Lead frame plastic package body reinforcing structure and semiconductor product

Abstract

The application discloses a lead frame plastic package body reinforcing structure and a semiconductor product, which comprises a chip, a plurality of pins and metal leads, the metal leads have lead first ends welded with the chip and lead second ends welded with one of the pins; a plurality of fixing members are arranged on the pins, and the fixing members are arranged on the peripheral part of the lead second ends. Under the action of the fixing members, the plastic package body is difficult to be separated from the pins, so that the delamination phenomenon between the resin material of the plastic package body and the pins can be effectively avoided. Therefore, the semiconductor contact problem caused by the metal leads on the pins being pulled open due to the delamination between the resin material and the pins can be fundamentally solved.

Description

Technical Field

[0001] This application relates to the field of semiconductor technology, and more particularly to a leadframe encapsulation reinforcement structure and semiconductor product. Background Technology

[0002] As a chip carrier for integrated circuits, the lead frame is a key structural component that uses bonding materials (gold wire, aluminum wire, copper wire) to achieve electrical connection between the internal circuit leads of the chip and the external leads, forming an electrical circuit. It acts as a bridge connecting to external wires. Most semiconductor integrated circuits require the use of lead frames, which are an important basic material in the electronics and information industry.

[0003] The lead frame is usually made of copper or copper phosphate. Since copper is a metal that is very easy to oxidize, oxidation will greatly affect the soldering effect. Therefore, in order to prevent the lead frame from oxidizing, a layer of non-oxidizing material, such as nickel plating, is usually plated on the lead frame.

[0004] After soldering, the chip and lead frame need to be packaged. The current method is generally to use plastic encapsulation. The bonding between the resin material after plastic encapsulation and the lead frame pin surface is relatively weak, and delamination between the resin material and the pin is easy to occur. In the conventional lead frame structure, the pin soldering is single-point single-wire soldering, and the bonding strength between the solder joint and the pin is not high. Therefore, the delamination of the resin material can easily pull the solder joint on the pin apart, causing the chip and pin connection to fail. Summary of the Invention

[0005] The purpose of this invention is to provide a leadframe encapsulation reinforcement structure and semiconductor product that can solve the technical problem that existing leadframe pin bonding wires are easily pulled apart by the delaminated resin material.

[0006] To achieve the above objectives, this application adopts the following technical solution:

[0007] A lead frame encapsulation reinforcement structure includes a chip, multiple pins, and metal leads. The metal leads have a first end that is soldered to the chip and a second end that is soldered to one of the pins. Several fixing members are provided on the pins, and the fixing members are disposed around the second end of the lead.

[0008] Preferably, the fastener includes a plurality of first fixing posts distributed on the surface of the pin.

[0009] Preferably, the fastener further includes a second fixing post, which is located on top of the first fixing post, and at least one of the second fixing posts is simultaneously connected to two or more of the first fixing posts.

[0010] Preferably, the fixing component further includes a fixing lead wire, which is fixedly connected to the top surface of the first fixing post.

[0011] Preferably, the two ends of the fixed lead are respectively connected to two different first fixed posts.

[0012] Preferably, there are multiple fixed leads, and any two fixed leads are arranged to cross each other, are parallel to each other, or are at a certain angle to each other but do not cross each other.

[0013] Preferably, the fixing member includes a fixing lead wire, the two ends of which are fixedly connected to the pin, and the middle part of the fixing lead wire is bent and arched relative to the surface of the pin.

[0014] Preferably, the pin is made of a highly conductive material and has a protective layer on its surface. The protective layer is removed from a portion of the pin to form a welding area for welding the fastener.

[0015] Preferably, both the first fixing post and the second fixing post are weld points that are overlaid on the pipe feet.

[0016] A semiconductor product having the lead frame encapsulation reinforcement structure described above.

[0017] The beneficial effects of this application are as follows: This invention provides a leadframe molding compound reinforcement structure and a semiconductor product. A fixing member is provided on the pin surface. After the molding compound is injection molded, the resin coats the surface of the fixing member, and the fixing member is firmly bonded to the molding compound, making it difficult for the molding compound to separate from the fixing member. Because the fixing member is fixed to the pin, the molding compound is difficult to separate from the pin under the action of the fixing member, thereby effectively preventing delamination between the resin material of the molding compound and the pin. Therefore, this solution can fundamentally solve the problem of poor semiconductor contact caused by the delamination between the resin material and the pin, which pulls apart the metal leads on the pin. Attached Figure Description

[0018] The present application will now be described in further detail with reference to the accompanying drawings and embodiments.

