A packaging method and a packaging structure of a radio frequency module

Abstract

The application discloses a packaging method and structure of a radio frequency module. For a chip module including a filter chip and a to-be-filled chip, the chip module is assembled on a carrier plate, the bottom of the filter chip and the to-be-filled chip has a gap with the carrier plate respectively, a separation film is pre-covered on the carrier plate and the chip module, a cutting technology is used to cut the separation film on the to-be-filled chip, then a vacuum film covering process is used to make the separation film close the gap of the filter chip to form a cavity, the cutting of the separation film makes the gap of the to-be-filled chip communicate with the outside, and then plastic packaging is carried out, so that the demand of integrated packaging of the filter chip and other chips is met, and the reliability is improved. The application does not need to adjust the focal length of a laser, can realize cutting on the same horizontal plane, is convenient to operate, and does not cause damage to the carrier plate.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of semiconductor packaging, and particularly relates to a packaging method and a packaging structure of a radio frequency module. BACKGROUND

[0002] In order to meet the requirement of high packaging integration, the filter chip and other different chips / devices need to be put into the same packaging body for packaging to realize the application terminal of light and thin. The working principle of the surface acoustic wave (SAW) filter is that the input end IDT receives the voltage signal to make the piezoelectric material produce mechanical pressure and propagate in the form of acoustic wave along the surface, while the acoustic wave in the vertical direction rapidly decays, and the output end IDT receives the horizontal acoustic wave and converts it into an electric signal. Therefore, the IDT surface (i.e. functional area) cannot be in contact with other substances, and a sufficient cavity needs to be ensured for normal operation. The other types of chips need to be completely filled with plastic sealing material to ensure the reliability.

[0003] The existing integrated packaging method of the radio frequency front-end module is to first adopt the isolation film for coating to realize the cavity structure of the filter chip, and then perform plastic sealing of the plastic sealing material to isolate the influence of the external environment and impurities on the chip circuit. Due to the coating of the isolation film, the bottom of the other types of chips also forms a cavity, and in the subsequent plastic sealing process, the plastic sealing material cannot realize the filling of the bottom of the other types of chips, which will affect the reliability of the module. SUMMARY

[0004] The present application provides a packaging method and a packaging structure of a radio frequency module in view of the deficiencies of the prior art.

[0005] In order to achieve the above purpose, the technical scheme of the present application is as follows:

[0006] A packaging method of a radio frequency module, comprising the following steps:

[0007] 1) providing a carrier plate, and arranging a chip module on the carrier plate; the chip module comprises a filter chip and other chips, the filter chip has a functional surface facing the carrier plate, and a first gap is formed between the functional surface and the carrier plate, and the other chips at least comprise a to-be-filled chip, the to-be-filled chip has a lower surface facing the carrier plate, and a second gap is formed between the lower surface and the carrier plate;

[0008] 2) providing an isolation film, and coating the isolation film on the carrier plate and the chip module;

[0009] 3) adopting a cutting technology to cut the isolation film on the to-be-filled chip;

[0010] 4) using vacuum laminating process to attach the isolation film to the surface of the carrier plate and the chip module, wherein the isolation film seals the first gap to form a cavity, and the cutting of the isolation film makes the second gap communicate with the outside;

[0011] 5) molding the side of the carrier plate with the chip module to form a molding layer, and the molding material fills the second gap.

[0012] Optionally, the carrier plate is provided with a connection line, the filter chip is connected to the connection line of the carrier plate through the first protrusion at the bottom and forms the first gap, and the bottom of the filter chip has a functional area; the to-be-filled chip is connected to the connection line of the carrier plate through the second protrusion at the bottom and forms the second gap.

[0013] Optionally, the cutting technology is a laser cutting technology or an ion cutting technology.

[0014] Optionally, the laser cutting technology is to adjust the focal length of the laser to a preset height position and cut through horizontal linear movement of the light spot.

