Radio frequency unit, method of manufacturing a radio frequency unit, and communication device

Abstract

The application relates to the technical field of semiconductor packaging, in particular to a radio frequency unit; the unit comprises a substrate; a semiconductor device module is arranged on the substrate, and the semiconductor device module comprises a filter chip and a to-be-filled device; the filter chip has a first end closest to a first edge of the substrate and a second end farthest from the first edge of the substrate, the first end is arranged at a first distance from the first edge of the substrate, and the second end is arranged at a second distance from the first edge of the substrate; the to-be-filled device has a third end closest to the first edge of the substrate and a fourth end farthest from the first edge of the substrate, the third end is arranged at a third distance from the first edge of the substrate, and the fourth end of the to-be-filled device is arranged at a fourth distance from the first edge of the substrate; the third distance and the fourth distance are not simultaneously between the first distance and the second distance. The radio frequency unit adopting the application can centrally arrange the filter chip in the module, realizes centralized film coating area, saves the film coating area, and reduces the cost.

Description

Technical Field

[0001] This invention relates to the field of semiconductor packaging technology, and in particular to a radio frequency (RF) unit, a method for manufacturing the RF unit, and a communication device. Background Technology

[0002] With the development of RF front-end modules and the increasing demand for thinner and lighter designs in application terminals, the corresponding packaging integration is also becoming increasingly sophisticated. Highly integrated RF front-end modules require placing various types of chips / components into the same package. One such component is the piezoelectric filter chip. Its working principle involves the input IDT receiving a voltage signal, causing the piezoelectric material to generate mechanical pressure, which propagates along the surface as sound waves. The vertical sound wave amplitude attenuates rapidly. The output IDT receives the horizontal sound waves and converts them into electrical signals. Therefore, the IDT surface cannot come into contact with other materials; sufficient cavity space is essential for proper operation.

[0003] Therefore, in existing technologies, filter chips require a sealed cavity at their bottom to allow specific frequency components of a signal to pass through while significantly attenuating or filtering other frequency components, ensuring normal operation. However, during the isolation film coating process, other components such as switches and power amplifiers also have cavities at their bottoms due to the isolation film coating. In subsequent molding processes, the molding layer cannot fill these cavities. Consequently, in the resulting filter module, the cavities at the bottom of the components affect the reliability of the entire filter module, ultimately causing product quality issues. Specifically, the cavities at the bottom of the components, under incomplete vacuum conditions, can lead to internal gas expansion during multiple high-temperature processes, causing the product to burst and break. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a radio frequency unit, a method for manufacturing the radio frequency unit, and a communication device.

[0005] To address the aforementioned technical problems, a first aspect of the present invention provides a radio frequency unit, comprising:

[0006] A substrate having a first surface and an opposing second surface;

[0007] A semiconductor device module is disposed on a first surface of the substrate, the semiconductor device module comprising one or more filter chips and one or more devices to be filled;

[0008] The filter chip has a lower surface facing the substrate, and a first gap is formed between the lower surface of the filter chip and a first surface of the substrate; in the one or more filter chips, there is a first end closest to the first edge of the substrate and a second end farthest from the first edge of the substrate, the first end is disposed at a first distance from the first edge of the substrate, and the second end is disposed at a second distance from the first edge of the substrate;

[0009] The device to be filled has a lower surface facing the substrate, and a second gap is formed between the lower surface of the device to be filled and a first surface of the substrate; each of the devices to be filled has a third end closest to the first edge of the substrate and a fourth end farthest from the first edge of the substrate, the third end being disposed at a third distance from the first edge of the substrate, and the fourth end being disposed at a fourth distance from the first edge of the substrate.

[0010] The third and fourth distances of any of the devices to be filled are not simultaneously located between the first and second distances.

[0011] In a preferred embodiment, the horizontal distance between the fourth end and the second end is not less than 150 μm, or the horizontal distance between the third end and the first end is not less than 150 μm.

