An optical center offset calibration fixture and calibration adjustment method

Abstract

The invention discloses an optical center offset calibration fixture and a calibration adjustment method. Among them, the calibration fixture includes a marker plate pressing plate. A marker plate and a column are respectively and fixedly arranged on the same side of one surface of the marker plate pressing plate, or a marker plate and a column are respectively and fixedly arranged on two opposite and different side surfaces of the marker plate pressing plate. The column is perpendicular to the marker plate pressing plate. A marking line is arranged at the center position of one surface of the marker plate, and the marking line is arranged in the same direction as the column. When calibrating with this calibration fixture, even if the height of the marker plate changes, the marking line is always within the field of view of the camera, and multiple coordinate changes can be obtained simply and quickly. At the same time, combined with the offset at a certain height, the offset of the optical center relative to the splitting knife at any height within the working height range can be obtained by fitting.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor packaging and testing equipment, and particularly to a calibration fixture for the offset of the optical center relative to the center of the bonding tool and an optical calibration adjustment method. Background Art

[0002] For products with solder joints at different heights, the current method for calibrating the offset of the optical center relative to the center of the bonding tool is as follows: at a certain height, use the bonding tool to print marks on the material, and then move the optical center to the position where it coincides with the center of the marks for calibration to obtain the offsets in the X and Y directions of the current height plane. The offsets at other heights are defaulted to be the same. Due to mechanical assembly errors, both the optical center and the rotation plane of the bonding head are not perpendicular to the horizontal plane. Therefore, the existing method will cause deviations in the offsets at other heights compared to the offset at the calibration height. Another method is to print marks with the bonding tool at different heights. This method requires multiple mark printing and centering, and is time-consuming and inconvenient to use. Summary of the Invention

[0003] In view of the above problems, the problems to be solved by the present invention are to provide a calibration fixture for the offset of the optical center relative to the center of the bonding tool and an optical calibration adjustment method that can achieve convenient fine-tuning at different heights.

[0004] The first technical solution of the present invention is as follows:

[0005] A calibration fixture for the offset of the optical center relative to the center of the bonding tool includes a marker plate pressing plate. On the same side of one surface of the marker plate pressing plate, a marker plate and a column are respectively and fixedly arranged; the column is perpendicular to the marker plate pressing plate; a marking line is provided at the center position of one surface of the marker plate, and the marking line is arranged in the same direction as the column; alternatively, the calibration fixture includes a marker plate pressing plate. On the two opposite and different side surfaces of the marker plate pressing plate, a marker plate and a column are respectively and fixedly arranged, and a middle through hole is arranged at the center-symmetric position of the marker plate pressing plate; the column is perpendicular to the marker plate pressing plate; a marking line is provided at the center position of one surface of the marker plate, and the marking line is arranged in the same direction as the column.

[0006] In an embodiment, in the calibration fixture, a marker plate sliding plate and an elastic pressing member are included;

[0007] The marker plate sliding plate is plate-shaped and has a longitudinal section in a "concave" shape, including a bottom plate and two side plates; a downward concave sliding groove is formed on the upper surface of the bottom plate in the direction of the two side plates;

[0008] The elastic pressing member is adapted to be snapped into the sliding groove of the marking plate slide and can move relative to the marking plate slide; the marking plate is fixedly arranged on the elastic pressing member, and the marking line of the marking plate is arranged away from the sliding groove; both ends of the marking plate pressing plate are fixedly arranged between the two side plates of the marking plate slide, and the lower surface of the marking plate pressing plate is adapted to be in fitting contact with the marking line of the marking plate, and the marking line can be observed through the through hole arranged at the central symmetry position of the marking plate pressing plate.

[0009] In one embodiment, the calibration fixture further includes a fine adjustment screw rod; correspondingly, a threaded through hole is arranged on one of the side plates of the marking plate slide plate; the fine adjustment screw rod is adapted to be screwed into the threaded through hole and is in fitting contact with the elastic pressing member, and the fine adjustment screw rod can push the elastic pressing member to move relative to the marking plate slide.

[0010] In one embodiment, in the calibration fixture, through holes are formed in the bottom plate of the marking plate slide in opposite directions of the two side plates, and the through holes and the sliding groove are in a stepped structure.

[0011] In one embodiment, in the calibration fixture, inner grooves are formed in the inner walls of the two side plates of the marking plate slide, and both ends of the marking plate pressing plate are respectively adapted to be snapped into the two inner grooves and form a tight contact.

