Chip package structure with electromagnetic shielding function, manufacturing method and packaging equipment

Abstract

The application provides a chip packaging structure with electromagnetic shielding function, a manufacturing method and a packaging device. The packaging structure comprises a carrier, at least one chip arranged on the carrier and a plastic encapsulation body covering the chip. A dense metal particle aggregation layer is formed on the surface area of the plastic encapsulation body. The manufacturing method comprises the following steps: adding metal particles into liquid injection plastic; providing a to-be-injected packaging structure; placing the to-be-injected packaging structure in a cavity of an injection mold; filling the cavity with the injection plastic; heating and pressurizing the injection plastic to change the injection plastic into liquid, or when the injection plastic is liquid at room temperature, opening an electrode embedded in the injection mold to form an electric field in the cavity, and under the action of the electric field, the metal particles are aggregated towards the surface area of the injection plastic; and solidifying the injection plastic to obtain an injected packaging structure. The metal particle aggregation layer formed directly in the injection process is used to replace the traditional metal shielding layer formed by plating on the outside of the packaging body, and the production process steps are simple, which is conducive to reducing the production cost.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of packaging technology, in particular to a chip packaging structure with electromagnetic shielding function, a manufacturing method and a packaging equipment. BACKGROUND

[0002] Various digital and high frequency electronic components emit a large amount of electromagnetic waves of different frequencies and wavelengths into space when working. Electromagnetic radiation and electromagnetic waves can seriously interfere with the performance of electronic components. With the development of electronic and communication technology, the demand for electromagnetic shielding devices in chip electronic packaging continues to grow, and the requirements for electromagnetic shielding are also becoming higher and higher.

[0003] At present, most chip packaging electromagnetic shielding structures are coated with a metal shielding layer on the surface of the plastic package or embedded with a metal plate in the plastic package. The process steps are complex, the process is long, and the processing cost is high. SUMMARY

[0004] The purpose of the present application is to provide a chip packaging structure with electromagnetic shielding function, a manufacturing method and a packaging equipment.

[0005] The present application provides a chip packaging structure with electromagnetic shielding function, comprising a carrier, at least one chip disposed on the carrier, and a plastic package covering the chip, wherein the surface layer region of the plastic package is aggregated with metal particles.

[0006] As a further improvement of the present application, the surface of the metal particles is coated with a layer of insulating material.

[0007] As a further improvement of the present application, the metal particles are doped sintered silver powder particles.

[0008] The present application also provides a manufacturing method of a chip packaging structure with electromagnetic shielding function, comprising the following steps:

[0009] Adding metal particles to the liquid injection plastic, and uniformly mixing the metal particles with the injection plastic;

[0010] Providing a to-be-injection-molded packaging structure, placing the to-be-injection-molded packaging structure in the cavity of the injection mold, and filling the injection plastic into the cavity;

[0011] Warming and pressurizing to change the injection plastic into a liquid state, or when the injection plastic is in a liquid state at room temperature, opening the electrode embedded in the injection mold to form an electric field in the cavity, and the metal particles are aggregated towards the surface layer region of the injection plastic under the action of the electric field;

[0012] Solidifying the injection plastic, removing the injection mold, and obtaining an injection-molded packaging structure.

[0013] As a further improvement of the present application, before "adding metal particles into the liquid injection plastic", further comprising the steps of:

[0014] Coating a layer of insulating material on the surface of the metal particles.

[0015] As a further improvement of the present application, before "placing the to-be-injection-molded packaging structure into the cavity of the injection mold, and filling the injection plastic into the cavity", further comprising the steps of:

[0016] Pre-placing a film in the cavity.

[0017] As a further improvement of the present application, "placing the to-be-injection-molded packaging structure into the cavity of the injection mold" specifically comprises:

[0018] Placing the packaging structure carrier side towards the positive electrode direction, and the chip side towards the negative electrode direction in the cavity.

[0019] As a further improvement of the present application, "opening the electrode provided in the injection mold" specifically comprises:

[0020] Opening the electrode after the injection plastic completely fills the cavity, and closing the electrode before the vacuum in the cavity is released.

