Bonding chopper

Abstract

The utility model relates to a bonding chopper. The bonding chopper comprises a main body, and the main body is provided with a through hole penetrating through the main body in the axis direction of the main body. The head portion of the body is provided with an end face intersecting with the inner circumferential surface of the through hole, the end face is composed of protruding parts and concave parts which are distributed alternately, and the cross section of each concave part formed between every two adjacent protruding parts is in a V shape.

Description

Technical Field

[0001] The present application mainly relates to the technical field of semiconductor chip packaging ultrasonic welding tools. More specifically, the present application relates to a bonding knife for bonding metal wires to bond pads / leads. Background Art

[0002] At present, the packaging process is a crucial step in the production process of semiconductor chips. Wire bonding technology is one of the most commonly used technologies in the packaging process, which is used to weld the two ends of the metal lead to the pads of the die and the pads of the pins respectively to achieve electrical connection between the die and the pins.

[0003] Typically, wire bonding includes the steps of forming a first bonding point (also known as ball bonding) and forming a second bonding point. When bonding the second bonding point, the bonding cutter squeezes the metal wire in the vertical direction through its end face. The metal wire receives the ultrasonic energy transmitted from the end face and becomes a semi-fluid state, and the metal wire in the semi-fluid state is then connected to the pad. When the wire bonding system stops supplying ultrasonic energy, the metal wire quickly returns to a solid state. Subsequently, the bonding cutter moves upward in the vertical direction, driving the metal wire in the bonding cutter through hole to be entangled with the metal wire connected to the pad and then disconnected. As a result, the second bonding point is bonded, and the second bonding point forms a fishtail shape on the pad.

[0004] It can be seen that the bonding knife is a key tool for wire bonding, which has a decisive influence on the bonding quality. Therefore, there is a need in the art to continuously improve various aspects of the bonding knife to achieve more optimized bonding performance. Utility Model Content

[0005] The purpose of the present application is to provide a novel bonding knife, which can improve the bonding performance.

[0006] According to one aspect of the present application, a bonding cutter is provided. The bonding cutter comprises a main body, the main body is provided with a through hole penetrating the main body along the direction of its axis, and the head of the main body has an end face intersecting with the inner peripheral surface of the through hole. The end face is composed of alternately distributed protruding parts and recessed parts, wherein the cross section of the recessed part formed between adjacent protruding parts is V-shaped.

[0007] Preferably, the top surfaces of the protruding portions are all located in the same plane perpendicular to the axis of the bonding cutter.

[0008] Preferably, the top surfaces of the protruding portions are all located on the same conical surface, wherein an angle FA between the conical surface and a plane perpendicular to the axis of the bonding cutter is greater than 0 degrees and less than or equal to 15 degrees.

[0009] Preferably, a height difference between the top surface of the protruding portion and the lowest point of the recessed portion is greater than or equal to 1 micrometer and less than or equal to 10 micrometers.

[0010] Preferably, at least a portion of the protruding portion is a regular polygonal pyramid.

[0011] Preferably, the protruding portion which is a regular polygonal pyramid forms at least one annular band around the center of the end face, wherein the protruding portions in the same annular band have the same size and shape.

[0012] Preferably, the inner cone angle ha of the regular polygonal pyramid ranges from greater than or equal to 30 degrees to less than or equal to 60 degrees.

[0013] Preferably, the regular polygonal pyramid is formed as a regular hexagonal pyramid.

[0014] Preferably, the length of the base side of the regular hexagonal pyramid is greater than or equal to 3 micrometers and less than or equal to 12 micrometers, and the length of the top side is greater than or equal to 1.5 micrometers and less than or equal to 6 micrometers.

[0015] Preferably, the regular polygonal pyramid is formed as a regular quadrangular pyramid.

[0016] Preferably, the length of the bottom side of the regular quadrangular pyramid is greater than or equal to 4 micrometers and less than or equal to 16 micrometers, and the length of the top side is greater than or equal to 2 micrometers and less than or equal to 8 micrometers.

[0017] Preferably, the regular polygonal pyramid is formed as a regular triangular pyramid.

[0018] Preferably, the length of the base side of the regular triangular prism is greater than or equal to 5 micrometers and less than or equal to 20 micrometers, and the length of the top side is greater than or equal to 2.5 micrometers and less than or equal to 10 micrometers.

