Semiconductor lead frame and packaging structure

Abstract

The utility model relates to the technical field of semiconductor packaging, in particular to a semiconductor lead frame and a packaging structure, which are characterized in that pins (namely drain pins) integrally connected with a chip welding area are moved to the opposite sides of the other pins, so that the creepage distance between the pins is increased, and the semiconductor lead frame and the packaging structure are suitable for the field of higher voltage; and the heat dissipation performance can be improved by arranging the pin and the heat dissipation surface at different side positions and widening the width of the pin of the drain electrode.

Description

Technical Field

[0001] The utility model relates to the technical field of semiconductor packaging, in particular to a semiconductor lead frame and a packaging structure. Background Art

[0002] The surface-mount device structure is a very mature power device structure on the market. This structure has many products on the market, such as IGBT (gate bipolar transistor), MOS (metal oxide field effect transistor), diode, etc., and is often used in electronic fields such as industrial control and white appliances. The surface-mount device packaging structure generally includes a metal frame, which includes a PAD area for installing the chip (that is, the chip welding area, which is also the main heat dissipation area) and several pins connected to the PAD area. During packaging, the chip is supported, protected and heat-dissipated by wrapping the plastic package outside the frame. The back of the metal base in the PAD area and part of the pins are exposed outside the plastic package to achieve electrical connection between the chip and the external structure of the plastic package. For example, the typical surface-mount package TO263.

[0003] The existing TO263 lead frame is designed with three pins. After encapsulation, the creepage distance between the device pins is small and the voltage range is narrow. In order to ensure safety during high-voltage output and increase the reliability of packaged products, the patent document with the prior art application number 202121838812.5 provides a new TO-263 lead frame. This solution directly removes the middle pin connected to the carrier area (i.e., the above-mentioned PAD area) when designing the lead frame, and only sets two pins with a spacing (as the gate G and the source S, respectively), and separates both pins from the carrier area, thereby increasing the creepage distance between the heat dissipation area and the pins, ensuring the safety of high-voltage output. When the device encapsulated by the lead frame of this structural form is directly connected to the circuit board for electrical characteristics, the metal base of the chip (connecting the MOSFET drain D) extending out of the heat dissipation area of ​​the plastic package needs to be welded on the circuit board, which is used to output large current on the one hand and dissipate heat through the PCB on the other hand. However, the thermal conductivity of the plastic package and the PCB circuit board are both low and the thermal resistance is large, resulting in the inability to effectively dissipate the heat of the semiconductor power device and the poor overall heat dissipation of the system. Studies have shown that for every 10°C increase in power semiconductor temperature, the device failure rate doubles.

[0004] However, if the heat dissipation surface is directly set on the top of the device (i.e. the pins and the heat dissipation surface are set on different sides of the plastic package) in order to improve the heat dissipation performance of the device, it will not only reduce the support strength of the device connection, but also fail to maintain the realization of normal functions. The current needs to pass through the metal base of the chip to reach the entire electronic circuit. Therefore, it is necessary to improve the existing TO263 lead frame and its packaging structure so that the packaged device has better heat dissipation performance and can meet the design requirements of a larger creepage distance. Utility Model Content

[0005] The purpose of the utility model is to provide a semiconductor lead frame and a packaging structure that can improve the heat dissipation performance of the device and meet the design requirements of higher voltage fields while improving the heat dissipation performance of the device.

[0006] In order to achieve the above purpose, the technical solution adopted by the utility model is:

[0007] A semiconductor lead frame comprises a frame body, wherein the frame body is provided with a plurality of lead frame units, wherein the lead frame units are arranged in rows and columns, wherein the lead frame units comprise a chip welding area and a plurality of pins, wherein the plurality of pins are arranged on opposite sides of the chip welding area, wherein the pins on one side are integrally connected to the chip welding area, and the pins on the other side are isolated from the chip welding area.

[0008] The semiconductor lead frame provided by the utility model increases the creepage distance between the pins by moving the pins (i.e., the drain pins) connected integrally with the chip welding area to the opposite side of the other pins, which is conducive to adapting to higher voltage fields, and can also improve the heat dissipation performance by widening the width of the drain pins; the packaging structure prepared by adopting this structural form has pins distributed on the opposite sides of the plastic package body, and has high connection strength after being welded on the PCB board, and does not affect the application of arranging the back side of the chip welding area on the top of the device for heat dissipation. When the back side of the chip welding area and the pins are arranged on the opposite side of the plastic package body, the current can also reach the entire electronic circuit through the chip welding area and the pins connected integrally therewith, and does not affect the realization of the normal function of the device; wherein, in order to meet the requirement that the pins can be used for connection with the PCB, each pin should have a sufficient length to facilitate bending processing in subsequent processes.

