TW202239058A - Antenna structure and method of forming the same - Google Patents

Abstract

An antenna structure includes a core substrate and a pair of patch antennas. The pair of patch antennas is disposed on opposite sidewalls of the core substrate, and the core substrate between the pair of patch antennas is a cavity free of conductive material.

Description

Antenna structure and its forming method

Embodiments of the present invention relate to an antenna structure, in particular to a sidewall antenna structure and a forming method thereof.

Electronic devices often include integrated chips with wireless communication components. In general, integrated chips can use antennas including off-chip antennas (i.e., external antennas not integrated into the integrated chip) or on-chip antennas (i.e., integrated (or integrated) into integrated chip antenna) wireless communication components. Antennas for high-frequency wireless communication components can use patch antennas arranged on high-frequency substrates or high-frequency printed circuit boards.

In recent years, the demand for wireless communication in consumer electronic products (such as smartphones, smart wearable devices, tablet computers, or car satellite navigation, etc.) has continued to increase, and electronic products are expected to have lighter weight, thinner size and better performance. In some electronic devices using wireless communication components including off-chip antennas, it may not be possible to reduce product size because the off-chip antennas occupy extra volume. For these devices, wireless communication components including antennas on a chip can be used to reduce product size. While existing on-chip antennas have generally met needs, they have not been satisfactory in all respects.

An embodiment of the present invention provides an antenna structure, including: a core substrate and a pair of patch antennas. The pair of patch antennas are relatively disposed on opposite side walls of the core substrate, and the core substrate between the pair of patch antennas is a cavity that does not contain conductive material.

An embodiment of the present invention provides a method for forming an antenna structure, including: providing a core substrate having a first antenna layer above a top surface and a second antenna layer below a bottom surface. The first antenna layer and the core substrate are patterned to form a first opening and a second opening exposing the second antenna layer, wherein the first opening and the second opening are located on opposite sides of the core substrate. Filling the third antenna layer into the first opening and the second opening. The first antenna layer and the second antenna layer are patterned to expose the core substrate and leave the first antenna layer and the third antenna layer surrounding the third antenna layer and part of the second antenna layer under the core substrate. A cutting process is performed on the core substrate, the first antenna layer, the second antenna layer and the third antenna layer along a circular path. After this dicing process, the first antenna layer, the second antenna layer, and the third antenna layer within the loop path form a pair of patch antennas embedded in opposite sidewalls of the core substrate within the loop path. The antennas are arranged opposite to each other and the core substrate between the pair of patch antennas is a cavity that does not contain conductive materials.

An embodiment of the present invention further provides a method for forming an antenna structure, including: providing a core substrate having a first antenna layer above a top surface and a second antenna layer below a bottom surface. A first opening and a second opening are formed through the first antenna layer, the core substrate, and the second antenna layer, wherein the first opening and the second opening are located on opposite sides of the core substrate. The third antenna layer is formed on the side walls of the first opening and the second opening, on the top surface of the first antenna layer, and under the bottom surface of the second antenna layer. patterning the first antenna layer, the second antenna layer, and the third antenna layer to expose the core substrate and leave the first antenna layer, the second antenna layer, and the third antenna layer adjacent to the first opening and the second opening Three antenna layers, leaving the third antenna layer on the sidewalls of the first opening and the second opening. A cutting process is performed on the core substrate, the first antenna layer, the second antenna layer and the third antenna layer along the circular path. After the dicing process, the first antenna layer, the second antenna layer, and the third antenna layer within the loop path form a pair of patches on the surface of a pair of notches on opposite sidewalls of the core substrate within the loop path For the antenna, the pair of notches are oppositely arranged, and the core substrate between the pair of patch antennas is a cavity that does not contain conductive materials.

The following disclosure provides a number of embodiments, or examples, for implementing different elements of the provided subject matter. Specific examples of each component and its configuration are described below to simplify the description of the embodiments of the present invention. Of course, these are just examples, not intended to limit the embodiments of the present invention. For example, if a description mentions that a first element is formed on a second element, it may include an embodiment in which the first and second elements are in direct contact, or may include an additional element formed between the first and second elements , so that they are not in direct contact with the example. In addition, embodiments of the invention may have repeated reference numerals in various examples. This repetition is for the purpose of brevity and clarity and not to show the relationship between the different embodiments and/or configurations discussed.

In addition, in some embodiments of the present invention, terms such as "connected" and "interconnected" related to bonding and connection, unless otherwise specified, may mean that two structures are in direct contact, or may also mean that two structures are not in contact with each other. In direct contact, where other structures are placed between the two structures. And the terms about joining and connecting may also include the situation that both structures are movable, or both structures are fixed.

Furthermore, terms relative to space may be used, such as "below", "below", "lower", "above", "higher", etc., for the convenience of description The relationship between one component or feature(s) and another component(s) or feature(s) in a drawing. Spatially relative terms are intended to encompass different orientations of the device in use or operation, as well as orientations depicted in the drawings. When the device is turned to a different orientation (rotated 90 degrees or otherwise), the spatially relative adjectives used therein shall also be interpreted in accordance with the turned orientation.

The terms "about", "approximately" and "approximately" used herein usually mean within ±20% of a given value, preferably within ±10%, and more preferably within ±5%, Or within ±3%, or within ±2%, or within ±1%, or within 0.5%. The numerical values given here are approximate numerical values, that is, in the absence of specific descriptions of "about", "approximately" and "approximately", the given numerical values may still imply "about", "approximately", "approximately" "probably" meaning.

