SOT223 lead frame

Abstract

The utility model relates to an SOT223 lead frame, which comprises a frame and a plurality of installation units arranged on the frame, each installation unit comprises a base island, a first pin and a second pin symmetrically arranged relative to the base island, the lower end of the base island is connected with the first pin, the second pin comprises an outer pin and an inner pin, and the inner pin is connected with the outer pin. The upper ends of the outer pins are connected with the lower ends of the inner pins, the sides, away from the base island, of the outer pins are flush with the sides, away from the base island, of the inner pins, and the sides, close to the base island, of the inner pins protrude out of the sides, close to the base island, of the outer pins. The SOT223 lead frame obtained by the utility model has the following advantages: the overall width of the inner pin is large, so that the overall inner pin has high structural strength and is not easy to deform, the outer side of the inner pin is flush with the outer side of the outer pin, plastic package materials flow on the outer side more smoothly during packaging, the stress on the outer side of the second pin is more uniform, the overall structure is simple, and the cost is low. And design and processing of the blanking die are facilitated.

Description

Technical Field

[0001] This utility model relates to the field of integrated circuit technology, and in particular to an SOT223 lead frame. Background Technology

[0002] In the prior art, such as Chinese Utility Model Patent Publication No. CN 204088299 U, a novel SOT223-3L package lead frame is disclosed, including left and right outer pins, a middle outer pin, left and right inner pins respectively connected to the upper ends of the left and right outer pins, a carrier connected to the middle outer pin at the lower end, and a heat sink connected to the upper end of the carrier. The upper outer side of the left and right inner pins is provided with a semi-circular guide hole, the lower part of the left and right inner pins and the lower part of the carrier are provided with an elliptical force-bearing hole, the lower part of the heat sink is provided with a circular force-bearing hole, and the lower end of the heat sink and the front of the carrier are provided with a groove. The left and right inner pins and the back of the carrier are provided with multiple pits. The distance between the inner side of the left and right inner pins and the carrier is smaller than the distance between the inner side of the outer pins on the same side and the carrier, and the width of the heat sink is greater than that of the carrier. However, the structural strength of the inner pins on the left and right sides of the new SOT223-3L package lead frame is low and they are easy to deform. The top of the inner pins on the left and right sides is arranged with semi-circular guide holes, which makes them more prone to deformation under stress during package filling. The structure of the inner pins on the left and right sides is complex, and the design of the punching die is difficult. Utility Model Content

[0003] One objective of this application is to provide an SOT223 lead frame that can improve the strength of the internal pin structure.

[0004] The technical solution adopted in this application is: an SOT223 lead frame, including a frame and a plurality of mounting units disposed on the frame. The mounting unit includes a base island, a first pin and a second pin symmetrically arranged relative to the base island. The lower end of the base island is connected to the first pin. The second pin includes an outer pin and an inner pin. The upper end of the outer pin is connected to the lower end of the inner pin. The side of the outer pin away from the base island is flush with the side of the inner pin away from the base island. The side of the inner pin near the base island protrudes beyond the side of the outer pin near the base island.

[0005] Compared with the prior art, the advantages of this application are that the overall width of the inner pin is large, which makes the structure of the entire inner pin high and not easy to deform. The outer side of the inner pin is flat with the outer side of the outer pin, so the molding compound flows more smoothly on the outer side during encapsulation. The force on the outer side of the second pin is more uniform. Moreover, the overall structure is simple and easy to design and process with stamping dies.

[0006] In some embodiments of this application, a semi-circular guide hole is provided on the side of the inner pin away from the base island.

[0007] Furthermore, the center of the semicircular guide hole is located inside the inner pin; a rectangular hole is provided between the semicircular guide hole and the side of the inner pin, the upper and lower sides of the rectangular hole are tangent to the upper and lower ends of the semicircular guide hole respectively, and the outer side of the rectangular hole is flush with the side of the inner pin.