[0019] Preferably, the surface roughness of the top surface of the protruding portion is greater than or equal to 0 micrometers and less than or equal to 1 micrometer.

[0020] It should be understood that the above general description and the following detailed description are only exemplary and illustrative, rather than limiting the present invention. In addition, the accompanying drawings, which are incorporated into and constitute a part of this specification, illustrate embodiments of the present invention and are used together with the specification to explain the principles and concepts of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The above and other features of the present invention will be more fully understood through the following description and the attached claims in conjunction with the accompanying drawings. It is understood that these drawings only depict several embodiments of the present application and should not be considered as limiting the scope of the present application. By referring to the accompanying drawings, the present application will be more clearly and in detail described.

[0022] Figure 1 A perspective view of a bonding tool in the prior art is shown as an example.

[0023] Figures 2A to 2F A bonding knife according to a first embodiment of the present application is exemplarily shown.

[0024] Figures 3A to 3E A bonding knife according to a second embodiment of the present application is exemplarily shown.

[0025] Figures 4A to 4C A top view of a bonding knife according to a third embodiment of the present application is exemplarily shown.

[0026] Description of reference numerals:

[0027] Bonding knife: 100, 200, 300

[0028] External wall of the main body: 100b, 200b

[0029] Body: 10

[0030] Base: 10a

[0031] Head: 10b

[0032] Metal leads: 11

[0033] Through hole: 12, 101, 201

[0034] Cylindrical surface: 101a, 201a

[0035] Inner conical surface: 101b, 201b

[0036] End face: 102, 202, 302

[0037] Outer transition surface: 103, 203

[0038] Protrusions: 104, 104-i, 204, 204-i, 304, 304-i

[0039] Vertex: 104a, 204a, 304a

[0040] Recessed part: 105, 105-i, 205, 205-i, 305, 305-i DETAILED DESCRIPTION

[0041] In the following detailed description, reference is made to the drawings that form part of the present application. In the drawings, similar symbols generally represent similar components unless the context otherwise indicates. The illustrative embodiments described in the detailed description, drawings, and claims are not intended to be limiting. Other embodiments may be adopted and other changes may be made without departing from the spirit or scope of the subject matter of the present application. It is understood that various configurations, substitutions, and combinations of various different compositions may be made to the various aspects of the content of the present application generally described in the present application and illustrated in the drawings, and all of these should not be construed as limiting the scope of protection of the present application. The scope of protection of the present application shall be subject only to the limitations of the attached claims.

[0042] In this application, unless otherwise expressly stated, the use of singular words shall also include the plural meaning. In this application, unless otherwise stated, the use of "or" means "and / or". In addition, the use of the term "including" and other forms of expression such as "including" and "containing" are not limiting. In addition, the section headings used in this specification are for organizational purposes only and should not be interpreted as limiting the subject matter described.

[0043] As used herein, the "distal end" of a bonding knife refers to the end of the bonding knife used to press the metal lead to form a bonding point, while the "proximal end" of the bonding knife is the end opposite the "distal end". Spatially relative terms, such as "upper", "lower", "left", "right", etc., are convenient for describing the relationship of one element or feature to another element or feature as shown in the accompanying drawings. In addition to the orientation depicted in the figures, the spatially relative terms are intended to encompass different orientations of the bonding knife in use or operation. The bonding knife may be otherwise oriented (rotated 90 degrees, 180 degrees or at other orientations), and the spatially relative descriptors used herein should be interpreted accordingly.

[0044] In this document, for various numerical ranges, unless otherwise specified, the end values ​​of the range should be included.

[0045] Figure 1 FIG. 1 is a schematic perspective view of a conventional bonding tool in a working position, wherein a metal lead 11 for bonding passes through a through hole 12 located in the center area of ​​the bonding tool. Figure 1As shown, the bonding knife includes a main body 10, and the main body 10 has a base 10a located at the proximal end and a head 10b located at the distal end. The base 10a is used to be installed on the frame of the wire bonding system (for example, a wire bonding machine), and the head 10b is used to make the metal wire 11 contact the pad with pressure for bonding. The main body 10 of the bonding knife is provided with a through hole 12 extending along its axial direction Y. The metal wire 11 penetrates into the through hole 12 from the base 10a at the proximal end of the bonding knife, and extends out of the head 10b from the distal end of the bonding knife. It can be understood that the wire bonding system is provided with a clamp for controlling the movement of the metal wire 11. When the clamp clamps the metal wire 11, the metal wire 11 cannot move relative to the bonding knife; when the clamp releases the metal wire 11, the metal wire 11 can move along the axis Y in the through hole 12 of the bonding knife.

