High-density lead frame for packaging discrete semiconductor device

Abstract

The utility model provides a high-density lead frame for packaging discrete semiconductor devices, which relates to the technical field of lead frames, and comprises a plurality of packaging assemblies, each packaging assembly comprises an outer lead, an inner lead and a base island, the surface of each base island is provided with a heat dissipation structure, the heat dissipation structure covers the upper surface of the base island, the heat dissipation structure is a silver plating layer, and the silver plating layer covers the outer lead. The heat dissipation structure is arranged on the surface of the base island, when a worker places a semiconductor chip on the surface of the base island, after long-term work and the temperature of the surface of the semiconductor chip is too high, the heat conduction efficiency can be improved by arranging the heat dissipation structure which is a silver coating, and silver plating can be achieved, so that the contact thermal resistance is reduced; the heat dissipation holes are formed in the surface of the flip cover, so that heat can be quickly diffused to the outside through the heat dissipation holes, and the service life of the semiconductor chip is prolonged.

Description

Technical Field

[0001] The utility model relates to a high-density lead frame for semiconductor discrete device packaging, belonging to the technical field of lead frames. Background Art

[0002] As a chip carrier for integrated circuits, a lead frame is a key structural component that realizes the electrical connection between the internal circuit leads of a chip and the external leads through bonding materials (gold wires, aluminum wires, copper wires) to form an electrical loop, playing a role as a bridge connecting to external wires. In the existing integrated circuit lead frame packaging technology, since the lead frame, bonding material, plating layer, and plastic encapsulation material are made of different materials respectively, the thermal expansion coefficients of these materials are also different.

[0003] The existing patent publication number is CN203521401U, which discloses a high-density lead frame for semiconductor discrete device packaging. It includes several packaging units, and each packaging unit includes external leads, internal leads, base island connecting ribs, and a base island. One end of the internal lead and one end of the base island connecting rib are both connected to the external lead, and the other end of the internal lead and the other end of the base island connecting rib are both connected to the base island. The utility model improves the bonding strength between the lead frame, bonding material, and plastic encapsulation material, thereby improving the use reliability and quality of the product.

[0004] For the high-density lead frames used in existing semiconductors, the semiconductor chips are usually covered to fix them. However, due to the surface temperature of the semiconductor chips rising during long-term operation after being covered, if heat is not dissipated in time, it will lead to high-temperature overload of the semiconductor chips, affecting the service life of the semiconductor chips. Summary of the Utility Model

[0005] The purpose of the utility model is to solve the problem that for the high-density lead frames used in existing semiconductors, the semiconductor chips are usually covered to fix them. However, due to the surface temperature of the semiconductor chips rising during long-term operation after being covered, if heat is not dissipated in time, it will lead to high-temperature overload of the semiconductor chips, affecting the service life of the semiconductor chips, and to propose a high-density lead frame for semiconductor discrete device packaging.

[0006] To achieve the above purpose, the utility model adopts the following technical scheme: A high-density lead frame for semiconductor discrete device packaging includes a plurality of packaging components. Each packaging component includes external leads, internal leads, and a base island. A heat dissipation structure is provided on the surface of the base island, and the heat dissipation structure covers the upper surface of the base island. The heat dissipation structure is a silver plating layer.

[0007] Preferably, the external leads are fixedly connected to the bottom of the internal leads, and the top of the internal leads is fixedly connected to the bottom of the base island.

[0008] Preferably, a plurality of longitudinal ribs are fixedly installed between adjacent encapsulation components, and a plurality of through holes are formed on the surface of each longitudinal rib.

[0009] Preferably, pins are fixedly installed on both the left and right sides of each base island, and the pins are located on top of the inner leads.

[0010] Preferably, a flip cover is movably hinged on the top of each base island, circular heat dissipation holes are formed on the surface of the flip cover, and the flip cover covers the surface of the base island.

[0011] Preferably, a middle rib foot is fixedly installed in the middle of each longitudinal rib, and a connecting rib is fixedly installed between the base island and the longitudinal rib.

[0012] Compared with the prior art, the advantages and positive effects of the present utility model are as follows.

