Electromagnetic shielding packaging method and electromagnetic shielding packaging structure

Abstract

The present application discloses an electromagnetic shielding packaging method and an electromagnetic shielding packaging structure. The electromagnetic shielding packaging method includes: mounting at least two chips on a first surface of a substrate; forming a plastic package body on the substrate to cover the chips; providing a groove in the plastic package body and the substrate, the groove extending along the thickness of the plastic package body and extending to the ground layer of the substrate; the groove being located between two adjacent chips; and covering the outer surface of the plastic package body with a conductive polymer film by hot pressing, and filling the groove with the conductive polymer film.

Description

Technical Field

[0001] The present application relates to the field of semiconductor technology, and more specifically, to an electromagnetic shielding packaging method and an electromagnetic shielding packaging structure. Background Art

[0002] In the field of semiconductor technology, there are many integrated circuit chips (ICs) that are sensitive to electromagnetic interference, such as radio frequency chips, especially high-frequency radio frequency chips. These chips must be electromagnetically shielded before operation.

[0003] In the prior art, electromagnetic shielding of a chip is usually performed by placing a metal shell around the chip package, or forming a metal film outside the chip package by magnetron sputtering.

[0004] The metal casing increases the size of the chip package. During magnetron sputtering, over-plating can easily cause short circuits. Furthermore, the metal layer formed on the chip package using magnetron sputtering has poor adhesion to the package, making it prone to peeling off during use. Summary of the Invention

[0005] One object of the present application is to provide a technical solution for an electromagnetic shielding packaging method and an electromagnetic shielding packaging structure to solve at least one technical problem raised by the background art.

[0006] According to a first aspect of the present application, an electromagnetic shielding packaging method is provided. The electromagnetic shielding packaging method comprises:

[0007] Mounting at least two chips on the first surface of the substrate;

[0008] forming a plastic package covering the chip on the substrate;

[0009] A groove is formed on the plastic package body and the substrate, wherein the groove extends along the thickness direction of the plastic package body and extends to the ground layer of the substrate; the groove is located between two adjacent chips;

[0010] The outer surface of the plastic package is covered with a conductive polymer film by hot pressing, and the groove is filled with the conductive polymer film.

[0011] Optionally, the step of forming grooves on the plastic package body and the substrate includes: forming grooves on the plastic package body and the substrate by laser grooving, so that a ground layer in the substrate is exposed.

[0012] Optionally, the outer surface of the plastic package is covered with a conductive polymer film by hot pressing, and the groove is filled with a conductive polymer film, including:

[0013] A conductive polymer film is provided on the cavity surface of the first mold of the hot pressing mold;

[0014] The first mold cover of the hot pressing mold is arranged on the plastic sealing body so that the plastic sealing body is located in the mold cavity;

[0015] The first mold and the second mold of the hot pressing mold are closed and heated and pressurized so that the outer surface of the plastic package is covered with the conductive polymer film and the groove is filled with the conductive polymer film.

[0016] Optionally, the step of providing a conductive polymer film on the cavity surface of the first mold of the hot pressing mold includes: adsorbing the conductive polymer film on the cavity surface of the first mold by vacuum adsorption.

[0017] Optionally, the heating temperature ranges from 100°C to 300°C.

[0018] Optionally, the conductive polymer film includes: a thermosetting matrix and a conductive filler filled in the thermosetting matrix.

[0019] Optionally, the thermosetting matrix and the plastic package body are connected by chemical bonds during the hot pressing process.

[0020] Optionally, the conductive filler includes metal nanowires and metal nanoparticles.

[0021] Optionally, in the conductive polymer film, the mass ratio of the conductive filler is in the range of 40% to 80%.

[0022] Optionally, the conductive polymer film has a thickness ranging from 10 μm to 40 μm.

[0023] According to a second aspect of an embodiment of the present application, an electromagnetic shielding packaging structure is provided. The electromagnetic shielding packaging structure includes:

[0024] a substrate, on which at least two chips are mounted;

[0025] A plastic package body, the plastic package body covering the chip; a groove extending to the ground layer of the substrate is formed on the plastic package body along the thickness direction of the plastic package body; the groove is located between adjacent chips;

[0026] The conductive polymer film is formed by heat pressing so that the conductive polymer film covers the outer surface of the plastic package and fills the groove.

[0027] Optionally, the conductive polymer film includes: a thermosetting matrix and a conductive filler filled in the thermosetting matrix.

