Radio frequency device and method of manufacturing the same

Abstract

The present disclosure provides a radio frequency device and a preparation method thereof, wherein the radio frequency device comprises a radio frequency structure and a packaging structure. The radio frequency structure is used to realize the radio frequency function of the radio frequency device; and the packaging structure is covered on the radio frequency structure to realize the packaging of the radio frequency structure, wherein the packaging structure comprises a plurality of external electrodes, each external electrode of the plurality of external electrodes is in contact with the radio frequency structure and is attached to the back surface of the packaging structure away from the radio frequency structure to improve the rigidity of the main body of the packaging structure. Therefore, on the basis of improving the strength of the cavity structure to improve the structural stability of the main body of the packaging structure, better device structure heat dissipation effect can be further realized through the external electrodes.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the field of semiconductor technology, and in particular to a radio frequency device and a preparation method thereof. BACKGROUND

[0002] The existing encapsulation structure of the organic material of the radio frequency device is generally composed of two parts: a wall for supporting and sealing, and a roof for protection and sealing, which are combined to form a closed cavity structure for protecting the radio frequency device. Among them, the electrodes of the radio frequency device are generally arranged inside the chip, and the bumps of the external electrodes are arranged above the device electrodes and connected with the substrate through the bumps to realize the external connection of the electrical signal. SUMMARY

[0003] (I) Technical problems to be solved

[0004] To solve at least one of the technical problems of the existing radio frequency device due to poor structural stability, the present disclosure provides a radio frequency device and a preparation method thereof.

[0005] (II) Technical solutions

[0006] One aspect of the present disclosure provides a radio frequency device, which comprises a radio frequency structure and an encapsulation structure. The radio frequency structure is used to realize the radio frequency function of the radio frequency device; and the encapsulation structure covers the radio frequency structure to realize the encapsulation of the radio frequency structure, wherein the encapsulation structure comprises a plurality of external electrodes, each of the plurality of external electrodes is in contact with the radio frequency structure, and is attached to the back surface of the encapsulation structure away from the radio frequency structure to improve the rigidity of the main body of the encapsulation structure.

[0007] According to an embodiment of the present disclosure, the radio frequency structure comprises a substrate, a functional layer and a plurality of bottom electrodes. The substrate is used to support the radio frequency structure and the encapsulation structure; the functional layer is arranged on the upper surface of the middle region of the substrate and is used to realize the radio frequency function; and the plurality of bottom electrodes are arranged on the upper surface of the substrate around the functional layer along the edge of the upper surface of the substrate.

[0008] According to an embodiment of the present disclosure, the encapsulation structure further comprises a support wall, a roof and a plurality of flip electrodes. The support wall is protruded around the functional layer on the edge of the upper surface of the substrate, and is a closed ring-shaped protruding structure; the roof is the main body of the encapsulation structure, and is arranged corresponding to the area formed by the support wall around the functional layer, forming a closed space between the radio frequency structure and the encapsulation structure, which is used to make the radio frequency function of the functional layer more stable; and the plurality of flip electrodes correspond to the plurality of external electrodes one by one, and are arranged on the back surface of the corresponding external electrode on the roof and in contact with the back surface of the external electrode.

[0009] According to an embodiment of the present disclosure, the edge of the roof facing the front surface of the radio frequency structure is in contact with the end face of the support wall to realize the encapsulation of the radio frequency structure by the roof.

[0010] According to an embodiment of the present disclosure, the packaging structure further comprises a plurality of electrode holes or a plurality of notches. The plurality of electrode holes are arranged on the support wall and correspond to the positions of the plurality of bottom electrodes, so that the bottom electrodes are exposed outside the support wall; the plurality of notches are arranged on the support wall along the outer edge of the support wall and correspond to the positions of the plurality of bottom electrodes, so that the bottom electrodes are exposed outside the support wall.

[0011] According to an embodiment of the present disclosure, each of the plurality of external lead electrodes comprises a main body layer and an external lead layer. The main body layer is attached to the back surface of the top layer film away from the functional layer of the radio frequency structure; the external lead layer is connected with the main body layer to form an integral structure layer; wherein the external lead layer is in contact with the bottom electrode and the substrate of the radio frequency structure in the corresponding electrode hole of the plurality of electrode holes and covers the corresponding bottom electrode; or the external lead layer is in contact with the bottom electrode and the substrate of the radio frequency structure in the corresponding notch of the plurality of notches and covers the corresponding bottom electrode.

[0012] According to an embodiment of the present disclosure, the bottom electrode is not in contact with the support wall, and a spacing gap is arranged on the bottom surface of the electrode hole, which separates the external lead layer from the support wall along the outer edge of the external lead layer.

[0013] According to an embodiment of the present disclosure, the length r1 of the spacing gap and the total circumference r0 of the part of the external lead layer on the bottom surface of the electrode hole satisfy: r1≤r0 / 3.

