Electromagnetic shielding package structure

Abstract

The application provides an electromagnetic shielding packaging structure, which comprises a lead frame with a base island and pins, the pins comprising ground pins and non-ground pins; a chip structure arranged on the upper surface of the base island; a plastic packaging layer covering the chip structure; an electromagnetic shielding layer arranged on the sidewall of the plastic packaging layer, the electromagnetic shielding layer not being in direct contact with the pins; an electromagnetic shielding wire electrically connected to the sidewall of the electromagnetic shielding layer close to the chip structure; and a ground wire electrically connected to the sidewall of the electromagnetic shielding layer close to the chip structure and the ground pins respectively. The structure is arranged in such a way that the electromagnetic shielding structure can be formed by wire bonding in the packaging structure of the lead frame, and the electromagnetic shielding wires do not need to be connected by direct contact structure, so that the wire bonding difficulty of the electromagnetic shielding wires can be reduced.

Description

Technical Field

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

[0002] Electromagnetic shielding layers 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 layers block these 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, interference between chips can lead to signal transmission errors and logic gate malfunctions. Electromagnetic shielding layers 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 layers 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 layers 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 layers 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 an electromagnetic shielding packaging structure that enables the formation of an electromagnetic shielding layer on a lead frame packaging structure by wire bonding.

[0005] To address the above problems, this application provides an electromagnetic shielding encapsulation structure, 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 compound layer is located on the surface of the lead frame and covers the chip structure.

[0009] An electromagnetic shielding layer is located on the side wall of the molding layer near the lead frame, and the electromagnetic shielding layer is not in direct contact with the pin.

[0010] An electromagnetic shielding wire is located within the molding compound and spans across the chip structure on the side away from the lead frame, and the ends of the electromagnetic shielding wire are electrically connected to the sidewall of the electromagnetic shielding layer on the side closer to the chip structure.

[0011] A grounding wire, the two ends of which are electrically connected to the sidewall of the electromagnetic shielding layer near the chip structure and at least one grounding pin of the lead frame, respectively.

[0012] This application forms an electromagnetic shielding layer on the sidewall of the molding compound, electrically connecting the ends of the electromagnetic shielding wires to the opposite sidewalls of the electromagnetic shielding layer. A grounding wire electrically connects the electromagnetic shielding layer and the grounding pin of the lead frame, allowing the electromagnetic shielding wires to be sequentially connected to the grounding pin of the lead frame via the electromagnetic shielding layer and the grounding wire, thereby forming electromagnetic shielding above the chip structure. In other words, this structural design allows the electromagnetic shielding structure to be formed within the lead frame package structure via wire bonding (electromagnetic shielding wires).

[0013] In an optional embodiment, the molding compound has a first stepped groove at the edge of the surface near the lead frame, and the electromagnetic shielding layer is located on the sidewall surface of the first stepped groove of the molding compound.

[0014] In an optional embodiment, the molding compound has a second stepped groove on its edge near the lead frame side surface, with the first stepped groove located at the bottom of the second stepped groove. This second stepped groove prevents the electromagnetic shielding layer from directly contacting the pins.

[0015] By forming a first step groove and a second step groove on the molding layer, an electromagnetic shielding layer is formed on the surface of the first step groove, and the second step groove can block the connection between the electromagnetic shielding layer and the other pins of the lead frame except for the ground pin.

[0016] In an optional embodiment, the first stepped groove and the second stepped groove are respectively annular grooves arranged in a circumferential direction around the chip structure;

[0017] The electromagnetic shielding layer is a continuous annular shielding ring arranged in a circumferential direction around the chip structure.

[0018] By setting a continuous annular electromagnetic shielding layer around the chip structure, the outer periphery of the chip structure has continuous electromagnetic shielding, thereby giving the packaging structure a better electromagnetic shielding effect.

[0019] In an optional embodiment, the first stepped groove includes a plurality of first stepped grooves arranged circumferentially around the chip structure;

[0020] The electromagnetic shielding layer comprises multiple blocks, and each block of the electromagnetic shielding layer is correspondingly arranged with multiple first step grooves.

[0021] In an optional embodiment, the electromagnetic shielding 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.

[0022] 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.

