Cavity filter system-in-package module, electronic product and preparation method

Abstract

The application discloses a cavity filter system-in-package module, an electronic product and a packaging method. The cavity filter system-in-package module comprises a substrate, a first flip chip, a second flip device, a film layer and plastic packaging material. A groove is formed in the substrate, and the groove extends from the upper surface of the substrate to the inside of the substrate until the layer where the second layer pattern is located or below. The first flip chip is attached or welded in the groove. The second flip device is attached or welded on the upper surface of the substrate. A solder resist layer is arranged around the first flip chip and the second flip device. The surface of the first flip chip and the solder resist layer forms a continuous film layer. The film layer on the surface of the second flip device and the solder resist layer is disconnected. The application can improve the reliability of the module, and the process is simple and the cost is low.

Description

Technical Field

[0001] This invention relates to a cavity filter system-in-package module, as well as electronic products containing the cavity filter system-in-package module, and a method for preparing the cavity filter system-in-package module, belonging to the field of semiconductor packaging technology. Background Technology

[0002] In wireless networks, when data needs to be transmitted, user equipment (UE) must continuously listen to the physical downlink control channel (PHC) and send and receive data according to the instruction messages sent by the network side. This results in significant power consumption and data transmission latency for the UE. Therefore, the 3GPP protocol introduced the Discontinuous Reception (DRX) energy-saving strategy in LTE systems, defined at the physical layer media access control. Consequently, the radio frequency front-end used in 5G includes a diversity reception path, which is essentially a reception path used to assist the main receiver in signal reception.

[0003] Traditional diversity receiver modules include multiple filter chips, which are typically encapsulated with a film to isolate the outer molding compound and ensure a cavity at the bottom of the filter. However, the bottoms of other chips or devices within the module cannot be properly filled due to the film, which can easily lead to solder bridging and short circuits. At the same time, the reliability of non-filter chips and devices cannot be guaranteed due to insufficient molding compound filling.

[0004] Chinese patent application No. 202110468684.8 discloses a filter system-level hybrid packaging module and packaging method. The module includes two filters respectively disposed in a first space and a second space, and the first space and the second space are separated by a metal coating. This is used to solve the problems of difficulty in integrating and packaging different filters and mutual interference between different types of filters working together in the system-level packaging module. Summary of the Invention

[0005] The primary technical problem to be solved by this invention is to provide a cavity filter system-in-package module.

[0006] Another technical problem to be solved by the present invention is to provide a method for preparing a cavity filter system-level packaging module.

[0007] Another technical problem to be solved by the present invention is to provide an electronic product including a cavity filter system-in-package module.

[0008] To achieve the above-mentioned technical objectives, the present invention adopts the following technical solution:

[0009] According to a first aspect of the present invention, a cavity filter system-in-package module is provided, including a substrate, a first flip chip, a second flip device, a film layer, and a molding compound;

[0010] The substrate has a groove that extends from the upper surface of the substrate into the interior of the substrate until the second pattern layer or below is located.

[0011] The first flip chip is mounted or soldered into the groove;

[0012] The second flip-chip device is mounted or soldered to the upper surface of the substrate;

[0013] A solder resist layer is disposed around the first flip chip and the second flip device;

[0014] The first flip chip forms a continuous film layer with the surface of the solder resist layer; the second flip device has a disconnected film layer with the surface of the solder resist layer.

[0015] Preferably, a gap is formed between the solder resist layer and the first flip chip, and the gap is smaller than the size of the filler in the molding compound.

[0016] Preferably, a distance is formed between the second flip device and the solder mask layer, the distance being greater than the gap.

[0017] Preferably, the distance is adjusted according to the height of the bump of the second flip device, the size of the opening in the solder mask layer, and the thickness of the solder mask layer.

[0018] Preferably, the distance reaches 20 μm or more.

[0019] Preferably, the cavity filter system-in-package module further includes a colloid for filling the gap.

[0020] According to a second aspect of the present invention, a method for fabricating a cavity filter system-in-package module is provided, comprising the following steps:

[0021] S11: Prepare a substrate with a groove extending from the upper surface of the substrate into the interior of the substrate until the second pattern layer or below.

