Cutter, mold and cutting device of lead frame

Abstract

The utility model discloses a cutter, a die and a cutting device of a lead frame, and the cutting device comprises a first die which is used for bearing the lead frame; the second mold is provided with one or more cutters, and the cutters are used for cutting the lead frame; wherein the cutter comprises a cutter main body and a cutter head arranged at the front end of the cutter main body, and the cross section of the cutter head is trapezoidal. According to the invention, the cut single product has double pins or multiple pins to support the packaging body during separation, so that the stability of the product is improved, and the unstable phenomena such as inclination and falling off of the product due to insufficient support in the process of automatically feeding the lead frame are avoided.

Description

Technical Field

[0001] This application relates to the field of semiconductor technology, and more specifically to a cutting tool. Background Technology

[0002] The leadframe is the chip carrier of an integrated circuit, serving to support the chip and connect it to external circuitry during the packaging process. A leadframe without tie-bar support is a special type of leadframe structure that lacks traditional tie-bar components.

[0003] In related technologies, the cutting tool used in leadframe cutting operations has a square cutting head, meaning its cross-section is square. When this tool is used to cut leadframes without tie-bar support, the cut individual products are separated with only a single lead supporting the package.

[0004] During the automatic feeding lead-frame process, because each product is separated by only a single pin to support the package, the product is very prone to tilting, and in severe cases, it may even fall off. Utility Model Content

[0005] The utility model description section introduces a series of simplified concepts, which will be further explained in detail in the detailed description section. This utility model description section is not intended to limit the key features and essential technical features of the claimed technical solution, nor is it intended to determine the scope of protection of the claimed technical solution.

[0006] To address the existing problems, this application provides a cutting device for a lead frame, the cutting device comprising:

[0007] The first mold is used to support the lead frame;

[0008] A second mold is provided with one or more cutting tools, which are used to cut the lead frame;

[0009] The cutting tool includes a cutting tool body and a cutting head disposed at the front end of the cutting tool body, wherein the cutting head has a trapezoidal cross-section.

[0010] In some embodiments of this application, the cutting edge of the blade is a beveled structure.

[0011] In some embodiments of this application, the angle between the inclined structure and the horizontal plane is 3° to 7°.

[0012] In some embodiments of this application, the first mold is provided with grooves that are the same number as the number of cutting tools, and the shape of the grooves matches the shape of the cutting tools.

[0013] In some embodiments of this application, the fitting gap between the cutting tool and the groove is 7% to 10% of the thickness of the lead frame.

[0014] In some embodiments of this application, a stripper plate disposed on the second mold is also included, wherein the clearance between the stripper plate and the cutting tool is 3µm to 5µm.

[0015] In some embodiments of this application, the lead frame includes a lead frame without connecting rib support.

[0016] According to another aspect of this application, a cutting tool is provided for cutting a lead frame, the cutting tool comprising:

[0017] Tool body;

[0018] The cutting head is located at the front end of the main body of the cutting tool, and the cross-section of the cutting head is trapezoidal.

[0019] According to another aspect of this application, a mold is provided having a groove, the shape of which matches the shape of the cutting tool, the cutting tool being inserted into the groove.

[0020] According to the cutting device of the cutting tool, mold and lead frame according to the embodiments of this application, by constructing the cross-section of the cutting tool head as a trapezoid, the single product after cutting has two or more pins supporting the package when separated, thereby increasing the stability of the product and avoiding unstable phenomena such as tilting and falling off that may occur due to insufficient support during the automatic feeding of lead frame. Attached Figure Description

[0021] The following drawings, which are incorporated herein by reference and are used to understand this application, illustrate embodiments of the invention and their descriptions to explain the principles of the invention.

[0022] Figure 1 A schematic diagram of the upper template and the cutting tool mounted on it is shown in the related art.

[0023] Figure 2 A schematic diagram of the structure of a second template and the cutting tool disposed thereon, according to an embodiment of this application, is shown.

[0024] Figure 3A A front view of a cutting tool according to an embodiment of this application is shown.

[0025] Figure 3BA top view of a cutting tool according to one embodiment of this application is shown.

