Electromagnetic shielding package structure

Abstract

The application provides an electromagnetic shielding packaging structure, which comprises a lead frame with a base island and a pin; a chip structure arranged on the surface of the base island; a plastic packaging layer arranged on the surface of the lead frame and covering the chip structure, wherein a first step groove is formed on the surface of the plastic packaging layer close to the lead frame, and the bottom surface of the first step groove is a certain distance away from the pin of the lead frame; an electromagnetic shielding layer arranged on the surface of the first step groove; an electromagnetic shielding wire arranged on the side of the chip structure away from the lead frame, and the electromagnetic shielding wire is electrically connected with the electromagnetic shielding layer; and a grounding wire, the two ends of the grounding wire are electrically connected with the electromagnetic shielding layer and the grounding pin respectively. Through the structure, the electromagnetic shielding structure can be formed by wire bonding in the lead frame packaging structure, and the electromagnetic shielding wires do not need to be grounded by direct contact, which can greatly reduce the wire bonding difficulty of the electromagnetic shielding wires.

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. Utility Model Content

[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 is located on the upper surface of the lead frame and covers the chip structure. The molding compound has a first stepped groove on the edge of the surface away from the lead frame. The bottom surface of the first stepped groove is at a certain distance from the pins of the lead frame.

[0009] An electromagnetic shielding layer, wherein the electromagnetic shielding layer is located on the surface of the groove of the first step;

[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. The ends of the electromagnetic shielding wire are electrically connected to the opposite electromagnetic shielding layer.

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

[0012] By forming a first stepped groove on the molding compound, and then forming an electromagnetic shielding layer on the first stepped groove, and electrically connecting the electromagnetic shielding layer and the grounding pin of the leadframe via a grounding wire, the electromagnetic shielding wire can be electrically connected to the grounding pin of the leadframe sequentially through the electromagnetic shielding layer and the electromagnetic shielding 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 leadframe package structure via wire bonding (electromagnetic shielding wire).

[0013] In an optional embodiment, the first stepped groove is an annular groove arranged circumferentially around the chip structure;

[0014] The electromagnetic shielding layer is a continuous annular shielding ring arranged in a circumferential direction around the chip structure.

[0015] 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.

[0016] The first step groove includes multiple first step grooves, which are arranged circumferentially around the chip structure;

[0017] The electromagnetic shielding layer comprises multiple blocks, and each block of the electromagnetic shielding layer is correspondingly arranged with multiple first step grooves.

[0018] 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.

[0019] In an optional embodiment, the horizontal plane containing the bottom surface of the first 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 this application, the upper surface of the chip structure refers to the surface of the chip structure away from the lead frame, and the lower surface of the chip structure refers to the surface of the chip structure close to the lead frame.

[0021] In an optional embodiment, the horizontal plane of the bottom surface of the first stepped groove is lower than the horizontal plane of the lower surface of the chip structure near the lead frame, or coincides with the horizontal plane of the lower surface of the chip structure near the lead frame.

[0022] In an optional embodiment, a plastic sealing layer of a certain thickness is spaced between the bottom surface of the first stepped groove and the upper surface of the lead frame.

[0023] In an alternative embodiment, a first stepped groove is located above the ungrounded pin and the grounded pin, and a plastic seal is provided between the bottom surface of the first stepped groove and the upper surface of the ungrounded pin and the grounded pin.

[0024] In an optional embodiment, it further includes bonding wires located within the molding compound;

[0025] The two ends of the bonding wire are electrically connected to the pins (grounded pins and / or ungrounded pins) of the chip structure and the lead frame, respectively.

[0026] In an optional embodiment, the first stepped groove is located above the ungrounded pin and the grounded pin;

[0027] The width of the first step groove is less than the length of the tube foot.

[0028] In an alternative embodiment, the non-grounded pins include a plurality of pins.

[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 electromagnetic shielding layer, and the electromagnetic shielding wire, 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 lead frame is a leadless quad flat package lead frame.

[0034] In an optional embodiment, the electromagnetic shielding layer is a rectangular annular shielding ring adapted to the leadless quad flat package lead frame.

[0035] 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.

[0036] 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.

[0037] In an optional embodiment, the chip structure is flip-chip disposed on the upper surface of the ungrounded pins and grounded pins of the lead frame.