Some embodiments of the invention are described below, and additional steps may be provided before, during and/or after various stages described in these embodiments. Some of the stages described may be replaced or omitted in different embodiments. The antenna structure of the embodiments of the present invention can add additional components. Some of the components described may be substituted or omitted in different embodiments. Although some embodiments discussed perform steps in a particular order, the steps may be performed in another logical order.

In the conventional technology, the pair of patch antennas is usually arranged on the front of the substrate of the antenna structure, and in order to increase the thickness of the cavity between the pair of patch antennas to exert high-frequency performance, generally speaking, a pair of patch antennas can be formed between the pair of patch antennas. multiple film layers. However, since the multiple film layers and patch antenna pairs are formed in different steps, the thickness of the cavity between the patch antenna pairs may be affected by the material and process used to form the film layers, making it difficult to control the cavity thickness , and forming the patch antenna pair in different steps may make the alignment of the patch antenna pair difficult to control, thereby affecting the performance and product yield of the patch antenna.

Embodiments of the present invention provide an antenna structure and a method for forming the antenna structure. The pair of patch antennas are arranged on the side wall of the substrate of the antenna structure, so that the thickness of the cavity can be controlled. In addition, the method provided by the embodiment of the present invention can simultaneously form a pair of patch antennas, so as to improve the alignment accuracy of the patch antennas.

1A, 1B and 2 are schematic diagrams illustrating an antenna structure 10 according to some embodiments of the present invention. FIG. 1A shows a perspective view of the antenna structure 10 , and FIG. 1B is a top view of the antenna structure 10 . The antenna structure 10 includes a core substrate 100 , a first dielectric layer 111 , a second dielectric layer 112 , and a pair of patch antennas A1 , A2 and A3 . In some embodiments, the material of the core substrate 100 may include: bismaleimide triazine resin (Bismaleimide Triazine resin), paper phenolic resin (paper phenolic resin), composite epoxy resin (composite epoxy), poly Polyimide resin, glass fiber, other suitable insulating materials, or a combination of the foregoing.

A first dielectric layer 111 and a second dielectric layer 112 may be provided above and below the main surface S of the core substrate 100 as required, wherein the first dielectric layer 111 may be disposed above the core substrate 100, and the second dielectric layer 112 may be It is disposed under the core substrate 100 . For example, the materials of the first dielectric layer 111 and the second dielectric layer 112 may be the same or different, each including: epoxy resin, bismaleimide-triazine resin, polyimide, Ajinomoto build-up film (ABF), polyphenylene oxide (polyphenylene oxide, PPO), polypropylene (polypropylene, PP), polymethyl methacrylate (polymethyl methacrylate, PMMA), polytetrafluoroethylene (polytetrafluoroethylene, PTFE) ), fiberglass, or other suitable materials. In some embodiments, the first dielectric layer 111 and the second dielectric layer 112 are prepreg (prepreg) materials obtained by prepreg insulation sheets, glass fibers, or other materials. According to some embodiments of the present invention, the core substrate 100 , the first dielectric layer 111 and the second dielectric layer 112 may include the same material.

Referring to FIG. 1B , it should be noted that, in order to clearly show the positions of the patch antenna and the core substrate, FIG. 1B only shows a top view including the core substrate 100 and the patch antenna pairs A1 , A2 and A3 . Referring to FIGS. 1A and 1B , the pair of patch antennas A1 , A2 and A3 are oppositely disposed on opposite sidewalls of the core substrate 100 . The core substrate 100 between the pair of patch antennas is a cavity that does not contain conductive material, such as the cavity C1 between the pair of patch antennas A1 and the cavity C2 between the pair of patch antennas A2 . In this article, "cavity" means that no conductive material is included, and it does not mean that voids are necessarily formed therein (that is, voids may or may not be included in the cavity). Therefore, according to some embodiments of the present invention, the patch antenna pair The core substrate without conductive material between them is called a "cavity". In further embodiments, a core substrate and a dielectric layer may be included between the pair of patch antennas, which does not contain conductive materials. Therefore, in these embodiments, the core substrate and dielectric layer between the pair of patch antennas Also for cavities. As shown in FIG. 1B , the pair of patch antennas A1 , A2 and A3 are embedded in opposite sidewalls of the core substrate 100 , and one sidewall of the patch antennas is coplanar with one sidewall of the core substrate 100 . The material of the patch antenna pairs A1 , A2 and A3 may include conductive materials such as copper, aluminum, tungsten, silver, gold, nickel, or a combination of the aforementioned materials. As described below in the process of forming the antenna structure, the embodiment of the present invention can simultaneously form the pair of patch antennas to improve the alignment accuracy of the pair of patch antennas, and the cavity between the pair of patch antennas can be determined according to the product design thickness to achieve the desired frequency performance.

In some embodiments, at least one patch antenna in the patch antenna pair can extend higher than the top surface of the core substrate 100 . For example, as shown in FIG. 1A , one of the pair of patch antennas A1 extends higher than the top surface of the core substrate 100 along a direction D3 perpendicular to the main surface S of the core substrate 100 . In some embodiments, at least one patch antenna in the patch antenna pair may extend below the bottom surface of the core substrate 100 . For example, as shown in FIG. 1A , one of the pair of patch antennas A2 extends below the bottom surface of the core substrate 100 along a direction D3 perpendicular to the main surface S of the core substrate 100 . According to some embodiments of the present invention, the pair of patch antennas A1, A2, and A3 can also be embedded in the sidewalls of the first dielectric layer 111 and the second dielectric layer 112, and the pair of patch antennas can also extend along the direction D3 to be higher than the first dielectric layer. A patch antenna with one dielectric layer 111 or lower than the second dielectric layer 112 extending beyond the core substrate 100 may be referred to as an antenna build-up layer.