[0009] Therefore, the use of the above-mentioned semiconductor lead frame structure is conducive to meeting the design requirements of improving the heat dissipation performance of the device and adapting to higher voltage fields. In other words, the packaging structure obtained by using the above-mentioned semiconductor lead frame structure can realize the setting of the heat dissipation surface of the pin and the chip welding area on the opposite sides of the plastic package. In the case of setting the heat dissipation surface of the pin and the chip welding area on the opposite sides of the plastic package, since one side of the pin is integrally connected with the chip welding area, it serves as a drain pin connection circuit, which does not affect the realization of the normal function of the device; moreover, since both sides have pins for PCB connection, the support strength is good, the drain pin is moved to the opposite side of the remaining pins, and the creepage distance between the pins is large, which can be applied to higher voltage fields.

[0010] As a preferred solution of the utility model, the pins include a first pin, a second pin, a third pin and a fourth pin, the first pin and the second pin are located on the same side of the chip welding area, that is, as the A side, the first pin and the second pin are isolated from the chip welding area; the third pin and the fourth pin are located on the same side of the chip welding area, that is, as the B side, the A side and the B side are opposite sides of the chip welding area, and the third pin and the fourth pin are respectively connected to the chip welding area as a whole. This solution has good support strength by leading out at least the third pin and the fourth pin from the chip welding area as drain pins and setting them on the same side of the chip welding area and opposite to the other pins; the drain pin can improve the heat dissipation capacity of the device by widening the pin width.

[0011] As a preferred solution of the utility model, the chip welding area integrally extends out of the top heat dissipation area along the direction of the B side, and the third pin and the fourth pin are respectively integrally connected to the top heat dissipation area; a first limiting hole is provided at the top heat dissipation area, the center line of the first limiting hole is located at the encapsulation line position, and the first limiting hole is located between the third pin and the fourth pin. This is conducive to ensuring that the plastic package can be well combined with the frame and the third pin and the fourth pin have good connection strength.

[0012] As a preferred solution of the utility model, the first pin is provided with a first pin welding area, the second pin is provided with a second pin welding area, and the connecting part between the first pin and the first pin welding area and the connecting part between the second pin and the second pin welding area are both provided with a groove and a second limiting hole, which is beneficial to ensure the air tightness of the device and realize the close combination of the plastic package body and the frame.

[0013] As a preferred solution of the utility model, the two adjacent rows of lead frame units are arranged symmetrically, and the two adjacent rows of lead frame units are located close to each other on the B side; the ends of the third pin and the fourth pin are both suspended, and a first connecting rib is provided between the third pin and the fourth pin, and the first connecting rib longitudinally connects the two adjacent chip welding areas. By providing the first connecting rib between the two adjacent rows of lead frame units, the first connecting rib connects the chip welding areas of the two adjacent rows of lead frame units between the third pin and the fourth pin, thereby strengthening the connection between the lead frame units and improving the frame strength.

[0014] As a preferred solution of the utility model, a second connecting rib is provided between adjacent first connecting ribs, and the second connecting rib is laterally connected to each of the first connecting ribs and extends laterally to the frame body, thereby strengthening the connection between the lead frame units and improving the strength of the frame structure.

[0015] As a preferred solution of the utility model, every two rows of lead frame units are arranged as one unit, and a flow channel is set between two adjacent chip welding areas in the same unit to save frame materials.

[0016] As a preferred solution of the utility model, 2 rows and 20 columns of the lead frame units are arranged on the frame body, and the length of the frame body is 283.8±0.1 mm and the width is 50.24±0.1 mm.

[0017] As a preferred solution of the utility model, the plane position where the chip welding area is located is lower than the plane position where the isolated pins are located.

