A wedge bonding blade having an increased friction surface

Abstract

The utility model discloses a wedge welding cleaver with the surface of increasing friction force, including handle and tool bit, and the tool bit includes V-shaped recess, and the both sides of V-shaped recess have the welding surface, and the welding surface extends outwardly and has the tangent plane, and the both ends of welding surface along the direction of V-shaped recess extend and have the arc connecting surface, and the longitudinal structure perpendicular to the direction of V-shaped recess is arranged on the welding surface. The utility model discloses a longitudinal structure perpendicular to the V-shaped recess of wedge welding cleaver welding surface setting, can effectively increase the friction of welding surface and metal keying silk, avoid the keying silk slippage in the welding process, simultaneously, the longitudinal structure can reduce the direct contact area of welding surface and aluminium wire, reduce the accumulation of aluminium scrap on the welding surface and stick, solve the traditional smooth welding surface aluminium scrap stickiness problem, improve the wedge welding yield, prolong the practical life of cleaver.

Description

Technical Field

[0001] This utility model relates to the field of semiconductor manufacturing technology, specifically to a wedge bonding cutter used in wire bonding processes in semiconductor back-end manufacturing, and more specifically to a wedge bonding cutter with an added longitudinal structure on the bonding surface to improve surface friction. Background Technology

[0002] In the back-end packaging process of semiconductor devices, wire bonding is the core process for achieving electrical connections between the chip and the external leadframe or substrate, and the wedge bonding cutter is one of the key tools in this process. A wedge bonding cutter typically includes a shank for clamping and fixing the wires and a cutting head for guiding and bonding the wires. During bonding, the metal wires (such as gold, copper, or aluminum wires) must pass through the guide along the V-shaped groove and be bonded to the chip pads or leadframe bonding area using pressure, ultrasonic energy, or thermal energy, ultimately completing the electrical connection.

[0003] However, existing wedge welding cutters have some technical defects that affect bonding quality and production yield. Firstly, the welding surface friction is insufficient. The welding surface of existing cutters is mostly a flat plane, while the metal bonding wire needs to be stably clamped along a direction perpendicular to the V-groove (i.e., the direction of bonding pressure application) during welding. A flat welding surface cannot provide sufficient normal friction, causing the metal wire to easily slip laterally under welding pressure and ultrasonic vibration, leading to problems such as weld point misalignment, insufficient bonding strength, and even incomplete welds.

[0004] Secondly, there is poor structural adaptability: although some existing cleavers attempt to increase surface roughness to improve friction, they have not precisely designed the size and shape of the protrusions / grooves. If the structural size is too large, the metal bonding wires will not be able to fully fit with the welding surface, forming point contact instead of surface contact, thus affecting the bonding reliability; if the size is too small, it will not be able to effectively improve friction, and there is still a risk of slippage.

[0005] Therefore, it is necessary to improve the existing wedge welding cutter to solve the above problems. Utility Model Content

[0006] To address this problem, this utility model proposes a wedge welding cutter with a surface that increases friction, comprising a handle and a cutter head. The cutter head includes a V-shaped groove, with welding surfaces on both sides of the V-shaped groove. A flat cutting surface extends outward from the welding surface, and an arc-shaped connecting surface extends from both ends of the welding surface along the direction of the V-shaped groove. A longitudinal structure perpendicular to the direction of the V-shaped groove is provided on the welding surface.

[0007] Furthermore, the longitudinal structure features longitudinal protrusions or longitudinal grooves.

[0008] Furthermore, the vertical structures are arranged at equal intervals.

[0009] Furthermore, the longitudinal structure extends to the arc-shaped connecting surface.

[0010] Furthermore, the width of the longitudinal protrusion is 0.005–0.05 mm, and the height is 0.003–0.03 mm.

[0011] Furthermore, the width of the longitudinal groove is 0.005–0.05 mm, and the depth is 0.003–0.03 mm.

[0012] Furthermore, the cross-section of the longitudinal protrusion is square, trapezoidal, or triangular.