The patch antenna pair can be in various shapes in the top view. As shown in FIG. 1B, the patch antenna pair can be rectangular, partly elliptical, partly polygonal with curved corners, or other shapes. In the embodiment including the first dielectric layer 111 or the second dielectric layer 112, the first dielectric layer 111 and the antenna build-up layer embedded therein may be referred to as a build-up layer structure, similarly, the second dielectric layer 112 and the antenna build-up layer embedded therein The antenna build-up may also be referred to as a build-up structure. The build-up structure can be disposed above or below the core substrate 100 . According to the application and design requirements of the product, the size of the patch antenna can be adjusted by using the layer-up structure, and the number can be one or more. For example, by forming a multi-layer structure including a core substrate through a build-up structure, the size of the patch antenna pair can be increased to achieve a predetermined frequency performance.

Referring to FIG. 1A , in some embodiments, the antenna structure 10 may include a solder resist layer 110 covering the top surface of the antenna patch pair A1 , A3 and the first dielectric layer 111 . The antenna structure 10 may also include a solder resist layer 110 covering the antenna patch pairs A1 , A2 , A3 and the bottom surface of the second dielectric layer 112 . In some embodiments, the solder resist layer 110 can be a photosensitive material (such as an ultraviolet photosensitive material), a heat sensitive material (such as a thermosetting heat sensitive material), other suitable materials, or a combination thereof. For example, the solder resist layer 110 may include: epoxy resin, urethane, ethyl resin, or other materials.

Referring to FIG. 2 , the antenna structure 10 may further include a plurality of connectors 116 disposed on the solder resist layer 110 . The connector 116 can be used for transmitting signals. The material of the connector 116 may include metal materials such as tin or nickel. As shown in FIG. 2, according to product characteristic requirements, in the embodiment including the first dielectric layer 111 and the second dielectric layer 112, the patch antenna can only be extended to be higher than the first dielectric layer 111 but not to be lower. In the second dielectric layer 112, the pair of patch antennas A5 as shown in FIG. 2; The first dielectric layer 111 and the lower second dielectric layer 112 are the patch antenna pair A4 shown in FIG. 2 .

3A and 3B are schematic diagrams illustrating the antenna structure 20 according to other embodiments of the present invention, wherein components similar to the antenna structure 10 are marked with the same symbols, and related descriptions are not repeated here. FIG. 3A shows a perspective view of the antenna structure 20 , and FIG. 3B shows a top view of the antenna structure 20 . It should be noted that, in order to clearly show the positions of the patch antenna and the core substrate, FIG. 3B only shows the core substrate 100 and the patch antenna pair A6. Referring to FIGS. 3A and 3B , the core substrate 100 of the antenna structure 20 has a pair of notches N oppositely disposed on the opposite sidewalls. The pair of notches N runs through the core substrate 100 , and the pair of patch antennas A6 are respectively disposed on the sidewalls of the core substrate 100 exposed by the notches N. As shown in FIGS. 3A and 3B , the patch antenna pair A6 of the antenna structure 20 is conformably disposed along the notch N, so the patch antenna pair A6 is recessed in the sidewall of the core substrate 100 . In some embodiments, the pair of patch antennas A6 can extend along the direction D3 perpendicular to the main surface S of the core substrate 100 to be higher than the top surface of the core substrate 100 and/or the pair of patch antennas A6 can extend along the direction D3 perpendicular to the main surface S of the core substrate 100. The direction D3 of the surface S extends below the bottom surface of the core substrate 100 . In some embodiments, the core substrate 100 between the pair of patch antennas is a cavity that does not contain conductive material, such as the cavity C6 between the pair of patch antennas A6 .

According to some embodiments of the present invention, the antenna structure 20 may include a first dielectric layer 111 disposed on the core substrate 100 and/or a second dielectric layer 112 disposed under the core substrate 100 . In these embodiments, the pair of notches N also penetrate the first dielectric layer 111 and/or the second dielectric layer 112, and the pair of patch antennas A6 are respectively disposed on the first dielectric layer 111 and the second dielectric layer 112 exposed by the notches N. /or on the sidewall of the second dielectric layer 112 , and recessed in the sidewall of the first dielectric layer 111 and/or the second dielectric layer 112 . The patch antenna pair A6 can extend to be higher than the first dielectric layer 111 and/or lower than the second dielectric layer 112 along the direction D3. It should be noted that the pair of patch antennas A6 on the pair of notches N shown in FIG. 3A is only exemplary. In the present disclosure, multiple pairs of patch antennas can also be respectively arranged on the core substrate 100 of the antenna structure 20, the first Dielectric layer 111 and/or multiple pairs of notches on the sidewall of the second dielectric layer 112, and multiple pairs of notches can also be provided on another pair of opposite sidewalls of the core substrate 100, or the core substrate 100, the first dielectric layer 111 and another pair of opposite sidewalls of the second dielectric layer 112 .