[0023] In an optional embodiment, the height of the electromagnetic shielding layer is less than or equal to the side height of the first stepped groove.

[0024] In an optional embodiment, the bottom surface of the second stepped groove is at a level higher than or level with the lower surface of the lead frame pins on the side closest to the chip structure.

[0025] In an optional embodiment, the horizontal plane containing the bottom surface of the first stepped groove is higher than the horizontal plane containing the upper surface of the chip structure on the side away from the lead frame.

[0026] In an optional embodiment, it further includes bonding wires located within the molding compound;

[0027] The two ends of the bonding wire are electrically connected to the pins of the chip structure and the lead frame, respectively.

[0028] In an alternative embodiment, the chip structure is flip-chip mounted on the upper surface of the pins of the lead frame.

[0029] In an optional embodiment, the chip structure has pads on the surface away from the base island, and the bonding wires are electrically connected to the chip structure through the pads.

[0030] In an optional embodiment, the electromagnetic shielding wire includes multiple single wires, the two ends of which are electrically connected to the sidewall of the electromagnetic shielding layer near the chip structure, respectively, and the multiple single wires, the electromagnetic shielding layer, the grounding wire, and the grounding pin are grounded.

[0031] In an optional embodiment, the multiple single-wire bodies are arranged in a grid pattern.

[0032] In an alternative embodiment, the multiple single wires may or may not be in contact at the locations where they form cross nodes.

[0033] In an optional embodiment, the electromagnetic shielding wire is located within the encapsulation layer.

[0034] In an optional embodiment, the lead frame is a leadless quad flat package lead frame.

[0035] In an optional embodiment, the electromagnetic shielding layer is a rectangular ring structure adapted to the leadless quad flat package lead frame.

[0036] In an optional embodiment, the electromagnetic shielding layer is a copper electromagnetic shielding layer, a gold electromagnetic shielding layer, an aluminum electromagnetic shielding layer, or a ferrite electromagnetic shielding layer.

[0037] In an optional embodiment, an adhesive layer is further included, which is disposed between the base island of the lead frame and the chip structure, the chip structure being bonded to the upper surface of the base island via the adhesive layer.

[0038] The advantages of the technical solution in this application are:

[0039] This application forms an electromagnetic shielding layer on the sidewall of the molding compound, electrically connecting the ends of the electromagnetic shielding wires to the opposite sidewalls of the electromagnetic shielding layer. A grounding wire is then used to electrically connect the electromagnetic shielding layer and the grounding pin of the lead frame. This allows the electromagnetic shielding wires to be sequentially electrically connected to the grounding pin of the lead frame via the electromagnetic shielding layer and the grounding wire (all electromagnetic shielding wires are interconnected and grounded), thus forming electromagnetic shielding above the chip structure. This structural design allows the electromagnetic shielding structure to be formed within the lead frame package structure using wire bonding (electromagnetic shielding wires). Furthermore, the electromagnetic shielding wires do not need to be directly grounded, significantly reducing the difficulty of wire bonding.

[0040] Furthermore, by forming a first step groove and a second step groove on the molding layer, an electromagnetic shielding layer is formed on the surface of the first step groove, and the second step groove can block the connection between the electromagnetic shielding layer and the other pins of the lead frame except for the ground pin.

[0041] Furthermore, by setting a continuous annular electromagnetic shielding layer around the chip structure, the outer periphery of the chip structure can have continuous electromagnetic shielding. Combined with the electromagnetic shielding line on the 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. Attached Figure Description

[0042] 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.

[0043] Figure 1 This is a top view of an embodiment of the electromagnetic shielding encapsulation structure of this application (components such as the electromagnetic shielding layer are drawn as shown).