[0013] Furthermore, the cross-section of the longitudinal groove is square, trapezoidal, or triangular.

[0014] Furthermore, the ratio of the longitudinal structural width to the spacing width is 1:1 to 1:3.

[0015] Furthermore, the V-shaped groove has an arc-shaped bottom, and the longitudinal structure is distributed between the welding surface and the flat surface to between the welding surface and the arc-shaped bottom.

[0016] This invention effectively increases the friction between the welding surface and the metal bonding wire by setting a longitudinal structure perpendicular to the V-shaped groove on the welding surface of the wedge welding cutter, preventing the bonding wire from slipping during welding and ensuring welding accuracy. It can maintain the friction effect while avoiding damage to the tiny bonding wire, and the square, trapezoidal, or triangular cross-section can adapt to different welding process requirements. The longitudinal structure extends from between the welding surface and the flat cut surface to between the welding surface and the arc-shaped bottom, and can further extend to the arc-shaped connecting surface, fully covering the key contact area between the bonding wire and the welding surface, further enhancing frictional stability. Simultaneously, the longitudinal structure reduces the direct contact area between the welding surface and the aluminum wire, reducing the accumulation and adhesion of aluminum chips on the welding surface, solving the problem of aluminum chip adhesion on traditional smooth welding surfaces, improving wedge welding yield, and extending the service life of the cutter. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the entire cleaver.

[0018] Figure 2 This is a schematic diagram of the blade head structure of a cleaver according to one embodiment.

[0019] Figure 3 This is a schematic diagram of the structure of the cleaver head in another embodiment.

[0020] Figure 4 This is a schematic diagram showing the longitudinal protrusion extending to the arc-shaped connecting surface in the head of a chopping knife.

[0021] Figure 5 This is a schematic diagram showing the longitudinal groove in the blade head extending to the arc-shaped connecting surface.

[0022] Figure Labels

[0023] 1. Knife handle

[0024] 2. Blade head

[0025] 21V-shaped groove

[0026] 210 curved bottom

[0027] 22 Welding surfaces

[0028] 220 Longitudinal Structure

[0029] 221 Longitudinal protrusion

[0030] 222 Longitudinal groove

[0031] 23 flat sections

[0032] 24 arc-shaped connection surfaces Detailed Implementation

[0033] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0034] In the description of this utility model, "multiple" means two or more, unless otherwise explicitly specified.

[0035] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed," "equipped with," "sleeved / connected," "connected," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0036] Please refer to the following content. Figures 1-5The core improvement of this utility model lies in solving the problem of slippage of metal bonding wire and insufficient friction during traditional wedge welding by setting a specific longitudinal structure on the welding surface of the blade head. Its overall structure includes a handle 1 and a blade head 2, which are preferably integrally formed. The material is tungsten steel, which is a common material in the industry, to take into account both high hardness and wear resistance, and to extend the service life of the wedge. In another optional embodiment, the two can also be connected by threads for easy replacement of the blade head 2 after wear, so as to reduce the cost of use.

[0037] The cutting head 2 is the core working component of the wedge welding tool. Its overall profile is adapted to the "V-shaped clamping-welding" requirements of the wedge welding process. Specifically, it includes a V-shaped groove 21, an arc-shaped bottom 210, a welding surface 22, a flat cutting surface 23, and an arc-shaped connecting surface 24. The V-shaped groove 21 is the main area for receiving and positioning the metal bonding wire. The groove angle is preferably 60°-90°, which is suitable for metal bonding wires with a diameter of 0.1-0.5mm commonly used in the industry, such as aluminum wire, gold wire, and copper wire, to ensure that the bonding wire is stably embedded and does not shift before welding. The arc-shaped bottom 210 serves as the bottom transition structure of the V-shaped groove 21, with a radius preferably of 0.005-0.02 mm. This avoids rigid point contact between the bonding wire and the bottom of the groove, preventing the bonding wire from breaking due to excessive local stress. The welding surface 22 is the inclined working surface on both sides of the V-shaped groove 21, and is also the main area where friction between the bonding wire and the cutting tool is generated. It smoothly transitions with the arc-shaped bottom 210 to avoid stress concentration. The angle between the welding surface on one side and the axis of symmetry of the V-shaped groove is 30°-45°, which matches the groove opening angle. The flat cut surface 23 extends outward from the welding surface 22, with a width of 0.1 mm-0.3 mm and an angle of 120°-150° with the welding surface 22. This avoids interference between the edge of the cutting tool 2 and the substrate to be welded during welding, while also providing structural support for the welding surface 22.