FIGS. 4, 5, 6A-8A, 6B-8B, 6, 10A, 10B, and 11-14 are schematic diagrams illustrating a process for forming the antenna structure 10 according to some embodiments of the present invention. Referring to FIG. 4 , a core substrate 100 is provided. The core substrate 100 has a first antenna layer 101 above its top surface and a second antenna layer 102 below its bottom surface. Then, as shown in FIGS. 5 , 6A and 6B , the first antenna layer 101 and the core substrate 100 are patterned to form openings OP1 and OP2 exposing the second antenna layer 102 on opposite sides of the core substrate 100 . 5 and 6A show cross-sectional views of the patterned antenna structure 10, and FIG. 6B is a top view of the antenna structure 10, wherein the A-A cross-section in FIG. 6B may correspond to FIG. 6A. As shown in FIG. 5, the process of patterning the first antenna layer 101 and the core substrate 100 may include first patterning the first antenna layer 101 to form an opening OP exposing the core substrate 100, and then patterning the core substrate 100, The opening OP1 and the opening OP2 exposing the second antenna layer 102 are formed, as shown in FIGS. 6A and 6B . In some embodiments, the process of patterning the first antenna layer 101 may include forming a patterned mask (not shown) on the first antenna layer 101, and then using an etching process to remove part of the first antenna layer 101, to form the opening OP, and then remove the patterned mask. The first antenna layer 101 and the second antenna layer 102 may include the same or different materials, for example, may respectively include: copper, aluminum, tungsten, silver, gold, or a combination of the aforementioned materials. The patterned mask may include: dry film, liquid photoresist, other suitable materials, or a combination of the foregoing. In an embodiment where the material of the first antenna layer 101 includes copper, the aforementioned etching process may include a wet etching process, wherein the used etchant includes sulfuric acid-hydrogen peroxide solution, sodium chlorate solution, or other suitable solutions. The patterned mask can be removed using an appropriate etchant, such as copper chloride solution, sulfuric acid-hydrogen peroxide solution, sodium hydroxide solution, potassium hydroxide solution, amine solution, or other suitable solutions. In some embodiments, the process of patterning the core substrate 100 includes using a laser to remove the core substrate 100 under the opening OP.

Then referring to Figures 7A, 7B, 8A and 8B, Figures 7A and 8A are cross-sectional views of the antenna structure 10, Figures 7B and 8B are top views of the antenna structure 10, and the A-A cross-sections thereof can correspond to the 7A and 8A respectively picture. In Figures 7A and 7B, the third antenna layer 103 is filled into the openings OP1 and OP2. The material of the third antenna layer 103 may be the same as that of the first antenna layer 101 and/or the second antenna layer 102 . In some embodiments, a deposition process or an electroplating process may be used to form the third antenna layer 103 to fill the opening OP1 and the opening OP2. Next, as shown in FIGS. 8A and 8B , the first antenna layer 101 and the second antenna layer 101 are patterned. The patterning process shown in FIGS. 8A and 8B may be the same or similar to the above-mentioned process of patterning the first antenna layer 101 to form the opening OP. In some embodiments, the core substrate 100 is exposed after patterning, and the first antenna layer 101 surrounding the third antenna layer 103 is left, and the third antenna layer 103 and part of the core substrate 100 are left the next day. Wire layer 102.

Referring to FIG. 9A , the cutting process is performed along the circular path P. Referring to FIG. In some embodiments, the cutting process includes cutting the core substrate 100 , the first antenna layer 101 , the second antenna layer 102 and the third antenna layer 103 . According to some embodiments of the present invention, the annular path P may also be composed of a plurality of cutting paths. FIG. 9B also shows a plurality of antenna structures, which can be formed using a process similar to the above, which may include forming multiple openings at the same time and then forming antenna layers in these openings at the same time, and performing cutting paths including P The cutting process of _V1 , _PV2 and _PV3 and the cutting paths P _H1 , P _H2 and P _H3 forms the antenna structure 10 as shown in FIG. 1A . As shown in FIG. 9B , the circular path P may include two cutting paths P _H1 , P _H2 and two other cutting paths P _V1 , P _V2 perpendicular to the two cutting paths P _H1 , P _H2 . In other embodiments, according to design and/or process requirements, the circular path P can be circular, elliptical, rectangular, rhombus, or other suitable shapes.

Figures 10A and 10B show the antenna structure 10 after the cutting process, Figure 10A is a cross-sectional view, Figure 10B is a top view, and the A-A cross-section may correspond to Figure 10A. The first antenna layer 101, the second antenna layer 102, and the third antenna layer 103 in the loop path P form a pair of patch antennas embedded in the opposite side walls of the core substrate 100 in the loop path P. The core substrate 100 disposed opposite to each other and between the pair of patch antennas is a cavity C that does not contain conductive materials. In some embodiments, the patch antenna pair formed by the first antenna layer 101 , the second antenna layer 102 and the third antenna layer 103 may correspond to the patch antenna pair A4 in FIG. 2 . As mentioned above, the patch antenna pair of the present disclosure can be formed in the openings (such as openings OP1 and OP2, refer to FIG. 6B) formed in the same process, which can improve the alignment accuracy between the patch antenna pairs, for example In terms of alignment accuracy can be improved by about 30% compared with conventional non-simultaneously formed patch antenna pairs disposed on a substrate. In addition, since the conventional cavity distance (or cavity thickness) between the patch antenna pair is determined by the multi-layer material between the patch antenna pair, the process of forming the multi-layer material may affect the uniformity of the multi-layer material, resulting in a cavity The distance is not easy to control and the cavity distance is limited by the number of layers of the multilayer material. In some embodiments of the present invention, the cavity distance between patch antennas (for example, cavity C, refer to FIG. 10B ) can be the antenna layer (for example, the first antenna layer) 101, refer to the distance D between Figure 10B), therefore, the variation of the cavity distance (or thickness) can be better controlled through the patterning process, and is determined by the unit size (unit size) of the antenna structure after the cutting process Cavity distance, so as to achieve the desired frequency performance. In addition, since the embodiment of the present invention does not need to add an extra material layer to increase the cavity distance, the manufacturing cost can be reduced.

