A method of using a wedge bonding structure

Abstract

The application relates to the technical field of microelectronic packaging, and particularly discloses a wedge-shaped bonding structure and a use method thereof, wherein the wedge-shaped bonding structure is used for wire bonding and comprises a wedge and a wire clamp used in cooperation with the wedge; the wire clamp comprises a clamping part and a body connected with the clamping part; a wire via hole and a wire limiting groove in communication with the wire via hole and arranged close to one side of the wedge are arranged on the body; and a use method thereof is disclosed; compared with the wedge structure in the prior art, the wedge structure is simplified, the processing difficulty and cost of the wedge are reduced; when the wedge is scrapped, only the wedge needs to be replaced, and the wire clamp can be used for a long time; the structure is simple and practical.

Description

Technical Field

[0001] The present invention relates to the technical field of microelectronic packaging, and more particularly to a method for using a wedge-shaped bonding structure. Background Art

[0002] Wire bonding technology is categorized into ball bonding and wedge bonding. Ball bonding offers the advantage of high bonding speed, but has the disadvantage of low bonding density and inability to bond ultra-low wire arcs. In high-density, high-frequency integrated circuit packaging, a hybrid of ball bonding and wedge bonding is often employed for automation.

[0003] The spherical bonding wedge has a cylindrical hollow pointed structure and can be processed into a bonding wedge by using ceramic production technology for die casting, sintering and precision turning, and non-conductive ceramic materials.

[0004] Due to their complex structure, wedge-shaped cutters are currently typically manufactured from conductive materials such as cemented carbide and cermets, requiring both machining and EDM processes. However, other non-conductive materials with higher hardness, such as ceramics and diamond, are not suitable for EDM processing due to their inherent properties and are therefore not currently used as wedge-shaped cutter materials.

[0005] Cemented carbide and cermet materials are both manufactured using powder metallurgy. Silicon often adheres to the blade during use, reducing the roughness of the blade's bonding end face and impacting ultrasonic transmission efficiency. Furthermore, high-frequency friction causes powder particles to gradually fall off the blade's pad during use. As these particles fall, the blade gradually ages and wears, leading to a rapid decrease in the number of effective bonding points and process stability, impacting both bonding stability and parameter normalization. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a method for using a wedge-shaped bonding structure. Compared with the wedge structure in the prior art, the wedge structure is simplified, and the difficulty and cost of wedge processing are reduced. When the wedge is scrapped, only the wedge needs to be replaced, and the wire clamp can be used for a long time.

[0007] The solution adopted by the present invention to solve the technical problem is:

[0008] on the one hand:

[0009] The present invention discloses a wedge-shaped bonding structure for bonding wires; it comprises a wedge and a wire clamp used in conjunction with the wedge; the wire clamp comprises a clamping portion and a body connected to the clamping portion;

[0010] The main body is provided with a lead wire through hole and a lead wire limiting groove which is communicated with the lead wire through hole and is arranged close to one side of the cleaver.

[0011] In some possible implementations,

[0012] The lead through hole includes a vertically arranged through hole 1 and an inclined through hole 2; an end of the through hole 2 away from the through hole 1 is connected to the lead limiting groove; the axes of the through hole 1, the through hole 2 and the lead limiting groove are on the same plane.

[0013] In some possible implementations,

[0014] The main body includes a connecting piece arranged vertically and connected to the clamping part, and an end head connected to the connecting piece and arranged obliquely; the through hole 1 is arranged on the connecting piece and one end passes through the end head; the end head has a wedge-shaped structure, and its large end is connected to the connecting piece; the through hole 2 and the lead limiting groove are respectively arranged on the end head, and the through hole 2 is located above the lead limiting groove.

[0015] In some possible implementations,

[0016] The second through hole is inclined from the outside of the wire clamp to the side close to the chopper and smoothly transitions to the lead limit groove.

[0017] In some possible implementations,

[0018] The angle formed by the axis of the second through hole and the horizontal plane is 30° to 80°, that is, a=30° to 80°.