[0008] In some embodiments of this application, a heat sink is also included, the lower end of which is connected to the base island, and the width of the heat sink is greater than the width of the base island; the heat sink is provided with stress holes.

[0009] In some embodiments of this application, the base island has grooves at its upper and lower ends, and the grooves have a semi-circular cross-section.

[0010] In some embodiments of this application, the top of the outer pin is lower than the top of the base island; the bottom of the outer pin is flush with the bottom of the base island.

[0011] In some embodiments of this application, the second pin on the right side is in the shape of an L after being rotated 180°.

[0012] In some embodiments of this application, multiple installation units are arranged on the frame in a row A × column B manner, and in groups of two columns.

[0013] Furthermore, the external pins of two adjacent mounting units in the same column are staggered. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the structure of Embodiment 1 of this utility model;

[0015] Figure 2 This is a schematic diagram of the installation unit of Embodiment 1 of this utility model;

[0016] Figure 3 yes Figure 2 Enlarged view of part A in the image;

[0017] Figure 4 yes Figure 2 A cross-sectional view of the base island in the BB direction.

[0018] In the diagram: 1. Frame; 2. Mounting unit; 3. Base island; 4. First pin; 5. Second pin; 6. Outer pin; 7. Inner pin; 8. Semi-circular air guide hole; 9. Rectangular hole; 10. Heat sink; 11. Force-bearing hole; 12. Groove. Detailed Implementation

[0019] To further illustrate the technical means and effects adopted by this utility model in order to achieve the intended utility model purpose, the following detailed description of the specific implementation methods, structure, features and effects of this utility model is provided in conjunction with the accompanying drawings and preferred embodiments.

[0020] Example 1:

[0021] This embodiment provides an SOT223 lead frame, such as Figure 1 , Figure 2 As shown, the device includes a frame 1 and multiple mounting units 2 disposed on the frame 1. Each mounting unit 2 includes a base island 3, a first pin 4, and a second pin 5 symmetrically arranged relative to the base island 3. The lower end of the base island 3 is connected to the first pin 4. The second pin 5 includes an outer pin 6 and an inner pin 7. The upper end of the outer pin 6 is connected to the lower end of the inner pin 7. The side of the outer pin 6 away from the base island 3 is flush with the side of the inner pin 7 away from the base island 3. The side of the inner pin 7 near the base island 3 protrudes beyond the side of the outer pin 6 near the base island 3.

[0022] The large overall width of the inner pin 7 makes the structure of the inner pin 7 strong and not easily deformed. The outer side of the inner pin 7 is flat with the outer side of the outer pin 6, so the molding compound flows more smoothly on the outer side during encapsulation. The force on the outer side of the second pin 5 is more uniform, and the overall structure is simple, which is convenient for the design and processing of the stamping die.

[0023] For secure and reliable sealing, such as Figure 3 As shown, the inner pin 7 has a semi-circular flow guide hole 8 on the side away from the base island 3. The design of the semi-circular flow guide hole 8 can facilitate the flow of molding compound through the semi-circular flow guide hole 8, so that the upper and lower surfaces of the inner pin 7 are well connected, increasing the contact area between the molding compound and the lead frame, and the overall fixing effect is better.

[0024] To ensure reliable encapsulation and fixation, the center of the semicircular guide hole 8 is located inside the inner pin 7. A rectangular hole 9 is provided between the semicircular guide hole 8 and the side of the inner pin 7. The upper and lower sides of the rectangular hole 9 are tangent to the upper and lower ends of the semicircular guide hole 8, respectively. The outer side of the rectangular hole 9 is flush with the side of the inner pin 7. The rectangular hole 9 communicates with the semicircular guide hole 8. The semicircular guide hole 8 extends into the inner pin 7, increasing the contact area between the molding compound and the lead frame, resulting in better overall fixation.