[0019] Figure 1 This is a schematic diagram of the connection between a semiconductor chip and a lead frame in the prior art.

[0020] Figure 2 This is a schematic diagram of a lead frame encapsulation reinforcement structure according to an embodiment of the present invention;

[0021] Figure 3 for Figure 2 Schematic sectional view of section AA;

[0022] Figure 4 This is another structural schematic diagram of the lead frame encapsulation reinforcement structure described in the embodiments of the present invention;

[0023] Figure 5 for Figure 4 Schematic sectional view of section BB in the middle;

[0024] Figure 6 This is another structural schematic diagram of the lead frame encapsulation reinforcement structure described in the embodiment of the present invention;

[0025] Figure 7 for Figure 6 Schematic sectional view of the CC section;

[0026] Figure 8 This is a schematic diagram of another structure of the lead frame encapsulation reinforcement structure described in the embodiment of the present invention;

[0027] Figure 9 This is a schematic diagram of another structure of the lead frame encapsulation reinforcement structure described in the embodiment of the present invention;

[0028] Figure 10 for Figure 9 Schematic diagram of the cross-section DD.

[0029] Figure 11 This is another structural cross-sectional view of the lead frame encapsulation reinforcement structure pin portion described in an embodiment of the present invention.

[0030] In the picture:

[0031] 1. Chip; 2. Pin; 3. Metal lead; 4. Fixing component; 41. First fixing post; 42. Second fixing post; 43. Fixing lead. Detailed Implementation

[0032] To make the technical problems solved, the technical solutions adopted, and the technical effects achieved by this application clearer, the technical solutions of the embodiments of this application are further described in detail below. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0033] In the description of this application, unless otherwise expressly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0034] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0035] After the bonding connection between the internal chip and the pins in the lead frame is completed, the existing semiconductor needs to be encapsulated. Currently, resin materials are generally used for encapsulation, which forms a molded body on the semiconductor. However, since the bonding between the molded body and the lead frame pin surface is relatively weak after encapsulation, delamination problems can easily occur between the molded body and the pins.

[0036] To facilitate understanding of the prior art and the technical solution of this application, the connection structure between the lead frame 2 and the chip 1 in the prior art is described herein, with reference to... Figure 1 The present invention relates to a semiconductor interconnection structure, specifically a power semiconductor structure, comprising a chip 1 fixed on a lead frame, the lead frame having three pins: a first pin, a second pin, and a third pin, wherein the first pin is connected to the chip 1 by a metal lead 3, and the third pin is connected to the chip 1 by three metal leads 3. The metal leads 3 are fixed to the pins only by single-point soldering, therefore the bonding strength between the solder joint and the pin is not strong.

[0037] When delamination occurs between the molding compound and the pin surface, the molding compound can easily pull apart the metal lead 3, which has insufficient stability, causing the chip 1 to fail to connect with the pin, thus leading to the semiconductor being scrapped.

[0038] To address the aforementioned problems, this application employs a series of reinforcement measures for the lead frame encapsulation. The methods used in this application to solve these problems are described in detail below:

[0039] Example 1.

[0040] Reference Figure 2 A lead frame encapsulation reinforcement structure includes a chip 1, multiple pins 2 and metal leads 3. The metal leads 3 have a first end that is soldered to the chip 1 and a second end that is soldered to one of the pins 2. The pins 2 are provided with a plurality of fixing members 4, which are disposed around the periphery of the second end of the lead.

[0041] Reference Figure 2 This embodiment is a power semiconductor. Chip 1 is fixed on a lead frame, which includes three pins 2: a first pin, a second pin, and a third pin. The first pin is connected to chip 1 by a metal lead 3, and the third pin is connected to chip 1 by three metal leads 3. The third pin has three metal leads 3, which provide a high bonding strength between the metal leads 3 and the pin, further strengthening the bond between the encapsulation and the third pin. Therefore, no reinforcement structure is needed. Of course, those skilled in the art can also provide a fixing member for reinforcement on the third pin according to actual needs. The first pin only has one metal lead 3, resulting in a weaker bonding strength between the metal lead 3 and the pin 2, and the encapsulation is easily separated from the pin. Therefore, in this embodiment, a fixing member for reinforcing the encapsulation is provided on the first pin to prevent the resin from separating from the pin.

[0042] In this embodiment, the fastener 4 is located around the second end of the lead wire, meaning that the fastener 4 is located near the second end of the lead wire but does not contact the lead wire. This increases the number of fastening structures protruding from the surface of the pin 2, thereby increasing the contact area between the pin 2 and the resin and thus increasing the bonding force.

