Radio frequency module

Abstract

The utility model provides a radio frequency module comprising a middle plastic package structure, the middle plastic package structure comprises a first electronic component, and the first electronic component comprises a filter chip and a non-filter chip or / and a passive component; the first plastic packaging layer at least covers the back surface and the side wall of the first electronic component; the retaining walls are positioned on two sides of the front surface of the filter chip; the isolation layer covers the retaining wall and forms a cavity with the retaining wall and the front surface of the filter chip; the isolation layer also covers at least part of the front surface of the non-filter chip or / and the passive element; the at least one rewiring layer comprises a plurality of metal circuit layers and a dielectric layer for isolating the plurality of metal circuit layers, and the metal circuit layers are electrically connected with the front surface of the first electronic element; and the first bonding pad is electrically connected with the metal circuit layer. According to the utility model, at least one rewiring layer is adopted to replace a traditional substrate to provide interconnection, so that the interconnection density is greatly improved while the thickness is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of semiconductors, and in particular to a radio frequency module. Background Art

[0002] The RF front end is the core module of the mobile terminal communication system. It is an intermediate module located between the RF transceiver and the antenna. Its function is to perform signal processing such as power amplification, filtering, and switching of RF signals. It is a necessary module for mobile terminal devices to realize wireless communication functions such as cellular network connection, Wi-Fi, Bluetooth, and GPS.

[0003] Among them, the RF front-end functional devices mainly include power amplifiers (PA), low noise amplifiers (LNA), RF switches (Switch), filters (Filter), duplexers (Duplexer) and antenna tuners, etc. Depending on the application scenario and the requirements of the integration of terminal equipment, the above devices are usually integrated to a certain extent to form modules according to the requirements of the transceiver functions and the supported frequency band range. The RF front-end module is conducive to reducing the size and improving the integration. With the development of communication technology, the overall proportion of RF front-end module products is on the rise, and will gradually replace traditional discrete devices.

[0004] Traditional RF front-end modules are realized by welding or wire bonding multiple devices on one or both sides of a prefabricated substrate and then cutting them through plastic encapsulation. As the integration level increases, the feature size gradually decreases, and the defects caused by welding, bonding, plastic encapsulation filling and other processes become increasingly difficult to overcome, and the size further encounters a bottleneck.

[0005] In addition, the number of frequency bands supported by mobile phone RF front-ends has continued to increase, from no more than 5 to more than 50 bands. This evolution has led to an exponential increase in RF front-end link devices, especially a significant increase in the number of RF filters. RF filters often use acoustic filters, which require a cavity to be formed in the device to ensure the normal operation of the filter.

[0006] In RF front-end modules, WLP (Wafer Level Packaging) with pre-built cavities is often used. ， Wafer Level Packaging) filter, the main disadvantages of this filter are: 1. The manufacturing process is complicated and the cost is high; 2. The filter wafer is thin and is very easy to break during the WLP packaging process, resulting in yield loss; 3. It is very sensitive to molding pressure during the plastic packaging process, and it is easy to cause cavity collapse and cause device failure. Utility Model Content

[0007] The utility model aims to provide a radio frequency module, which adopts at least one redistribution layer to replace the traditional substrate to provide interconnection, thereby greatly improving the interconnection density while reducing the thickness.

[0008] In order to solve the above technical problems, the utility model provides a radio frequency module, including:

[0009] An intermediate plastic packaging structure, the intermediate plastic packaging structure comprising: a first electronic component, the first electronic component comprising a filter chip and a non-filter chip or / and a passive component; a first plastic packaging layer covering at least the back and side walls of the first electronic component; retaining walls located on both sides of the front of the filter chip; an isolation layer covering the retaining walls and forming a cavity with the retaining walls and the front of the filter chip, the isolation layer also covering at least part of the front of the non-filter chip or / and the passive component;

[0010] At least one redistribution layer located on the intermediate plastic packaging structure, the redistribution layer comprising a plurality of metal circuit layers and a dielectric layer isolating the plurality of metal circuit layers, the metal circuit layer being electrically connected to the front side of the first electronic component;

[0011] A first pad is located on the redistribution layer, and the first pad is electrically connected to the metal circuit layer.

[0012] Optionally, when the first electronic component includes a filter chip and a non-filter chip, or when the first electronic component includes a filter chip, a non-filter chip and a passive component, and the passive component pad is located on the front of the passive component, the RF module also includes a shielding layer, and the shielding layer covers at least the back and side walls of the first electronic component.

[0013] Optionally, the radio frequency module further includes:

[0014] a first bump located on the first pad and a second electronic component with a second bump; and

[0015] A second plastic encapsulation layer, wherein the second plastic encapsulation layer covers the second electronic component and the side walls of the first bump.

[0016] Optionally, the second electronic component includes a non-filter chip and / or a passive component.

[0017] Optionally, the first bump is a solder ball, and a surface of the first bump is higher than a surface of the second plastic packaging layer.

[0018] Optionally, the first bump is in the form of a column; and a second pad is formed on a top surface of the first bump.

[0019] Optionally, an interdigital transducer and filter chip pads located on both sides of the interdigital transducer are formed on the front side of the filter chip; the interdigital transducer is located in the cavity, the retaining wall and the isolation layer both have openings to expose at least a portion of the filter chip pad, and the redistribution layer is electrically connected to the filter chip pad.

[0020] Optionally, the thickness of the retaining wall is greater than the sum of the thickness of the interdigital transducer and the thickness of the pad of the filter chip.

[0021] Optionally, the cross-sectional area of ​​the opening of the retaining wall on the side close to the filter chip is smaller than or equal to the cross-sectional area on the side away from the filter chip; the cross-sectional area of ​​the opening of the isolation layer on the side close to the filter chip is smaller than or equal to the cross-sectional area on the side away from the filter chip.

[0022] Optionally, a cross-sectional area of ​​the opening of the isolation layer on a side close to the filter chip is greater than or equal to a cross-sectional area of ​​an opening of the retaining wall at a corresponding position on a side away from the filter chip.

[0023] Optionally, a non-filter chip pad is formed on the front side of the non-filter chip, and the isolation layer has an opening to expose at least a portion of the non-filter chip pad; a passive component pad is formed on the front side of the passive component, and the isolation layer has an opening to expose at least a portion of the passive component pad.

[0024] Optionally, the cross-sectional area of ​​the opening of the isolation layer on the side close to the non-filter chip is smaller than or equal to the cross-sectional area on the side away from the non-filter chip; the cross-sectional area of ​​the opening of the isolation layer on the side close to the passive component is smaller than or equal to the cross-sectional area on the side away from the passive component.

