A copper clip structure suitable for large size chip stack package

Abstract

The utility model discloses a copper clamp structure suitable for large size chip stack package, include: copper clamp body, copper clamp body includes the first soldering tin section, the bending section and the second soldering tin section that connect gradually, is equipped with half etching groove on the bending section, and the both sides bottom wall of half etching groove has a convex part respectively. Through the application of the utility model, a copper clamp structure suitable for large size chip stack package is provided, which can realize the stack packaging of large size chips under the condition of adopting a stamping lead frame. Compared with the deformation problem of traditional etching lead frame when increasing the packaging size, the copper clamp structure can adapt to larger packaging size by cooperating with the stamping lead frame, thereby improving the output current capacity of the package. In addition, the copper clamp structure sets the avoidance distance and the impression groove, so that the bending section still has sufficient strength after bending processing operation.

Description

Technical Field

[0001] This utility model relates to the field of semiconductor packaging technology, and in particular to a copper clip structure suitable for large-size chip stacking packaging. Background Technology

[0002] With the current trend towards lighter, thinner, shorter, and smaller electronic products, higher demands are being placed on semiconductor packaging technology. Achieving higher power density within a limited space has become a key objective, requiring packaging solutions to deliver higher current without changing the package size. However, high current inevitably increases chip heat loss, leading to a rise in chip junction temperature and consequently shortening the chip's lifespan.

[0003] To address this practical problem, stacked chip packaging solutions have emerged. However, existing stacked packaging solutions still have significant limitations: from a cost perspective, etched lead frames account for a large proportion of the packaging material BOM cost, and are more expensive than stamped lead frames; from an application demand perspective, with the increasing demand for high-power applications, the need to increase package size to accommodate larger chips and improve output current capability is becoming increasingly urgent. However, etched lead frames are typically thin, and if the package size is increased, thin etched lead frames may experience manufacturing problems such as twisting and deformation during the packaging process. Stamped frames, on the other hand, can be made from thicker materials, have higher strength, and can be used for larger package sizes. Therefore, using stamped lead frames instead of etched lead frames can solve these limitations. However, at the same time, corresponding improvements to the copper clip structure are also needed. Utility Model Content

[0004] In view of this, in order to solve the above problems, the purpose of this utility model is to provide a copper clip structure suitable for large-size chip stacking packaging, including: a copper clip body, the copper clip body including a first solder section, a bending section and a second solder section connected in sequence, the bending section having a semi-etched groove, and the bottom walls on both sides of the semi-etched groove having a protrusion respectively.

[0005] In another preferred embodiment, the end surface of the protrusion away from the sidewall of the semi-etched groove forms a clearance distance with the sidewall of the semi-etched groove.

[0006] In another preferred embodiment, an imprinting groove is formed on the bottom wall of the semi-etched tank at a position between the two protrusions.

[0007] In another preferred embodiment, the first solder segment and the second solder segment have the same thickness, and the thickness of the bent segment is less than the thickness of the first solder segment and the second solder segment.

[0008] In another preferred embodiment, two stress relief grooves are provided on the bending section, and the two stress relief grooves are arranged in parallel.

[0009] In another preferred embodiment, one end of the stress relief groove extends to the first solder section, and the other end of the stress relief groove extends to the second solder section.

[0010] In another preferred embodiment, a groove is provided on the side of the second solder section away from the bent section.

[0011] In another preferred embodiment, the thickness of the first solder segment and the second solder segment is 0.25 mm.

[0012] In another preferred embodiment, the first solder segment includes a first horizontal segment, an inclined segment, and a second horizontal segment connected in sequence, one side of the bent segment is connected to the second horizontal segment, and the lower end of the first horizontal segment is connected to the external lead frame through a first solder layer.

[0013] In another preferred embodiment, the second solder segment includes a third horizontal segment, the other side of the bent segment is connected to one side of the third horizontal segment, the lower end of the third horizontal segment can be connected to an external first chip through a second solder layer, and the upper end of the third horizontal segment can be connected to an external second chip through a third solder layer.