[0013] 1. In the present utility model, a heat dissipation structure is provided on the surface of the base island. After the semiconductor chip is placed on the surface of the base island by the staff and undergoes long-term operation, when the temperature on the surface of the semiconductor chip is too high, through the setting of the heat dissipation structure, and the heat dissipation structure is a silver plating layer, silver plating can improve the efficiency of heat conduction, thereby reducing the contact thermal resistance. By providing heat dissipation holes on the surface of the flip cover, the heat can be quickly diffused to the outside through the heat dissipation holes, thus extending the service life of the semiconductor chip.

[0014] 2. In the present utility model, by providing longitudinal ribs and fixedly installing a connecting rib between the base island and the longitudinal ribs, the stability of the overall lead frame is improved, the durability of the lead frame is enhanced, and at the same time, the density of the lead frame is greatly increased. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The drawings are used to provide a further understanding of the present utility model, and constitute a part of the specification. Together with the specific embodiments of the present utility model, they are used to explain the present utility model, and do not constitute a limitation to the present utility model.

[0016] Figure 1 It is a schematic diagram of the separated three-dimensional structure of a high-density lead frame for semiconductor discrete device packaging proposed by the present utility model;

[0017] Figure 2 It is for the high-density lead frame for semiconductor discrete device packaging proposed by the present utility model Figure 1 The enlarged schematic diagram of the structure at A;

[0018] Figure 3 It is a partial structure schematic diagram of a high-density lead frame for semiconductor discrete device packaging proposed by the present utility model;

[0019] Figure 4This is a partial structural schematic diagram of a high-density lead frame for semiconductor discrete device packaging proposed by the present utility model.

[0020] Legend: 1. Encapsulation component; 2. Outer lead; 3. Inner lead; 4. Base island; 5. Heat dissipation structure; 6. Longitudinal rib; 7. Through hole; 8. Pin; 9. Flip cover; 10. Heat dissipation hole; 11. Middle rib foot; 12. Connecting rib. Specific embodiments

[0021] In order to more clearly understand the above-mentioned objects, features and advantages of the present utility model, the present utility model will be further described below with reference to the drawings and embodiments. It should be noted that, without conflict, the embodiments of the present application and the features in the embodiments can be combined with each other.

[0022] In the following description, many specific details are set forth in order to fully understand the present utility model. However, the present utility model can also be implemented in other ways different from those described herein. Therefore, the present utility model is not limited by the specific embodiments disclosed in the following specification.

[0023] Embodiment 1

[0024] As Figures 1-4 shown, the present utility model provides a technical solution: a high-density lead frame for semiconductor discrete device packaging, including a plurality of encapsulation components 1. Each encapsulation component 1 includes an outer lead 2, an inner lead 3 and a base island 4. A heat dissipation structure 5 is provided on the surface of the base island 4. The heat dissipation structure 5 covers the upper surface of the base island 4. The heat dissipation structure 5 is a silver plating layer. Specifically: Silver plating has a certain influence on the contact thermal resistance. Silver plating can improve the efficiency of heat conduction, thereby reducing the contact thermal resistance. The surface of silver plating is very smooth and has good thermal conductivity. When there is an oxide layer, an air layer or other pollutants on the contact surface of two objects, it will lead to an increase in the contact thermal resistance and reduce the heat conduction efficiency. Silver plating can effectively improve the situation of the contact surface and improve the heat transfer efficiency. It can form good contact with other metals or materials to provide better thermal contact.

[0025] The outer lead 2 is fixedly connected to the bottom of the inner lead 3, and the top of the inner lead 3 is fixedly connected to the bottom of the base island 4.

[0026] Pins 8 are fixedly installed on both the left and right sides of each base island 4. The pins 8 are located at the top of the inner lead 3.

[0027] A flip cover 9 is movably hinged on the top of each base island 4. Circular heat dissipation holes 10 are formed on the surface of the flip cover 9, and the flip cover 9 covers the surface of the base island 4.

