TSSOP20 lead frame and stamping assembly

Abstract

The utility model discloses a TSSOP20 lead frame and a stamping assembly, the TSSOP20 lead frame comprises a rectangular frame and a subunit, the subunit comprises a base island and a pin, the base island sinks in the rectangular frame, the base island is in a quasi-rectangular shape, the corner of the base island has radian, two ends of the base island are provided with first connecting ribs, the other end of each first connecting rib is connected with the rectangular frame, and the pin is connected with the rectangular frame. The pins are arranged on the side edges of the base island, an included angle is formed between the pins and the base island, second connecting ribs are arranged on the pins, and the other ends of the second connecting ribs are connected with the rectangular frame. The stamping assembly comprises an upper die and a lower die, and the upper die and the lower die are matched for stamping to form the TSSOP20 lead frame. The beneficial effects of the utility model are that the corners of the base island are arranged to be arc-shaped, so that the base island can be effectively prevented from being broken; the L-shaped pins lock the four corners of the base island, so that the structural shape of the base island is more stable; and a positioning structure and an adjusting assembly are arranged on the stamping assembly, so that the machined lead frame can be ensured to have a relatively high yield.

Description

Technical Field

[0001] This application relates to the field of lead frame technology, and in particular to a TSSOP20 lead frame and stamping assembly. Background Technology

[0002] The TSSOP20 package is a compact 20-pin package suitable for circuit designs requiring high-density layout. Its low external dimensions and narrow spacing allow for the integration of more functionality within a limited space. This package is commonly used for logic devices, memory, amplifiers, and various other electronic components in integrated circuits.

[0003] The corners of the base islands in traditional lead frames are mostly right angles. During subsequent chemical corrosion, the chemical may deposit at the four corners of the base islands, leading to excessive corrosion and affecting the yield of the lead frames. In addition, the right angles of the base islands may cause stress concentration at the corners during subsequent use, which can easily cause breakage. Therefore, it is necessary to improve the existing base island structure.

[0004] Stamping is a crucial step in lead frame manufacturing. Current technologies mostly utilize stamping plates to directly stamp leads onto the sheet metal. However, the spacing between leads varies across different lead frame models, requiring different stamping dies to be used when the lead spacing changes. This undoubtedly reduces the manufacturing efficiency of lead frames. Furthermore, the lead frame structure is relatively precise; angular errors or excessive stamping force during the stamping process can lower the yield rate. Therefore, a safe and efficient stamping assembly is urgently needed. Utility Model Content

[0005] One objective of this application is to provide a TSSOP20 lead frame that can solve at least one of the defects in the aforementioned background art.

[0006] Another object of this application is to provide a stamping component that can solve at least one of the defects in the above-mentioned background art.

[0007] To achieve at least one of the above objectives, the technical solution adopted in this application is as follows: a TSSOP20 lead frame, comprising a rectangular frame and sub-units, wherein the sub-units include a base island and pins, the base island is recessed below the rectangular frame, the base island is rectangular in shape, and the corners of the base island are curved, and both ends of the base island are provided with first connecting ribs, the other end of the first connecting ribs being connected to the rectangular frame; the pins are evenly spaced on the side of the base island and there is an included angle between them, the pins are provided with second connecting ribs, and the other end of the second connecting ribs being connected to the rectangular frame.

[0008] With the above settings, the sub-unit can compactly encapsulate the chip, making the hollow area near the base island and the pins uniform, enhancing the heat dissipation capacity of the lead frame; setting the four corners of the base island into an arc shape can effectively reduce the stress at the four corners of the base island and avoid the base island from breaking during subsequent processing and use; at the same time, the first connecting rib and the second connecting rib can further improve the overall structural strength of the lead frame.

[0009] Preferably, the pins include "one"-shaped pins and "L"-shaped pins. The "one"-shaped pins are symmetrically arranged above and below the base island; the "L"-shaped pins are symmetrically arranged at the four corners of the base island, and the openings of the "L"-shaped pins face the corners of the base island. With such a setting, the "one"-shaped pins can effectively increase the contact area between the pins and the base island to achieve a more effective locking effect, while the "L"-shaped pins can lock the four corners of the base island, making the structural shape of the base island more stable and avoiding thermal cycling stress cracking of the base island.

