TWI811648B - 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 method of forming the same

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

Electronic devices often include integrated chips with wireless communication components. Generally speaking, integrated chips can use off-chip antennas (i.e., external antennas that are not integrated into the integrated chip) or on-chip antennas (i.e., integrated (or integrated) into Integrated chip antenna) wireless communication components. Antennas used for high-frequency wireless communication components may use patch antennas mounted on high-frequency substrates or high-frequency printed circuit boards.

In recent years, the demand for wireless communications in consumer electronic products (such as smartphones, smart wearable devices, tablets, or car satellite navigation, etc.) has continued to increase, and electronic products are expected to be lighter and thinner. size, and better performance. In some electronic devices using wireless communication components including off-chip antennas, the product size may not be reduced due to the extra volume occupied by the off-chip antennas. For these devices, wireless communication components including on-chip antennas can be used to reduce product size. While existing on-chip antennas generally meet the needs, they are not satisfactory in all aspects.

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 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, which includes: providing a core substrate with a first antenna layer above its top surface and a second antenna layer below its bottom surface. The first antenna layer and the core substrate are patterned to form first openings and second openings exposing the second antenna layer, wherein the first openings and the second openings are located on opposite sides of the core substrate. Fill 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 cutting process, a pair of patch antennas embedded in the opposite side walls of the core substrate in the annular path are formed on the first antenna layer, the second antenna layer, and the third antenna layer in the annular path. This pair of patch antennas is The antennas are arranged oppositely 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 further provides a method for forming an antenna structure, which includes: providing a core substrate with a first antenna layer above the top surface and a second antenna layer below the 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. A 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. The first antenna layer, the second antenna layer, and the third antenna layer are patterned 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, and leave a third antenna layer on the side walls 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 cutting process, the first antenna layer, the second antenna layer, and the third antenna layer in the annular path are formed on the surface of a pair of notches on the opposite side walls of the core substrate in the annular path. Antenna, the pair of notches are arranged oppositely and the core substrate between the pair of patch antennas is a cavity that does not contain conductive material.

The following disclosure provides numerous 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 only examples and are not intended to limit the embodiments of the present invention. For example, if the 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. In addition, embodiments of the present invention may have repeated element symbols in various examples. Such repetition is for the sake of simplicity and clarity and is not intended to represent the relationship between the various embodiments and/or configurations discussed.

In addition, in some embodiments of the present invention, terms related to joining and connecting, such as "connection", "interconnection", etc., unless otherwise defined, may mean that two structures are in direct contact, or may also mean that the two structures are not in direct contact. Direct contact, where other structures are located between the two structures. And the terms about joining and connecting can also include the situation where both structures are movable, or both structures are fixed.

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

The terms "about", "approximately" and "approximately" used in this article 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 values. That is to say, in the absence of specific instructions 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 in which additional steps may be provided before, during and/or after the various stages described in these embodiments. Some of the stages described may be replaced or deleted in different embodiments. The antenna structure of the embodiment of the present invention can add additional components. Some of the components described may be replaced or deleted in different embodiments. Although some of the embodiments discussed are performed in a specific order of steps, the steps may be performed in another logical order.

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

Embodiments of the present invention provide an antenna structure and a method for forming the same. By arranging a pair of patch antennas on the side wall of the substrate of the antenna structure, 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 to improve the accuracy of patch antenna alignment.

Figures 1A, 1B and 2 are schematic diagrams of the antenna structure 10 according to some embodiments of the present invention. Figure 1A shows a perspective view of the antenna structure 10 , and Figure 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, paper phenolic resin, composite epoxy, polyethylene Polyimide resin, glass fiber, other appropriate insulating materials, or a combination of the above.