[0015] Optionally, in step 4), the pressure of the vacuum laminating is 0.9-1.0 MPa, the temperature is 100-110°C, and the pressurization time is 45-60 s.

[0016] Optionally, the laser cutting technology is to cut the isolation film around the to-be-filled chip to form a plurality of notches using a laser point cutting process, and the plurality of notches are arranged in a discrete and spaced manner; the plurality of notches form a hollow structure after vacuum laminating.

[0017] Optionally, in step 3), at least two notches are formed on the outside of the to-be-filled chip, the at least two notches are located on adjacent sides, opposite sides or multiple sides of the to-be-filled chip, and the at least two notches form a hollow structure after vacuum laminating.

[0018] Optionally, in step 3), linear cutting of the isolation film is performed around the to-be-filled chip, the position of the linear cutting is within the range of a first length of the isolation film extending from the top surface edge of the to-be-filled chip to the inside of the top surface and a second length of the isolation film extending to the outside of the top surface, and the isolation film is cut to form a separated first part and a second part, wherein the first part is located on the to-be-filled chip.

[0019] Optionally, the first length is designed such that the cutting edge of the second part after vacuum laminating is located on the surface of the carrier plate between the to-be-filled chip and the adjacent chip, and the first part is located on the top surface of the to-be-filled chip.

[0020] Optionally, the second length is designed such that the cutting edge of the first part is located on the sidewall of the chip to be filled after vacuum lamination, and the cutting edge of the second part is located on the surface of the carrier plate between the chip to be filled and the adjacent chip.

[0021] Optionally, the isolation film is an epoxy, polyimide, thermoplastic or thermosetting resin film with a thickness of 10-50 μm.

[0022] Optionally, the other chips include other functional chips and / or passive devices.

[0023] A packaging structure of a radio frequency module includes a carrier plate, a chip module, an isolation film and a plastic encapsulation layer. The chip module is arranged on the carrier plate, the isolation film is arranged on the surface of the carrier plate and the chip module, and the plastic encapsulation layer is arranged on the isolation film and covers the carrier plate and the chip module. The chip module includes a filter chip and a chip to be filled arranged adjacently. The filter chip has a functional surface facing the carrier plate, and a first gap is formed between the functional surface and the carrier plate. The chip to be filled has a lower surface facing the carrier plate, and a second gap is formed between the lower surface and the carrier plate. The isolation film includes a first part and a second part. The first part is arranged on the chip to be filled, and the second part encloses the first gap to form a closed cavity. The plastic encapsulation layer fills the second gap through the separation of the first part and the second part. The distance between the top of the chip to be filled and the carrier plate is H1, the distance between the top of the filter chip and the carrier plate is H2, and the distance between the chip to be filled and the filter chip is D1. The ratio of D1 to (D1+H1+H2) is greater than 1:5.

[0024] Optionally, the second part extends on the surface of the carrier plate near the chip to be filled with a length of D2. D2 is greater than 20 μm and less than D1.

[0025] The present application has the following advantages:

[0026] 1) The isolation film is pre-arranged on the carrier plate and the chip, and then cut on the isolation film on the chip to be filled. The isolation film is adhered to the surface of the chip and the carrier plate through a vacuum lamination process. The gap at the bottom of the filter chip is closed by the isolation film to form a cavity, which is completely isolated from the subsequent plastic encapsulation layer. The gap at the bottom of the chip to be filled is communicated with the outside through the cutting part, which facilitates the subsequent plastic encapsulation layer to enter and fill. Thus, the demand for integrated packaging of the filter chip and other chips is met, and the reliability is improved.

[0027] 2) The laser focal length does not need to be adjusted, and the same horizontal plane can be cut, which is convenient to operate and does not damage the carrier plate. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 FIG. 1 is a schematic structural diagram of a carrier plate according to an embodiment of the present application.