[0010] Preferably, the inner corner of the "L"-shaped pin also has a radian, and the radian of the "L"-shaped pin is the same as the radian of the corner of the base island. With such a setting, a more fitting edge-locking can be performed on the four sides of the base island, and the stress inside the base island can be evenly diffused to the "L"-shaped pins.

[0011] Preferably, the distance between adjacent pins ranges from 0.200 mm ± 0.025 mm, and the angle between the pins and the base island is 30°. With such a setting, the pins can be more fitted to the circuit structure, and the elastic design after bending can further buffer external forces. When the lead frame is impacted or vibrated, the pins can absorb kinetic energy through their own deformation, reducing the probability of pin breakage.

[0012] Preferably, the pins are provided with a plating layer; the outer edge of the base island is provided with a plating layer. With such a setting, on the one hand, the resistance can be reduced and the signal transmission loss can be reduced, and on the other hand, the surfaces of the pins and the base island can be prevented from oxidation, improving their corrosion resistance.

[0013] Preferably, the electroplating areas on the pins and the base island form a "hui" character shape, and the width range of the electroplating area is 0.700 mm to 1.100 mm. With such a setting, the coverage area of the electroplating layer can be increased, making the electroplating layer smoother, and improving the corrosion resistance and wear resistance of the product.

[0014] Preferably, a plurality of rectangular holes are symmetrically arranged on the upper and lower sides of the sub-unit, and positioning holes are arranged on the rectangular frame. The positioning holes are located at the head and tail ends of a plurality of sub-units arranged in columns. With such a setting, the heat dissipation effect of the lead frame can be further improved through the rectangular holes; the positioning holes play a positioning role in the subsequent processing of the lead frame, and the processing machine can quickly carry out work by identifying the positioning holes.

[0015] A stamping assembly is provided for stamping the aforementioned TSSOP20 leadframe. The stamping assembly includes an upper die and a lower die. The lower die has a recessed plate, and the upper die has a stamping plate for engaging the recessed plate to stamp the leadframe. A positioning structure is provided between the upper and lower dies. This configuration allows the leadframe to be placed inside the recessed plate, and the sheet metal is stamped into the desired shape by the extrusion pressure of the stamping plate. The positioning structure ensures that the leadframe does not shift during the stamping process, thereby improving the yield rate of the leadframe.

[0016] Preferably, the concave plate is provided with multiple sets of stamping holes, and the stamping plate is provided with a punch. The punch cooperates with the stamping holes to stamp and form the pin gap. The concave plate is also provided with an adjustment component for adjusting the size of the pin gap. The positioning structure consists of multiple sets of cooperating positioning slots and positioning pins. Both the stamping plate and the concave plate are provided with through holes. One end of the positioning pin is connected to the upper or lower die via a spring, and the other end passes through the through hole and extends into the positioning slot. With this configuration, the adjustment component can be adjusted according to actual needs, and then the punch is used to stamp and form the pin gap on the lead frame. During stamping, the positioning pin is inserted into the positioning slot to define the stamping point.

[0017] Preferably, the concave plate is further provided with a bending module and a shearing module, wherein the bending module is used to bend the pins and the shearing module is used to cut the rectangular frame.

[0018] Compared with the prior art, the beneficial effects of this application are as follows:

[0019] This invention sets the corners of the base island to be arc-shaped, which can effectively reduce the stress at the four corners of the base island and prevent the base island from breaking during subsequent processing and use. Then, the "I"-shaped pins are used to increase the contact area between the pins and the base island, and the "L"-shaped pins lock the four corners of the base island, making the structural shape of the base island more stable and preventing the base island from cracking due to thermal cycling stress. In addition, the inner corner arc of the "L"-shaped pins is the same as the corner arc of the base island, which can ensure that the stress inside the base island can be evenly diffused to the "L"-shaped pins.