[0012] In a preferred embodiment, the fourth distance is greater than the third distance, which is greater than the second distance, which is greater than the first distance; or

[0013] The fourth distance is greater than the second distance, which is greater than the third distance, which is greater than the first distance; or

[0014] The fourth distance is greater than the second distance, which is greater than the first distance, which is greater than the third distance; or

[0015] The second distance is greater than the fourth distance, which is greater than the first distance, which is greater than the third distance; or

[0016] The second distance is greater than the first distance, which is greater than the fourth distance, which is greater than the third distance.

[0017] In a preferred embodiment, the device to be filled includes one or more of a power amplifier, a low-noise amplifier, or a switch.

[0018] In a preferred embodiment, electrodes are provided on the lower surfaces of both the filter chip and the device to be filled; an electrode region is provided on the first surface of the substrate, which is respectively connected to the electrodes of the filter chip and the electrodes of the device to be filled; and a solder resist layer is provided on the first surface of the substrate surrounding the first electrode region and the second electrode region.

[0019] In a preferred embodiment, the radio frequency unit further includes: an isolation film disposed on a substrate, the isolation film covering the filter chip to form a closed cavity in the first gap; and the isolation film covering at most three sides of the device to be filled.

[0020] In a preferred embodiment, the radio frequency unit further includes a molding compound layer disposed on the substrate, the molding compound layer covering the isolation film and the device to be filled without covering the isolation film, and filling the second gap.

[0021] In a preferred embodiment, the radio frequency unit includes a plurality of filter chips arranged in the same orientation.

[0022] In a preferred embodiment, the device to be filled and the filter chip are positioned in the same orientation.

[0023] A second aspect of the present invention provides a method for manufacturing a radio frequency unit, comprising the following steps:

[0024] 1) Provide a substrate and a plurality of semiconductor device modules in a radio frequency unit as described above, the substrate having a first surface and an opposing second surface, wherein an electrode region and a solder resist layer surrounding the electrode region are disposed on the first surface of the substrate;

[0025] 2) Multiple semiconductor device modules are disposed on the first surface of the substrate and connected to corresponding electrode regions respectively; the multiple semiconductor device modules are arranged in a matrix, and adjacent semiconductor device modules are mirror-distributed in the longitudinal or transverse direction;

[0026] 3) An isolation film is attached to the first surface of the substrate, the isolation film covering the filter chip so that the first gap forms a closed cavity; and the isolation film covers at most three sides of the device to be filled;

[0027] 4) Forming a molding compound layer, the molding compound layer covering the release liner and the device to be filled without the release liner, and filling the second gap;

[0028] 5) Cut the product obtained in step 4) to obtain individual radio frequency units.

[0029] In a preferred embodiment, the separator is a plurality of strip-shaped separators.

[0030] A fourth aspect of the present invention provides a communication device having a radio frequency unit as described above.

[0031] In summary, this application includes at least one of the following beneficial technical effects:

[0032] 1. The bottom of the device to be filled can be filled with a molding compound, thereby improving the reliability of the product;

[0033] 2. The radio frequency unit provided by the present invention designs the arrangement of filter chips and devices to be filled, so that the filter chip constituting area in the packaging structure is concentrated. Only this area needs to be coated, thus achieving concentrated coating area, saving coating area, reducing cost, and greatly simplifying process steps.

[0034] Other features and beneficial effects of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other beneficial effects of the invention can be realized and obtained by means of the structures particularly pointed out in the description, claims and drawings. Attached Figure Description

[0035] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Unless otherwise specified, the positional relationships shown in the drawings in the following description are based on the direction in which the components are drawn in the figure.

[0036] Figure 1 A top view of the radio frequency unit provided in the first embodiment of the present invention;

[0037] Figure 2 yes Figure 1 The cross-sectional view of the radio frequency unit along the A-A' section line is shown;

[0038] Figure 3 This is a schematic diagram of the positional structure of the devices to be filled and the filter chip within the radio frequency unit provided in an embodiment of the present invention;

[0039] Figure 4 This is a top view schematic diagram of the radio frequency unit provided in the first embodiment of the present invention;

[0040] Figure 5 and Figure 6 This is a top view schematic diagram of the filter RF module packaging structure provided in the first embodiment of the present invention;

[0041] Figure 7 for Figure 6 A top view of the structural diagram of a variant of the example shown;

[0042] Figure 8 This is a top view schematic diagram of the radio frequency unit provided in the second embodiment of the present invention;