[0046] Figures 2A to 2F A bonding knife 100 according to a first embodiment of the present application is shown, wherein Figure 2A is a perspective view of a bonding tool 100; Figure 2B is from Figure 2A A top view of the bonding tool 100 viewed from above; Figure 2C FIG. 1 is a top view of the bonding tool 100 , wherein the annular band formed by the protruding portion is schematically marked with a black dotted line; Figure 2D yes Figure 2B A partial enlarged view of the portion within the dotted frame in FIG. Figure 2E The edge of the bonding knife Figure 2B Longitudinal section along the midline AA, Figure 2F yes Figure 2E A partial enlarged view of the part within the dotted box.

[0047] refer to Figures 2A to 2F ,and Figure 1 Similar to the conventional bonding cleaver shown in the figure, the bonding cleaver 100 includes a main body having a through hole 101 extending from the proximal end of the main body along the axis Y of the main body to the distal end side of the main body. The through hole 101 includes a cylindrical surface 101a with a diameter H and an inner conical surface 101b, and the inner conical surface 101b is at its distal end (i.e. Figure 2E and Figure 2F The top side of the through hole 101 has a maximum diameter CD and an inner cone angle ICA. Of course, in some variant embodiments, the through hole 101 may also include only a cylindrical inner surface without an inner conical surface, and the present application does not limit this.

[0048] The head of the main body has an end face 102, an outer transition surface 103 and an outer side wall 100b. One end of the end face 102 is connected to the outer side wall 100b of the main body through the outer transition surface 103, and the other end is connected to the inner peripheral surface of the through hole 101 (at Figure 2FThe outer transition surface 103 is constructed as a rounded surface with a rounded radius of OR. The extended portion of the outer side wall 100b of the bonding knife 100 intersects with the horizontal plane L / P to form a ring with a diameter of T, wherein the horizontal plane L / P is perpendicular to the axis Y of the main body and intersects with the farthest end of the bonding knife 100. The proximal side of the main body is connected to a wire bonding system (e.g., a wire bonding machine, not shown). The structure and shape of the main body of the bonding knife 100 of the present application can be adopted Figure 1 As long as the distal end of the bonding knife 100 has Figures 2A to 2F The structure shown is sufficient.

[0049] The inventor of the present application has found that when the existing bonding knife is used for wire bonding, especially for bonding at the second bonding point, if the surface of the end face of the bonding knife is relatively smooth, relative sliding (i.e., slipping) is very likely to occur between the heated and molten metal wire and the end face of the bonding knife, thereby affecting the bonding quality of the second bonding point and the fishtail shape formed at the second bonding point. In view of this, the inventor of the present application aims to design an improved bonding knife to reduce the generation of the above-mentioned relative sliding and thus enhance the bonding quality of the second bonding point.

[0050] Continue to refer to the attached Figures 2A to 2F The end surface 102 is alternately provided with protruding portions 104 and recessed portions 105, wherein the cross section of the recessed portions 105 between adjacent protruding portions 104 is V-shaped. Figures 2A to 2F In the embodiment of the present invention, the protruding portion 104 located in the middle of the end face 102 is constructed as a regular hexagonal pyramid, while the portion of the end face 102 close to the through hole 101 and the outer transition surface 103 is in the form of a regular hexagonal pyramid truncated by the corresponding outer transition surface and through hole surface, so that the end face 102 is projected on the plane P to form a substantially circular outer contour. The side surface of the protruding portion 104 located at the intersection of the end face 102 and the through hole 101 forms a part of the inner surface of the through hole 101. Similarly, the side surface of the protruding portion 104 located at the intersection of the end face 102 and the outer transition surface 103 forms a part of the outer transition surface 103.

[0051] In some embodiments, Figure 2CAs shown in the figure, the protruding portion 104 in the form of a regular hexagonal prism forms two roughly hexagonal annular bands around the center of the end face 102 (the black dotted line in the figure passes through the top center of the protruding portion 104 in the same annular band). The number of annular bands can be adjusted arbitrarily according to actual conditions (such as the size of the end face, the size of the protruding portion 104, etc.), for example, it can be 1, 3, 4, 5, etc. The protruding portions 104 in the same annular band have the same size and shape. From all angles of the circumference with the center of the end face 102 as the center, the same annular band is centrally symmetrical around the center of the end face 102.