[0043] It should be noted that the reinforcement method of the molding compound in this application is not only applicable to the power semiconductor in this embodiment, but also applicable to the reinforcement of molding compounds of other semiconductors. The scope of protection of this application should not be construed as limited to the application of power semiconductors. In other semiconductors, any application that does not depart from the inventive spirit of this application should be understood as being covered by the scope of protection of this application.

[0044] In this embodiment, a retainer 4 is provided on the surface of pin 2. After the molding of the encapsulation is completed, the resin coats the surface of the retainer 4, and the retainer 4 is firmly bonded to the encapsulation, making it difficult for the encapsulation to separate from the retainer 4. Because the retainer 4 is fixed to pin 2, the encapsulation is difficult to separate from pin 2 under the action of the retainer 4, thereby effectively preventing delamination between the resin material of the encapsulation and pin 2. Therefore, this solution can fundamentally solve the problem of poor semiconductor contact caused by the delamination between the resin material and pin 2, which pulls apart the metal leads on the pin.

[0045] As a preferred configuration in this embodiment, refer to... Figure 2-3 The fastener 4 includes a plurality of first fixing posts 41 distributed on the surface of the pin 2. During molding, the resin material bonds with the surface of each first fixing post 41. The first fixing posts 41 strengthen the bond with the resin material, thereby preventing the resin material from delaminating from the surface of the pin 2.

[0046] Furthermore, refer to Figure 4-5 The fixing member 4 further includes a second fixing post 42, which is located on top of the first fixing post 41. At least one second fixing post 42 is simultaneously connected to two or more first fixing posts 41. In this structure, a certain hole is formed between the first fixing post 41 and the second fixing post 42. During the molding process, the resin fills the hole, and the resin and the fixing member 4 form a mutually encapsulating and locking structure, thereby ensuring a firm bond between the resin and the fixing member 4 and effectively preventing delamination of the molding compound.

[0047] As another preferred configuration in this embodiment, refer to... Figure 6-8 The fixing member 4 also includes a fixing lead wire 43, which is fixedly connected to the top surface of the first fixing post 41.

[0048] Furthermore, both ends of the fixing lead 4 are connected to two different first fixing posts 41. Similar to the structure of the first fixing post 41 and the second fixing post 42, the fixing lead 43 is laid horizontally on the two first fixing posts 41, forming a hole similar to a bridge between the fixing lead 43 and the first fixing post 41. During the molding process, the resin fills the hole, and the resin and the fixing member 4 form a mutually wrapped and locked structure, thereby ensuring a firm bond between the resin and the fixing member 4 and effectively preventing delamination of the molding compound.

[0049] Specifically, there are multiple fixed leads 43, and any two fixed leads 43 are arranged to cross each other, be parallel to each other, or be at a certain angle to each other but not cross each other. Fixed leads 43 in various configurations can be combined with each other, such as... Figure 6 and Figure 8 Two preferred bonding methods are shown, and those skilled in the art can make adaptive changes to the bonding morphology according to actual needs.

[0050] As another preferred configuration in this embodiment, refer to... Figure 9-10The fixing component 4 is a fixing lead 43, with both ends of the fixing lead 43 fixedly connected to the pin 2, and the middle part of the fixing lead 43 is curved and arched relative to the surface of the pin 2. Thus, a hole similar to a bridge is formed between the fixing lead 43 and the pin 2. During molding and injection, the resin fills the hole, and a mutually encapsulating and locking structure is formed between the resin and the fixing lead 43, thereby ensuring a firm bond between the resin and the fixing component and effectively preventing delamination of the molding compound.

[0051] It should be noted that the fasteners described in this solution are not limited to the above-mentioned technical solutions that only have a first fixing post 41, have both a first fixing post 41 and a second fixing post 42, have a first fixing post 41 and a fixing lead wire 43, or only have a fixing lead wire 43. Figure 11 As shown, in other embodiments, the fixing member 4 may include a first fixing post 41, a second fixing post 42, and a fixing lead wire 43. There are multiple first fixing posts 41, which are distributed on the surface of the pin 2. The second fixing post 42 is located on top of the first fixing post 41. At least one second fixing post 42 is connected to two or more first fixing posts 41 at the same time. The two ends of the fixing lead wire 43 are respectively connected to the top surfaces of two second fixing posts 42.

