A lead frame package structure with electromagnetic shielding

Abstract

This application provides a leadframe package structure with electromagnetic shielding, including a leadframe with a base island, ground pins, and non-ground pins; a chip structure disposed on the upper surface of the base island; a molding compound layer on the surface of the leadframe, wherein a first stepped groove is formed on the sidewall of the molding compound away from the upper surface of the leadframe; a ground connection layer located on the bottom wall of the first stepped groove; an electromagnetic shielding layer located on the surface of the molding compound; an electromagnetic shielding connector and a ground wire located within the molding compound, wherein both ends of the electromagnetic shielding connector are electrically connected to the ground connection layer and the electromagnetic shielding layer, respectively; and both ends of the ground wire are electrically connected to the ground connection layer and the ground pin, respectively, so that the electromagnetic shielding layer and the electromagnetic shielding connector are grounded. This structural design allows the leadframe package structure to form an electromagnetic shielding structure by setting a ground connection layer, an electromagnetic shielding layer, and an electromagnetic shielding connector, without requiring a complex wire bonding process.

Description

Technical Field

[0001] This application relates to the field of semiconductor packaging, and more particularly to a lead frame packaging structure with electromagnetic shielding. Background Technology

[0002] Electromagnetic shielding structures in semiconductor devices are primarily used to prevent electromagnetic interference (EMI) and electromagnetic leakage (EMC). Semiconductor devices generate electromagnetic waves during operation, which can interfere with surrounding electronic equipment. Electromagnetic shielding structures can block these electromagnetic waves from propagating outward, reducing interference to other devices. For example, on a computer motherboard, various semiconductor chips and electronic components are densely distributed. Without electromagnetic shielding measures, interference between chips can lead to signal transmission errors, logic gate malfunctions, and other problems. Electromagnetic shielding structures can effectively suppress electromagnetic waves generated by these internal interference sources, ensuring the normal operation of the entire electronic system. Simultaneously, external electromagnetic waves can also interfere with the normal operation of semiconductor devices. Electromagnetic shielding structures can provide a relatively stable electromagnetic environment for semiconductor devices, preventing external electromagnetic attacks, such as electromagnetic pulses (EMPs), from damaging the internal structure of the device. When electromagnetic waves encounter a shielding layer, they are attenuated through reflection, absorption, and scattering. Electromagnetic shielding structures can reflect, absorb, and scatter external electromagnetic waves, preventing them from entering the semiconductor device and thus protecting it from external electromagnetic interference. Electromagnetic shielding structures are typically made of highly conductive materials, such as metals like copper, aluminum, and silver, or conductive polymer composites.

[0003] Existing electromagnetic shielding technology using electromagnetic shielding wires can only be used in substrate-based packages. Because the substrate contains internal wiring, the bonding wires spanning the chip surface can be connected to a single ground signal through these internal circuitry, thus achieving electromagnetic shielding. However, for leadframe-based packages, the leadframe only has pins. These pins are used to transmit various signals between the chip and external circuits, and each pin transmits a different electrical signal. Since the electromagnetic shielding wire only transmits a single ground signal, it is impossible to achieve electromagnetic shielding by creating a cross-chip electromagnetic shielding line by bonding wires to the pins. Summary of the Invention

[0004] The problem this application aims to solve is to provide a lead frame packaging structure with electromagnetic shielding, which enables the formation of an electromagnetic shielding structure with excellent electromagnetic shielding effect on the lead frame packaging structure.

[0005] To address the aforementioned problems, this application provides a lead frame packaging structure with electromagnetic shielding, comprising:

[0006] A lead frame, the lead frame including a base island and pins disposed outside the base island, the pins including grounded pins and non-grounded pins;

[0007] A chip structure, wherein the chip structure is disposed on the upper surface of the base island;

[0008] A molding layer is located on the surface of the lead frame and covers the chip structure, and exposes the lower surface of the lead frame. The molding layer has a first stepped groove on its sidewall near the upper surface of the lead frame.

[0009] A grounding connection layer is located on the bottom wall of the first step groove, and the grounding connection layer is not in direct contact with the pin.

[0010] An electromagnetic shielding layer, wherein the electromagnetic shielding layer is located on the surface of the encapsulation layer away from the lead frame;

[0011] An electromagnetic shielding connector is located within the plastic encapsulation layer. One end of the electromagnetic shielding connector is electrically connected to the upper surface of the grounding connection layer, and the other end is electrically connected to the lower surface of the electromagnetic shielding layer.

[0012] A grounding wire is located within the plastic encapsulation layer. The two ends of the grounding wire are electrically connected to the upper surface of the grounding connection layer and the upper surface of the grounding pin of the lead frame, respectively, so as to ground the electromagnetic shielding layer and the electromagnetic shielding connector.

[0013] In an optional embodiment, the electromagnetic shielding connector is a connecting post or a vertically arranged wire perpendicular to the grounding connection layer.