11-14 are schematic cross-sectional views illustrating build-up structures forming antenna structures according to some embodiments of the present invention. In some embodiments, after patterning the first antenna layer 101 and the second antenna layer 102 and before performing the dicing process, a build-up structure may be formed above and/or below the core substrate. In some embodiments of the present invention, the first build-up structure and the second build-up structure can be formed at the same time, that is, layers are built up above and below the antenna structure 10 at the same time. Referring to FIG. 11, a first dielectric layer 111 is formed on the top surfaces of the first antenna layer 101, the third antenna layer 103 and the core substrate 100 and a fourth antenna layer 104 is formed on the first dielectric layer 111, and A second dielectric layer 112 is formed under the second antenna layer 102 and the bottom surface of the core substrate 100 and a sixth antenna layer 106 is formed under the second dielectric layer 112 . In some embodiments, forming the first dielectric layer 111, the fourth antenna layer 104, the second dielectric layer 112, and the sixth antenna layer 106 includes combining the material layer of the first dielectric layer 111 and the material layer of the fourth antenna layer 104 The material layer is bonded to the top surface of the first antenna layer 101, the third antenna layer 103 and the core substrate 100 and the material layer of the second dielectric layer 112 and the material layer of the sixth antenna layer 106 are bonded to the second The bottom surface of the antenna layer 102 and the core substrate 100 . In some embodiments, a portion of the first antenna build-up layer (eg, the fifth antenna layer 105 ) may pass through the first dielectric layer 111 and connect to the third antenna layer 103 . Similarly, in some embodiments, a portion of the second antenna build-up layer (eg, the seventh antenna layer 107 ) may pass through the second dielectric layer 112 and connect to the second antenna layer 102 .

Then referring to FIG. 12, a patterning process is performed to pattern the fourth antenna layer 104, the first dielectric layer 111, the sixth antenna layer 106, and the second dielectric layer 112 to form openings OP3 and OP4. According to some embodiments of the present invention, the opening OP3 exposes the third antenna layer 103 and the opening OP4 exposes the second antenna layer 102 below the third antenna layer 103 . The process for patterning the fourth antenna layer 104 , the first dielectric layer 111 , the sixth antenna layer 106 , and the second dielectric layer 112 may be similar to that described above with respect to FIGS. 5 , 6A and 6B.

Then fill the fifth antenna layer 105 into the opening OP3 and fill the seventh antenna layer 107 into the opening OP4, as shown in FIG. 13 . The process of filling the fifth antenna layer 105 and the seventh antenna layer 107 may be similar to the above-mentioned process of filling the third antenna layer 103 into the opening OP1 and the opening OP2 in FIGS. 7A and 7B . Then the fourth antenna layer 104 and the sixth antenna layer 106 are patterned to expose the first dielectric layer 111 and the second dielectric layer 112, and leave the fourth antenna layer 104 surrounding the fifth antenna layer 105 and the surrounding The sixth antenna layer 106 of the seventh antenna layer 107 is shown in FIG. 14 . Thus, the first build-up structure comprising the first dielectric layer 111, the fourth antenna layer 104, and the fifth antenna layer 105 and the structure comprising the second dielectric layer 112, the sixth antenna layer 106, and the seventh antenna layer 107 are formed. The second layer-up structure, wherein the fourth antenna layer 104 and the fifth antenna layer 105 can be collectively referred to as the first antenna layer and the sixth antenna layer 106 and the seventh antenna layer 107 can be collectively referred to as the second antenna layer Floor. In some embodiments, after the build-up structure is formed, a dicing process as shown in FIG. The first build-up layer structure and the second build-up layer structure, after the cutting process, the first antenna layer 101, the second antenna layer 102, the third antenna layer 103, the first antenna build-up layer, And the second antenna build-up layer can form the patch antenna A1 or A3 as shown in FIG. 1 . In some embodiments, the first antenna layer 101 , the second antenna layer 102 , the third antenna layer 103 , the first antenna build-up layer, and the second antenna build-up layer comprise the same material. In some embodiments, the core substrate 101 , the first dielectric layer 111 , and the second dielectric layer 112 include the same material.

In some embodiments, the antenna build-up layer may not be formed during the build-up layer. For example, only the first dielectric layer 111 is formed when forming the first build-up structure, and the second dielectric layer 112 and the second antenna build-up layer are formed when forming the second build-up structure. In these embodiments, after the build-up structure is formed, the dicing process as shown in FIG. 9A can be performed. After dicing, the antenna layer and the second antenna build-up layer in the loop path P are formed as shown in FIG. 1A The patch antenna A2. Similarly, the first dielectric layer 111 and the first antenna build-up layer are formed when forming the first build-up structure, and only the second dielectric layer 112 is formed when forming the second build-up structure. After the dicing process, the Form the patch antenna A5 as shown in Fig. 2 . In other embodiments, only the first build-up structure or only the second build-up structure may be formed. In alternative embodiments, the first build-up structure may be formed before the second build-up structure, or vice versa.

