WO2022183831A1 - Radio frequency module system-in-package structure and method for manufacturing same, and electronic device - Google Patents

Abstract

Disclosed are a radio frequency module system-in-package structure and a method for manufacturing same, and an electronic device. The radio frequency module system-in-package structure comprises a substrate, a filter chip, a passive element, a flexible plastic encapsulation film and a plastic encapsulation layer, wherein the substrate has a first surface; the filter chip is arranged on the first surface, and forms a first gap with the first surface; the passive element is arranged on the first surface and is spaced apart from the filter chip; the flexible plastic encapsulation film is attached to the first surface, a surface of the filter chip and a surface of the passive element, and encloses a first cavity with the filter chip; and the plastic encapsulation layer covers the flexible plastic encapsulation film.

Description

System-in-package structure of radio frequency module and its manufacturing method and electronic device

This application claims the priority of the Chinese patent application filed on March 1, 2021 with application number 202110228132.X, the entire contents of which are incorporated herein by reference.

technical field

The present application relates to the technical field of packaging, and in particular, to a system-level packaging structure of a radio frequency module, a manufacturing method thereof, and an electronic device.

Background technique

Traditional filter packages generally use wafer-level filter packages. Surface acoustic wave filters (SAW) or bulk acoustic wave filters (BAW) are flip-chipped on ceramic substrates or organic substrates, and then a polymer film and sheet resin are used once. The pressing is produced into a cavity, which can realize the conversion between the electrical energy and the mechanical energy of the filter. However, due to the hard materials of the polymer film and sheet resin, the packaging workability is poor when a cavity is formed by one-time pressing. Generally, only a single package can be used, and other devices such as capacitors, resistors, amplifiers, and converters cannot be integrated, which cannot be realized. system-in-package.

technical problem

The main purpose of the present application is to provide a system-in-package structure of a radio frequency module, which aims to improve the integration degree of the radio frequency module.

technical solutions

In order to achieve the above-mentioned purpose, the RF module system-level packaging structure proposed in this application includes:

a substrate having a first surface;

a filter chip, the filter chip is arranged on the first surface, and a first gap is formed between the filter chip and the first surface;

a passive element, the passive element is arranged on the first surface and is arranged spaced apart from the filter chip;

a flexible plastic sealing film, the flexible plastic sealing film is attached to the first surface, the surface of the filter chip and the passive element, and surrounds the filter chip to form a first cavity; and

and a plastic sealing layer covering the flexible plastic sealing film.

In one embodiment, the material of the flexible plastic film is semi-solid resin; and/or,

The thickness of the flexible plastic sealing film is 40 μm˜50 μm.

In one embodiment, the value of the first void ranges from 20 μm to 40 μm.

In one embodiment, it also includes an amplifier chip and/or a converter chip, the amplifier chip and/or the converter chip are arranged between the first surface and the plastic packaging layer, and are respectively connected with the filter chip. The device chip and passive components are spaced apart.

In one embodiment, the first surface is provided with first solder paste balls, the flexible plastic film is provided with avoidance holes for exposing the first solder paste balls, and the amplifier chip and/or the converter chip pass through the first solder paste ball. The escape hole is fixedly connected with the first solder paste ball.

In one embodiment, the substrate includes a main body and a solder resist layer disposed on the surface of the main body, an internal circuit is formed inside the main body, and a plurality of second solder paste balls are connected to the internal circuit. The paste balls are exposed on the solder resist layer and are used for connecting with the filter chip and passive components.

In one embodiment, the RF module system-in-package structure further includes a shielding layer, and the shielding layer covers the surface of the plastic sealing layer.

In one embodiment, the substrate further includes a second surface disposed opposite to the first surface, and the second surface is provided with external pads.

According to another aspect of the present application, an electronic device is also proposed, comprising a housing and a system-in-package structure of a radio frequency module disposed in the housing, and the system-in-package structure of the radio frequency module is the above-mentioned combined type sensor.