[0028] According to one embodiment of the present application, a method for electromagnetic shielding packaging is provided. In this embodiment, a groove is formed along the thickness of a plastic package, extending to a ground layer of a substrate. A conductive polymer film is coated on the outer surface of the plastic package by heat pressing, and the groove is filled with the conductive polymer film. The conductive polymer film is connected to the ground layer to form a grounding effect, thereby achieving electromagnetic shielding for the chip.

[0029] In the embodiments of the present application, the grooves are located between two adjacent chips, and each groove is completely filled with a conductive polymer film that has been melted by heat pressing, so that each chip is wrapped in the conductive polymer film and each chip has an electromagnetic shielding effect. The electromagnetic shielding packaging method provided in the embodiments of the present application can simultaneously and individually shield each chip in multiple chips.

[0030] In the embodiments of the present application, a conductive polymer film is formed on the chip's plastic package by hot pressing. Compared to placing a metal shell outside the plastic package, this application reduces the volume of the chip packaging structure to a certain extent. Compared to forming a metal coating by magnetron sputtering, the conductive polymer film in this application can be evenly coated on the surface of the plastic package after hot pressing and melting to form an electromagnetic shielding layer, avoiding the chip short circuit caused by overflow plating during the magnetron sputtering process.

[0031] In an embodiment of the present application, a conductive polymer film is used to form an electromagnetic shielding layer on the plastic packaging surface of the chip by hot pressing, and interface bonding is achieved through chemical bonds, thereby improving the bonding strength between the electromagnetic shielding layer and the plastic packaging body and avoiding the problem of easy falling off of the electromagnetic shielding layer.

[0032] Other features and advantages of the present application will become apparent from the following detailed description of exemplary embodiments of the present application with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the application and, together with the description, serve to explain the principles of the application.

[0034] Figure 1 Shown is a schematic structural diagram of mounting a chip on the surface of a substrate in an embodiment of the present application.

[0035] Figure 2 The figure shows a schematic structural diagram of a groove formed on a plastic package body in an embodiment of the present application.

[0036] Figure 3 Shown is a schematic diagram of placing a conductive polymer film in a hot pressing mold in an embodiment of the present application.

[0037] Figure 4 The figure shows a schematic diagram of the structure of the conductive polymer film wrapped chip in an embodiment of the present application.

[0038] Figure 5 Shown is a flow chart of the electromagnetic shielding packaging method in an embodiment of the present application.

[0039] Figure 6 The figure shows a schematic structural diagram of a conductive network of conductive particles in a conductive polymer film according to an embodiment of the present application.

[0040] Figure 7 Shown is a schematic diagram of the reaction process between the conductive polymer film and the plastic package.

[0041] Description of reference numerals:

[0042] 1. Substrate; 11. Ground layer;

[0043] 2. Chip; 21. First chip; 22. Second chip;

[0044] 3. Plastic package; 4. Groove; 5. Conductive polymer film; 51. Thermosetting matrix; 52. Metal nanoparticles; 53. Metal nanowires; 6. Hot pressing mold; 61. First mold; 62. Second mold. DETAILED DESCRIPTION

[0045] Various exemplary embodiments of the present application will now be described in detail with reference to the accompanying drawings. It should be noted that unless otherwise specifically stated, the relative arrangements of components and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present application.

[0046] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the present disclosure, its application, or uses.

[0047] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered part of the specification.

[0048] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not limiting. Therefore, other examples of the exemplary embodiments may have different values.

[0049] It should be noted that like reference numerals and letters refer to like items in the following figures, and therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0050] According to the first aspect of the embodiment of the present application, an electromagnetic shielding packaging method is provided. Figure 5 As shown, the electromagnetic shielding packaging method includes:

[0051] S101: Mounting at least two chips 2 on the first surface of the substrate 1;

[0052] S102: forming a plastic package 3 covering the chip 2 on the substrate 1;

[0053] S103: forming a groove 4 on the plastic package 3 and the substrate 1, wherein the groove 4 extends along the thickness direction of the plastic package 3 and extends to the ground layer 11 of the substrate 1; the groove 4 is located between two adjacent chips 2;

[0054] S104: The outer surface of the plastic package body 3 is covered with a conductive polymer film 5 by hot pressing, and the groove 4 is filled with the conductive polymer film 5.