[0019] In some possible implementations,

[0020] The cross section of the lead wire limiting groove is a U-shaped structure or a rectangular structure, and the opening thereof is arranged on a side close to the chopping knife.

[0021] In some possible implementations,

[0022] The depth of the lead limiting groove is E; the thickness of the bonding lead is D, the opening size is F, the width of the second through hole is A, and the length of the second through hole is H, wherein E=0.7D, F=A=1.2D, and H=10A.

[0023] In some possible implementations,

[0024] The distance between the plane where the top end of the body is located and the plane where the top surface of the cleaver is located is e, where e=0.01-0.1 mm.

[0025] In some possible implementations,

[0026] The splitting tool is made of any one of cemented carbide, metal ceramic or diamond, and includes a main rod and an end portion connected to one end of the main rod and used in conjunction with the end head. The end portion is a tetrahedral structure, and the angle formed by its outer surface and the horizontal plane is 40° to 70°.

[0027] on the other hand:

[0028] A method for using a wedge-shaped bonding structure comprises the following steps:

[0029] Step S1: Install the wire clamp on the wire clamp motor thrust rod of the bonding machine through the clamping part, and install the rake on the amplitude rod of the bonding machine;

[0030] Step S2: Align the lead limit groove with the center of the splitter, adjust the distance between the top of the wire clamp and the bonding end surface of the top of the splitter, and tighten;

[0031] Step S3: setting the distal and proximal stop points of the bonding machine clamp according to the diameter of the bonding wire to ensure that the clamp and the wrench cooperate with each other to clamp the bonding wire and the bonding wire will not slip out of the wire limiting groove;

[0032] Step S4: setting the wire clamp to an open state, inserting the bonding wire from the first through hole, and then passing through the second through hole and the wire limiting groove in sequence;

[0033] Step S5: After the parameters are adjusted, the wire clamp is adjusted to a closed state to complete the bonding.

[0034] Compared with the prior art, the present invention has the following beneficial effects:

[0035] The present invention arranges lead vias and auxiliary structures on the wire clamp, which reduces the difficulty of wedge cutter processing, expands the range of wedge cutter material selection, extends the service life of the wedge cutter, and solves the problems of silicon material adhesion and powder particle drop on the wedge cutter, resulting in poor bonding stability and difficult bonding parameter normalization management.

[0036] The invention has a simple structure and strong practicability. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 Schematic diagram of the structure of the centerline clamp of the present invention;

[0038] Figure 2 for Figure 1 Enlarged view of point A in the middle;

[0039] Figure 3 It is a front view of the centerline clamp of the present invention;

[0040] Figure 4 for Figure 3 Enlarged view of point D in the middle;

[0041] Figure 5 It is a rear view of the centerline clamp of the present invention;

[0042] Figure 6 Schematic diagram of the cross-sectional structure of the centerline clamp and the splitting knife after being combined in the present invention;

[0043] Figure 7 for Figure 6 Enlarged view of point B in the middle;

[0044] Figure 8 A cross-sectional view of the present invention when in use;

[0045] Figure 9 for Figure 8 Enlarged view of point C in the middle;

[0046] Figure 10 The relative position relationship between the wire clamp and the riving knife when the wire clamp and the riving knife are closed in the present invention;

[0047] Figure 11 The relative position relationship between the wire clamp and the riving knife when the wire clamp and the riving knife are opened in the present invention;

[0048] Among them: 1. Chopping knife; 2. Wire clamp; 21. Clamping part; 22. Connector; 23. Terminal; 3. Second through hole; 4. Lead limit groove; 5. First through hole; 6. Bonding lead; 7. Near stop point; 8. Far stop point. DETAILED DESCRIPTION