[0052] refer to Figure 2E and Figure 2F , the regular polygonal pyramid-shaped protrusion 104 has an inner cone angle ha. Obviously, the angle h of the V-shaped cross section of the concave portion 105 is b With the inner cone angle h a Therefore, by setting a suitable inner cone angle ha, the sharpness of the top of the protruding portion 104 and the sharpness of the recessed portion 105 can be controlled, thereby controlling the efficiency of ultrasonic energy being transmitted to the metal lead, and effectively preventing the metal lead from slipping relative to the end face 102 during the bonding process.

[0053] However, when the value of the inner cone angle ha increases to a value exceeding a certain value, the end face 102 is too flat, and it is easy to cause undesirable lateral slippage when bonding at the second bonding point. When the value of the inner cone angle ha decreases to a value exceeding a certain value, the end face 102 becomes too rough, and more metal lead material enters the recessed portion 105, so that the end face 102 is easy to adhere to the molten metal lead, which is not conducive to the bonding knife 100 separating the metal lead in its through hole 101 from the metal lead that has been bonded to the second bonding point, thereby completing the bonding of the second bonding point.

[0054] Therefore, it is necessary to set a suitable range of the inner cone angle ha of the regular polygonal pyramid. The inventors of the present application have found that when the inner cone angle ha of the regular polygonal pyramid is greater than or equal to 30 degrees and less than or equal to 60 degrees, a particularly good effect can be produced.

[0055] Continue to refer Figure 2E , the top surface of the protruding portion 104 has a height h relative to the lowest point of the recessed portion 105. The inventors of the present application have found that when the height h of the protruding portion 104 is within a certain numerical range, for example, when the height h of the protruding portion 104 is greater than or equal to 1 micron and less than or equal to 10 microns, the bonding ability of the bonding knife will reach the optimum. If the height h of the protruding portion 104 is further increased beyond this range, it is difficult to improve, or may even reduce, the bonding ability of the bonding knife. If the height h is further reduced beyond this range, it may not be possible to effectively prevent relative sliding between the metal lead and the end surface.

[0056] Continue to refer Figure 2D The protruding portion 104 is constructed as a regular hexagonal pyramid, and the bases of adjacent protruding portions 104 are collinear with each other. The protruding portions 104-1, 104-2, and 104-3 have a common vertex 104a, a concave portion 105-1 formed between the protruding portions 104-1 and 104-2, a concave portion 105-2 formed between the protruding portions 104-2 and 104-3, and a concave portion 105-3 formed between the protruding portions 104-1 and 104-3. The three concave portions 105-1, 105-2, and 105-3 meet at the vertex 104a of the base of the protruding portion 104, and the three concave portions 105 are distributed at equal angles (forming an angle of 120 degrees with each other) on the circumference of a circle with the vertex 104a as the center. In certain preferred embodiments, the length of the base side of the regular hexagonal pyramid is greater than or equal to 3 microns and less than or equal to 12 microns, and the length of the top side is greater than or equal to 1.5 microns and less than or equal to 6 microns.

[0057] exist Figures 2A to 2F In the embodiment of the present invention, the top surface of the protruding portion 104 is located on the same plane P, the plane P is perpendicular to the axis Y of the bonding knife 100, and coincides with the horizontal plane L, that is, the angle FA formed by the plane P and the horizontal plane L is equal to 0 degrees. In some other embodiments, the top surface of the protruding portion 104 can be located on the same conical surface (not shown), and the angle between the conical surface and the horizontal plane L is FA. The inventors of the present application have found that when the angle FA is designed to be greater than 0 degrees and less than or equal to 15 degrees, the bonding knife 100 has a better bonding ability.

[0058] In some embodiments, the top surface of the protruding portion 104 may be roughened to further increase the roughness of the end surface of the bonding knife 100, so as to further increase the friction between the metal lead and the end surface of the bonding knife, and prevent relative sliding between the metal lead and the bonding knife during the bonding process. Preferably, the top surface of the protruding portion has a roughness of greater than or equal to 0 micrometers and less than or equal to 1 micrometer.