[0055] In step S101, refer to Figure 1 As shown, a substrate 1 and chips 2 are provided. A chip 2 mounting area is provided on a first surface of the substrate 1. Multiple chips 2 are mounted one-to-one in the chip 2 mounting area using a surface mounting process.

[0056] In step S102, refer to Figure 1 As shown, a plastic encapsulation process is used to form a plastic encapsulation body 3 on a substrate 1. The plastic encapsulation body 3 encapsulates the chip 2, thereby protecting the chip 2. In a specific embodiment, the plastic encapsulation body 3 is formed of epoxy resin. In an optional embodiment, thermally conductive particles are added to the plastic encapsulation body 3 to improve the thermal conductivity of the plastic encapsulation body 3.

[0057] In step S103, refer to Figure 2 As shown, grooves 4 are formed in the plastic encapsulation body 3 and the substrate 1, extending along the thickness direction of the plastic encapsulation body 3. That is, grooves 4 are formed in the plastic encapsulation body 3 and grooves 4 are also formed in the substrate 1. Therefore, the grooves 4 formed in the plastic encapsulation body 3 penetrate the plastic encapsulation body 3. The grooves 4 formed in the substrate 1 do not penetrate the substrate 1. The grooves 4 formed in the substrate 1 extend to the ground layer 11 of the substrate 1, exposing the ground layer of the substrate 1 and not penetrating the ground layer 11. The ground layer 11 can be a grounding copper layer.

[0058] Reference Figure 2 As shown, a groove 4 is formed on the plastic package 3 and the substrate 1 between two adjacent chips 2. In one embodiment, a plurality of chips 2 are arranged on the substrate 1, and the plurality of chips 2 are arranged in a straight line. The plurality of chips 2 include a first chip 21, a second chip 22, and a third chip. The first chip 21 is located at the edge area of ​​the substrate 1, the second chip 22 is located in the inner area of ​​the substrate 1, and the third chip is located at the edge area of ​​the substrate 1. A groove 4 is formed between the first chip 21 and the second chip 22, and a groove 4 is formed between the second chip 22 and the third chip.

[0059] In step S104, refer to Figure 3 and Figure 4 As shown, the outer surface of the plastic package body 3 is covered with a conductive polymer film 5 by hot pressing, and the groove 4 is filled with the conductive polymer film 5.

[0060] Specifically, a conductive polymer film 5 is formed on the outer surface (side and top surfaces) of the plastic package 3 by heat pressing. The conductive polymer film 5 serves as an electromagnetic shielding layer. An electromagnetic shielding layer is formed on the inner surface of the groove 4 (the two opposing surfaces of the groove 4 and the bottom surface connected to the two surfaces, where the bottom surface serves as the ground layer 11).

[0061] In the electromagnetic shielding packaging method provided in the embodiment of the present application, the conductive polymer film 5 can be evenly covered on the surface of the plastic package 3 after hot pressing and melting to form an electromagnetic shielding layer, and the conductive polymer film 5 can be filled in the groove 4 after hot pressing and melting to form an electromagnetic shielding layer. The electromagnetic shielding layer is connected to the grounding layer 11 to form a grounding effect, and the chip 2 has an electromagnetic shielding effect.

[0062] In the embodiment of the present application, the grooves 4 are located between two adjacent chips 2. The surface of each groove 4 is completely filled with a conductive polymer film 5 that has been melted by heat pressing, so that each chip 2 is wrapped by the conductive polymer film 5, and each chip 2 has an electromagnetic shielding effect. The electromagnetic shielding packaging method provided in the embodiment of the present application can simultaneously and individually shield each chip 2 in a plurality of chips 2.

[0063] In the embodiment of the present application, a conductive polymer film 5 is formed on the chip's plastic package 3 by hot pressing. Compared to providing a metal shell outside the plastic package, the present application reduces the volume of the chip packaging structure to a certain extent. Compared to forming a metal coating by magnetron sputtering, the conductive polymer film 5 of the present application can be evenly coated on the surface of the plastic package 3 after hot pressing and melting to form an electromagnetic shielding layer, thus avoiding the chip short circuit caused by overflow plating during the magnetron sputtering process.

[0064] In an embodiment of the present application, a conductive polymer film 5 is used to form an electromagnetic shielding layer on the surface of the plastic package 3 of the chip by hot pressing, and interface bonding is achieved through chemical bonds, thereby improving the bonding strength between the electromagnetic shielding layer and the plastic package and avoiding the problem of easy falling off of the electromagnetic shielding layer.