According to yet another aspect of the present application, a method for fabricating a system-level packaging structure of a radio frequency module is proposed, comprising the following steps:

providing a substrate, and printing a plurality of spaced solder paste balls on the first surface of the substrate in advance;

attaching a filter chip to at least one of the solder paste balls, and forming a first gap between the filter chip and the first surface;

Film plastic sealing is performed on the first surface to form a flexible plastic sealing film covering the first surface and the filter chip, and the flexible plastic sealing film, the filter chip and the first surface are enclosed to form a first cavity;

Slotting the flexible plastic film, exposing the unconnected solder paste balls, and mounting the passive components on the substrate;

A second plastic sealing is performed to form a plastic sealing layer covering the flexible plastic sealing film and the passive element.

In one embodiment, after the step of performing the second plastic encapsulation to form a plastic encapsulation layer covering the flexible plastic encapsulation film and the passive element, the method further includes:

Metal sputtering is performed to form a shielding layer covering the plastic encapsulation layer.

beneficial effect

The RF module system-level packaging structure of the technical solution of the present application includes a substrate, a filter chip and a passive element arranged on the substrate, and also includes a flexible plastic film and a plastic layer covering the filter chip and the passive element. Compared with the existing hard packaging materials, it can have a good fit with the substrate, so that it can adapt to various sizes of chips or passive components, and package them on the same substrate, effectively improving the integration of the RF module. And save space and reduce costs. At the same time, the plastic packaging layer can further ensure the packaging stability of the filter chip and passive components. The system-level packaging structure of the radio frequency module enables the filter chip to perform circuit adaptation with passive components in one packaging structure, the structure is simple, and the loss of the radio frequency signal is effectively reduced, thereby improving the efficiency of the radio frequency.

Description of drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the accompanying drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only These are some embodiments of the present application. For those of ordinary skill in the art, other drawings can also be obtained according to the structures shown in these drawings without any creative effort.

1 is a cross-sectional view of an embodiment of a system-in-package structure of a radio frequency module of the present application;

2 is a cross-sectional view of another embodiment of a system-in-package structure of a radio frequency module of the present application;

FIG. 3 is a flowchart of an embodiment of a method for fabricating a system-in-package structure of a radio frequency module of the present application;

4 to 8 are structural cross-sectional views of the manufacturing method of the system-in-package structure of the radio frequency module shown in FIG. 3 during the manufacturing process;

9 to 12 are cross-sectional views of another embodiment of the RF module system-in-package structure of the present application during the fabrication process;

Description of reference numbers:

100	RF Module System-in-Package Structure	15	External pad
10	substrate	20	Converter chip (amplifier chip)
11	ontology	30	filter chip
111	first solder paste ball	30a	first cavity
113	Internal wiring	50	passive components
115	Second solder paste ball	70	Flexible plastic film
117	first surface	71	Avoid holes
119	second surface	80	Shield
13	Solder mask	90	Plastic layer

The realization, functional characteristics and advantages of the purpose of the present application will be further described with reference to the accompanying drawings in conjunction with the embodiments.

Embodiments of the present invention

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present application.

It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present application are only used to explain the relationship between various components under a certain posture (as shown in the accompanying drawings). The relative positional relationship, the movement situation, etc., if the specific posture changes, the directional indication also changes accordingly.

In this application, unless otherwise expressly specified and limited, the terms "connected", "fixed" and the like should be understood in a broad sense, for example, "fixed" may be a fixed connection, a detachable connection, or an integrated; It can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be an internal communication between two elements or an interaction relationship between the two elements, unless otherwise explicitly defined. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific situations.

In addition, descriptions such as "first", "second", etc. in this application are only for descriptive purposes, and should not be construed as indicating or implying their relative importance or implicitly indicating the number of indicated technical features. Thus, a feature delimited with "first", "second" may expressly or implicitly include at least one of that feature. In addition, the technical solutions between the various embodiments can be combined with each other, but must be based on the realization by those of ordinary skill in the art. When the combination of technical solutions is contradictory or cannot be realized, it should be considered that the combination of such technical solutions does not exist. , is not within the scope of protection claimed in this application.

The present application proposes a system-in-package structure 100 for a radio frequency module.