[0044] Figure 2 This is a schematic diagram of the electromagnetic shielding encapsulation structure along A1-A2 according to an embodiment of this application;

[0045] Figure 3 This is a schematic diagram of a method for forming an electromagnetic shielding encapsulation structure in one embodiment of this application. Figure 1 ;

[0046] Figure 4 This is a schematic diagram of a method for forming an electromagnetic shielding encapsulation structure in one embodiment of this application. Figure 2 ;

[0047] Figure 5 for Figure 4 Corresponding top view structural diagram (and Figure 4 for Figure 5 (Cross-section view along B1-B2)

[0048] Figure 6 This is a schematic diagram of a method for forming an electromagnetic shielding encapsulation structure in one embodiment of this application. Figure 3 ;

[0049] 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)

[0050] Figure 8 This is a schematic diagram of a method for forming an electromagnetic shielding encapsulation structure in one embodiment of this application. Figure 4 ;

[0051] Figure 9 This is a schematic diagram of a method for forming an electromagnetic shielding encapsulation structure in one embodiment of this application. Figure 5 ;

[0052] Figure 10This is a schematic diagram of a method for forming an electromagnetic shielding encapsulation structure in one embodiment of this application. Figure 6 ;

[0053] Figure 11 This is a schematic diagram of a method for forming an electromagnetic shielding encapsulation structure in one embodiment of this application. Figure 7 ;

[0054] Figure 12 This is a schematic diagram of a method for forming an electromagnetic shielding encapsulation structure in one embodiment of this application. Figure 8 ;

[0055] Figure 13 This is a top view of another embodiment of the electromagnetic shielding encapsulation structure of this application (components such as the electromagnetic shielding layer are drawn as shown).

[0056] Figure 14 This is a schematic diagram of the electromagnetic shielding encapsulation structure from the front view of another embodiment of this application;

[0057] Figure 15 This is a schematic diagram of the electromagnetic shielding packaging structure from the front view, representing another embodiment of this application.

[0058] The labels for the attached figures are as follows:

[0059] 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. Electromagnetic shielding layer; 5. Electromagnetic shielding wire; 6. Grounding wire; 7. Adhesive layer; 8. Bonding wire; 100. Frame unit. Detailed Implementation

[0060] 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.

[0061] 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.

[0062] 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.

[0063] 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.

[0064] 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.

[0065] 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).

[0066] This application provides an electromagnetic shielding packaging structure, in conjunction with reference to... Figures 1-14 ,in Figure 1 This is a top view of an embodiment of the electromagnetic shielding encapsulation structure of this application; Figure 2 This is a schematic diagram of the electromagnetic shielding encapsulation structure along A1-A2 according to an embodiment of this application; Figure 3 This is a schematic diagram of a method for forming an electromagnetic shielding encapsulation structure in one embodiment of this application. Figure 1 ; Figure 4 This is a schematic diagram of a method for forming an electromagnetic shielding encapsulation structure 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 an electromagnetic shielding encapsulation structure 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 an electromagnetic shielding encapsulation structure in one embodiment of this application. Figure 4 ; Figure 9 This is a schematic diagram of a method for forming an electromagnetic shielding encapsulation structure in one embodiment of this application. Figure 5 ; Figure 10 This is a schematic diagram of a method for forming an electromagnetic shielding encapsulation structure in one embodiment of this application. Figure 6 ; Figure 11 This is a schematic diagram of a method for forming an electromagnetic shielding encapsulation structure in one embodiment of this application. Figure 7 ; Figure 12 This is a schematic diagram of a method for forming an electromagnetic shielding encapsulation structure in one embodiment of this application. Figure 8 ; Figure 13 This is a top view of another embodiment of the electromagnetic shielding encapsulation structure of this application (components such as the electromagnetic shielding layer are drawn as shown). Figure 14 , Figure 15 These are schematic diagrams of the electromagnetic shielding packaging structure from the front view, representing another embodiment of this application; the electromagnetic shielding packaging structure includes:

[0067] 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.

[0068] Chip structure 2 is disposed on the upper surface of base island 11;

[0069] A molding layer 3 is located on the surface of the lead frame 1 and covers the chip structure 2;

[0070] Electromagnetic shielding layer 4 is located on the side wall of the plastic encapsulation layer 3 near the lead frame 1, and the electromagnetic shielding layer 4 does not directly contact the pins of the lead frame 1.

[0071] Electromagnetic shielding wire 5 is located inside the molding layer 3 and spans across the chip structure 2 on the side away from the lead frame 1. The ends of the electromagnetic shielding wire 5 are electrically connected to the sidewall of the electromagnetic shielding layer 4, which is disposed opposite to the chip structure.