[0014] In an optional embodiment, the electromagnetic shielding connectors include a plurality of connectors arranged circumferentially around the chip structure.

[0015] In an optional embodiment, the lead frame has a plurality of pins, and a plurality of electromagnetic shielding connectors are provided corresponding to the plurality of pins.

[0016] In an optional embodiment, a protective layer is further included, which is located on the surface of the electromagnetic shielding layer.

[0017] In an optional embodiment, the molding layer has a second stepped groove on the surface near the lead frame, and the first stepped groove is located at the bottom of the second stepped groove, thereby preventing the grounding connection layer from directly contacting the pin.

[0018] In an optional embodiment, the first step groove and the second step groove are respectively annular step grooves arranged in a circumferential direction around the chip structure.

[0019] In an optional embodiment, the horizontal plane containing the bottom surface of the second stepped groove is at least lower than the horizontal plane containing the upper surface of the chip structure on the side away from the lead frame.

[0020] In an optional embodiment, the bottom surface of the second stepped groove is at a level higher than or level with the upper surface of the lead frame pins on the side closest to the chip structure.

[0021] In an optional embodiment, the grounding connection layer is a continuous annular connection ring arranged circumferentially around the chip structure.

[0022] In an optional embodiment, the first stepped groove includes a plurality of first stepped grooves arranged circumferentially around the chip structure;

[0023] The grounding connection layer has multiple blocks, and each block of the grounding connection layer is correspondingly arranged with multiple first step grooves.

[0024] In an optional embodiment, the lead frame has at least one ground pin;

[0025] The grounding connection layer has at least one piece, and at least one grounding connection layer is provided corresponding to the grounding pin.

[0026] In an optional embodiment, the grounding connection layer is located on the bottom surface of the first stepped groove and at least a portion of the side surface of the first stepped groove.

[0027] In an optional embodiment, the height of the grounding connection layer is less than or equal to the side height of the first step groove.

[0028] In an optional embodiment, it further includes bonding wires located within the molding compound;

[0029] The two ends of the bonding wire are electrically connected to the pads on the upper surface of the chip structure and the pins of the lead frame, respectively.

[0030] In an optional embodiment, the chip structure is flip-chip disposed on the upper surface of the pins.

[0031] The advantages of the technical solution in this application are:

[0032] By forming a first stepped groove on the molding compound, a ground connection layer is formed on the surface of the first stepped groove. An electromagnetic shielding connector is then vertically disposed on the ground connection layer and electrically connected to it. An electromagnetic shielding layer is then disposed at the end of the electromagnetic shielding connector furthest from the ground connection layer, thus forming an electromagnetic shielding structure on the outside of the chip structure, consisting of the ground connection layer, the electromagnetic shielding layer, and the electromagnetic shielding connector. Simultaneously, a ground wire connects the ground connection layer and the ground pin of the leadframe, ensuring that the entire electromagnetic shielding structure is grounded. This structural design allows the leadframe packaging structure to form an electromagnetic shielding structure by incorporating a ground connection layer, an electromagnetic shielding layer, and an electromagnetic shielding connector, without requiring complex wire bonding.

[0033] Furthermore, multiple electromagnetic shielding connectors are arranged circumferentially around the chip structure. Combined with the electromagnetic shielding layer on top of the chip structure, electromagnetic shielding can be achieved on all five sides of the chip structure, thereby giving the packaging structure a better electromagnetic shielding effect.

[0034] Furthermore, the electromagnetic shielding layer is protected by a protective layer, and the grounding connection layer and the outer side of the electromagnetic shielding connector are covered with a plastic sealant, which makes the electromagnetic shielding structure wear-resistant and enhances the stability of the electromagnetic shielding.

[0035] Furthermore, the second step groove can block the connection between the grounding connection layer and the non-grounded pins of the lead frame, except for the grounding pins. Attached Figure Description

[0036] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort. In addition, in the following drawings, the components are not necessarily drawn to scale, and components with similar related characteristics or features may have the same or similar reference numerals.

[0037] Figure 1 This is a schematic diagram of the lead frame packaging structure with electromagnetic shielding according to an embodiment of this application, viewed from the front.

[0038] Figure 2 This is a schematic diagram of the lead frame encapsulation structure with electromagnetic shielding according to an embodiment of this application along A1-A2;

[0039] Figure 3 This is a schematic diagram of a method for forming a lead frame packaging structure with electromagnetic shielding in one embodiment of this application. Figure 1 ;

[0040] Figure 4 This is a schematic diagram of a method for forming a lead frame packaging structure with electromagnetic shielding in one embodiment of this application. Figure 2 ;

[0041] Figure 5 for Figure 4 Corresponding top view structural diagram (and Figure 4 for Figure 5 (Cross-section view along B1-B2)

[0042] Figure 6 This is a schematic diagram of a method for forming a lead frame packaging structure with electromagnetic shielding in one embodiment of this application. Figure 3 ;