[0025] In summary, the RF module provided by the present invention includes an intermediate plastic packaging structure, which includes: a first electronic component, which includes a filter chip and a non-filter chip and / or a passive component; a first plastic packaging layer that at least covers the back and side walls of the first electronic component; retaining walls located on both sides of the front of the filter chip; an isolation layer that covers the retaining walls and forms a cavity with the retaining walls and the front of the filter chip, and the isolation layer also covers at least part of the front of the non-filter chip and / or the passive component; at least one redistribution layer located on the intermediate plastic packaging structure, the redistribution layer includes multiple metal circuit layers and a dielectric layer that isolates the multiple metal circuit layers, and the metal circuit layer is electrically connected to the front of the first electronic component; a first soldering pad located on the redistribution layer, and the first soldering pad is electrically connected to the metal circuit layer. The utility model adopts at least one layer of redistribution layer to replace the traditional substrate to provide interconnection, which greatly improves the interconnection density while reducing the thickness; the utility model can realize the RF module by combining WLP filter production and fan-out packaging, and the filter cavity and module packaging are completed at the same time, which can effectively reduce the complexity of RF front-end module production; at the same time, the filter chip completes the entire packaging process with a single chip method, thereby greatly reducing the high breakage rate of the filter wafer packaging; in addition, the filter cavity will not be subjected to injection molding pressure during the entire packaging process, eliminating the cavity collapse caused by the secondary plastic packaging process. At the same time, the RF module provided by the utility model can achieve a smaller three-dimensional size and can obtain a wider range of applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a flow chart of a method for manufacturing a radio frequency module provided in one embodiment of the utility model.

[0027] Figures 2 to 10 It is a structural schematic diagram of each step of the method for manufacturing a radio frequency module provided in Example 1 of the utility model.

[0028] Figures 11 to 19 It is a schematic diagram of the structure of each step of the method for manufacturing a radio frequency module provided in the second embodiment of the present utility model.

[0029] Figure 20 to Figure 23 It is a structural schematic diagram of each step of the method for manufacturing a radio frequency module provided in Embodiment 3 of the present utility model.

[0030] Figure 24 to Figure 26 It is a structural schematic diagram of each step of the method for manufacturing a radio frequency module provided in Embodiment 4 of the present utility model.

[0031] Figures 27 to 30 It is a schematic diagram of the structures of the various steps of the method for manufacturing a radio frequency module provided in Embodiment 5 of the present utility model.

[0032] Figure 31 to Figure 34It is a structural schematic diagram of each step of the method for manufacturing a radio frequency module provided in Example 6 of the present utility model.

[0033] Figure 35 to Figure 39 It is a structural schematic diagram of each step of the method for manufacturing a radio frequency module provided in Embodiment 7 of the present utility model.

[0034] Figures 40 to 44 It is a structural schematic diagram of each step of the method for manufacturing a radio frequency module provided in Example 8 of the present utility model.

[0035] Fig.45 It is a cross-sectional schematic diagram of a retaining wall opening provided in one embodiment of the utility model.

[0036] Fig.46 It is a cross-sectional schematic diagram of an isolation layer opening provided in one embodiment of the utility model.

[0037] Description of reference numerals:

[0038] 1-temporary bonding structure; 11-carrier; 12-bonding layer; 2-filter chip; 21-filter chip substrate; 22-interdigital transducer; 23-filter chip pad; 24-side wall; 25-cavity; 3-non-filter chip; 31-non-filter chip substrate; 32-non-filter chip pad; 4-passive component; 41-passive component body; 42-passive component pad; 51-first plastic encapsulation layer; 52-second plastic encapsulation layer; 6-isolation layer; 7-rewiring layer; 71-metal circuit layer; 72-dielectric layer; 8-first pad; 9-first bump; 10-solder resist layer; 13-shielding layer; 14-second electronic component; 141-second electronic component substrate; 142-second bump; 15-second pad. DETAILED DESCRIPTION

[0039] In order to make the purpose, advantages and features of the utility model clearer, the utility model is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the drawings are all in a very simplified form and are not drawn to scale, and are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the utility model. In addition, the structure shown in the drawings is often a part of the actual structure. In particular, the emphasis of each drawing is different, and sometimes different scales are used.

[0040] As used in the present invention, the singular forms "one", "an", and "the" include plural objects, unless the content clearly indicates otherwise. As used in the present invention, the term "or" is generally used in a sense that includes "and / or", unless the content clearly indicates otherwise. As used in the present invention, the term "several" is generally used in a sense that includes "at least one", unless the content clearly indicates otherwise. As used in the present invention, the term "at least two" is generally used in a sense that includes "two or more", unless the content clearly indicates otherwise. In addition, the terms "first", "second", and "third" are used only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first", "second", and "third" may explicitly or implicitly include one or at least two of the features, unless the content clearly indicates otherwise.

[0041] Figure 1 FIG. 1 is a flow chart of a method for manufacturing a radio frequency module provided by an embodiment of the present invention. Figure 1 As shown, the method for manufacturing the radio frequency module includes the following steps:

[0042] S1: providing an intermediate plastic packaging structure, the intermediate plastic packaging structure comprising: a first electronic component, the first electronic component comprising a filter chip and a non-filter chip or / and a passive component; a first plastic packaging layer covering at least the back and side walls of the first electronic component; retaining walls located on both sides of the front of the filter chip; an isolation layer covering the retaining walls and forming a cavity with the retaining walls and the front of the filter chip, the isolation layer also covering at least part of the front of the non-filter chip or / and the passive component;

[0043] S2: forming at least one redistribution layer on the intermediate plastic packaging structure, wherein the redistribution layer is electrically connected to the front surface of the first electronic component; and

[0044] S3: forming a first pad on the redistribution layer, wherein the first pad is electrically connected to the redistribution layer.

[0045] The utility model adopts a combination of WLP filter production and fan-out packaging to realize the RF module. The filter cavity and module packaging are completed at the same time, which can effectively reduce the complexity of RF front-end module production; at the same time, the filter chip completes the entire packaging process with a single chip method, thereby greatly reducing the high breakage rate of the filter wafer packaging; secondly, at least one layer of redistribution layer is used to replace the traditional substrate to provide interconnection, which greatly improves the interconnection density while reducing the thickness; in addition, the filter cavity will not be subjected to injection molding pressure during the entire packaging process, eliminating the cavity collapse caused by the secondary plastic packaging process. At the same time, the manufacturing method described in the utility model can realize a smaller three-dimensional RF front-end module, which can obtain a wider range of applications.

[0046] The following is a detailed description of the method for manufacturing the radio frequency module of the present invention through specific embodiments.

[0047] [Example 1]

[0048] Figures 2 to 10 Schematic diagram of the structure of each step of the method for manufacturing a radio frequency module provided in the first embodiment of the present invention. Figure 1 and Figures 2 to 10 The manufacturing method of the radio frequency module provided in the embodiment of the utility model is described in detail.

[0049] In step S1, refer to Figure 8 As shown, an intermediate plastic packaging structure is provided, and the intermediate plastic packaging structure includes: a first electronic component, the first electronic component includes a filter chip 2 and a non-filter chip 3 and / or a passive component 4; a first plastic packaging layer 51 covering at least the back and side walls of the first electronic component, a retaining wall 24 located on both sides of the front of the filter chip 2, an isolation layer 6 covering the retaining wall 24 and forming a cavity 25 with the retaining wall 24 and the front of the filter chip 2, and the isolation layer 6 also covers at least part of the front of the non-filter chip 3 and / or the passive component 4.

[0050] Exemplarily, the intermediate plastic packaging structure can be formed by the following sub-steps S11 to S16. In this embodiment, the first electronic component includes the filter chip 2, the non-filter chip 3 and the passive component 4 as an example for description.