[0022] S12: Fabricate the first flip chip and the second flip device;

[0023] S13: Connect the bumps of the first flip chip to the second conductive line in the groove to fix the first flip chip into the groove;

[0024] S14: Solder the second flip device to the second pad;

[0025] S15: A solder resist layer is formed on the upper surface of the substrate, the solder resist layer surrounding the first flip chip and the second flip device;

[0026] S16: A film layer is applied to the solder resist layer, the first flip chip, and the second flip device through a film coating process;

[0027] S17: Use a molding process to form a molding material in the film layer.

[0028] According to a third aspect of the present invention, a method for fabricating a cavity filter system-in-package module is provided, comprising the following steps:

[0029] S21: Prepare a substrate with a groove extending from the upper surface of the substrate into the interior of the substrate until the second pattern layer or below.

[0030] S22: Fabricate the first flip chip and the second flip device;

[0031] S23: Connect the bumps of the first flip chip to the second conductive line in the groove to fix the first flip chip into the groove;

[0032] S24: Solder the second flip device to the second pad;

[0033] S25: A solder resist layer is formed on the upper surface of the substrate, the solder resist layer surrounding the first flip chip and the second flip device;

[0034] S26: Using a dispensing process, an adhesive is formed between the first flip chip and the solder mask layer surrounding the first flip chip;

[0035] S27: Use a molding process to form a molding material.

[0036] In step S27, the film layer is broken by the pressure of the molding material.

[0037] According to a fourth aspect of the present invention, an electronic product is provided, which includes a cavity filter system-in-package module as described above.

[0038] Compared with the prior art, the present invention has the following technical effects: the filter chip is soldered in a recessed cavity formed by the substrate solder resist layer and polypropylene (PP), and the non-filter chip and passive components are normally soldered on the surface layer pads of the substrate. Then, selective filling with molding compound can ensure that a cavity can be formed at the bottom of the filter in the module, and the bottom of the non-filter chip and passive components can be well filled, avoiding solder bridging and improving the reliability of the module. Attached Figure Description

[0039] Figure 1 This is a schematic diagram of the structure of the cavity filter system-in-package module in the first embodiment of the present invention;

[0040] Figures 2A(a) to 2A(i) are schematic diagrams of the fabrication process of the substrate of the cavity filter system-in-package module in the second embodiment of the present invention;

[0041] Figures 2B(a) to 2B(m) This is a schematic diagram of the fabrication process of the substrate of the cavity filter system-in-package module in the second embodiment of the present invention;

[0042] Figure 2C This is a schematic diagram of the coating process in the fabrication method of the cavity filter system-level packaging module in the second embodiment of the present invention;

[0043] Figure 2D This is a schematic diagram of the molding process in the fabrication method of the cavity filter system-level packaging module in the second embodiment of the present invention;

[0044] Figure 2E for Figure 2C A top view of the substrate after removing the first flip chip and the second flip device before the intermediate coating;

[0045] Figure 3A This is a schematic diagram of the dispensing process in the fabrication method of the cavity filter system-in-package module in the third embodiment of the present invention;

[0046] Figure 3B This is a schematic diagram of the molding process in the fabrication method of the cavity filter system-level packaging module in the third embodiment of the present invention. Detailed Implementation

[0047] The technical content of the present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0048] (First Embodiment)

[0049] like Figure 1 As shown, the cavity filter system-in-package module provided in the first embodiment of the present invention includes a substrate 1, a first flip chip 2, a second flip device 3, a film layer 6, and a molding compound 7. Both the first flip chip 2 and the second flip device 3 are flip chips, meaning the chip's bumps face downwards and are connected to the substrate, carrier, or circuit board. The first flip chip 2 is a cavity filter chip, such as a surface acoustic wave (SAW) filter or a bulk acoustic wave (BAW) filter chip, but this does not constitute a limitation of the present invention. Furthermore, the second flip device can be a flip chip or a surface mount component; a flip chip will be used as an example for explanation.

[0050] Here, substrate 1 can be any carrier with multiple wiring layers, such as a circuit board, ceramic substrate, FR-4 epoxy fiberglass cloth substrate, or other organic or inorganic substrate. In this embodiment, a PP substrate is used as an example. PP substrate, also known as a prepreg, is typically composed of fiberglass cloth, resin, dicyandiamide, accelerator, solvent, and additive.