[0043] Figure 7 for Figure 6 The corresponding top-view structural diagram (except for the electromagnetic shielding wire and the grounding wire, the rest of the structure is blurred, and...) Figure 6 for Figure 7 (Cross-section view along C1-C2)

[0044] Figure 8 This is a schematic diagram of a method for forming a lead frame packaging structure with electromagnetic shielding in one embodiment of this application. Figure 4 ;

[0045] Figure 9 This is a schematic diagram of a method for forming a lead frame packaging structure with electromagnetic shielding in one embodiment of this application. Figure 5 ;

[0046] Figure 10 This is a schematic diagram of a method for forming a lead frame packaging structure with electromagnetic shielding in one embodiment of this application. Figure 6 ;

[0047] Figure 11 This is a schematic diagram of a method for forming a lead frame packaging structure with electromagnetic shielding in one embodiment of this application. Figure 7 ;

[0048] Figure 12 This is a schematic diagram of a method for forming a lead frame packaging structure with electromagnetic shielding in one embodiment of this application. Figure 8 ;

[0049] Figure 13 This is a schematic diagram of a method for forming a lead frame packaging structure with electromagnetic shielding in one embodiment of this application. Figure 9 ;

[0050] Figure 14 This is a top view of a lead frame encapsulation structure with electromagnetic shielding according to another embodiment of this application.

[0051] Figure 15 This is a schematic diagram of the lead frame encapsulation structure with electromagnetic shielding according to another embodiment of this application, viewed from the front.

[0052] Figure 16 This is a schematic diagram of the lead frame encapsulation structure with electromagnetic shielding according to another embodiment of this application, viewed from the front.

[0053] Figure 17 This is a schematic diagram of the lead frame encapsulation structure with electromagnetic shielding according to another embodiment of this application, viewed from the front.

[0054] Figure 18 This is a schematic diagram illustrating the process of forming a lead frame packaging structure with electromagnetic shielding in one embodiment of this application.

[0055] The labels for the attached figures are as follows:

[0056] 1. Lead frame; 11. Base island; 12. Grounding pin; 13. Non-grounding pin; 14. Connecting rib; 2. Chip structure; 3. Molding layer; 31. First step groove; 32. Second step groove; 33. First groove; 34. Second groove; 4. Grounding connection layer; 5. Electromagnetic shielding connector; 6. Grounding wire; 7. Adhesive layer; 8. Bonding wire; 9. Electromagnetic shielding layer; 10. Protective layer; 100. Frame unit. Detailed Implementation

[0057] To make the technical problems, technical solutions and beneficial effects to be solved by this application clearer, the following describes this application in further detail with reference to the accompanying drawings and embodiments.

[0058] In the description of this application, it should be noted that the use of terms such as "first" and "second" to define objects (such as elements, components, regions, layers, doping types and / or parts) is merely for the purpose of distinguishing different objects and is not necessarily used to describe a specific order or sequence. Unless the context clearly indicates otherwise, it should be understood that such data can be used interchangeably where appropriate.

[0059] In the description of this application, it should be understood that the singular forms “a,” “an,” and “the” may also include the plural forms unless the context clearly indicates otherwise. It should also be understood that when the terms “compose” and / or “comprise” are used in this specification, the presence of the stated feature, integer, step, operation, element, and / or part is established, but the presence or addition of one or more other features, integers, steps, operations, elements, parts, and / or groups is not excluded. Meanwhile, when used herein, the term “and / or” includes any and all combinations of the associated listed items.

[0060] In the description of this application, it should also be noted that when a component is referred to as "on another component," "connected to another component," or "in contact with another component," it can mean not only that a component is directly on, directly connected to, or directly in contact with the other component, but also that an intermediate component can be inserted between the two components. Furthermore, "connection" includes not only fixed connections but also detachable connections or integral connections. Similarly, when an element is referred to as "electrically connected," "electrically contacted," "electrically coupled," or "electrically coupled to" another element, the two elements can be in direct electrical contact or electrical coupling, or they can be in electrical contact or electrical coupling through an intermediate component.

[0061] In the description of this application, it should also be noted that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is usually based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this application and simplifying the description. Unless otherwise stated, these directional terms 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 on the scope of protection of this application; the directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0062] Furthermore, in the description of this application, spatial relation terms such as "below," "under," "below," "below," "below," "above," "on the upper surface of," "above," etc., can be used to describe the spatial positional relationship between one element or feature shown in the figures and other elements or features. It should be understood that spatial relation terms, in addition to the orientation shown in the figures, also include different orientations of elements or features in use and operation. For example, if an element or feature in the figures is flipped or inverted, an element or feature described as "below" or "below" other elements or features will be oriented "above" other elements or features. Furthermore, elements may also include other orientations (e.g., rotated by an angle or other orientations).