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

[0039] By forming a first stepped groove on the molding compound, and then forming an electromagnetic shielding layer on top of this groove, and electrically connecting the electromagnetic shielding layer and the grounding pin of the leadframe via a grounding wire, the electromagnetic shielding wires can be sequentially connected to the grounding pin of the leadframe via the electromagnetic shielding layer and the electromagnetic shielding wires (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 leadframe package structure via wire bonding (electromagnetic shielding wires), and the electromagnetic shielding wires do not need to be directly grounded, significantly reducing the difficulty of wire bonding. Furthermore, by forming a continuous annular electromagnetic shielding layer around the chip structure, continuous electromagnetic shielding is achieved on the outer periphery of the chip structure. Combined with the electromagnetic shielding wires above the chip structure, electromagnetic shielding can be achieved on all five sides of the chip structure, resulting in a superior electromagnetic shielding effect for the package structure. Attached Figure Description

[0040] To more clearly illustrate the technical solutions of the embodiments of this utility model, 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 this utility model 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.

[0041] Figure 1 This is a top view of an embodiment of the electromagnetic shielding encapsulation structure of this application;

[0042] Figure 2 This is a schematic diagram of the electromagnetic shielding encapsulation structure along A1-A2 according to an embodiment of this application;

[0043] 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 ;

[0044] 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 ;

[0045] Figure 5 for Figure 4 Corresponding top view structural diagram (and Figure 4 for Figure 5 (Cross-section view along B1-B2)

[0046] 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 ;

[0047] 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)

[0048] 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 ;

[0049] 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 ;

[0050] 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 ;

[0051] 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 ;

[0052] Figure 12 This is a top view of another embodiment of the electromagnetic shielding encapsulation structure of this application;

[0053] Figure 13This is a schematic diagram of the process for forming an electromagnetic shielding encapsulation structure in one embodiment of this application.

[0054] The labels for the attached figures are as follows:

[0055] 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. First groove; 4. Electromagnetic shielding layer; 5. Electromagnetic shielding wire; 6. Grounding wire; 7. Adhesive layer; 8. Bonding wire; 100. Frame unit. Detailed Implementation

[0056] 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.

[0057] 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.

[0058] 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.

[0059] 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.

[0060] 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.

[0061] 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).

[0062] This application provides an electromagnetic shielding packaging structure, in conjunction with reference to... Figures 1-13 ,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 8This 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 top view of another embodiment of the electromagnetic shielding encapsulation structure of this application; Figure 13 This is a schematic diagram illustrating the process of forming an electromagnetic shielding packaging structure in one embodiment of this application; the electromagnetic shielding packaging structure includes:

[0063] 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.

[0064] Chip structure 2 is disposed on the upper surface of base island 11;

[0065] The molding layer 3 is located on the upper surface of the lead frame 1, covers the chip structure 2, and fills the space between the base island 11 and the pins, and between the pins. The molding layer 3 has a first stepped groove 31 on the edge of the surface away from the lead frame 1. The bottom surface of the first stepped groove 31 is a certain distance from the pins of the lead frame 1.

[0066] Electromagnetic shielding layer 4 is located on the surface of the first step groove 31;

[0067] 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 electromagnetic shielding layer 4 on the opposite side of the chip structure 2.

[0068] Grounding wire 6, with its two ends electrically connected to at least one grounding pin 12 of electromagnetic shielding layer 4 and lead frame 1, respectively.

[0069] 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.

[0070] This application forms a first stepped groove 31 on the molding layer 3, and an electromagnetic shielding layer 4 on the first stepped groove 31. The electromagnetic shielding layer 4 and the grounding pin 12 of the lead frame 1 are electrically connected via a grounding wire 6. This allows the electromagnetic shielding wire 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, achieving complete grounding. This results in electromagnetic shielding on five sides of the chip structure 2. In other words, this structural design allows the electromagnetic shielding structure to be formed in the lead frame package structure via wire bonding (electromagnetic shielding wire 5).

[0071] In one embodiment, the first step groove 31 is an annular groove arranged circumferentially around the chip structure 2;

[0072] The electromagnetic shielding layer 4 is a continuous annular shielding ring arranged in a circumferential direction around the chip structure 2.

[0073] By setting a continuous annular electromagnetic shielding layer 4 around the chip structure 2, continuous electromagnetic shielding is achieved on the outer periphery of the chip structure 2, thereby giving the packaging structure a better electromagnetic shielding effect.

[0074] In another embodiment, the first step groove 31 includes a plurality of first step grooves 31 arranged circumferentially around the chip structure 2;

[0075] The electromagnetic shielding layer 4 has multiple pieces, and the multiple electromagnetic shielding layers 4 are correspondingly arranged with multiple first step grooves 31.

[0076] Please refer to Figure 12 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.

[0077] 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.

[0078] In another embodiment, two electromagnetic shielding layers 4 may be formed on two sides of the chip structure 2, and the two electromagnetic shielding layers 4 may be electrically connected by an electromagnetic shielding line 5. At least one electromagnetic shielding layer 4 may be electrically connected to the grounding pin 12 of the lead frame 1 by a grounding line 6.