[0020] When stamping the lead frame, the stamping plate and the concave plate can limit the lead frame through the positioning structure to prevent the lead frame from shifting at the placement angle when it is squeezed, thus ensuring that the processed lead frame has a high yield. The adjustment component can adjust the gap between adjacent pins according to actual needs, further improving processing efficiency. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the TSSOP20 lead frame in this application.

[0022] Figure 2 This is a schematic diagram of the structure of a subunit in this application. Figure 1 .

[0023] Figure 3 This is a schematic diagram of the side structure of a subunit in this application. Figure 2 .

[0024] Figure 4 This is a schematic diagram of the stamping assembly in this application. Figure 1 .

[0025] Figure 5 This is a schematic diagram of the concave plate in this application.

[0026] Figure 6 This is a schematic diagram of the stamping assembly in this application. Figure 2 .

[0027] In the diagram: 1. Rectangular frame; 11. Rectangular hole; 12. Positioning hole; 100. First connecting rib; 2. Sub-unit; 21. Base island; 22. Pin; 200. Second connecting rib; 3. Upper die; 31. Stamping plate; 300. Bending module; 301. Shearing module; 310. Punch; 4. Lower die; 41. Lower concave plate; 400. Positioning pin; 401. Positioning groove; 402. Through hole; 403. Spring; 410. Stamping hole; 5. Adjustment component. Detailed Implementation

[0028] The present application will be further described below with reference to specific embodiments. It should be noted that, without conflict, the various embodiments or technical features described below can be arbitrarily combined to form new embodiments.

[0029] In the description of this application, it should be noted that the terms "center", "lateral", "longitudinal", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc., which indicate the orientation and positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and should not be construed as limiting the specific protection scope of this application.

[0030] It should be noted that the terms "first," "second," etc., in the specification and claims of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0031] The terms “comprising” and “having”, and any variations thereof, in the specification and claims of this application are intended to cover non-exclusive inclusion, for example, a process, method, system, product, or device that includes a series of steps or units is not necessarily limited to those steps or units that are explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to such process, method, product, or device.

[0032] One aspect of this application provides a TSSOP20 lead frame, such as Figure 1 and Figure 2 As shown, one preferred embodiment includes a rectangular frame 1 and sub-units 2. The sub-units 2 are arranged in a specific sequence on the rectangular frame 1. Each sub-unit 2 includes a base island 21 and pins 22. The base island 21 is recessed into the rectangular frame 1 and is rectangular in shape. The corners of the base island 21 are rounded to reduce stress at the corners and prevent breakage during subsequent processing and use. Both ends of the base island 21 are provided with first connecting ribs 100, the other end of which is fixedly connected to the rectangular frame 1, further improving the connection stability of the base island 21. Multiple pins 22 are evenly spaced on the sides of the base island 21, with an included angle between the base island 21 and the pins 22. Second connecting ribs 200 are provided on the pins 22, the other end of which is fixedly connected to the rectangular frame 1.

[0033] Understandably, sub-unit 2 is used to package the chip, making the cutout area of ​​the base island 21 and the pin 22 close together uniform, enhancing the heat dissipation capacity of the lead frame. At the same time, the setting of the first connecting rib 100 and the second connecting rib 200 can make up for the deficiency of insufficient structural strength of the lead frame.

[0034] Furthermore, such as Figure 2 As shown, pin 22 includes an "I"-shaped pin 22 and an "L"-shaped pin 22. The "I"-shaped pin 22 is symmetrically arranged above and below the base island 21, which can effectively increase the contact area between the pin 22 and the base island 21 to achieve a more effective locking effect. The "L"-shaped pins 22 are symmetrically arranged at the four corners of the base island 21, and the opening of the "L"-shaped pin 22 faces the corner of the base island 21, so as to lock the four corners of the base island 21, making the structural shape of the base island 21 more stable and preventing the base island 21 from cracking due to thermal cycling stress.

[0035] It should be understood that when the lead frame is subjected to external force, the stress at the four corners of the base island 21 will spread outward along the arc. If the stress is transmitted to the inner corner of the "L"-shaped pin 22, the stress may be too concentrated, causing the pin 22 to break.