[0014] According to an embodiment of the present disclosure, the coverage area s1 of the main body layer on the back surface of the top layer film and the contact area s2 between the corresponding flip-chip electrode and the main body layer satisfy: s1≥2s2.

[0015] According to an embodiment of the present disclosure, the materials of the top layer film and the support wall comprise organic materials, wherein the organic materials comprise epoxy resin materials.

[0016] Another aspect of the present disclosure provides a preparation method of the above-mentioned radio frequency device, comprising: forming a radio frequency structure for realizing the radio frequency function of the radio frequency device; covering a packaging structure on the radio frequency structure, comprising: attaching a plurality of external lead electrodes on the back surface of the packaging structure away from the radio frequency structure, and each of the plurality of external lead electrodes is in contact with the radio frequency structure to improve the rigidity of the main body of the packaging structure.

[0017] (III) Beneficial Effects

[0018] This disclosure provides a radio frequency (RF) device and its fabrication method. The RF device includes an RF structure and a packaging structure. The RF structure is used to realize the RF function of the RF device; and the packaging structure covers the RF structure to encapsulate the RF structure. The packaging structure includes multiple external electrodes, each of which is in contact with the RF structure and is attached to the back surface of the packaging structure facing away from the RF structure to improve the rigidity of the packaging structure body. Therefore, based on improving the strength of the cavity structure to improve the structural stability of the packaging structure body, better heat dissipation of the device structure can be achieved further through the external electrodes. Attached Figure Description

[0019] Figure 1 A schematic cross-sectional structural composition diagram of a radio frequency device according to an embodiment of the present disclosure is shown.

[0020] Figure 2 This illustration schematically shows an embodiment of the present disclosure corresponding to the above. Figure 1 The diagram shows the three-dimensional structure of the radio frequency device.

[0021] Figure 3 A schematic cross-sectional structural composition diagram of a radio frequency device according to another embodiment of the present disclosure is shown;

[0022] Figure 4 This illustration schematically shows a corresponding embodiment of the present disclosure to the above. Figure 3 The diagram shows the three-dimensional structure of the radio frequency device.

[0023] Figure 5 This illustration schematically shows a corresponding embodiment of the present disclosure to the above. Figure 4 A top plan view of the external electrode 201-b of the radio frequency device shown;

[0024] Figure 6 A wiring diagram of a three-dimensional structure of a radio frequency device according to another embodiment of the present disclosure is shown schematically;

[0025] Figure 7 This illustration schematically shows an embodiment of the present disclosure corresponding to the above. Figure 1 A flowchart illustrating the fabrication method of the radio frequency device;

[0026] Figure 8 This illustration schematically shows an embodiment of the present disclosure corresponding to the above. Figure 7 A cross-sectional structural composition diagram of a fabrication process of the radio frequency device shown;

[0027] Figure 9 This illustration schematically shows an embodiment of the present disclosure corresponding to the above. Figure 8 A cross-sectional structural composition diagram of another processing step in the fabrication method of the radio frequency device shown;

[0028] Figure 10 schematic diagram of a cross-sectional structure corresponding to the above-mentioned Figure 9 schematic diagram of a cross-sectional structure corresponding to the above-mentioned

[0029] Figure 11 schematic diagram of a cross-sectional structure corresponding to the above-mentioned Figure 9 schematic diagram of a cross-sectional structure corresponding to the above-mentioned

[0030] Figure 12 schematic diagram of a cross-sectional structure corresponding to the above-mentioned Figure 11 schematic diagram of a cross-sectional structure corresponding to the above-mentioned

[0031] Figure 13 schematic diagram of a cross-sectional structure corresponding to the above-mentioned Figure 11 schematic diagram of a cross-sectional structure corresponding to the above-mentioned

[0032] Figure 14 schematic diagram of a cross-sectional structure corresponding to the above-mentioned Figure 13 schematic diagram of a cross-sectional structure corresponding to the above-mentioned

[0033] Figure 15 schematic diagram of a cross-sectional structure corresponding to the above-mentioned Figure 13 schematic diagram of a cross-sectional structure corresponding to the above-mentioned

[0034] Figure 16 schematic diagram of a cross-sectional structure corresponding to the above-mentioned Figure 13 schematic diagram of a cross-sectional structure corresponding to the above-mentioned DETAILED DESCRIPTION

[0035] In order to make the objects, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the drawings and specific embodiments.

[0036] It should be noted that the implementation manners not shown or described in the drawings or the specification are known to those skilled in the art, and are not described in detail. In addition, the definitions of the elements and methods described above are not limited to the specific structures, shapes or manners mentioned in the embodiments, and those skilled in the art can make simple changes or replacements.

[0037] It is also necessary to note that the directional terms mentioned in the embodiments, such as "upper", "lower", "front", "back", "left", "right", etc., are only the directions of the drawings, and are not intended to limit the protection scope of the present disclosure. Throughout the drawings, the same elements are represented by the same or similar reference numerals. When it may cause confusion to the understanding of the present disclosure, the conventional structures or configurations will be omitted.