Although in the above-mentioned embodiments, only one first build-up structure above the core substrate 100 or one second build-up structure below the core substrate 100 is shown, the embodiments of the present invention may include multiple first first build-up structures Or the second build-up structure, or only include one or more first build-up structures, or only include one or more second build-up structures. According to some embodiments of the present invention, according to the design or requirement of the product, the area of the patch antenna on the sidewall of the core substrate and/or the dielectric layer can be adjusted by using the build-up structure to achieve the desired frequency performance. In addition, not both patch antennas in the patch antenna pair need to include antenna build-up layers. For example, in the patch antenna pair A1 in FIG. 1B , only one patch antenna may include antenna build-up layers.

15, 16A-18A, 16B-18B, 19, 20A-21A, and 20B-21B are schematic diagrams illustrating a process for forming the antenna structure 20 according to other embodiments of the present invention. Referring first to FIG. 15 , a core substrate 100 is provided. The core substrate 100 has a first antenna layer 101 above its top surface and a second antenna layer 102 below its bottom surface. Next, as shown in Figures 16A and 16B (Figure 16A shows a cross-sectional view of the antenna structure 20, Figure 16B is a top view of the antenna structure 20, and the A-A section in Figure 16B may correspond to Figure 16A), on the core substrate 100 An opening OP5 and an opening OP6 passing through the first antenna layer 101 , the core substrate 100 , and the second antenna layer 102 are formed on opposite sides of each other. In some embodiments, the process of forming the opening OP5 and the opening OP6 includes a shape cutting process (or called a scooping process).

Then with reference to Figures 17A, 17B, 18A and 18B, Figures 17A and 18A are cross-sectional views of the antenna structure 20, Figures 17B and 18B are top views of the antenna structure 20, and the A-A cross-sections can correspond to the 17A and 18A respectively picture. In FIGS. 17A and 17B , the third antenna layer 103 is formed on the sidewalls of the opening OP5 and the second opening OP6 , on the top surface of the first antenna layer 101 , and under the bottom surface of the second antenna layer 102 . In some embodiments, the process of forming the third antenna layer 103 may include using an electroplating process. Then referring to Figures 18A and 18B, the first antenna layer 101, the second antenna layer 102, and the third antenna layer 103 are patterned to expose the core substrate 100, and leave adjacent to the first opening OP5 and the second opening OP6 the first antenna layer 101 , the second antenna layer 102 , and the third antenna layer 103 , and leave the third antenna layer 103 on the sidewalls of the first opening OP5 and the second opening OP6 . In some embodiments, the process of patterning the first antenna layer 101, the second antenna layer 102, and the third antenna layer 103 may include forming a patterned mask on the first antenna layer 103, and then using an etching process to remove Part of the first antenna layer 103 is removed to expose part of the first antenna layer 101 and the second antenna layer 102, and then another etching process is used to remove the exposed part of the first antenna layer 101 and the second antenna layer 102. In an embodiment where the first antenna layer 101 , the second antenna layer 102 , and the third antenna layer 103 comprise the same material, the patterning process can be performed in the same etching process. The foregoing etching process may include a wet etching process, wherein the etchant used includes sulfuric acid-hydrogen peroxide solution, sodium chlorate solution, or other suitable solutions.

Referring to FIG. 19 , a cutting process is performed on the core substrate 100 , the first antenna layer 101 , the second antenna layer 102 and the third antenna layer 103 along the circular path P. Referring to FIG. Figures 20A and 20B illustrate the antenna structure 20 after the cutting process, Figure 20A is a cross-sectional view, Figure 20B is a top view, and the A-A cross-section may correspond to Figure 20A. After cutting, the first antenna layer 101, the second antenna layer 102, and the third antenna layer 103 in the loop path P are formed on the surfaces of a pair of notches N on opposite sidewalls of the core substrate 100 in the loop path P A pair of patch antennas. In some embodiments, the patch antenna pair is conformably disposed on the surface of the notch N. The notch N can be a rectangle, a semicircle, a partial ellipse, a polygon with partial corners having radians, or other shapes. As shown in FIG. 20B , the pair of notches N are oppositely disposed and the core substrate 100 between the pair of patch antennas is a cavity C that does not contain conductive material. The embodiment of the present invention also includes forming multiple antenna structures at the same time. These antenna structures can be formed using a process similar to the above, and a cutting process is performed to form patch antennas recessed in the core substrates of these antenna structures. In some embodiments, similar to FIG. 9B, the circular path P in FIG. 19 can also be composed of multiple cutting paths.