[0018] The utility model also provides a semiconductor packaging structure, including a plastic package and a lead frame unit, the lead frame unit including a chip welding area and a plurality of pins connected to the chip welding area, the plastic package is sealed on the lead frame unit and exposes the back of the chip welding area and part of the structure of the pins, a plurality of pins are distributed on two opposite sides of the plastic package, and the pins on one side are integrally connected to the chip welding area, and the pins on the other side are isolated from the chip welding area, the parts of each pin exposed outside the plastic package are bent away from the side where the chip welding area is located, the ends of the pins and the back of the chip welding area are located on two opposite sides of the plastic package, and the ends of the pins are used for welding on a PCB circuit board.

[0019] The semiconductor packaging structure provided by the utility model moves the drain pin (i.e., the pin connected to the chip welding area as a whole) to the opposite side of the other pins, and bends each pin in the opposite direction, so that the pin and the heat dissipation surface are located on different sides of the plastic package, so that the device can be connected to the radiator upward through the heat dissipation surface on the top, so that the heat can be effectively dissipated through the back of the chip welding area and the radiator, which greatly reduces the thermal resistance of the semiconductor device in the electronic device, reduces the temperature rise of the device, and is conducive to improving the reliability of the device and the reliability of the electronic device system; at the same time, it also increases the creepage distance between the device pins, so that the device can be used in a higher voltage field; and the heat dissipation capacity of the device can be further improved by widening the width of the drain pin. The packaging structure has good support strength.

[0020] The semiconductor lead frame and packaging structure provided by the utility model are not only applicable to all series of TO263 devices, but also applicable to devices with similar appearance and structure such as TO252.

[0021] In summary, due to the adoption of the above technical solution, the beneficial effects of the utility model are:

[0022] The semiconductor lead frame and packaging structure provided by the utility model increase the creepage distance between the pins by moving the pins (i.e., the drain pins) integrally connected to the chip welding area to the opposite side of the other pins, which is conducive to adapting to higher voltage fields. The heat dissipation performance can also be improved by arranging the pins and the heat dissipation surface at different side positions and widening the drain pin width. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a schematic structural diagram of a semiconductor lead frame in Example 1;

[0024] Figure 2 It is a schematic diagram of the structure of a single lead frame unit;

[0025] Figure 3 yes Figure 2 Left view of

[0026] Figure 4 is a structural schematic diagram of a semiconductor packaging structure in Example 2;

[0027] Figure 5 yes Figure 4 Rear view of

[0028] Figure 6 yes Figure 5 Left view of

[0029] Figure 7 yes Figure 5 perspective drawing;

[0030] Figure 8 yes Figure 6 perspective view.

[0031] Icons: 1-frame body; 2-lead frame unit; 21-chip welding area; 22-first pin; 221-first pin welding area; 23-second pin; 231-second pin welding area; 24-third pin; 25-fourth pin; 26-top heat dissipation area; 27-first limiting hole; 28-second limiting hole; 3-first connecting rib; 4-second connecting rib; 5-flow channel; 6-plastic package; 7-chip; 8-bonding wire. DETAILED DESCRIPTION

[0032] The utility model is described in detail below in conjunction with the accompanying drawings.

[0033] In order to make the purpose, technical solution and advantages of the utility model more clear, the utility model is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the utility model and are not used to limit the utility model.

[0034] Example 1

[0035] A semiconductor lead frame, such as Figure 1-Figure 3 As shown, it includes a frame body 1, the frame body 1 is provided with a plurality of lead frame units 2, the lead frame units 2 are arranged in rows and columns, the lead frame units 2 include a chip welding area 21 and a plurality of pins, the plurality of pins are arranged on opposite sides of the chip welding area 21, the pins on one side are integrally connected with the chip welding area 21, and the pins on the other side are isolated from the chip welding area 21.

[0036] The semiconductor lead frame increases the creepage distance between the pins by moving the pins (i.e., the drain pins) integrally connected to the chip welding area 21 to the opposite side of the remaining pins, which is conducive to adapting to higher voltage fields, and can also improve the heat dissipation performance by widening the drain pin width; the packaging structure obtained by adopting this structural form has pins distributed on opposite sides of the plastic package 6, and has high connection strength after being welded on the PCB board, which does not affect the application of setting the back side of the chip welding area 21 on the top of the device for heat dissipation. When the back side of the chip welding area 21 and the pins are located on the opposite side of the plastic package 6, the current can also reach the entire electronic circuit through the chip welding area 21 and the pins integrally connected thereto, without affecting the realization of the normal function of the device; wherein, in order to meet the requirement that the pins can be used for connection with the PCB, each pin should have a sufficient length to facilitate bending processing in subsequent processes.