[0049] In this application, unless otherwise specified or limited, terms such as "mounted," "connected," "connect," and "fixed" should be interpreted broadly. For example, they can refer to fixed connections, removable connections, or integration; they can refer to direct connections or indirect connections through an intermediary; they can refer to internal communication between two components or interactions between two components. The terms "first," "second," and similar terms mentioned in this application do not denote any order, quantity, or importance; they are simply used to distinguish between different components. Similarly, terms such as "one" or "a" do not indicate a quantitative limitation; rather, they indicate the presence of at least one. In the implementation of this application, "and / or" describes an association relationship between associated objects, indicating that three possible relationships exist. For example, "A and / or B" can mean: A exists alone, A and B exist simultaneously, or B exists alone. In the description of the embodiments of this application, unless otherwise specified, "plurality" means two or more. For example, "plurality" refers to two or more positioning posts. Those skilled in the art will understand the specific meanings of these terms in this application based on the specific circumstances.

[0050] The present invention is described in detail below.

[0051] like Figures 1-11 As shown:

[0052] on the one hand:

[0053] The present invention discloses a wedge-shaped bonding structure for bonding a bonding wire 6; it comprises a wedge 1 and a wire clamp 2 used in conjunction with the wedge 1; the wire clamp 2 comprises a clamping portion 21 and a body connected to the clamping portion 21;

[0054] The main body is provided with a lead through hole and a lead limiting groove 4 which is connected with the lead through hole and is provided close to one side of the cleaver 1 .

[0055] The present invention guides the bonding lead 6 to the lead limiting groove 4 through the lead via hole, and then conveys the bonding lead 6 to the bonding end surface of the wrecking knife 1 after passing through the lead limiting groove 4. The lead limiting groove 4 effectively limits the swing of the bonding lead 6 during the bonding process, thereby ensuring the bonding accuracy.

[0056] In the present invention, the lead vias originally provided on the chopper 1 in the prior art are transferred to the wire clamp 2, and the chopper 1 only processes the welding end face and the bonding end face. This arrangement greatly optimizes and simplifies the structure of the chopper 1, reduces the difficulty and cost of processing the chopper 1, and after the bonding end face and the welding end face are scrapped, only the chopper 1 needs to be replaced, and the wire clamp 2 can be used for a long time.

[0057] At the same time, since structures such as lead vias are no longer processed on the chopper 1, more high-hardness materials that are difficult to finely process can be used to process the chopper 1, making the range of processing materials of the chopper 1 wider.

[0058] In some possible implementations, in order to effectively ensure the delivery of the bonding wire 6 and to meet the bonding requirements during bonding;

[0059] The lead via includes a vertically arranged through hole 1 5 and an inclined through hole 2 3; one end of the through hole 2 3 away from the through hole 1 5 is connected to the lead limiting groove 4; the axes of the through hole 1 5, the through hole 2 3 and the lead limiting groove 4 are on the same plane.

[0060] In some possible implementations, in order to effectively realize the processing of the lead via on the wire clamp 2 and enable the wire clamp 2 to effectively position and restrict the bonding wire 6 to prevent the bonding wire 6 from moving during use;

[0061] The main body includes a connecting piece 22 arranged vertically and connected to the clamping part 21, and a connecting piece 23 connected to the connecting piece 22 and arranged obliquely; the 23 is a wedge-shaped structure, and its large end is connected to the connecting piece 22; the through hole 1 5 is arranged on the connecting piece 22 and one end passes through 23; the through hole 2 3 and the lead limiting groove 4 are respectively arranged on 23, and the through hole 2 3 is located above the lead limiting groove 4.

[0062] In some possible implementations, in order to effectively prevent the bonding wire 6 from being scratched during transportation;

[0063] The second through hole 3 is inclined from the outside of the wire clamp 2 to the side close to the wrench 1 and smoothly transitions to the lead limiting groove 4;

[0064] Preferably, both ends of the through hole 1 5 and the end faces of the lead limiting groove 4 are chamfered.

[0065] In some possible implementations, in order to enable the bonding wire 6 conveyed through the through hole 1 5 to effectively enter the lead limiting groove 4 under the guidance of the through hole 2 3 and to ensure that the bonding wire 6 is as straight as possible during the conveying process;

[0066] The angle formed by the axis of the second through hole 3 and the horizontal plane is 30° to 80°, that is, a=30° to 80°.