[0063] This application provides a lead frame packaging structure with electromagnetic shielding, in conjunction with reference to [reference needed]. Figures 1-18 ,in Figure 1 for Figure 1 This is a schematic diagram of the lead frame packaging structure with electromagnetic shielding according to an embodiment of this application, viewed from the front. Figure 2 This is a schematic diagram of the lead frame encapsulation structure with electromagnetic shielding according to an embodiment of this application along A1-A2; Figure 3 This is a schematic diagram of a method for forming a lead frame packaging structure with electromagnetic shielding in one embodiment of this application. Figure 1 ; Figure 4 This is a schematic diagram of a method for forming a lead frame packaging structure with electromagnetic shielding in one embodiment of this application. Figure 2 ; Figure 5 for Figure 4 Corresponding top view structural diagram (and Figure 4 for Figure 5 (Cross-section view along B1-B2) Figure 6 This is a schematic diagram of a method for forming a lead frame packaging structure with electromagnetic shielding in one embodiment of this application. Figure 3 ; Figure 7 for Figure 6 The corresponding top-view structural diagram (except for the electromagnetic shielding wire and the grounding wire, the rest of the structure is blurred, and...) Figure 6 for Figure 7 (Cross-section view along C1-C2) Figure 8 This is a schematic diagram of a method for forming a lead frame packaging structure with electromagnetic shielding in one embodiment of this application. Figure 4 ; Figure 9 This is a schematic diagram of a method for forming a lead frame packaging structure with electromagnetic shielding in one embodiment of this application. Figure 5 ; Figure 10 This is a schematic diagram of a method for forming a lead frame packaging structure with electromagnetic shielding in one embodiment of this application. Figure 6 ; Figure 11 This is a schematic diagram of a method for forming a lead frame packaging structure with electromagnetic shielding in one embodiment of this application. Figure 7 ; Figure 12 This is a schematic diagram of a method for forming a lead frame packaging structure with electromagnetic shielding in one embodiment of this application. Figure 8 ; Figure 13 This is a schematic diagram of a method for forming a lead frame packaging structure with electromagnetic shielding in one embodiment of this application. Figure 9 ; Figure 14 This is a top view of a lead frame encapsulation structure with electromagnetic shielding according to another embodiment of this application. Figure 15 This is a schematic diagram of the lead frame encapsulation structure with electromagnetic shielding according to another embodiment of this application, viewed from the front. Figure 16 This is a schematic diagram of the lead frame encapsulation structure with electromagnetic shielding according to another embodiment of this application, viewed from the front. Figure 17 This is a schematic diagram of the lead frame encapsulation structure with electromagnetic shielding according to another embodiment of this application, viewed from the front. Figure 18 This is a schematic flowchart illustrating the formation of an electromagnetically shielded lead frame package structure in one embodiment of this application; the electromagnetically shielded lead frame package structure includes:

[0064] The lead frame 1 includes a base island 11 and pins disposed outside the base island 11, including a grounded pin 12 and a non-grounded pin 13.

[0065] Chip structure 2, chip structure 2 is disposed on the surface of base island 11;

[0066] A molding layer 3 is located on the surface of the lead frame 1 and covers the chip structure 2, and exposes the lower surface of the lead frame. A first stepped groove 31 is formed on the sidewall of the molding layer 3 near the upper surface of the lead frame 1.

[0067] Grounding connection layer 4 is located on the bottom wall of the first step groove 31, and the grounding connection layer 4 is not in direct contact with the pin;

[0068] Electromagnetic shielding layer 9 is located on the surface of the molding layer 3 away from the lead frame 1;

[0069] Electromagnetic shielding connector 5 is located inside the plastic encapsulation layer 3. One end of the electromagnetic shielding connector 5 is electrically connected to the upper surface of the grounding connection layer 4, and the other end is electrically connected to the lower surface of the electromagnetic shielding layer 9.

[0070] Grounding wire 6 is located inside the plastic encapsulation layer 3. The two ends of grounding wire 6 are electrically connected to the upper surface of the grounding connection layer 4 and the upper surface of the grounding pin 12 of the lead frame 1, respectively, so as to ground the electromagnetic shielding layer 9 and the electromagnetic shielding connector 5.

[0071] Existing electromagnetic shielding technology using electromagnetic shielding wires can only be used in substrate-based packages. Because the substrate contains internal wiring, the bonding wires spanning the chip surface can be connected to a single ground signal through these internal circuitry, thus achieving electromagnetic shielding. However, for leadframe-based packages, the leadframe only has pins. These pins are used to transmit various signals between the chip and external circuits, and each pin transmits a different electrical signal. Since the electromagnetic shielding wire only transmits a single ground signal, it is impossible to achieve electromagnetic shielding by creating a cross-chip electromagnetic shielding line by bonding wires to the pins.