[0051] In this embodiment, a three-layer substrate is used as an example for illustration. However, those skilled in the art will understand that any substrate with three or more layers can implement the present invention.

[0052] The substrate 1 includes a first pattern 101, a second pattern 102, second pads 12, and a barrier layer 4. The substrate may also include a third pattern 103, the number of which is not limited, but only needs to be greater than two. The first pattern 101 and the second pads 12 are formed on the upper surface 100 of the substrate 1 in the same process using electroplating or etching. In other words, multiple second pads 12 are formed in copper in the non-grooved area of ​​the front side 100 of the substrate 1 for connecting the second flip-chip 3. The first flip chip 2 and the second flip-chip 3 are soldered to the upper surface 100 of the substrate 1. A barrier layer 4 is formed on the upper surface 100 around the outer periphery of the first flip chip 2 and the second flip-chip 3.

[0053] Furthermore, the substrate 1 also includes a groove 111. The groove 111 extends from the solder mask layer 4 into the interior of the substrate until it reaches the surface where the second pattern 102 is located. That is, the bottom surface of the groove 111 (i.e., the surface inside the substrate) is coplanar with the second pattern 102 (ignoring the thickness of the metal itself in the second pattern). In other words, the depth of the groove 111 is equal to the distance between the first pattern 101 and the second pattern 102. On the bottom surface of the groove 111, a second conductive line 11 made of copper is formed within the groove for connecting the first flip chip 2.

[0054] The first flip chip 2 includes a chip body 21 and bumps 22. The chip body 21 has a lower surface 211 and a side surface 212. Bumps 22 are formed on the lower surface 211 of the chip body 21. The bumps 22 can be copper pillars or solder balls, etc.

[0055] The first flip chip 2 is mounted in the recess 111 such that the lower surface 211 of the chip body 21 is lower than the upper surface of the solder resist layer 4 of the substrate 1. Furthermore, the distance between the lower surface 211 and the solder resist layer 4 satisfies the condition that the distance between the side surface 212 of the chip body 1 and the solder resist layer 4 is small enough that large-sized filler particles contained in the molding compound cannot flow between the solder resist layer 4 and the side surface 212. In this way, the large-sized filler blocks the gap 9 between the solder resist layer 4 and the side surface 212, keeping the molding compound outside the recess 111.

[0056] In this embodiment, the second conductive line 11 in the groove is part of the second layer pattern 102, which is the second layer pattern 102 exposed in the groove.

[0057] To ensure that the distance between the solder resist layer 4 and the lower surface 211 meets the aforementioned conditions, the size of the bump 22 must match the depth of the groove 111, so that the lower surface 211 is lower than the surface of the solder resist layer 4, making it difficult for the molding compound to flow through the gap 9.

[0058] The film layer 6 is made of conventional thermoplastic material and is applied to the upper surfaces of the solder resist layer 4, the first flip chip 2, and the second flip device 3 using a conventional vacuum coating process. A continuous film layer 6 is formed between the chip body 21 of the first flip chip 2 and the solder resist layer 4 surrounding the chip body 21, and the film layer 6 covers (or seals) the gap 9. Therefore, the molding compound 7 cannot enter the gap 9, and thus cannot enter the cavity 111. By designing the film layer 6 to match the gap 9, it is possible to ensure that the film layer 6 can seal the gap without entering it (and even less so, without flowing through the gap into the cavity); it is also possible to ensure that the film layer 6 covering the first flip chip and the solder resist layer 4 surrounding the first flip chip can withstand molding and is not broken by the molding compound.

[0059] However, there is no continuous film layer 6 between the second flip device 3 and the solder mask layer 4 surrounding the second flip device 3. For example... Figure 1 As shown, the film layer between the second flip device 3 and the nearby solder resist layer 4 is broken. By designing the distance between the second flip device 3 and the nearby solder resist layer 4, or by changing the film layer thickness or material, this invention can simultaneously achieve the following: the film layer 6 covering the first flip chip and the solder resist layer 4 surrounding the first flip chip remains unbroken; while the film layer 6 covering the second flip device and the solder resist layer 4 surrounding the second flip device is broken or partially broken.