[0026] Figure 3C A side view of a cutting tool according to one embodiment of this application is shown.

[0027] Figure 4A The front view of a first template according to an embodiment of this application is shown.

[0028] Figure 4B A top view of a first template according to an embodiment of this application is shown. Detailed Implementation

[0029] The following description provides numerous specific details to offer a more thorough understanding of this application. However, it will be apparent to those skilled in the art that this application can be practiced without one or more of these details. In other instances, certain technical features well-known in the art have not been described to avoid confusion with this application.

[0030] It should be understood that this application can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, providing these embodiments will make the disclosure thorough and complete, and will fully convey the scope of this application to those skilled in the art. In the drawings, for clarity, the dimensions and relative dimensions of layers and regions may be exaggerated. The same reference numerals denote the same elements throughout.

[0031] It should be understood that when an element or layer is referred to as "on," "adjacent to," "connected to," or "coupled to" other elements or layers, it may be directly on, adjacent to, connected to, or coupled to other elements or layers, or there may be intervening elements or layers. Conversely, when an element is referred to as "directly on," "directly adjacent to," "directly connected to," or "directly coupled to" other elements or layers, there are no intervening elements or layers. It should be understood that although the terms first, second, third, etc., may be used to describe various elements, components, areas, layers, and / or portions, these elements, components, areas, layers, and / or portions should not be limited by these terms. These terms are only used to distinguish one element, component, area, layer, or portion from another element, component, area, layer, or portion. Therefore, without departing from the teachings of this application, the first element, component, area, layer, or portion discussed below may be referred to as the second element, component, area, layer, or portion.

[0032] Spatial relation terms such as “below,” “under,” “below,” “under,” “above,” “above,” etc., are used herein for convenience of description to describe the relationship between one element or feature shown in the figure and other elements or features. It should be understood that, in addition to the orientation shown in the figure, spatial relation terms are intended to also include different orientations of the device in use and operation. For example, if the device in the figure is flipped, then the element or feature described as “below” or “under” the other element or feature will be oriented “above” the other element or feature. Therefore, the exemplary terms “below” and “under” can include both upper and lower orientations. The device may be otherwise oriented (rotated 90 degrees or otherwise) and the spatial descriptive terms used herein will be interpreted accordingly.

[0033] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of this application. When used herein, the singular forms “a,” “an,” and “the” are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “comprising” and / or “including,” when used in this specification, identify the presence of the stated features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups. When used herein, the term “and / or” includes any and all combinations of the associated listed items.

[0034] In related technologies, during the cutting operation of the lead frame, such as Figure 1 As shown, the blade 121 of the cutter 120 used on the upper template 110 of the cutting device has a square structure, that is, its cross-section is square. When the cutter 120 is used to cut a lead frame without tie-bar support, the cut single product is separated with only a single lead to support the package.

[0035] During the automatic feeding lead-frame process, because each product is separated by only a single pin to support the package, the product is very prone to tilting, and in severe cases, it may even fall off.

[0036] The aforementioned issues further exacerbated subsequent problems. Due to product tilting or detachment, abnormal forces were exerted on the cutting tool 120 during final separation. These abnormal forces easily caused the cutting tool 120 to break, and the product itself also cracked due to the abnormal stress, thus increasing the cost of replacing the cutting tool 120 and reducing product yield.

[0037] Additionally, on the cut surface of the product, of the eight pins, seven are cut from the heat sink toward the package body. The remaining pin, as a connecting rib, is cut in the opposite direction to the other seven pins, resulting in burrs on the cut surface pointing in the opposite direction, which can easily obstruct the grooves on the lower template.

[0038] To fully understand this application, detailed steps and structures will be presented in the following description to illustrate the technical solutions proposed in this application. Preferred embodiments of this application are described in detail below; however, in addition to these detailed descriptions, this application may have other implementation methods.

[0039] The following is for reference. Figure 2 , Figures 3A-3C and Figures 4A-4B This application describes a cutting apparatus for a lead frame according to one embodiment. The cutting apparatus includes: a first mold 230 for supporting the lead frame; a second mold 210, on which one or more cutters 220 are disposed, the cutters 220 being used to cut the lead frame; wherein, the cutter 220 includes a cutter body 221 and a cutter head 222 disposed at the front end of the cutter body 221, the cutter head 222 having a trapezoidal cross-section.

