A lead frame structure and a semiconductor device

Abstract

This application provides a leadframe structure and a semiconductor device. The leadframe structure includes a base, a first flexible connection portion and a second flexible connection portion disposed on opposite sides of the base and extending upward from opposite sides of the base, a first pin connected to the end of the first flexible connection portion away from the base, and a second pin connected to the end of the second flexible connection portion away from the base. The first flexible connection portion and the second flexible connection portion are extendable and retractable along the height direction of the leadframe structure. The leadframe structure and semiconductor device provided in this application, with their first and second flexible connection portions extendable and retractable along the height direction of the leadframe, allow for flexible adjustment of the height of the first and second pins relative to the base, facilitating subsequent molding and effectively preventing molding compound overflow during molding, thereby improving the appearance and yield of the semiconductor device.

Description

Technical Field

[0001] This application relates to the field of semiconductor technology, and in particular to a lead frame structure and a semiconductor device. Background Technology

[0002] In the later stages of semiconductor device manufacturing, various components need to be packaged. After packaging, excess plastic material can easily accumulate on the surface of the semiconductor device, affecting its appearance and yield. Summary of the Invention

[0003] One aspect of this application provides a lead frame structure including a base, a first flexible connection portion and a second flexible connection portion disposed on opposite sides of the base and extending upward from the opposite sides, a first pin connected to the end of the first flexible connection portion away from the base and a second pin connected to the end of the second flexible connection portion away from the base, wherein the first flexible connection portion and the second flexible connection portion are extendable and retractable along the height direction of the lead frame structure.

[0004] Optionally, the material of the first flexible connection may include thermoplastic epoxy resin or a thermodegradable material.

[0005] Optionally, the material of the second flexible connection may include thermoplastic epoxy resin or a thermodegradable material.

[0006] Optionally, the height difference between the base and the first and second pins is 0.4mm-3mm.

[0007] Optionally, the thickness of the lead frame structure is 0.127 mm to 0.6 mm.

[0008] Optionally, along the height direction of the lead frame structure, the compressible height range of the first flexible connection and the second flexible connection is 0-0.6 mm.

[0009] Along the height direction of the lead frame structure, the first flexible connection and the second flexible connection can be stretched to a height range of 0-0.6 mm.

[0010] Optionally, the base may be made of copper.

[0011] Optionally, the first flexible connecting portion extends outward at an angle; the second flexible connecting portion extends outward at an angle.

[0012] Another aspect of this application provides a semiconductor device, including a chip and a lead frame structure as described above; wherein the chip is disposed on the base.

[0013] Optionally, the semiconductor device further includes an encapsulation structure that encapsulates the chip, with the base exposed on the side away from the chip.

[0014] The lead frame structure and semiconductor device provided in this application embodiment have a first flexible connection portion and a second flexible connection portion that are extendable and retractable along the height direction of the lead frame, so that the height of the first pin and the second pin of the lead frame structure relative to the base can be flexibly adjusted, which facilitates subsequent molding and can effectively avoid the overflow of molding compound during molding, thereby improving the appearance and yield of the semiconductor device. Attached Figure Description

[0015] Figure 1 The image shows a schematic diagram of the packaging of a semiconductor device in the related art;

[0016] Figure 2 The diagram shown is a packaging schematic of another semiconductor device in the related technology;

[0017] Figure 3 The diagram shown is a schematic representation of the lead frame structure of an exemplary embodiment of this application.

[0018] Figure 4 The diagram shown is a schematic representation of a lead frame structure of an exemplary embodiment of this application placed in a lower cavity pressing mold;

[0019] Figure 5 The diagram shown is a schematic representation of the fit between the lead frame structure and the lower cavity pressing mold in an exemplary embodiment of this application.

[0020] Figure 6 The diagram shown is a schematic representation of the packaging of a semiconductor device according to an exemplary embodiment of this application.

[0021] Figure 7 The diagram shown is another package schematic of a semiconductor device according to an exemplary embodiment of this application;

[0022] Figure 8 The diagram shown is a schematic diagram of the structure of a semiconductor device according to an exemplary embodiment of this application. Detailed Implementation

[0023] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0024] The terminology used in this application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. Unless otherwise defined, the technical or scientific terms used in this application should be understood in their ordinary sense by one of ordinary skill in the art to which this application pertains. The words “a” or “one” and similar terms used in this application specification and claims do not indicate a limitation of quantity, but rather indicate the presence of at least one. “A plurality” means two or more. The words “comprising” or “including” and similar terms mean that the element or object preceding “comprising” or “including” covers the element or object listed following “comprising” or “including” and its equivalents, and do not exclude other elements or objects. The words “connected” or “linked” and similar terms are not limited to physical or mechanical connections and can include electrical connections, whether direct or indirect. The words “above” and / or “below” and similar terms are for ease of description only and are not limited to a location or spatial orientation. The singular forms “a,” “the,” and “the” used in this application specification and appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any or all possible combinations of one or more associated listed items.