[0038] And the shape and size of each component in the figure do not reflect the true size and ratio, but only illustrate the content of the embodiments of the present disclosure. In addition, in the claims, any reference symbol located between brackets should not be constructed as a limitation of the claims.

[0039] Furthermore, the word "comprising" does not exclude the presence of elements or steps not listed in the claims. The word "a" or "an" preceding an element does not exclude the presence of more than one such element.

[0040] The ordinal numbers used in the specification and claims, such as "first", "second", "third", etc., are used to modify the corresponding elements, which by themselves do not mean that the element has any ordinal number, nor represent the order or sequence of the manufacturing method of one element and another element. The use of these ordinal numbers is only used to make the element with a certain name distinguishable from another element with the same name.

[0041] Those skilled in the art can understand that the modules in the device in the embodiments can be adaptively changed and arranged in one or more devices different from the embodiments. The modules or units or components in the embodiments can be combined into one module or unit or component, and in addition, they can be divided into multiple sub-modules or sub-units or sub-components. Except that at least some of such features and / or processes or units are mutually exclusive, all features disclosed in the specification (including the accompanying claims, abstract and drawings) and all processes or units of any method or device disclosed thus can be combined in any combination. Unless explicitly stated otherwise, each feature disclosed in the specification (including the accompanying claims, abstract and drawings) can be replaced by an alternative feature providing the same, equivalent or similar purpose. And in the unit claims in which several apparatuses are enumerated, several of these apparatuses can be embodied by the same hardware item.

[0042] Similarly, it is to be understood that the features of the disclosure sometimes are grouped together in a single embodiment, figure or description thereof for clarity purpose. However, it should be clear to a person of ordinary skill in the art that this method of grouping is not to be interpreted as expressing a wish that the disclosure require more features than are explicitly recited in each claim. More precisely, the scope of the disclosure is to be determined based on the appended claims as construed according to the principles of patent law and the interpretative doctrines of courts. In other words, it is deemed that the claims are expressly incorporated by reference herein such that the claims are part of the detailed description.

[0043] The existing organic material packaged radio frequency device has a large cavity structure due to the large CTE difference between the metal and the organic material, and the radio frequency device is a filter and is isolated from the outside. The device generates a large stress under high temperature and thermal shock test conditions, thereby damaging the overall packaging structure of the device, easily causing the organic material to bulge, the outer lead electrode to break, and the like, resulting in poor reliability. In addition, the film material packaging structure has poor heat dissipation effect compared with a silicon-based or metal package.

[0044] Specifically, the outer lead electrode of the radio frequency device structure in the prior art is in contact with the wall and the roof in most areas. Under high temperature conditions, the mismatched thermal expansion coefficients between the metal and the film layer cause a large stress to be generated, which damages the electrode structure, causes the outer lead electrode and the device electrode to break and be disconnected, and affects the reliability of the device. In addition, the packaging structure has a large area of suspended cavity, which is supported by the hardware of the top film itself, which is relatively fragile and easy to cause the cavity structure to collapse. The radio frequency device has a relatively high heat dissipation requirement, and the film material is inherently poor in heat dissipation compared with a silicon-based or metal.

[0045] To solve at least one of the technical problems of the existing radio frequency device due to poor structural stability, the disclosure provides a radio frequency device and a preparation method thereof.

[0046] As shown in Figures 1-6 An aspect of the disclosure provides a radio frequency device 100, 100' or 100", wherein the radio frequency device 100, 100' or 100" comprises a radio frequency structure and a packaging structure.

[0047] The radio frequency structure is used to realize the radio frequency function of the radio frequency device; and

[0048] The packaging structure covers the radio frequency structure to achieve the packaging of the radio frequency structure. The packaging structure includes multiple external electrodes 201. Each external electrode 201 is in contact with the radio frequency structure and is attached to the back surface of the packaging structure facing away from the radio frequency structure to improve the rigidity of the main body of the packaging structure.

[0049] The radio frequency (RF) structure serves as the core of the RF functionality of RF devices, ensuring the realization of these RF functions.

[0050] The packaging structure covers and encapsulates the main RF functional structure of the RF structure, thereby forming a closed space k0 between the packaging structure and the RF structure. With the help of the closed space k0, the RF function of the RF structure can be realized in a stable RF environment, ensuring the performance stability of the device and preventing the main body of the packaging structure from collapsing towards the closed space k0.