Referring to FIG. 1 , in an embodiment of the present application, a system-in-package structure 100 of a radio frequency module includes:

a substrate 10 having a first surface 117;

a filter chip 30, the filter chip 30 is disposed on the first surface 117, and a first gap is formed between the filter chip 30 and the first surface 117;

A passive element 50, the passive element 50 is arranged on the first surface 117 and is arranged spaced apart from the filter chip 30;

The flexible plastic sealing film 70 is attached to the first surface 117 , the surface of the filter chip 30 and the passive element 50 , and is enclosed with the filter chip 30 to form a first void cavity 30a; and

The plastic sealing layer 90 covers the flexible plastic sealing film 70 .

In this embodiment, the filter chip 30 in the system-in-package structure 100 of the radio frequency module may be a surface acoustic wave filter chip 30 (SAW chip) or a bulk acoustic wave filter chip 30 (BAW), which is not limited here. . Here, there are two filter chips 30 , which are a surface acoustic wave filter chip 30 and a bulk acoustic wave filter chip 30 respectively. When the filter chip 30 is attached to the substrate 10 , only Ni/Au can be plated on the surface thereof to play the role of anti-oxidation. The passive element 50 may be various types of elements such as capacitors and resistors, the number of which may be one or more, and can be matched with the filter chip 30 in a circuit.

Here, the material of the flexible plastic film 70 is semi-solid resin, which has good flexibility and stretchability, and has a certain viscosity. The first surface 117 has good adhesion and fit, thereby preventing foreign objects from entering the first cavity 30a and affecting the vibrator in the filter chip 30 and ensuring the normal operation of the filter chip 30 . The plastic encapsulation layer 90 is a structure formed by a plastic encapsulation process in the existing structure, and its material may be epoxy resin, etc., which will not be described in detail here. At the same time, the flexible plastic film 70 has a low modulus, which is smaller than the modulus of the plastic sealing layer 90 , and can absorb the pressure of the plastic sealing layer 90 , thereby reducing the risk of cracking of the filter chip 30 having the first cavity 30 a and realizing the tight wrapping fixed role.

The RF module system-in-package structure 100 of the technical solution of the present application includes a substrate 10 , a filter chip 30 and a passive element 50 disposed on the substrate 10 , and also includes a flexible plastic film 70 and a plastic seal covering the filter chip 30 and the passive element 50 . Layer 90, the flexible plastic film 70 can have a better fit with the substrate 10 compared to the existing rigid packaging materials, so that it can adapt to chips or passive components 50 of various sizes, and package them into the same On the substrate 10, the integration degree of the radio frequency module is effectively improved, space is saved, and cost is reduced. At the same time, the plastic packaging layer 90 can further ensure the packaging stability of the filter chip 30 and the passive element 50 . The RF module system level packaging structure 100 enables the filter chip 30 and the passive element 50 to perform circuit adaptation in one packaging structure, the structure is simple, the loss of the RF signal is effectively reduced, and the RF efficiency is improved.

Specifically, please continue to refer to FIG. 1 , the substrate 10 includes a main body 11 and a solder resist layer 13 disposed on the surface of the main body 11 , an internal circuit 113 is formed inside the main body 11 , and the internal circuit 113 is connected with a plurality of first Two solder paste balls 115 . The second solder paste balls 115 are exposed on the solder resist layer 13 and are used for connecting with the filter chip 30 and the passive element 50 .

In this embodiment, the substrate 10 is a PCB board, which includes a main body 11 and a solder resist layer 13 disposed on the surface of the main body 11 , and the main body 11 can be a ceramic substrate, for example, HTTC (High Temperature Cermeric Carrier, high temperature sintered ceramic substrate 10), or an organic matrix, which is not limited here. After the body 11 is provided, it has a first surface 117 and a second surface 119 arranged opposite to each other. First, an internal circuit 113 is formed inside the body 11 through the cooperation of the via hole and the copper tube, which is used to connect the chips and components arranged on the first surface 117. The electrical signals of the device go to the second surface 119 which is configured to be electrically connected to the device to which it is applied to transmit the electrical signals of the filter chip 30 . It can be understood that the second surface 119 is provided with external pads, so as to facilitate direct soldering in external devices.