[0051] Execute sub-step S11, please refer to Figures 2 to 4 As shown, a first electronic component wafer is manufactured, wherein the first electronic component wafer includes a filter wafer, a non-filter wafer and a passive component, a retaining wall 24 is formed on the filter wafer, and the first electronic component wafer is divided into single first electronic components.

[0052] In this embodiment, a filter wafer is manufactured, a retaining wall is formed on the filter wafer, and then the filter wafer is thinned and divided into single filter chips; at the same time, a non-filter wafer is manufactured, and the non-filter wafer is thinned and divided into single non-filter chips; at the same time, passive components are manufactured and divided into single passive components.

[0053] Please refer to Figure 2 As shown, the filter chip 2 includes a filter chip substrate 21, an IDT 22 formed on the front side of the filter chip substrate 21, and filter chip pads 23 located on both sides of the IDT 22. The side on which the IDT 22 and the filter chip pads 23 are formed serves as the front side of the filter chip 2, and the other side opposite to the front side serves as the back side of the filter chip 2. The front side of the filter chip 2 and the front side of the filter chip substrate 21 are the same side.

[0054] Exemplarily, the material of the filter chip substrate 21 includes but is not limited to lithium niobate, lithium tantalate, silicon or a multilayer material with a piezoelectric material layer. The interdigital transducer 22 is a single-layer film or a multilayer film composed of metal materials such as Ti (titanium), Al (aluminum), AlCu (aluminum copper), etc., and the surface of the interdigital transducer 22 can be covered with a silicon oxide or silicon nitride passivation layer to protect the interdigital transducer 22. The filter chip pad 23 is a single-layer film or a multilayer film composed of metal materials such as Ti, Al, AlCu, etc., and the surface of the filter chip pad 23 can also be covered with a silicon oxide or silicon nitride passivation layer, and the passivation layer has an opening to expose a portion of the filter chip pad 23.

[0055] Side walls 24 are formed on both sides of the front surface of the filter chip 2. The side walls 24 are located on both sides of the filter chip substrate 21. The side walls 24 have openings to expose at least a portion of the filter chip pads 23. Fig.45 As shown, the cross-sectional area of ​​the opening of the retaining wall 24 on the side close to the filter chip 2 (only the filter chip substrate 21 and the filter chip pad 23 are shown in the figure) is smaller than the cross-sectional area on the side away from the filter chip 2, that is, in the direction perpendicular to the filter chip substrate 21, the opening is wide at the top and narrow at the bottom, so as to facilitate the formation of the subsequent redistribution layer. In another embodiment of the utility model, please refer to Figure 2 As shown, the cross-sectional area of ​​the opening of the retaining wall 24 on the side close to the filter chip 2 is equal to the cross-sectional area on the side away from the filter chip 2 .

[0056] In an embodiment of the present invention, the thickness of the retaining wall 24 is greater than the sum of the thickness of the IDT 22 and the thickness of the filter chip pad 23 to ensure the height of the cavity formed subsequently.

[0057] Exemplarily, a retaining wall material layer is first formed on the front of the filter chip 2, the retaining wall material layer covers the interdigital transducer 22, the filter chip pad 23 and the filter chip substrate 21; then the retaining wall material layer is patterned to retain the retaining wall material layers on both sides of the filter chip 2 to form retaining walls 24. The material of the retaining wall 24 can be a dry film material or photoresist with exposure characteristics, but is not limited thereto.

[0058] Please refer to Figure 3 As shown, the non-filter chip 3 includes a non-filter chip substrate 31 and a non-filter chip pad 32 formed on the front of the non-filter chip substrate 31. One side on which the non-filter chip pad 32 is formed serves as the front of the non-filter chip 3, and the other side opposite to the front serves as the back of the non-filter chip 3. The front of the non-filter chip 3 is the same side as the front of the non-filter chip substrate 31. The material of the non-filter chip substrate 31 can be selected from Si, SOI (silicon on insulator), GaAs (gallium arsenide), GaN (gallium nitride) or glass, etc., according to the device type, and the non-filter chip pad 32 can be a multilayer film composed of Cu / Al / Cu.

[0059] Please refer to Figure 4 As shown, the passive component 4 includes a passive component body 41 and a passive component pad 42 formed on the passive component body 41. In this embodiment, the passive component pad 42 is formed on the front surface of the passive component body 41; in other embodiments, the passive component pad 42 can also be formed on other surfaces of the passive component body 41, such as the side surface. The front surface of the passive component 4 is the same surface as the front surface of the passive component body 41.

[0060] The passive component 4 includes but is not limited to capacitors, inductors, resistors or LTCC filters. The passive component pad 42 is a multilayer film composed of metal materials such as Cu, Ni, Ag, Au, etc., and has no Sn layer on the surface.

[0061] Execute sub-step S12, please refer to Figure 5 As shown, a temporary bonding structure 1 is provided, and the first electronic component is mounted with its front side facing downward on the temporary bonding structure 1. In this embodiment, the filter chip 2, the non-filter chip 3 and the passive component 4 are mounted with their front sides facing downward on the temporary bonding structure 1. Figure 5In the figure, two filter chips 2, one non-filter chip 3 and one passive component 4 are shown. The number of the filter chips 2, the non-filter chips 3 and the passive component 4 is not limited in the embodiment.

[0062] Exemplarily, the temporary bonding structure 1 includes a carrier 11 and a bonding layer 12. The carrier 11 may be a hard carrier, such as a silicon wafer, a glass plate or a metal panel. When the carrier 11 is a hard carrier, the supporting effect is better. The bonding layer 12 may be a removable adhesive layer, which may be attached to the carrier 11 and may adhere to the chip or device placed thereon. After the plastic sealing is completed, the carrier 11 may be conveniently peeled off and removed. Of course, the bonding layer 12 may also be other material layers known in the art.

[0063] Execute sub-step S13, please refer to Figure 6 As shown, a first plastic encapsulation layer 51 is formed on the temporary bonding structure 1, and the first plastic encapsulation layer 51 covers the back and side walls of the first electronic component, the outer side walls of the retaining wall 24, and part of the temporary bonding structure 1. The outer side walls of the retaining wall 24 refer to the side walls of the retaining wall 24 facing the outside of the filter chip 2, or the side walls of the retaining wall 24 away from the IDT 22.

[0064] Exemplarily, the first plastic encapsulation layer 51 can be formed by transfer film, compression film, lamination, etc. The first plastic encapsulation layer 51 is a thermosetting resin material with inorganic fillers.

[0065] Execute sub-step S14, please refer to Figure 6 and Figure 7 As shown, the temporary bonding structure 1 is removed to expose the front side of the first electronic component. In this embodiment, the IDT 22 and part of the filter chip pad 23 on the front side of the filter chip 2 are exposed, and the non-filter chip pad 32 on the front side of the non-filter chip 3 and the passive component pad 42 on the front side of the passive component 4 are exposed.

[0066] Execute sub-step S15, please refer to Figure 8 As shown, an isolation layer 6 is formed on the front side of the first electronic component, and the isolation layer 6 , the retaining wall 24 and the front side of the filter chip 2 form a cavity 25 .