[0029] Figure 2 This is a schematic diagram of the structure of the carrier board and chip module combined in Example 1;

[0030] Figure 3 This is a schematic diagram of the pre-coated film structure in Example 1;

[0031] Figure 4 This is a schematic diagram of the structure after the protective layer has been peeled off in Example 1;

[0032] Figure 5 This is a schematic diagram of the laser dot cutting process in Example 1;

[0033] Figure 6 This is a top view of the structure obtained after laser spot cutting in Example 1;

[0034] Figure 7 This is a schematic diagram of the structure after secondary coating in Example 1. Figure 6 (Cross-sectional view along the a-a' direction);

[0035] Figure 8 This is another structural diagram of Example 1 after secondary coating. Figure 6 (Cross-sectional view in the b-b' direction);

[0036] Figure 9 This is a schematic diagram of the packaging structure of the radio frequency module in Example 1;

[0037] Figure 10 This is a schematic diagram of the structure of the carrier board and chip module combined in Example 2;

[0038] Figure 11 This is a schematic diagram of the pre-coated film structure in Example 2;

[0039] Figure 12 This is a schematic diagram of the structure after the protective layer has been peeled off in Example 2;

[0040] Figure 13 This is a schematic diagram of the laser cutting process in Example 2;

[0041] Figure 14 This is a schematic diagram of the structure after secondary coating in Example 2;

[0042] Figure 15 This is a top view of the structure after secondary coating in Example 2;

[0043] Figure 16 This is a schematic diagram of the packaging structure of the radio frequency module in Example 2;

[0044] Figure 17 This is a schematic diagram of the laser cutting process in Example 3;

[0045] Figure 18 This is a schematic diagram of the packaging structure of the radio frequency module in Example 3;

[0046] Figure 19 This is a top view schematic diagram of a laser cutting process in Example 4;

[0047] Figure 20 This is a top view schematic diagram of another laser cutting process in Example 4. Detailed Implementation

[0048] The present invention will be further explained below with reference to the accompanying drawings and specific embodiments. The accompanying drawings are merely illustrative to facilitate understanding of the invention, and their specific proportions can be adjusted according to design requirements. The vertical relationships of relative elements and the definitions of front / back in the graphics described herein should be understood by those skilled in the art to refer to the relative positions of the components; therefore, they can all be flipped to present the same component, and all of this should fall within the scope disclosed in this specification.

[0049] Example 1

[0050] The following combination Figures 1 to 9 The packaging method of the radio frequency module in Example 1 will be explained.

[0051] refer to Figure 1 A carrier board 1 is provided. The carrier board 1 has connection lines for realizing circuit connection, rewiring, and circuit lead-out, and can be, for example, a multilayer PCB board or a glass-based or ceramic-based packaging substrate. According to the layout of the chip module, a solder mask layer 12 is provided on the non-layout area of ​​the surface of the carrier board 1.

[0052] refer to Figure 2 The chip module, including the surface acoustic wave (SAW) filter chip 2 and other chips, is bonded to the carrier board 1 using surface mount technology. Other chips include other functional chips and / or passive devices, such as switching chips and low-noise amplifier (LNA) chips; passive devices include capacitors, resistors, and inductors. Among the other chips is the chip to be filled; in this embodiment, a chip to be filled, 3A, is used as an example. The SAW filter chip 2 and the chip to be filled, 3A, are disposed on the carrier board 1 and bonded to it via a first bump 21 and a second bump 31, respectively. The functional area of ​​the SAW filter chip 2 is on the same surface as the first bump 21. A first gap 2a, the height of the first bump 21, exists between the SAW filter chip 2 and the surface of the carrier board 1, preventing contact between the functional area of ​​the SAW filter chip 2 and the surface of the carrier board. A second gap 3a, the height of the second bump 31, exists between the chip to be filled, 3A, and the surface of the carrier board 1. Due to differences in chip size and structure, the heights of the bumps on different chips may be the same, partially the same, or different.