[0028] In this embodiment, a heat dissipation structure 5 is provided on the surface of the base island 4. After the semiconductor chip is placed on the surface of the base island 4 by the staff and undergoes long-term operation, the surface temperature of the semiconductor chip becomes too high. By providing the heat dissipation structure 5, and the heat dissipation structure 5 is a silver-plated layer, silver plating can improve the efficiency of heat conduction, thereby reducing the contact thermal resistance. By providing heat dissipation holes 10 on the surface of the flip cover 9, the heat can be quickly diffused to the outside through the heat dissipation holes 10, thereby extending the service life of the semiconductor chip.

[0029] Embodiment 2

[0030] As Figures 1-4 shown, a plurality of longitudinal ribs 6 are fixedly installed between adjacent packaging components 1, and a plurality of through holes 7 are provided on the surface of each longitudinal rib 6.

[0031] A middle rib foot 11 is fixedly installed in the middle of each longitudinal rib 6, and a connecting rib 12 is fixedly installed between the base island 4 and the longitudinal rib 6.

[0032] In this embodiment, by providing the longitudinal ribs 6 and fixedly installing a connecting rib 12 between the base island 4 and the longitudinal ribs 6, the stability of the overall lead frame is improved, the durability of the lead frame is enhanced, and at the same time, the density of the lead frame is greatly increased.

[0033] The working principle of this embodiment: During use, first, a heat dissipation structure 5 is provided on the surface of the base island 4. After the semiconductor chip is placed on the surface of the base island 4 by the staff and undergoes long-term operation, the surface temperature of the semiconductor chip becomes too high. By providing the heat dissipation structure 5, and the heat dissipation structure 5 is a silver-plated layer, silver plating can improve the efficiency of heat conduction, thereby reducing the contact thermal resistance. By providing heat dissipation holes 10 on the surface of the flip cover 9, the heat can be quickly diffused to the outside through the heat dissipation holes 10. By providing the longitudinal ribs 6 and fixedly installing a connecting rib 12 between the base island 4 and the longitudinal ribs 6, the stability of the overall lead frame is improved, the durability of the lead frame is enhanced, and at the same time, the density of the lead frame is greatly increased.

[0034] The above are only the preferred embodiments of the present invention, and are not intended to limit the present invention in other forms. Any person skilled in the art may use the disclosed technical content to make changes or modifications into equivalent embodiments with equivalent changes and apply them to other fields. However, as long as the technical content of the present invention is not departed from, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention still belong to the protection scope of the technical solution of the present invention.

Claims

1. A high-density lead frame for semiconductor discrete device packaging, characterized in that: It includes a plurality of encapsulation components (1), each of the encapsulation components (1) includes an external lead (2), an internal lead (3) and a base island (4), a heat dissipation structure (5) is provided on the surface of the base island (4), the heat dissipation structure (5) covers the upper surface of the base island (4), and the heat dissipation structure (5) is a silver-plated layer.

2. The high-density lead frame for semiconductor discrete device packaging according to claim 1, characterized in that: The external lead (2) is fixedly connected to the bottom of the internal lead (3), and the top of the internal lead (3) is fixedly connected to the bottom of the base island (4).

3. The high-density lead frame for semiconductor discrete device packaging according to claim 1, characterized in that: A plurality of longitudinal ribs (6) are fixedly installed between adjacent encapsulation components (1), and a plurality of through holes (7) are formed on the surface of each longitudinal rib (6).

4. The high-density lead frame for semiconductor discrete device packaging according to claim 1, wherein: Pins (8) are fixedly installed on both the left and right sides of each base island (4), and the pins (8) are located at the top of the internal lead (3).

5. The high-density lead frame for semiconductor discrete device packaging according to claim 1, wherein: A flip cover (9) is movably hinged to the top of each base island (4), circular heat dissipation holes (10) are formed on the surface of the flip cover (9), and the flip cover (9) covers the surface of the base island (4).

6. The high-density lead frame for semiconductor discrete device packaging according to claim 3, wherein: A middle rib foot (11) is fixedly installed in the middle of each longitudinal rib (6), and a connecting rib (12) is fixedly installed between the base island (4) and the longitudinal rib (6).

Images