[0072] Grounding wire 6, with its two ends electrically connected to at least one grounding pin 12 of the electromagnetic shielding layer 4 on the side wall near the chip structure and the lead frame 1, respectively.

[0073] 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.

[0074] This application forms an electromagnetic shielding layer 4 on the sidewall of the molding layer 3, electrically connecting the ends of the electromagnetic shielding wires 5 to the opposite sidewalls of the electromagnetic shielding layer 4. A grounding wire 6 is then used to electrically connect the electromagnetic shielding layer 4 and the grounding pin 12 of the lead frame 1. This allows the electromagnetic shielding wires 5 to be electrically connected to the grounding pin 12 of the lead frame 1 sequentially through the electromagnetic shielding layer 4 and the grounding wire 6, thereby forming electromagnetic shielding above the chip structure 2. In other words, this structural arrangement allows the electromagnetic shielding structure to be formed within the lead frame's packaging structure via wire bonding (electromagnetic shielding wires 5).

[0075] In one embodiment, the molding layer 3 has a first stepped groove 31 on the edge of the surface near the lead frame 1, and the electromagnetic shielding layer 4 is located on the sidewall surface of the first stepped groove 31 of the molding layer 3.

[0076] In one embodiment, the surface of the molding layer 3 further has a second stepped groove 32, which is disposed near the surface of the molding layer 3 near the lead frame 1, and the first stepped groove 31 is located at the bottom of the second stepped groove 32.

[0077] The second step groove 32 is used to prevent the electromagnetic shielding layer 4 from directly contacting the pin.

[0078] By forming a first stepped groove 31 and a second stepped groove 32 on the plastic encapsulation layer 3, an electromagnetic shielding layer 4 is formed on the surface of the first stepped groove 31, and the second stepped groove 32 can block the connection between the electromagnetic shielding layer 4 and the other pins of the lead frame 1 except for the ground pin 12.

[0079] Please refer to Figure 14 In another embodiment, the surface of the molding layer 3 has a first stepped groove 31 but no second stepped groove 32. The height of the electromagnetic shielding layer 4 is less than the height of the first stepped groove 31, and the electromagnetic shielding layer 4 does not directly contact the pin.

[0080] Please refer to Figure 15 In another embodiment, the surface of the molding layer 3 may not have the first step groove 31 and the second step groove 32, and the electromagnetic shielding layer 4 is located directly on the side wall surface of the molding layer 3 near the lead frame 1, and the electromagnetic shielding layer 4 is not in direct contact with the pin.

[0081] In one embodiment, the first step groove 31 and the second step groove 32 are respectively annular grooves arranged in a circumferential direction around the chip structure 2;

[0082] The electromagnetic shielding layer 4 is a continuous annular shielding ring arranged in a circumferential direction around the chip structure 2.

[0083] By setting a continuous annular electromagnetic shielding layer 4 around the chip structure 2, the outer periphery of the chip structure 2 has continuous electromagnetic shielding, thereby giving the packaging structure a better electromagnetic shielding effect.

[0084] In another embodiment, the first step groove 31 includes a plurality of first step grooves 31 arranged circumferentially around the chip structure 2;

[0085] The electromagnetic shielding layer 4 has multiple pieces, and the multiple electromagnetic shielding layers 4 are correspondingly arranged with multiple first step grooves 31.

[0086] Please refer to Figure 13 In one specific embodiment, the first step groove 31 includes four, and the four first step grooves 31 are respectively located on the four sides of the chip structure 2. The four electromagnetic shielding layers 4 are arranged circumferentially around the chip structure 2. At this time, the electromagnetic shielding lines 5 that cross each other are electrically connected to each other, so that the multiple electromagnetic shielding lines 5 and the four electromagnetic shielding layers 4 are connected to the grounding pin 12 through at least one grounding wire 6.

[0087] In another specific embodiment, the first step groove 31 includes four, and the four first step grooves 31 are respectively located on the four sides of the chip structure 2. The four electromagnetic shielding layers 4 are arranged circumferentially around the chip structure 2. The electromagnetic shielding lines 5 can be arranged without contact. At this time, at least one of the two electromagnetic shielding layers 4 connected at both ends of each electromagnetic shielding line 5 is grounded to the ground pin 12 through the grounding wire 6.