[0072] This application forms a first stepped groove 31 on the molding compound 3, a ground connection layer 4 on the surface of the first stepped groove 31, and an electromagnetic shielding connector 5 vertically disposed on the upper surface of the ground connection layer 4 and electrically connected to the ground connection layer 4. An electromagnetic shielding layer 9 is then disposed at the end of the electromagnetic shielding connector 5 away from the ground connection layer 4, thus forming an electromagnetic shielding structure on the outside of the chip structure 2, consisting of the ground connection layer 4, the electromagnetic shielding layer 9, and the electromagnetic shielding connector 5. Simultaneously, a grounding wire 6 connects the ground connection layer 4 and the grounding pin 12 of the lead frame 1, ensuring that the entire electromagnetic shielding structure is grounded. In other words, this structural design allows the lead frame 1's encapsulation structure to form an electromagnetic shielding structure by simply setting the ground connection layer 4, the electromagnetic shielding layer 9, and the electromagnetic shielding connector 5, without requiring a complex wire bonding process.

[0073] In one embodiment, the electromagnetic shielding connector 5 consists of multiple connecting pillars vertically arranged relative to the grounding connection layer 4, with the multiple connecting pillars arranged circumferentially around the chip structure 2.

[0074] In one embodiment, the lead frame 1 has a plurality of pins, and a plurality of connecting posts are provided corresponding to the plurality of pins.

[0075] Please refer to Figure 14 In another embodiment, multiple connecting posts and multiple pins may not be arranged in a corresponding manner, and connecting posts may also be provided in the grounding connection layer 4 at the corresponding pinless positions.

[0076] In another embodiment, the electromagnetic shielding connector 5 consists of multiple vertical solder wires, in which case the multiple vertical solder wires are arranged corresponding to multiple pins.

[0077] In another embodiment, multiple vertical solder lines can be provided in a non-corresponding manner to multiple pins, and multiple vertical solder lines can also be provided in the grounding connection layer 4 at the corresponding pinless position.

[0078] Please refer to Figure 16 In one embodiment, a protective layer 10 is also included, which is located on the upper surface of the electromagnetic shielding layer 9.

[0079] Existing technologies use metal sputtering on the outside of the encapsulated body to form electromagnetic shielding. However, since the shielding layer is directly exposed to the outside, it is easily damaged by external forces or environmental factors during use, which reduces or eliminates the shielding effect.

[0080] The encapsulation structure provided in this application protects the electromagnetic shielding layer 9 with a protective layer 10, and the electromagnetic shielding connector 5 is covered with a plastic encapsulation layer 3, which makes the electromagnetic shielding structure wear-resistant and enhances the stability of the electromagnetic shielding.

[0081] Please refer to Figure 17 In another embodiment, the electromagnetic shielding layer 9 is disposed on a portion of the surface of the encapsulation layer 3, and the protective layer 10 is located on the upper surface and side surface of the electromagnetic shielding layer 9. The protective layer 10 located on the side surface of the electromagnetic shielding layer 9 is connected to the exposed encapsulation layer 3 of the electromagnetic shielding layer 9.

[0082] This arrangement enhances the bonding between the molding layer 3 and the electromagnetic shielding layer 9, preventing the electromagnetic shielding layer 9 from delaminating relative to the molding layer 3.

[0083] In one embodiment, the protective layer 10 is a protective layer 10 formed of molding compound.

[0084] In one embodiment, the molding layer 3 has a second stepped groove 32 on the surface near the lead frame 1, and the first stepped groove 31 is located at the bottom of the second stepped groove 32. The second stepped groove 32 is used to prevent the grounding connection layer 4 from directly contacting the pin.

[0085] In one embodiment, the first step groove 31 and the second step groove 32 are respectively annular step grooves arranged in a circumferential direction around the chip structure 2.

[0086] In one embodiment, the horizontal plane of the bottom surface of the second step groove 32 is at least lower than the horizontal plane of the upper surface of the chip structure 2 on the side away from the lead frame 1.

[0087] In one embodiment, the bottom surface of the second step groove 32 is at a level higher than or level with the upper surface of the lead frame 1 on the side of the lead frame 1 closest to the chip structure 2.

[0088] In one embodiment, the grounding connection layer 4 is located on the bottom surface of the first step groove 31 and at least part of the side surface of the first step groove 31.

[0089] In one embodiment, the height of the grounding connection layer 4 is less than or equal to the side height of the first step groove 31. When the second step groove 32 is not provided, the height of the grounding connection layer 4 is less than the side height of the first step groove 31 and does not contact the pin.

[0090] In one embodiment, the ground connection layer 4 is a continuous annular connection ring arranged in a circumferential direction around the chip structure 2.

[0091] In one embodiment, the lead frame 1 is a leadless quad flat package lead frame (QFN lead frame 1), and the ground connection layer 4 is a rectangular ring structure adapted to the leadless quad flat package lead frame.

[0092] In another embodiment, the first step groove 31 includes a plurality of first step grooves 31 arranged circumferentially around the chip structure 2;

[0093] The grounding connection layer 4 has multiple blocks, and the multiple grounding connection layers 4 are correspondingly arranged with multiple first step grooves 31.

[0094] In another embodiment, the lead frame 1 may also be a lead frame 1 having single-sided or double-sided pins.

[0095] In one specific embodiment, a single-sided pin has multiple pins spaced apart.

