the corresponding actual height difference Zm is 0, and is used as the height difference threshold Za (of course, it can also be a range value). At the same time, the actual chip height Zp corresponding to the actual pit is less than the reference height Zpj. At this time, the chip presence parameter Zyw obtained is a negative number, and is at least a negative chip thickness. Considering the error, it can float around the chip thickness accordingly.

[0114] If there is a chip in the actual pit and the chip is in a normal state, the corresponding actual height difference Zm is similar to the above case where there is no chip. At the same time, the corresponding actual chip height Zp is basically the same as the reference height Zpj. At this time, the chip presence parameter Zyw obtained can be 0, or float around 0; and it is recorded as the material threshold. When it is a range value, there is a material critical maximum value Zb and a material critical minimum value Zc, for example, -1.5 to 1.5, at this time Zc = -1.5, Zb = 1.5. This is just an example, and the specific values ​​can be adjusted according to the actual situation.

[0115] If there is a chip in the actual pit and it is in a warped state, the corresponding actual height difference Zm is large and greater than the height difference threshold Za. At the same time, the difference between the corresponding actual chip height Zp and the reference height Zpj is small. At this time, it is preferred to compare and judge the actual height difference Zm with the height difference threshold Za.

[0116] If there is a chip in the actual pit and it is in the stacking state, the corresponding actual height difference Zm is similar to the normal state of the above chip. At the same time, the corresponding actual chip height Zp is greater than the reference height Zpj. At this time, the chip presence parameter Zyw is a positive number and is at least one chip thickness.

[0117] Based on this, the chip presence parameter Zyw and the actual height difference Zm are compared with the corresponding preset thresholds to determine the chip status in the actual pit. This step also includes:

[0118] Compare the actual height difference Zm with the height difference threshold Za;

[0119] When the actual height difference value Zm matches the height difference threshold, the chip presence parameter Zyw is compared with the material threshold; when the chip presence parameter Zyw is greater than the material threshold, the actual pit is in a stacked state; when the chip presence parameter Zyw is less than the material threshold, the actual pit is in a no-material state; when the chip presence parameter Zyw matches the material threshold, the actual pit is in a normal state;

[0120] When the actual height difference value Zm does not match the height difference threshold Za, the actual pit is in a warped state.

[0121] It should be noted that when the material threshold is a range value, when the actual height difference value Zm matches the height difference threshold: if the chip presence parameter Zyw is greater than Zb (for example, 1.5), it is in a stacking state; if the chip presence parameter Zyw is less than Zc (for example, -1.5), it is in a no-material state.

[0122] Embodiment 2

[0123] like Figure 3 and Figure 4 As shown, a detection method is provided in this embodiment, which is different from the first embodiment in that, in this embodiment, the chip height Zic of a single chip and the pit height Zl of a pit can be obtained, and the chip presence parameter Zyw can be obtained based on the actual chip height Zp, the chip height Zic and the pit height Zl. At this time, there is no need to divide the pits in the tray station, and they can all be identified as actual pits.

[0124] Exemplarily, obtaining the chip presence parameter Zyw according to the actual chip height Zp, the chip height Zic and the pit height Zl includes: chip presence parameter Zyw=100%×|Zp-Zl| / Zic.

[0125] Among them, when the chip is placed in the pit, the actual chip height Zp is the average value of the actual detection height corresponding to multiple actual detection points, and the pit height Zl and the single chip height Zic are determined. It should be noted that the pit height Zl mentioned here is the detection height corresponding to the laser displacement sensor emitting the laser to the bottom surface of the pit when there is no chip in the pit. Because for different chip states, the corresponding actual chip height Zp is also different. For example, when there is no material, the actual chip height Zp may be equal to the pit height Zl, and when there is material, the actual chip height Zp will be less than the pit height Zl. Therefore, the absolute value of the difference between the actual chip height Zp and the pit height Zl can be calculated to determine the chip state in each actual pit. At the same time, the chip height Zic mentioned here is the thickness of the chip itself. This data is known and can be stored in the server. In addition, the corresponding pit height Zl can also be stored in the server, and then the height of the tray station is calibrated before each detection so that the pit height Zl reaches the preset value. Alternatively, the pit height Zl can be re-obtained before each detection; at this time, since the pit depth is known, it is only necessary to obtain the distance between the tray station and the laser displacement sensor, and the sum of the two is the pit height Zl.