[0088] In one embodiment, neither the side surface of the second step groove 32 nor the bottom surface of the second step groove 32 has the electromagnetic shielding layer 4.

[0089] In one embodiment, the electromagnetic shielding layer 4 is located on the bottom surface of the first step groove 31 and is in contact with all or part of the side surface of the first step groove 31.

[0090] In other embodiments, the electromagnetic shielding layer 4 is located on the bottom surface of the first stepped groove 31 and all sides of the first stepped groove 31.

[0091] In one embodiment, the electromagnetic shielding layer 4 is a copper electromagnetic shielding layer, a gold electromagnetic shielding layer, an aluminum electromagnetic shielding layer, or a ferrite electromagnetic shielding layer.

[0092] 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.

[0093] In one embodiment, the bottom surface of the second step groove 32 is at a horizontal level that is higher than or level with the surface of the lead frame 1 on the side of the lead frame 1 closest to the chip structure 2.

[0094] In one embodiment, it also includes bonding wires 8, which are located within the molding compound 3;

[0095] The two ends of the bonding wire 8 are electrically connected to the pins of the chip structure 2 and the lead frame 1, respectively.

[0096] In another embodiment, the chip structure 2 is disposed on the upper surface of the pins by flip-chip bonding, in which case there is no need to provide bonding wires 8.

[0097] In one embodiment, a pad is provided on the side surface of the chip structure 2 away from the base island 11, and the bonding wire 8 is electrically connected to the chip structure 2 through the pad.

[0098] In one embodiment, the electromagnetic shielding wire 5 includes multiple single wires, the two ends of which are electrically connected to the electromagnetic shielding layers 4 on opposite sides of the chip structure 2. The electromagnetic shielding wire 5, the electromagnetic shielding layers 4, the grounding wire 6, and the grounding pin 12 are grounded.

[0099] In one embodiment, multiple single-wire bodies are arranged in a grid pattern.

[0100] In another embodiment, the multiple single-line bodies are arranged in a parallel line structure.

[0101] In one embodiment, multiple single wires may or may not be in contact at the locations where they form cross nodes.

[0102] In one embodiment, the lead frame 1 is a leadless quad flat package lead frame (QFN lead frame).

[0103] In one specific embodiment, a single-sided pin has multiple pins spaced apart.

[0104] In another embodiment, the lead frame 1 may also be a lead frame with single-sided or double-sided pins.

[0105] In one embodiment, the non-grounded pin 13 includes a plurality of pins.

[0106] In one embodiment, the electromagnetic shielding layer 4 is a rectangular ring structure adapted to the lead frame of a leadless quad flat package.

[0107] In one embodiment, an adhesive layer 7 is also included, through which the chip structure 2 is bonded to the surface of the base island 11.

[0108] Please refer to Figures 2-15 This application also provides a method for preparing an electromagnetic shielding packaging structure, comprising:

[0109] 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 pins disposed on the outside of the base island 11. The pins include ground pins 12 and non-ground pins 13. The chip structure 2 is disposed on the upper surface of the base island 11.

[0110] S200. Please refer to... Figure 4 and Figure 5 A grounding wire 6 is formed, with the two ends of the grounding wire 6 located on the upper surface of the connecting rib 14 of the lead frame 1 and the upper surface of the grounding pin 12 of the lead frame 1, respectively, or the two ends of the grounding wire 6 located on the upper surfaces of the two grounding pins 12 of the adjacent lead frame unit.

[0111] In another embodiment, the two ends of the grounding wire 6 may also be located on the same grounding pin 12 of the lead frame unit, with one end located on the side of the grounding pin 12 near the connecting rib 14.

[0112] S300. Please refer to... Figure 6 and Figure 7An electromagnetic shielding line 5 is formed, which is laid across the chip structure 2 on the side away from the lead frame 1. The two ends of the electromagnetic shielding line 5 are located on the upper surface of the connecting rib 14 of the lead frame 1 or on the upper surface of the pin of the lead frame 1, respectively. When the end of the electromagnetic shielding line 5 is located on the upper surface of the pin of the lead frame 1, the end of the electromagnetic shielding line 5 is located on the side of the upper surface of the pin close to the connecting rib 14.