[0051] On the back surface of the package structure opposite to the RF connector, multiple external electrodes 201 are attached. These external electrodes 201 are laid out over a large area on the back surface of the main body of the package structure, increasing the contact area between the external electrodes 201 and the back surface of the package structure. Simultaneously, the external electrodes 201 are connected to the RF connector, allowing the contact points with the RF connector to provide support and pull on the main body of the package structure. This improves the rigidity of the package structure, reducing the impact of thermomechanical stress on the electrodes of the RF connector, the package structure, the external electrodes 201, and the flip-chip electrodes, thus reducing the possibility of electrode structure damage. Furthermore, it also improves the structural strength of the enclosed space k0 and the heat dissipation efficiency of the device. The external electrodes also serve to lead out the electrodes, which will not be elaborated further here.

[0052] Therefore, the radio frequency device described in this embodiment can improve the structural stability of the package structure by increasing the strength of the cavity structure, and further achieve better heat dissipation through the external electrode 201. At the same time, the structure of the radio frequency device is extremely simple, allowing it to be obtained through a very simple fabrication process, thus achieving the technical effect of reducing manufacturing costs.

[0053] It should be noted that, in the embodiments of this disclosure, the structural surface of a component structure facing the functional layer 102 is generally the front surface of the component structure, while the structural surface facing away from the functional layer 102 is generally the back surface of the component structure.

[0054] like Figures 1-6 As shown, according to an embodiment of this disclosure, the radio frequency structure includes a substrate 101, a functional layer 102, and a plurality of bottom electrodes 103. Wherein, Figure 1 for Figure 2a sectional view along the section line Q1-Q2 of the perspective view shown, Figure 3 As shown in the sectional view along the section line Q3-Q4 of the perspective view shown. Figure 4 As shown in the sectional view along the section line Q3-Q4 of the perspective view shown.

[0055] The substrate 101 is used to support the radio frequency structure and the packaging structure;

[0056] The functional layer 102 is arranged on the upper surface of the middle region of the substrate 101, and is used to realize the radio frequency function;

[0057] The plurality of bottom electrodes 103 are arranged on the upper surface of the substrate 101 along the edge of the upper surface of the substrate 101 and around the functional layer 102.

[0058] As shown in the sectional view along the section line Q3-Q4 of the perspective view shown. Figure 1 、 Figure 3 and Figure 10 The substrate 101 is a wafer substrate, which mainly serves as the basis of the formation structure of the device and plays a supporting role for the device.

[0059] The functional layer 102 is a surface device arranged on the substrate 101, which is mainly used to play the radio frequency function. After the packaging structure is packaged with the radio frequency structure, the functional layer 102 is in the closed space k0 formed between the substrate 101 and the packaging structure, so that the packaging structure realizes the protection and isolation of the functional layer 102.

[0060] The plurality of bottom electrodes 103 are lead-out electrodes of the radio frequency structure, which are used to realize the connection with the external lead electrodes. The plurality of bottom electrodes 103 are arranged in a distributed manner along the upper surface of the substrate 101, specifically along the edge of the upper surface of the substrate 101, while being distributed around the functional layer 102, which can be arranged in a uniform or symmetrical manner.

[0061] As shown in the sectional view along the section line Q3-Q4 of the perspective view shown. Figures 1-6 According to the embodiment of the present disclosure, the packaging structure further comprises a support wall 202, a top layer film 203 and a plurality of flip electrodes 204.

[0062] The support wall 202 is convexly arranged on the edge of the upper surface of the substrate 101 around the functional layer 102, and is a closed ring-shaped convex structure;

[0063] The top layer film 203 is the main body of the packaging structure, which is arranged corresponding to the region formed by the support wall 202 around the functional layer 102, and forms the closed space k0 between the radio frequency structure and the packaging structure, which is used to make the radio frequency function of the functional layer more stable;

[0064] The plurality of flip electrodes 204 correspond one-to-one to the plurality of external lead electrodes 201, and are arranged on the back surface of the corresponding external lead electrode 201 on the top layer film 203, and are in contact with the back surface of the external lead electrode 201.

[0065] The support wall 202 serves as a support structure between the substrate 101 of the packaging structure and the radio frequency structure. It is used to separate the packaging structure and the radio frequency structure based on the substrate 101, thereby forming a closed space k0. The support wall 202 is formed as a closed annular protrusion that surrounds the middle area of ​​the upper surface of the substrate 101, thereby sealing the perimeter of the closed space k0 and ensuring the spatial strength and structural stability of the closed space k0.

[0066] The top layer film 203 is packaged on the upper surface area of ​​the substrate 101 of the radio frequency structure corresponding to the closed space k0. The edge of the top layer film 203 is generally in contact with the upper surface of the support wall 202 so that the top layer film 203 can cooperate with the support wall 202 and the upper surface of the substrate 101 to seal the closed space k0.