[0096] In one embodiment, the lead frame 1 has at least one ground pin 12;

[0097] The grounding connection layer 4 has at least one, and the at least one grounding connection layer 4 is provided corresponding to the grounding pin 12.

[0098] In one embodiment, it also includes bonding wires 8, which are located within the molding compound 3;

[0099] The two ends of the bonding wire 8 are electrically connected to the pads on the upper surface of the chip structure 2 and the pins of the lead frame 1, respectively.

[0100] In one embodiment, an adhesive layer 7 is also included, through which the chip structure 2 is bonded to the upper surface of the base island 11.

[0101] In another embodiment, the chip structure 2 is flip-chip mounted on the upper surface of the pins of the lead frame 1, in which case the bonding wires 8 may not be required.

[0102] In one embodiment, the grounding connection layer 4 is a copper grounding connection layer, a gold grounding connection layer, an aluminum grounding connection layer, or a tungsten grounding connection layer.

[0103] Please refer to Figures 1-18 This application also provides a method for fabricating a lead frame packaging structure with electromagnetic shielding, comprising:

[0104] S100. Please refer to... Figure 3 The present invention provides a lead frame 1 and a chip structure 2. The lead frame 1 includes multiple frame units 100, and adjacent frame units 100 are connected by connecting ribs 14. Each frame unit 100 includes a base island 11 and ground pins 12 and non-ground pins 13 disposed on the outside of the base island 11. The chip structure 2 is disposed on the upper surface of the base island 11.

[0105] S200. Please refer to... Figure 4 and Figure 5 This forms a grounding wire 6, with both ends of the grounding wire 6 located on the same grounding pin 12 of the lead frame 1, and one end located on the side of the grounding pin 12 near the connecting rib 14.

[0106] In one embodiment, when the chip structure 2 is disposed on the upper surface of the base island 11 by bonding wire 8, the bonding wire 8 is further formed, and the two ends of the bonding wire 8 are electrically connected to the pads of the chip structure 2 and the pins of the lead frame 1, respectively.

[0107] In another embodiment, the chip structure 2 is disposed on the upper surface of the pin by flip-chip bonding, in which case the bonding wire 8 is not required.

[0108] S300. Please refer to... Figure 6 and Figure 7 An electromagnetic shielding connector 5 is formed, and the lower end of the electromagnetic shielding connector 5 is disposed on the upper surface of the pin of the lead frame 1.

[0109] In one embodiment, the grounding wire 6 is not in direct contact with the electromagnetic shielding connector 5.

[0110] In one embodiment, the electromagnetic shielding connector 5 consists of multiple connecting pillars vertically arranged relative to the grounding connection layer 4, with the multiple connecting pillars arranged circumferentially around the chip structure 2.

[0111] In one embodiment, the connecting post is bonded to the upper surface of the pin.

[0112] In another embodiment, the connecting post is welded to the upper surface of the pin.

[0113] Please refer to Figure 2 and Figure 7 In one embodiment, the lead frame 1 has a plurality of pins, and a plurality of connecting posts are provided corresponding to the plurality of pins.

[0114] Please refer to Figure 14 In another embodiment, the lead frame 1 has multiple pins and multiple connecting posts disposed on the upper surface of the connecting rib 14. The multiple connecting posts and the multiple pins do not need to be correspondingly disposed.

[0115] In another embodiment, the lead frame 1 has multiple pins, and the electromagnetic shielding connector 5 consists of multiple vertical solder wires. In this case, the multiple vertical solder wires are arranged corresponding to the multiple pins.

[0116] In another embodiment, the lead frame 1 has multiple pins, and the electromagnetic shielding connector 5 consists of multiple vertical solder wires. The multiple vertical solder wires are disposed on the upper surface of the connecting rib 14. In this case, the multiple vertical solder wires and the multiple pins do not need to be correspondingly disposed.

[0117] S400. Please refer to... Figure 8 A molding layer 3 is formed, which is located on the surface of the lead frame 1 and covers the chip structure 2, the ground wire 6 and the sidewall of the electromagnetic shielding connector 5.

[0118] In one embodiment, when the chip structure 2 is disposed on the upper surface of the base island 11 via bonding wires 8, the bonding wires 8 are located within the molding compound 3.

[0119] In one embodiment, when the upper end of the electromagnetic shielding connector 5 is covered with a plastic encapsulation layer 3, the process further includes grinding the plastic encapsulation layer 3 to expose the upper end of the electromagnetic shielding connector 5 outside the plastic encapsulation layer 3.

[0120] S500. Please refer to... Figure 9 An electromagnetic shielding layer 9 is formed, which is located on the surface of the encapsulation layer 3 away from the lead frame 1, and is electrically connected to the upper end of the electromagnetic shielding connector 5 away from the pin.

[0121] In one embodiment, an electromagnetic shielding layer 9 is formed on the surface of the molding layer 3 by magnetron sputtering.

[0122] In another embodiment, an electromagnetic shielding layer 9 is formed on the surface of the molding layer 3 by an electroplating process.