[0053] Pre-coating film is performed Figure 3 The dry film 4 is coated on the carrier board 1 as a separation film, which covers the surface of the surface acoustic wave filter chip 2 and the chip to be filled 3A on the carrier board 1. The dry film 4 is a thin film of epoxy resin, polyimide, thermoplastic resin or thermosetting resin, with a thickness ranging from 10 to 50 μm, for example, 20 μm, 30 μm, 40 μm or any value between them. Before pre-coating, the surface of the dry film away from the chip side is provided with a protective layer 41. After pre-coating, the dry film 4 is placed on the top surface of each chip and presents a natural state of gravity between adjacent chips or between the chip and the surface of the carrier board.

[0054] Reference Figure 4 The protective layer 41 is peeled off.

[0055] Reference Figure 5 and Figure 6 A laser point cutting process is used to cut the dry film 4 around the periphery of the chip to be filled 3A to form a plurality of discrete and spaced notches 4a. The cutting position is designed on the premise that the notches 4a are connected to the second gap 3a after the vacuum coating film is stretched. A plurality of notches 4a are preferably arranged at equal intervals around the top surface of the chip to be filled 3A, thereby forming a hollow structure on the integrated dry film. For example, for a dry film with a thickness of 20 μm, a 355 nanosecond ultraviolet laser with a power of 15-30 W is used, the focal length of the laser is adjusted to the preset height position, and the horizontal movement of the laser spot around the periphery of the chip to be filled 3A is used for point cutting.

[0056] Reference Figures 7-8 A vacuum coating process is used for secondary coating, with a pressure of 0.9-1.0 MPa and a temperature of 100-110°C, and a pressure time of 45-60 s. During the coating process, under the action of vacuum and pressure, the dry film 4 is stretched and attached to the surface of the surface acoustic wave filter chip 2, the chip to be filled 3A and the carrier board 1, thereby forming a closed cavity V at the first gap 2a of the first bump 21; for the chip to be filled 3A, the notches 4a after adsorption are located at the second gap 3a of the second bump 31 to form a hollow structure, so that the second gap 3a between the chip to be filled 3A and the surface of the substrate 1 has a window communicating with the space outside the dry film 4, wherein the width d1 of the notch 4a is about 20-40 um, and the interval d2 is about 40-60 um. Specifically, the thickness of the chip to be filled 3A is h1, the height of the second bump 31 is h2, and the notch position is at a distance L1 extending outward from the top edge of the chip to be filled 3A. Therefore, h1

[0057] Reference Figure 9, and the plastic encapsulation layer 5 is formed. In the plastic encapsulation process, the plastic encapsulation material fills the second gap 3a between the to-be-filled chip 3A and the surface of the substrate 1 through the gap 4a, thereby improving the reliability of the device. The sealed cavity V is retained due to the sealing and blocking effect of the dry film 4, and the bottom surface of the surface acoustic wave filter chip 2 has a functional area, which is located in the sealed cavity V to ensure normal operation.

[0058] The obtained packaging structure of the radio frequency module includes the carrier board 1, one or more surface acoustic wave filter chips 2, one or more other chips (taking the to-be-filled chip 3A as an example), the dry film 4, and the plastic encapsulation layer 5. The non-layout area of the surface of the carrier board 1 is provided with a solder mask layer 12. The surface acoustic wave filter chip 2 and the other chips including the to-be-filled chip 3A are arranged on the carrier board 1, and the surface acoustic wave filter chip 2 and the other chips including the to-be-filled chip 3A are respectively connected to the carrier board 1 through the bottom first bump 21 / second bump 31. The surface acoustic wave filter chip 2 has a first gap 2a with a height of the thickness of the first bump 21 with the surface of the carrier board 1, and the to-be-filled chip 3A has a second gap 3a with a height of the thickness of the second bump 31 with the surface of the carrier board 1. The dry film 4 covers the surface acoustic wave filter chip 2, the other chips including the to-be-filled chip 3A, and the surface of the carrier board 1, and the dry film 4 and the surface acoustic wave filter chip 2 and the carrier board 1 form a sealed cavity V corresponding to the first gap 2a. The dry film 4 is provided with a plurality of spaced gaps 4a corresponding to the second gap 3a, and the plastic encapsulation layer 5 covers the carrier board 1, the surface acoustic wave filter chip 2, and the other chips including the to-be-filled chip 3A. The dry film 4 separates the cavity V from the plastic encapsulation layer 5, and the plastic encapsulation material fills into the second gap 3a between the to-be-filled chip 3A and the surface of the carrier board 1 through the gap 4a.

