QFN lead frame and packaging module

Abstract

The QFN lead frame comprises a plurality of frame units arranged on a frame body in an array mode, each frame unit comprises a base island arranged in the middle area of the frame unit and a plurality of pins arranged on the periphery of the base island at intervals, the side edges of the base islands and the side edges of the frame units are arranged in a preset included angle mode, and the base islands are connected with the frame body through base island connecting ribs. The base island connecting ribs correspond to the vertex angles of the base island in position. Each side of the frame unit is provided with two pins, and the two pins located on the same side of the frame unit respectively correspond to two adjacent side edges of the base island. The back of the frame unit is provided with radiating fins corresponding to the base islands and a semi-etching area wrapping the peripheries of the radiating fins. According to the scheme, the layout of the base islands and the pins is improved, under the condition that the preset number of the pins is met, it is guaranteed that the area of the base islands and the pins are larger, the bonding effectiveness in packaging is guaranteed, the heat dissipation effect of the packaging module is improved, the risk of product layering is reduced through the half-etching design, and the packaging module is suitable for packaging with the high requirement for the chip occupied area.

Description

Technical Field

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

[0002] Due to the rapid development of electronic technology, the requirement for the integration degree of products has increased, and the board area occupied by a single chip is required to be smaller and smaller. For traditional DIP and SOP series packaging forms, the board area is large and gradually cannot meet the requirements of the market. For example, for LED chips, the development trend requires them to have a smaller volume, higher stability and heat dissipation performance, so it is necessary to improve the existing chip packaging structure. The packaging effect of the chip involves aspects such as the design and layout of the lead frame, as well as the packaging process means and electrical connection methods based on the lead frame. Therefore, if we want to reduce the board area occupied by the packaged chip while improving the heat dissipation and electrical performance of the product, we can start the research from the improvement of the lead frame. Summary of the Utility Model

[0003] To solve the deficiencies of the above-mentioned related prior art, the utility model provides a QFN lead frame and a packaging module, which improve the layout of the base island and pins, so as to ensure that the area of the base island and the pins are larger while meeting the predetermined number of pins, so as to ensure the bonding effectiveness in packaging and improve the heat dissipation effect of the packaging module.

[0004] To achieve the purpose of the utility model, the following scheme is proposed:

[0005] A QFN lead frame includes a plurality of frame units arranged in an array on a frame body. Each frame unit includes a base island arranged in the middle area of the frame unit and a plurality of pins arranged at intervals around the base island. The side of the base island is arranged at a predetermined angle with the side of the frame unit, and the base island is connected to the frame body through a base island connecting rib.

[0006] Further, the side of the base island is arranged at a 45° angle with the side of the frame unit.

[0007] Further, the base island connecting rib corresponds to each vertex position of the base island.

[0008] Further, the number of pins on each side of the frame unit is the same. Further, there are 8 pins, and 2 pins are arranged on each side of the frame unit. The 2 pins located on the same side of the frame unit respectively correspond to two adjacent sides of the base island.

[0009] Further, the back of the frame unit has a heat sink corresponding to the base island and a semi-etching area wrapped around the heat sink.

[0010] Furthermore, at least part of the back of the base island connecting rib is correspondingly located in the semi-etching area.

[0011] Furthermore, at least a part of the back of the base island connecting rib corresponds to a non-half-etched area.

[0012] Furthermore, at least a part of at least one pin back is in the half-etched area.

[0013] Further, a chip pin1 mark is formed by half-etching one side of the base island.

[0014] A packaging module includes the frame unit of the QFN lead frame described above.

[0015] Advantages of the present utility model:

[0016] 1. By improving the layout of the base island and pins, when meeting the predetermined number of pins, it is possible to ensure a larger base island area and pin area within a limited packaging size, so as to ensure the bonding effectiveness in the packaging and improve the heat dissipation effect of the packaging module;

[0017] 2. When achieving the predetermined base island area, pin area and quantity layout, without expanding the packaging size, so that when using the same specification of the frame body, more frame units can be formed on the frame, improving the mass production rate;

[0018] 3. By setting the half-etched area, the delamination prevention ability is improved; preferably, by setting partial non-half-etched areas for the base island connecting ribs, the stability of the ground wire bonding is improved. Description of the Drawings

[0019] Figure 1 Shows a schematic front view of the frame unit of the embodiment of the present application.

[0020] Figure 2 Shows a schematic back view of the frame unit of the embodiment of the present application. Detailed Embodiments

[0021] To make the objectives, technical solutions, and advantages of the embodiments of the present utility model clearer, the following will describe the embodiments of the present utility model in detail with reference to the drawings. However, the described embodiments are only a part of the embodiments of the present utility model, rather than all of the embodiments.