[0012] In one embodiment, in the calibration fixture, the elastic pressing member is a pressing spring piece with a longitudinal section in the shape of the letter "W", and an inner concave cavity is formed in the middle of the pressing spring piece, and the marking plate is adapted to be fixedly arranged in the inner concave cavity of the pressing spring piece.

[0013] In one embodiment, in the calibration fixture, a central through hole is formed in the inner concave cavity.

[0014] In one embodiment, in the calibration fixture, the elastic pressing member is a regular body, and the marking plate is fixedly arranged at the middle position of the regular body.

[0015] In one embodiment, in the calibration fixture, the marking line is a cross, a circle, a triangle or other regular bodies.

[0016] The present invention also provides an optical calibration adjustment method for the above calibration fixture, including the following steps:

[0017] Install the calibration fixture on the bonder head, adjust the rotation of the elastic pressing member and the marking plate pressing plate, so that the center of the marking line of the marking plate is close to the optical center of the camera lens, the marking line is imaged in the camera, and the coordinates (x0, y0) of the center of the marking line in the image are identified through image processing; where x0 is the X-direction coordinate and y0 is the Y-direction coordinate;

[0018] Automatically adjust the height of the bonding head at certain height intervals, and record the X-direction and Y-direction coordinates of the center of the marking line corresponding to each height Hn of the bonding head in the image, which are (xn, Hn) and (yn, Hn) respectively; according to the recorded data, fit the X-direction and Y-direction coordinates of the center of the marking line corresponding to any height H within the working height range in the image, which are (x, H) and (y, H) respectively, and store them in the system database;

[0019] Remove the calibration jig, replace it with a bonding tool, and record the current mounting base coordinates (X0, Y0); the bonding head prints marks on the material, and the height of the bonding head for printing marks is H1; move the mounting base to make the optical center cursor coincide with the center of the mark, and record the mounting base coordinates (X1, Y1), and obtain the offsets of the optical center relative to the bonding tool in the X-direction and Y-direction when the bonding head height is H1, which are (X1 - X0, H1) and (Y1 - Y0, H1). When the bonding head height is H1, the X-direction and Y-direction coordinates of the center of the marking line obtained by fitting in the image are (x1, H1) and (y1, H1) respectively;

[0020] The optical pixel equivalent is denoted as a, and the offsets of the optical center of the bonding head relative to the bonding tool in the X-direction and Y-direction at any height H are (X1 - X0 + ax - ax1, H) and (Y1 - Y0 + ay - ay1, H) respectively, realizing optical calibration adjustment.

[0021] If the bonding tool is replaced again, calibration needs to be performed again; at this time, it is necessary to record the current mounting base coordinates (X3, Y3), print marks on the material, record the height H2 of the marks, move the mounting base until the optical center coincides with the center of the marks, and record the coordinates (X4, Y4), and obtain the offsets at the current height H2, which are (X4 - X3, H2) and (Y4 - Y3, H2). When the bonding head height is H2, the X-direction and Y-direction coordinates of the center of the marking line obtained by fitting in the image are (x2, H2) and (y2, H2) respectively. At any height within the working range of the bonding head, the new X-offset is (X4 - X3 + ax - ax2, H), and the new Y-offset is (Y4 - Y3 + ay - ay2, H).

[0022] Compared with the prior art, the calibration jig provided by the present invention has the following advantages:

[0023] 1. When calibrating this calibration jig, by installing the calibration jig on the bonding head, even if the height of the marking plate changes, the marking line is always within the field of view of the camera, realizing the function of the image software to automatically and continuously identify the coordinates at different heights, and multiple coordinate changes can be obtained simply and quickly; at the same time, by recording the product of the coordinate difference and the pixel equivalent and combining the offset at a certain height, the offset between the optical center and the bonding tool at any height within the working height range can be fitted;

[0024] 2. The elastic force of the elastic pressing member can realize fine adjustment of the position of the marking plate, reducing the adjustment time for centering the marking line and the visual field center; the way the elastic pressing member presses the marking plate can make the adjustment of the marking plate convenient and fast.

[0025] 3. Each time the bonding tool is replaced, a printing mark calibration can be performed again, and a new offset can be calculated based on the new calibration value, reducing the offset error caused by the height error of the bonding tool.