[0037] Therefore, the use of the above-mentioned semiconductor lead frame structure is conducive to meeting the design requirements of improving the heat dissipation performance of the device and adapting to higher voltage fields. In other words, the packaging structure obtained by using the above-mentioned semiconductor lead frame structure can realize the setting of the heat dissipation surface of the pin and the chip welding area 21 on the opposite sides of the plastic package 6. In the case of setting the heat dissipation surface of the pin and the chip welding area 21 on the opposite sides of the plastic package 6, since one side of the pin is integrally connected with the chip welding area 21, it serves as a drain pin connection circuit, which does not affect the realization of the normal function of the device; and since both sides have pins for PCB connection, the support strength is good, the drain pin is moved to the opposite side of the remaining pins, and the creepage distance between the pins is large, which can be applied to higher voltage fields.

[0038] This embodiment takes TO263 as an example, and moves the middle pin of the original three-pin side to the other side, which greatly increases the creepage distance between the device pins (the creepage distance between the D and S pins is increased from 1.27mm of the standard TO263 to 4mm), and can be applied to higher voltage fields. At the same time, by widening the pin width of the D pole, the heat dissipation capacity of the device is also improved to a certain extent. Specifically, the pins include a first pin 22, a second pin 23, a third pin 24 and a fourth pin 25. The first pin 22 and the second pin 23 are located on the same side of the chip welding area 21, that is, as the A side, and the first pin 22 and the second pin 23 are isolated from the chip welding area 21; the third pin 24 and the fourth pin 25 are located on the same side of the chip welding area 21, that is, as the B side, and the A side and the B side are opposite sides of the chip welding area 21. The third pin 24 and the fourth pin 25 are respectively connected to the chip welding area 21 as a whole. The third pin 24 and the fourth pin 25 are led out from the chip welding area 21 as drain pins and arranged on the same side of the chip welding area 21 and opposite to the other pins, so that the support strength is good. Each pin is used to be reversely bent to the chip welding area 21 on the opposite side of the plastic package 6. In order to realize the welding connection between the pin and the PCB, each pin should have a sufficient length to facilitate bending in subsequent processes.

[0039] The chip welding area 21 extends out of the top heat dissipation area 26 in the direction of the B side, and the third pin 24 and the fourth pin 25 are respectively connected to the top heat dissipation area 26 in one piece; a first limiting hole 27 is provided at the top heat dissipation area 26, the center line of the first limiting hole 27 is located at the encapsulation line position, and the first limiting hole 27 is located between the third pin 24 and the fourth pin 25. This is conducive to ensuring that the plastic package 6 can be well combined with the frame and the third pin 24 and the fourth pin 25 have good connection strength. Further, the first pin 22 is provided with a first pin welding area 221, the second pin 23 is provided with a second pin welding area 231, and the connecting part of the first pin 22 and the first pin welding area 221 and the connecting part of the second pin 23 and the second pin welding area 231 are both provided with a groove and a second limiting hole 28, which is conducive to ensuring the airtightness of the device and realizing the close combination of the plastic package 6 and the frame. In the lead frame, the first pin 22 and the second pin 23 are in the same plane, the third pin 24 and the fourth pin 25 and the chip welding area 21 are in the same plane, and the plane position of the chip welding area 21 is lower than the plane position of the first pin 22 and the second pin 23, which is conducive to the close arrangement of a single frame, improves the frame density, and reduces the overall design size of the frame.

[0040] The setting of the limiting hole, such as size, shape, position, etc., is determined according to the actual situation and is not limited to the first limiting hole 27 and the second limiting hole 28 mentioned above; after the plastic package body 6 is formed, a limiting column will be formed at the limiting hole, so that the plastic package body 6 and the frame are locked with each other through the limiting column and the hole axis of the limiting hole, avoiding the separation of the plastic package body 6 and the frame. The setting of the groove is also not limited to the junction of the pin and the pin welding area, and can also be set at the junction of the frame and the plastic package body 6, etc. The specific parameters of the groove structure, such as depth, length, number, cross-sectional shape, and distribution position, are determined according to the actual situation.