[0025] To ensure heat dissipation, a heat sink 10 is also included. The lower end of the heat sink 10 is connected to the base island 3. The width of the heat sink 10 is greater than the width of the base island 3, resulting in a large heat dissipation area. The heat sink 10 is provided with a force-bearing hole 11. During encapsulation, the molding compound flows through the force-bearing hole 11, thereby forming a pin made of molding compound to ensure a fixing effect.

[0026] To ensure a consistent effect, such as Figure 4 As shown, the base island 3 has grooves 12 at both its upper and lower ends, and the cross-section of the grooves 12 is semi-circular. The design of the grooves 12 allows the molding compound to flow into the grooves 12, improving the bonding force between the molding compound and the base island 3. The semi-circular cross-section of the grooves 12 provides a large contact area, which also facilitates the flow of molding compound through the grooves 12.

[0027] For structural reliability, the top of the external pin 6 is lower than the top of the base island 3, ensuring the spacing between the top of the external pin 6 and the heat sink 10; the bottom of the external pin 6 is flush with the bottom of the base island 3.

[0028] The second pin 5 on the right side is L-shaped after being rotated 180°. The overall structure of the second pin 5 is simple, which facilitates the design of the punching die.

[0029] Multiple installation units 2 are arranged on the frame 1 in a row A × column B manner, and in groups of two columns.

[0030] The external pins 6 of two adjacent mounting units 2 in the same column are staggered.

[0031] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model in any way. Although the present utility model has been disclosed above with reference to a preferred embodiment, it is not intended to limit the present utility model. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present utility model. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present utility model without departing from the scope of the present utility model shall still fall within the scope of the present utility model.

Claims

1. An SOT223 lead frame, comprising a frame (1) and a plurality of mounting units (2) disposed on the frame (1), characterized in that, The mounting unit (2) includes a base island (3), a first pin (4), and a second pin (5) symmetrically arranged relative to the base island (3). The lower end of the base island (3) is connected to the first pin (4). The second pin (5) includes an outer pin (6) and an inner pin (7). The upper end of the outer pin (6) is connected to the lower end of the inner pin (7). The side of the outer pin (6) away from the base island (3) is flush with the side of the inner pin (7) away from the base island (3). The side of the inner pin (7) near the base island (3) protrudes beyond the side of the outer pin (6) near the base island (3).

2. The SOT223 lead frame according to claim 1, characterized in that: The inner pin (7) is provided with a semi-circular guide hole (8) on the side away from the base island (3).

3. The SOT223 lead frame according to claim 2, characterized in that: The center of the semicircular guide hole (8) is located inside the inner pin (7); a rectangular hole (9) is provided between the semicircular guide hole (8) and the side of the inner pin (7), the upper and lower sides of the rectangular hole (9) are tangent to the upper and lower ends of the semicircular guide hole (8) respectively, and the outer side of the rectangular hole (9) is flush with the side of the inner pin (7).

4. The SOT223 lead frame according to claim 1, characterized in that: It also includes a heat sink (10), the lower end of which is connected to the base island (3), and the width of the heat sink (10) is greater than the width of the base island (3); the heat sink (10) is provided with a force-bearing hole (11).

5. The SOT223 lead frame according to claim 1, characterized in that: The base island (3) has grooves (12) at its upper and lower ends, and the cross-section of the grooves (12) is semi-circular.

6. The SOT223 lead frame according to claim 1, characterized in that: The top of the outer pin (6) is lower than the top of the base island (3); the bottom of the outer pin (6) is flush with the bottom of the base island (3).

7. The SOT223 lead frame according to claim 1, characterized in that: The second pin (5) on the right side is in the shape of an L after being rotated 180°.

8. The SOT223 lead frame according to claim 1, characterized in that: Multiple installation units (2) are arranged on the frame (1) in a row A × column B manner, and in groups of two columns.

9. The SOT223 lead frame according to claim 8, characterized in that: The external pins (6) of two adjacent mounting units (2) in the same column are staggered.

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