[0043] Figure 9 This is a top view schematic diagram of the filter RF module packaging structure provided in the second embodiment of the present invention;

[0044] Figure 10 This is a top view schematic diagram of the radio frequency unit provided in the third embodiment of the present invention;

[0045] Figure 11 This is a top view of the filter RF module packaging structure provided in the third embodiment of the present invention;

[0046] Figure 12 This is a top view schematic diagram of the radio frequency unit provided in the fourth embodiment of the present invention;

[0047] Figure 13 This is a top view schematic diagram of the filter RF module packaging structure provided in the fourth embodiment of the present invention;

[0048] Figure 14 This is a top view of the radio frequency unit provided in the fifth embodiment of the present invention;

[0049] Figure 15 and Figure 16 This is a top view of the filter RF module packaging structure provided in the fifth embodiment of the present invention;

[0050] Figure 17 for Figure 16 A top view of the structural diagram of a variant of the example shown;

[0051] Figure 18 A schematic diagram showing the side structure of the device to be filled covered by an isolation membrane.

[0052] Figures 19-20 This is a schematic diagram of the manufacturing process of the filter RF module packaging structure according to the first embodiment of the present invention.

[0053] Figure label:

[0054] 10. Substrate; 10a. First surface; 10b. Second surface; 11. Solder resist layer; 12. First electrode region; 13. Second electrode region; 14. Enclosed cavity; 15. First edge; 20. Semiconductor device module; 21. Filter chip; 21a. First end; 21b. Second end; 211. Interdigital transducer; 212. First electrode; 22. Device to be filled; 22a. Third end; 22b. Fourth end; 221. Second electrode; 30. Isolation film; 40. Molding layer. Detailed Implementation

[0055] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. The technical features designed in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0056] In the description of this invention, it should be noted that all terms used in this invention (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains, and should not be construed as limiting the invention; it should be further understood that the terms used in this invention should be understood to have the same meaning as those in the context of this specification and in the relevant field, and should not be understood in an idealized or overly formal sense, except as expressly defined in this invention.

[0057] The technical solutions of the present invention will be further illustrated and described below through specific embodiments. However, the scope of protection of the present invention is not limited thereto. The same reference numerals and / or markings may be used repeatedly in the different embodiments disclosed below. These repetitions are for the purpose of simplification and clarity and are not intended to limit the specific relationship between the different embodiments and / or structures discussed.

[0058] Figure 1 The diagram shown is a top view of a radio frequency unit according to the first embodiment of the present invention; Figure 2 The radio frequency unit is along Figure 1 The A-A' section line shows; in Figure 1 In the diagram, a top view is used to schematically remove [something]. Figure 2 The structure of the solder resist layer 11, the release film 30, and the plastic sealant layer 40.

[0059] Please refer to Figure 1 In the first embodiment, the radio frequency unit includes: a substrate 10, a semiconductor device module 20, an isolation film 30, and a molding compound 40;

[0060] Substrate 10 can be a composite piezoelectric substrate formed by RDL wiring layer process, or it can be a PCB substrate, such as... Figure 1 and Figure 2As shown, in the first embodiment, the substrate 10 has a first surface 10a and a second surface 10b opposite to each other. The first surface 10a of the substrate 10 is provided with a solder resist layer 11, a first electrode region 12, a second electrode region 13 and a semiconductor device module 20. The solder resist layer 11 is disposed around the first electrode region 12 and the second electrode region 13. The solder resist layer 11 can be made of different materials as needed, such as dry film, DAF film, green paint, insulating tape, epoxy resin film, phenolic resin film, polyimide film or liquid crystal polymer film, etc.

[0061] The semiconductor device module 20 includes a filter chip 21 and a device to be filled 22 disposed on the first surface 10a of the substrate 10. It should be noted that, preferably, the filter chip 21 and the device to be filled 22 are formed in their own relatively independent mounting distribution, such as left-right distribution, top-bottom distribution, diagonal distribution, etc., to facilitate subsequent centralized coating. Preferably, the radio frequency unit may include multiple filter chips 21, which are arranged in the same orientation. Taking a filter chip 21 with a rectangular shape in top view as an example, the multiple filter chips 21 can be arranged in the length direction or in the width direction, which is beneficial for centralized coating. Preferably, the device to be filled 22 is also arranged in the same orientation as the filter chip 21.