[0026] 4. By sliding the marking plate and rotating the marking plate pressing plate, the marking line can always be near the optical center, which can reduce the error caused by distortion.

[0027] 5. By screwing in or out the fine adjustment screw, the fine adjustment of the position of the marking plate can be realized, making the sliding of the marking plate smoother and the adjustment accuracy higher, and further reducing the adjustment time for centering the marking line center and the visual field center. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1a 、 1b are respectively schematic structural diagrams of two configurations of the calibration fixture of the present invention;

[0029] Figure 2a 、 2b is respectively a schematic total assembly structural diagram of the calibration fixture for the offset of the optical center relative to the bonding tool center in an embodiment;

[0030] Figure 3a 、 3b are respectively schematic structural diagrams of the marking plate slide plate in the total assembly of the calibration fixture;

[0031] Figure 4 is a schematic structural diagram of the marking plate pressing plate in the total assembly of the calibration fixture;

[0032] Figure 5 is a schematic structural diagram of the marking plate in the total assembly of the calibration fixture;

[0033] Figure 6 is a schematic structural diagram of the compression spring piece in the total assembly of the calibration fixture;

[0034] Figure 7 is a schematic structural diagram of the bonding tool and the bonder head installation;

[0035] Figure 8 is a schematic structural diagram of the lens installation;

[0036] Figure 9 is a schematic structural diagram of the offset installation of the lens and the bonding tool;

[0037] Figure 10 is a schematic structural diagram of the optical detection installation in the total assembly of the calibration fixture;

[0038] Figure 11It is a top view of the positional relationship between the lens and the bonding tool tip.

[0039] Figure 12 It is a schematic diagram of the rotational movement structure of the bonding head relative to the X-axis.

[0040] Figure 13 It is a process flow diagram of two optical calibration adjustments for the calibration jig. Specific embodiments

[0041] Next, in conjunction with the accompanying drawings, a more detailed description of the preferred embodiments of the present invention will be given.

[0042] As Figure 1a shown, an optical center offset calibration jig 100 provided by the present invention includes a marker plate pressing plate 5. On the same side of one surface of the marker plate pressing plate 5, a marker plate 8 and a column 52 are fixedly provided respectively; the column 52 is perpendicular to the marker plate pressing plate 5; at the center position of one surface of the marker plate 8, a marking line 82 is provided, and the marking line 82 is arranged in the same direction as the column 52, that is, the marking line 82 is arranged facing away from the marker plate pressing plate 5.

[0043] As Figure 1b shown, the present invention also provides another structure of an optical center offset calibration jig 100, which includes a marker plate pressing plate 5. On the two opposite and different sides of the marker plate pressing plate 5, a marker plate 8 and a column 52 are fixedly provided respectively, and the marker plate 8 is perpendicular to the column 52. A central through hole 51 is provided at the central symmetry position of the marker plate pressing plate 5; the column 52 is perpendicular to the marker plate pressing plate 5; at the center position of one surface of the marker plate 8, a marking line 82 is provided, and the marking line 82 is arranged in the same direction as the column 52, and the marking line 82 can be observed through the central through hole 51 of the marker plate pressing plate 5.

[0044] In the above calibration jig 100, specifically, the marker plate pressing plate 5 is a rectangular plate structure, and the column 52 is a cylindrical structure; the central axis a of the marker plate pressing plate 5 intersects and is perpendicular to the central axis of the column 52. The marker plate 8 is a cubic block structure; the marking line 81 can be a cross, a circle, a triangle or other regular shapes.

[0045] As Figure 2a and 2b shown, an optical center offset calibration jig 100 provided in an embodiment of the present invention includes a marker plate slide 6, a marker plate pressing plate 5, a marker plate 8, an elastic pressing member 9 and a fine adjustment screw rod 7.

[0046] As Figure 3a and 3bAs shown, the marking plate slide plate 6 is a long plate-like structure, and the longitudinal section is a "concave" structure, including a bottom plate 62 and two side plates 61; a concave slide groove 621 is provided on the upper surface of the bottom plate 62 along the length direction, and one of the side plates 61 is provided with a threaded through hole 612. Specifically, the marking plate slide plate 6 can be made of a hard material such as stainless steel, aluminum alloy or engineering plastics, and the marking plate slide plate 6 can be a stainless steel or aluminum alloy rectangular block that is cut and the middle part is dug out to form a "concave" structure in the longitudinal section, or the marking plate slide plate 6 can be a stainless steel, aluminum alloy or engineering plastic rectangular block that is stamped to form a "concave" structure in the longitudinal section; or the marking plate slide plate 6 can be a stainless steel or aluminum alloy bottom plate 62 and two side plates 61 that are welded and polished to form a "concave" structure in the longitudinal section. The slide groove 621 on the bottom plate 62 is dug or ground by a milling process of a milling machine or a grinding process of a drilling machine, and the slide grooves 621 are equidistant relative to their respective corresponding sides, so as to ensure that the mark plate 8 is always located at the center of the midline after installation.