[0067] Multiple flip electrodes 204 are provided, each corresponding to and connected to an external electrode 201. Specifically, the flip electrodes 204 are disposed on the back surface of the functional layer 202 of the external electrode 201, facing away from the RF structure, and are spatially interleaved with the functional layer 202. The flip electrodes 204 serve as contact electrodes for the external leads of the device, such as... Figure 6 The two external electrodes 201 shown are interconnected and spaced apart from adjacent external electrodes 201, so that the two flip electrodes 204 corresponding to the two adjacent external electrodes 201 can be used for input and output, while the two flip electrodes 204 corresponding to the two interconnected external electrodes 201 can be used for grounding. Therefore, by means of the above-described RF structure of this embodiment, the device can connect different ground pads above the chip roof via metal, thereby further improving the out-of-band rejection level of the RF device's filter.

[0068] Therefore, the above-described RF device structure can reduce the impact of thermomechanical stress on the top layer film 203, external electrode 201, bottom electrode 103, and flip electrode 204. Furthermore, the flip electrode 204 can be separated from the bottom electrode 103 via RDL (rewiring technology), preventing the flip electrode 204 from directly acting on the bottom electrode 103 when under stress. Finally, by increasing the contact area between the external electrode 201 and the top layer film 203, the external electrode 201 can pull the top layer film 203 in the horizontal direction, improving the rigidity of the top layer film 203. Moreover, by setting a large-area metal external electrode 201 on the surface of the top layer film 203, the strength of the cavity structure (such as the enclosed space k0) and the heat dissipation efficiency of the device can be improved.

[0069] like Figures 1-6 As shown, according to an embodiment of the present disclosure, the edge of the top film 203 facing the front surface of the radio frequency structure contacts the end face of the support wall 202 to achieve encapsulation of the radio frequency structure by the top film 203.

[0070] The top layer film 203 is used to achieve the film encapsulation effect of the radio frequency structure in this embodiment of the present disclosure. It cooperates with the support wall 202 and the upper surface of the substrate 101 to enclose the functional layer 102 disposed in the middle region of the upper surface of the substrate 101 in the enclosed space k0. Part or all of the end face of the support wall 202 (i.e., its upper end face facing away from the upper surface of the substrate 101) is in closed contact with the edge of the front surface of the top layer film 203. Specifically, the bonding contact between the end face of the support wall 202 and the lower surface of the top layer film 203 can be achieved through a bonding process, thereby achieving the encapsulation effect. Simultaneously, the closed annular support wall 202 can also pull the top layer film 203 outwards, thereby further strengthening the structural strength of the encapsulation structure with the top layer film 203 as the main body and improving the rigidity of the top layer film 203.

[0071] like Figures 1-6 As shown, according to an embodiment of this disclosure, the packaging structure further includes a plurality of electrode holes k1 or a plurality of notches k2.

[0072] Multiple electrode holes k1 are inserted through the support wall 202, corresponding one-to-one with the positions of multiple bottom electrodes 103, so that the bottom electrodes 103 are exposed outside the support wall 202;

[0073] Multiple notches k2 are formed along the outer edge of the support wall 202 and correspond to the positions of multiple bottom electrodes 103, so that the bottom electrodes 103 are exposed outside the support wall.

[0074] like Figure 1 and Figure 2 As shown, electrode hole k1 is a through-hole in the support wall 202 from top to bottom, penetrating the support wall 202 so that the bottom electrode 103 disposed on the upper surface of the substrate 101 is exposed outside the support wall 202, thus ensuring that the support wall 202 cannot cover the bottom electrode 103. The number of electrode holes k1 is consistent with the number of bottom electrodes 103, allowing the bottom electrode 103 to be exposed relative to the support wall 202 through the corresponding electrode hole k1. When the top film 203 covers the support wall 202 to achieve a sealing effect, it is necessary to ensure that after the film coating is completed, a through-hole is also provided on the top film 203 at the position corresponding to the electrode hole k1, connecting the electrode hole k1 to the outside of the top film 203. This also ensures the consistency of the upper and lower structures and improves structural stability.

[0075] like Figure 3 and Figure 4As shown, the notch k2 is an opening of the support wall 202 from the outer edge towards the inside, which opens the outer wall of the support wall 202, so that the bottom electrode 103 arranged on the upper surface of the substrate 101 is exposed outside the support wall 202, that is, the support wall 202 cannot cover the bottom electrode 103. Wherein, the number of the notch k2 is consistent with the number of the bottom electrode 103, and the bottom electrode 103 can be exposed relative to the support wall 202 through the corresponding notch k2. Wherein, when the top film 203 is covered on the support wall 202 to achieve the effect of packaging and sealing, it is necessary to ensure that after the film covering is completed, the outer edge of the top film 203 at the position corresponding to the notch k2 is also provided with an opening that opens the outer edge of the top film 203, so that the notch k2 is through the top film 203, and the consistency of the upper and lower structures can also be ensured, and the structural stability is improved.

[0076] As shown in the drawings, Figures 1-6 According to an embodiment of the present disclosure, each of the plurality of outer lead electrodes 201 comprises a main body layer and an outer lead layer.