[0040] In some embodiments, the lead frame supported on the first mold 230 may be a lead frame without connecting ribs or any other suitable lead frame, without limitation.

[0041] Taking the lead frame without connecting ribs supported on the first mold 230 as an example, when the lead frame without connecting ribs is cut by the cutter 220, since the cutter head 222 of the cutter 220 has a trapezoidal structure, that is, its cross-section is trapezoidal, more pins can be connected to the package after cutting. This allows the cut single product to have double lead or multiple lead to support the package when separated, thereby increasing the stability of the product and avoiding unstable phenomena such as tilting or falling off that may occur due to insufficient support during the automatic feeding of lead frames.

[0042] Furthermore, thanks to the significant improvement in product stability, abnormal forces applied to the tool 220 can be effectively avoided during the final separation operation. This prevents the tool 220 from breaking and avoids cracking due to uneven stress, thereby significantly reducing the frequency and cost of tool 220 replacement and significantly improving product yield.

[0043] In some embodiments, the cutting edge of the cutter head 222 has a beveled structure. By constructing the cutting edge of the cutter head 222 as a beveled structure, when the cutter 220 cuts the lead frame, there is a certain angle of attack between the cutting edge and the lead frame.

[0044] In this embodiment, by changing the angle between the bevel structure of the cutting edge and the horizontal plane, the angle of attack between the cutting edge and the lead frame can be changed, thereby affecting the ease and quality of cutting the lead frame by the cutting tool 220.

[0045] For example, the angle between the inclined structure and the horizontal plane is 3° to 7°, such as 3°, 4°, 5°, 6°, 7° or any other suitable angle, without limitation.

[0046] As mentioned above, by limiting the angle between the inclined structure and the horizontal plane, the cutting angle between the cutting edge and the lead frame can be optimized. The optimized cutting angle allows the tool 220 to be subjected to force more evenly when cutting the lead frame, reducing local wear and improving the durability of the tool 220.

[0047] Furthermore, the optimized cutting angle reduces vibration and deformation during the cutting process, resulting in neater and smoother cut edges, and improving dimensional accuracy and surface finish. By improving the surface finish of the cut surface, burrs can be avoided from blocking the groove 240 on the first mold 230 described below.

[0048] In some embodiments, a stripper plate disposed on the second mold 210 is also included, and the clearance between the stripper plate and the cutter 220 is 3µm to 5µm.

[0049] The stripper plate's function is to separate or detach the cut product from the cutting tool 220 during the cutting process. Specifically, during the cutting operation, when the cutting tool 220 cuts into the lead frame, the lead frame will deform due to the cutting force and may tightly adhere to the cutting tool 220. The stripper plate then comes into play; by applying a certain counterforce, it pushes the cut product away from the cutting edge of the cutting tool 220, allowing the cut product to detach smoothly from the cutting tool 220.

[0050] By setting a 3µm to 5µm clearance between the stripper plate and the cutter 220, the stripper plate can more precisely guide the cutter 220. When the cutter 220 performs a cutting operation, the smaller clearance effectively restricts the lateral displacement of the cutter 220, ensuring that the cutter 220 can only cut along a predetermined precise path, thereby greatly improving cutting accuracy and enabling more accurate control of cutting dimensions. After the cutter 220 cuts the lead frame material, the 3µm to 5µm clearance ensures that the stripper plate separates the material from the cutter 220 at the appropriate time and with the appropriate force. A clearance that is too large may prevent the stripper plate from effectively contacting the material for separation, while a clearance that is too small may result in excessive friction between the material and the cutter 220, hindering smooth material separation.

[0051] In some embodiments, such as Figures 4A-4B As shown, the first mold 230 has grooves 240 in the same number as the cutting tools 220. When one or more cutting tools 220 are used to cut the lead frame, the position of each cutting tool 220 on the second mold 210 corresponds to the corresponding groove 240 on the first mold 230, so that after the cutting is completed, each cutting tool 220 extends into the corresponding groove 240.