The solder resist layer 13 is the green paint solder resist layer 13 , which can prevent interference between a plurality of solder joints for connecting various components, and the surface of the solder resist layer 13 can be set as the first surface 117 . Here, when the inner circuit 113 abuts on the first surface 117 , the second solder paste ball 115 is connected, and the second here is only for convenience and corresponding to the above, and has no meaning of order. Since the solder resist layer 13 is not conductive, the second solder paste balls 115 need to be exposed on the solder resist layer 13 so as to be electrically connected to the external filter chip 30 and the passive element 50 , which can be formed on the body 11 by printing. and form a certain height in the direction perpendicular to the first surface 117, so that when the filter chip 30 is mounted on the first surface 117, it is connected to the top of the second solder paste ball 115 to form a first gap to ensure The performance of the filter chip 30 is stable. In this way, the fixing of the filter chip 30 enables the Bump (bump) process and the SMT (Surface Mounting) process to be integrated into one, which effectively reduces the packaging cost. In addition, the material of the second solder paste balls 115 can be selected from a high melting point material, such as SnCu, with a melting point of about 230°C, which can effectively reduce the amount of the second solder paste balls 115 when the RF module system-in-package structure 100 performs client reflow. melted, so as to avoid the situation that the second solder paste balls 115 flow and short-circuit due to the expansion and extrusion of the plastic sealing layer 90 , thereby further ensuring the stability of the RF module system-level packaging structure 100 .

In an optional embodiment, the value of the first void ranges from 20 μm to 40 μm.

In this embodiment, the value of the first gap is the vertical distance between the filter chip 30 and the first surface 117 , and the vertical distance is affected by the height of the second solder paste balls 115 , that is, the height of the second solder paste balls 115 . When the height is higher, the value of the first void is larger, and when the height of the second solder paste ball 115 is smaller, the value of the first void is also smaller. Here, the value of the first gap should not be too large, otherwise the mounting of the filter chip 30 is not stable enough, and it is easy for the plastic sealing liquid to flow into the first gap, thereby affecting the vibrator. Of course, the value of the first void cannot be too small, otherwise, the fatigue resistance of the solder paste ball will be poor, and the reliability of the solder paste ball will be affected. Therefore, the value range of the first gap is set here to be 20 μm~40 μm, which can improve the reliability of solder balls while ensuring the effective operation of the filter chip 30, and further improve the stability and reliability of the system-level packaging structure 100 of the RF module. work performance.

On the basis of the above structure, in an optional embodiment, the thickness of the flexible plastic sealing film 70 is 40 μm˜50 μm.

In this embodiment, in order to ensure the stability of the filter chip 30 and the passive element 50, the thickness of the flexible plastic sealing film 70 should not be too small. The thickness of the film 70 should not be too large. Therefore, the thickness range of the flexible plastic film 70 is set to be 40 μm to 50 μm. The filter chip 30 and the passive component 50 are effectively fixed, thereby improving the structural stability of the RF module system-in-package structure 100 .

Please refer to FIG. 2 , in addition, in other embodiments, the passive element 50 may be mounted on the first surface 117 after being plastic-sealed with the plastic film, so that the plastic film does not cover the passive element 50 , and the plastic film 90 makes the passive element 50 not covered. The passive element 50 is fixed firmly.

Please refer to FIG. 1 again, the filter chip 30 and the passive element 50 are packaged in the above structure. Of course, in an optional embodiment, the RF module system-in-package structure 100 further includes an amplifier chip 20 and/or a converter The amplifier chip 20 and/or the converter chip 20 are arranged between the first surface 117 and the plastic encapsulation layer 90, and are respectively arranged at intervals from the filter chip 30 and the passive element 50 .