[0060] <Second Embodiment>

[0061] As shown in Figures 2A and 2B, the second embodiment of the present invention provides a method for fabricating a cavity filter system-level packaging module, including the following steps:

[0062] S11: Prepare a substrate 1 with a groove 111, which extends from the solder resist layer 4 of the substrate 1 into the substrate until the layer containing the second pattern 102 or below.

[0063] As shown in Figures 2A(a) to 2A(i), the substrate 1 has a recess 111 that sinks to the second layer pattern 102 (in this embodiment, the second conductive line is used as an example) or the layer where the third layer pattern is located.

[0064] In this embodiment, the groove 111 is formed by electroplating copper on the inner substrate and then etching to remove the copper block. Specifically, as shown in Figure 2A(a), a second conductive line (second layer pattern 102) of copper is formed on an inner substrate (e.g., PP material); then a film is laminated and exposed and developed (as shown in Figures 2A(b) and 2A(c)) to expose the conductive line; copper pillars are formed on the exposed second conductive line using electroplating processes (as shown in Figure 2A(d)); the residual film is removed using a stripping process (as shown in Figure 2A(e)); a resin film is then laminated (as shown in Figure 2A(f)) and the copper pillars are exposed using a thinning process (as shown in Figure 2A(g)); then a film is laminated and exposed and developed (as shown in Figures 2A(h) and 2A(i)) to expose the copper pillars located at the groove positions (groove position copper pillars); then an etching process (as shown in Figure 2A(j)) is used to remove the exposed groove position copper pillars, so that the second conductive line in the groove below the groove position copper pillar is exposed, that is, the second conductive line (i.e., the second layer pattern 102) is exposed in the groove. Then, the film is removed (as shown in Figure 2A(k)), and finally, the first conductive line (i.e., the first layer pattern 101) is formed on the resin film.

[0065] like Figures 2B(a) to 2B(b)As shown, substrate 1 has a recess 111 that sinks into the second layer pattern 102, formed by pre-pressing a copper block on the inner layer substrate and then etching to remove the copper block. As shown in FIG2B(a), a copper second conductive line (second layer pattern 102) is formed on the inner layer substrate (e.g., PP material); then a film is applied and exposed and developed (as shown in FIG2B(b) and FIG2B(c)), exposing the second conductive line (102B) but not exposing the second conductive line (102A) in the recess; copper pillars are formed on the exposed second conductive line (102B) using electroplating processes (as shown in FIG2B(d)); the residual film is removed using a stripping process (as shown in FIG2B(e)), so that all the second conductive lines (including 102A and 102B) are exposed. Next, a pre-fabricated copper block is bonded to the second conductive line (102A) within the groove (as shown in Figure 2B(f)). Then, a resin film is laminated (as shown in Figure 2B(g)), and a thinning process is used to expose the copper block (as shown in Figure 2B(h)). Next, another film is applied and exposed and developed to expose the copper block located at the groove position (groove position copper block) (as shown in Figures 2B(i) and 2B(g)). Then, an etching process is used to remove the exposed groove position copper block, exposing the second conductive line (102A) within the groove below the groove position copper block, thus exposing the second layer pattern 102 within the groove (as shown in Figure 2B(k)). Finally, the film is stripped, forming the first copper layer (i.e., the first layer pattern 101) on the resin film.

[0066] S12: Fabricate the first flip chip 2 and the second flip device 3.

[0067] These are standard procedures and will not be elaborated upon here.

[0068] S13: Connect the bump 22 of the first flip chip 2 to the second conductive line 11 in the groove, and fix the first flip chip 2 into the groove 111.

[0069] As shown in Figure 3, since the groove 111 is coplanar with the second layer pattern 102, the first flip chip 2 is fixed to the second layer of the substrate and is not on the upper surface of the substrate. However, the lower surface 211 of the first flip chip 2 is higher than the upper surface of the substrate (i.e., the two are not in contact).

[0070] S14: Solder the second flip device 3 to the second pad 12.

[0071] like Figure 2C As shown, since the second pad 12 is coplanar with the first layer pattern 101, the second flip device 3 is fixed on the upper surface of the substrate.