[0067] In some possible implementations, the bonding wire 6 is generally a gold wire or a gold ribbon. In order to effectively implement bonding using the gold wire or the gold ribbon;

[0068] The cross section of the lead wire limiting groove 4 is U-shaped or rectangular, and its opening is arranged on a side close to the riving knife 1 .

[0069] When the bonding wire 6 is a gold wire, the cross section of the gold wire is circular. In this case, the cross section of the lead limiting groove 4 is a U-shaped structure, and the side close to the wrench 1 will pass through the opening of the lead limiting groove 4.

[0070] When the bonding wire 6 is a gold ribbon, the cross-section of the gold ribbon is a rectangular structure. At this time, the cross-section of the lead limiting groove 4 is a rectangular structure. The gold ribbon will be installed in the lead limiting groove 4 of the rectangular structure, and its side close to the cleaver 1 will pass through the opening of the lead limiting groove 4.

[0071] In some possible embodiments, in order to effectively ensure that the wire clamp 2 and the wrench 1 can effectively clamp the bonding wire 6 during bonding to prevent it from moving and affecting the bonding accuracy; the depth of the wire limiting groove 4 is E; the thickness of the bonding wire 6 is D, and the opening size is F, F = 1.2D, E = 0.7D;

[0072] The width of the second through hole 3 is A, and the length of the second through hole 3 is H, wherein E=0.7D, F=A=1.2D, and H=10A. By setting the second through hole 3 to have a large aspect ratio, the straightness of the bonding wire 6 is further ensured.

[0073] In some possible implementations, in order to effectively avoid the influence of the top of the wire clamp 2 on the bonding during bonding, while effectively ensuring that the wire clamp 2 and the wrench 1 are fixed to the bonding wire 6;

[0074] The distance between the plane where the top end of the body is located and the plane where the top surface of the riving knife 1 is located is e, where e=0.01-0.1 mm.

[0075] The top end of the body refers to the end of the head 23 away from the clamping portion 21; the top surface of the riving knife 1 refers to the side of the end away from the main rod, that is, the bonding end surface.

[0076] In some possible implementations,

[0077] The splitting tool 1 is made of any one of cemented carbide, metal ceramic or diamond, and includes a main rod and an end portion connected to one end of the main rod and used in conjunction with the end head 23. The end portion has a gradually decreasing tetrahedral structure, and the angle formed by its outer side surface with the horizontal plane is 40° to 70°, that is, b = 40° to 70°.

[0078] Preferably, the inclination angle between the end 23 and the connecting member 22 is consistent with the inclination angle between the end and the main rod.

[0079] Preferably, the center of the splitting knife 1 is a hollow structure or a solid structure. When it is a hollow structure, the bonding wire 6 is fed from the hollow hole. When it is a solid structure, the bonding wire 6 is fed from the rear cutting part. The structure of the splitting knife 1 is not described in detail here.

[0080] Preferably, the welding end face of the splitting knife 1 is rectangular or square, and the size of a single side of the end face is 0.04 to 1 mm.

[0081] Compared to conventional wedges 1, the present invention eliminates the structure for feeding bonding wires 6, allowing it to process a wider range of materials, such as tungsten carbide, titanium carbide, cermets, zirconium oxide, aluminum oxide, diamond, ruby, ruby-rich oilstone, and sapphire. By using materials such as ceramics and diamond, the present invention effectively addresses the issues of poor bonding stability and difficulty in managing standardized bonding parameters caused by silicon adhesion and powder particle dropout.