In some embodiments, a solder resist layer 110 may be formed to cover the top and bottom surfaces of the core substrate 100, the third antenna layer 103, and the exposed first antenna layer 101 and the second antenna before performing the cutting process. The sidewalls of layer 102 are shown in Figure 21A. For example, coating or dry film lamination may be performed to form the solder resist layer 110 . After the solder resist layer 110 is formed, a cutting process can be performed to form the antenna structure 20 as shown in FIG. 21B. In some embodiments, the first antenna layer 101 , the second antenna layer 102 , and the third antenna layer 103 of the antenna structure 20 include the same material. In some embodiments, the first antenna layer 101 and the second antenna layer 102 of the antenna structure 20 shown in FIG. Layer structure process to form a first build-up structure on the core substrate 100 of the antenna structure 20 and form a second build-up structure under the bottom surface of the core substrate 100 of the antenna structure 20, and then perform a patterning process (such as a shape cutting process ) to form openings, the openings pass through the first and second build-up structures (including dielectrics and build-up antennas), the first antenna layer 101, the core substrate 100, and the second antenna layer 102, and then form the third antenna Layer 103 is on the sidewall of the opening, above the first build-up structure, and below the second build-up structure, and then pattern the third antenna layer 103 and continue the cutting process to form a patch as shown in Figures 3A and 3B Antenna pair A6. In some other embodiments, the antenna structure 10 shown in FIG. 14 can be patterned (for example, shaped and cut) to form the fifth antenna layer 105, the third antenna layer 103, the second antenna layer 102, And the opening of the seventh antenna layer 107, and leave part of the fifth antenna layer 105, the third antenna layer 103, the second antenna layer 102, and the seventh antenna layer 107 on the sidewall of the opening, and then perform cutting The manufacturing process can also form the patch antenna pair A6 as shown in FIGS. 3A and 3B. In other embodiments, before performing the cutting process, the surface of the patch antenna can be treated, for example, electroplating is performed to form nickel, palladium, or gold on the surface of the patch antenna. In an embodiment where the surface of the patch antenna is processed, a cutting process may be performed after the processing without forming a solder mask.

In some embodiments, one antenna of the antenna pair can be configured as an antenna plane, and the other antenna can be configured as a ground plane, and the cavity between the antenna pair serves as an insulator and a resonant cavity. Although the above embodiments are described with a patch antenna, the embodiments of the present invention can also be applied to other antennas, such as micro-strip antennas.

The antenna structure and its forming method provided by the embodiments of the present invention include forming a pair of patch antennas on the side wall of the core substrate, which can improve the alignment accuracy between the pair of patch antennas and control the space between the pair of patch antennas. cavity distance (or cavity thickness) to achieve the desired frequency performance. For example, according to design requirements, the cavity distance between the patch antenna pairs can be increased to improve performance. In addition, the method for forming the antenna structure provided by the embodiment of the present invention can also reduce the cost of the manufacturing process.

The features of several embodiments are summarized above, so that those skilled in the art of the present invention can better understand various aspects of the present invention. Those who have ordinary knowledge in the technical field of the present invention should understand that they can easily use the present invention as a basis to design or modify other processes and structures to achieve the same purpose and/or advantages as the embodiments described herein . Those with ordinary knowledge in the technical field of the present invention should also understand that such equivalent structures do not depart from the spirit and scope of the present invention, and that various changes, substitutions, and substitutions can be made here without departing from the present invention. spirit and scope.

10,20: antenna structure 100: core substrate 110: solder mask layer 101: first antenna layer 102: second antenna layer 103: third antenna layer 104: fourth antenna layer 105: fifth antenna layer 106: second antenna layer Six antenna layers 107: seventh antenna layer 111: first dielectric layer 112: second dielectric layer 116: connectors A1, A2, A3, A4, A5, A6: patch antenna pairs C, C1, C2, C6: Cavity D: Distance D1, D2, D3: Direction N: Notch OP, OP1, OP2, OP3, OP4, OP5, OP6: Opening P: Ring path P _H1 , P _H2 , P _H3 , P _V1 , P _V2 ,P _V3 : cutting path S: main surface

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be noted that, in accordance with the standard practice in the industry, the various features are not drawn to scale and are used for illustrative purposes only. In fact, the dimensions of the elements may be arbitrarily expanded or reduced to clearly illustrate the features of the embodiments of the invention. 1A and 2 are perspective views illustrating antenna structures according to some embodiments of the present invention. FIG. 1B is a top view illustrating an antenna structure according to some embodiments of the present invention. FIG. 3A is a perspective view illustrating an antenna structure according to other embodiments of the present invention. FIG. 3B is a top view illustrating an antenna structure according to other embodiments of the present invention. Figures 4, 5, 6A-8A and 10A are cross-sectional schematic diagrams illustrating a process for forming an antenna structure according to some embodiments of the present invention. Figures 6B-8B, 9A, 9B and 10B are top views illustrating processes for forming antenna structures according to some embodiments of the present invention. 11-14 are schematic cross-sectional views illustrating a process for forming an antenna structure according to some embodiments of the present invention. Figures 15, 16A-18A and 20A-21A are schematic cross-sectional views showing the process of forming the antenna structure according to other embodiments of the present invention. 16B-18B, 19 and 20B are top views illustrating the manufacturing process of the antenna structure according to other embodiments of the present invention. FIG. 21B is a perspective view illustrating an antenna structure according to other embodiments of the present invention.