[0052] In some embodiments, the shape of the groove 240 matches the shape of the cutting tool 220. The groove 240 on the first mold 230 may include a first groove 240 portion and a second groove 240 portion connected from bottom to top. The shape of the first groove 240 portion matches the shape of the cutting head 222 of the cutting tool 220, and the shape of the second groove 240 portion matches the shape of the cutting tool body 221 of the cutting tool 220.

[0053] By matching the shape of the groove 240 with the shape of the cutter 220, when the cutter 220 cuts the lead frame, the shape of the groove 240 ensures that the cutter 220 cuts along a precise predetermined trajectory, thereby avoiding deviations in the cutting path and improving the accuracy of the cutting dimensions and the quality of the cut surface. Furthermore, the matching shape of the groove 240 with the cutter 220 ensures that the cutter 220 is constrained within the groove 240 wall, reducing vibration during the cutting process. A stable cutter 220 state helps to apply cutting force evenly, avoiding lead frame deformation or uneven cut surfaces caused by uneven force, and extending the service life of the cutter 220, thus reducing the frequency and cost of cutter 220 replacement.

[0054] In some embodiments, there may be a certain fitting gap between the cutter 220 and the groove 240. The size of the fitting gap can be set according to the actual situation. For example, the fitting gap can be 7% to 10% of the thickness of the lead frame, such as 7% of the thickness of the lead frame, 8% of the thickness of the lead frame, 9% of the thickness of the lead frame, 10% of the thickness of the lead frame, or any other suitable proportion of the thickness of the lead frame. There is no limitation on this.

[0055] By setting a certain clearance between the tool 220 and the groove 240, the tool 220 can smoothly enter and exit the groove 240. If the clearance is too small, the tool 220 may interfere with the wall of the groove 240 during entry and exit due to minor dimensional deviations, thermal expansion and contraction of the material, or vibration during processing, causing the tool 220 to jam or the wall of the groove 240 to be damaged. A clearance of 7% to 10% of the lead frame thickness can well accommodate this variation and ensure that the tool 220 can work smoothly.

[0056] Moreover, during the cutting process, chips and potential impurities are generated, and the 7% to 10% lead frame thickness clearance provides storage space for these chips and impurities.

[0057] In addition, the cutting tool 220 will generate impact and vibration during the cutting process. The fitting gap of 7% to 10% of the lead frame thickness can play a buffering role, absorbing part of the impact and vibration and preventing the cutting tool 220 and groove 240 from being damaged by strong impact. At the same time, it also helps to improve the stability and accuracy of cutting.

[0058] In some embodiments, a drive component is also included, connected to the second mold 210, for driving the second mold 210 toward the first mold 230 so that the cutter 220 of the second mold 210 cuts the lead frame on the first mold 230.

[0059] Specifically, the first mold 230 can be a lower mold, and the second mold 210 can be an upper mold. The second mold 210 is located above the first mold 230. When it is necessary to cut the lead frame on the first mold 230, the second mold 210 is driven to move toward the first mold 230 by the drive component, so that the cutter 220 of the second mold 210 cuts the lead frame on the first mold 230.

[0060]

[0061] The table above illustrates the differences between the square-structured cutter head in related technologies and the improved trapezoidal-structured cutter head of this application in terms of material drop alarm frequency, cutter breakage frequency, mean time between failures (MTBF), and equipment replacement cost. As can be seen from the table, the improved trapezoidal-structured cutter head of this application reduces the material drop alarm frequency from 1 to 3 times per strip to 0, the cutter breakage frequency from 1 to 50 times per strip to 0, increases the MTBF from 135 hours per week to 159 hours per week, and reduces the equipment replacement cost from approximately 3500 RMB per month to 0. The improved trapezoidal-structured cutter head of this application has significant advantages over the square-structured cutter head in related technologies.

[0062] According to another aspect of this application, a cutting tool 220 is provided. The cutting tool 220 is used to cut a lead frame, such as... Figures 3A-3C As shown, the cutting tool 220 includes: a cutting tool body 221; and a cutting head 222, which is disposed at the front end of the cutting tool body 221, and the cross-section of the cutting head 222 is trapezoidal.