[0113] In one embodiment, when the chip structure 2 is disposed on the upper surface of the base island 11, before forming the electromagnetic shielding line 5, a bonding line 8 is also formed, and the two ends of the bonding line 8 are electrically connected to the pads of the chip structure 2 and the pins of the lead frame 1, respectively.

[0114] In another embodiment, the chip structure 2 is disposed on the upper surface of the pins by flip-chip bonding, in which case bonding wires 8 are not required.

[0115] 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, electromagnetic shielding line 5, grounding line 6 and bonding line 8.

[0116] In one embodiment, when the chip structure 2 is disposed on the upper surface of the base island 11, the bonding wire 8 is located within the molding layer 3.

[0117] S500. Please refer to... Figure 9 A first groove 33 is formed by a single cut (back cut). The first groove 33 is located on the side of the plastic encapsulation layer 3 near the lead frame 1. The sidewall of the first groove 33 exposes the electromagnetic shielding wire 5 and the grounding wire 6. During the single cut, the connecting rib 14 of the lead frame 1, part of the electromagnetic shielding wire 5, part of the grounding wire 6 and / or part of the pins of the lead frame 1 are cut off.

[0118] The cutting width during a single cut is greater than or equal to the width of the connecting rib 14.

[0119] In one embodiment, the first groove 33 is formed by a single cut using a cutting tool.

[0120] S600. Please refer to... Figure 10 An electromagnetic shielding layer 4 is formed on the inner wall of the first groove 33, and the sidewall of the electromagnetic shielding layer 4 is electrically connected to the electromagnetic shielding line 5 and / or the grounding line 6.

[0121] In one embodiment, an electromagnetic shielding layer 4 is formed on the inner wall of the first groove 33 by magnetron sputtering.

[0122] In one embodiment, when the electromagnetic shielding layer 4 is formed on the inner wall of the first groove 33, the electromagnetic shielding layer 4 does not completely fill the first groove 33.

[0123] In another embodiment, when an electromagnetic shielding layer 4 is formed on the inner wall of the first groove 33, the electromagnetic shielding layer 4 fills the first groove 33 completely.

[0124] S700. Please refer to... Figure 11 The pins, encapsulation layer 3, and electromagnetic shielding layer 4 are cut a second time using a cutting tool to form a second groove 34. The second groove 34 is located on the side of the encapsulation layer 3 closer to the lead frame 1 and is closer to the lead frame 1 than the first groove 33. The width of the second groove 34 is greater than or equal to the width of the first groove 33. When the width of the second groove 34 is equal to the width of the first groove 33, the electromagnetic shielding layer 4 on the side of the pin and part of the electromagnetic shielding layer 4 near the upper surface of the pin are cut off during the secondary cutting process. When the width of the second groove 34 is greater than the width of the first groove 33, in addition to cutting off the electromagnetic shielding layer 4 on the side of the pin and part of the electromagnetic shielding layer 4 near the upper surface of the pin, part of the pin and / or part of the plastic seal 3 of the lead frame 1 are also cut off during the secondary cutting process. 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.

[0125] The cutting width during the secondary cutting is greater than or equal to the width of the first groove 33, and the cutting thickness during the secondary cutting is greater than the thickness of the pin, so that the electromagnetic shielding layer 4 is not directly electrically connected to the pin.

[0126] Please refer to Figure 14 In another embodiment, the cutting width during the secondary cutting can also be equal to the width of the first groove 33 (without the second groove 34), cutting off part of the electromagnetic shielding layer 4 on the sidewall of the first groove 33 and near the pin position, so that the electromagnetic shielding layer 4 is not directly electrically connected to the pin.

[0127] S800. Please refer to... Figure 12 The bottom of the first groove 33 is cut three times to cut the plastic encapsulation layer 3 and the electromagnetic shielding layer 4, forming a single electromagnetic shielding encapsulation structure, which is the electromagnetic shielding encapsulation structure described above.

[0128] The cutting width during the three cuts is less than the width of the first groove 33, so that the electromagnetic shielding layer 4 on the surface of the first groove 33 is not completely cut off.