[0126] It should be noted that the method of obtaining the actual chip height Zp is similar to that in the first embodiment, so it will not be described in detail.

[0127] The following is an explanation of the different chip states.

[0128] If there is no chip in the actual pit, the corresponding actual chip height Zp is basically the same as the pit height Zl. At this time, the calculated chip presence parameter Zyw may be 0. Considering the influence of errors, it can be slightly expanded, for example, with 5% as the maximum value. If it is less than or equal to 5%, it means that the actual pit is in a no-material state. At this time, 5% can be used as the no-material threshold. This is just an example, and the specific value can be adjusted according to the actual situation.

[0129] If there is a chip in the actual pit and the chip is in normal state, the corresponding actual chip height Zp is less than the pit height Zl, so the difference between the two is basically the same as the chip height Zic, or slightly less than the chip height Zic, or slightly greater than the chip height Zic. At this time, the calculated chip presence parameter Zyw can fluctuate around 100%, for example, between 95%-105%, and this range is used as the material threshold. This is only an example, and the specific value can be adjusted according to the actual situation.

[0130] If there is a chip in the actual pit and the chip is in a warped state, the corresponding actual chip height Zp is smaller than the pit height Zl, and the difference between the two is greater than the chip height Zic; at the same time, the difference between the actual chip height Zp and the single chip height Zic is small.

[0131] If there is a chip in the actual pit, and the chip is in a stacking state, the corresponding actual chip height Zp is less than the pit height Zl, and the difference between the two is greater than the chip height Zic. Among them, taking the overlap of two materials as an example, the difference between the actual chip height Zp and the pit height Zl can be twice the chip height Zic, and the corresponding calculated chip presence parameter Zyw can be 200%. Considering the influence of errors, it can be slightly expanded to a range value, for example, between 195%-205%, and this range is used as the stacking threshold. This is just an example, and the specific value can be adjusted according to the actual situation.

[0132] Furthermore, since the difference between the actual chip height Zp and the single chip height Zic is small in the warped state, the calculated chip presence parameter Zyw may fall within the material threshold. At this time, in order to reduce the judgment error, it is necessary to consider the maximum and minimum values ​​of each actual detection height corresponding to the actual pit. Therefore, when judging the chip state in the actual pit, it is also necessary to obtain the warp parameter Zh=Zm / Zic based on the actual height difference Zm and the chip height Zic. Among them, as mentioned in Example 1, in the no-material state, normal state and stacked state, the actual height difference Zm is basically 0. From the perspective of error influence, the maximum value corresponding to the actual height difference Zm can be 0.5, or it can be slightly expanded to 0.9, that is, the height difference threshold Za corresponding to the actual height difference Zm. This is only an example, and the specific value can be adjusted according to the actual situation. Therefore, the ratio obtained by comparing the height difference threshold Za with the chip height Zic can be used as the warping threshold of the warping parameter Zh. Therefore, the warping parameter Zh can be floated with 0 as the reference, and the specific adjustment range is based on the actual situation. Therefore, when the chip is in the warping state, the corresponding actual height difference Zm is bound to be greater than the height difference threshold, and then the corresponding warping parameter Zh is greater than the warping threshold.

[0133] Therefore, in order to improve the accuracy of judgment, the chip presence parameter Zyw and the warping parameter Zh can be compared together to determine whether the chip in the actual pit is in a warping state.