[0021] The present application also provides a packaging device of a chip packaging structure with electromagnetic shielding function, which comprises an injection mold, and the injection mold comprises an upper mold and a lower mold respectively provided with different electrodes.

[0022] As a further improvement of the present application, the lower mold is towards the packaging structure carrier side, and a positive electrode is embedded in the lower mold, and the upper mold is towards the packaging structure chip side, and a negative electrode is embedded in the upper mold.

[0023] As a further improvement of the present application, the negative electrode embedded in the upper mold covers the surface area of the chip in the packaging structure.

[0024] The present application has the beneficial effect that: by mixing metal particles into the injection plastic, and cooperating with the plastic packaging mold provided with electrodes in the plastic packaging process, the electric field is introduced to make the metal particles complete directional movement in the liquid injection plastic, and a dense metal particle aggregation layer is formed on the surface of the injection plastic, so that the electromagnetic shielding protection effect on the internal chip is realized, and the metal particle aggregation layer formed directly in the injection process is used to replace the traditional metal shielding layer formed by plating on the outside of the packaging body, so that the production process steps are simple, and the production cost is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 is a schematic diagram of a chip packaging structure with electromagnetic shielding function in an embodiment of the present application.

[0026] Figure 2 FIG. 1 is a schematic diagram of a chip package structure with electromagnetic shielding function using sintered metal particles in an embodiment of the present application.

[0027] Figure 3 FIG. 2 is a schematic diagram of a manufacturing method of a chip package structure with electromagnetic shielding function in an embodiment of the present application.

[0028] Figure 4 FIG. 3 is a schematic diagram of adding metal particles into liquid injection material in a manufacturing method of a chip package structure with electromagnetic shielding function in an embodiment of the present application.

[0029] Figure 5 FIG. 4 is a schematic diagram of an injection mold in a packaging device of a chip package structure with electromagnetic shielding function in an embodiment of the present application.

[0030] Figure 6 FIG. 5 is a schematic diagram of a step in a manufacturing method of a chip package structure with electromagnetic shielding function in an embodiment of the present application. DETAILED DESCRIPTION

[0031] In order to make the objectives, technical solutions and advantages of the present application clearer, the technical solutions of the present application will be described below in detail with the specific embodiments of the present application and corresponding drawings. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0032] The embodiments of the present application will be described in detail below, and examples of the embodiments are shown in the drawings, in which the same or similar notations represent the same or similar elements or elements with the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary and are only used to explain the present application, and cannot be understood as limiting the present application.

[0033] For the convenience of description, the terms representing spatial relative positions are used for description in this document, such as “upper”, “lower”, “rear”, “front”, etc., which are used to describe the relationship of one unit or feature relative to another unit or feature shown in the drawings. The terms of spatial relative positions can include different positions of the device in use or work other than the positions shown in the drawings. For example, if the device in the drawings is turned over, the unit described as being “below” or “above” the other unit or feature will be “below” or “above” the other unit or feature. Therefore, the exemplary term “below” can include both the spatial positions of below and above.

[0034] As Figure 1As shown, the application provides a chip packaging structure with electromagnetic shielding function, which comprises a carrier 1, at least one chip 2 arranged on the carrier 1, and a plastic encapsulation body 3 encapsulating the chip 2.

[0035] The carrier 1 can be a substrate, a lead frame, a laminated substrate, a MIS (Molded Interconnect System) plastic encapsulation interconnection substrate, a re-distribution layer stack, or other structures known in the art, which has opposite first and second surfaces and a circuit layer electrically connected between the first and second surfaces. The carrier 1 carries and electrically connects the chip 2, and electrically connects the chip 2 with the outside through the pin circuit or conductive bump structure on the carrier 1.

[0036] The carrier 1 is provided with at least one chip 2, and other optional passive elements 4 that need to be encapsulated and protected. The passive elements 4 are common circuit components such as capacitors and resistors.

[0037] For example, in the embodiment, the substrate is respectively provided with a first chip 2a, a second chip 2b, a first passive element 4a, and a second passive element 4b. The first passive element 4a, the first chip 2a, and the second passive element 4b are arranged adjacent to each other, and the second chip 2b is arranged relatively far away from the second passive element 4b.