[0129] In another embodiment, the molding layer 3 at the bottom of the first groove 33 is cut three times from the surface of the molding layer 3 away from the lead frame. The width of each cut is equal to the width of the first groove 33, ultimately severing the molding layer 3 and the electromagnetic shielding layer 4, forming a shape as shown in the image. Figure 15The single electromagnetic shielding encapsulation structure (the cutting width during the secondary cutting is also equal to the width of the first groove 33).

[0130] 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.

[0131] 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. An electromagnetic shielding packaging structure, characterized in that, 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 compound layer, which is located on the surface of the lead frame and covers the chip structure; An electromagnetic shielding layer is located on the side wall of the molding layer near the lead frame, and the electromagnetic shielding layer is not in direct contact with the pin. An electromagnetic shielding wire is located within the molding compound and spans across the chip structure on the side away from the lead frame, and the ends of the electromagnetic shielding wire are electrically connected to the sidewall of the electromagnetic shielding layer on the side closer to the chip structure. A grounding wire, the two ends of which are electrically connected to the sidewall of the electromagnetic shielding layer near the chip structure and at least one grounding pin of the lead frame, respectively.

2. The electromagnetic shielding packaging structure as described in claim 1, characterized in that, The molding layer has a first stepped groove at the edge of the surface near the lead frame, and the electromagnetic shielding layer is located on the sidewall surface of the first stepped groove of the molding layer.

3. The electromagnetic shielding packaging structure as described in claim 2, characterized in that, The first step groove includes multiple first step grooves, which are arranged circumferentially around the chip structure; The electromagnetic shielding layer comprises multiple blocks, and each block of the electromagnetic shielding layer is correspondingly arranged with multiple first step grooves.

4. The electromagnetic shielding packaging structure as described in claim 2, characterized in that, The electromagnetic shielding layer is located on the bottom surface of the first step groove and at least part of the side surface of the first step groove.

5. The electromagnetic shielding packaging structure as described in claim 2, characterized in that, The molding layer has a second stepped groove on the edge of 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 electromagnetic shielding layer from directly contacting the pin.

6. The electromagnetic shielding packaging structure as described in claim 3, characterized in that, The first step groove and the second step groove are respectively annular grooves arranged in a circumferential direction around the chip structure.

7. The electromagnetic shielding packaging structure as described in claim 3, characterized in that, 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.

8. The electromagnetic shielding packaging structure as described in claim 7, characterized in that, The height of the electromagnetic shielding layer is less than or equal to the side height of the groove in the first step.

9. The electromagnetic shielding packaging structure as described in claim 3, characterized in that, The bottom surface of the second step groove is at a horizontal level that is higher than or level with the surface of the pin on the side closest to the chip structure.

10. The electromagnetic shielding packaging structure as described in claim 1, characterized in that, The electromagnetic shielding layer is a continuous annular shielding ring arranged in a circumferential direction around the chip structure.

11. The electromagnetic shielding packaging structure as described in claim 1, characterized in that, It also includes bonding wires, which are located within the molding layer; The two ends of the bonding wire are respectively connected to the pads on the surface of the chip structure and the pins of the lead frame.

12. The electromagnetic shielding packaging structure as described in claim 1, characterized in that, The chip structure is flip-chip mounted on the upper surface of the pins of the lead frame.

13. The electromagnetic shielding packaging structure as described in claim 1, characterized in that, The electromagnetic shielding wire includes multiple single wires, the two ends of which are electrically connected to the sidewall of the electromagnetic shielding layer near the chip structure. The multiple single wires, the electromagnetic shielding layer, the grounding wire, and the grounding pin are all grounded.

14. The electromagnetic shielding packaging structure as described in claim 13, characterized in that, Multiple single-line bodies are arranged in a grid pattern; Multiple single wires may or may not make contact at the points where they form intersections.

15. The electromagnetic shielding packaging structure as described in claim 1, characterized in that, The electromagnetic shielding layer is a rectangular annular shielding ring.

16. The electromagnetic shielding packaging structure as described in claim 1, characterized in that, The electromagnetic shielding layer is a copper electromagnetic shielding layer, a gold electromagnetic shielding layer, an aluminum electromagnetic shielding layer, or a ferrite electromagnetic shielding layer.

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