[0067] In this embodiment, the material of the isolation layer 6 can be a dry film material or photoresist with exposure characteristics, or a thinned glass or silicon material with specific area openings. Exemplarily, the thickness of the isolation layer 6 is not less than 3 μm, but is not limited thereto.

[0068] The isolation layer 6 has an opening corresponding to the opening of the retaining wall 24 to expose a portion of the filter chip pad 23. Fig.46 As shown, the cross-sectional area of ​​the opening of the isolation layer 6 on the side close to the filter chip 2 (only the filter chip substrate 21 and the filter chip pad 23 are shown in the figure) is smaller than the cross-sectional area on the side away from the filter chip 2, that is, the opening of the isolation layer 6 is a structure that is wide at the top and narrow at the bottom, so as to facilitate the formation of the subsequent redistribution layer. In another embodiment of the utility model, please refer to Figure 8 As shown, the cross-sectional area of ​​the opening of the isolation layer 6 on the side close to the filter chip 2 is equal to the cross-sectional area on the side away from the filter chip 2 .

[0069] In one embodiment of the utility model, the cross-sectional area of ​​the opening of the isolation layer 6 on the side close to the filter chip 2 is greater than or equal to the cross-sectional area of ​​the opening of the retaining wall 24 at the corresponding position on the side away from the filter chip 2, so as to completely expose the filter chip pad 23 exposed by the retaining wall 24.

[0070] Please continue to refer to Figure 8 As shown, the isolation layer 6 has an opening to expose at least a portion of the non-filter chip pad 32. In one embodiment of the utility model, the cross-sectional area of ​​the opening of the isolation layer 6 on the side close to the non-filter chip 3 is smaller than the cross-sectional area on the side away from the non-filter chip 3, that is, the opening of the isolation layer 6 is a structure that is wide at the top and narrow at the bottom to facilitate the formation of the subsequent redistribution layer. In another embodiment of the utility model, the cross-sectional area of ​​the opening of the isolation layer 6 on the side close to the non-filter chip 3 can also be equal to the cross-sectional area on the side away from the non-filter chip 3.

[0071] Please continue to refer to Figure 8 As shown, the isolation layer 6 has an opening to expose at least a portion of the passive component pad 42. In one embodiment of the utility model, the cross-sectional area of ​​the opening of the isolation layer 6 on the side close to the passive component 4 is smaller than the cross-sectional area on the side away from the passive component 4, that is, the opening of the isolation layer 6 is a structure that is wide at the top and narrow at the bottom to facilitate the formation of the subsequent redistribution layer. In another embodiment of the utility model, the cross-sectional area of ​​the opening of the isolation layer 6 on the side close to the passive component 4 can also be equal to the cross-sectional area on the side away from the passive component 4.

[0072] In step S2, please refer to Fig. 9 As shown, at least one redistribution layer 7 is formed on the intermediate plastic packaging structure, and the redistribution layer 7 is electrically connected to the front side of the first electronic component.

[0073] The rewiring layer 7 may include a plurality of metal circuit layers 71 and a dielectric layer 72 isolating the plurality of metal circuit layers 71. The metal circuit layer 71 covers the filter chip pad 23 exposed by the opening of the isolation layer 6 and the opening of the retaining wall 24, thereby being electrically connected to the filter chip pad 23. The metal circuit layer 71 covers the non-filter chip pad 32 and the passive component pad 42 exposed by the opening of the isolation layer 6, thereby being electrically connected to the non-filter chip pad 32 and the passive component pad 42 respectively. The material of the metal circuit layer 71 may be a metal such as copper or aluminum, and a Ti / Cu (titanium / copper) or TiW / Cu (titanium tungsten / copper) seed layer may be provided at the bottom of the metal such as copper or aluminum, and the metal circuit layer 71 may be formed by electroplating and etching. In addition to connecting the pads of each chip for signal extraction and grounding, the metal circuit layer 71 also includes a matching circuit pattern to ensure the electrical performance of the module. The dielectric layer 72 may be a dry film material or photoresist with exposure characteristics, but is not limited thereto.

[0074] In this embodiment, a multi-layer redistribution layer 7 can be formed, and the metal circuit layers 71 in the multi-layer redistribution layer 7 are electrically connected. Fig. 9 Only two layers of the redistribution layer 7 are shown, but the invention is not limited thereto. The thickness of each metal wiring layer 71 in the multi-layer redistribution layer 7 may be the same or different, and the thickness of each dielectric layer 72 in the multi-layer redistribution layer 7 may be the same or different.

[0075] In step S3, please refer to Fig.10 As shown, a first pad 8 is formed on the redistribution layer 7 , and the first pad 8 is electrically connected to the redistribution layer 7 .

[0076] The material of the first pad 8 includes but is not limited to copper, and the surface of the first pad 8 can be subjected to anti-oxidation treatment to prevent oxidation. The first pad 8 can be formed by electroplating and etching, and the first pad 8 contacts the metal wiring layer 71 in the redistribution layer 7 to achieve electrical connection.

[0077] In an embodiment of the present invention, a first bump 9 may be formed on the first pad 8. The first bump 9 may be a copper column or a solder ball.

[0078] In one embodiment of the utility model, in order to prevent short circuit during subsequent welding, a solder resist layer 10 can also be formed on the redistribution layer 7. The solder resist layer 10 is a material that is not wettable by tin. The solder resist layer 10 has an opening at the first solder pad 8 or the first bump 9 to expose the first solder pad 8 or the first bump 9.

[0079] It can then be cut into individual modules and packaged to form a single-sided RF module.

[0080] The manufacturing method of the RF module provided in this embodiment adopts a combination of WLP filter manufacturing and fan-out packaging to realize the RF module. The filter cavity and module packaging are completed at the same time, which can effectively reduce the complexity of RF front-end module manufacturing; at the same time, the filter chip completes the entire packaging process in a single chip method, thereby greatly reducing the high fragmentation rate of the filter wafer packaging; secondly, at least one layer of redistribution layer is used to replace the traditional substrate to provide interconnection, which greatly improves the interconnection density while reducing the thickness; in addition, the filter cavity will not be subjected to injection molding pressure during the entire packaging process, eliminating the cavity collapse caused by the secondary plastic packaging process. At the same time, the manufacturing method described in the utility model can realize a smaller three-dimensional RF front-end module, which can obtain a wider range of applications.

[0081] [Example 2]

[0082] Compared with implementation one, the difference of this embodiment lies in that: when the first electronic component includes a filter chip 2, a non-filter chip 3 and a passive component 4, and the passive component pad 42 is located on the front side of the passive component 4, or when the first electronic component includes a filter chip 2 and a non-filter chip 3, after the front side of the first electronic component is mounted face down on the temporary bonding structure 1, before the first plastic packaging layer 51 is formed, it also includes: forming a shielding layer 13, and the shielding layer 13 at least covers the back side, side wall and part of the temporary bonding structure 1 of the first electronic component to increase electromagnetic shielding.

[0083] In this embodiment, the first electronic component including the filter chip 2 and the non-filter chip 3 is taken as an example for description.