[0062] For details, please refer to Figure 1 and Figure 2 The filter chip 21 can be a surface acoustic wave (SAW) filter chip. The filter chip 21 is mounted on the first surface 10a of the substrate 10. In a preferred embodiment, the filter chip 210 is mounted on the first surface 10a of the substrate 10 using a flip-chip method. Figure 2 As shown, the side of the filter chip 21 facing the substrate 10 is taken as the lower surface. An interdigital transducer 211 and a first electrode 212 are disposed on the lower surface. The interdigital transducer 211 is used to realize the filtering function of the filter chip 21. The first electrode 212 is connected to the first electrode region 12, that is, the first electrode 212 is connected to the first electrode region 12 preset on the substrate 10, so as to realize the connection between the filter chip 21 and the outside world. A first gap is formed between the lower surface of the filter chip 21 facing the substrate 10 and the substrate 10. Preferably, for the surface of the substrate 10 with a preset solder resist layer 11, there is also a gap between the lower surface of the filter chip 21 and the solder resist layer 11.

[0063] Please also refer to Figure 3 and Figure 4The one or more filter chips 21 have a first end 21a that is closest to the first edge 15 of the substrate 10 and a second end 21b that is furthest from the first edge 15 of the substrate 10. The first end 21a is disposed at a first distance L1 from the first edge 15 of the substrate 10, and the second end 21b is disposed at a second distance L2 from the first edge 15 of the substrate 10.

[0064] It should be noted that if there is a single filter chip 21, the first end 21a and the second end 21b refer to the farthest end and the closest end of the filter chip 21 from the first edge 15 of the substrate 10, respectively. If there are multiple filter chips 21, the first end 21a and the second end 21b refer to the farthest end of the filter chip 21 farthest from the first edge 15 of the substrate 10 and the closest end of the filter chip 21 closest to the first edge 15, respectively. Therefore, when there are multiple filter chips 21, the first end 21a and the second end 21b may be on the same filter chip 21 or they may not be on the same filter chip 21.

[0065] Please continue to refer to this. Figure 1 and Figure 2 One or more devices 22 to be filled can be disposed on the substrate 10. These devices 22 can be power amplifiers (PAs), low-noise amplifier chips, RF switches, etc., or other types of functional devices, such as passive devices. Passive devices can refer to surface-mount capacitors / resistors / inductors, or combinations thereof. In the first embodiment, as... Figure 2 As shown in the figure, this embodiment schematically illustrates two devices 22 to be filled, one being a switching device or LNA device located in the middle, and the other being a passive device located on the left side of the figure. The devices 22 to be filled are mounted on the first surface 10a of the substrate 10. In a preferred embodiment, the devices 22 to be filled can be mounted on the first surface 10a of the cover substrate 10 in a flip-chip manner. The side of the devices 22 to be filled facing the substrate 10 is the lower surface, on which a second electrode 221 is disposed. The second electrode 221 is connected to the second electrode region 13, that is, the second electrode 221 is connected to the second electrode region 13 preset on the substrate 10, for realizing the connection between the devices 22 to be filled and the outside world. A second gap is formed between the lower surface of the devices 22 to be filled facing the substrate 10 and the substrate 10. Preferably, for the surface of the substrate 10 with a preset solder resist layer 11, there is also a gap between the lower surface of the devices 22 to be filled and the solder resist layer 11.

[0066] Please also refer to Figure 3 and Figure 4Each of the devices to be filled 22 also has a third end 22a that is closest to the first edge 15 of the substrate 10 and a fourth end 22b that is furthest from the first edge 15 of the substrate 10. The third end 22a is located at a third distance L3 from the first edge 15 of the substrate 10, and the fourth end 22b of the device to be filled 22 is located at a fourth distance L4 from the first edge 15 of the substrate 10.