[0038] The plastic encapsulation body 3 is formed on the carrier 1, and the main material thereof can be a high polymer composite material with fillers such as epoxy resin, polyimide, and dry film. The plastic encapsulation body 3 further includes functional components such as curing agent, filler, accelerator, release agent, and coupling agent. The plastic encapsulation body 3 encapsulates the chip 2 and other passive elements 4, protects the chip 2 and the passive elements 4, and provides physical support for the packaging structure.

[0039] In the embodiment, the plastic encapsulation body 3 is coated on the substrate, and the first chip 2a, the second chip 2b, the first passive element 4a, and the second passive element 4b are contained in the plastic encapsulation body 3. Since the second chip 2b is arranged relatively far away from the second passive element 4b, the plastic encapsulation body 3 forms a groove 33 at this position, thereby enhancing heat dissipation and reducing the amount of injection molding material.

[0040] The surface layer region of the plastic encapsulation body 3 is gathered with metal particles, and a dense metal particle gathering layer 32 is formed. The dense metal particles 31 gathered in the surface layer region of the plastic encapsulation body 3 form a structure similar to a metal shielding layer, which can replace the metal shielding layer to play an electromagnetic shielding role. Since the metal particles 31 are directly added to the injection molding material and gathered in the surface layer region of the encapsulation body during the injection molding process, the metal shielding layer plated on the surface of the plastic encapsulation body in the conventional packaging structure with electromagnetic shielding function can be omitted.

[0041] In the embodiment, the metal particle gathering layer 32 is formed on the top surface and the side wall surface of the plastic package 3 and on both sides of the groove 33 structure.

[0042] Further, the surface of the metal particle 31 is coated with an insulating material 311 such as polyethylene. By selecting different insulating materials 311 and controlling the thickness of the insulating material 311 layer, the overall density of the metal particle 31 and the insulating material 311 layer can be adjusted, so that the metal particle 31 has good suspension characteristics in the liquid injection plastic, avoiding the problem of aggregation and precipitation of the metal particle 31 in the liquid injection plastic. Before injection, the metal particle 31 is uniformly mixed with the injection plastic.

[0043] Preferably, the particle size of the metal particle 31 is less than 10 μm. Small particle size metal particles 31 are more likely to form a dense metal gathering layer, reducing porosity, and in liquid injection plastic, small particle size metal particles 31 are more likely to be suspended and dispersed.

[0044] Preferably, as shown in Figure 2 The metal particle 31 is a sintered metal particle 31. After sintering, the metal particle 31 has high density, reducing the gap between the metal particles 31 after aggregation, forming a more dense metal particle gathering layer 32, thereby improving the shielding effect of the metal gathering layer.

[0045] Specifically, the metal particle 31 is a doped sintered silver powder particle.

[0046] As shown in Figure 3 The application also provides a chip packaging structure manufacturing method with electromagnetic shielding function, comprising the steps of:

[0047] S1: as shown in Figure 4 The metal particle 31 is added to the liquid injection plastic 3a, and the metal particle 31 is uniformly mixed with the injection plastic.

[0048] Further, before step S1, the surface of the metal particle 31 is coated with an insulating material 311 such as polyethylene.

[0049] Preferably, the particle size of the metal particle 31 is less than 10 μm, and the volume fraction of the metal particle 31 in the liquid injection plastic 3a is less than 15%, so as to avoid the problem of aggregation and precipitation of the metal particle 31 in the liquid injection plastic 3a. The specific volume fraction of the metal particle 31 in the liquid injection plastic 3a is adjusted according to the difference between the metal particle 31 and the injection plastic material, and the difference between the packaging structure and other parameters.

[0050] Preferably, the metal particle 31 is a sintered metal particle 31, such as a doped sintered silver powder particle.

[0051] S2: providing a to-be-injection-molded packaging structure, placing the to-be-injection-molded packaging structure in a mold cavity 52 of an injection mold 5, and filling the mold cavity 52 with injection plastic. The to-be-injection-molded packaging structure includes a carrier 1 and at least one chip 2 arranged on the carrier 1.