[0025] In the later stages of semiconductor device manufacturing, various components need to be packaged. In the packaged semiconductor device, surface overflow of the encapsulating material is prone to occur, affecting the appearance and yield of the semiconductor device. The inventors discovered through research that due to tolerances in the depth of the recessed base, when packaging structural components such as lead frames and chips with recessed bases, the depth of the lead frame structure and the molding die used for encapsulation cannot be well matched, resulting in encapsulation material overflow during encapsulation, thus affecting the product's appearance and yield. For details, please refer to... Figure 1 and Figure 2 As shown, Figure 1 The image shows a schematic diagram of the packaging of a semiconductor device in the related art. Figure 1 The process employs an upper cavity molding die 201' and a lower cavity molding die 202' to encapsulate the chip 300' and lead frame structure 100'. The base of the lead frame structure 100' is recessed deeper than the depth of the molding die 201', creating a gap 2001' between the leads on both sides of the lead frame structure 100' and the molding die 201'. This makes it easy for the encapsulating material to overflow from the gap 2001' during encapsulation. Furthermore, when using the lower cavity molding die 202' for pressing, the pressing stress can easily cause deformation of the lead frame structure 100', affecting product yield. Figure 2 The diagram shown is a packaging schematic of another semiconductor device in the related technology. Figure 2The chip 300” and lead frame structure 100” are encapsulated using an upper cavity molding die 201” and a lower cavity molding die 202”. The base of the lead frame structure 100” is recessed to a depth less than that of the molding die 201”, creating a gap 2001” between the base of the lead frame structure 100” and the molding die 201”. This results in a plastic-encapsulated structure on the outer side of the base of the lead frame structure 100” after encapsulation, which is detrimental to heat dissipation. If the plastic-encapsulated structure on the outer side of the base of the lead frame structure 100” is removed after encapsulation using methods such as grinding, it can easily lead to unevenness and height differences on the back surface of the semiconductor device, which can adversely affect the semiconductor device.

[0026] To solve the above-mentioned technical problems, this application provides a lead frame structure 100. Figure 3 The diagram shown is a schematic representation of the lead frame structure according to an exemplary embodiment of this application. Please refer to... Figure 3 As shown, the lead frame structure 100 includes a base 101, a first flexible connecting portion 102 and a second flexible connecting portion 103 disposed on opposite sides of the base 101 and extending upward from opposite sides of the base 101, and a first pin 104 connected to the end of the first flexible connecting portion 102 away from the base 101 and a second pin 105 connected to the end of the second flexible connecting portion 103 away from the base 101. The first flexible connecting portion 102 and the second flexible connecting portion 103 are extendable and retractable along the height direction of the lead frame structure 100.

[0027] It should be noted that the first flexible connection portion mentioned here can be understood as being partially or entirely formed of a flexible material. Similarly, the second flexible connection portion can also be understood as being partially or entirely formed of a flexible material.

[0028] In some embodiments, the material of the first flexible connection portion 102 includes thermoplastic epoxy resin or a thermodegradable material.

[0029] Accordingly, all or part of the first flexible connection is made of thermoplastic epoxy resin or a thermodegradable material, so that the first flexible connection is extensible, thereby realizing that the first flexible part is extensible in the height direction of the lead frame structure.

[0030] In one embodiment, the material of the second flexible connection 103 includes thermoplastic epoxy resin or a thermodegradable material.

[0031] Correspondingly, all or part of the second flexible connection is made of thermoplastic epoxy resin or a thermodegradable material, so that the second flexible connection is extensible, thereby realizing that the second flexible part is extensible in the height direction of the lead frame structure.

[0032] It should be noted that the flexible materials used in the first flexible connection and the second flexible connection can be the same or different.

[0033] Furthermore, in some embodiments, the height difference h between the base 101 and the second pin 105 is 0.4mm-3mm. The height difference between the base 101 and the first pin 104 is equal to the height difference h between the base 101 and the second pin 105, and its range is also 0.4mm-3mm. The height difference between the base 101 and the first pin 104 and the second pin 105 mentioned here can be understood as the sinking depth of the base 101.

[0034] In some embodiments, the thickness of the lead frame structure can be 0.127 mm to 0.6 mm.

[0035] Furthermore, in some embodiments, the compressible height range of the first flexible connection 102 and the second flexible connection 103 along the height direction of the lead frame structure is 0-0.6 mm.

[0036] Along the height direction of the lead frame structure, the first flexible connection 102 and the second flexible connection 103 can be stretched to a height range of 0-0.6mm.

[0037] In some embodiments, the base 101 is made of copper. The base 101 may be exposed in the semiconductor device for heat dissipation. The first and second pins are also made of copper.