[0038] The arc-shaped connecting surface 24 extends from both ends along the length direction of the welding surface 22 (i.e., the extension direction of the V-shaped groove 21), with an arc length of 0.05-0.1mm and a radius of 0.01-0.05mm. It is used to transition the welding surface 22 and the side of the cutter head 2 to prevent the bonding wire from being scratched by the sharp edge of the cutter head.

[0039] To enhance the friction between the welding surface 22 and the bonding wire, this invention provides multiple longitudinal structures 220 arranged at equal intervals perpendicular to the direction of the V-shaped groove 21 on the welding surface 22. The distribution range covers the connection between the welding surface 22 and the flat cut surface 23 to the transition between the welding surface 22 and the arc-shaped bottom 210. The ratio of the width of the longitudinal structure 220 to the width of the adjacent spacing is 1:2. This ratio can ensure the friction while avoiding the bonding wire being deformed due to excessive density of the longitudinal structure or the friction effect being insufficient due to excessive sparseness, thus balancing practicality and structural stability.

[0040] The following details the vertical structure in two core scenarios: Please refer to [link / reference]. Figure 2In one embodiment, the longitudinal structure 220 consists of longitudinal protrusions 221 distributed on the welding surface 22. The width ranges from 0.005 to 0.05 mm (to accommodate the contact requirements of small bonding wires), and the height ranges from 0.003 to 0.03 mm (too high a height would deform the bonding wires, while too low a height would not effectively increase friction). A preferred width is 0.01 mm to 0.03 mm, and a preferred height is 0.005 mm to 0.02 mm. This parameter range allows the protrusions to form stable line contact with bonding wires with a diameter of 0.1-0.5 mm, increasing the coefficient of friction compared to traditional smooth welding surfaces without damaging the bonding wire surface. Based on a width-to-spacing ratio of 1:2, when the width of the longitudinal protrusion is 0.005 mm, the spacing is 0.01 mm; when the width is 0.05 mm, the spacing is 0.1 mm, meaning the overall spacing is 0.01 mm to 0.1 mm. The longitudinal protrusion cross section can be square, trapezoidal, or triangular. The top edge of the square cross section is preferably rounded with a radius of 0.001mm-0.002mm to avoid scratching the bonding wire and to ensure the contact area. The width ratio of the upper base to the lower base of the trapezoidal cross section is 1:1.5 to enhance the strength of the protrusion structure (prevent wear and breakage after long-term use) and increase the contact area. The apex angle of the triangular cross section is 60°-90°, and the vertex can form point contact with the bonding wire, generating greater contact pressure under the same welding pressure to improve the anti-slip effect.

[0041] Please refer to Figure 3 In another embodiment, the longitudinal structure 220 is a longitudinal groove 222 recessed along the welding surface. Its design logic is consistent with the longitudinal protrusion (increasing friction through the interlocking of the groove and protrusion). The width range is also 0.005–0.05 mm (adapting to the width of the protrusion and the bonding wire), and the depth range is 0.003–0.03 mm. The depth corresponds to the height of the protrusion, avoiding excessive depth leading to dust accumulation affecting welding or insufficient depth resulting in no friction. Considering both process feasibility and friction effect, the preferred width is 0.01 mm–0.03 mm, and the preferred depth is 0.005 mm–0.02 mm. These parameters allow the bonding wire to partially embed into the groove, forming a mating contact and providing an anti-slip effect. It is superior to traditional smooth surfaces and the grooves are easy to clean with conventional compressed air; the spacing derivation is the same as the first case, based on a width-to-spacing ratio of 1:2, with a spacing of 0.01mm to 0.1mm; the longitudinal groove cross-section can also be square, trapezoidal, or triangular. The edges of the square groove opening need to be rounded with a radius of 0.001mm-0.002mm to prevent scratching the bonding wire. The width ratio of the upper base to the lower base of the trapezoidal groove is 1.5:1 to ensure smooth insertion of the bonding wire and avoid the groove bottom being too narrow, which would cause processing difficulties. The apex angle of the triangular groove opening is 60°-90°, and the bottom of the groove needs to retain a flat bottom of 0.001mm-0.002mm to prevent cracks during processing.