[0052] As shown in Figure 5 The injection mold 5 includes an upper mold 5a and a lower mold 5b, and opposite electrodes 51 are arranged in the upper mold 5a and the lower mold 5b, respectively. When the electrodes 51 are turned on, an electric field is formed between the upper mold 5a and the lower mold 5b, and the mold cavity 52 is located in the electric field. The metal particles 31 move along the direction of the electric field, and the to-be-injection-molded packaging structure is placed with the carrier 1 side facing the positive electrode 51 and the chip 2 side facing the negative electrode 51, so that the metal particles 31 are gathered in the surface layer region of the injection plastic on the chip 2 side, thereby forming electromagnetic shielding protection for the chip 2.

[0053] Further, in some embodiments of the present application, in order to avoid adhesion between the gathered metal particles 31 and the mold and difficulty in demolding, a film-assisted plastic packaging method is adopted, and a film 6 is prearranged in the mold cavity 52 to facilitate demolding.

[0054] S3: as shown in Figure 6 When the injection plastic is in a liquid state at room temperature, the electrodes 51 embedded in the injection mold 5 are turned on to form an electric field in the mold cavity 52, and the metal particles 31 are gathered in the surface layer region of the injection plastic under the action of the electric field.

[0055] In different embodiments, compression molding or transfer molding can be selected, and the present application does not make specific limitations in this regard. Compared with the traditional injection molding process steps, the present application adds the step of turning on the electrodes 51 when the injection plastic is in a liquid state, so that the metal particles 31 move directionally in the liquid injection plastic with better fluidity under the action of the electric field and are gathered in the surface layer region of the injection plastic.

[0056] Specifically, the electrodes 51 are turned on after the injection plastic completely fills the mold cavity 52, the electrodes 51 are turned off before the mold cavity 52 is released, and the time length for which the electrodes 51 are turned on is controlled to be 10-120 s, so as to ensure that the electric field exists for an appropriate time length, thereby ensuring that the metal particles 31 can be fully gathered in the surface layer region, and at the same time, avoiding consumption of a large amount of time in this step.

[0057] S4: curing the injection plastic, removing the injection mold 5, and obtaining an injection-molded packaging structure.

[0058] The process method for curing the injection plastic is consistent with the prior art, and thus will not be described herein.

[0059] Compared with the manufacturing method of the conventional chip packaging structure with electromagnetic shielding function, the application omits the step of plating a metal layer on the surface of the plastic package, and directly forms a metal particle aggregation layer in the surface layer area of the injection molding body during the injection molding process to play an electromagnetic shielding role, and the process steps are simple.

[0060] As shown in Figure 5 The application also provides a packaging device of a chip packaging structure with electromagnetic shielding function, and the packaging device comprises an injection molding mold 5, and the injection molding mold 5 comprises an upper mold 5a and a lower mold 5b which are respectively provided with different electrodes 51.

[0061] In the embodiment, the lower mold 5b is towards the packaging structure carrier 1 side, and a positive electrode 51b is embedded in the lower mold 5b; and the upper mold 5a is towards the packaging structure chip 2 side, and a negative electrode 51a is embedded in the upper mold 5a. Moreover, the negative electrode 51a embedded in the upper mold 5a covers the surface area of the chip 2 in the packaging structure, so that, after the electrodes 51 are opened, the electric field formed in the mold cavity 52 can completely cover the area which needs to be electromagnetically shielded and protected for the chip 2.

[0062] For example, in the embodiment, a recess is formed between the second passive element 4b and the second chip 2b in the plastic package 3, and the upper mold 5a is provided with a downward protruding part corresponding to the recess, and the negative electrode 51a is arranged on the protruding part and the inner wall surface.

[0063] In other embodiments of the application, the mold shape and the position of the electrodes 51 arranged in the mold can be adjusted according to the specific structure of the packaging structure, and the application does not make specific limitations on this.

