Low power lead frame

Abstract

The utility model discloses a low -power lead frame, including a plurality of parallelly arranged frame unit, and frame unit includes the slide area, and the upper side of slide area is equipped with with the fin, and the lower side of slide area is equipped with the welding part, and the welding part includes first soldering piece and second soldering piece, and first soldering piece is connected with left pin, and second soldering piece is connected with right pin, and the middle pin is equipped between left pin and right pin, and left pin, middle pin and right pin jointly connect with middle rib and lower rib, and the both sides of left pin, middle pin and right pin are equipped with the reinforcing rib of triangle structure. Through set up reinforcing rib and limit the width of reinforcing rib side edge, make the connecting area of pin and middle rib improve one time, improve the connecting strength of pin and middle rib on the basis of not affecting the package, avoid or reduce the fracture condition of pin this position, utilize the hypotenuse of reinforcing rib simultaneously, help epoxy resin betterly wrap frame, improve the consistency and insulating property of overall package.

Description

Technical Field

[0001] This utility model relates to the field of chip packaging technology, and more specifically, to a low-power lead frame. Background Technology

[0002] As a chip carrier for integrated circuits, the lead frame is a key structural component that uses bonding materials to achieve electrical connection between the internal circuit leads of the chip and the external leads, forming an electrical circuit. It acts as a bridge connecting to external wires, and most semiconductor integrated circuits require the use of lead frames.

[0003] In the prior art, invention patent CN203617283U discloses a low-power lead frame. This lead frame consists of multiple lead frame units arranged in a single row, interconnected by connecting ribs. Each lead frame unit includes a base and lead feet. The base has a carrier area with a circular indentation of 1.5 ± 0.02 mm in diameter. A circular hole is located in the center of the carrier area. Three lead feet are provided. The lead frame unit also has positioning holes. This frame is widely used in low-power energy-saving lamps and other electrical appliances. The 1.50 × 0.02 mm diameter indentation in the carrier area facilitates identification during bonding, thereby improving bonding speed.

[0004] Because the lead frame has a lead width of 0.72±0.02mm and a thickness of 0.5±0.01mm, and the lead is relatively thin, there is a possibility that the lead may break at the connection point with the center rib during the transfer and packaging process, which will affect the lead frame packaging.

[0005] Therefore, a new solution is needed to address the above problems. Utility Model Content

[0006] The purpose of this invention is to overcome the shortcomings of the prior art and provide a low-power lead frame.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] A low-power lead frame includes several parallel frame units. Each frame unit includes a carrier area, with a heat sink above the carrier area. The carrier area and the heat sink are integrated to form a single structure. A welding section is provided below the carrier area. The welding section includes a first welding piece and a second welding piece. The first welding piece is connected to a left lead, and the second welding piece is connected to a right lead. An intermediate lead is provided between the left and right leads and is connected to the carrier area. The left, intermediate, and right leads are of the same size and are connected to a central rib and a lower rib. Adjacent frame units are connected by the central and lower ribs. Both sides of the left, intermediate, and right leads are provided with triangular reinforcing ribs. The width of the side of the reinforcing rib used to connect to the central rib is half the width of the lead.

[0009] Furthermore, the pin width of the left pin, the middle pin, and the right pin is 0.6±0.05mm, the pin thickness of the left pin, the middle pin, and the right pin is 0.6±0.02mm, and the ends of the left pin, the middle pin, and the right pin maintain their respective pin widths and are connected to the lower rib.

[0010] Furthermore, the top of the heat sink has a U-shaped notch, and the side of the U-shaped notch is connected to the side of the heat sink and transitions in a trapezoidal shape.

[0011] Furthermore, the lower rib is provided with positioning holes, and each positioning hole corresponds to a frame unit.

[0012] Furthermore, the first and second welding pieces have the same structure, the left pin forms an angle of 65-80° with the first welding piece and the right pin forms an angle of 65-80° with the second welding piece, and the middle pin forms an angle of 65-80° with the carrier area.

[0013] Furthermore, gaps are provided between the first welding piece and the carrier area, and between the second welding piece and the carrier area.

[0014] The beneficial effects of this utility model are:

[0015] 1. In this utility model, triangular reinforcing ribs are provided on both sides of the left pin, the middle pin, and the right pin at the connection point of the central rib. By setting the reinforcing ribs and limiting the width of the side of the reinforcing ribs, the connection area between the pin and the central rib is doubled. Without affecting the packaging, the connection strength between the pin and the central rib is improved, avoiding or reducing the possibility of the pin breaking at this position, thereby improving the yield of the frame package. At the same time, the beveled side of the reinforcing ribs helps the epoxy resin to better wrap the frame, improving the overall packaging consistency and insulation performance.

[0016] 2. In this utility model, the ends of the left pin, the middle pin and the right pin maintain their respective pin widths and are connected to the lower rib to ensure the connection strength between the pin and the lower rib, and to avoid the pin breaking at this position and causing the pin to bend, thereby affecting the chip installation and frame packaging.