[0059] For a plurality of other chips having a gap with the surface of the carrier board 1 and needing to be plastic-encapsulated, the above-mentioned method can also be used to form a hollow structure around the required chips to realize the filling of the subsequent plastic encapsulation layer.

[0060] In the embodiment, on the one hand, the film is pre-coated and then laser-cut, and the laser position is adjusted to a preset height position of the film. Since the film is not attached to the surface of the carrier board and the sidewall of the chip between adjacent chips or between the chip and the surface of the carrier board, the laser cutting does not damage the surface of the carrier board and the sidewall of the chip. On the other hand, the laser point cutting method has a small heat-affected zone on the dry film, can realize smaller chip spacing, higher product density and integration, has no requirement for the arrangement of the chip, is suitable for a wide range of applications, improves the production efficiency, and reduces the product cost. On the other hand, the plastic encapsulation material is filled through the gap of the hollow structure, the dry film is still an integral structure, has stable combination, ensures the sealing effect of the cavity and the encapsulation effect of the chip.

[0061] Embodiment 2

[0062] The following referencesFigures 10 to 15 The packaging method of the radio frequency module of embodiment 2 is described.

[0063] Reference Figure 10 The carrier board 1 is provided, and the non-disposed area of the surface of the carrier board 1 is provided with a solder resist layer 12. The surface mount technology is used to realize the combination of the surface acoustic wave filter chip 2 and other chips with the carrier board 1. In this embodiment, the other chips are exemplified by the LNA chip or the switch chip as the to-be-filled chip 3B and the passive device 3C. The surface acoustic wave filter chip 2 is bonded and connected with the carrier board 1 through the bottom first bump 21 and has a first gap 2b. The to-be-filled chip 3B is connected with the surface of the carrier board 1 through the second bump 32 and has a second gap 3b. The to-be-filled chip 3B is disposed between the passive device 3C and the surface acoustic wave filter chip 2.

[0064] Step 3, reference Figure 11 The dry film 4 is covered on the carrier board 1, which covers the surface acoustic wave filter chip 2, the to-be-filled chip 3B and the passive device 3C on the surface of the carrier board 1. The surface of the dry film 4 away from the chip is provided with a protective layer 41. After the pre-coating, the dry film 4 is placed on the top surface of each chip and presents a natural state of gravity between adjacent chips.

[0065] Step 4, reference Figure 12 The protective layer 41 is peeled off.

[0066] Step 5, reference Figure 13 The laser cutting process is used to cut the dry film 4 covering the to-be-filled chip 3B. The cutting position meets the following two conditions: 1. The second gap 3b is communicated with the outside after the vacuum coating film is stretched; 2. The first gap 2b of the adjacent surface acoustic wave filter chip 2 forms a sealed cavity after the vacuum coating film is stretched. Considering the chip structure, the distance between chips and other factors, the cutting position can be based on the top surface edge of the to-be-filled chip 3B, moving the first length of the isolation film to the inside of the top surface or moving the second length of the isolation film to the outside to meet the above conditions. In this embodiment, it is moving the first length of the isolation film to the inside of the top surface, that is, the cutting position is located on the top surface of the to-be-filled chip 3B.