[0036] In view of the above, improvements have been made in some embodiments of this application, such as Figure 2 As shown, the inner corner of the "L"-shaped pin 22 also has a radian, and the radian of the "L"-shaped pin 22 is the same as that of the base island 21. To ensure that the pin 22 can perform a more fitting edge locking on the four sides of the base island 21, so that the stress inside the base island 21 can be evenly diffused to the "L"-shaped pin 22.

[0037] Specifically, as Figure 2 and Figure 3 shown, the distance range between adjacent pins 22 is 0.200 mm ± 0.025 mm, and the angle between the pin 22 and the base island 21 is 30°. To make the pin 22 more fitting to the circuit structure, provide more space for the placement of the chip. At the same time, the elastic design after bending can further buffer external forces. When the lead frame is impacted or vibrated, the pin 22 can absorb kinetic energy through its own deformation, reducing the probability of the pin 22 breaking.

[0038] In this embodiment, the pin 22 is provided with a plating layer, and the outer edge of the base island 21 is also provided with a plating layer. By plating the pin 22 and the base island 21, on the one hand, it can reduce the resistance and signal transmission loss, and on the other hand, it can prevent the surfaces of the pin 22 and the base island 21 from oxidation, improve their corrosion resistance, and make the product have a longer service life.

[0039] Specifically, the electroplating areas on the pin 22 and the base island 21 form a "hui" character shape, and the width range of the electroplating area is 0.700 mm to 1.100 mm. The "hui" character-shaped electroplating process is used to increase the coverage area of the electroplating layer, make the electroplating layer smoother, and improve the corrosion resistance and wear resistance of the product.

[0040] In this implementation, as Figure 1 shown, a plurality of rectangular holes 11 are symmetrically arranged on the upper and lower sides of the sub-unit 2, and positioning holes 12 are provided on the rectangular frame 1. The positioning holes 12 are located at the head and tail ends of a plurality of sub-units 2 arranged in columns. When the lead frame needs to be processed, the lead frame can be placed in the correct position through the positioning holes 12, so that the processing machine can quickly start working by identifying the positioning holes 12. The rectangular holes 11 can further improve the heat dissipation effect of the lead frame.

[0041] One aspect of the present application provides a stamping component, which can be used for stamping and producing the above-mentioned TSSOP20 lead frame, as Figure 4 and Figure 5As shown, one preferred embodiment includes an upper die 3 and a lower die 4. The lower die 4 is provided with a concave plate 41, and the upper die 3 is provided with a stamping plate 31 for the concave plate 41 to cooperate with the stamping of the lead frame. During the manufacturing process of the lead frame, the lead frame can be processed by the extrusion action of the stamping plate 31 and the concave plate 41. In addition, in order to ensure that the lead frame does not shift during the stamping process, a positioning structure is provided between the upper die 3 and the lower die 4, thereby improving the yield rate of the lead frame processing.

[0042] Furthermore, such as Figure 4 , Figure 5 and Figure 6 As shown, the lower concave plate 41 is provided with multiple sets of stamping holes 410, and the stamping plate 31 is provided with punches 310. The punches 310 cooperate with the stamping holes 410 to stamp and form the pin 22 gap. In order to further improve the adjustability of the stamping assembly, the lower concave plate 41 is also provided with an adjustment assembly 5 for adjusting the size of the pin 22 gap, so as to stamp and form different sizes of pin 22 gaps on the lead frame according to actual needs.

[0043] Specifically, the positioning structure consists of multiple sets of mutually cooperating positioning grooves 401 and positioning pins 400. Both the stamping plate 31 and the lower concave plate 41 are provided with through holes 402. One end of the positioning pin is connected to the upper die 3 or the lower die 4 via a spring 403, and the other end extends into the positioning groove 401 through the through hole 402. During stamping, the stamping point can be defined simply by inserting the positioning pin 400 into the positioning groove 401.