[0077] The main body layer is attached to the back surface of the top film 203 away from the functional layer 102 of the radio frequency structure;

[0078] The outer lead layer is connected with the main body layer to form an integrally formed structure layer;

[0079] Wherein, the outer lead layer is in contact with the bottom electrode 103 and the substrate 101 of the radio frequency structure at the corresponding electrode hole k1 of the plurality of electrode holes k1, and covers the corresponding bottom electrode 103; or

[0080] The outer lead layer is in contact with the bottom electrode 103 and the substrate 101 of the radio frequency structure in the corresponding notch k2 of the plurality of notches k2, and covers the corresponding bottom electrode 103.

[0081] The main body layer of the outer lead electrode 201 is the part attached and extended on the upper surface of the top film 203, and the other part is extended and covered on the inner wall of the electrode hole k1 or the notch k2 to the bottom surface of the electrode hole k1 or the notch k2 to form the outer lead layer. The outer lead electrode 201 is an integrally formed structure layer, so as to ensure that the main body layer pulls the top film 203 outward in the horizontal direction when the outer lead layer is in contact with the bottom electrode 103 and covers the inner wall of the electrode hole k1 or the notch k2, improve the structural rigidity, and ensure the structural stability of the entire packaging structure.

[0082] Wherein, the bottom electrode 103 on the bottom surface of the electrode hole k1 or the notch k2 is covered by the outer lead layer of the outer lead electrode, so that the bottom electrode 103 is not in contact with the support wall 202.

[0083] As shown in the drawings, Figures 1-6As shown, according to an embodiment of this disclosure, the bottom electrode 103 does not contact the support wall 202, and a gap f is provided on the bottom surface of the electrode hole k1, the gap f being spaced between the outer lead layer and the support wall 202 along the outer edge of the outer lead layer.

[0084] like Figure 1 and Figure 2 , Figure 14 As shown, the portion of the outer lead layer of the outer lead electrode 201 located on the bottom surface of the electrode hole k1 has a gap f between its edge facing the outer side of the device structure and the support wall 202. This gap f is generally an annular slit with a certain gap and length, mainly used to separate the outer lead layer and the support wall 202, forming a non-contact area between them, which can reduce the impact of thermomechanical stress on the film encapsulation structure of the device.

[0085] like Figures 1-6 As shown, according to an embodiment of this disclosure, the slit length r1 of the slit f and the total perimeter r0 of the portion of the outer layer on the bottom surface of the electrode hole k1 satisfy the following condition: r1 ≤ r0 / 3.

[0086] like Figure 1 and Figure 2 , Figure 14 As shown, to ensure that the size of the non-contact area between the two meets the requirements for the strength of the encapsulation structure, the length r1 of the gap f (as shown) needs to be such that... Figure 14 The arrowed arc r1 in the gap f shown in the figure and the total perimeter of the portion of the outer layer on the bottom surface of the electrode hole k1 (as shown in the figure) Figure 14 The arrowed arcs (r0) corresponding to the gaps f shown satisfy the following condition: r1 is less than or equal to 1 / 3 of r0.

[0087] like Figures 1-6 As shown, according to the embodiments of this disclosure, in order to ensure that the main body layer can stretch the top membrane 203 based on the structure of the outer layer, thereby improving the structural rigidity of the top membrane 203 and achieving better heat dissipation, as follows... Figure 5 As shown, the coverage area s1 of the main layer on the back surface of the top membrane 203 and the contact area s2 between the corresponding flip electrode 204 and the main layer satisfy the following condition: s1 ≥ 2s2. The area s1 of the main layer extending onto the top membrane 203 can actually be close to the area of ​​the entire back surface of the top membrane 203. This not only further improves structural rigidity and prevents the top membrane 203 from collapsing, but also further enhances the structural heat dissipation effect.

[0088] like Figures 1-6 As shown, according to embodiments of this disclosure, the materials of the top membrane and the supporting wall include organic materials, wherein the organic materials include epoxy resin materials.

[0089] It can be seen that, based on the structure design of the radio frequency device according to the above embodiment of the present disclosure, the radio frequency device can at least achieve the following technical effects: (1) reducing the influence of thermal mechanical stress on the film type packaging structure of the device; (2) improving the heat dissipation effect of the film type packaging body through the structure design of the electrode; (3) reducing the processing difficulty of the process through simple structure design; (4) improving the bearing capacity of the device to external force and improving the reliability of the device; (5) connecting different ground pads through metal above the chip roof, thereby further improving the out-of-band suppression level of the filter.

[0090] As shown in Figures 7-16 , another aspect of the present disclosure provides a preparation method of the above radio frequency device, comprising steps S701-S702.

[0091] In step S701, a radio frequency structure is formed for realizing the radio frequency function of the radio frequency device;

[0092] In step S702, a packaging structure is covered on the radio frequency structure, comprising step S7021,

[0093] In step S7021, a plurality of external electrodes 201 are attached on the back surface of the packaging structure away from the radio frequency structure, and each external electrode 201 of the plurality of external electrodes 201 is in contact with the radio frequency structure to improve the rigidity of the main body of the packaging structure.