[0079] In one embodiment, the electromagnetic shielding 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.

[0080] In another embodiment, the electromagnetic shielding layer 4 is located on the bottom surface of the first stepped groove 31 and all the sides of the first stepped groove 31.

[0081] 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.

[0082] In one embodiment, the electromagnetic shielding wire 5 is in contact with the side of the electromagnetic shielding layer 4.

[0083] In one embodiment, the horizontal plane containing the bottom surface of the first stepped groove 31 is at least lower than the horizontal plane containing the upper surface of the chip structure 2 on the side away from the lead frame 1. This arrangement facilitates the formation of electromagnetic shielding on the outer side of the chip structure 2.

[0084] In one embodiment, the horizontal plane of the bottom surface of the first stepped groove 31 is lower than or coincides with the horizontal plane of the lower surface of the chip structure 2 on the side near the lead frame 1. This arrangement facilitates the formation of complete electromagnetic shielding of the chip structure 2 on its side.

[0085] In one embodiment, a plastic sealing layer 3 of a certain thickness is spaced between the bottom surface of the first step groove 31 and the upper surface of the lead frame 1.

[0086] In one embodiment, a first stepped groove 31 is located above the ungrounded pin 13 and the grounded pin 12, and a plastic seal layer is provided between the bottom surface of the first stepped groove 31 and the upper surface of the ungrounded pin 13 and the grounded pin 12.

[0087] In one embodiment, it also includes bonding wires 8, which are located within the molding compound 3;

[0088] The two ends of the bonding wire 8 are electrically connected to the ungrounded pin 13 of the chip structure 2 and the lead frame 1, respectively.

[0089] 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.

[0090] In one embodiment, the first stepped groove 31 is located above the ungrounded pin 13 and the grounded pin 12.

[0091] The width of the first step groove is less than the length of the tube pin, where the length of the tube pin refers to the distance from the end of the tube pin closest to the base island 11 to the end furthest from the base island 11.

[0092] In another embodiment, the chip structure 2 is disposed on the upper surface of the non-grounded pin 13 and the grounded pin 12 of the lead frame by flip-chip solder balls, in which case there is no need to form bonding wires.

[0093] In one embodiment, the non-grounded pin 13 includes a plurality of non-grounded pins 13 and grounded pins 12, which are spaced apart on the outer periphery of the base island 11 of the lead frame 1.

[0094] In one embodiment, the two ends of the grounding wire 6 are in contact with the side of the electromagnetic shielding layer 4 and the upper surface of the grounding pin 12, respectively.

[0095] In one embodiment, the electromagnetic shielding wire 5 includes multiple single wires, the two ends of which are electrically connected to the electromagnetic shielding layer 4. The electromagnetic shielding wire 5, the electromagnetic shielding layer 4, the grounding wire 6, and the grounding pin 12 are grounded.

[0096] In one embodiment, multiple single-wire bodies are arranged in a grid pattern.

[0097] In another specific embodiment, multiple single-line bodies are arranged in a parallel line structure.

[0098] In one embodiment, multiple single wires may or may not be in contact at the locations where they form cross nodes.

[0099] In one embodiment, the lead frame 1 is a leadless quad flat package lead frame (QFN lead frame).

[0100] In another embodiment, the lead frame 1 may also be a lead frame with a single-sided lead or a lead frame with a double-sided lead.

[0101] In one embodiment, the electromagnetic shielding layer 4 is a rectangular annular shielding ring adapted to the leadless quad flat package lead frame 1.

[0102] 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.

[0103] Please refer to Figures 2-13 This application also provides a method for preparing an electromagnetic shielding packaging structure, 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 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.

[0105] 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.

[0106] S300. Please refer to... Figure 6 and Figure 7 Electromagnetic shielding wire 5 is formed by bonding wires. Electromagnetic shielding wire 5 is laid across the chip structure 2 on the side away from the lead frame 1. The two ends of electromagnetic shielding wire 5 are respectively located on the upper surface of the connecting rib 14 of the lead frame 1 on opposite sides of the chip.

[0107] In one embodiment, when the chip structure 2 is disposed on the surface of the base island 11 by bonding wire 8, the bonding wire 8 is further formed before the electromagnetic shielding wire 5 is formed. The two ends of the bonding wire 8 are electrically connected to the pads of the chip structure 2 and the non-grounded pins 13 of the lead frame 1, respectively.

[0108] In another embodiment, the chip structure 2 is disposed on the upper surface of the non-grounded pin 13 and the grounded pin 12 of the lead frame 1 by flip-chip solder balls, in which case the bonding wire 8 is not required.