[0084] Figures 11 to 19 This is a schematic diagram of the structure of each step of the method for making a radio frequency module provided in the second embodiment of the present utility model. Fig.11 As shown, after the filter chip 2 and the non-filter chip 3 are mounted on the temporary bonding structure 1 with the front side facing downward, a shielding layer 13 is formed, and the shielding layer 13 covers the back and side walls of the filter chip 2, the outer side walls of the side walls 24, the back and side walls of the passive element 4, and part of the temporary bonding structure 1 (specifically the bonding layer 12 in this embodiment). The outer side wall of the retaining wall 24 refers to the side wall of the retaining wall 24 facing the outside of the filter chip 2, or refers to the side wall of the retaining wall 24 away from the side of the interdigital transducer 22.

[0085] The shielding layer 13 is made of metal material, such as a single metal layer or a multi-layer metal composite layer such as copper or nickel. The shielding layer 13 can be formed by electroplating or sputtering. The thickness of the shielding layer 13 can be greater than or equal to 1 μm, but is not limited thereto.

[0086] Then, please refer to Fig.12 As shown, a first plastic encapsulation layer 51 is formed on the temporary bonding structure 1 , and the first plastic encapsulation layer 51 covers the shielding layer 13 .

[0087] Next, the temporary bonding structure 1 is removed to expose the front side of the first electronic component. Fig.13 This is a schematic diagram of the structure after the temporary bonding structure 1 is removed. Fig.14 for Fig.13 For the cross-sectional view at AB, please refer to Fig.13 and Fig.14 As shown, the shielding layer 13 surrounds the back and side walls of the filter chip 2, the outer side wall of the barrier layer 24, the back and side walls of the non-filter chip 3, and covers the first plastic packaging layer 51 between adjacent chips.

[0088] In an embodiment of the present invention, after removing the temporary bonding structure 1 , a portion of the shielding layer 13 may also be removed to expose a portion of the first plastic packaging layer 51 . Fig.15 is a schematic diagram of the structure after removing part of the shielding layer, Fig.16 yes Fig.15 For the cross-sectional view at AB, please refer to Fig.15 and Fig.16 As shown, a portion of the shielding layer 13 is removed to expose the first plastic packaging layer 51, which is beneficial to improving the bonding strength between the subsequently formed redistribution layer and the intermediate plastic packaging structure, thereby increasing the reliability of the module.

[0089] Next, please refer to Fig.17 As shown, an isolation layer 6 is formed on the front side of the filter chip 2 and the front side of the non-filter 3. The isolation layer 6, the retaining wall 24 and the front side of the filter chip 2 constitute a cavity 25. The isolation layer 6 covers a portion of the front side of the non-filter chip 3 and exposes at least a portion of the non-filter chip pad 32, thereby forming an intermediate plastic packaging structure.

[0090] Then, please refer to Fig.18 As shown, at least one redistribution layer 7 is formed on the intermediate plastic packaging structure, the metal wiring layer 71 in the redistribution layer 7 is electrically connected to the filter chip pad 23 and the non-filter chip pad 32, and the dielectric layer 72 is used to isolate the metal wiring layer 71. Fig.19 As shown, a first pad 8 is formed on the redistribution layer 7, and the first pad 8 is electrically connected to the redistribution layer 7. Afterwards, a first bump 9 may be formed on the first pad 8, and a solder resist layer 10 exposing the first pad 8 and the first bump 9 may be formed on the redistribution layer 7.

[0091] [Example 3]

[0092] Compared with the first embodiment, the present embodiment is different in that the method of forming the intermediate plastic packaging structure is different.

[0093] Figure 20 to Figure 23 This is a schematic diagram of the structure of each step of the method for manufacturing a radio frequency module provided in Example 3 of the present utility model. First, similar to Example 1, a first electronic component wafer is manufactured, the first electronic component wafer includes a filter wafer and a non-filter wafer or / and a passive component, a retaining wall is formed on the filter wafer, and the first electronic component wafer is divided into single first electronic components.

[0094] In this embodiment, the first electronic component including the filter chip 2, the non-filter chip 3 and the passive component 4 is still used as an example for description. A filter wafer is manufactured, a retaining wall is formed on the filter wafer, and then the filter wafer is thinned and divided into single filter chips to form a filter wafer as shown in FIG. Figure 2 At the same time, a non-filter wafer is manufactured, and the non-filter wafer is thinned and then divided into single non-filter chips to form a structure as shown in FIG. Figure 3 At the same time, passive components are manufactured and divided into individual passive components to form a structure as shown in FIG. Figure 4 The structure shown.

[0095] Then, please refer to Fig. 20 As shown, a temporary bonding structure 1 is provided, and an isolation layer 6 corresponding to the retaining wall 24 is formed on the temporary bonding structure 1. This step can be performed simultaneously with the previous step. The temporary bonding structure 1 includes a carrier 11 and a bonding layer 12 formed on the carrier 11, and the isolation layer 6 is formed on the bonding layer 12.

[0096] Please refer to Fig.21 As shown, the front side of the first electronic component is mounted on the temporary bonding structure 1 with the front side facing downward, and the isolation layer 6, the retaining wall 24 and the front side of the filter chip 2 form a cavity 25. In this embodiment, the front sides of the filter chip 2, the non-filter chip 3 and the passive component 4 are mounted on the temporary bonding structure 1 with the front side facing downward. The isolation layer 6, the retaining wall 24 and the filter chip substrate 21 form a cavity 25.

[0097] Next, please refer to Fig. 22 As shown, a first plastic encapsulation layer 51 is formed on the temporary bonding structure 1, and the first plastic encapsulation layer 51 covers the back and side walls of the first electronic component, the outer side walls of the retaining wall 24 and part of the temporary bonding structure 1 (specifically the bonding layer 12).

[0098] Please refer to Fig. 22 and Fig.23As shown, the temporary bonding structure 1 is removed to expose the front surface of the first electronic component, and finally an intermediate plastic packaging structure is formed.

[0099] In this embodiment, a retaining wall 24 is first formed on the filter wafer, and then the filter wafer is divided into individual filter chips 2, and an isolation layer 6 is formed on the temporary bonding structure 1. Compared with the first embodiment, the retaining wall 24 and the isolation layer 6 can be manufactured at the same time, thereby saving process time.

[0100] [Example 4]

[0101] Compared with the third embodiment, the difference of this embodiment lies in that: when the first electronic component includes a filter chip 2, a non-filter chip 3 and a passive component 4, and the passive component pad 42 is located on the front side of the passive component 4, or when the first electronic component includes a filter chip 2 and a non-filter chip 3, after the front side of the first electronic component is mounted face down on the temporary bonding structure 1, before the first plastic packaging layer 51 is formed, it also includes: forming a shielding layer 13, and the shielding layer 13 at least covers the back side, side wall and part of the temporary bonding structure 1 of the first electronic component to increase electromagnetic shielding.

[0102] In this embodiment, the first electronic component including the filter chip 2 and the non-filter chip 3 is taken as an example for description.

[0103] Figure 24 to Figure 26 This is a schematic diagram of the structure of each step of the method for making a radio frequency module provided in the fourth embodiment of the present utility model. Fig.24 As shown, after the filter chip 2 and the non-filter chip 3 are mounted face down on the temporary bonding structure 1, a shielding layer 13 is formed, and the shielding layer 13 covers the back and side walls of the filter chip 2, the outer side walls of the side walls 24, the back and side walls of the passive element 4, and part of the temporary bonding structure 1 (specifically the bonding layer 12 in this embodiment). In this embodiment, the shielding layer 13 also covers the outer side wall of the isolation layer 6, and the outer side wall of the isolation layer 6 refers to the side wall of the isolation layer 6 corresponding to the filter chip 2 facing the outside of the filter chip 2, or refers to the side wall of the isolation layer 6 away from the side of the interdigital transducer 22.