[0072] S15: A solder resist layer 4 is formed on the upper surface of the substrate 1, and the solder resist layer 4 surrounds the first flip chip 2 and the second flip device 3.

[0073] Combination Figure 2C and Figure 2E As shown, the solder mask layer 4 surrounds the projection area of ​​the first flip chip 2 and the second flip device 3 on the substrate 1. Figure 2E It is a top view of the substrate with the first flip chip and the second flip device removed, clearly showing that the solder mask 4 is outside the projection area of ​​the first flip chip and the second flip device, that is, the solder mask 4 does not extend below the lower surface of the first flip chip.

[0074] like Figure 2C As shown, a gap 9 is formed between the side 212 of the first flip chip and the solder mask layer 4. The size of the gap 9 (the dimension in the horizontal direction) satisfies the aforementioned conditions so that the gap 9 can be blocked by a large-sized filler, thereby keeping the molding compound outside the groove 111 and protecting the first flip chip 2 from contamination by the molding compound.

[0075] Simultaneously, in the horizontal direction, the distance S between the solder mask layer 4 and the second flip device 3 is greater than the size L of the gap 9, for example, S ≥ 1.2~5L. The distance S between the second flip device and the substrate can be adjusted according to factors such as the height of the bumps of the second flip device, the size of the opening in the solder mask layer, and the thickness of the solder mask layer. For example, the size L of the gap 9 should be controlled to be less than 15µm; the distance S needs to be controlled to be greater than 15µm. Preferably, the distance S reaches 20µm, or even 30µm or more, to ensure that the film layer 6 can break during the molding process. Preferably, the gap L is less than or equal to the filler size to ensure that the filler does not enter the gap 9.

[0076] It is understandable that step S15 can be designed after step S12 and before step S13. That is, the solder resist layer is applied first, and then the first flip chip 2 and the second flip device 3 are fixed.

[0077] S16: Using a coating process, a film layer 6 (e.g., ...) is applied to the solder resist layer 4, the first flip chip 2, and the second flip device 3. Figure 2C (As shown).

[0078] Because the gap 9 is very small, it can provide sufficient support for the film layer 6. Therefore, the film layer 6 can block the gap 9, preventing the molding material from entering the gap.

[0079] S17: A molding compound 7 is formed on top of the film layer 6 using a molding process.

[0080] like Figure 2DAs shown, due to the pressure caused by the molding compound, the film layer 6 surrounding the second flip device 3 is broken during the molding process; the film layer 6 surrounding the first flip chip 2, though broken during the molding process, remains continuous and does not break. This is because the distance S between the solder resist layer 4 and the second flip device 3 is greater than the gap L between the solder resist layer 4 and the first flip chip 2. A larger distance S results in a longer length of the film layer 6 (in a suspended state) that is not supported by the solder resist layer 4. Even under the same molding pressure, the supporting force on the film layer 6 between the solder resist layer 4 and the second flip device 3 is less than the supporting force on the film layer 6 between the solder resist layer 4 and the first flip chip 2. Therefore, the film layer 6 between the solder resist layer 4 and the second flip device 3 is more prone to breakage under pressure.

[0081] Therefore, in this step, we obtain the following: Figure 2D The film layer 6 shown is continuous around the first flip chip 2 and breaks around the second flip device 3. Furthermore, the molding compound enters between the second flip device 3 and the upper surface 100 of the substrate 1; however, it does not enter the groove 111 below the first flip chip.

[0082] Even better, even if the film layer 6 surrounding the first flip chip 2 breaks, the plastic material cannot enter the groove 111 because the gap 9 is small enough that the filler is blocked in the gap 9.

[0083] <Third Embodiment>

[0084] Unlike the second embodiment, the method for fabricating a cavity filter system-level packaging module provided in this embodiment employs a dispensing process, such as... Figure 3A and Figure 3B As shown, the specific steps include:

[0085] S21: Prepare a substrate 1 with a groove 111, which extends from the upper surface of the substrate 1 into the interior of the substrate until the layer containing the second pattern 102 or below.