[0041] In this embodiment, two adjacent rows of lead frame units 2 are arranged symmetrically, and the two adjacent rows of lead frame units 2 are located close to each other on the B side, that is, the top heat dissipation areas 26 of the two adjacent rows of lead frame units 2 face the top heat dissipation areas 26; the ends of the third pin 24 and the fourth pin 25 are both suspended, and a first connecting rib 3 is provided between the third pin 24 and the fourth pin 25. The first connecting rib 3 is longitudinally arranged, and its two ends are integrally connected to the top heat dissipation areas 26 of the two adjacent rows of lead frame units 2, and longitudinally connects two adjacent chip welding areas 21. By arranging the first connecting rib 3 between the two adjacent rows of lead frame units 2, the first connecting rib 3 connects the chip welding areas 21 of the two adjacent rows of lead frame units 2 between the third pin 24 and the fourth pin 25, thereby strengthening the connection between the lead frame units 2 and improving the frame strength.

[0042] Furthermore, second connecting ribs 4 are provided between adjacent first connecting ribs 3, and the second connecting ribs 4 are transversely connected to the first connecting ribs 3 and extend transversely to the frame body 1, so as to strengthen the connection between the lead frame units 2 and improve the strength of the frame structure. A circular hole is provided at the intersection of the first connecting ribs 3 and the second connecting ribs 4 for frame positioning, which is also conducive to saving frame materials and reducing weight.

[0043] The frame mainly supports the chip 7, and serves as a telecommunication connection and heat dissipation function between the chip 7 and the outside world. The frame can be made of a plate or strip member made of metal. In this embodiment, the frame is a two-row parallel structure. The length of the frame body 1 is 283.8 mm and the width is 50.24 mm. 20×2=40 lead frame units 2 can be arranged on the frame body 1, and the pin width is 1.27 mm; every two rows of lead frame units 2 are arranged as a unit, and a flow channel 5 is set between two adjacent chip welding areas 21 in the same unit, which is also conducive to saving frame materials and improving frame density.

[0044] Example 2

[0045] Based on Example 1, this embodiment also provides a semiconductor packaging structure, which can be prepared by the lead frame provided in Example 1. Figure 4-Figure 8As shown, the semiconductor packaging structure includes a plastic package 6 and a lead frame unit 2. The lead frame unit 2 includes a chip welding area 21 and a plurality of pins connected to the chip welding area 21. The pins include a first pin 22, a second pin 23, a third pin 24 and a fourth pin 25. The front of the chip welding area 21 is used for welding the chip 7. The plastic package 6 covers the lead frame unit 2 and the chip 7 and exposes the back of the chip welding area 21 and part of the structure of the pins to achieve electrical connection and heat dissipation between the chip 7 and the external structure of the plastic package 6. The plastic package 6 provides support for the chip 7. , protection and heat dissipation; a number of pins are distributed on opposite sides of the plastic package 6, and one side of the pins, such as the third pin 24 and the fourth pin 25, are connected to the chip welding area 21 as a whole, as the pins of the drain of the chip 7, and the other side of the pins, such as the first pin 22 and the second pin 23, are isolated from each other and set with the chip welding area 21, respectively serving as the gate and source pins of the chip 7, and the chip 7 is connected to the first pin welding area 221 of the first pin 22 and the second pin welding area 231 of the second pin 23 through the bonding wire 8. The part of each pin exposed outside the plastic package 6 is bent away from the side where the chip welding area 21 is located, and the end of the pin and the back of the chip welding area 21 are located on the opposite sides of the plastic package 6. The end of the pin is used for welding on the PCB circuit board, and the end welding area of ​​each pin can be 100% covered by solder. The end of the pin is a plane, which is in the same plane position as the surface of the plastic package 6 or is set at a certain angle to the surface of the plastic package 6.

[0046] Based on the existing TO263, this embodiment realizes the position of the pins and the heat dissipation surface on different sides by reverse bending the pins, removes the PCB board from the system heat dissipation path, greatly reduces the overall thermal resistance, improves the heat dissipation performance of the device, increases the overall reliability of the system application, and is also beneficial to the wiring layout of the PCB board. This embodiment greatly increases the creepage distance between the device pins (the creepage distance between the D and S pins is increased from 1.27mm of the standard TO263 to 4mm) by moving the middle pin on the original three-pin side to the other side, and can be applied to higher voltage fields. At the same time, by widening the pin width of the D pole, the heat dissipation capacity of the device can also be improved to a certain extent. This packaging structure has good support strength.