[0017] 3. In this utility model, a U-shaped notch is provided on the top of the heat sink, and the side of the U-shaped notch is connected to the side of the heat sink and transitions in a trapezoidal shape. During encapsulation, this can reduce the resistance to the flow of epoxy resin, avoid poor flow or stress concentration, improve the encapsulation quality and efficiency, and at the same time help the epoxy resin to better wrap the frame, improve the consistency of the encapsulation and the insulation performance. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of a low-power lead frame in this embodiment;

[0019] Figure 2 This is a schematic diagram of one structure of the frame unit in this embodiment;

[0020] Figure 3 for Figure 2 Enlarged view of section A;

[0021] Figure 4 This is a schematic diagram of a connection structure between the intermediate pin and the carrier area in this embodiment.

[0022] Reference numerals: Frame unit 1, Carrier area 11, Heat sink 12, U-shaped notch 121, First welding piece 13, Second welding piece 14, Left pin 15, Right pin 16, Middle pin 17, Reinforcing rib 18, Gap 19, Middle rib 2, Lower rib 3, Positioning hole 31. Detailed Implementation

[0023] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0024] Example: A low-power lead frame, such as Figures 1-4 As shown, it includes several parallel frame units 1, which are interconnected to form a lead frame. Each lead frame corresponds to a chip and is used in electrical devices with low power.

[0025] like Figure 2 and Figure 3As shown, the frame unit 1 includes a wafer carrier area 11 for mounting chips. A soldering section is provided below the wafer carrier area 11. The soldering section includes a first soldering piece 13 and a second soldering piece 14. The first soldering piece 13 and the second soldering piece 14 have the same structure. A gap 19 is provided between the first soldering piece 13 and the wafer carrier area 11, and between the second soldering piece 14 and the wafer carrier area 11. The first soldering piece 13 is connected to the chip mounted on the wafer carrier area 11 by bonding wires in a flying wire soldering manner. The second soldering piece 14 is connected to the chip mounted on the wafer carrier area 11 by bonding wires in a flying wire soldering manner.

[0026] By setting gaps 19 between the first solder pad 13 and the substrate area 11, and between the second solder pad 14 and the substrate area 11, firstly, the left pin 15, the right pin 16, and the middle pin 17 are electrically isolated from each other; secondly, during injection molding, epoxy resin fills this gap 19, forming a solid insulating barrier, increasing the creepage distance and electrical clearance 19 between the left and right pins 16 and the substrate area 11, while epoxy resin flows through the gap 19 to both sides of the middle pin 17, effectively encapsulating the middle pin 17.

[0027] Furthermore, such as Figure 2 As shown, the first solder pad 13 is connected to a left pin 15, the second solder pad 14 is connected to a right pin 16, and an intermediate pin 17 is provided between the left pin 15 and the right pin 16, which is connected to the substrate area 11. The left pin 15, the intermediate pin 17, and the right pin 16 have the same dimensions. Specifically, the pin width of the left pin 15, the intermediate pin 17, and the right pin 16 is 0.6±0.05mm, and the pin thickness of the left pin 15, the intermediate pin 17, and the right pin 16 is 0.6±0.02mm.

[0028] As a preferred option, such as Figure 2 As shown, left pin 15, middle pin 17, and right pin 16 are connected to a middle rib 2 and a lower rib 3. The middle rib 2 is located above the lower rib 3 and is connected to the upper parts of left pin 15, middle pin 17, and right pin 16. The lower rib 3 is connected to the ends of left pin 15, middle pin 17, and right pin 16. Meanwhile, adjacent frame units 1 are connected by the middle rib 2 and the lower rib 3. The purpose of setting the middle rib 2 and the lower rib 3 is twofold: first, to facilitate the connection of multiple frame units 1 into a whole, thus facilitating subsequent chip installation and packaging; and second, to constrain left pin 15, middle pin 17, and right pin 16, preventing pin bending during subsequent operations that could affect chip installation and frame packaging.

[0029] As a preferred option, such as Figure 4As shown, the left pin 15 forms an angle of 65-80° with the first solder pad 13, and the right pin 16 forms an angle of 65-80° with the second solder pad 14. The middle pin 17 forms an angle of 65-80° with the substrate area 11. This structure achieves several advantages: first, it shortens the distance between the solder pads and the chip solder joints, thus shortening the bonding wires, which have higher mechanical strength; second, the angle between the pins and the substrate area 11 facilitates epoxy resin flow, reducing the risk of turbulence or dead zones, thereby avoiding defects such as bubbles and material shortages caused by uneven filling; and third, the 65-80° angle reduces the bending amplitude during subsequent molding, disperses stress, and maintains the mechanical integrity of the pins.

[0030] Furthermore, such as Figure 2 As shown, triangular reinforcing ribs 18 are provided on both sides of the left pin 15, the middle pin 17, and the right pin 16 at the connection point of the central rib 2. The reinforcing rib 18 and the corresponding pin are integrated. The width of the side of the reinforcing rib 18 used to connect to the central rib 2 is half the width of the pin. By setting the reinforcing rib 18 and limiting the width of the side of the reinforcing rib 18, the connection area between the pin and the central rib 2 is doubled. Without affecting the package, the connection strength between the pin and the central rib 2 is improved, avoiding or reducing the possibility of pin breakage at this location, thereby improving the yield of the frame package. At the same time, the beveled edge of the reinforcing rib 18 helps the epoxy resin to better wrap the frame, improving the overall package consistency and insulation performance.