[0067] Please refer to Figure 4 In the first embodiment, the third distance L3 and the fourth distance L4 of any of the devices to be filled 22 are not simultaneously located between the first distance L1 and the second distance L2, so that the device to be filled 22 will not be completely covered when the separator film 30 is applied, so that the second gap can communicate with the outside, which is convenient for filling the second gap in the subsequent molding process, thereby improving the reliability of the device.

[0068] Preferably, the horizontal distance between the fourth end and the second end is not less than 150 μm, or the horizontal distance between the third end and the first end is not less than 150 μm. When the filter chip 21 and the device to be filled 22 are at this horizontal distance, even if the device to be filled 22 is partially covered after coating, its second gap will not be completely closed, and it can still be filled.

[0069] In the first embodiment, two filter chips 21 and three devices to be filled 22 are provided on the substrate 10. The filter chip 21 has a first end 21a closest to the right edge of the substrate 10 and a second end 21b farthest from the right edge of the substrate 10. The first end 21a and the second end 21b are respectively located at a first distance L1 and a second distance L2 from the right edge of the substrate 10. The device to be filled 22 has a third end 22a closest to the right edge of the substrate 10 and a fourth end 22b farthest from the right edge of the substrate 10. The third end 22a and the fourth end 22b are respectively located at a third distance L3 and a fourth distance L4 from the right edge of the substrate 10. In this embodiment, the fourth distance L4 is greater than the third distance L3, greater than the second distance L2, and greater than the first distance L1.

[0070] Please also refer to Figures 4 to 6 In the first embodiment, with Figure 5Taking the illustrated filter RF module packaging structure as an example, it includes two semiconductor device modules 20 that are laterally adjacent and mirror-distributed on a substrate 10. The top view of this embodiment is directed towards the first surface 10a perpendicular to the substrate 10. The filter chip 21 and the device to be filled 22 on the left semiconductor device module 20 are distributed horizontally, while the corresponding chip and device on the right semiconductor device module 20 are mirror-distributed along the longitudinal centerline. This arrangement allows the filter chips 21 on the two laterally adjacent RF units 21 to be close together, forming an adjacent filter chip 21 area. Furthermore, subsequent coating processes only require continuous longitudinal coating of the concentrated filter chip 21 area. Figure 6 The dotted line shows the coating area of ​​the isolation film 30, thereby saving coating area (only covering part of the filter chip 21) and reducing costs. Preferably, based on the above structure, considering the ease of implementation and optimal cost, the isolation film can be a strip-shaped isolation film. In the packaging structure of a filter RF module containing many RF units, several strip-shaped isolation films can be used for coating. Moreover, only the filter chips 21 are coated, while the device to be filled 22 is not coated. In this way, in the subsequent molding process, the second gap formed between the lower surface of the device to be filled 22 and the substrate 10 can be filled together. This avoids the product from bursting and breaking due to the internal gas expansion caused by the cavity at the bottom of the device to be filled 22 under incomplete vacuum conditions after multiple high-temperature processes, which would affect the reliability of the module.

[0071] As a variation, please refer to Figure 7 In the modified example shown, the first edge 15 of the corresponding substrate 10 is the lower edge, that is, it is mirrored along the lateral direction. Thus, the area of ​​the filter chip 21 along the lateral center line can also be continuously coated.

[0072] It should be noted that the radio frequency unit described in this invention is a single structure cut from a filter radio frequency module packaging structure after being packaged with a plastic encapsulation layer; therefore, for ease of understanding, this invention provides the following, but not limited to, embodiments as explanations of the arrangement of the filter chip 21 and the device to be filled 22 provided by this invention to demonstrate the superiority of this invention.

[0073] In detail, the semiconductor device modules 20 of the present invention can be arranged in various ways on the substrate 10, as follows:

[0074] Figure 8 The diagram shown is a top view of a radio frequency unit according to a second embodiment of the present invention.

[0075] refer to Figure 8 and Figure 9 In this second embodiment, the filter chip 21 has a first end 21a and a second end 21b; the device to be filled 22 has a third end 22a and a fourth end 22b. The first end 21a, the second end 21b, the third end 22a and the fourth end 22b are respectively located at a first distance L1, a second distance L2, a third distance L3 and a fourth distance L4 from the right edge of the substrate 10; the fourth distance L4 is greater than the second distance L2, greater than the third distance L3 and greater than the first distance L1.