[0047] Among them, the specific structure of the plastic package body 6 can refer to the existing TO263 products, for example, epoxy resin compression molding is used; the plastic package body 6 does not need to completely cover the frame, but can retain part of the frame structure exposed. For example, in the present invention, the pin part and the back of the heat dissipation surface expose the plastic package body 6, so that the pins maintain electrical connection with the outside world and contact with the radiator, so that the PAD exchanges heat with the outside world.

[0048] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A semiconductor lead frame, comprising a frame body (1), the frame body (1) being provided with a plurality of lead frame units (2), the lead frame units (2) being arranged in rows and columns, the lead frame units (2) comprising a chip welding area (21) and a plurality of pins, characterized in that: A plurality of the pins are arranged on opposite sides of the chip welding area (21), wherein the pins on one side are integrally connected to the chip welding area (21), and the pins on the other side are isolated from the chip welding area (21); The pins include a first pin (22), a second pin (23), a third pin (24) and a fourth pin (25); the first pin (22) and the second pin (23) are located on the same side of the chip welding area (21), namely, as side A; the first pin (22) and the second pin (23) are both isolated from the chip welding area (21); the third pin (24) and the fourth pin (25) are located on the same side of the chip welding area (21), namely, as side B; the side A and the side B are opposite sides of the chip welding area (21); the third pin (24) and the fourth pin (25) are respectively connected integrally to the chip welding area (21); The chip welding area (21) integrally extends out along the direction of the B side to form a top heat dissipation area (26), and the third pin (24) and the fourth pin (25) are respectively integrally connected to the top heat dissipation area (26); a first limiting hole (27) is provided at the top heat dissipation area (26), the center line of the first limiting hole (27) is located at the encapsulation line position, and the first limiting hole (27) is located between the third pin (24) and the fourth pin (25).

2. A semiconductor lead frame according to claim 1, characterized in that: The first pin (22) is provided with a first pin welding area (221), the second pin (23) is provided with a second pin welding area (231), and the connecting portion between the first pin (22) and the first pin welding area (221) and the connecting portion between the second pin (23) and the second pin welding area (231) are both provided with a groove and a second limiting hole (28).

3. A semiconductor lead frame according to claim 1, characterized in that: Two adjacent rows of lead frame units (2) are symmetrically arranged, and the two adjacent rows of lead frame units (2) are located on the B side and close to each other; the ends of the third pin (24) and the fourth pin (25) are both suspended, and a first connecting rib (3) is provided between the third pin (24) and the fourth pin (25), and the first connecting rib (3) longitudinally connects two adjacent chip welding areas (21).

4. A semiconductor lead frame according to claim 3, characterized in that: Second connecting ribs (4) are provided between adjacent first connecting ribs (3), and the second connecting ribs (4) are transversely connected to each of the first connecting ribs (3) and extend transversely to connect to the frame body (1).

5. A semiconductor lead frame according to any one of claims 1 to 4, characterized in that: Every two rows of the lead frame units (2) are arranged as a unit, and a flow channel (5) is provided between two adjacent chip welding areas (21) in the same unit.

6. A semiconductor lead frame according to any one of claims 1 to 4, characterized in that: Two rows and twenty columns of lead frame units (2) are arranged on the frame body (1); the frame body (1) has a length of 283.8±0.1 mm and a width of 50.24±0.1 mm.

7. A semiconductor lead frame according to any one of claims 1 to 4, characterized in that: The plane position where the chip welding area (21) is located is lower than the plane position where the isolated pins are located.

8. A semiconductor packaging structure, comprising a plastic package (6) and a lead frame unit (2), wherein the lead frame unit (2) comprises a chip welding area (21) and a plurality of pins connected to the chip welding area (21), the plastic package (6) covers the lead frame unit (2) and exposes the back side of the chip welding area (21) and a part of the structure of the pins, characterized in that: A plurality of pins are arranged on opposite sides of the plastic package (6), and the pins on one side are integrally connected to the chip welding area (21), and the pins on the other side are isolated from the chip welding area (21), and the portion of each pin exposed outside the plastic package (6) is bent away from the side where the chip welding area (21) is located, and the ends of the pins and the back of the chip welding area (21) are located on opposite sides of the plastic package (6), and the ends of the pins are used for welding on a PCB circuit board.

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