[0067] In this embodiment, the laser line cutting is used to cut the dry film 4 around the to-be-filled chip 3B. For example, for a dry film with a thickness of 20 μm, a 15-30 W ultraviolet 355 nanosecond laser is used. The laser is adjusted to a preset height position to cut the line horizontally, so that the dry film covering the top surface of the to-be-filled chip 3B is separated from other parts at the second gap 3b.

[0068] Reference Figure 14, the second film coating is performed by vacuum film coating process, the pressure for the film coating is 0.9-1.0 MPa, the temperature is 100-110 ℃, and the pressure time is 45-60 s. During the film coating process, the dry film 4 is stretched and closely attached to the surface of each structure under the action of vacuum and pressure, the second gap 3b is communicated with the outside due to the breakage of the dry film, and the first gap 2b forms a closed cavity V. The plan view is shown in Figure 15 The cutting isolating film 4 is separated into a first part 4a and a second part 4b, the cutting edge of the first part 4a is located on the top surface of the chip to be filled 3B, and the cutting edge of the second part 4b is located on the surface of the carrier plate between the chip to be filled 3B and the adjacent chip after the vacuum film coating. This embodiment is especially suitable for the case that the dry film has a small length between the adjacent devices after the pre-film coating, and when the adjacent chip is a surface acoustic wave filter chip 2, the formation of the cavity can be ensured.

[0069] wherein the distance between the top surface of the chip to be filled 3B and the carrier plate is H1, the distance between the top surface of the filter chip 2 and the carrier plate is H2, and the distance between the chip to be filled 3B and the filter chip 2 is D1, then D1:(D1+H1+H2)≥1:5 is required. The length of the second part 4b extending on the surface of the carrier plate 1 close to the chip to be filled 3B is D2, and D2≥20 μm and D2<D1.

[0070] Reference is made to Figure 16 , and the plastic sealing is performed to form a plastic sealing layer 5. During the plastic sealing process, the plastic sealing material fills the second gap 3b, and the closed cavity V is preserved due to the sealing blocking effect of the dry film 4.

[0071] In the obtained packaging structure of the radio frequency module, the dry film covering the top surface of the chip to be filled 3B is separated from the dry film of other parts at the second gap 3b, and the plastic sealing material fills the second gap 3b. The dry film covering the top surface of the chip to be filled 3B can cover part of the top surface, the whole top surface, or extend downward from the top surface to cover the side wall of the chip to be filled 3B.

[0072] In this embodiment, the laser position is adjusted to the preset height position of the film for cutting, the laser focal length does not need to be adjusted, the requirement for precision is lower, and the operation is easier. When there are multiple other devices needing to be filled with plastic sealing material in the module, the dry film covering each other device can be cut according to the above process, and then the vacuum plastic sealing is performed after the cutting is completed.

[0073] Embodiment 3

[0074] Reference is made to Figure 17, the difference between Example 3 and Example 2 is that when laser cutting is performed, the cutting position is designed to move the second length of the isolation film outward from the top edge of the to-be-filled chip 3B, that is, the cutting position is located on the side of the to-be-filled chip 3B. For reference Figure 18 , the second length is designed to be the cutting edge of the first part 4c after vacuum coating, which is located on the side wall of the to-be-filled chip 3B to avoid affecting the second gap 3b. This embodiment is especially suitable for the case where the to-be-filled chip and the adjacent chip have a large distance or a large height difference, so that the dry film 4 has a large length between the adjacent devices after pre-coating.

[0075] Similarly, the chip height and the distance therebetween need to meet the relationship described in Example 2.

[0076] Example 4

[0077] The packaging method of the radio frequency module of Example 4 is as follows, the previous steps are as described in Example 1. Figures 1-4 .