[0076] Figure 10 The diagram shown is a top view of a radio frequency unit according to a third embodiment of the present invention.

[0077] refer to Figure 10 and Figure 11 In this third embodiment, the difference from the first embodiment is that the fourth distance L4 is greater than the second distance L2, which is greater than the first distance L1, which is greater than the third distance L3.

[0078] Figure 12 The diagram shown is a top view of a radio frequency unit according to a fourth embodiment of the present invention.

[0079] refer to Figure 12 and Figure 13 In this fourth embodiment, the difference from the first embodiment is that the second distance L2 is greater than the fourth distance L4, which is greater than the first distance L1, which is greater than the third distance L3.

[0080] Figure 14 The diagram shown is a top view of a radio frequency unit according to the fifth embodiment of the present invention;

[0081] refer to Figures 14 to 16 In this fifth embodiment, the difference from the first embodiment is that the second distance L2 is greater than the first distance L1, the fourth distance L4 is greater than the third distance L3. It can be found that in this embodiment, the filter chip 21 is located between the two devices to be filled 22. Therefore, it also adopts concentrated coating for the filter chip 21 area. Compared with the previous embodiment, it can also achieve the effect of saving coating area and reducing cost.

[0082] As a variation, please refer to Figure 17 In the modified example shown, the first edge 15 of the corresponding substrate 10 is the lower edge, that is, it is mirrored along the transverse centerline, thereby realizing the continuous coating of the transverse filter chip 21.

[0083] The separator 30 can be made of polymer films such as epoxy resin, polyimide, thermoplastic resin, or thermosetting resin, for example... Figure 2As shown, the isolation film 30 serves to isolate, protect, and fix the filter chip 21. The entire surface of the isolation film 30 is pressed onto the first surface 10a of the substrate 10 and the filter chip 21, forming a closed cavity 14 between the filter chip 21, the substrate 10, and the isolation film 40. As a preferred embodiment, as... Figure 18 As shown, the isolation film 30 can extend to cover at least one side of the adjacent device 22 to be filled, which is near the filter chip 21. This configuration allows for a more relaxed requirement for the dimensional accuracy of the isolation film 30. It can extend to cover the device 22 to be filled while also covering the filter chip 21, and selectively or adaptively cover some sides of the adjacent device 22 to be filled, thereby reducing the required precision of the isolation film 30 and consequently reducing production costs. It should be noted that the isolation film 30 can extend to cover multiple sides of the adjacent device 22 to be filled, while retaining at least a portion of the gap for the molding compound 40 to fill the second gap, thereby improving the reliability of the module. Preferably, the isolation film 30 is a plurality of strip-shaped isolation films 30. Combined with the arrangement of the semiconductor device modules 20 on the filter RF module packaging structure provided by this invention, the process flow can be significantly simplified, and costs can be greatly reduced.

[0084] In a preferred embodiment, the height of the enclosed cavity 14 (i.e., the distance between the lower surface of the filter chip 21 and the upper surface of the solder mask layer 11) is above 10 μm and below 30 μm, and the gap between the device to be filled 22 and the solder mask layer 11 (i.e., the distance between the lower surface of the device to be filled 22 and the upper surface of the solder mask layer 11) can be above 10 μm and below 30 μm. This setting ensures that the isolation membrane 30 only fills the gap between the edge of the filter chip 21 and the device to be filled 22 and the solder mask layer 11, and does not flow excessively into the interior of the enclosed cavity / gap. This achieves a good sealing effect and avoids affecting the performance of the filter chip 21 and the device to be filled 22. However, if the gap height is too small, the distance between the solder mask layer 11 and the interdigital transducer 211 will be small, which will affect the signal transmission. Preferably, the height of the enclosed cavity 14 is consistent with the gap height between the device to be filled 22 and the solder mask layer 11, which facilitates the integrated processing of the entire RF module, simplifies the process flow, and improves production efficiency.