[0047] like Figure 4 As shown, a column 52 is vertically arranged on one surface of the marking plate pressing plate 5, so that the longitudinal section of the marking plate pressing plate 5 is in a "丄" structure; a long strip-shaped through hole 51 is opened at the central symmetrical position of the marking plate pressing plate 5. Among them, the marking plate pressing plate 5 is a rectangular plate, and its material can be a hard material such as stainless steel, aluminum alloy or engineering plastic, and the through hole 51 is obtained by stamping or planing; the column 52 is a cylinder, which is fixedly connected to the marking plate pressing plate 5 by screw connection, welding or other fixing methods; or the column 21 and the marking plate pressing plate 5 are integrally formed by blank machine processing.

[0048] like Figure 5 As shown, the marking plate 8 is a block structure, preferably a cube in this embodiment, and a marking line 82 is provided on the upper surface 81 of the marking plate 8, that is, the center position of the surface facing the marking plate pressing plate 5 after installation. The marking line 81 is a cross, a circle, a triangle or other regular bodies; the marking line 82 of the cross structure is selected in this embodiment.

[0049] like Figure 6 As shown, the elastic pressing member 9 is a thin sheet-like pressing spring with a certain elasticity and a "W"-shaped longitudinal section, and the middle of the pressing spring 9 forms an inner concave cavity 91. In this embodiment, the pressing spring 9 with a "W"-shaped structure is preferred, and the size of the inner concave cavity 91 of the pressing spring 9 is adapted to the fixed card column marking plate 8, and the width of the pressing spring 9 is consistent with the width of the slide groove 621. The material of the elastic pressing member 9 is carbon steel, carbon fiber, etc., preferably carbon steel.

[0050] The elastic pressing member 9 can also be a regular cube, such as a cube, a cuboid, a cylinder, an elliptical cylinder, or a triangular prism, etc. At this time, the marking plate 8 is fixedly arranged at the middle position of the regular body.

[0051] Such as Figure 1a , 1b , as shown in 2a and 2b, the positional relationship of each component of the calibration jig 100 is as follows:

[0052] The upper surface of the marking plate pressing plate 5 is fixedly connected to the marking plate sliding plate 6. The lower surface of the marking plate pressing plate 5 is in close contact with the upper surface of the marking plate 8. The lower surface of the marking plate pressing plate 5 is at the same height as the lower surface of the soldering iron tip 4. The pressing spring piece 9 is in close contact with the lower surface of the marking plate 8. The pressing spring piece provides an upward pressing force. The pressing spring piece 9 can slide on the marking plate sliding plate 6. The fine adjustment screw 7 is threadedly connected to the marking plate sliding plate 6. The fine adjustment screw 7 is in close contact with the side surface of the pressing spring piece 9. The marking plate 8 is finely adjusted using the fine adjustment screw 7.

[0053] The specific assembly process of the above calibration jig 100 is as follows:

[0054] 1. Fit and snap the pressing spring piece 9 into the chute 621 of the marking plate sliding plate 6. The pressing spring piece 9 can move relative to the marking plate sliding plate 6 along the length direction in the chute 621. During installation, the concave cavity 91 of the pressing spring piece 9 faces away from the chute 621.

[0055] 2. Fix and snap the marking plate 8 into the elastic pressing member 9, that is, into the concave cavity 91 of the pressing spring piece 9, and the marking line 82 of the marking plate 8 faces away from the chute 621.

[0056] 3. Threadedly screw the fine adjustment screw rod 7 into the threaded through hole 612 and achieve surface contact connection with one side of the pressing spring piece 9. When the fine adjustment screw rod 7 is screwed in, fine adjustment is achieved through the side of the elastic pressing member 9. When the fine adjustment screw rod 7 is screwed out, it pushes the elastic pressing member 9 from the other side until the elastic pressing member 9 is in close contact with the end face of the fine adjustment screw rod 7. In this way, by rotating the fine adjustment screw rod 7, the marking plate 8 is driven to move back and forth in the chute 621.