[0134] In summary, if Figure 4 As shown, comparing the chip presence parameter Zyw with a preset threshold to determine the chip status in the actual pit position includes:

[0135] Compare the warping parameter Zh with the warping threshold;

[0136] When the material warping parameter Zh matches the material warping threshold, the chip presence / absence parameter Zyw is compared with the no-material threshold, the material presence threshold and the stacking threshold respectively; wherein, when the chip presence / absence parameter Zyw matches the no-material threshold, the actual pit is in a no-material state; when the chip presence / absence parameter Zyw matches the material presence threshold, the actual pit is in a normal state; when the chip presence / absence parameter Zyw matches the stacking threshold, the actual pit is in a stacking state;

[0137] When the warping parameter Zh does not match the warping threshold, the actual pit is in a warping state.

[0138] Furthermore, before comparing the warping parameter Zh with the warping threshold step, it is necessary to obtain the warping threshold, the no-material threshold, the material threshold, and the stacking threshold. At this time, the preset thresholds include the warping threshold, the no-material threshold, the material threshold, and the stacking threshold. Among them, similar to the first embodiment, each threshold is a theoretical value calculated for different chip states based on multiple factors such as chip thickness, pit depth, chip size, and pit size. Considering the influence of factors such as manufacturing errors, it can be a theoretical range; and each threshold can be stored in the server.

[0139] It should be noted that in Example 2, the height of the tray station also needs to be calibrated to ensure that the detection benchmarks of each pit in the tray station are unified.

[0140] Embodiment 3

[0141] In this embodiment, the laser displacement sensor uses a line laser to scan the tray station for height detection. At this time, it is necessary to adjust the parallelism between the line laser and the edge of the tray station to reduce the detection error. During the detection process, the laser displacement sensor is moved from one of the vertex corners of the tray station until the laser displacement sensor passes through all the pits on the tray station. Of course, it does not necessarily have to be one of the vertex corners, and the starting point of the movement of the laser displacement sensor can be determined based on the actual detection range. In actual use, if the width of the line laser emitted by the laser displacement sensor is greater than the width of each pit, then there are multiple line lasers scanning each pit.

[0142] Since the shape of the chip is generally rectangular, the pits are set in a rectangular shape. At this time, the two diagonals in the pit can be used as a reference, and four points on the two diagonals that form a rectangle can be selected as detection points. Among them, the area of ​​the rectangle surrounded by the four points accounts for 50%-90% of the area of ​​the rectangle surrounded by the pit edge line. This is only an example, and the specific numerical range can be adjusted according to actual needs. Such a setting ensures that the four detection points are not too close or too far apart. If the four detection points are too close, the difference in detection heights corresponding to the four detection points is not obvious enough, which affects the detection results; if the four detection points are too scattered, the detection points may be offset or inaccurate, which will also affect the detection structure.

[0143] For example, after obtaining the chip height Zic of a single chip and the pit height Zl of a pit, the chip presence parameter Zyw=100%×|Zp-Zl| / Zic can be obtained based on the actual chip height Zp, chip height Zic and pit height Zl, where the chip height Zic and pit height Zl are both known data.

[0144] It should be noted that, in this embodiment, each pit located on the tray station can be an actual pit. At the same time, when obtaining the actual chip height Zp, the detection height corresponding to all points in the scanning range corresponding to the actual pit can be obtained after the line laser line scan, and the actual chip height Zp is the average value of each detection height. Furthermore, it can be that the four points enclosed in the rectangle are first determined, and multiple points are taken within the range enclosed by the four points to calculate the average value; or, the average value of the four points is directly taken.

[0145] like Figure 5 As shown, in actual use, it is also necessary to obtain the height set Z corresponding to the actual detection height at different positions in the actual pit, and combine the actual chip height Zp and the height set Z to obtain the height offset ratio Zz=100%×|Z-Zp| / Z. Among them, the height set Z is a finite set.