[0014] The present invention, by adopting the above-mentioned technical solution, has the following positive effects compared with the prior art: By applying the present invention, a copper clip structure suitable for large-size chip stacking packaging is proposed. This copper clip structure enables the stacking packaging of large-size chips even when using a stamped lead frame. Compared with the deformation problem that easily occurs when the package size is increased by traditional etched lead frames, this copper clip structure, in conjunction with the stamped lead frame, can adapt to larger package sizes, thereby improving the output current capability of the package. Furthermore, by setting avoidance distances and imprinted grooves, the copper clip structure ensures that the bent section still has sufficient strength after bending operations, thus helping to avoid problems such as poor chip connection or electrical performance damage caused by deformation of the copper clip body, and helping to ensure the structural stability of the package. Attached Figure Description

[0015] Fig. 1 This is a schematic diagram of a copper clip structure suitable for large-size chip stacking packaging according to the present invention;

[0016] Fig. 2 This is a schematic diagram of the bent section of a copper clip structure suitable for large-size chip stacking packaging according to this utility model;

[0017] Fig. 3 This is a diagram illustrating the usage state of a copper clip structure suitable for large-size chip stacking and packaging according to this utility model.

[0018] In the attached image:

[0019] 1. First solder section; 2. Bending section; 3. Second solder section; 21. Semi-etched groove; 22. Protrusion; 23. Stress relief groove; 31. Groove. Detailed Implementation

[0020] The technical solution of this utility model will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0021] In the description of this utility model, it should be understood that the orientation or positional relationship indicated by terms such as "upper", "lower", "left", "right", "inner", "outer", "front", "back", "horizontal", and "vertical" are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model, and are not intended to indicate or imply that the device or component referred to must have a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0022] It should be noted that the terms "horizontal" and "vertical" in this utility model are used to describe approximate positional relationships, and not strictly "horizontal plane" or "vertical plane".

[0023] like Figs. 1-3 As shown, a preferred embodiment of a copper clip structure suitable for large-size chip stacking packaging is illustrated, comprising: a copper clip body, the copper clip body including a first solder section 1, a bending section 2 and a second solder section 3 connected in sequence, the bending section 2 having a semi-etched groove 21, the semi-etched groove 21 can provide sufficient insulation distance for the second chip, thereby helping to avoid electrical short circuits and other problems of the second chip, and ensuring the stability of the internal electrical performance of the package, and each of the two bottom walls of the semi-etched groove 21 has a protrusion 22.

[0024] Furthermore, as a preferred embodiment, a clearance distance is formed between the end surface of the protrusion 22 away from the sidewall of the semi-etched groove 21 and the sidewall of the semi-etched groove 21. Furthermore, during the manufacture of the copper clip body, when the bending segment 2 is bent using a bending die, the punch in the bending die will fit against the bottom wall of the semi-etched groove 21 located between the two protrusions 22, and then the punch can clamp and compact the bending segment 2, so that the bending segment 2 can achieve better dimensional accuracy in the presence of the semi-etched groove 21.

[0025] Furthermore, in a preferred embodiment, an imprinting groove is formed on the bottom wall of the semi-etched groove 21 at a position between the two protrusions 22, and the imprinting groove is connected to the semi-etched groove 21. Furthermore, during the bending operation of the bending segment 2, the punch can clamp and compact the bottom wall of the imprinting groove. Under the pressure of the punch, a certain imprinting depth is generated at the imprinting groove, and the imprinting depth is the same as the vertical height of the protrusions 22. This helps to further optimize the forming effect of the bending segment 2, making the bending angle and shape more precise.

[0026] Furthermore, in a preferred embodiment, the first solder segment 1 and the second solder segment 3 have the same thickness, while the thickness of the bent segment 2 is less than the thickness of the first solder segment 1 and the second solder segment 3. Furthermore, during manufacturing, the materials used for the first solder segment 1, the bent segment 2, and the second solder segment 3 are all of the same thickness.

[0027] Furthermore, as a preferred embodiment, the bent section 2 is provided with two stress relief grooves 23, which are arranged in parallel. The stress relief grooves 23 are used to disperse and release the stress on the bent section 2, allowing the entire bent section 2 to bear pressure more evenly and preventing defects such as cracks and deformation caused by excessive stress.

[0028] Furthermore, as a preferred embodiment, one end of the stress relief groove 23 extends to the first solder section 1, and the other end of the stress relief groove 23 extends to the second solder section 3.

[0029] Furthermore, in a preferred embodiment, a groove 31 is provided on the side of the second solder section 3 away from the bending section 2. Further, the groove 31 is used to assist in cutting the connecting ribs, making it easier to separate the copper clip body from the copper coil.