[0104] Then, please refer to Fig.25 As shown, a first plastic encapsulation layer 51 is formed on the temporary bonding structure 1 , and the first plastic encapsulation layer 51 covers the shielding layer 13 .

[0105] Next, please refer to Fig.25 and Fig.26As shown, the temporary bonding structure 1 is removed to expose the front side of the first electronic component, that is, the front side of the filter chip 2 and the front side of the non-filter row 3 are exposed, thereby forming the intermediate plastic packaging structure.

[0106] In one embodiment of the utility model, after removing the temporary bonding structure 1, part of the shielding layer 13 can also be removed to expose part of the first plastic packaging layer 51, which is beneficial to enhance the bonding strength between the subsequently formed redistribution layer and the intermediate plastic packaging structure, thereby increasing the reliability of the module.

[0107] [Example 5]

[0108] Compared with the above embodiments, the difference of this embodiment lies in that: on the basis of any of the above embodiments, this embodiment can be based on any of the above embodiments from Embodiment 1 to Embodiment 4, after forming the first solder pad 8, a second electronic component with a second bump and a first bump are formed on the first solder pad; then a second plastic sealing layer is formed, and the second plastic sealing layer covers the second electronic component, the first bump and part of the redistribution layer; then part of the second plastic sealing layer is removed to expose the second electronic component and the first bump.

[0109] This embodiment is formed in Example 1 Fig. 9 The structure shown is used as a basis for explanation.

[0110] Figures 27 to 30 This is a schematic diagram of the structure of each step of the method for making a radio frequency module provided in the fifth embodiment of the present utility model. Fig. 27 As shown, a second electronic component 14 with a second bump 142 and a first bump 9 are formed on the first pad 8, respectively. The second electronic component 14 includes a non-filter chip and / or a passive component, and the second electronic component 14 includes a second electronic component substrate 141 and a second bump 142 formed on the front of the second electronic component substrate 141. In this embodiment, the second electronic component 14 is a non-filter chip, and the non-filter chip includes a non-filter chip substrate and a second bump formed on the front of the non-filter chip. In this embodiment, the first bump 9 is a solder ball, such as a tin ball.

[0111] Exemplarily, the first bump 9 and the second bump 142 may be welded to the first pad 8 by welding. For example, the first bump 9 is first welded to the first pad 8, and then the second bump 142 on the second electronic component 14 is welded to the first pad 8. Of course, the first bump 9 and the second bump 142 are welded to different first pads 8. Then, high-temperature reflow is performed to fix the first bump 9 and the second bump 142 to the first pad 8.

[0112] In one embodiment of the utility model, a filling glue (not shown) is arranged between the front side of the second electronic component 14 (i.e., the side close to the second bump 142) and the corresponding redistribution layer 7, and the filling glue surrounds the second bump 142 to prevent the subsequent second plastic packaging layer from being unable to fill the area.

[0113] Next, please refer to Fig.28 As shown, a second plastic encapsulation layer 52 is formed, and the second plastic encapsulation layer 52 covers the second electronic component 14, the first bumps 9 and part of the redistribution layer 7. The second plastic encapsulation layer 52 is a thermosetting resin material with inorganic fillers.

[0114] Next, please refer to Fig.29 As shown, part of the second plastic encapsulation layer 52 is removed until the second electronic component 14 and the first bump 9 are exposed. In this embodiment, a grinding method can be used to ensure that the first bump 9 is exposed on the surface of the second plastic encapsulation layer 52. Moreover, after removing part of the second plastic encapsulation layer 52, the upper part of the first bump 9 is ground away, and the first bump 9 is no longer in the shape of a solder ball, and its surface is a plane.

[0115] Then, please refer to Fig.30 As shown, part of the second plastic encapsulation layer 52 around the first convex point 9 is removed; the first convex point 9 is reflowed so that the surface of the first convex point 9 is higher than the surface of the second plastic encapsulation layer 52. That is, the top of the first convex point 9 forms an outward convex arc shape and is higher than the surface of the second plastic encapsulation layer 52 through reflow.

[0116] It can then be cut into single modules and packaged to form a double-sided RF module.

[0117] [Example 6]

[0118] Compared with the fifth embodiment, the present embodiment is different in that: Fig.18 The structure shown is used as the basis for subsequent production.

[0119] Figure 31 to Figure 34 This is a schematic diagram of the structure of each step of the method for making a radio frequency module provided in the sixth embodiment of the present utility model. Fig.31 As shown, a second electronic component 14 with a second bump 142 and a first bump 9 are formed on the first pad 8, respectively. In this embodiment, the second electronic component 14 is a non-filter chip, and the non-filter chip includes a non-filter chip substrate and a second bump formed on the front of the non-filter chip. In this embodiment, the first bump 9 is a solder ball, such as a tin ball.

[0120] Then, please refer to Fig.32 As shown, a second plastic encapsulation layer 52 is formed, and the second plastic encapsulation layer 52 covers the second electronic component 14 , the first bumps 9 and a portion of the redistribution layer 7 .

[0121] Next, please refer to Fig.33 As shown, a portion of the second plastic packaging layer 52 is removed until the second electronic component 14 and the first bump 9 are exposed.

[0122] Then, please refer to Fig.34 As shown, part of the second plastic encapsulation layer 52 around the first convex point 9 is removed; the first convex point 9 is reflowed so that the surface of the first convex point 9 is higher than the surface of the second plastic encapsulation layer 52. That is, the top of the first convex point 9 forms an outward convex arc shape and is higher than the surface of the second plastic encapsulation layer 52 through reflow.

[0123] [Example 7]

[0124] Compared with the fifth embodiment, the present embodiment is different in that: the first protrusion 9 is in the form of a column.

[0125] This embodiment can be based on any of the above embodiments one to four, after forming the first solder pad 8, form a second electronic component with a second bump and a first bump on the first solder pad; then form a second plastic layer, the second plastic layer covers the second electronic component, the first bump and part of the redistribution layer; then remove part of the second plastic layer until the second electronic component and the first bump are exposed.

[0126] This embodiment is still formed by the embodiment 1 Fig. 9 The structure shown is used as a basis for explanation.

[0127] Figure 35 to Figure 39 This is a schematic diagram of the structure of each step of the method for making a radio frequency module provided in the seventh embodiment of the present utility model. Fig.35 As shown, a first bump 9 is formed on a portion of the first pad 8. In this embodiment, the first bump 9 is a column, such as a tin column, a copper column or a nickel column. Exemplarily, the tin column, the copper column or the nickel column can be formed by electroplating, or the copper column can be formed by welding.