[0057] 4. Fix and snap both ends of the marking plate pressing plate 5 between the inner walls of the two side plates 61 of the marking plate sliding plate 6, and the upright column 52 of the marking plate pressing plate 5 faces away from the marking plate 8. The lower surface of the marking plate pressing plate 5 is in fitting contact with the upper surface 91 of the marking plate 8, that is, the surface provided with the marking line.

[0058] In the above calibration jig 100, preferably, such as Figure 2bAs shown, the bottom plate 62 of the marker plate slide 6 is provided with through holes 622 along its length direction, which can reduce the weight of the marker plate slide 6. The distances between the through holes 622 and their respective corresponding side edges are equal, and are slightly smaller than the distances between the sliding grooves 621 and their respective corresponding side edges. In this way, a stepped structure is formed between the through holes 622 and the sliding grooves 621. The through holes 622 are opened along the length direction of the bottom plate 62 to the inner walls of the two side plates 61. In this way, after the marker plate 8 moves relative to the marker plate slide 6, the position offset state of the marking line 82 can be observed through the middle through hole 51 on the marker plate pressing plate 5. Then, by rotating the fine adjustment screw rod 7, the marker plate 8 is driven to move slightly in the sliding groove 621, so that the marking line 82 is close to the optical center, realizing the calibration of the offset of the optical center relative to the center of the splitting knife.

[0059] As Figure 2b shown, inner grooves 611 for fixing both ends of the marker plate pressing plate 5 are respectively opened on the inner walls of the two side plates 61 of the marker plate slide 6. Both ends of the marker plate pressing plate 5 are respectively fitted and clamped into the inner grooves 611 of the two side plates 61 to form a firm connection.

[0060] As Figure 6 shown, a central through hole 92 for reducing rigidity and increasing the deformation amount is opened at the concave cavity 91 of the pressing elastic piece 9.

[0061] When the above calibration jig 100 corrects and calibrates the offset of the optical center relative to the center of the splitting knife, the calibration jig 100 will be installed on the semiconductor packaging test workbench. The specific installation and calibration are as follows.

[0062] As Figures 7 to 10 shown, the above calibration jig 100 is installed in the following state:

[0063] An optical lens (referred to as a lens, or a camera lens) 1 and a bonding head 3 are respectively installed on the mounting base 2 of the calibration workbench. The bonding head 3 includes a splitting knife 4 and a splitting knife seat 32. The splitting knife 4 is fixedly installed in the mounting hole 31 at the upper end of the splitting knife seat 32 and can be detachably installed as needed. The lens 1 is installed at the upper end of the lens seat 41; and the lens 1 is installed above the mounting base 2, the bonding head 3 is installed in front of the mounting base 2, the bonding head 3 can rotate in the direction perpendicular to the paper surface, and the splitting knife 4 is installed at the front end of the bonding head 3. When the bonding head 3 rotates relative to the X-axis to the horizontal position, the central axes of the lens 1 and the splitting knife 4 are the same in the Y direction, and there is an offset between the lens 1 and the splitting knife 4 in the X direction, that is, there is an offset amount ⊿X between the axis f of the splitting knife 4 and the axis e of the lens 1 in the X axis direction.

[0064] As Figure 7 and 10As shown, when the above calibration fixture 100 is installed on the bonding head 3, first remove the bonding tool 4 from the mounting hole 31 at the top of the bonding head 3, and then insert the column 52 of the marking plate pressing plate 5 of the above calibration fixture 100 into the mounting hole 31 provided at the top of the bonding head 3 and make the length direction of the above calibration fixture 100 parallel to the plane where the mounting base 2 is located.

[0065] The lens holder 41 is fixed on the mounting base 2, and the bonding tool holder 32 is movably installed on the mounting base 2 and can rotate relative to the X-axis. As Figure 10 and 12 shown, its rotation can be clockwise rotation in the I direction or counterclockwise rotation in the II direction. The bonding head 3 rotates in the plane to realize the height change of the bonding tool 4 at its front end. During the rotation of the bonding head 3, the value of the bonding tool in the ⊿Y direction will also change accordingly.