[0065] In one embodiment, referring to Figure 2 As shown, the step of forming the groove 4 on the plastic package 3 and the substrate 1 includes: forming the groove 4 on the plastic package 3 and the substrate 1 by laser grooving, so that the ground layer 11 on the substrate 1 is exposed.

[0066] Specifically, laser is also known as laser. The principle of laser processing is that a laser beam with a high energy density is irradiated on the surface of the material being processed. The surface of the material absorbs the laser energy, causing the temperature to rise, resulting in melting, ablation, and evaporation, thereby achieving the purpose of removing part of the processed material.

[0067] In this embodiment, a groove 4 is formed in the plastic package 3 using a predetermined laser energy. For example, by controlling the laser energy, the depth and width of the groove 4 are strictly controlled to prevent the groove 4 from being too wide, thereby affecting the normal use of the chip 2, and to prevent the groove 4 from being too deep, thereby damaging the structure of the ground layer 11 and preventing the conductive polymer film from being grounded.

[0068] In one embodiment, referring to Figure 3 and Figure 4 As shown, the outer surface of the plastic package 3 is covered with a conductive polymer film 5 by hot pressing, and the groove 4 is filled with the conductive polymer film 5, including:

[0069] A conductive polymer film 5 is provided on the cavity surface of the first mold 61 of the hot pressing mold 6;

[0070] The first mold 61 of the hot pressing mold 6 is covered on the plastic package body 3 so that the plastic package body 3 is located in the mold cavity;

[0071] The first mold 61 and the second mold 62 of the hot pressing mold 6 are closed and heated, so that the outer surface of the plastic package body 3 is covered with the conductive polymer film 5 and the groove 4 is filled with the conductive polymer film 5 .

[0072] In this embodiment, the conductive polymer film 5 is hot-pressed by a hot-pressing mold 6 so that the hot-pressed and melted conductive polymer film can cover the surface of the plastic package 3 to form an electromagnetic shielding layer, and the hot-pressed and melted conductive polymer film can fill the groove 4 to form an electromagnetic shielding layer.

[0073] In this embodiment, the first mold 61 of the hot pressing mold 6 is the upper mold of the hot pressing mold 6 , and the second mold 62 of the hot pressing mold 6 is the lower mold of the hot pressing mold 6 .

[0074] A conductive polymer film 5 is placed on the cavity surface of the upper mold of the hot pressing mold 6. For example, the conductive polymer film 5 is simply placed on, adsorbed on, or coated on the cavity of the upper mold. While the conductive polymer film 5 is placed on the cavity surface of the upper mold, the cavity still has space to accommodate the plastic package 3.

[0075] During operation, the upper mold of the hot pressing module is placed on the plastic package body 3 , and the plastic package body 3 is accommodated in the mold cavity of the upper mold. That is, the conductive polymer film 5 is arranged around the outer periphery of the plastic package body 3 .

[0076] The upper mold and the lower mold of the hot pressing mold 6 are combined, and the conductive polymer film surrounding the outer periphery of the plastic package 3 is melted at high temperature. The molten conductive polymer film 5 fills the groove 4, and at the same time, the molten conductive polymer film 5 covers the outer surface of the plastic package 3; under the action of hot pressing, the molten conductive polymer film 5 solidifies and hardens to form a film layer, that is, the conductive polymer film 5 is covered in the groove 4 and the outer surface of the plastic package 3. The conductive polymer film 5 is an electromagnetic shielding layer, which makes the chip 2 have an electromagnetic shielding effect.

[0077] In this embodiment, the upper mold and the lower mold of the hot pressing mold 6 are closed together, including: the upper mold cover of the hot pressing mold 6 is set on the plastic packaging body 3, the lower mold is set on the second surface of the substrate 1 (the second surface is the surface opposite to the first surface of the substrate 1), and then the upper mold and the lower mold are closed together.

[0078] In this embodiment, the conductive polymer film 5 is placed in a hot pressing mold 6. Under a certain temperature and pressure, the conductive polymer film 5 is in a molten state. The molten conductive polymer film 5 flows onto the outer surface of the plastic package 3 and into the groove 4. Under the action of hot pressing, the molten conductive polymer film 5 is formed into a film layer. The film-layer conductive polymer film 5 is combined with the surface of the plastic package 3 (including the outer surface of the plastic package 3 and the surface of the groove 4) to form a conductive polymer film 5 on the surface of the plastic package 3. The conductive polymer film 5 is an electromagnetic shielding layer, which makes the chip 2 have an electromagnetic shielding effect.