[0085] A molding layer 40 is disposed on the substrate 10, which covers the isolation film 30 and the device to be filled 22 that is not covered by the isolation film 30. Considering that the isolation film 30 is relatively thin and its protective ability for the components is relatively weak, the surface covered by the isolation film 30 and the surface of the device to be filled 22 that is not covered by the isolation film 30 are molded by Compression Molding to form the molding layer 40, which provides better electrical protection for the filter chip 21 and the device to be filled 22.

[0086] It is worth noting that, in this embodiment, since the device to be filled 22 is not completely sealed and isolated by the isolation film 30, the molding process can fill the second gap below the device to be filled 22 at the same time, so that the bottom surface of the device to be filled 22 and the substrate 10 are filled with molding material, so as to avoid affecting the reliability of the module due to the cavity at the bottom of the device to be filled 22.

[0087] A method for fabricating a radio frequency unit according to the first embodiment of the present invention is provided, comprising the following steps:

[0088] Step 1, as follows Figure 19 As shown in (a), a substrate 10 and a plurality of semiconductor device modules 20 are provided, formed by RDL wiring layer lamination. A solder resist layer 11 and a plurality of semiconductor device modules 20 (schematically shown as two in this embodiment) are disposed on the first surface 10a of the substrate 10. Each semiconductor device module 20 includes a filter chip 21 and a device to be filled 22 disposed on the first surface 10a of the substrate 10. The filter chip 21 and the device to be filled 22 contained in the two semiconductor device modules 20 are mirror images of each other. That is, in this embodiment, the filter chip 21 and the device to be filled 22 of the two semiconductor device modules 20 are symmetrically arranged with reference to the longitudinal centerline. Figure 19 As shown in (b), the filter chips 21 and the devices to be filled 22 are flip-chip mounted on the substrate 10 using surface mount technology. The first electrode 212 on the filter chip 21 and the second electrode 221 on the device to be filled 22 are respectively connected to the first electrode region 12 and the second electrode region 13. This flip-chip process is beneficial for increasing the assembly density of the RF module, reducing the size and weight of electronic products, and is easy to automate, thereby improving production efficiency and reducing costs.

[0089] Step 2, as follows Figure 20 As shown in (c), the filter chip 21 is covered by the isolation film 40 by vacuum pressing, so that the isolation film 40 is well attached to the substrate 10, the surface and sidewall of the filter chip 21 and is not easy to fall off. Based on this, the first gap formed between the lower surface of the filter chip 21 and the substrate 10 is closed to form a closed cavity 14.

[0090] Step 3, as follows Figure 20 As shown in (d), the surface covered with the isolation film 30 and the surface of the device to be filled 22 without the isolation film 30 are encapsulated by Compression Molding to form a molding layer 40, thereby protecting all components located on the first surface 10a. Since the isolation film 30 only covers the filter chip area 21a, the molding material can fill the second gap between the lower surface of the device to be filled and the substrate, thereby improving the reliability of the device to be filled 22.

[0091] Step 4: After forming the molding layer 40, the filter RF module package structure obtained in step 3) is cut to form the following... Figure 1 The single radio frequency unit shown.

[0092] One embodiment of the present invention provides a communication device having the radio frequency unit described in the above embodiments. By using the radio frequency unit, the damage to the chip during packaging is reduced, the process cost is reduced, and the product reliability and production efficiency are improved.

[0093] Furthermore, those skilled in the art should understand that although many problems exist in the prior art, each embodiment or technical solution of the present invention can be improved in only one or a few aspects, without necessarily solving all the technical problems listed in the prior art or the background art simultaneously. Those skilled in the art should understand that any content not mentioned in a claim should not be construed as a limitation on that claim.