[0066] As Figure 13 shown, in the present invention, in the optical calibration adjustment process flow of the calibration fixture, the steps are as follows:

[0067] S1. Install the calibration fixture on the bonding head, adjust the sliding of the pressing spring piece 9 and the rotation of the marking plate pressing plate 5 to make the center of the marking line of the marking plate 8 close to the optical center of the lens 1. The marking line is imaged in the camera, and the coordinates (x0, y0) of the center of the marking line in the image are identified through image processing; where x0 is the X-direction coordinate and y0 is the Y-direction coordinate;

[0068] S2. Automatically adjust the height of the bonding head at a certain height interval, and record the X-direction and Y-direction coordinates of the center of the marking line corresponding to the bonding head 3 at each height Hn in the image, which are (xn, Hn) and (yn, Hn) respectively; according to the recorded data, fit the X-direction and Y-direction coordinates of the center of the marking line corresponding to any height H within the working height range in the image, which are (x, H) and (y, H) respectively, and store them in the system database;

[0069] S3. Remove the calibration fixture 100, replace it with the bonding tool 4, and record the current coordinates (X0, Y0) of the mounting base 2; the bonding head 3 makes a mark on the material, and the height of the bonding head 3 with the mark is H1; move the mounting base 2 to make the optical center cursor coincide with the center of the mark, and record the coordinates (X1, Y1) of the mounting base 2 to obtain the offsets (X1 - X0, H1) and (Y1 - Y0, H1) of the optical center relative to the bonding tool 4 in the X-direction and Y-direction respectively when the height of the bonding head is H1. When the height of the bonding head is H1, the X-direction and Y-direction coordinates of the center of the marking line obtained by fitting in the image are (x1, H1) and (y1, H1) respectively;

[0070] S4, the optical pixel equivalent is denoted as a, and the X-direction and Y-direction offsets of the optical center of the bonding head 3 at any height H relative to the splitter 4 are respectively (X1-X0+ax-ax1, H) and (Y1-Y0+ay-ay1, H), thereby realizing optical calibration adjustment.

[0071] Before step S1 of the optical calibration adjustment process, according to the optical calibration requirements, if the calibration fixture is removed, the following steps are also included:

[0072] S0. Install the optical lens 1 and the header 3 on the mounting base 2 of the calibration workbench respectively, with the optical lens 1 located above the mounting base 2 and the rake 4 installed on the header 3.

[0073] Since there are errors in the height of different riving knives 4, if the riving knives 4 are replaced, recalibration and adjustment are required after step S4; the steps at this time are as follows:

[0074] S5. After replacing the rake 4, record the current coordinates (X3, Y3) of the mounting base 2, print a mark on the material, record the height H2 of the print, move the mounting base 2 until the optical center coincides with the mark center, record the coordinates (X4, Y4), and obtain the current height H2 offset (X4-X3, H2) (Y4-Y3, H2); obtain a new X offset of (X4-X3+ax-ax2, H), and a new Y offset of (Y4-Y3+ay-ay2, H).

[0075] In summary, the optical calibration adjustment method of the present invention has the following advantages:

[0076] 1. The marking line is kept near the center of the field of view to identify coordinate points of different heights at a certain height interval, and then the X and Y offset differences within the height range are calculated by fitting;

[0077] 2. The X and Y offsets of any height are calculated by adding the offset difference of the other heights relative to that height.

[0078] 3. Every time the splitter is replaced, recalibrate and calculate the new offset method;

[0079] 4. The combination of the sliding of the marking plate and the rotation of the pressure plate enables the adjustment of the marking plate to any position within a certain offset range;

[0080] 5. The marking plate is compressed and loosened by means of the deformation of the compression spring, so as to achieve sliding and fixing of the marking plate.

[0081] It should be understood that the above description of the preferred embodiments of the present invention is relatively detailed and cannot be regarded as limiting the scope of patent protection of the present invention. The scope of patent protection of the present invention shall be based on the attached claims.