In this embodiment, in order to further increase the integration degree of the RF module system-in-package structure 100, the package structure further includes an amplifier chip 20 and/or a converter chip 20 (switch), and the amplifier chip 20 may be an LNA (Low Noise Amplify, low noise amplifier) or PA (Power Amplify, power amplifier). Because the front end of the RF module generally has a receiver module and a transmitter module, the transmitter module mainly includes the filter chip 30, PA and Switch, and the receiver module generally includes the filter chip 30, LNA and Switch, so as to realize The function of sending and receiving waves and converting them. In this embodiment, only one amplifier chip 20 may be arranged in the RF module system-in-package structure 100, and it may be arranged between the first surface 117 and the plastic sealing layer 90, that is, the amplifier chip 20 may be covered by a plastic sealing film. , the amplifier chip 20 can also be mounted after the plastic packaging film is plastic-sealed, which is not limited here. In this way, whether in the receiver module or in the transmitter module, the filter chip 30 and more related components are integrated into one package structure, which can further reduce the loss of the video signal and improve the RF mode. group efficiency.

Of course, in other embodiments, the converter chip 20 may also be provided in the above-mentioned RF module system-in-package structure 100; or both the amplifier chip 20 and the converter chip 20 may be provided in the RF module system-in-package structure 100 .

In order to facilitate the electrical connection of the amplifier chip 20 and/or the converter chip 20 , the first surface 117 is provided with first solder paste balls 111 , and the flexible plastic film 70 is provided with avoidance holes for exposing the first solder paste balls 111 . 71 , the amplifier chip 20 and/or the converter chip 20 are fixedly connected to the first solder paste balls 111 through the avoidance holes 71 .

In this embodiment, after the flexible plastic film 70 covers the filter chip 30 and the passive element 50 , the amplifier chip 20 and/or the converter chip 20 are mounted. At this time, in order to realize the electrical connection between the two and the internal circuit 113, the flexible plastic film 70 is subjected to hole processing to form avoidance holes 71 for exposing the first solder paste balls 111. The size of the avoidance holes 71 can be set according to the actual situation. , to ensure that the liquid can be effectively filled between the plurality of first solder paste balls 111 when the subsequent plastic sealing layer 90 is plastically sealed to form a stable structure.

In addition, in order to further increase the area of film flow, the solder resist layer 13 on the substrate 10 can also be perforated, so that the plastic encapsulation liquid can enter the bottom of the converter chip 20 or the amplifier chip 20 to be connected with the substrate 10 to increase the structural stability sex.

Optionally, the RF module system-in-package structure 100 further includes a shielding layer 80 , and the shielding layer 80 covers the surface of the plastic sealing layer 90 .

In this embodiment, in order to improve the anti-interference capability of the RF module system-level packaging structure 100, a shielding layer 80 is provided on the surface of the plastic sealing layer 90, and the shielding layer 80 can be plated on the surface of the plastic sealing layer 90 by a sputtering process. and extend to the side of the substrate 10 . Specifically, the material of the shielding layer 80 can be copper (Cu) or stainless steel (SUS, Steel Use Stainless), or double sputtering, which can improve the shielding effect and also facilitate the conduction of heat in the plastic sealing layer 90 . out, thereby improving the heat dissipation performance.

The present application also proposes an electronic device (not shown), which includes a housing and a system-in-package structure 100 for a radio frequency module disposed in the housing. For the specific structure of the system-in-package structure 100 for a radio frequency module, refer to the foregoing embodiments , since the radio frequency module system-level packaging structure 100 of the electronic device adopts all the technical solutions of the above-mentioned embodiments, it has at least all the functions brought by the technical solutions of the above-mentioned embodiments, and will not be repeated here.

The electronic device may be a wearable electronic device, such as a smart watch or a wristband, or a mobile terminal, such as a mobile phone or a notebook computer, or an electronic device with radio frequency requirements such as a TV set, which is not limited here.

Please refer to FIG. 3 to FIG. 8 , the present application further proposes a manufacturing method of a system-in-package structure 100 of a radio frequency module. The structure of the system-in-package structure 100 of a radio frequency module also refers to the system-in-package of a radio frequency module in the above-mentioned embodiment. Structure 100, in one embodiment, the fabrication method includes the following steps:

Step S1 : providing a substrate 10 , and printing a plurality of spaced solder paste balls on the first surface 117 of the substrate 10 in advance;

First, the substrate 10 includes a body 11 and a solder resist layer 13 . Internal circuits 113 have been formed in the body 11 , and several spaced solder paste balls are printed on the first surface 117 of the substrate 10 . The material of the solder paste balls is SnCu with a high melting point, with a melting point of about 230°C, which can effectively reduce the melting of the solder paste balls when the RF module system-level packaging structure 100 performs client reflow, thereby avoiding the expansion and extrusion of the plastic sealing layer 90 . The situation occurs that the second solder paste balls 115 flow and short-circuit due to the pressure.