[0064] In summary, the application introduces the electric field to make the metal particles complete directional movement in the liquid injection plastic by mixing the metal particles in the injection plastic and cooperating with the plastic packaging mold provided with the electrodes during the plastic packaging process, and forms a dense metal particle aggregation layer on the surface of the injection plastic, so as to realize the electromagnetic shielding and protection effect on the internal chip. The metal particle aggregation layer formed directly in the injection molding process is used to replace the metal shielding layer formed by plating on the outer side of the packaging body in the conventional way, the production process steps are simple, and the production cost is reduced.

[0065] It should be understood that, although the present specification is described in terms of embodiments, each embodiment does not only contain one independent technical solution, and the specification is described in this way only for the sake of clarity, and those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be combined to form other embodiments which can be understood by those skilled in the art.

[0066] The above detailed description merely illustrates preferred and possible non-limiting embodiments of the application, and is not intended to limit the scope of the application. Any equivalent embodiments or modifications made without departing from the spirit of the application should be included in the scope of the application.

Claims

1. A method for manufacturing a chip package structure with electromagnetic shielding function, characterized in that, The method comprises the steps of: adding metal particles into liquid injection plastic, and mixing the metal particles with the injection plastic uniformly; providing a packaging structure to be injection molded, placing the packaging structure to be injection molded into a mold cavity of an injection mold, and filling the injection plastic into the mold cavity; warming and pressurizing to make the injection plastic change into liquid, or when the injection plastic is liquid at room temperature, opening electrodes embedded in the injection mold, forming an electric field in the mold cavity, and making the metal particles gather towards a surface layer region of the injection plastic under the action of the electric field; wherein the step of opening the electrodes embedded in the injection mold specifically comprises: opening the electrodes after the injection plastic completely fills the mold cavity, closing the electrodes before the mold cavity is released, and controlling the time length of opening the electrodes to be 10-120s; solidifying the injection plastic, removing the injection mold, and obtaining a packaging structure after injection molding.

2. The method of claim 1, wherein the method further comprises: forming a first conductive layer on the first surface of the substrate; forming a second conductive layer on the second surface of the substrate; and forming a third conductive layer on the first surface of the substrate. Before the step of adding metal particles into liquid injection plastic, the method further comprises the step of: coating the metal particles with an insulating material.

3. The method of claim 1, wherein the method further comprises: forming a first conductive layer on the first surface of the substrate; forming a second conductive layer on the second surface of the substrate; and forming a third conductive layer on the first surface of the substrate. Before the step of placing the packaging structure to be injection molded into a mold cavity of an injection mold, and filling the injection plastic into the mold cavity, the method further comprises the step of: preparing a film in the mold cavity.

4. The method of claim 1, wherein the method further comprises: forming a first conductive layer on the first surface of the substrate; forming a second conductive layer on the second surface of the substrate; and forming a third conductive layer on the first surface of the substrate. The step of placing the packaging structure to be injection molded into a mold cavity of an injection mold specifically comprises: placing the packaging structure carrier side towards the positive electrode direction and the chip side towards the negative electrode direction in the mold cavity.

5. A packaging apparatus of a chip package structure having an electromagnetic shielding function, characterized by, The packaging device is applied to the method for manufacturing a chip packaging structure with electromagnetic shielding function according to any one of claims 1-4, and the packaging device comprises an injection mold, the injection mold comprises an upper mold and a lower mold provided with different electrodes respectively, a mold cavity for accommodating the packaging structure is formed between the upper mold and the lower mold, and the injection plastic for plastic packaging of the packaging structure can be filled in the mold cavity, an electric field can be formed between the upper mold and the lower mold when the electrodes are opened, so that a metal shielding layer is formed in a surface layer region of the injection plastic.

6. The packaging apparatus of a chip package structure having an electromagnetic shielding function according to claim 5, wherein, The lower mold is towards the packaging structure carrier side, and a positive electrode is embedded in the lower mold, the upper mold is towards the packaging structure chip side, and a negative electrode is embedded in the upper mold.

7. The packaging apparatus of a chip package structure having an electromagnetic shielding function according to claim 6, wherein, The negative electrode embedded in the upper mold covers a surface region of a chip in the packaging structure.

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