[0059] Example 1

[0060] For those with Figures 2A to 2FThe embodiment 1 of the bonding wedge of the structure shown is as follows: the inner diameter H of the cylindrical inner surface 101a is 22 microns, the conical inner surface 101b has a maximum diameter CD of 30 microns and an inner cone angle ICA of 90 degrees. The angle FA between the conical surface where the top surface of the protruding portion 104 is located and the horizontal plane L is 8 degrees, the top surface side length of the protruding portion 104 of the regular hexagonal pyramid is 5 microns, the bottom side length is 10 microns, and the inner cone angle ha is 45 degrees. The diameter T of the annular surface formed by the extension of the outer side wall 100b of the main body of the bonding wedge 100 intersecting with the horizontal plane L is 100 microns, and the rounded radius OR of the outer transition surface 103 is 15 microns.

[0061] Figures 3A to 3E The head of a bonding knife 200 according to the second embodiment of the present application is shown. Figure 3A is a three-dimensional diagram of a bonding tool 200. Figure 3B is from Figure 3A A top view of the bonding tool 200 viewed from above, Figure 3C yes Figure 3B A partial enlarged view of the part within the dotted box in Figure 3D The edge of the bonding knife Figure 3B Longitudinal section along the midline BB, Figure 3E yes Figure 3D A partial enlarged view of the part within the dotted box.

[0062] and Figures 2A to 2F The bonding tool 100 shown is compared to Figures 3A to 3E The main difference of the bonding knife 200 shown is that the protrusion 204 is configured as a regular triangular pyramid.

[0063] like Figure 3CAs shown, the bottom edges of adjacent protrusions 204 of the bonding knife 200 are closely attached to each other and share a bottom edge. The protrusions 204-1, 204-2, 204-3, 204-4, 204-5 and 204-6 have a common vertex 204a, a concave portion 205-1 formed between the protrusions 204-1 and 204-2, a concave portion 205-2 formed between the protrusions 204-2 and 204-3, a concave portion 205-3 formed between the protrusions 204-3 and 204-4, and a concave portion 205-4 formed between the protrusions 204-4 and 204-5. The concave portion 205-4 formed between the protruding portions 204-5 and 204-6, the concave portion 205-5 formed between the protruding portions 204-1 and 204-6, the concave portion 205-6 formed between the protruding portions 204-1 and 204-6, the concave portions 205-1, 205-2, 205-3, 205-4, 205-5 and 205-6 meet at the vertex 204a, and are distributed at equal angles (60 degrees to each other) on the circumference of the circle with the vertex 204a as the center. In some preferred embodiments, the length of the base of the regular triangular prism is greater than or equal to 5 microns and less than or equal to 20 microns, and the length of the top surface is greater than or equal to 2.5 microns and less than or equal to 10 microns.

[0064] Example 2

[0065] For those with Figures 3A to 3E The embodiment 2 of the bonding cutter 200 of the structure shown is as follows: the inner diameter H of the cylindrical inner surface 201a is 22 microns, the conical inner surface 201b has a maximum diameter CD of 29 microns and an inner cone angle ICA of 90 degrees. The angle FA between the plane P where the top surface of the protruding portion 204 is located and the horizontal plane L is 8 degrees, the height h of the protruding portion 204 of the regular triangular prism is 1 micron, and the inner cone angle ha corresponding to the regular triangular prism is 30 degrees. The diameter T of the annular surface formed by the extension of the outer side wall 200b of the main body of the bonding cutter 200 intersecting with the horizontal plane L is 100 microns, and the rounded radius OR of the outer transition surface 203 is 12 microns.

[0066] Figures 4A to 4B The head of a bonding knife 300 according to the third embodiment of the present application is shown. Figure 4A is a top view of the bonding knife 300, Figure 4B For Figure 4A A schematic diagram of the ring belt is shown using a black dotted line based on Figure 4C yes Figure 4A A partial enlarged view of the part within the dotted box.

[0067] like Figures 4A to 4C As shown, Figures 3A to 3E The bonding tool 200 shown and Figures 2A to 2FCompared with the bonding knife 100 shown in FIG. 1 , the bonding knife 300 is mainly different in that the protrusion 304 is configured as a regular quadrangular pyramid. The bottom edges of adjacent protrusions 304 are closely attached to each other and share a common bottom edge. Figure 4B As shown in the black dotted frame, the protruding portion 304 in the form of a regular quadrangular pyramid on the end surface 302 of the bonding knife 300 only forms a (roughly square) annular band.