Step S2: attaching the filter chip 30 to at least one of the solder paste balls, the filter chip 30 and the first surface 117 forming a first gap;

Among them, the height of the solder paste ball used for mounting with the filter chip 30 should be guaranteed to reach 45 μm~65 μm after curing. Only after the filter chip 30 is connected can the space of the first gap be ensured, thereby ensuring the working performance of the filter. Here, there are two filter chips 30 , one filter chip 30 is SAW, and the other filter is FBAR, which is a kind of bulk acoustic wave filter chip 30 .

Step S3 : film plastic sealing is performed on the first surface 117 to form a flexible plastic sealing film 70 covering the first surface 117 and the filter chip 30 , and the flexible plastic sealing film 70 , the filter chip 30 and the first surface 117 are enclosed to form the first cavity 30a;

Here, the material of the flexible plastic film 70 is semi-solid resin, which has good flexibility and stretchability, and has a certain viscosity. A surface 117 has good adhesion and fit. At this time, the flexible plastic film 70 is attached to the outer peripheral surface of the filter chip 30 , specifically the upper surface and the four side surfaces, and attached to the first surface 117 , thereby sealing the periphery of the first gap of the filter chip 30 , the first cavity 30a is formed to ensure that the vibrator of the filter chip 30 works normally.

Step S41 : slot the flexible plastic film 70 to expose the unconnected solder paste balls, and mount the passive component 50 on the substrate 10 .

In this embodiment, the flexible plastic film 70 is slotted by laser to form avoidance holes 71 to expose the solder paste balls that need to be connected to the passive element 50 . The size is set to ensure the stability of its installation and fixation. At the same time, for the passive component 50 with a larger size, the solder resist layer 13 of the substrate 10 can also be grooved to increase the space for film flow. For example, when the height of the solder paste ball is 20 μm, the solder resist layer 13 The height is 40 μm, so as to obtain a filling height of 60 μm, which can effectively prevent the occurrence of plastic encapsulation voids and improve the structural stability of the passive element 50 .

Step S5: performing a second plastic sealing to form a plastic sealing layer 90 covering the flexible plastic sealing film 70 and the passive element 50;

In this embodiment, the formation of the plastic encapsulation layer 90 is the same as that of the conventional plastic encapsulation process, and the material of the plastic encapsulation layer 90 can be selected from epoxy resin. At the same time, because the above-mentioned flexible plastic film 70 has a low modulus, which is smaller than the modulus of the plastic layer 90, it can absorb the pressure of the plastic layer 90, thereby reducing the risk of cracking of the filter chip 30 having the first cavity 30a, and improving the RF mode. Set system-in-package architecture 100 capabilities.

Of course, in order to prevent external devices from interfering, step S6 is also included after step S5: metal sputtering is performed to form a shielding layer 80 covering the plastic sealing layer 90;

Here, the material of the shielding layer 80 can be selected from Cu or stainless steel (SUS, Steel Use Stainless), or by double sputtering, so as to improve the shielding effect, and at the same time, it can also help to export the heat in the plastic encapsulation layer 90, so as to improve the shielding effect. Improve thermal performance. Here, in addition to covering the plastic encapsulation layer 90 , the shielding layer 80 also needs to extend to the side surface of the substrate 10 , so as to be able to be electrically connected to the internal circuit 113 to achieve an effective shielding function.

Please refer to FIG. 9 to FIG. 12 , in addition, in another embodiment, the passive component 50 and the filter chip 30 can also be mounted together, and then the flexible plastic film 70 is plastic-encapsulated, so that the passive component 50 can also be improved. Fixed stability of element 50 . In this way, laser drilling is not required, which further simplifies the process, reduces the cost, and improves the packaging stability of the system-level packaging structure 100 of the radio frequency module.