[0094] Based on the preparation method of the radio frequency device structure according to the above embodiment of the present disclosure, the preparation process of the film coating scheme for the radio frequency device structure is simpler, the preparation time is greatly shortened, and the preparation cost is reduced. In addition, the device structure is simple, which can effectively prevent the packaging structure from collapsing, has better structural stability, and can also ensure the heat dissipation effect of the device, which is conducive to improving the service life of the device and ensuring better radio frequency effect of the device.

[0095] For better explanation of the preparation method shown in Figure 7 and the technical content of the radio frequency device structure shown in Figures 1-6 , the preparation method of the radio frequency device shown in Figures 1-2 , the following preparation process steps are provided:

[0096] Among them, for the radio frequency device wafer level packaging structure diagram shown in Figure 1 , the specific implementation steps S1-S5 are as follows: Figures 8 to 16

[0097] In step S1, as shown in Figure 8 , it is a single chip cross-sectional view of the wafer of the radio frequency device, which includes a substrate 101, a functional layer 102 as a functional area of the device, and a bottom electrode 103 as an electrode area of the radio frequency structure.​

[0098] In step S2, as shown in Figure 9 , Figure 10 , a support wall 202 is prepared on the surface of the wafer substrate 101 by spin coating or film pasting, and then the electrode hole k1 is opened at the bottom electrode 103 by means of photolithography or laser drilling and solidification. The support wall 202 is generally an organic material such as epoxy resin, and the thickness is generally between 10 microns and 60 microns. As shown in Figure 10 , it is a three-dimensional schematic diagram of the support wall 202 after preparation.

[0099] In step S3, as shown in Figure 11 , Figure 12 , a top film 203 is prepared above the support wall 202 by film pasting, and then the electrode hole k1 is opened at the bottom electrode 103 by means of photolithography or laser drilling, and then the support wall 202 and the top film 203 form a sealed structure to protect the functional layer 102 by means of high-temperature solidification to form a cavity (i.e. closed space k0). As shown in Figure 12 , it is a three-dimensional schematic diagram of the top film 203 after preparation. The top film 771 is generally an organic material such as epoxy resin, and the thickness is generally between 10 microns and 60 microns.

[0100] In step S4, as shown in Figures 13-15 , the outer electrode 201 is prepared and formed by means of physical vapor deposition and photolithography and electroplating to a thickness of 10 microns. The material of the outer electrode 201 is generally copper, and can also be gold, aluminum and other conductor materials, and the thickness is generally controlled to be between 5 and 20 microns. The outer electrode 201 is connected to the bottom electrode 103 and extends to the upper surface of the top film 203. The coverage area s1 of the outer electrode 201 on the top film 203 needs to be more than twice the two-dimensional planar area s2 of the flip electrode 204.

[0101] In addition, as shown in Figure 14 , the outer periphery of the part of the outer electrode 201 on the bottom surface of the electrode hole k1 needs to maintain a certain interval with the support wall 202 to form a gap f, and the interval distance between the two is greater than or equal to 2 microns, and in addition, the length r1 of the area of the gap f is more than one-third of the total circumference r0 of the bottom part of the outer electrode 201. Wherein, Figure 14 is a two-dimensional planar schematic diagram of the outer electrode hole, r1 represents the circumference of the gap f between the outer electrode 201 and the support wall 202, and d represents the interval distance between the outer electrode 201 and the support wall 202, i.e. the gap width. Figure 15 is a three-dimensional schematic diagram of the device after preparation of the outer electrode 201;

[0102] In step S5, asFigure 16 As shown, the flip electrode 204 is prepared on the outer lead electrode 201 above the top film 203 by physical vapor deposition plus lithography and plating. The flip electrode 204 structure material can be copper / tin combination or tin metal combination. Figure 2 As shown, the flip electrode 204 is prepared on the outer lead electrode 201 above the top film 203 by physical vapor deposition plus lithography and plating. The flip electrode 204 structure material can be copper / tin combination or tin metal combination.

[0103] It should be noted that, as shown in Figure 3 and Figure 4 The device bottom electrode 103 is not entirely arranged in the package structure inside the support wall 202, that is, in the form of a gap k2, rather than in the form of an electrode hole k1, and the processing steps of the support wall 202 and the top film 203 are referred to S1-S3. Since the device bottom electrode 103 is not entirely inside the support wall 202, the outer edge of the bottom part of the outer lead layer is necessarily not in direct contact with the outer side of the support wall 202, so that the outer lead layer can be directly extended above the top film 203 to form the main body layer of the outer lead electrode 201, and finally repeat step S5 to complete the preparation of the flip electrode 204, thereby forming the final structure form.