[0086] S22: Fabricate the first flip chip 2 and the second flip device 3;

[0087] S23: Connect the bump 22 of the first flip chip 2 to the second conductive line 11 in the groove, and fix the first flip chip 2 into the groove 111.

[0088] S24: Solder the second flip device 3 to the second pad 12.

[0089] S25: A solder resist layer 4 is formed on the upper surface of the substrate 1, and the solder resist layer 4 surrounds the first flip chip 2 and the second flip device 3.

[0090] S26: Using a dispensing process, an adhesive 5 is formed between the first flip chip 2 and the solder mask 4 surrounding the first flip chip 2.

[0091] like Figure 3A As shown, by using a dispensing process, some of the adhesive can enter the gap 9 and form adhesive 5, so as to achieve a seal between the first flip chip 2 and the solder mask layer 4 surrounding the first flip chip 2, preventing the molding compound from entering the groove.

[0092] S27: Using a molding process to form molding material 7.

[0093] like Figure 3B As shown, since the first flip chip 2 and the surrounding solder mask layer 4 are sealed by the colloid 5, the molding compound cannot be poured into the groove below the first flip chip 2 through the gap during the molding process.

[0094] There is no seal between the second flip device 3 and the surrounding solder mask layer 4, so the molding compound can directly enter between the second flip device 3 and the upper surface of the substrate.

[0095] The filler particles in the molding compound 7 are too large to enter and fill the gap 9, thus being isolated from the first flip chip 2; the second flip device 3 and other passive devices maintain a sufficient distance S from the substrate, allowing the molding compound 7 to fill to the bottom.

[0096] <Fourth Embodiment>

[0097] Unlike the first embodiment, in this embodiment, a solder resist layer is formed first, and then the first flip chip 2 and the second flip device 3 are placed; moreover, no film coating or adhesive is required, and only a sufficiently small gap 9 is used to prevent the molding compound from entering the bottom of the first flip chip.

[0098] S31: Prepare a substrate 1 with a groove 111, the groove 111 extending from the upper surface of the substrate 1 into the interior of the substrate until the layer containing the second pattern 102 or below, and form a solder resist layer.

[0099] S32: Fabricate the first flip chip 2 and the second flip device 3;

[0100] S33: Connect the bump 22 of the first flip chip 2 to the second conductive line 11 in the groove, fix the first flip chip 2 into the groove 111, so that the solder mask layer 4 surrounds the first flip chip 2 and forms a gap 9, the size L of the gap 9 is smaller than the size of the filler in the molding compound.

[0101] S34: Solder the second flip device 3 to the second pad 12, so that the solder mask layer 4 surrounds the second flip device 3 and forms a distance S, and S > L;

[0102] S35: A molding process is used to form a molding material 7 using a molding material containing the filler.

[0103] <Fifth Embodiment>

[0104] This invention also provides an electronic product comprising the aforementioned cavity filter system-in-package module. This electronic product can be a wireless communication device, a wearable electronic device, or an electric vehicle, etc.

[0105] In summary, the cavity filter system-in-package module provided by this invention can ensure that a cavity can be formed at the bottom of the filter within the module, while the bottoms of non-filter chips and passive components are well filled, by soldering the filter chip into a recessed cavity formed by the substrate solder resist layer and prepreg, and soldering non-filter chips and passive components normally onto the surface pads of the substrate. Selective filling with molding compound ensures that a cavity can be formed at the bottom of the filter within the module, while the bottoms of non-filter chips and passive components are well filled, preventing solder bridging and improving the reliability of the cavity filter system-in-package module. Furthermore, the manufacturing method is simple, resulting in low cost.

[0106] The cavity filter system-in-package module, electronic product, and manufacturing method provided by this invention have been described in detail above. Any obvious modifications made by those skilled in the art without departing from the essential content of this invention will constitute an infringement of the patent rights of this invention and will incur corresponding legal liability.