[0079] In one embodiment, referring to Figure 3 As shown, the step of providing a conductive polymer film 5 on the cavity surface of the first mold 61 of the hot pressing mold 6 includes:

[0080] The conductive polymer film 5 is adsorbed on the cavity surface of the first mold 61 by vacuum adsorption.

[0081] In this embodiment, a vacuum adsorption device is provided on the first mold 61, and the conductive polymer film 5 is adsorbed on the cavity surface of the upper mold by the vacuum adsorption device. For example, the vacuum adsorption device can be a vacuum suction cup or other vacuum adsorption devices.

[0082] In this embodiment, the method of disposing the conductive polymer film 5 on the surface of the cavity film is simple and easy to operate.

[0083] In one embodiment, the heating temperature ranges from 100°C to 300°C.

[0084] In this embodiment, the heating temperature during the hot pressing process is limited to this range, and the conductive polymer film 5 has good fluidity and filling properties. In addition, the heating temperature is limited to this range, and the conductive polymer film 5 and the plastic package 3 undergo a chemical reaction, so that the conductive polymer film 5 covers the surface of the plastic package 3, and the conductive polymer film 5 and the plastic package 3 have good bonding strength. Preferably, the heating temperature range is 150°C-200°C

[0085] In one embodiment, referring to Figure 6 As shown, the conductive polymer film 5 includes a thermosetting matrix 51 and a conductive filler filled in the thermosetting matrix 51 .

[0086] Furthermore, the thermosetting matrix 51 and the plastic package body 3 are connected by chemical bonds during the hot pressing process.

[0087] In this embodiment, the substrate of the conductive polymer film 5 is a thermosetting substrate 51 (thermosetting refers to the property that it cannot soften or be repeatedly molded when heated, nor can it dissolve in solvents. Bulk polymers have this property). When the conductive polymer film 5 is coated on the surface of the plastic package 3, the conductive polymer film 5 will not flow or soften even when the temperature rises during use of the chip 2, thereby improving the reliability of the conductive polymer film 5. For example, it can be a thermosetting resin film.

[0088] In this embodiment, the substrate of the conductive polymer film 5 is a thermosetting substrate 51. The thermosetting substrate 51 is selected from the curing agent system of the plastic package 3 to enhance the bonding strength between the conductive polymer film 5 and the surface of the plastic package 3. That is, the conductive polymer film 5 and the plastic package 3 are connected by chemical bonds during the hot pressing process.

[0089] For example, in a specific embodiment, the thermosetting matrix 51 is formed of epoxy resin, and the thermosetting matrix 51 also includes a curing agent. The plastic package body 3 is formed of epoxy resin.

[0090] The conductive polymer film 5 and the plastic package body 3 are bonded together by forming chemical bonds during the hot pressing process, which greatly enhances the bonding force between the conductive polymer film 5 and the surface of the plastic package body 3 .

[0091] This reaction involves a curing reaction between the -OH group at one end of the curing agent molecule in the conductive polymer film 5 and the uncured epoxy molecules on the surface of the plastic package 3 under heat and pressure. Subsequently, the -OH group at the other end of the curing agent reacts with the epoxy molecules in the conductive polymer film 5. This chemical bond forms an interface between the conductive polymer film 5 and the plastic package 3, thereby enhancing interfacial bonding. This reaction process is shown in Figure 7.

[0092] In this embodiment, the bonding force between the conductive polymer film 5 and the plastic package body 3 is improved, thereby preventing the conductive polymer film 5 from falling off from the plastic package body 3 during use.

[0093] In one embodiment, referring to Figure 6 As shown, the conductive filler includes metal nanowires 53 and metal nanoparticles 52 .

[0094] In this embodiment, the conductive polymer film 5 is a thermosetting film containing a conductive filler. The conductive filler is a mixed filler of metal nanoparticles 52 and metal nanowires 53. For example, the metal nanoparticles 52 and the metal nanowires 53 are made of the same metal. By utilizing the low-temperature sintering effect of the metal nanoparticles 52 (the low-temperature sintering effect, i.e., the nano-sized metal material has a significantly lower melting point (100-300°C), at this temperature, the metal nanoparticles 52 and the metal nanowires 53 are in contact with each other (i.e., Figure 6 The area enclosed by the rectangular frame shown is the contact point) and is melted and sintered together). At the processing temperature (100-300°C, preferably 150°C-200°C), the metal nanowires 53 and nanoparticles will build a three-dimensional conductive network through low-temperature sintering, so that the conductive polymer film 5 has conductive properties.

