High-density TOLL lead frame structure

Abstract

The utility model provides a high-density TOLL lead frame structure, which comprises a rectangular lead frame and a plurality of lead frame units arranged on the lead frame in an array, each lead frame unit comprises a base island, a head part arranged on one side of the vertical direction of the base island and a foot part arranged on the other side of the vertical direction of the base island, the lead frame units in the adjacent rows are connected through connecting ribs, except for the two rows of lead frame units located at the topmost part and the bottommost part, the head parts of the lead frame units in each row are arranged opposite to the head parts of the adjacent lead frame units, and the foot parts of the lead frame units in each row are arranged opposite to the foot parts of the adjacent lead frame units; every four columns of lead frame units form an injection molding unit, in each injection molding unit, the first column of lead frame units and the second column of lead frame units are separated through a non-runner area, the second column of lead frame units and the third column of lead frame units are separated through a runner area, and the third column of lead frame units and the fourth column of lead frame units are separated through a non-runner area. By adopting the technical scheme of the utility model, the arrangement density of the lead frame units can be improved.

Description

Technical Field

[0001] The utility model relates to the field of integrated circuit packaging, and specifically to a high-density TOLL lead frame. Background Art

[0002] In the early stage, semiconductor packaging was mainly divided into two categories: integrated circuit packaging and discrete device packaging. With the development of industries such as power, automotive, and electric vehicles, power device packaging was derived from discrete device packaging. Especially in recent years, with the rapid development of the new energy industry, power device packaging products have also developed rapidly accordingly.

[0003] Currently, the main types of power device products include packaging forms such as TO220, TO220F, TO252, TO263, and TO247. Among them, due to the relatively thick encapsulation body and the limitations of the product structure itself, the TO263 package needs to further improve parameters such as heat dissipation performance, parasitic resistance, and on-resistance in actual applications to adapt to higher voltage, larger current, and higher power application scenarios. Therefore, a new TOLL package has emerged in the industry to replace packages such as TO263.

[0004] Compared with the TO-263-2L package, the size of the TOLL package is only 9.90mm x 11.68mm, the PCB board area is reduced by 25.5%, the height is reduced by 50%, and the circuit board space is reduced by 60%, making it more suitable for high-power density application scenarios. At the same time, compared with the TO-263-2L package, the source solder contact area of the TOLL package is increased by 4 times, thereby reducing the current density and avoiding electromigration caused by high current and temperature. Its excellent heat dissipation performance brings excellent temperature rise performance and improves the reliability of the product. Currently, the arrangement structures of the lead frames of TOLL package products are mainly 4 rows and 6 rows, and the outer dimensions and the number of products per strip are 80 pieces / strip with a width of 59.5mm x a length of 260mm and 132 pieces / strip with a width of 83mm x a length of 299.2mm respectively. Content of the Utility Model

[0005] The purpose of the utility model is to provide a high-density TOLL lead frame to further improve the product density and material utilization rate of the TOLL package lead frame.

[0006] In an embodiment of the present utility model, a high-density TOLL lead frame structure is provided, which includes: a rectangular lead frame and a plurality of lead frame units arranged in an array on the lead frame. Each lead frame unit includes a base island, a head provided on one side of the base island in the up-down direction, and a foot provided on the other side of the base island in the up-down direction. Adjacent rows of lead frame units are connected by connecting ribs. Except for the topmost and bottommost two rows of lead frame units, the heads of each row of lead frame units are arranged opposite to the heads of the adjacent lead frame units, and the feet of each row of lead frame units are arranged opposite to the feet of the adjacent lead frame units according to the situation. Every four columns of lead frame units form an injection molding unit. In each injection molding unit, the first column and the second column of lead frame units are separated by a non-runner area, the second column and the third column of lead frame units are separated by a main runner area, and the third column and the fourth column of lead frame units are separated by a non-runner area. The width of the non-runner area is smaller than the width of the main runner area, and the width of the connecting rib between the feet is smaller than the width of the connecting rib between the heads.

[0007] In an embodiment of the present utility model, a plurality of stress relief grooves corresponding to the lead frame units and runner removal holes provided between the stress relief grooves are provided in the main runner area.

[0008] In an embodiment of the present utility model, a plurality of square grooves are provided in the connecting rib between two rows of lead frame units with opposite feet.

[0009] In an embodiment of the present utility model, the width of the main runner area is 3.0 mm - 3.9 mm.

[0010] In an embodiment of the present utility model, the width of the non-runner area is 1.0 mm - 1.3 mm.

[0011] In an embodiment of the present utility model, the width of the connecting rib between two rows of lead frame units with opposite heads is 1.88 mm - 2.18 mm.

[0012] In an embodiment of the present utility model, the width of the connecting rib between two rows of lead frame units with opposite feet is 0.48 mm - 0.60 mm.

[0013] In an embodiment of the present utility model, the arrangement structure of the lead frame units on the lead frame is 8 rows and 24 columns.

[0014] Compared with the prior art, in the high-density TOLL lead frame structure of the present utility model, in each injection unit, the first column and the second column of lead frame units are separated by a non-runner area, the second column and the third column of lead frame units are separated by a runner area, and the third column and the fourth column of lead frame units are separated by a non-runner area. The width of the non-runner area is smaller than the width of the runner area, and the width of the connecting rib between the feet is smaller than the width of the connecting rib between the heads, so that the arrangement density of the lead frame units on the lead frame can be increased, and more lead frame units can be arranged within the limited space of the lead frame, which can further improve the material utilization rate and the equipment production efficiency. Brief Description of the Drawings

[0015] Figure 1 is a schematic structural diagram of the high-density TOLL lead frame structure according to an embodiment of the present utility model.