[0044] In this embodiment, as Figure 5 and Figure 6 As shown, the lower concave plate 41 is also provided with a bending module 300 and a shearing module 301. During the stamping process, the bending module 300 bends the pin 22 and the shearing module 301 cuts the rectangular frame 1.

[0045] The basic principles, main features, and advantages of this application have been described above. Those skilled in the art should understand that this application is not limited to the above embodiments. The embodiments and descriptions in the specification are merely the principles of this application. Various changes and modifications can be made to this application without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claims. The scope of protection claimed by this application is defined by the appended claims and their equivalents.

Claims

1. A TSSOP20 lead frame, characterized in that, It includes a rectangular frame (1) and sub-units (2). The sub-units (2) include a base island (21) and pins (22). The base island (21) sinks below the rectangular frame (1). The base island (21) is in a quasi-rectangular shape, and the corners of the base island (21) have arcs. Both ends of the base island (21) are provided with first connecting ribs (100), and the other ends of the first connecting ribs (100) are connected to the rectangular frame (1); the pins (22) are arranged on the side of the base island (21) and there is an included angle between them. The pins (22) are provided with second connecting ribs (200), and the other ends of the second connecting ribs (200) are connected to the rectangular frame (1).

2. The TSSOP20 lead frame as described in claim 1, characterized in that, The pins (22) include "one"-shaped pins (22) and "L"-shaped pins (22). The "one"-shaped pins (22) are symmetrically arranged above and below the base island (21); the "L"-shaped pins (22) are symmetrically arranged at the four corners of the base island (21), and the openings of the "L"-shaped pins (22) face the corners of the base island (21).

3. The TSSOP20 lead frame as described in claim 2, characterized in that, The inner corners of the "L"-shaped pins (22) also have arcs, and the arcs are the same as the corner arcs of the base island (21).

4. The TSSOP20 lead frame as described in claim 3, characterized in that, The distance range between adjacent pins (22) is 0.200 mm ± 0.025 mm, and the angle between the pins (22) and the base island (21) is 30°.

5. The TSSOP20 lead frame as described in claim 4, characterized in that, The pins (22) are provided with a plating layer, and the outer edges of the base island (21) are provided with a plating layer.

6. The TSSOP20 lead frame as described in claim 5, characterized in that, The electroplating areas on the pins (22) and the base island (21) form a "hui"-shaped (Chinese character for "return"), and the width range of the electroplating area is 0.700 mm to 1.100 mm.

7. The TSSOP20 lead frame as described in claim 1, characterized in that, On the upper and lower sides of the sub-units (2), a plurality of rectangular holes (11) are symmetrically arranged. On the rectangular frame (1), positioning holes (12) are arranged, and the positioning holes (12) are located at the head and tail ends of a plurality of sub-units (2) arranged in columns.

8. A stamping assembly, characterized in that, Applicable to stamping the TSSOP20 lead frame according to any one of claims 1-7. The stamping assembly includes an upper die (3) and a lower die (4). The lower die (4) is provided with a concave plate (41), and the upper die (3) is provided with a stamping plate (31) for cooperating with the concave plate (41) to stamp the lead frame; a positioning structure is arranged between the upper die (3) and the lower die (4).

9. The stamping assembly as described in claim 8, characterized in that, The concave plate (41) is provided with multiple groups of stamping holes (410), and the stamping plate (31) is provided with punches (310). The punches (310) cooperate with the stamping holes (410) to stamp and form pin (22) gaps; on the concave plate (41), an adjusting assembly (5) for adjusting the size of the pin (22) gaps is further arranged; the positioning structure is multiple groups of mutually cooperating positioning grooves (401) and positioning pins (400). Perforations (402) are arranged on both the stamping plate (31) and the concave plate (41). One end of the positioning pin (400) is connected to the upper die (3) or the lower die (4) through a spring (403), and the other end passes through the perforation (402) and extends into the positioning groove (401).

10. The stamping assembly as claimed in claim 9, characterized in that, The concave plate (41) is also equipped with a bending module (300) and a shearing module (301). The bending module is used to bend the pin (22), and the shearing module (301) is used to cut the rectangular frame (1).

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