[0095] In one embodiment, in the conductive polymer film 5 , the mass ratio of the conductive filler is in the range of 40% to 80%.

[0096] In this embodiment, compared to the conductive filler consisting only of metal nanoparticles 52 , the conductive filler in this embodiment comprises metal nanowires 53 and metal nanoparticles 52 , thereby reducing the range of the conductive filler mass ratio.

[0097] Specifically, the conductive filler comprises metal nanowires 53 and metal nanoparticles 52, and the weight ratio of the conductive filler to prepare the conductive polymer film 5 is in the range of 40% to 80%. If the conductive filler comprises only metal nanoparticles 52, and a conductive polymer having the same conductivity as the above-mentioned conductive polymer (with the same thermosetting matrix 51) is prepared, the weight ratio of the metal nanoparticles 52 must be at least greater than 80%.

[0098] For example, in the conductive polymer film 5 , the mass ratio of the conductive filler is 40%, the mass ratio of the thermosetting matrix 51 is 50%, and the mass ratio of other filler components is 10%.

[0099] For example, in the conductive polymer film 5 , the mass ratio of the conductive filler is 75%, the mass ratio of the thermosetting matrix 51 is 20%, and the mass ratio of other filler components is 5%.

[0100] For example, in the conductive polymer film 5 , the mass ratio of the conductive filler is 55%, the mass ratio of the thermosetting matrix 51 is 35%, and the mass ratio of other filler components is 10%.

[0101] For example, in the conductive polymer film 5 , the mass ratio of the conductive filler is 60%, the mass ratio of the thermosetting matrix 51 is 30%, and the mass ratio of other filler components is 10%.

[0102] In one embodiment, the thickness of the conductive polymer film 5 is in the range of 10 μm to 40 μm.

[0103] In this embodiment, the thickness of the conductive polymer film 5 is limited, so that the package volume of the chip 2 is reduced while ensuring the electromagnetic shielding effect of the chip 2 .

[0104] According to a second aspect of an embodiment of the present application, an electromagnetic shielding packaging structure is provided. Referring to FIG4 , the electromagnetic shielding packaging structure includes:

[0105] A substrate 1, on which at least two chips 2 are mounted;

[0106] A plastic package 3 covering the chip 2; a groove 4 extending to the ground layer 11 of the substrate 1 is formed on the plastic package 3 along its thickness direction; the groove 4 is located between adjacent chips 2;

[0107] The conductive polymer film 5 is hot-pressed so that the molten conductive polymer film covers the outer surface of the plastic package 3 and fills the groove 4 to form an electromagnetic shielding layer.

[0108] In this embodiment, a conductive polymer film is formed on the chip's plastic package 3 by hot pressing. The conductive polymer film serves as an electromagnetic shielding film. Compared to placing a metal shell outside the plastic package 3, this application reduces the volume of the chip packaging structure to a certain extent. Compared to forming a metal coating by magnetron sputtering, the conductive polymer film 5 in this application can be evenly coated on the surface of the plastic package after hot pressing and melting to form an electromagnetic shielding layer, thus avoiding the chip short circuit caused by overflow plating during the magnetron sputtering process.

[0109] In an embodiment of the present application, a conductive polymer film is used to form an electromagnetic shielding layer on the plastic packaging surface of the chip by hot pressing, and interface bonding is achieved through chemical bonds, thereby improving the bonding strength between the electromagnetic shielding layer and the plastic packaging body and avoiding the problem of easy falling off of the electromagnetic shielding layer.

[0110] In one embodiment, the conductive polymer film 5 includes a thermosetting matrix 51 and a conductive filler filled in the thermosetting matrix 51 .

[0111] In this embodiment, the bonding force between the conductive polymer film 5 and the plastic package body 3 is improved, thereby preventing the conductive polymer film 5 from falling off from the plastic package body 3 during use.

[0112] The above embodiments focus on the differences between the various embodiments. As long as the different optimization features between the various embodiments are not contradictory, they can be combined to form a better embodiment. Considering the simplicity of the text, they will not be repeated here.

[0113] Although some specific embodiments of the present application have been described in detail by way of examples, it should be understood by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the present application. It should be understood by those skilled in the art that the above embodiments may be modified without departing from the scope and spirit of the present application. The scope of the present application is defined by the appended claims.