[0068] like Figure 4C As shown, the protruding parts 304-1, 304-2, 304-3 and 304-4 have a common vertex 304a, a concave part 305-1 is formed between the protruding parts 304-1 and 304-2, a concave part 305-2 is formed between the protruding parts 304-2 and 304-3, a concave part 305-3 is formed between the protruding parts 304-3 and 304-4, and a concave part 305-4 is formed between the protruding parts 304-1 and 304-4. The concave parts 305-1, 305-2, 305-3 and 305-4 meet at the vertex 304a and are distributed at equal angles (at an angle of 90 degrees) on the circumference with the vertex 304a as the center. In some preferred embodiments, the length of the bottom side of the regular quadrangular pyramid is greater than or equal to 4 microns and less than or equal to 16 microns, and the length of the top surface is greater than or equal to 2 microns and less than or equal to 8 microns.

[0069] Example 3

[0070] For those with Figures 4A to 4C The embodiment 3 of the bonding cutter 300 of the structure shown is as follows: the inner diameter H of the cylindrical inner surface is 22 microns, the conical inner surface has a maximum diameter CD of 30 microns and an inner cone angle ICA of 90 degrees. The angle FA between the conical surface where the top surface of the protrusion 304 is located and the horizontal plane L is 8 degrees, the height h of the regular tetrahedron is 10 microns, and the inner cone angle ha corresponding to the regular tetrahedron is 60 degrees. The diameter T of the annular surface formed by the extension of the outer side wall of the main body of the bonding cutter 300 intersecting with the horizontal plane L is 100 microns, and the rounded radius OR of the outer transition surface is 15 microns.

[0071] Example 4

[0072] The inner diameter H of the cylindrical inner surface is 30 microns, and the conical inner surface has a maximum diameter CD of 38 microns and an inner cone angle ICA of 70 degrees. The angle FA between the conical surface where the top surface of the protruding part is located and the horizontal plane L is 11 degrees, and the height h of the regular tetrahedron is 2 microns. At this time, the inner cone angle ha corresponding to the regular tetrahedron is 45 degrees. The diameter T of the annular surface formed by the extension of the outer side wall of the main body of the bonding wedge intersecting with the horizontal plane L is 100 microns, and the rounded radius OR of the outer transition surface is 12 microns.

[0073] Comparative Example 1

[0074] The end face of the bonding cutter of comparative example 1 is a flat surface, on which no protrusions or recesses are arranged. Specifically, the scheme of comparative example 1 is as follows: the inner diameter H of the cylindrical inner surface is 22 microns, the conical inner surface has a maximum diameter CD of 30 microns and an inner cone angle ICA of 90 degrees. The angle FA between the end face of the bonding cutter and the horizontal plane L is 8 degrees. The diameter T of the annular surface formed by the extension of the outer side wall of the main body of the bonding cutter intersecting with the horizontal plane L is 100 microns, and the rounded radius OR of the outer transition surface is 15 microns.

[0075] Comparative Example 2

[0076] The end face of the bonded splitter of Comparative Example 2 is a flat surface, on which no protrusions or recesses are arranged. Specifically, the scheme of Comparative Example 2 is as follows: the inner diameter H of the cylindrical inner surface is 22 microns, and the conical inner surface has a maximum diameter CD of 29 microns and an inner cone angle ICA of 90 degrees. The angle FA between the end face of the bonded splitter and the horizontal plane L is 8 degrees. The diameter T of the annular surface formed by the extension of the outer side wall of the main body of the bonded splitter intersecting with the horizontal plane L is 100 microns, and the rounded radius OR of the outer transition surface is 12 microns.

[0077] Comparative Example 3

[0078] The end face of the bonded splitter of Comparative Example 3 is a flat surface, on which no protrusions or recesses are arranged. Specifically, the scheme of Comparative Example 3 is as follows: the inner diameter H of the cylindrical inner surface is 22 microns, and the conical inner surface has a maximum diameter CD of 30 microns and an inner cone angle ICA of 90 degrees. The angle FA between the end face of the bonded splitter and the horizontal plane L is 8 degrees. The diameter T of the annular surface formed by the extension of the outer side wall of the main body of the bonded splitter intersecting with the horizontal plane L is 100 microns, and the rounded radius OR of the outer transition surface is 15 microns.