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 needed, wherein the first dielectric layer 111 may be disposed above the core substrate 100 and the second dielectric layer 112 may Disposed below 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, and each includes: epoxy resin, bismaleimide-triazine resin, polyimide, polyimide, etc. Ajinomoto build-up film (ABF), polyphenylene oxide (PPO), polypropylene (PP), polymethyl methacrylate (PMMA), polytetrafluorethylene (PTFE) ), fiberglass, or other suitable materials. In some embodiments, the first dielectric layer 111 and the second dielectric layer 112 are prepreg materials obtained by pre-impregnating 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 Figure 1B, it should be noted that in order to clearly show the positions of the patch antenna and the core substrate, Figure 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 patch antenna pairs A1 , A2 and A3 are relatively disposed on opposite side walls 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 it does not contain conductive material, and it does not mean that a gap must be formed therein (that is, the cavity may or may not include gaps). Therefore, according to some embodiments of the present invention, the patch antenna is The core substrate between them, which contains no conductive material, is called a "cavity." In further embodiments, a core substrate and a dielectric layer may be included between the patch antenna pairs, which do not contain conductive materials. Therefore, in these embodiments, the core substrate and the dielectric layer between the patch antenna pairs Also a cavity. As shown in FIG. 1B , the patch antenna pairs A1 , A2 and A3 are embedded in opposite side walls of the core substrate 100 , and one side wall of the patch antenna is coplanar with one side wall of the core substrate 100 . The materials 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 foregoing materials. As described below in the process of forming an antenna structure, embodiments of the present invention can simultaneously form a pair of patch antennas to improve the alignment accuracy of the pair of patch antennas, and the cavity between the pairs 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 pair of patch antennas may extend higher than the top surface of the core substrate 100 . For example, as shown in FIG. 1A , one of the patch antenna pairs A1 extends higher than the top surface of the core substrate 100 along the direction D3 perpendicular to the main surface S of the core substrate 100 . In some embodiments, at least one patch antenna in the pair of patch antennas may extend below the bottom surface of the core substrate 100 . For example, as shown in FIG. 1A , one of the patch antenna pairs A2 extends below the bottom surface of the core substrate 100 along the direction D3 perpendicular to the main surface S of the core substrate 100 . According to some embodiments of the present invention, the patch antenna pairs A1, A2 and A3 may also be embedded in the sidewalls of the first dielectric layer 111 and the second dielectric layer 112, and the patch antenna pairs may also extend along the direction D3 to be higher than the first dielectric layer 111 and the second dielectric layer 112. A patch antenna with a 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 Figure 1B, the patch antenna pair can be rectangular, partially elliptical, polygonal with some corners having arcs, 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 can be called a build-up layer structure. Similarly, the second dielectric layer 112 and the embedded antenna layer 112 can be called a build-up structure. The antenna build-up layer can also be called a build-up layer structure. The build-up structure may be disposed above or below the core substrate 100 . According to the application and design requirements of the product, the layered structure can be used to adjust the size of the patch antenna, 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 mask 110 covering the top surfaces of the antenna patch pairs A1 and A3 and the first dielectric layer 111 . The antenna structure 10 may also include a solder mask layer 110 covering the bottom surfaces of the antenna patch pairs A1, A2, A3 and the second dielectric layer 112. In some embodiments, the solder mask layer 110 may be a photosensitive material (such as an ultraviolet photosensitive material), a heat-sensitive material (such as a thermosetting heat-sensitive material), other appropriate materials, or a combination of the foregoing. For example, the solder mask layer 110 may include: epoxy resin, urethane, ethyl ester resin, or other materials.

Referring to FIG. 2 , the antenna structure 10 may further include a plurality of connectors 116 disposed on the solder mask layer 110 . The connector 116 can be used to transmit signals. The material of connector 116 may include metallic materials such as tin or nickel. As shown in Figure 2, depending on product characteristics, in the embodiment including the first dielectric layer 111 and the second dielectric layer 112, the patch antenna can only extend higher than the first dielectric layer 111 but not extend lower than the first dielectric layer 111 and the second dielectric layer 112. In the second dielectric layer 112, such as the patch antenna pair A5 shown in Figure 2; or the patch antenna may only extend above the top surface of the core substrate 100 and below the bottom surface of the core substrate 100, but does not extend above The first dielectric layer 111 is lower than the second dielectric layer 112, such as the patch antenna pair A4 shown in Figure 2.