[0082] on the other hand:

[0083] A method for using a wedge-shaped bonding structure comprises the following steps:

[0084] Step S1: Install the wire clamp 2 on the wire clamp 2 motor thrust rod of the bonding machine through the clamping portion 21, and install the riving knife 1 on the horn of the bonding machine;

[0085] Step S2: Align the lead limiting groove 4 with the center of the splitting knife 1, adjust the distance between the top of the wire clamp 2 and the bonding end surface of the top of the splitting knife 1, and tighten;

[0086] Step S3: setting the distal and proximal stop points 7 of the bonding machine clamp 2 according to the diameter of the bonding wire 6 to ensure that the clamp 2 and the wrench 1 cooperate with each other to clamp the bonding wire 6 and the bonding wire 6 will not slip out of the wire limiting groove 4;

[0087] Step S4: setting the wire clamp 2 to an open state, inserting the bonding wire 6 from the through hole 1 5, and then passing through the through hole 2 3 and the wire limiting groove 4 in sequence;

[0088] Step S5: Set the bonding parameters of the bonding machine, such as bonding pressure, time, power, and arc, and then perform a bonding test on the combined structure. After adjusting the structure and parameters back and forth, the bonding achieves good results, and the implementation process ends.

[0089] Example 1;

[0090] In this embodiment, a gold wire with a diameter of 0.025 mm is used as the bonding wire 6;

[0091] Wire clamp 2 processing:

[0092] TC4 titanium alloy is used to process the wire clamp 2. First, the overall shape of the wire clamp 2 is processed, and the through hole 5 is processed at the same time.

[0093] After calculation, it can be concluded that the width of the through hole 3 is 0.03mm and the length is 0.3mm; the depth of the lead limiting groove 4 is 0.017mm;

[0094] When processing the lead limiting groove 4 , the wire clamp 2 adopts a U-shaped structure with a depth of 0.017 mm. The head of the lead limiting groove 4 is then chamfered with a chamfer radius of 0.025 mm of the lead diameter.

[0095] Since the through hole 2 3 is deeper than the lead limiting groove 4, when chamfering the lead limiting groove 4, the chamfer of the through hole 2 3 is first processed and formed with a tool; then the lead via is cut out using a laser processing process; after the wire clamp 2 is fine-tuned, the wire clamp 2 is processed.

[0096] Riveting knife 1 processing:

[0097] A zirconia ceramic cylinder is selected as the material of the splitter 1, and its diameter is 1.58 mm;

[0098] Use 600 mesh diamond sand grinding disc to perform rough grinding to obtain preliminary outline dimensions.

[0099] Use a 1200 mesh diamond sand grinding disc for fine grinding to process the bonding end surface to 0.05*0.08 mm.

[0100] The two edges of the pad in the wire bonding direction are chamfered, with a front chamfer radius of 0.013 mm and a rear chamfer radius of 0.025 mm.

[0101] The middle groove of the top is processed by laser;

[0102] Combination of riving knife 1 and wire clamp 2:

[0103] Install the wire clamp 2 on the wire clamp 2 motor thrust rod of the bonder, roughly position according to the length of the cleaver 1, do not tighten, tighten to the wire clamp 2 does not fall, and then fine-tune.

[0104] Install the cleaver 1 on the wedge-shaped bonder's amplitude rod, the upper part of the cleaver 1 is flush with the upper part of the amplitude rod, and the tightening torque is 20-25 cN / m.

[0105] Set the position of the wire clamp 2 of the bonder to the open state, align the lead limiting groove of the wire clamp 2 with the center of the cleaver 1, adjust the distance between the top end of the wire clamp 2 and the bonding end face of the cleaver 1 to about 0.05 mm, and then tighten the two screws back and forth, with a torque of about 40-50 cN / m.

[0106] Set the far stop point 8 and the near stop point 7 of the wire clamp 2 according to the diameter of the bonding lead 6, the bonding lead 6 used this time has a diameter of 0.025 mm, after adjustment, the near stop point 7 is 0.45 mm, and the far stop point 8 is 0.48 mm, so that the lead can be clamped and the lead will not slip out of the limiting groove.

[0107] The near stop point 7 is the closest distance between the wire clamp 2 and the cleaver 1 after adjustment, and the far stop point 8 is the farthest distance between the wire clamp 2 and the cleaver 1 after adjustment;

[0108] Set the wire clamp 2 to the open state, pass the bonding lead 6 through the through hole one 5, then pass it out from the through hole two 3, and into the lead limiting groove 4; after assembling in the above manner, the combination accuracy of the cleaver 1 and the wire clamp 2 is 0.01 mm;

[0109] Set the bonding pressure, time, power, and arc parameters of the bonder, and complete the bonding test of the combined structure.