Claims

1. An optical center offset calibration fixture, characterized in that The calibration jig includes a marking plate pressing plate, on the same side of one surface of the marking plate pressing plate, a marking plate and a column are respectively fixedly arranged; the column is perpendicular to the marking plate pressing plate; at the center position of one surface of the marking plate, a marking line is provided, and the marking line is arranged in the same direction as the column; or, the calibration jig includes a marking plate pressing plate, on two opposite and different side surfaces of the marking plate pressing plate, a marking plate and a column are respectively fixedly arranged, and a middle through hole is arranged at the central symmetry position of the marking plate pressing plate; the column is perpendicular to the marking plate pressing plate; at the center position of one surface of the marking plate, a marking line is provided, and the marking line is arranged in the same direction as the column; The calibration jig includes a marking plate sliding plate and an elastic pressing member; wherein: The marking plate sliding plate is plate-shaped and has a longitudinal section in an "inverted U" structure, including a bottom plate and two side plates; on the upper surface of the bottom plate, a downward concave chute is opened in the direction of the two side plates; The elastic pressing member is fitted and clamped into the chute of the marking plate sliding plate and can move relative to the marking plate sliding plate; the marking plate is fixedly arranged on the elastic pressing member, and the marking line of the marking plate faces away from the chute; the two ends of the marking plate pressing plate are fixedly arranged between the two side plates of the marking plate sliding plate, and the lower surface of the marking plate pressing plate is fitted and abutted against the marking line of the marking plate, and the marking line can be observed through the middle through hole of the marking plate pressing plate.

2. The calibration jig according to claim 1, wherein The calibration jig further includes a fine adjustment screw rod; correspondingly, a threaded through hole is arranged on one of the side plates of the marking plate sliding plate block; the fine adjustment screw rod is threadedly screwed into the threaded through hole and is in close contact with the elastic pressing member, and the fine adjustment screw rod can push the elastic pressing member to move relative to the marking plate sliding plate.

3. The calibration jig according to claim 1, wherein, Through holes are opened on the bottom plate of the marking plate sliding plate in the direction of the two side plates, and the through holes and the chute are in a stepped structure.

4. The calibration jig according to claim 1, wherein Inner grooves are opened on the inner walls of the two side plates of the marking plate sliding plate, and the two ends of the marking plate pressing plate are respectively fitted and clamped into the two inner grooves to form a firm connection.

5. The calibration jig according to claim 1, wherein The elastic pressing member is a pressing spring piece with a longitudinal section in a "W" shape, and an inner concave cavity is formed in the middle of the pressing spring piece, and the marking plate is fixedly arranged in the inner concave cavity of the pressing spring piece.

6. The calibration fixture according to claim 5, wherein A central through hole is opened in the inner concave cavity.

7. The calibration jig according to claim 1, wherein The elastic pressing member is a regular body, and the marking plate is fixedly arranged at the middle position of the regular body.

8. The calibration fixture according to claim 1, wherein, The marking line is a cross, a circle, a triangle or other regular bodies.

9. An optical calibration adjustment method for the calibration fixture according to any one of claims 1 to 8, characterized in that, Including the following steps: Install the calibration jig on the bonder head, adjust the elastic pressing member and the marking plate pressing plate to rotate, so that the center of the marking line of the marking plate is close to the optical center of the camera lens, the marking line is imaged in the camera, and the coordinates (x0, y0) of the center of the marking line in the image are identified through image processing; where x0 is the X-direction coordinate and y0 is the Y-direction coordinate; Automatically adjust the height of the bonding head at certain height intervals, and record the X-direction and Y-direction coordinates of the center of the marking line corresponding to each height Hn of the bonding head in the image, which are (xn, Hn) and (yn, Hn) respectively; according to the recorded data, fit the X-direction and Y-direction coordinates of the center of the marking line corresponding to any height H within the working height range in the image, which are (x, H) and (y, H) respectively, and store them in the system database; Remove the calibration jig, replace it with a bonding tool, and record the current mounting base coordinates (X0, Y0); the bonding head makes a mark on the material, and the height of the bonding head when making the mark is H1; move the mounting base to make the optical center cursor coincide with the center of the mark, and record the mounting base coordinates (X1, Y1), to obtain the offsets of the optical center relative to the bonding tool in the X-direction and Y-direction when the bonding head height is H1, which are (X1 - X0, H1) and (Y1 - Y0, H1). When the bonding head height is H1, the X-direction and Y-direction coordinates of the center of the marking line obtained by fitting in the image are (x1, H1) and (y1, H1) respectively; the optical pixel equivalent is denoted as a, and the X-direction and Y-direction offsets of the optical center relative to the bonding tool corresponding to any height H of the bonding head are (X1 - X0 + ax - ax1, H) and (Y1 - Y0 + ay - ay1, H) respectively, to achieve optical calibration adjustment.

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