10: Antenna structure

100: core substrate

110: Solder mask

111: the first dielectric layer

112: second dielectric layer

A1, A2, A3: patch antenna pair

D1, D2, D3: direction

S: main surface

Claims (20)

An antenna structure comprising: a core substrate; and A pair of patch antennas are oppositely disposed on opposite side walls of the core substrate, and the core substrate between the pair of patch antennas is a cavity that does not contain conductive materials. The antenna structure according to claim 1, wherein the pair of patch antennas are embedded in opposite sidewalls of the core substrate, and the sidewalls of each of the pair of patch antennas are coplanar with the sidewalls of the core substrate. The antenna structure as claimed in claim 1, wherein the core substrate has a pair of oppositely disposed notches on the opposite side walls, the pair of notches penetrate the core substrate, wherein the pair of patch antennas are respectively arranged on the core substrate exposed by the pair of notches on the side wall. The antenna structure according to claim 1, wherein at least one patch antenna in the pair of patch antennas extends along a direction perpendicular to the main surface of the core substrate to be higher than the top surface of the core substrate. The antenna structure according to claim 4 further includes a solder resist layer covering the top surface of the core substrate and the top surface of the at least one patch antenna. The antenna structure according to claim 5 further includes a plurality of connectors disposed on the solder resist layer. The antenna structure according to claim 1, wherein at least one patch antenna in the pair of patch antennas extends along a direction perpendicular to the main surface of the core substrate to be lower than the bottom surface of the core substrate. The antenna structure according to claim 7 further includes a solder resist layer covering the bottom surface of the core substrate and the bottom surface of the at least one patch antenna. The antenna structure according to claim 1 further includes a build-up structure disposed above the top surface or below the bottom surface of the core substrate. The antenna structure according to claim 9, wherein the build-up structure includes a dielectric layer and an antenna build-up layer. A method for forming an antenna structure, comprising: providing a core substrate with a first antenna layer above its top surface and a second antenna layer below its bottom surface; patterning the first antenna layer and the core substrate to form a first opening and a second opening exposing the second antenna layer, wherein the first opening and the second opening are located on opposite sides of the core substrate side; filling a third antenna layer into the first opening and the second opening; patterning the first antenna layer and the second antenna layer to expose the core substrate and leave the first antenna layer and the third antenna layer surrounding the third antenna layer and part of the core substrate below the second antenna layer; and performing a cutting process on the core substrate, the first antenna layer, the second antenna layer and the third antenna layer along a circular path, wherein After the dicing process, the first antenna layer, the second antenna layer, and the third antenna layer within the loop path form a pair of patch antennas embedded in opposite sidewalls of the core substrate within the loop path , the pair of patch antennas are arranged opposite to each other and the core substrate between the pair of patch antennas is a cavity that does not contain conductive material. The method for forming an antenna structure according to claim 11, further comprising forming a first build-up structure on the core substrate after patterning the first antenna layer and the second antenna layer and before performing the cutting process On the top surface, the first build-up structure includes a first dielectric layer and a first antenna build-up layer, wherein a portion of the first antenna build-up layer passes through the first dielectric layer and connects to the third antenna Floor. The method for forming an antenna structure according to claim 12, wherein the cutting process further includes cutting the first build-up structure along the circular path, wherein After the dicing process, the first antenna layer, the second antenna layer, the third antenna layer, and the first antenna build-up layer within the loop path form at least one of the pair of patch antennas A patch antenna. The method for forming the antenna structure according to claim 12 further includes forming a second build-up structure under the bottom surface of the core substrate, the second build-up structure including a second dielectric layer and a second antenna build-up layer, A part of the second antenna build-up layer passes through the second dielectric layer and connects to the second antenna layer. The method for forming an antenna structure according to claim 14, wherein the cutting process further includes cutting the first build-up structure and the second build-up structure along the circular path, wherein After the dicing process, the first antenna layer, the second antenna layer, the third antenna layer, the first antenna build-up layer, and the second antenna build-up layer within the circular path form the For at least one patch antenna among the patch antennas. The method for forming an antenna structure according to claim 14, wherein the first antenna layer, the second antenna layer, the third antenna layer, the first antenna addition layer, and the second antenna addition layer include the same material, and the core substrate, the first dielectric layer, and the second dielectric layer include the same material. A method for forming an antenna structure, comprising: providing a core substrate with a first antenna layer above its top surface and a second antenna layer below its bottom surface; forming a first opening and a second opening through the first antenna layer, the core substrate, and the second antenna layer, wherein the first opening and the second opening are located on opposite sides of the core substrate ; forming a third antenna layer on the sidewalls of the first opening and the second opening, on the top surface of the first antenna layer, and under the bottom surface of the second antenna layer; patterning the first antenna layer, the second antenna layer, and the third antenna layer to expose the core substrate and leave the first antenna layer, the first antenna layer adjacent to the first opening and the second opening a second antenna layer, and the third antenna layer, leaving the third antenna layer on the sidewalls of the first opening and the second opening; and performing a cutting process on the core substrate, the first antenna layer, the second antenna layer and the third antenna layer along a circular path, wherein After the dicing process, the first antenna layer, the second antenna layer, and the third antenna layer within the circular path are formed in a pair of notches on opposite sidewalls of the core substrate within the circular path. For a pair of patch antennas on the surface, the pair of notches are oppositely arranged, and the core substrate between the pair of patch antennas is a cavity that does not contain conductive materials. The method for forming an antenna structure according to claim 17 further includes forming a build-up structure above or below the top surface of the core substrate, wherein the build-up structure includes a dielectric layer and an antenna build-up layer. The method for forming the antenna structure of claim 17 further includes: Before performing the cutting process, a solder resist layer is formed to cover the top surface and the bottom surface of the core substrate and cover the third antenna layer. The method for forming an antenna structure according to claim 17, wherein the first antenna layer, the second antenna layer, and the third antenna layer comprise the same material.

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