[0016] Figure 2 is a partial schematic diagram of the high-density TOLL lead frame structure according to an embodiment of the present utility model. Detailed Embodiment

[0017] In order to make the objectives, technical solutions and advantages of the present utility model clearer, the present utility model will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present utility model and are not used to limit the present utility model.

[0018] The implementation of the present utility model will be described in detail below with reference to specific embodiments.

[0019] As Figure 1 and Figure 2 shown, in an embodiment of the present utility model, a high-density TOLL lead frame structure is provided, which includes a rectangular lead frame 1 and a plurality of lead frame units 2 arranged in an array on the lead frame 1. In this embodiment, the arrangement structure of the lead frame units 2 on the lead frame 1 is 8 rows and 24 columns.

[0020] Every four columns of lead frame units 2 form an injection unit 3. In each injection unit 3, the first column and the second column of lead frame units 2 are separated by a non-runner area 4, the second column and the third column of lead frame units are separated by a main runner area 5, and the third column and the fourth column of lead frame units are separated by a non-runner area 4. The width of the non-runner area 4 is smaller than the width of the main runner area 5. Specifically, in this embodiment, the width of the main runner area is 3.0 mm - 3.9 mm, and the width of the non-runner area is 1.0 mm - 1.3 mm. By setting like this, the arrangement density of the lead frame units 2 on the lead frame 1 can be increased.

[0021] Furthermore, a plurality of stress relief grooves 51 corresponding to the lead frame units 2 and runner removal holes 52 disposed between the stress relief grooves 51 are provided in the main runner region 5. The stress relief grooves 51 play a role in stress relief during the stamping process of the lead frame 1, and the runner removal holes 52 play a role in removing residual glue in the runner after the product is injection molded.

[0022] As Figure 2 shown, each lead frame unit 2 includes a base island 21, a head (i.e., the end close to the heat sink, which is commonly named the head in the industry) 22 disposed on one side in the up and down direction of the base island, and a foot 23 disposed on the other side in the up and down direction of the base island 21. It should be noted that the adjacent rows of lead frame units 2 are connected by connecting ribs 6. Except for the topmost and bottommost rows of lead frame units 2, the heads 22 of each row of lead frame units 2 are oppositely arranged with the heads 22 of the adjacent lead frame units 2, and the feet 23 of each row of lead frame units 2 are oppositely arranged with the feet 23 of the adjacent lead frame units 2. The width of the connecting rib 6 between the feet 23 is smaller than the width of the connecting rib 6 between the heads 22. Specifically, in the embodiment of the present invention, the width of the connecting rib 6 between the two rows of lead frame units 2 with opposite heads 22 is 1.88 mm - 2.18 mm, and the width of the connecting rib 6 between the two rows of lead frame units 2 with opposite feet 23 is 0.48 mm - 0.60 mm. By such an arrangement, the arrangement density of the lead frame units 2 on the lead frame 1 can be further increased.

[0023] Furthermore, a plurality of square grooves 61 are provided in the connecting rib 6 between the two rows of lead frame units 2 with opposite feet, which can save the frame material and is also convenient for cutting.

[0024] In summary, by adopting the high-density TOLL lead frame structure of the present invention, in each injection unit, the first column and the second column of lead frame units are separated by a non-runner region, the second column and the third column of lead frame units are separated by a runner region, the third column and the fourth column of lead frame units are separated by a non-runner region, the width of the non-runner region is smaller than the width of the runner region, and the width of the connecting rib between the feet is smaller than the width of the connecting rib between the heads, so that the arrangement density of the lead frame units on the lead frame can be increased, more lead frame units can be arranged in the limited lead frame space, and the material utilization rate and the equipment production efficiency can be further improved.

[0025] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A high-density TOLL lead frame structure, characterized in that: include: A rectangular lead frame and a plurality of lead frame units arranged in an array on the lead frame, each lead frame unit comprising a base island, a head arranged on one side of the base island in the up-down direction, and a foot arranged on the other side of the base island in the up-down direction, adjacent rows of lead frame units are connected by connecting ribs, except for the two rows of lead frame units located at the top and the bottom, the heads of the lead frame units in each row are arranged opposite to the heads of the lead frame units adjacent thereto, and the feet of the lead frame units in each row are arranged opposite to the feet of the lead frame units adjacent thereto, and every four columns of lead frame units constitute an injection molding unit, and in each injection molding unit, the first column and the second column of lead frame units are separated by a non-flow channel area, the second column and the third column of lead frame units are separated by a main flow channel area, and the third column and the fourth column of lead frame units are separated by a non-flow channel area, the width of the non-flow channel area is smaller than the width of the main flow channel area, and the width of the connecting ribs between the feet is smaller than the width of the connecting ribs between the heads.

2. The high-density TOLL lead frame structure according to claim 1, characterized in that: The main flow channel region is provided with a plurality of stress release grooves corresponding to the lead frame units and de-flow channel holes provided between the stress release grooves.

3. The high-density TOLL lead frame structure according to claim 1, characterized in that: A plurality of square grooves are arranged in the connecting rib between two rows of lead frame units opposite to each other at the foot portions.

4. The high-density TOLL lead frame structure according to claim 1, characterized in that: The width of the main channel area is 3.0 mm-3.9 mm.

5. The high-density TOLL lead frame structure according to claim 1, characterized in that: The width of the non-flow channel area is 1.0 mm-1.3 mm.

6. The high-density TOLL lead frame structure according to claim 1, characterized in that: The width of the connecting ribs between the heads is 1.88 mm to 2.18 mm.

7. The high-density TOLL lead frame structure according to claim 1, characterized in that: The width of the connecting ribs between the legs is 0.48 mm to 0.60 mm.

8. The high-density TOLL lead frame structure according to claim 1, characterized in that: The arrangement structure of the lead frame units on the lead frame is 8 rows and 24 columns.

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