Of course, when the RF module system-in-package structure 100 further includes the converter chip 20 and/or the amplifier chip 20, the installation of the two also requires laser drilling of the flexible plastic film 70. After opening 70, the converter chip 20 and/or the amplifier chip 20 and the passive element 50 are mounted together, which can also simplify the process and reduce the cost. Since the size of the converter chip 20 and/or the amplifier chip 20 is generally large, when the laser is used for grooving, the solder resist layer 13 is also drilled to improve the structural stability.

The above descriptions are only optional embodiments of the present application and are not intended to limit the scope of the patent of the present application. Under the inventive concept of the present application, any equivalent structural transformations made by using the contents of the description and drawings of the present application, or direct/indirect Applications in other related technical fields are included in the scope of patent protection of this application.

Claims (11)

1. A radio frequency module system level packaging structure, wherein the radio frequency module system level packaging structure includes:

   a substrate having a first surface;

   a filter chip, the filter chip is arranged on the first surface, and a first gap is formed between the filter chip and the first surface;

   a passive element, the passive element is arranged on the first surface and is arranged spaced apart from the filter chip;

   a flexible plastic sealing film, the flexible plastic sealing film is attached to the first surface, the surface of the filter chip and the passive element, and surrounds the filter chip to form a first cavity; and

   and a plastic sealing layer covering the flexible plastic sealing film.
2. The system-in-package structure of a radio frequency module according to claim 1, wherein the material of the flexible plastic film is semi-solid resin; and/or,

   The thickness of the flexible plastic sealing film is 40 μm˜50 μm.
3. The system-in-package structure of a radio frequency module according to claim 1, wherein the value of the first gap ranges from 20 μm to 40 μm.
4. The system-in-package structure of a radio frequency module according to claim 1, further comprising an amplifier chip and/or a converter chip, wherein the amplifier chip and/or the converter chip are arranged on the first surface and the between the plastic encapsulation layers and spaced apart from the filter chip and the passive element respectively.
5. The system-in-package structure of a radio frequency module according to claim 4, wherein the first surface is provided with first solder paste balls, and the flexible plastic film is provided with avoidance holes for exposing the first solder paste balls, so The amplifier chip and/or the converter chip is fixedly connected to the first solder paste ball through the avoidance hole.
6. The system-in-package structure of a radio frequency module according to any one of claims 1 to 5, wherein the substrate comprises a body and a solder resist layer disposed on the surface of the body, and an internal circuit is formed inside the body, so that the A plurality of second solder paste balls are connected to the internal circuit, and the second solder paste balls are exposed on the solder resist layer and are used for connecting with the filter chip and passive components.
7. The system-in-package structure of the radio frequency module according to claim 6, wherein the system-in-package structure of the radio frequency module further comprises a shielding layer, and the shielding layer covers the surface of the plastic sealing layer.
8. The system-in-package structure of the radio frequency module according to claim 6, wherein the substrate further comprises a second surface disposed opposite to the first surface, and the second surface is provided with external pads.
9. An electronic device, comprising a casing and a radio frequency module system-level packaging structure disposed in the casing, the radio frequency module system-level packaging structure being the radio frequency module according to any one of claims 1-8 system-in-package structure.
10. A manufacturing method of a system-level packaging structure of a radio frequency module, comprising the following steps:

    providing a substrate, and printing a plurality of spaced solder paste balls on the first surface of the substrate in advance;

    attaching a filter chip to at least one of the solder paste balls, and forming a first gap between the filter chip and the first surface;

    Film plastic sealing is performed on the first surface to form a flexible plastic sealing film covering the first surface and the filter chip, and the flexible plastic sealing film, the filter chip and the first surface are enclosed to form a first cavity;

    Slotting the flexible plastic film to expose unconnected solder paste balls, and attaching passive components on the substrate;

    A second plastic sealing is performed to form a plastic sealing layer covering the flexible plastic sealing film and the passive element.
11. The method for fabricating a system-in-package structure of a radio frequency module according to claim 10, wherein after the step of performing the second plastic encapsulation to form a plastic encapsulation layer covering the flexible plastic encapsulation film and the passive element, the method further comprises: :

    Metal sputtering is performed to form a shielding layer covering the plastic encapsulation layer.