[0042] Please refer to Figures 4-5To further enhance friction and prevent the bonding wire from slipping at the end of the V-groove 21 (near the arc-shaped connection surface) during welding, the longitudinal structures in both cases can be further extended to the arc-shaped connection surface 24. The extension range is such that the longitudinal structure extends along the arc length of the arc-shaped connection surface 24, with 1-3 longitudinal structures 220 distributed on the arc-shaped connection surface 24. Excessive extension weakens the structural strength. The width and spacing of the longitudinal structures extending to the arc-shaped connection surface 24 are consistent with those on the welding surface to ensure uniform friction and prevent the bonding wire from shifting due to local friction differences. This extension design expands the friction contact area between the bonding wire and the wedge from the welding surface to the welding surface 22 and part of the arc-shaped connection surface 24, increasing the contact area. This is especially suitable for bonding wires with lower hardness and can effectively prevent them from sliding towards the arc-shaped connection surface under welding pressure.

[0043] This invention solves the problem of insufficient friction in traditional wedges by setting a longitudinal structure with a width-to-spacing ratio of 1:1 to 1:3 on the welding surface of the wedge welding wedge and optimizing the size, cross-sectional shape and distribution range of the longitudinal structure. The above parameters are designed based on the industry's conventional bonding wire specifications and wedge processing technology, and can be directly used in actual production, with significant practicality and industrialization value.

[0044] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed utility model. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. A wedge welding cutter with a surface that increases friction, comprising a shank and a cutting head, characterized in that, The cutter head includes a V-shaped groove with welding surfaces on both sides. A flat cutting surface extends outward from the welding surface, and an arc-shaped connecting surface extends from both ends of the welding surface along the direction of the V-shaped groove. A longitudinal structure perpendicular to the direction of the V-shaped groove is provided on the welding surface.

2. A wedge welding cutter with an increased friction surface according to claim 1, characterized in that, The longitudinal structure has longitudinal protrusions or longitudinal grooves.

3. A wedge welding cutter with an increased friction surface according to claim 1, characterized in that, The longitudinal structures are arranged at equal intervals.

4. A wedge welding cutter with a surface that increases friction as described in claim 1, characterized in that, The longitudinal structure extends further to the arc-shaped connecting surface.

5. A wedge welding cutter with an increased friction surface according to claim 2, characterized in that, The width of the longitudinal protrusion is 0.005–0.05 mm, and the height is 0.003–0.03 mm.

6. A wedge welding cutter with an increased friction surface according to claim 2, characterized in that, The width of the longitudinal groove is 0.005 to 0.05 mm, and the depth is 0.003 to 0.03 mm.

7. A wedge welding cutter with an increased friction surface according to claim 2, characterized in that, The cross-section of the longitudinal protrusion is square, trapezoidal, or triangular.

8. A wedge welding cutter with an increased friction surface according to claim 2, characterized in that, The cross-section of the longitudinal groove is square, trapezoidal, or triangular.

9. A wedge welding cutter with an increased friction surface according to claim 3, characterized in that, The ratio of the longitudinal structure width to the spacing width is between 1:1 and 1:

3.

10. A wedge welding cutter with an increased friction surface according to claim 1, characterized in that, The V-shaped groove has an arc-shaped bottom, and the longitudinal structure is distributed between the welding surface and the flat cut surface to between the welding surface and the arc-shaped bottom.

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