[0063] In some embodiments, the lead frame cut by the tool 220 may be a lead frame without connecting rib support or any other suitable lead frame, without limitation.

[0064] Taking the cutting of a lead frame without connecting rib support using a cutting tool 220 as an example, since the cutting head 222 of the cutting tool 220 has a trapezoidal structure, that is, its cross-section is trapezoidal, more pins can be connected to the package after cutting. This allows the cut single product to have double lead or multilead support for the package when separated, thereby increasing the stability of the product and avoiding instability such as tilting or falling off that may occur due to insufficient support during the automatic feeding of lead frames.

[0065] Furthermore, thanks to the significant improvement in product stability, abnormal forces applied to the tool 220 can be effectively avoided during the final separation operation. This prevents the tool 220 from breaking and avoids cracking due to uneven stress, thereby significantly reducing the frequency and cost of tool 220 replacement and significantly improving product yield.

[0066] In some embodiments, the cutting edge of the cutter head 222 has a beveled structure. By constructing the cutting edge of the cutter head 222 as a beveled structure, when the cutter 220 cuts the lead frame, there is a certain angle of attack between the cutting edge and the lead frame.

[0067] In this embodiment, by changing the angle between the bevel structure of the cutting edge and the horizontal plane, the angle of attack between the cutting edge and the lead frame can be changed, thereby affecting the ease and quality of cutting the lead frame by the cutting tool 220.

[0068] For example, the angle between the inclined structure and the horizontal plane is 3° to 7°, such as 3°, 4°, 5°, 6°, 7° or any other suitable angle, without limitation.

[0069] As described above, by limiting the angle between the inclined structure and the horizontal plane, the angle of attack between the cutting edge and the lead frame can be optimized. The optimized angle of attack allows the tool 220 to bear force more evenly when cutting the lead frame, reducing local wear and improving the durability of the tool 220. Moreover, the optimized angle of attack can reduce vibration and deformation during the cutting process, making the cut edge of the product neater and smoother, and improving the dimensional accuracy and surface finish of the cut.

[0070] In some embodiments, such as Figure 2 As shown, the cutting tool 220 can be disposed on the second mold 210, and the second mold 210 can be provided with one or more cutting tools 220. The second mold 210 can be the upper mold.

[0071] For further descriptions of the cutting tool 220, please refer to the description of the cutting tool 220 in the cutting device section above; it will not be repeated here.

[0072] According to another aspect of this application, a mold is provided. The mold may be a first mold 230, such as... Figures 4A-4B As shown, the mold is provided with a groove 240, the shape of which matches the shape of the cutting tool 220 mentioned above.

[0073] The groove 240 on the mold may include a first groove 240 portion and a second groove 240 portion connected from bottom to top. The shape of the first groove 240 portion matches the shape of the cutting head 222 of the tool 220, and the shape of the second groove 240 portion matches the shape of the tool body 221 of the tool 220.

[0074] By matching the shape of the groove 240 with the shape of the cutter 220, when the cutter 220 cuts the lead frame, the shape of the groove 240 ensures that the cutter 220 cuts along a precise predetermined trajectory, thereby avoiding deviations in the cutting path and improving the accuracy of the cutting dimensions and the quality of the cut surface. Furthermore, the matching shape of the groove 240 with the cutter 220 ensures that the cutter 220 is constrained within the groove 240 wall, reducing vibration during the cutting process. A stable cutter 220 state helps to apply cutting force evenly, avoiding lead frame deformation or uneven cut surfaces caused by uneven force, and extending the service life of the cutter 220, thus reducing the frequency and cost of cutter 220 replacement.

[0075] In some embodiments, there may be a certain fitting gap between the cutter 220 and the groove 240. The size of the fitting gap can be set according to the actual situation. For example, the fitting gap can be 7% to 10% of the thickness of the lead frame.

[0076] By setting a certain clearance between the tool 220 and the groove 240, the tool 220 can smoothly enter and exit the groove 240. If the clearance is too small, the tool 220 may interfere with the wall of the groove 240 during entry and exit due to minor dimensional deviations, thermal expansion and contraction of the material, or vibration during processing, causing the tool 220 to jam or the wall of the groove 240 to be damaged. A clearance of 7% to 10% of the lead frame thickness can well accommodate this variation and ensure that the tool 220 can work smoothly.