Figures 3A and 3B are schematic diagrams of the antenna structure 20 according to other embodiments of the present invention, in which components similar to the antenna structure 10 are labeled with the same symbols, and the relevant description will not be 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 oppositely arranged notches N on the opposite side walls. The pair of notches N penetrate the core substrate 100, and the pair of patch antennas A6 are respectively disposed on the side walls 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 compliantly disposed along the notch N, so the patch antenna pair A6 is recessed in the side wall of the core substrate 100 . In some embodiments, the patch antenna pair A6 may 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 patch antenna pair A6 may 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 exposed parts of the notch N. /or on the sidewalls of the second dielectric layer 112, and recessed in the sidewalls of the first dielectric layer 111 and/or the second dielectric layer 112. The patch antenna pair A6 may extend 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 Figure 3A is only exemplary. The present disclosure can also dispose multiple pairs of patch antennas on the core substrate 100 and the first core substrate 100 of the antenna structure 20 respectively. Multiple pairs of notches on the sidewalls of the dielectric layer 111 and/or the second dielectric layer 112, and the multiple pairs of notches can also be provided on another pair of opposite sidewalls of the core substrate 100, or on the core substrate 100 or the first dielectric layer. 111 and the other pair of opposite sidewalls of the second dielectric layer 112 .

Figures 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 Figure 4, a core substrate 100 is provided. The core substrate 100 has a first antenna layer 101 above the top surface and a second antenna layer 102 below the bottom surface. Then, as shown in Figures 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. Figures 5 and 6A illustrate cross-sectional views of the patterned antenna structure 10, and Figure 6B is a top view of the antenna structure 10, where the A-A section in Figure 6B can correspond to Figure 6A. As shown in Figure 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. To form the opening OP1 and the opening OP2 exposing the second antenna layer 102, 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, the patterned mask is then removed. The first antenna layer 101 and the second antenna layer 102 may include the same or different materials. For example, they may respectively include: copper, aluminum, tungsten, silver, gold, or a combination of the foregoing materials. The patterned mask may include: dry film, liquid photoresist, other appropriate materials, or a combination of the foregoing. In an embodiment in which the material of the first antenna layer 101 includes copper, the etching process may include a wet etching process, in which the etchant used 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.

Next, refer 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. The A-A sections may correspond to Figures 7A and 8A respectively. Figure. In Figures 7A and 7B, the third antenna layer 103 is filled into the opening OP1 and the opening OP2. The material of the third antenna layer 103 may be the same as the material 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 Figures 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, leaving the first antenna layer 101 surrounding the third antenna layer 103 and leaving the third antenna layer 103 and part of the core substrate 100 underneath. Line layer 102.

Referring to Figure 9A, the cutting process is performed along the circular path P. 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 circular path P may also be composed of multiple cutting paths. Figure 9B also shows multiple antenna structures. These antenna structures can be formed using a process similar to the above, which can include forming multiple openings at the same time and then forming antenna layers in these openings at the same time, and performing cutting paths P The cutting process of _V1 , _PV2 and _PV3 and the cutting paths _PH1 , _PH2 and _PH3 forms the antenna structure 10 as shown in Figure 1A. As shown in Figure 9B, the circular path P may include two cutting paths _PH1 and _PH2 and two other cutting paths _PV1 and _PV2 perpendicular to the two cutting paths _PH1 and _PH2 . In other embodiments, according to design and/or process requirements, the circular path P may be circular, elliptical, rectangular, rhombus, or other suitable shapes.