[0146] If there is no chip in the actual pit, the corresponding actual chip height Zp is basically the same as the pit height Zl, and the chip presence parameter Zyw calculated at this time is similar to that in Example 2. In addition, when there is no chip, the bottom surface of the pit is used as the detection reference for detection, so the difference between the various values ​​in the height set Z is small, and the difference with the actual chip height Zp is also small, or even basically the same. Therefore, the obtained height offset ratio Zz may be between 0-5%, which is only used as an example here. Among them, this range can be used as an offset threshold. When the offset threshold is a theoretical value, it can be 5%; when the offset threshold is a theoretical range, it can be 0-5%. However, at this time, it has been determined that the chip presence parameter Zyw is within the corresponding material-free threshold, so there is no need to consider the height offset ratio Zz.

[0147] If there is a chip in the actual pit, and the chip is in a normal state, the corresponding actual chip height Zp is less than the pit height Zl, and the difference between the two is basically the same as the chip height Zic; specifically, it is similar to Example 2. At this time, it can be obtained that the chip presence parameter Zyw fluctuates around 100%, for example, between 95%-105%, which is only used as an example here. At the same time, since the upper surface of the chip is used as the detection reference at this time, the difference between the various values ​​in the height set Z is small, and the difference with the actual chip height Zp is also small, or even basically the same; therefore, the obtained height offset ratio Zz may be between 0-5%, which is only used as an example here.

[0148] If there is a chip in the actual pit and the chip is in a warped state, the corresponding actual chip height Zp is less than the pit height Zl, and the difference between the two is greater than the chip height Zic, but the difference is small. At the same time, since the chip is in a warped state, the upper surface of the chip is not horizontal, so the difference between the values ​​in the height set Z obtained at this time is obvious, and each value also has a significant difference with the actual chip height Zp. Therefore, the height offset ratio Zz obtained at this time is bound to be greater than the above offset threshold.

[0149] If there is a chip in the actual pit and the chip is in a stacking state, the corresponding actual chip height Zp is less than the pit height Zl, and the difference between the two is greater than the chip height Zic. Specifically, it is similar to the judgment method in Example 2. At the same time, in the stacking state, the upper surface of the topmost chip is still used as the detection reference, so the difference between the various values ​​in the height set Z is small at this time, and the difference with the actual chip height Zp is also small, or even basically the same, and the obtained height offset ratio Zz is less than or equal to the height offset threshold. It should be added that at this time, it has been determined whether the chip parameter Zyw is within the corresponding stacking threshold, so there is no need to consider the height offset ratio Zz.

[0150] In summary, if Figure 5 As shown, illustratively, the chip presence parameter Zyw and the actual height difference Zm are compared with the corresponding preset thresholds to determine the chip status in the actual pit. This step also includes:

[0151] Compare the height offset ratio Zz with the offset threshold;

[0152] When the height offset ratio Zz matches the offset threshold, the chip presence / absence parameter Zyw is compared with the no-material threshold, the material threshold and the stacking threshold respectively; whereby, when the chip presence / absence parameter Zyw matches the no-material threshold, the actual pit is in a no-material state; when the chip presence / absence parameter Zyw matches the material threshold, the actual pit is in a normal state; when the chip presence / absence parameter Zyw matches the stacking threshold, the actual pit is in a stacking state;

[0153] When the height offset ratio Zz does not match the offset threshold, the actual pit is in a warped state.

[0154] Furthermore, before comparing the height offset ratio Zz with the offset threshold step, it is necessary to obtain the offset threshold, the no-material threshold, the material threshold, and the stacking threshold. At this time, the preset thresholds include the offset threshold, the no-material threshold, the material threshold, and the stacking threshold. Among them, similar to the first embodiment, each threshold is a theoretical value calculated for different chip states based on multiple factors such as chip thickness, pit depth, chip size, and pit size. Considering the influence of factors such as manufacturing errors, it can be a theoretical range; and each threshold can be stored in the server.

[0155] It should be noted that, in this embodiment, it is not necessary to calibrate the tray station, and it is only necessary to determine the pit height Z1 before detection. Of course, the tray station can also be calibrated before detection so that it is within the determined height range. The specific operation situation is selected according to actual needs.

[0156] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0157] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the scope of patent protection of the present application shall be subject to the attached claims.