[0077] Moreover, during the cutting process, chips and potential impurities are generated, and the 7% to 10% lead frame thickness clearance provides storage space for these chips and impurities.

[0078] In addition, the cutting tool 220 will generate impact and vibration during the cutting process. The fitting gap of 7% to 10% of the lead frame thickness can play a buffering role, absorbing part of the impact and vibration and preventing the cutting tool 220 and groove 240 from being damaged by strong impact. At the same time, it also helps to improve the stability and accuracy of cutting.

[0079] For further descriptions of the mold, please refer to the introduction of the first mold 230 in the cutting device section above, which will not be repeated here.

[0080] In summary, the cutting device for the cutting tool, mold, and lead frame according to the embodiments of this application constructs the cross-section of the cutting tool head into a trapezoidal shape, so that the cut single product has two or more pins supporting the package when separated, thereby increasing the stability of the product and avoiding instability such as tilting or falling off that may occur due to insufficient support during the automatic feeding of the lead frame.

[0081] Although exemplary embodiments have been described herein with reference to the accompanying drawings, it should be understood that the above exemplary embodiments are merely illustrative and are not intended to limit the scope of this application. Various changes and modifications can be made therein by those skilled in the art without departing from the scope and spirit of this application. All such changes and modifications are intended to be included within the scope of this application as claimed in the appended claims.

[0082] Similarly, it should be understood that, in order to simplify this application and aid in understanding one or more aspects of the application, various features of this application may sometimes be grouped together in a single embodiment, figure, or description thereof in the description of exemplary embodiments of this application. However, this approach should not be construed as reflecting an intention that the claimed application requires more features than are expressly recited in each claim. Rather, as reflected in the corresponding claims, the point of application is that the corresponding technical problem can be solved with fewer features than all of a single disclosed embodiment. Therefore, the claims following the detailed description are hereby expressly incorporated into that detailed description, wherein each claim itself is a separate embodiment of this application.

[0083] Furthermore, those skilled in the art will understand that although some embodiments described herein include certain features but not others included in other embodiments, combinations of features from different embodiments are intended to be within the scope of this application and form different embodiments. For example, in the claims, any one of the claimed embodiments can be used in any combination.

[0084] It should be noted that the above embodiments are illustrative of this application and not limiting of it, and that those skilled in the art can devise alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses should not be construed as limiting the claims. The use of the words first, second, and third, etc., does not indicate any order. These words can be interpreted as names.

Claims

1. A cutting device for a lead frame, characterized in that, The cutting device includes: The first mold is used to support the lead frame; A second mold is provided with one or more cutting tools, which are used to cut the lead frame; The cutting tool includes a cutting tool body and a cutting head disposed at the front end of the cutting tool body, wherein the cutting head has a trapezoidal cross-section.

2. The lead frame cutting device as described in claim 1, characterized in that, The cutting edge of the blade is a beveled structure.

3. The lead frame cutting device as described in claim 2, characterized in that, The angle between the inclined structure and the horizontal plane is 3° to 7°.

4. The lead frame cutting device as described in claim 1, characterized in that, The first mold has grooves that are the same number as the number of cutting tools, and the shape of the grooves matches the shape of the cutting tools.

5. The lead frame cutting device as described in claim 4, characterized in that, The clearance between the cutting tool and the groove is 7% to 10% of the thickness of the lead frame.

6. The lead frame cutting device as described in claim 1, characterized in that, It also includes a stripper plate disposed in the second mold, wherein the clearance between the stripper plate and the cutting tool is 3µm to 5µm.

7. The lead frame cutting device as described in claim 1, characterized in that, The lead frame includes a lead frame without connecting ribs for support.

8. A cutting tool for cutting a lead frame, characterized in that, The cutting tool includes: Tool body; The cutting head is located at the front end of the main body of the cutting tool, and the cross-section of the cutting head is trapezoidal.

9. A mold, characterized in that, The mold is provided with a groove, the shape of which matches the shape of the cutting tool as described in claim 8, and the cutting tool is used to extend into the groove.

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