[0031] Preferably, the ends of the left pin 15, the middle pin 17, and the right pin 16 maintain their respective pin widths connected to the lower rib 3. Specifically, the pin width of the left pin 15 located between the middle rib 2 and the lower rib 3 remains constant from top to bottom; the pin width of the middle pin 17 located between the middle rib 2 and the lower rib 3 remains constant from top to bottom; and the pin width of the right pin 16 located between the middle rib 2 and the lower rib 3 remains constant from top to bottom. This design ensures the connection strength between the pins and the lower rib 3, preventing pin breakage and bending at this location, which could affect chip mounting and frame packaging.

[0032] As a preferred option, such as Figure 1 As shown, the lower rib 3 is provided with positioning holes 31, and each positioning hole 31 corresponds to a frame unit 1. By setting the positioning holes 31, the lead frame can be effectively positioned with the mold it uses; by setting multiple positioning holes 31, it can be ensured that the lead frame can still be effectively positioned with the mold it uses after one or more frame units 1 are removed.

[0033] Furthermore, such as Figure 2As shown, a heat sink 12 is provided above the substrate area 11, and the heat sink 12 is integrated with the substrate area 11 to form an integral structure. By providing the heat sink 12, heat dissipation of the chip mounted on the substrate area 11 is facilitated; by integrating the heat sink 12 with the substrate area 11 to form an integral structure, on the one hand, it facilitates rapid heat conduction; on the other hand, it ensures that all parts of the chip facing the substrate area 11 can contact the substrate area 11 and conduct heat, providing the maximum effective heat dissipation area and the lowest thermal resistance, thus improving the heat dissipation effect.

[0034] Preferably, the top of the heat sink 12 has a U-shaped notch 121, and the side of the U-shaped notch 121 is connected to the side of the heat sink 12 and transitions in a trapezoidal shape. With the above structure, the resistance to epoxy resin flow can be reduced during encapsulation, avoiding poor flow or stress concentration, improving encapsulation quality and efficiency, and at the same time helping the epoxy resin to better wrap the frame, improving the consistency and insulation performance of the encapsulation.

[0035] The above description is merely a preferred embodiment of this utility model. The protection scope of this utility model is not limited to the above embodiments. All technical solutions falling within the scope of this utility model's concept are protected. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principle of this utility model should also be considered within the protection scope of this utility model.

Claims

1. A low-power lead frame, comprising a plurality of parallel frame units (1), characterized in that, The frame unit (1) includes a substrate area (11), with a heat sink (12) above the substrate area (11). The substrate area (11) and the heat sink (12) are integrated to form an integral structure. A welding part is provided below the substrate area (11). The welding part includes a first welding piece (13) and a second welding piece (14). The first welding piece (13) is connected to a left pin (15), and the second welding piece (14) is connected to a right pin (16). An intermediate pin is provided between the left pin (15) and the right pin (16). (17) The middle pin (17) is connected to the substrate area (11). The left pin (15), the middle pin (17) and the right pin (16) are the same size and are connected to the middle rib (2) and the lower rib (3). Two adjacent frame units (1) are connected by the middle rib (2) and the lower rib (3). The left pin (15), the middle pin (17) and the right pin (16) are provided with reinforcing ribs (18) in a triangular structure on both sides. The width of the side of the reinforcing rib (18) used to connect the middle rib (2) is half the width of the pin.

2. A low-power lead frame according to claim 1, characterized in that, The pin width of the left pin (15), the middle pin (17) and the right pin (16) is 0.6±0.05mm, the pin thickness of the left pin (15), the middle pin (17) and the right pin (16) is 0.6±0.02mm, and the ends of the left pin (15), the middle pin (17) and the right pin (16) are connected to the lower rib (3) while maintaining their respective pin widths.

3. A low-power lead frame according to claim 1, characterized in that, The top of the heat sink (12) is provided with a U-shaped notch (121), and the side of the U-shaped notch (121) is connected to the side of the heat sink (12) and transitions in a trapezoidal shape.

4. A low-power lead frame according to claim 1, characterized in that, The lower rib (3) is provided with positioning holes (31), and each positioning hole (31) corresponds to a frame unit (1).

5. A low-power lead frame according to claim 1, characterized in that, The first welding piece (13) and the second welding piece (14) have the same structure. The left pin (15) forms an angle of 65-80° with the first welding piece (13) and the right pin (16) forms an angle of 65-80° with the second welding piece (14). The middle pin (17) forms an angle of 65-80° with the substrate area (11).

6. A low-power lead frame according to claim 1, characterized in that, A gap (19) is provided between the first welding piece (13) and the carrier area (11), and between the second welding piece (14) and the carrier area (11).

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