Claims

1. A detection method, characterized in that: The detection method comprises the following steps: Move the laser displacement sensor so that it passes through each pit position on the tray station in turn; Obtain a reference height Zpj of a chip in a reference pit in a normal state, or obtain a chip height Zic of a single chip and a pit height Zl of the pit; Get the detection height corresponding to the chip in the actual pit and record it as the actual chip height Zp; Obtaining a chip presence parameter Zyw according to the actual chip height Zp and the reference height Zpj, or obtaining a chip presence parameter Zyw according to the actual chip height Zp, the chip height Zic and the pit height Zl; The chip presence parameter Zyw is compared with a preset threshold to determine the chip status in the actual pit.

2. The detection method according to claim 1, characterized in that: The step of obtaining a reference height Zpj of a chip in a normal state in a reference pit includes: When the laser displacement sensor emits a point laser, the height of the tray station is calibrated; Select n reference points in the reference pit; Move the laser displacement sensor to above each of the reference points, and emit a point laser to the corresponding reference point to obtain the detection height of each of the reference points. The reference height Zpj is the average value of the detection heights corresponding to each of the reference points.

3. The detection method according to claim 2, characterized in that: The obtaining of the chip presence parameter Zyw according to the actual chip height Zp and the reference height Zpj comprises: The chip has a parameter Zyw=Zp-Zpj.

4. The detection method according to claim 3, characterized in that: The comparing the chip presence parameter Zyw with a preset threshold to determine the chip status in the actual pit position includes: Select m actual detection points in the actual pit position, and obtain the actual detection height corresponding to each of the actual detection points; Obtaining an actual height difference Zm between each of the actual detection heights; The chip presence parameter Zyw and the actual height difference value Zm are respectively compared with the corresponding preset thresholds to determine the chip status in the actual pit; wherein the preset thresholds include a material presence threshold and a height difference threshold.

5. The detection method according to claim 4, characterized in that: The detection height is the straight-line distance between the laser displacement sensor and the detection surface; the chip state includes a no-material state, a material state, a stacked-material state, and a warped-material state; The step of comparing the chip presence parameter Zyw and the actual height difference value Zm with the corresponding preset thresholds to determine the chip status in the actual pit includes: Comparing the actual height difference value Zm with the height difference threshold; When the actual height difference value Zm matches the height difference threshold, the chip presence parameter Zyw is compared with the material threshold; wherein, when the chip presence parameter Zyw is greater than the material threshold, the actual pit is in the no-material state; when the chip presence parameter Zyw is less than the material threshold, the actual pit is in the stacked material state; when the chip presence parameter Zyw matches the material threshold, the actual pit is in the normal state; When the actual height difference value Zm does not match the height difference threshold, the actual pit position is in the warping state.

6. The detection method according to claim 4, characterized in that: The detection height is the straight-line distance between the plane on which the carrier plate is placed and the detection surface; the chip status includes a no-material state, a material state, a stacked material state, and a warped material state; The step of comparing the chip presence parameter Zyw and the actual height difference Zm with the corresponding preset thresholds to determine the chip status in the actual pit position also includes: Comparing the actual height difference value Zm with the height difference threshold; When the actual height difference value Zm matches the height difference threshold, the chip presence parameter Zyw is compared with the material threshold; wherein, when the chip presence parameter Zyw is greater than the material threshold, the actual pit is in the stacking state; when the chip presence parameter Zyw is less than the material threshold, the actual pit is in the no-material state; when the chip presence parameter Zyw matches the material threshold, the actual pit is in the normal state; When the actual height difference value Zm does not match the height difference threshold, the actual pit position is in the warping state.

7. The detection method according to claim 1, characterized in that: The chip presence parameter Zyw obtained according to the actual chip height Zp, chip height Zic and pit height Zl includes: The chip has a parameter Zyw=100%×|Zp-Zl| / Zic.