[0128] Please refer to Fig.36As shown, a second electronic component 14 with a second bump 142 is formed on another part of the first pad 8. The second electronic component 14 includes a non-filter chip and / or a passive component, and the second electronic component 14 includes a second electronic component substrate 141 and a second bump 142 formed on the front of the second electronic component substrate 141. In this embodiment, the second electronic component 14 is a non-filter chip, and the non-filter chip includes a non-filter chip substrate and a second bump formed on the front of the non-filter chip.

[0129] The second electronic component 14 with the second bump 142 is formed on another part of the first pad 8 by electroplating. When the first bump 9 is also formed by electroplating, the first bump 9 and the second bump 142 can be reflow soldered at the same time.

[0130] In one embodiment of the utility model, a filling glue (not shown) is arranged between the front side of the second electronic component 14 (i.e., the side close to the second bump 142) and the corresponding redistribution layer 7, and the filling glue surrounds the second bump 142 to prevent the subsequent second plastic packaging layer from being unable to fill the area.

[0131] Next, please refer to Fig.37 As shown, a second plastic encapsulation layer 52 is formed, and the second plastic encapsulation layer 52 covers the second electronic component 14, the first bumps 9 and part of the redistribution layer 7. The second plastic encapsulation layer 52 is a thermosetting resin material with inorganic fillers.

[0132] Next, please refer to Fig.38 As shown, a portion of the second plastic encapsulation layer 52 is removed until the second electronic component 14 and the first bump 9 are exposed. In this embodiment, a grinding method can be used to ensure that the first bump 9 is exposed on the surface of the second plastic encapsulation layer 52.

[0133] Then, please refer to Fig.39 As shown, a second pad 15 is formed on the upper surface of the first bump 9 , and the second pad 15 is electrically connected to the first bump 9 .

[0134] [Embodiment 8]

[0135] Compared with the seventh embodiment, the present embodiment is different in that: Fig.18 The structure shown is used as the basis for subsequent production.

[0136] Figures 40 to 44 This is a schematic diagram of the structure of each step of the method for making a radio frequency module provided in the eighth embodiment of the present utility model. Fig.40As shown, a first bump 9 is formed on the first pad 8. In this embodiment, the first bump 9 is a column, such as a tin column, a copper column or a nickel column. Exemplarily, the tin column, the copper column or the nickel column can be formed by electroplating, or the copper column can be formed by welding.

[0137] Please refer to Fig.41 As shown, a second electronic component 14 with a second bump 142 is formed on another part of the first pad 8. The second electronic component 14 and the first bump 9 are formed on different first pads 8.

[0138] The second electronic component 14 with the second bump 142 is formed on another part of the first pad 8 by electroplating. When the first bump 9 is also formed by electroplating, the first bump 9 and the second bump 142 can be reflow soldered at the same time.

[0139] Then, please refer to Fig.42 As shown, a second plastic encapsulation layer 52 is formed, and the second plastic encapsulation layer 52 covers the second electronic component 14 , the first bumps 9 and a portion of the redistribution layer 7 .

[0140] Next, please refer to Fig.43 As shown, a portion of the second plastic packaging layer 52 is removed until the second electronic component 14 and the first bump 9 are exposed.

[0141] Then, please refer to Fig.44 As shown, a second pad 15 is formed on the upper surface of the first bump 9 , and the second pad 15 is electrically connected to the first bump 9 .

[0142] It should be noted that the embodiments in this specification are described in a progressive manner, and the production methods described later focus on the differences from the methods described previously, and the similarities and similarities between the embodiments can be referred to each other.

[0143] Correspondingly, the utility model also provides a radio frequency module, which can be manufactured using the method for manufacturing the radio frequency module described in any of the above embodiments.

[0144] Please refer to Fig.10 As shown, the following is an example of a radio frequency module manufactured by the method for manufacturing the radio frequency module described in Example 1, and the radio frequency module includes:

[0145] An intermediate plastic packaging structure, the intermediate plastic packaging structure comprising: a first electronic component, the first electronic component comprising a filter chip 2, a non-filter chip 3 and a passive component 4; a first plastic packaging layer 51 covering at least the back and side walls of the first electronic component; retaining walls 24 located on both sides of the front of the filter chip 2; an isolation layer 6 covering the retaining walls 24 and forming a cavity 25 with the retaining walls 24 and the front of the filter chip 2, the isolation layer 6 also covering at least part of the front of the non-filter chip 3 and the passive component 4;

[0146] At least one redistribution layer 7 located on the intermediate plastic packaging structure, wherein the redistribution layer 7 is electrically connected to the front surface of the first electronic component; and

[0147] A first pad 8 is located on the redistribution layer 7 , and the first pad 8 is electrically connected to the redistribution layer 7 .

[0148] In this embodiment, an interdigital transducer 22 and filter chip pads 23 located on both sides of the interdigital transducer 22 are formed on the front side of the filter chip 2; the interdigital transducer 22 is located in the cavity 25, and the retaining wall 24 and the isolation layer 6 both have openings to expose at least a portion of the filter chip pad 23, and the redistribution layer 7 is electrically connected to the filter chip pad 23.

[0149] In an embodiment of the utility model, the thickness of the retaining wall 24 is greater than the sum of the thickness of the IDT 22 and the thickness of the filter chip pad 23 , so as to ensure the height of the cavity 25 .

[0150] In one embodiment of the present utility model, please refer to Fig.45 As shown, the cross-sectional area of ​​the opening of the retaining wall 24 on the side close to the filter chip 2 (only the filter chip substrate 21 and the filter chip pad 23 are shown in the figure) is smaller than the cross-sectional area on the side away from the filter chip 2, that is, the opening is wide at the top and narrow at the bottom, so as to facilitate the electrical connection between the redistribution layer 7 and the filter chip pad 23. In another embodiment of the utility model, please refer to Fig.10 As shown, the cross-sectional area of ​​the opening of the retaining wall 24 on the side close to the filter chip 2 is equal to the cross-sectional area on the side away from the filter chip 2 .

[0151] In one embodiment of the present utility model, please refer to Fig.46As shown, the cross-sectional area of ​​the opening of the isolation layer 6 on the side close to the filter chip 2 (only the filter chip substrate 21 and the filter chip pad 23 are shown in the figure) is smaller than the cross-sectional area on the side away from the filter chip 2, that is, the opening of the isolation layer 6 is a structure that is wide at the top and narrow at the bottom, so as to facilitate the electrical connection between the redistribution layer 7 and the filter chip pad 23. In another embodiment of the utility model, please refer to Fig.10 As shown, the cross-sectional area of ​​the opening of the isolation layer 6 on the side close to the filter chip 2 is equal to the cross-sectional area on the side away from the filter chip 2 .

[0152] In one embodiment of the utility model, the cross-sectional area of ​​the opening of the isolation layer 6 on the side close to the filter chip 2 is greater than or equal to the cross-sectional area of ​​the opening of the retaining wall 24 at the corresponding position on the side away from the filter chip 2, so as to completely expose the filter chip pad 23 exposed by the retaining wall 24.

[0153] A non-filter chip pad 32 is formed on the front side of the non-filter chip 3, and the isolation layer 6 has an opening to expose at least a portion of the non-filter chip pad 32; a passive component pad 42 is formed on the front side of the passive component 4, and the isolation layer 6 has an opening to expose at least a portion of the passive component pad 42.