[0038] In some embodiments, the first flexible connection portion 102 extends obliquely outward in the direction from the base 101 to the first pin 104. The second flexible connection portion 103 extends obliquely outward in the direction from the base 101 to the second pin 105. For example, in some embodiments, the first flexible connection portion 102 and the second flexible connection portion 103 may be symmetrically disposed on opposite sides of the base 101. Optionally, the first pin and the second pin may be symmetrically disposed on opposite sides of the base.

[0039] The lead frame structure and semiconductor device provided in this application embodiment have a first flexible connection portion and a second flexible connection portion that are extendable and retractable along the height direction of the lead frame, so that the height of the first pin and the second pin of the lead frame structure relative to the base can be flexibly adjusted. During subsequent molding, the lead frame structure and the molding die can fit tightly together, thereby effectively avoiding the overflow of molding compound during molding and improving the appearance and yield of the semiconductor device.

[0040] In addition, this application also provides a semiconductor device, such as Figure 8 As shown. Figure 8 The diagram shown is a schematic representation of a semiconductor device 1000 according to an exemplary embodiment of this application. Please refer to... Figure 8As shown, and combined where necessary. Figures 4 to 7 The semiconductor device 1000 includes a chip 300 and a lead frame structure 100 as described above. The chip 300 is disposed on the base 101.

[0041] Furthermore, in some embodiments, the semiconductor device 1000 also includes an encapsulation structure 400 that encapsulates a portion of the chip 300 and the lead frame structure 100. The base 101 is exposed on the side furthest from the chip to facilitate heat dissipation.

[0042] Furthermore, in some embodiments, the first pin 104 and the second pin 105 serve to support the base 101 during the packaging process and have no electrical lead-out function. The semiconductor device 1000 also adds pins with electrical lead-out function.

[0043] Please combine Figures 4 to 5 As shown, the base 101 of the lead frame structure 100 is recessed to a depth greater than that of the upper cavity molding die 201, creating a gap 2001 between the first pin 104 and the second pin 105 on both sides of the lead frame structure 100 and the upper cavity molding die 201. The first flexible connection portion 102 and the second flexible connection portion 103 of the lead frame structure 100 are extendable and retractable along the height direction of the lead frame structure 100. Under external force, the first flexible connection portion 102 and the second flexible connection portion 103 can be compressed, causing the first pin 104 and the second pin 105 of the lead frame structure 100 to descend and fit against the upper cavity molding die 201, thereby facilitating subsequent molding and preventing molding overflow.

[0044] Please combine Figure 6 and Figure 7 As shown, with the lower cavity pressing mold 202 cooperating with the upper cavity pressing mold 201, the lead frame structure 100 can fit well with both the upper cavity pressing mold 201 and the lower cavity pressing mold 202. Therefore, during molding, the pressing molds 201 and 202 and the lead frame structure 100 can be molded under sealed conditions to form a molded structure 400. After molding, the first lead 104 and the second lead 105 of the formed molded part are bent to form... Figure 8 The semiconductor device 1000 is shown. In this application, the device embodiments and method embodiments can complement each other without conflict.

[0045] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A lead frame structure, characterized by, The lead frame structure comprises a base (101), a first flexible connecting part (102) and a second flexible connecting part (103) arranged on opposite sides of the base (101) and extending upward from opposite sides of the base (101), and a first lead (104) connected to an end of the first flexible connecting part (102) away from the base (101) and a second lead (105) connected to an end of the second flexible connecting part (103) away from the base (101), the first flexible connecting part (102) and the second flexible connecting part (103) being stretchable and compressible along the height direction of the lead frame structure; the first flexible connecting part (102) is made of a thermal decomposition material, and the second flexible connecting part (103) is made of a thermal decomposition material. Along the height direction of the lead frame structure, the first flexible connecting part (102) and the second flexible connecting part (103) are compressible by 0-0.6 mm in height. Along the height direction of the lead frame structure, the first flexible connecting part (102) and the second flexible connecting part (103) are stretchable by 0-0.6 mm in height.

2. The leadframe structure of claim 1, wherein, The height difference between the base (101) and the first lead (104) and the second lead (105) is 0.4-3 mm.

3. The leadframe structure of claim 1, wherein, The thickness of the lead frame structure is 0.127-0.6 mm.

4. The leadframe structure of claim 1, wherein, The base (101) is made of copper.

5. The leadframe structure of claim 1, wherein, The first flexible connecting part (102) extends obliquely outward, and the second flexible connecting part (103) extends obliquely outward.

6. A semiconductor device, characterized by The semiconductor device further comprises a chip and the lead frame structure as claimed in any one of claims 1-5, wherein the chip is arranged on the base (101).

7. The semiconductor device of claim 6, wherein, The semiconductor device further comprises an encapsulation structure, the encapsulation structure encapsulating the chip, and the side of the base (101) away from the chip being exposed.

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