[0079] Comparative Example 4

[0080] The end face of the bonded splitter of Comparative Example 4 is a flat surface, on which no protrusions or recesses are arranged. Specifically, the scheme of Comparative Example 4 is as follows: the inner diameter H of the cylindrical inner surface is 30 microns, the conical inner surface has a maximum diameter CD of 38 microns and an inner cone angle ICA of 70 degrees. The angle FA between the end face of the bonded splitter and the horizontal plane L is 11 degrees. The diameter T of the annular surface formed by the extension of the outer side wall of the main body of the bonded splitter intersecting with the horizontal plane L is 100 microns, and the rounded radius OR of the outer transition surface is 12 microns.

[0081] The inventor of the present application performed wire bonding operations on a nickel-palladium-gold frame by using a bonding machine with bonding splitters of Examples 1 to 4 and bonding splitters of Comparative Examples 1 to 4. The specific test method is: use a bonding machine to apply an upward force to the lead near the second bonding point, and record the peak value of the tension when the upward force breaks the lead, as the tension value of the second bonding point. The greater the tension value of the second bonding point, the greater the bonding force between the lead and the frame, and the better the bonding effect of the second bonding point. The specific test results are shown in Table 1.

[0082] Table 1

[0083]

[0084]

[0085] Note: The types of leads used for the tests are listed in brackets in this table.

[0086] As can be seen from the above table, compared with the bonding wedges in the prior art, the bonding wedge of the present application significantly improves the tensile force value of the second bonding point by improving the structure of the bonding wedge end face. The tensile force value at the second bonding point formed by the bonding wedges of Examples 1-4 is significantly increased compared with the tensile force value at the second bonding point formed by the bonding wedges of Comparative Examples 1 to 4, with an increase of at least more than 20% and even up to 130%.

[0087] Continuing to refer to Table 1, as the number of bonding increases, the attenuation degree of the tensile force value of the second bonding point formed by the bonding splitting knife embodiments 1-4 of the present application is significantly less than that of comparative examples 1-4. In particular, when the number of tests using the bonding splitting knife of embodiments 1 to 4 reaches 800 thousand times, the tensile force value of the second bonding point measured is still significantly higher than the tensile force value at the second bonding point formed by the bonding splitting knife of comparative examples 1 to 4. In particular, for embodiment 4, when the number of tests using the bonding splitting knife of embodiment 4 reaches 1600 thousand times, the tensile force value of the second bonding point measured can still meet the engineering requirements. However, the tensile force value of the second bonding point formed by the bonding splitting knife of comparative example 4 decays very quickly, and decays rapidly after 800 thousand wire bondings and no longer meets the engineering requirements, and cannot be used any more.

[0088] Therefore, the bonding knife of the present application can ensure the bonding quality of the second bonding point for a longer period of time, that is, it has a longer service life. The application of the bonding knife of the present application provides new ideas and methods for solving challenging product problems, allowing technicians in this field to more flexibly deal with various problems in the bonding process, improve the bonding ability of the bonding knife, and promote the development of the bonding process.

[0089] Although the various embodiments of the present application use metal leads with different properties and nickel-palladium-gold frames as welding materials, the present application does not limit the welding materials, and those skilled in the art can understand that any suitable form of welding materials can be used in the various embodiments of the present application.

[0090] Although it is not clearly shown in the various embodiments shown in the drawings of the present application, those skilled in the art can understand that, in order to improve the bonding effect, an arcuate transition surface can be provided at the junction of each surface in the bonding wedge. For example, an arcuate transition portion is provided at the junction of the cylindrical surface of the through hole and the inner conical surface, and an arcuate transition portion is provided at the junction of the inner conical surface and the end surface, etc. Those skilled in the art can make any combination according to actual needs.

[0091] A person skilled in the art may use appropriate existing measurement methods to determine the height, inner cone angle, bottom side length and top side length of the protruding portion, for example, by using 3D scanning to measure these parameters, which is not limited in the present application.

[0092] The discussion herein includes many illustrative drawings, which respectively show the structures of the distal ends of the bonded riving knives of different embodiments. For the sake of clarity, these figures do not show all aspects of each embodiment. Any embodiment provided herein may share any or all features with any or all other embodiments provided herein, and the features of different embodiments may be arbitrarily combined as needed, all within the scope of protection of this application.