[0030] Furthermore, in a preferred embodiment, the thickness of the first solder segment 1 and the second solder segment 3 is 0.25 mm. Furthermore, due to the presence of the imprinting depth, the actual thickness of the bending segment 2 will be less than half the thickness of the first solder segment 1 and the second solder segment 3. Compared to the copper clip structure with a thickness of 0.203 mm in the prior art, when the thickness of the first solder segment 1 and the second solder segment 3 is set to 0.25 mm, the thickness of the bending segment 2 will also increase accordingly, thereby increasing the structural strength of the bending segment 2.

[0031] In another embodiment of this utility model, the thickness of the first solder section 1 and the second solder section 3 can also be set according to actual needs.

[0032] Furthermore, as a preferred embodiment, the first solder segment 1 includes a first horizontal segment, an inclined segment, and a second horizontal segment connected in sequence, one side of the bent segment 2 is connected to the second horizontal segment, and the lower end of the first horizontal segment is connected to the external lead frame through the first solder layer.

[0033] Furthermore, in a preferred embodiment, the second solder segment 3 includes a third horizontal segment, the other side of the bent segment 2 is connected to one side of the third horizontal segment, the lower end of the third horizontal segment can be connected to the external first chip through the second solder layer, and the upper end of the third horizontal segment can be connected to the external second chip through the third solder layer.

[0034] The working principle of this utility model is as follows: In use, the first horizontal segment of the first solder segment 1 can be connected to the source pin or gate pin of the lead frame through the first solder layer. Then, the lower end of the third horizontal segment of the second solder segment 3 can be connected to the first chip through the second solder layer. The upper end of the third horizontal segment of the second solder segment 3 can be connected to the second chip through the third solder layer. The first chip can be connected to the drain pin of the lead frame through the fourth solder layer. The second chip can be connected to another copper clip through the fifth solder layer. The other copper clip can be connected to the drain pin of the lead frame through the sixth solder layer.

[0035] The above description is only a preferred embodiment of the present utility model and does not limit the implementation method and protection scope of the present utility model. Those skilled in the art should realize that all solutions obtained by equivalent substitutions and obvious changes made based on the description and illustrations of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A copper clip structure suitable for large-size chip stacking packaging, characterized in that, include: The copper clip body includes a first solder section, a bending section and a second solder section connected in sequence. The bending section has a semi-etched groove, and the bottom walls on both sides of the semi-etched groove have a protrusion.

2. The copper clip structure for large-size chip stacking packaging according to claim 1, characterized in that, The end surface of the protrusion away from the sidewall of the semi-etched groove forms a clearance distance with the sidewall of the semi-etched groove.

3. The copper clip structure for large-size chip stacking packaging according to claim 1, characterized in that, An imprinting groove is formed on the bottom wall of the semi-etched tank at the position between the two protrusions.

4. The copper clip structure for large-size chip stacking packaging according to claim 1, characterized in that, The first solder segment and the second solder segment have the same thickness, and the thickness of the bent segment is less than the thickness of the first solder segment and the second solder segment.

5. The copper clip structure for large-size chip stacking packaging according to claim 1, characterized in that, Two stress relief grooves are provided on the bending section, and the two stress relief grooves are arranged in parallel.

6. The copper clip structure for large-size chip stacking packaging according to claim 5, characterized in that, One end of the stress relief groove extends to the first solder section, and the other end of the stress relief groove extends to the second solder section.

7. The copper clip structure for large-size chip stacking packaging according to claim 1, characterized in that, A groove is provided on the side of the second solder section away from the bent section.

8. The copper clip structure for large-size chip stacking packaging according to claim 1, characterized in that, The thickness of the first solder section and the second solder section is 0.25 mm.

9. The copper clip structure for large-size chip stacking packaging according to claim 1, characterized in that, The first solder section includes a first horizontal section, an inclined section, and a second horizontal section connected in sequence. One side of the bent section is connected to the second horizontal section, and the lower end of the first horizontal section is connected to the external lead frame through a first solder layer.

10. The copper clip structure for large-size chip stacking packaging according to claim 9, characterized in that, The second solder section includes a third horizontal section. The other side of the bent section is connected to one side of the third horizontal section. The lower end of the third horizontal section can be connected to the external first chip through the second solder layer, and the upper end of the third horizontal section can be connected to the external second chip through the third solder layer.

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