[0109] S400. Please refer to... Figure 8 A molding layer 3 is formed, which is located on the upper surface of the lead frame 1 and covers the chip structure 2, electromagnetic shielding line 5, and grounding line 6, and fills the space between the base island 11 and the pins, and between the pins.

[0110] In one embodiment, when the chip structure 2 is connected to the pins of the lead frame 1 via the bonding wire 8, the bonding wire 8 is located within the molding compound 3.

[0111] S500. Please refer to... Figure 9 A first groove 32 (front cut) is formed by a single cut. The first groove 32 is located on the side of the plastic encapsulation layer 3 away from the lead frame 1. The sidewall of the first groove 32 exposes the electromagnetic shielding wire 5 and / or the grounding wire 6. The width of the single cut is greater than the width of the connecting rib 14.

[0112] In one embodiment, the first groove 32 is formed by photolithography.

[0113] In another embodiment, the first groove 32 can also be formed by a single cut using a cutting tool.

[0114] S600. Please refer to... Figure 10 An electromagnetic shielding layer 4 is formed on the inner wall of the first groove 32 by a sputtering process. The electromagnetic shielding layer 4 is electrically connected to the electromagnetic shielding line 5 and / or the grounding line 6.

[0115] In one embodiment, when the electromagnetic shielding layer 4 is formed on the inner wall of the first groove 32, the electromagnetic shielding layer 4 does not completely fill the first groove 32.

[0116] In another embodiment, when an electromagnetic shielding layer 4 is formed on the inner wall of the first groove 32, the electromagnetic shielding layer 4 fills the first groove 32 completely.

[0117] S700. Please refer to... Figure 11 A secondary cut is made at the bottom of the first groove 32 to cut off the connecting rib 14 and / or part of the pins near the connecting rib, and to cut off the corresponding plastic encapsulation layer 3 and the electromagnetic shielding line 5 and / or grounding line 6 remaining in the plastic encapsulation layer 3 to form a single electromagnetic shielding encapsulation structure. The cutting width of the secondary cut is greater than the width of the connecting rib 14 and less than the cutting width of the first cut, so that the first groove 32 forms the first stepped groove 31.

[0118] 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.

[0119] 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 shielded package structure, 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 compound is located on the upper surface of the lead frame, covering the chip structure and filling the space between the base island and the pins, and between the pins. The molding compound has a first stepped groove on the edge of the surface away from the lead frame, and the bottom surface of the first stepped groove is a certain distance from the pins of the lead frame. An electromagnetic shielding layer, wherein the electromagnetic shielding layer is located on the surface of the groove of the first step; An electromagnetic shielding wire is located within the molding compound and spans across the chip structure on the side away from the lead frame. The ends of the electromagnetic shielding wire are electrically connected to the opposite electromagnetic shielding layer. A grounding wire, the two ends of which are electrically connected to the grounding pins of the electromagnetic shielding layer and the lead frame, respectively.

2. An electromagnetic shielding package structure as claimed in claim 1, wherein, The first step groove is an annular groove arranged in a circumferential direction around the chip structure.

3. An electromagnetic shielding package structure as claimed in claim 2, wherein, The electromagnetic shielding layer is a continuous annular shielding ring arranged in a circumferential direction around the chip structure.

4. The electromagnetic shielding packaging structure 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 electromagnetic shielding layer comprises multiple blocks, and each block of the electromagnetic shielding layer is correspondingly arranged with multiple first step grooves.

5. The electromagnetic shielding packaging structure as described in claim 1, characterized in that, The electromagnetic shielding 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.

6. The electromagnetic shielding packaging structure as described in claim 1, characterized in that, The horizontal plane at which the bottom surface of the first 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.

7. The electromagnetic shielding packaging structure as described in claim 1, characterized in that, A plastic sealing layer of a certain thickness is spaced between the bottom surface of the first step groove and the upper surface of the lead frame.

8. The electromagnetic shielding packaging structure as described in claim 7, characterized in that, The first step groove is located above the ungrounded pin and the grounded pin, and there is a plastic seal between the bottom surface of the first step groove and the upper surface of the ungrounded pin and the grounded pin.

9. 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 electrically connected to the pads of the chip structure and the pins of the lead frame, respectively.

10. 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 ungrounded pins and grounded pins of the lead frame.

11. The electromagnetic shielding packaging structure as described in claim 1, characterized in that, The first stepped groove is located above the ungrounded pin and the grounded pin; The width of the first step groove is less than the length of the tube foot.

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

13. The electromagnetic shielding packaging structure as described in claim 12, 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.

14. 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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