[0123] Please refer to Figure 16In one embodiment, a protective layer 10 is formed on the surface of the electromagnetic shielding layer 9.

[0124] Please refer to Figure 17 In another embodiment, the protective layer 10 is disposed on the sidewall and upper surface of the electromagnetic shielding layer 9. In this case, the outer periphery of the electromagnetic shielding layer 9 is first cut to expose the molding layer 3 at the edge of the electromagnetic shielding layer 9, and then the protective layer 10 is formed on the surface of the molding layer 3.

[0125] In one embodiment, the protective layer 10 is made of the same material as the molding layer 3.

[0126] In actual use, the step of forming the protective layer 10 can also be performed after the three-stage cutting process is completed.

[0127] S600. Please refer to... Figure 10 The first groove 33 is formed by a single cut. The first groove 33 is located on the side of the plastic encapsulation layer 3 near the lead frame 1. The bottom wall of the first groove 33 exposes the electromagnetic shielding connector 5 and / or the grounding wire 6. During the single cut, the connecting rib 14 of the lead frame 1, part of the electromagnetic shielding connector 5, part of the grounding wire 6 and / or part of the pins of the lead frame 1 are cut off.

[0128] The cutting width during a single cut is greater than the width of the connecting rib 14, and the cut extends to the pipe foot position.

[0129] In one embodiment, the first groove 33 is formed by a single cut using a photolithography process.

[0130] In another embodiment, the first groove 33 can also be formed by a single cut using a cutting tool.

[0131] S700. Please refer to... Figure 11 A grounding connection layer 4 is formed on the inner wall of the first groove 33, and the surface of the grounding connection layer 4 is electrically connected to the electromagnetic shielding connector 5 and / or the grounding wire 6.

[0132] In one embodiment, a grounding connection layer 4 is formed on the inner wall of the first groove 33 by a magnetron sputtering process.

[0133] In another embodiment, a grounding connection layer 4 is formed on the inner wall of the first groove 33 by an electroplating process.

[0134] In one embodiment, when the grounding connection layer 4 is formed on the inner wall of the first groove 33, the grounding connection layer 4 does not completely fill the first groove 33.

[0135] In another embodiment, when a grounding connection layer 4 is formed on the inner wall of the first groove 33, the grounding connection layer 4 fills the first groove 33.

[0136] S800. Please refer to... Figure 12The grounding connection layer 4 is cut a second time using a cutting tool so that the grounding connection layer 4 does not directly contact the pin.

[0137] The cutting width during the secondary cutting is equal to the width of the first groove 33, and the cutting thickness during the secondary cutting is less than the depth of the first groove 33. The part of the grounding connection layer 4 near the pin on the side wall of the first groove 33 is cut off, so that the grounding connection layer 4 is not directly conductively connected to the pin.

[0138] Please refer to Figure 15 In another embodiment, the cutting width during the secondary cutting is greater than the width of the first groove 33, and the cutting thickness during the secondary cutting is greater than or equal to the thickness of the pin and less than the depth of the first groove 33, so that the plastic encapsulation layer 3 forms a second groove 34 near the surface of the lead frame 1. The second groove 34 is closer to the lead frame 1 than the first groove 33, and the width of the second groove 34 is greater than the width of the first groove 33. During the secondary cutting, in addition to cutting off the ground connection layer 4 on the side of the pin and part of the ground connection layer 4 on the side wall of the plastic encapsulation layer 3 near the upper surface of the pin, part of the pin of the lead frame 1 and / or part of the plastic encapsulation layer 3 are also cut off.

[0139] At this point, after the secondary cutting process, the bottom wall of the first groove 33 forms the bottom surface of the first stepped groove 31, the side wall of the first groove 33 forms the side surface of the first stepped groove 31, the bottom wall of the second groove 34 forms the bottom surface of the second stepped groove 32, and the side wall of the second groove 34 forms the side surface of the second stepped groove 32.

[0140] S900. Please refer to... Figure 13 The bottom of the first groove 33 is cut three times to cut the plastic sealing layer 3, the electromagnetic shielding layer 9, the grounding connection layer 4 and the protective layer 10, forming a single electromagnetically shielded lead frame package structure, which is the electromagnetically shielded lead frame package structure described above.

[0141] The cutting width during the third cutting is less than the width of the first groove 33, so that the grounding connection layer 4 on the bottom surface of the first groove 33 is not completely cut off.

[0142] In one embodiment, since the pin surfaces of existing lead frames require soldering of bonding wires, the pin surfaces of existing lead frames have a solderable plating. When the ground wire and vertical solder wire are wired to the lead frame, both ends of the ground wire and vertical solder wire are wired to the pin surface. Since it is not necessary to wire the surface of the connecting ribs of the lead frame, there is no need to form an additional solderable plating on the surface of the connecting ribs of the lead frame, resulting in lower cost.

[0143] In one embodiment, the solderable coating is a silver plating layer.