[0022] In one aspect of the embodiments of the present application, a QFN lead frame is provided, as Figure 1 - Figure 2 shown, including a plurality of frame units 1 arranged in an array on the frame body. The frame unit 1 includes a base island 2 arranged in the middle area of the frame unit 1 and a plurality of pins 3 arranged at intervals around the base island 2. The side of the base island 2 and the side of the frame unit 1 are arranged at a predetermined angle. The base island 2 is connected to the frame body through a base island connecting rib 22. Specifically, the base island connecting rib 22 is connected to the corresponding vertex positions of the base island 2 and extends to the edge of the frame unit 1

[0023] By arranging the base island 2 at an inclined angle relative to the frame unit 1. For example, when the frame unit 1 is generally in a rectangular area as a whole and the base island 2 is rectangular as a whole, the side of the base island 2 forms a 45° angle with the side of the frame unit 1. This can form a base island 2 with a larger area within the limited area of the frame unit 1, and ensure that while the pins are evenly distributed on each side, there is also sufficient area, avoiding the problem that the bonding wires cannot be attached due to the small area of the base island and / or pins during small-size packaging. Thus, the stability and effectiveness of the wire bonding process in subsequent packaging can be maintained without increasing the packaging size.

[0024] The pins 3 have the same number on each side of the frame unit 1. Specifically, in this example, there are 8 pins 3, and 2 pins 3 are on each side of the frame unit 1. The 2 pins 3 located on the same side of the frame unit 1 respectively correspond to two adjacent sides of the base island 2. Thus, the spatial layout under the limited packaging size is reasonably utilized, enabling the pins 3 to be evenly distributed and maintaining sufficient bonding area for facilitating wire bonding.

[0025] As Figure 2 shown, the back of the frame unit 1 has a heat sink 6 corresponding to the base island 2 and a semi-etching area 4 wrapped around the periphery of the heat sink 6. By setting the heat sink 6, the heat dissipation effect of the base island 2 can be improved, taking advantage of the heat dissipation performance of the chip on the base island 2 after plastic encapsulation. Through the setting of the semi-etching area 4, the delamination risk of the packaged product can be reduced.

[0026] Preferably, at least part of the back of the base island connecting rib 22 is correspondingly located in the semi-etching area 4, and / or at least part of the area on the back of at least one pin 3 is in the semi-etching area 4, which can provide delamination prevention ability after packaging.

[0027] Preferably, at least part of the back of the base island connecting rib 22 correspondingly has a non-semi-etching area 5, which is used to prevent poor operation stability during ground wire bonding and improve the stability of ground wire bonding.

[0028] Preferably, specifically, optionally, in order to facilitate confirming the chip direction during die bonding, a chip pin 1 mark 21 is formed by semi-etching inside one side of the base island 2, and its shape can be semi-circular, chamfered, etc., without being limited by the shape.

[0029] On the other hand, an embodiment of the present application provides a packaging module obtained by packaging using the QFN lead frame described in the previous embodiment. The packaging module includes a plastic package body and a frame unit wrapped in the plastic package body, and a chip is arranged on the base island.

[0030] In this example, through the special layout of the base island and pins, the size of the base island is maximally increased, the compatible chip size is increased, and a prerequisite basis is provided for using lower-cost materials for product packaging.

[0031] The above are only the preferred embodiments of the present utility model, and do not represent the only or limit the present utility model. Those skilled in the art should understand that various changes or equivalent substitutions made to the present utility model without departing from the scope of the present utility model all fall within the scope of protection of the present utility model.

Claims

1. A QFN lead frame, comprising a plurality of frame units (1) arranged in an array on a frame body, characterized in that: The frame unit (1) comprises a base island (2) arranged in the middle area of ​​the frame unit (1) and a plurality of pins (3) arranged at intervals on the periphery of the base island (2); the side of the base island (2) and the side of the frame unit (1) are arranged at a predetermined angle; the base island (2) is connected to the frame body via a base island connecting rib (22).

2. The QFN lead frame according to claim 1, characterized in that: The side edge of the base island (2) and the side edge of the frame unit (1) are arranged at an angle of 45°.

3. The QFN lead frame according to claim 1, characterized in that: The base island connecting ribs (22) correspond to the positions of the top corners of the base island (2).

4. The QFN lead frame according to claim 2, characterized in that: The pins (3) have the same number on each side of the frame unit (1).

5. The QFN lead frame according to claim 4, characterized in that: There are 8 pins (3), 2 on each side of the frame unit (1), and the two pins (3) located on the same side of the frame unit (1) correspond to two adjacent sides of the base island (2).

6. The QFN lead frame according to claim 1, characterized in that: The back of the frame unit (1) has a heat sink (6) corresponding to the base island (2) and a half-etched area (4) wrapped around the periphery of the heat sink (6).

7. The QFN lead frame according to claim 6, characterized in that: At least a portion of the back of the base island connecting rib (22) is correspondingly located in the half-etched area (4).

8. The QFN lead frame according to claim 6, characterized in that: At least part of the back of the base island connecting rib (22) corresponds to a non-half-etched area (5).

9. The QFN lead frame according to claim 6, characterized in that: At least a portion of the back of at least one lead (3) is located in the half-etched region (4).

10. A packaging module, characterized in that: A frame unit (1) comprising a QFN lead frame as claimed in any one of claims 1 to 9.

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