[0104] Based on the preparation method of the radio frequency device structure of the above-mentioned embodiments of the present disclosure, the film coating scheme can make the preparation process of the radio frequency device structure simpler, greatly shorten the preparation time, and reduce the preparation cost.

[0105] So far, the embodiments of the present disclosure have been described in detail with reference to the accompanying drawings.

[0106] The above-described specific embodiments further detail the purpose, technical solutions and beneficial effects of the present application. It should be understood that the above-described embodiments are only specific embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A radio frequency device, wherein, The application relates to a radio frequency device and a manufacturing method thereof. The radio frequency device comprises: a radio frequency structure for realizing radio frequency functions of the radio frequency device; and a packaging structure covering the radio frequency structure, wherein the radio frequency structure comprises: a substrate for supporting the radio frequency structure and the packaging structure; a functional layer arranged on an upper surface of a middle region of the substrate for realizing the radio frequency functions; a plurality of bottom electrodes arranged on the upper surface of the substrate along edges of the upper surface of the substrate and distributed around the functional layer, wherein the packaging structure comprises: a support wall protruding from edges of the upper surface of the substrate around the functional layer and being a closed ring-shaped protruding structure, the support wall being not in contact with the bottom electrodes; a top layer film being a main body of the packaging structure and being arranged corresponding to a region formed by the support wall around the functional layer to form a closed space between the radio frequency structure and the packaging structure; a plurality of electrode holes penetrating the support wall and corresponding to positions of the plurality of bottom electrodes so that the bottom electrodes are exposed outside the support wall; or a plurality of notches opened on the support wall along outer edges of the support wall and corresponding to positions of the plurality of bottom electrodes so that the bottom electrodes are exposed outside the support wall; a plurality of external lead electrodes, each of the plurality of external lead electrodes comprising: a main body layer attached to a back surface of the top layer film away from the functional layer of the radio frequency structure; an external lead layer integrally formed with the main body layer, wherein the external lead layer is attached to inner walls of corresponding electrode holes of the plurality of electrode holes or corresponding notches of the plurality of notches and covers the corresponding bottom electrodes, and is in contact with the bottom electrodes and the substrate of the radio frequency structure, 2. The radio-frequency device of claim 1, wherein, wherein a spacing gap is arranged on a bottom surface of the electrode hole, the spacing gap spacing the external lead layer from the support wall along outer edges of the external lead layer, and a length r1 of the spacing gap and a total circumference r0 of a part of the external lead layer on the bottom surface of the electrode hole satisfy: r1<=r0 / 3. The packaging structure further comprises:

3. The radio-frequency device of claim 1, wherein, a plurality of flip electrodes corresponding to the plurality of external lead electrodes and arranged on back surfaces of corresponding external lead electrodes on the top layer film and in contact with the back surfaces of the external lead electrodes.

4. The radio-frequency device of claim 2, wherein, Edges of a front surface of the top layer film towards the radio frequency structure are in contact with end surfaces of the support wall to realize packaging of the radio frequency structure by the top layer film.

5. The radio-frequency device according to any of claims 2-4, wherein, A covering area s1 of the main body layer on the back surface of the top layer film and a contact area s2 between the corresponding flip electrode and the main body layer satisfy: s1>=2s2.

6. A method of making the radio frequency device of any of claims 1-5, wherein, Materials of the top layer film and the support wall comprise organic materials, wherein the organic materials comprise epoxy resin materials. The application relates to a radio frequency device and a manufacturing method thereof. The radio frequency device comprises: a radio frequency structure for realizing radio frequency functions of the radio frequency device; and a packaging structure covering the radio frequency structure, wherein the radio frequency structure comprises: a substrate, a functional layer as a functional region, and a plurality of bottom electrodes as electrode regions, the packaging structure covering the radio frequency structure comprises: The support wall is arranged on the substrate surface, and a top layer film is arranged on the support wall, wherein the support wall is not in contact with the bottom electrode, and the support wall and the top layer film form a sealing structure for protecting the functional layer; A plurality of electrode holes or a plurality of notches are formed in the support wall and the top layer film at positions corresponding to the plurality of bottom electrodes; A plurality of external electrodes are attached to a back surface of the encapsulation structure away from the radio frequency structure, wherein each of the plurality of external electrodes comprises a main body layer attached to a back surface of the top layer film away from the functional layer of the radio frequency structure, and an external lead layer integrally formed with the main body layer, the external lead layer being attached to an inner wall of a corresponding electrode hole of the plurality of electrode holes or a corresponding notch of the plurality of notches and covering a corresponding bottom electrode, and being in contact with the bottom electrode and the substrate of the radio frequency structure, wherein a spacing gap is arranged on a bottom surface of the electrode hole, the spacing gap spacing the external lead layer from the support wall along an outer edge of the external lead layer, and a length r1 of the spacing gap and a total circumference r0 of a portion of the external lead layer on the bottom surface of the electrode hole satisfy: r1≤r0 / 3.

Images