[0154] In one embodiment of the utility model, the cross-sectional area of ​​the opening of the isolation layer 6 on the side close to the non-filter chip 3 is smaller than or equal to the cross-sectional area on the side away from the non-filter chip 3; the cross-sectional area of ​​the opening of the isolation layer 6 on the side close to the passive component 4 is smaller than or equal to the cross-sectional area on the side away from the passive component 4.

[0155] In addition, in one embodiment of the present invention, when the first electronic component includes a filter chip 2 and a non-filter chip 3 (please refer to Fig.19 As shown), or, when the first electronic component includes a filter chip 2, a non-filter chip 3 and a passive component 4, and the passive component pad 42 is located on the front of the passive component 4 (not shown), the RF module also includes a shielding layer 13, and the shielding layer 13 at least covers the back and side walls of the filter chip 2 and the back and side walls of the non-filter chip 3 to increase electromagnetic shielding. In this embodiment, the shielding layer 13 can also expose part of the first plastic packaging layer 51 to ensure the bonding force between the intermediate plastic packaging structure and the redistribution layer 7, thereby increasing the reliability of the module.

[0156] In addition, in one embodiment of the present invention, please refer to Fig.30 or Fig.44As shown, the RF module further includes: a first bump 9 located on the first pad 8 and a second electronic component 14 with a second bump 142; a second plastic encapsulation layer 52, the second plastic encapsulation layer 52 covers the sidewalls of the second electronic component 14 and the first bump 9. Please refer to Fig.30 As shown, the first bump 9 is a solder ball, and the surface of the first bump 9 is higher than the surface of the second plastic encapsulation layer 52. Fig.44 As shown, the first bump 9 is a column, and a second pad 15 is formed on the top surface of the first bump 9 .

[0157] To summarize, the RF module provided by the present invention includes an intermediate plastic packaging structure, which includes: a first electronic component, which includes a filter chip and a non-filter chip and / or a passive component; a first plastic packaging layer that at least covers the back and side walls of the first electronic component; retaining walls located on both sides of the front of the filter chip; an isolation layer that covers the retaining walls and forms a cavity with the retaining walls and the front of the filter chip, and the isolation layer also covers at least part of the front of the non-filter chip and / or the passive component; at least one redistribution layer located on the intermediate plastic packaging structure, the redistribution layer including multiple metal circuit layers and a dielectric layer that isolates the multiple metal circuit layers, and the metal circuit layer is electrically connected to the front of the first electronic component; a first soldering pad located on the redistribution layer, and the first soldering pad is electrically connected to the metal circuit layer. The utility model adopts at least one layer of redistribution layer to replace the traditional substrate to provide interconnection, which greatly improves the interconnection density while reducing the thickness; the utility model can adopt WLP filter production and fan-out packaging to realize the RF module, and the filter cavity and module packaging are completed at the same time, which can effectively reduce the complexity of RF front-end module production; at the same time, the filter chip completes the entire packaging process with a single chip method, thereby greatly reducing the high breakage rate of the filter wafer packaging; secondly, at least one layer of redistribution layer is used to replace the traditional substrate to provide interconnection, which greatly improves the interconnection density while reducing the thickness; in addition, the filter cavity will not be subjected to injection molding pressure during the entire packaging process, eliminating the cavity collapse caused by the secondary plastic packaging process. At the same time, the RF module provided by the utility model can achieve a smaller three-dimensional size and can obtain a wider range of applications.

[0158] The above description is only a description of the preferred embodiment of the utility model, and is not any limitation on the scope of the utility model. Any changes and modifications made by ordinary technicians in the field of the utility model based on the above disclosure shall fall within the scope of protection of the claims.

Claims

1. A radio frequency module, characterized in that: include: An intermediate plastic packaging structure, the intermediate plastic packaging structure comprising: a first electronic component, the first electronic component comprising a filter chip and a non-filter chip or / and a passive component; a first plastic packaging layer covering at least the back and side walls of the first electronic component; retaining walls located on both sides of the front of the filter chip; an isolation layer covering the retaining walls and forming a cavity with the retaining walls and the front of the filter chip, the isolation layer also covering at least part of the front of the non-filter chip or / and the passive component; at least one redistribution layer located on the intermediate plastic package structure, the redistribution layer comprising a plurality of metal circuit layers and a dielectric layer isolating the plurality of metal circuit layers, the metal circuit layer being electrically connected to the front side of the first electronic component; and A first pad is located on the redistribution layer, and the first pad is electrically connected to the metal circuit layer.

2. The radio frequency module according to claim 1, characterized in that: When the first electronic component includes a filter chip and a non-filter chip, or when the first electronic component includes a filter chip, a non-filter chip and a passive component, and the passive component pad is located on the front of the passive component, the RF module also includes a shielding layer, and the shielding layer at least covers the back and side walls of the first electronic component.

3. The radio frequency module according to claim 1, characterized in that: The radio frequency module also includes: a first bump located on the first pad and a second electronic component with a second bump; and A second plastic encapsulation layer, wherein the second plastic encapsulation layer covers the second electronic component and the side walls of the first bump.

4. The radio frequency module according to claim 3, characterized in that: The second electronic component includes a non-filter chip and / or a passive component.

5. The radio frequency module according to claim 3, characterized in that: The first bump is a solder ball, and the surface of the first bump is higher than the surface of the second plastic packaging layer.

6. The radio frequency module according to claim 3, characterized in that: The first bump is in the form of a column; a second pad is formed on the top surface of the first bump.

7. The radio frequency module according to claim 1, characterized in that: An interdigital transducer and filter chip pads located on both sides of the interdigital transducer are formed on the front side of the filter chip; the interdigital transducer is located in the cavity, the retaining wall and the isolation layer both have openings to expose at least part of the filter chip pads, and the redistribution layer is electrically connected to the filter chip pads.

8. The radio frequency module according to claim 7, characterized in that: The thickness of the retaining wall is greater than the sum of the thickness of the interdigital transducer and the thickness of the pad of the filter chip.

9. The radio frequency module according to claim 7, characterized in that: The cross-sectional area of ​​the opening of the retaining wall on the side close to the filter chip is smaller than or equal to the cross-sectional area on the side away from the filter chip; the cross-sectional area of ​​the opening of the isolation layer on the side close to the filter chip is smaller than or equal to the cross-sectional area on the side away from the filter chip.

10. The radio frequency module according to claim 7, characterized in that: The cross-sectional area of ​​the opening of the isolation layer at a side close to the filter chip is greater than or equal to the cross-sectional area of ​​the opening of the retaining wall at a corresponding position at a side away from the filter chip.

11. The radio frequency module according to claim 1, characterized in that: A non-filter chip pad is formed on the front side of the non-filter chip, and the isolation layer has an opening to expose at least a portion of the non-filter chip pad; a passive component pad is formed on the front side of the passive component, and the isolation layer has an opening to expose at least a portion of the passive component pad.

12. The radio frequency module according to claim 11, characterized in that: The cross-sectional area of ​​the opening of the isolation layer on the side close to the non-filter chip is smaller than or equal to the cross-sectional area on the side away from the non-filter chip; the cross-sectional area of ​​the opening of the isolation layer on the side close to the passive component is smaller than or equal to the cross-sectional area on the side away from the passive component.

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