Claims

1. A cavity filter system-in-package module, comprising a substrate, a first flip chip, a second flip device, a film layer, and a molding compound, characterized in that: The substrate has a groove that extends from the upper surface of the substrate into the interior of the substrate until the second pattern layer or below is located. The first flip chip is mounted or soldered into the groove; The second flip-chip device is mounted or soldered onto the upper surface of the substrate; A solder resist layer is disposed around the first flip chip and the second flip device; The first flip chip forms a continuous film layer with the surface of the solder resist layer; the second flip device has a disconnected film layer with the surface of the solder resist layer. The lower surface of the first flip chip is lower than the upper surface of the solder mask layer. A gap is formed between the solder mask layer and the side surface of the first flip chip. This gap is smaller than the size of the filler in the molding compound, so that a larger filler can be used to block the gap, thereby keeping the molding compound outside the groove and preventing the first flip chip from being contaminated by the molding compound. The encapsulating material is formed using an encapsulating material having the filler.

2. The cavity filter system-in-package module as described in claim 1, characterized in that: A distance is formed between the second flip device and the solder mask layer, and the distance is greater than the gap.

3. The cavity filter system-in-package module as described in claim 2, characterized in that: The distance is adjusted based on the height of the bumps of the second flip device, the size of the opening in the solder mask, and the thickness of the solder mask.

4. The cavity filter system-in-package module as described in claim 3, characterized in that: The distance reaches more than 30 μm.

5. The cavity filter system-in-package module as described in claim 1, characterized in that... It also includes a colloid that fills the gap.

6. A method for fabricating a cavity filter system-in-package module, characterized in that... Includes the following steps: S11: Prepare a substrate with a groove extending from the upper surface of the substrate into the interior of the substrate until the second pattern layer or below. S12: Fabricate the first flip chip and the second flip device; S13: Connect the bumps of the first flip chip to the second conductive line in the groove to fix the first flip chip into the groove; S14: Solder the second flip device to the second pad; S15: A solder resist layer is formed on the upper surface of the substrate, the solder resist layer surrounding the first flip chip and the second flip device; S16: A film layer is applied to the solder resist layer, the first flip chip, and the second flip device through a film coating process; S17: The molding process is used to form a molding compound using a molding compound containing fillers. A gap is formed between the solder mask layer and the side of the first flip chip. The gap is smaller than the size of the filler in the molding compound, so that the gap is blocked by a large-sized filler, thereby keeping the molding compound outside the groove and protecting the first flip chip from contamination by the molding compound.

7. The method for fabricating a cavity filter system-in-package module as described in claim 6, characterized in that: In step S17, the film layer is broken by the pressure of the molding material.

8. A method for fabricating a cavity filter system-level packaging module, characterized in that... Includes the following steps: S21: Prepare a substrate with a groove extending from the upper surface of the substrate into the interior of the substrate until the second pattern layer or below. S22: Fabricate the first flip chip and the second flip device; S23: Connect the bumps of the first flip chip to the second conductive line in the groove to fix the first flip chip into the groove; S24: Solder the second flip device to the second pad; S25: A solder resist layer is formed on the upper surface of the substrate, the solder resist layer surrounding the first flip chip and the second flip device; S26: Using a dispensing process, an adhesive is formed between the first flip chip and the solder mask layer surrounding the first flip chip; S27: The molding process is used to form a molding compound using a molding compound containing fillers. A gap is formed between the solder mask layer and the side of the first flip chip. The gap is smaller than the size of the filler in the molding compound, so that the gap is blocked by a large-sized filler, thereby keeping the molding compound outside the groove and protecting the first flip chip from contamination by the molding compound.

9. A method for fabricating a cavity filter system-in-package module, characterized in that... Includes the following steps: S31: Prepare a substrate with a groove extending from the upper surface of the substrate into the interior of the substrate to the layer containing the second pattern or below, and form a solder resist layer. S32: Fabricate the first flip chip and the second flip device; S33: Connect the bumps of the first flip chip to the second conductive line in the groove, fix the first flip chip in the groove, and make the solder mask layer surround the first flip chip and form a gap. S34: Solder the second flip device to the second pad, such that the solder mask surrounds the second flip device and forms a distance S, where S > L; S35: A molding process is adopted, in which molding material with filler is used to form molding material. The gap is smaller than the size of the filler in the molding material, so that the gap is blocked by the large-sized filler, thereby keeping the molding material outside the groove, so that the first flip chip is not contaminated by the molding material.

10. An electronic product, characterized in that... It includes the cavity filter system-in-package module as described in any one of claims 1 to 5.

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