[0110] After adjusting the structure and parameters back and forth, the bonding achieves good results, and the implementation process is completed.

[0111] After a period of actual application, the welding effect of the present application is good, and the tensile value of the bonding lead 6 is greater than 7 grams.

[0112] The present application is not limited to the foregoing specific embodiments. The present application extends to any new feature or any new combination disclosed in this specification, and any new method or process step or any new combination disclosed.

Claims

1. A method for using a wedge-shaped bonding structure, characterized in that: A wedge-shaped bonding structure for wire bonding, characterized in that it comprises a wedge and a wire clamp used in conjunction with the wedge; the wire clamp comprises a clamping portion and a body connected to the clamping portion; the body is provided with a lead through hole and a lead retaining groove connected to the lead through hole and disposed near the wedge; the lead through hole comprises a vertically arranged through hole 1 and an inclined through hole 2; an end of the through hole 2, remote from the through hole 1, is connected to the lead retaining groove; the axes of the through hole 1, the through hole 2, and the lead retaining groove are in the same plane; The specific steps include: Step S1: Install the wire clamp on the wire clamp motor thrust rod of the bonding machine through the clamping part, and install the rake on the amplitude rod of the bonding machine; Step S2: Align the lead limit groove with the center of the splitter, adjust the distance between the top of the wire clamp and the bonding end surface of the top of the splitter, and tighten; Step S3: setting the distal and proximal stop points of the bonding machine clamp according to the diameter of the bonding wire to ensure that the clamp and the wrench cooperate with each other to clamp the bonding wire and the bonding wire will not slip out of the wire limiting groove; Step S4: setting the wire clamp to an open state, inserting the bonding wire from the first through hole, and then passing through the second through hole and the wire limiting groove in sequence; Step S5: After the parameters are adjusted, the wire clamp is adjusted to a closed state to complete the bonding.

2. The method for using a wedge-shaped bonding structure according to claim 1, characterized in that: The body includes a connecting piece arranged vertically and connected to the clamping portion, and an end head connected to the connecting piece and arranged obliquely; the end head is a wedge-shaped structure, and its large end is connected to the connecting piece; The first through hole is arranged on the connecting piece and one end thereof passes through the terminal; the second through hole and the lead limiting groove are respectively arranged on the terminal and the second through hole is located above the lead limiting groove.

3. The method for using a wedge-shaped bonding structure according to claim 1, wherein: The second through hole is inclined from the outer side of the wire clamp to the side close to the chopper and smoothly transitions to the lead limiting groove.

4. The method for using a wedge-shaped bonding structure according to claim 1, wherein: The angle formed by the axis of the second through hole and the horizontal plane is 30° to 80°.

5. The method for using a wedge-shaped bonding structure according to claim 1, wherein: The cross section of the lead wire limiting groove is a U-shaped structure or a rectangular structure, and the opening thereof is arranged on a side close to the chopping knife.

6. The method for using a wedge-shaped bonding structure according to claim 5, characterized in that: The depth of the lead limiting groove is E; the thickness of the bonding lead is D, the opening size is F, the width of the second through hole is A, and the length of the second through hole is H, wherein E=0.7D, F=A=1.2D, and H=10A.

7. The method for using a wedge-shaped bonding structure according to claim 1, wherein: The distance between the plane where the top of the body is located and the plane where the top surface of the splitting knife is located is e, where e=0.01-0.1 mm.

8. The method for using a wedge-shaped bonding structure according to any one of claims 1 to 7, characterized in that: The splitting tool is made of any one of cemented carbide, metal ceramic or diamond, and includes a main rod and an end portion connected to one end of the main rod and used in conjunction with the end head. The end portion is a tetrahedral structure, and the angle formed by its outer surface and the horizontal plane is 40° to 70°.

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