[0144] It should be noted that, where there is no conflict, the features in the different embodiments of this application described above can be combined with each other. Furthermore, in each of the above embodiments, the focus is on describing the differences from other embodiments; other specific descriptions of the same / similar parts between the embodiments can be referred to (or referenced) interchangeably. In addition, descriptions of well-known components and technologies have been omitted in the above description to avoid unnecessarily obscuring the concepts of this application.

[0145] Although this application has been disclosed above with reference to preferred embodiments, it is not intended to limit this application. Any person skilled in the art can make possible changes and modifications to the technical solutions of this application by utilizing the methods and techniques disclosed above without departing from the spirit and scope of this application. Therefore, any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of this application without departing from the content of the technical solutions of this application shall fall within the protection scope of the technical solutions of this application.

Claims

1. A leadframe package structure with electromagnetic shielding, characterized by, include: A lead frame, the lead frame including a base island and pins disposed outside the base island, the pins including grounded pins and non-grounded pins; A chip structure, wherein the chip structure is disposed on the upper surface of the base island; A molding layer is located on the surface of the lead frame and covers the chip structure, and exposes the lower surface of the lead frame. The molding layer has a first stepped groove on its sidewall near the upper surface of the lead frame. A grounding connection layer is located on the bottom wall of the first step groove, and the grounding connection layer is not in direct contact with the pin. An electromagnetic shielding layer, wherein the electromagnetic shielding layer is located on the surface of the encapsulation layer away from the lead frame; An electromagnetic shielding connector is located within the plastic encapsulation layer. One end of the electromagnetic shielding connector is electrically connected to the upper surface of the grounding connection layer, and the other end is electrically connected to the lower surface of the electromagnetic shielding layer. A grounding wire is located within the plastic encapsulation layer. The two ends of the grounding wire are electrically connected to the upper surface of the grounding connection layer and the upper surface of the grounding pin of the lead frame, respectively, so as to ground the electromagnetic shielding layer and the electromagnetic shielding connector.

2. The leadframe package structure with electromagnetic shielding of claim 1, wherein, The electromagnetic shielding connector is a connecting post or a vertical welding wire that is perpendicular to the grounding connection layer.

3. The leadframe package structure with electromagnetic shielding of claim 1, wherein, The electromagnetic shielding connectors include multiple components, which are arranged circumferentially around the chip structure.

4. The leadframe package structure with electromagnetic shielding of claim 3, wherein, The lead frame has multiple pins, and multiple electromagnetic shielding connectors are provided corresponding to the multiple pins.

5. The lead frame packaging structure with electromagnetic shielding as described in claim 1, characterized in that, It also includes a protective layer located on the surface of the electromagnetic shielding layer.

6. The leadframe package structure with electromagnetic shielding of claim 1, wherein, The molding layer has a second stepped groove on the surface near the lead frame, and the first stepped groove is located at the bottom of the second stepped groove. The second stepped groove is used to prevent the grounding connection layer from directly contacting the pin.

7. The leadframe package structure with electromagnetic shielding of claim 6, wherein, The first step groove and the second step groove are respectively annular step grooves arranged in a circumferential direction around the chip structure.

8. The leadframe package structure with electromagnetic shielding of claim 6, wherein, The horizontal plane at which the bottom surface of the second step groove is located is at least lower than the horizontal plane at which the upper surface of the chip structure on the side away from the lead frame is located.

9. The leadframe package structure with electromagnetic shielding of claim 6, wherein, The bottom surface of the second step groove is at a horizontal level that is higher than or level with the upper surface of the lead frame pins on the side closest to the chip structure.

10. The leadframe package structure with electromagnetic shielding of claim 1, wherein, The grounding connection layer is a continuous annular connection ring arranged in a circumferential direction around the chip structure.

11. The lead frame packaging structure with electromagnetic shielding as described in claim 1, characterized in that, The first step groove includes multiple first step grooves, which are arranged circumferentially around the chip structure; The grounding connection layer has multiple blocks, and each block of the grounding connection layer is correspondingly arranged with multiple first step grooves.

12. The leadframe package structure with electromagnetic shielding of claim 1, wherein, The lead frame has at least one ground pin; The grounding connection layer has at least one piece, and at least one grounding connection layer is provided corresponding to the grounding pin.

13. The leadframe package structure with electromagnetic shielding of claim 1, wherein, The grounding connection layer is located on the bottom surface of the first stepped groove and at least part of the side surface of the first stepped groove.

14. The leadframe package structure with electromagnetic shielding of claim 1, wherein, The height of the grounding connection layer is less than or equal to the side height of the first step groove.

15. The leadframe package structure with electromagnetic shielding of claim 1, wherein, It also includes bonding wires, which are located within the molding layer; Two ends of the bonding wire are electrically connected with the pad on the upper surface of the chip structure and the pin of the lead frame respectively.

16. The leadframe package structure with electromagnetic shielding of claim 1, wherein, The chip structure is inversely set on the upper surface of the pin.

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