[0094] Although this document frequently uses terms such as substrate, first surface, second surface, solder mask layer, first electrode region, second electrode region, enclosed cavity, semiconductor device module, filter chip, first terminal, second terminal, interdigital transducer, first electrode, device to be filled, third terminal, fourth terminal, second electrode, isolation film, and molding compound, the possibility of using other terms is not excluded. The use of these terms is merely for the convenience of describing and explaining the essence of the invention; interpreting them as any additional limitation would contradict the spirit of the invention. The terms "first," "second," etc. (if present) in the specification, claims, and accompanying drawings of the embodiments of the invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0095] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A radio frequency unit, characterized by The application relates to a radio frequency unit. The radio frequency unit comprises: a substrate having a first surface and an opposite second surface; a semiconductor device module arranged on the first surface of the substrate, the semiconductor device module comprising a plurality of filter chips and one or more to-be-filled devices; the filter chips have a lower surface facing the substrate, and a first gap is formed between the lower surface of the filter chips and the first surface of the substrate; among the plurality of filter chips, a first end closest to a first edge of the substrate and a second end farthest from the first edge of the substrate are provided, the first end is arranged at a first distance from the first edge of the substrate, and the second end is arranged at a second distance from the first edge of the substrate; the to-be-filled devices have a lower surface facing the substrate, and a second gap is formed between the lower surface of the to-be-filled devices and the first surface of the substrate; any to-be-filled device has a third end closest to the first edge of the substrate and a fourth end farthest from the first edge of the substrate, the third end is arranged at a third distance from the first edge of the substrate, and the fourth end is arranged at a fourth distance from the first edge of the substrate; the third distance and the fourth distance of any to-be-filled device are not simultaneously between the first distance and the second distance; 2. The radio unit of claim 1, wherein: an isolation film arranged on the substrate, the isolation film covering the filter chips so that the first gap forms a closed cavity, and the isolation film covers at most three sides of the to-be-filled devices; the isolation film is a strip-shaped isolation film.

3. The radio unit of claim 1, wherein: The horizontal distance between the fourth end and the second end is not less than 150 mu m, or the horizontal distance between the third end and the first end is not less than 150 mu m. The fourth distance is greater than the third distance, which is greater than the second distance, which is greater than the first distance; or The fourth distance is greater than the second distance, which is greater than the third distance, which is greater than the first distance; or The fourth distance is greater than the second distance, which is greater than the first distance, which is greater than the third distance; or The second distance is greater than the fourth distance, which is greater than the first distance, which is greater than the third distance; or 4. The radio unit of claim 1, wherein: The second distance is greater than the first distance, which is greater than the fourth distance, which is greater than the third distance.

5. The radio unit of claim 1, wherein: The to-be-filled devices comprise one or more of a power amplifier, a low-noise amplifier or a switch.

6. The radio unit of claim 1, wherein: The lower surfaces of the filter chips and the to-be-filled devices are each provided with an electrode; the first surface of the substrate is provided with an electrode area connected with the electrodes of the filter chips and the electrodes of the to-be-filled devices respectively, and the first surface of the substrate is provided with a solder mask layer located around the first electrode area and the second electrode area.

7. The radio unit of claim 1, wherein: The radio frequency unit further comprises a plastic sealing layer arranged on the substrate, the plastic sealing layer covering the isolation film and the to-be-filled devices not covered by the isolation film, and filling the second gap.

8. The radio unit of claim 7, characterized in that: The radio frequency unit comprises a plurality of filter chips, and the plurality of filter chips are arranged in the same orientation.

9. A method of manufacturing a radio frequency unit, characterized by The to-be-filled devices are arranged in the same orientation as the filter chips. The application further relates to a method for manufacturing a radio frequency unit. 1) A plurality of semiconductor device modules as claimed in any one of claims 1 to 8 are provided on a substrate having a first surface and an opposite second surface, and electrode regions and solder resist regions around the electrode regions are provided on the first surface of the substrate; the plurality of semiconductor device modules are arranged on the first surface of the substrate and connected to the corresponding electrode regions respectively; the plurality of semiconductor device modules are arranged in a matrix, and adjacent semiconductor device modules are arranged in mirror image in the longitudinal or transverse direction; 2) An isolation film is attached on the first surface of the substrate, and the isolation film covers the filter chip, so that the first gap forms a closed cavity; and the isolation film covers at most three sides of the device to be filled; 3) A plastic encapsulation layer is formed, which covers the isolation film and the device to be filled which is not covered by the isolation film, and fills the second gap; 4) The product obtained in step 3) is cut to obtain independent radio frequency units.

10. The method of manufacturing a radio frequency unit according to claim 9, characterized in that: The isolation film is a plurality of strip-shaped isolation films.

11. A communication device, characterized by A radio frequency unit as claimed in any one of claims 1 to 8 is provided.

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