[0052] With this configuration, while a hole is formed between the first fixing post 41 and the second fixing post 42, a larger space is also formed between the fixing lead 43 and the pin 2. This space can accommodate more resin, thereby increasing the connection strength between the resin and the pin 2.

[0053] Furthermore, in this solution, the pin 2 is made of a highly conductive material and has a protective layer on its surface. By removing the protective layer from a portion of the pin 2, a welding area for welding the fastener is formed.

[0054] Specifically, in this embodiment, the pin 2 is made of copper, and the protective layer is a nickel plating layer. The nickel material on the welding area is removed to expose the copper material, forming the welding area. All solder joints on the pin 2 are located on the welding area. Since the pin 2 is generally made of copper, its surface is prone to oxidation. Nickel plating on the surface of the pin 2 can protect its surface. However, due to the presence of the nickel plating layer, it is difficult to form a metal compound between the fastener 4 and the nickel layer surface, making the welding unreliable. Therefore, in this solution, the nickel material is ground away in the welding area to expose the copper material. During welding, the solder can fuse with the copper to form a metal compound, thereby ensuring a firm and reliable connection between the fastener 4 and the pin 2.

[0055] Preferably, the first fixing post 41 and the second fixing post 42 are both weld points that are overlaid on the pin 2. The first fixing post 41 and the second fixing post 42 formed by directly overlaying on the pin 2 have the advantages of good bonding with the pin 2 and high bonding strength.

[0056] Example 2.

[0057] This embodiment discloses a semiconductor product having the lead frame encapsulation reinforcement structure described in Embodiment 1.

[0058] In the description herein, it should be understood that the terms "upper," "lower," "left," "right," and other orientations or positional relationships are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Furthermore, the terms "first" and "second" are used merely for descriptive distinction and have no special meaning.

[0059] In the description of this specification, references to terms such as "an embodiment," "example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example.

[0060] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style of the specification is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

[0061] The technical principles of this application have been described above with reference to specific embodiments. These descriptions are merely for explaining the principles of this application and should not be construed as limiting the scope of protection of this application in any way. Based on this explanation, those skilled in the art can readily conceive of other specific embodiments of this application without inventive effort, and these embodiments will all fall within the scope of protection of this application.

Claims

1. A reinforcing structure for a lead frame encapsulation, characterized in that, The device includes a chip (1), multiple pins (2), and metal leads (3). The metal leads (3) have a first end that is soldered to the chip (1) and a second end that is soldered to one of the pins (2). A plurality of fasteners (4) are provided on the pins (2). The fasteners (4) are located around the second end of the lead. The fasteners (4) are located around the second end of the lead and are configured such that they are near the second end of the lead but do not contact the second end of the lead. The fastener (4) includes a plurality of first fixing posts (41) distributed on the surface of the pin (2); The fastener (4) further includes a second fixing post (42), which is located on top of the first fixing post (41), and at least one second fixing post (42) is connected to two or more first fixing posts (41) at the same time. Among them, a certain hole is formed between the first fixing post (41) and the second fixing post (42). During the molding and injection, the resin fills the hole, and the resin and the fixing member (4) form a structure that wraps and locks each other.

2. The lead frame encapsulation reinforcement structure according to claim 1, characterized in that, The fixing member (4) also includes a fixing lead (43), which is fixedly connected to the top surface of the first fixing post (41).

3. The lead frame encapsulation reinforcement structure according to claim 2, characterized in that, The two ends of the fixed lead (43) are respectively connected to two different first fixed posts (41).

4. The lead frame encapsulation reinforcement structure according to claim 3, characterized in that, There are multiple fixed leads (43), and any two fixed leads (43) are arranged to cross each other, parallel to each other, or at a certain angle but not crossing each other.

5. The lead frame encapsulation reinforcement structure according to claim 1, characterized in that, The fastener (4) includes a fixing lead (43), both ends of which are fixedly connected to the pin (2), and the middle part of the fixing lead (43) is bent and arched relative to the surface of the pin (2).

6. A lead frame encapsulation reinforcement structure according to any one of claims 1-5, characterized in that, The pin (2) is made of a highly conductive material and has a protective layer on its surface. The protective layer is removed from a portion of the pin (2) to form a welding area for welding the fastener.

7. The lead frame encapsulation reinforcement structure according to claim 1, characterized in that, The first fixing post (41) and the second fixing post (42) are both weld points that are overlaid on the pipe foot (2).

8. A semiconductor product, characterized in that, It has a lead frame encapsulation reinforcement structure as described in any one of claims 1-7.

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