Claims

1. An electromagnetic shielding packaging method, characterized in that: include: Mounting at least two chips (2) on a first surface of a substrate (1); forming a plastic package (3) covering the chip (2) on the substrate (1); A groove (4) is provided on the plastic package (3) and the substrate (1), wherein the groove (4) extends along the thickness direction of the plastic package (3) and extends to the ground layer (11) of the substrate (1); the groove (4) is located between two adjacent chips (2); The outer surface of the plastic package (3) is covered with a conductive polymer film (5) by hot pressing, and the groove (4) is filled with the conductive polymer film (5); The outer surface of the plastic package (3) is covered with a conductive polymer film (5) by hot pressing, and the groove (4) is filled with the conductive polymer film (5), comprising: A conductive polymer film (5) is provided on the surface of the mold cavity of the first mold (61) of the hot pressing mold (6); the first mold (61) of the hot pressing mold (6) is covered on the plastic package (3), so that the plastic package (3) is located in the mold cavity; The first mold (61) and the second mold (62) of the hot pressing mold (6) are combined and hot pressing is performed, so that the molten conductive polymer film (5) fills the groove (4), and at the same time, the molten conductive polymer film (5) covers the outer surface of the plastic package (3) to coat the conductive polymer film (5) in the groove (4) and on the outer surface of the plastic package (3).

2. The electromagnetic shielding packaging method according to claim 1, characterized in that: The step of forming grooves (4) on the plastic package (3) and the substrate (1) comprises: forming grooves (4) on the plastic package (3) and the substrate (1) by laser grooving, so that the grounding layer (11) in the substrate (1) is exposed.

3. The electromagnetic shielding packaging method according to claim 1, characterized in that: The step of providing a conductive polymer film (5) on the cavity surface of a first mold (61) of a hot pressing mold (6) comprises: The conductive polymer film (5) is adsorbed on the cavity surface of the first mold (61) by vacuum adsorption.

4. The electromagnetic shielding packaging method according to claim 1, wherein: The heating temperature range is 100℃-300℃.

5. The electromagnetic shielding packaging method according to claim 1, wherein: The conductive polymer film (5) comprises a thermosetting matrix (51) and a conductive filler filled in the thermosetting matrix (51).

6. The electromagnetic shielding packaging method according to claim 5, characterized in that: The thermosetting matrix (51) and the plastic package (3) are connected by chemical bonds during the hot pressing process.

7. The electromagnetic shielding packaging method according to claim 5, characterized in that: The conductive filler includes metal nanowires (53) and metal nanoparticles (52).

8. The electromagnetic shielding packaging method according to claim 5, characterized in that: In the conductive polymer film (5), the mass ratio of the conductive filler is in the range of 40% to 80%.

9. The electromagnetic shielding packaging method according to claim 1, characterized in that: The thickness of the conductive polymer film (5) ranges from 10 μm to 40 μm.

10. An electromagnetic shielding packaging structure, characterized in that: include: A substrate (1), with at least two chips (2) mounted on the substrate (1); A plastic package (3), the plastic package (3) covering the chip (2); along the thickness direction of the plastic package (3), a groove (4) extending to the ground layer (11) of the substrate (1) is provided on the plastic package (3); the groove (4) is located between adjacent chips (2); A conductive polymer film (5) is applied by hot pressing so that the conductive polymer film (5) covers the outer surface of the plastic package (3) and fills the groove (4); The outer surface of the plastic package (3) is covered with a conductive polymer film (5) by hot pressing, and the groove (4) is filled with the conductive polymer film (5), comprising: A conductive polymer film (5) is provided on the surface of the mold cavity of the first mold (61) of the hot pressing mold (6); the first mold (61) of the hot pressing mold (6) is covered on the plastic package (3), so that the plastic package (3) is located in the mold cavity; The first mold (61) and the second mold (62) of the hot pressing mold (6) are combined and hot pressing is performed, so that the molten conductive polymer film (5) fills the groove (4), and at the same time, the molten conductive polymer film (5) covers the outer surface of the plastic package (3) to coat the conductive polymer film (5) in the groove (4) and on the outer surface of the plastic package (3).

11. The electromagnetic shielding packaging structure according to claim 10, characterized in that: The conductive polymer film (5) comprises a thermosetting matrix (51) and a conductive filler filled in the thermosetting matrix (51).

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