8. The detection method according to claim 7, characterized in that: The comparing the chip presence parameter Zyw with a preset threshold to determine the chip status in the actual pit position includes: Select m actual detection points in the actual pit position, and obtain the actual detection height corresponding to each of the actual detection points; Obtaining an actual height difference Zm between each of the actual detection heights; According to the actual height difference Zm and the chip height Zic, a warpage parameter Zh=Zm / Zic is obtained.

9. The detection method according to claim 8, characterized in that: The preset thresholds include a material warping threshold, a material-free threshold, a material-existing threshold, and a material stacking threshold; the chip status includes a material-free status, a normal status, a material stacking status, and a material warping status; The step of comparing the chip presence parameter Zyw with a preset threshold to determine the chip status in the actual pit also includes: Comparing the warping parameter Zh with the warping threshold; When the material warping parameter Zh matches the material warping threshold, the chip presence / absence parameter Zyw is compared with the no-material threshold, the material presence threshold and the stacking threshold respectively; wherein, when the chip presence / absence parameter Zyw matches the no-material threshold, the actual pit position is in the no-material state; when the chip presence / absence parameter Zyw matches the material presence threshold, the actual pit position is in the normal state; when the chip presence / absence parameter Zyw matches the stacking threshold, the actual pit position is in the stacking state; When the material warping parameter Zh does not match the material warping threshold, the actual pit position is in the material warping state.

10. The detection method according to claim 4 or 8, characterized in that: The obtaining of the actual height difference Zm between the actual detected heights comprises: The maximum value Zmax and the minimum value Zmin of each of the actual detected heights are obtained, and then the actual height difference Zm=Zmax-Zmin; wherein m is greater than 1.

11. The detection method according to claim 7, characterized in that: The comparing the chip presence parameter Zyw with a preset threshold to determine the chip status in the actual pit position includes: Obtain a height set Z corresponding to actual detection heights at different positions in the actual pit; Combining the actual chip height Zp and the height set Z, the height offset ratio Zz is obtained: Wherein, Zz=100%×|Z-Zp| / Z.

12. The detection method according to claim 11, characterized in that: The preset thresholds include an offset threshold, a no-material threshold, a material threshold, and a stacking threshold; the chip status includes a no-material status, a normal status, a stacking status, and a warping status; The step of comparing the chip presence parameter Zyw with a preset threshold to determine the chip status in the actual pit also includes: Comparing the height offset ratio Zz with the offset threshold; When the height offset ratio Zz matches the offset threshold, the chip presence / absence parameter Zyw is compared with the no-material threshold, the material presence threshold and the stacking threshold respectively; wherein, when the chip presence / absence parameter Zyw matches the no-material threshold, the actual pit position is in the no-material state; when the chip presence / absence parameter Zyw matches the material presence threshold, the actual pit position is in the normal state; when the chip presence / absence parameter Zyw matches the stacking threshold, the actual pit position is in the stacking state; When the height offset ratio Zz does not match the offset threshold, the actual pit position is in the warping state.

13. The detection method according to claim 1, characterized in that: The method of obtaining the detection height corresponding to the chip in the actual pit and recording it as the actual chip height Zp includes: When the laser displacement sensor emits a point laser, the center point of the actual pit is selected as the actual detection point, the laser displacement sensor is moved above the actual detection point, and the point laser is emitted to obtain the actual detection height, and the actual detection height is the actual chip height Zp; or, When the laser displacement sensor emits point laser, multiple actual detection points in the actual pit are selected, the laser displacement sensor is moved to pass through each of the actual detection points respectively, and point laser is emitted to each of the actual detection points to obtain the actual detection height corresponding to each of the actual detection points. The actual chip height Zp is the average value of each of the actual detection heights.

14. The detection method according to claim 1, characterized in that: The step of obtaining the detection height corresponding to the chip in the actual pit and recording it as the actual chip height Zp also includes: When the laser displacement sensor emits a line laser, the detection heights corresponding to multiple points in the scanning range corresponding to the actual pit position after the line laser line scan are obtained, and the actual chip height Zp is the average value of each of the detection heights.

Images