[0078] For reference Figure 19 , when the laser cutting process is performed, the dry film 4 around the to-be-filled chip 3A is cut to form two notches 4b. In this embodiment, the to-be-filled chip 3A is a square structure, and filter chips 2 are arranged on two adjacent sides, so the two notches 4b can be located on the other two sides without filter chips to avoid affecting the packaging of the filter chips. For reference Figure 20 , in another embodiment, the distance between the two adjacent filter chips 2 on the two sides and the to-be-filled chip 3A is a first distance D3 and a second distance D4 respectively, and D4>D3, then the two notches 4b are arranged on opposite sides and one of the notches 4b is arranged on the side with the second distance D4. The opposite sides of the notches can obtain a more ideal plastic encapsulant bottom filling effect, and the notches are designed as far away from the filter chips as possible to avoid affecting the packaging of the filter chips. The subsequent vacuum coating and plastic encapsulation processes refer to Example 1.

[0079] The laser cutting process used in this embodiment can be point cutting or line cutting, and the length of a single notch is, for example, not more than the length of one side of a square chip structure. More than two notches can also be arranged as needed, on the premise that the notches are hollow structures after vacuum coating.

[0080] The above examples are described by taking the laser cutting process as an example, in addition, other precise cutting technologies such as ion cutting technology can also be used.

[0081] The packaging method and the packaging structure of the application can be applied to the packaging of the surface acoustic wave filter radio frequency module and finally applied to the communication equipment. With the development of the radio frequency front-end module and the demand of the application terminal for thinness, the corresponding packaging integration is higher and higher. The radio frequency front-end module with high integration needs to put different chips / devices into the same packaging body, and the technical scheme of the application solves the problems of large size and high cost of the existing CSP, WLP and other device packaging methods, and promotes the application of the radio frequency module.

[0082] The above embodiments are only used to further illustrate the packaging method and the packaging structure of the radio frequency module of the application, but the application is not limited to the embodiments, and any simple modification, equivalent change and modification of the above embodiments according to the technical essence of the application all fall within the protection scope of the technical scheme of the application.

Claims

1. A packaging method for an RF module, characterized in that, The method comprises the following steps: 1) providing a carrier plate, and assembling a chip module on the carrier plate; The chip module comprises a filter chip and other chips, the filter chip has a functional surface facing the carrier plate, and a first gap is formed between the functional surface and the carrier plate, the other chips at least comprise a to-be-filled chip, the to-be-filled chip has a lower surface facing the carrier plate, and a second gap is formed between the lower surface and the carrier plate; 2) providing a separation film, and covering the separation film on the carrier plate and the chip module; 3) cutting the separation film to form a plurality of notches around the periphery of the to-be-filled chip by using a laser point cutting process, and the plurality of notches are arranged in a discrete and spaced manner; 4) attaching the separation film to the surface of the carrier plate and the chip module by using a vacuum film coating process, wherein the separation film seals the first gap to form a cavity, and the plurality of notches of the separation film form a hollow structure after the vacuum film coating, so that the second gap is communicated with the outside; 5) performing plastic packaging on one side of the carrier plate with the chip module to form a plastic packaging layer, and the plastic packaging material fills the second gap.

2. The method of claim 1, wherein: The carrier plate is provided with a connection line, the filter chip is connected to the connection line of the carrier plate through a first bump at the bottom and forms the first gap, and the bottom of the filter chip has a functional area; the to-be-filled chip is connected to the connection line of the carrier plate through a second bump at the bottom and forms the second gap.

3. The method of claim 1, wherein: The laser point cutting process is to adjust the focal length of the laser to a preset height position, and cut by linear horizontal movement of the light spot.

4. The method of claim 1, wherein: In step 4), the pressure of the vacuum film coating is 0.9-1.0 MPa, the temperature is 100-110 DEG C, and the pressurization time is 45-60 s.

5. The method of claim 1, wherein: The separation film is an epoxy resin, polyimide, thermoplastic resin or thermosetting resin film, and the thickness is 10-50 μm.

6. The method of claim 1, wherein: The other chips comprise other functional chips and / or passive devices.

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