[0093] Various embodiments have been described herein with reference to the accompanying drawings. However, it is apparent that various modifications and changes may be made thereto, and additional embodiments may be implemented without departing from the broader scope of the present invention as set forth in the appended claims. In addition, by considering the specification and the practice of one or more embodiments of the present invention disclosed herein, other embodiments will be apparent to those skilled in the art. Therefore, the present application and the embodiments herein are intended to be considered merely exemplary, and the true scope and spirit of the present invention are indicated by the list of the appended exemplary claims.

Claims

1. A bonding tool, comprising: A main body, wherein the main body is provided with a through hole penetrating the main body along the direction of its axis, and the head of the main body has an end face intersecting with the inner peripheral surface of the through hole, characterized in that the end face is composed of alternately distributed protruding parts and recessed parts, wherein the cross-section of the recessed part formed between adjacent protruding parts is V-shaped.

2. The bonding tool according to claim 1, characterized in that: The top surfaces of the protruding parts are all located in the same plane perpendicular to the axis of the bonding cutter.

3. The bonding tool according to claim 1, characterized in that: The top surfaces of the protruding portions are all located on the same conical surface, wherein an angle FA between the conical surface and a plane perpendicular to the axis of the bonding cutter is greater than 0 degrees and less than or equal to 15 degrees.

4. The bonding tool according to any one of claims 1 to 3, characterized in that: A height difference between the top surface of the protruding portion and the lowest point of the recessed portion is greater than or equal to 1 micrometer and less than or equal to 10 micrometers.

5. The bonding tool according to claim 1, characterized in that: At least a portion of the protruding portions is a regular polygonal pyramid.

6. The bonding tool according to claim 5, characterized in that: The protruding portion of the regular polygonal pyramid forms at least one annular band around the center of the end face, wherein the protruding portions in the same annular band have the same size and shape.

7. The bonding tool according to claim 5 or 6, characterized in that: The inner cone angle ha of the regular polygonal pyramid ranges from greater than or equal to 30 degrees to less than or equal to 60 degrees.

8. The bonding tool according to claim 5 or 6, characterized in that: The regular polygonal pyramid is formed as a regular hexagonal pyramid.

9. The bonding tool according to claim 7, characterized in that: The regular polygonal pyramid is formed as a regular hexagonal pyramid.

10. The bonding tool according to claim 8, characterized in that: The length of the bottom side of the regular hexagonal pyramid is greater than or equal to 3 micrometers and less than or equal to 12 micrometers, and the length of the top side is greater than or equal to 1.5 micrometers and less than or equal to 6 micrometers.

11. The bonding tool according to claim 9, characterized in that: The length of the bottom side of the regular hexagonal pyramid is greater than or equal to 3 micrometers and less than or equal to 12 micrometers, and the length of the top side is greater than or equal to 1.5 micrometers and less than or equal to 6 micrometers.

12. The bonding tool according to claim 5 or 6, characterized in that: The regular polygonal pyramid is formed as a regular quadrangular pyramid.

13. The bonding tool according to claim 7, characterized in that: The regular polygonal pyramid is formed as a regular quadrangular pyramid.

14. The bonding tool according to claim 12, characterized in that: The length of the bottom side of the regular tetrahedron is greater than or equal to 4 micrometers and less than or equal to 16 micrometers, and the length of the top side is greater than or equal to 2 micrometers and less than or equal to 8 micrometers.

15. The bonding tool according to claim 13, characterized in that: The length of the bottom side of the regular tetrahedron is greater than or equal to 4 micrometers and less than or equal to 16 micrometers, and the length of the top side is greater than or equal to 2 micrometers and less than or equal to 8 micrometers.

16. The bonding tool according to claim 5 or 6, characterized in that: The regular polygonal pyramid is formed as a regular triangular pyramid.

17. The bonding tool according to claim 7, characterized in that: The regular polygonal pyramid is formed as a regular triangular pyramid.

18. The bonding tool according to claim 16, characterized in that: The length of the base side of the regular triangular prism is greater than or equal to 5 micrometers and less than or equal to 20 micrometers, and the length of the top side is greater than or equal to 2.5 micrometers and less than or equal to 10 micrometers.

19. The bonding tool according to claim 17, characterized in that: The length of the base side of the regular triangular prism is greater than or equal to 5 micrometers and less than or equal to 20 micrometers, and the length of the top side is greater than or equal to 2.5 micrometers and less than or equal to 10 micrometers.

20. The bonding tool according to any one of claims 1 to 3, characterized in that: The surface roughness of the top surface of the protruding portion is greater than or equal to 0 micrometers and less than or equal to 1 micrometer.

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