Figures 10A and 10B illustrate the antenna structure 10 after the cutting process. Figure 10A is a cross-sectional view, and Figure 10B is a top view. The A-A section may correspond to Figure 10A. The first antenna layer 101, the second antenna layer 102 and the third antenna layer 103 in the circular path P form a pair of patch antennas embedded in the opposite side walls of the core substrate 100 in the circular path P. This pair of patch antennas The core substrate 100 disposed oppositely between the pair of patch antennas is a cavity C that does not contain conductive material. 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 pairs of the present disclosure can be formed in the openings (such as openings OP1 and OP2, see Figure 6B) formed by the same process, which can improve the alignment accuracy between the patch antenna pairs, for example Specifically, compared with conventional non-simultaneously formed patch antenna pairs disposed on a substrate, the alignment accuracy can be improved by about 30%. In addition, since the cavity distance (or cavity thickness) between the conventional patch antenna pairs is determined by the multi-layer materials between the patch antenna pairs, the process of forming the multi-layer materials may affect the uniformity of the multi-layer materials, resulting in cavities. The distance is not easy to control and the cavity distance is limited by the number of layers of multi-layer materials. In some embodiments of the present invention, the cavity distance between the patch antennas (such as cavity C, refer to Figure 10B) can be the oppositely arranged antenna layer (such as the first antenna layer) after the patterning and cutting process. 101, refer to 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 of the antenna structure after the cutting process. cavity distance to achieve the desired frequency performance. In addition, since embodiments of the present invention do not require adding additional material layers to increase the cavity distance, manufacturing costs can be reduced.

11-14 are schematic cross-sectional views of a build-up structure forming an antenna structure 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 cutting 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 simultaneously, that is, layers are added above and below the antenna structure 10 at the same time. Referring to Figure 11, a first dielectric layer 111 is formed on the top surface 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 The second dielectric layer 112 is formed under the second antenna layer 102 and the bottom surface of the core substrate 100 and the 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 laminated to the first antenna layer 101, the third antenna layer 103 and the top surface of 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 laminated to the second Under the antenna layer 102 and the bottom surface of 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, 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 openings 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 of patterning the fourth antenna layer 104, the first dielectric layer 111 and the sixth antenna layer 106 and the second dielectric layer 112 may be similar to the process described above with respect to Figures 5, 6A and 6B.

Then, the fifth antenna layer 105 is filled into the opening OP3 and the seventh antenna layer 107 is filled 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 process of filling the third antenna layer 103 into the openings OP1 and OP2 in FIGS. 7A and 7B . The fourth antenna layer 104 and the sixth antenna layer 106 are then patterned to expose the first dielectric layer 111 and the second dielectric layer 112, leaving the fourth antenna layer 104 surrounding the fifth antenna layer 105 and surrounding The sixth antenna layer 106 of the seventh antenna layer 107 is as shown in FIG. 14 . Thus, a first build-up structure including the first dielectric layer 111, the fourth antenna layer 104 and the fifth antenna layer 105 and a second layer structure including the second dielectric layer 112, the sixth antenna layer 106 and the seventh antenna layer 107 are formed. The second build-up layer structure, in which the fourth antenna layer 104 and the fifth antenna layer 105 can be collectively called the first antenna build-up layer, and the sixth antenna layer 106 and the seventh antenna layer 107 can be collectively called the second antenna build-up layer. layer. In some embodiments, after forming the build-up structure, a cutting process as shown in FIG. 9A may be performed to cut the core substrate 100, the first antenna layer 101, the second antenna layer 102, the third antenna layer 103, The first build-up layer structure and the second build-up layer structure. After this 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 a patch antenna A1 or A3 as shown in Figure 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 include 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 when adding layers. For example, when forming the first build-up structure, only the first dielectric layer 111 is formed, and when forming the second build-up structure, the second dielectric layer 112 and the second antenna build-up layer are formed. In these embodiments, after forming the build-up structure, a cutting process as shown in Figure 9A can be performed. After cutting, the antenna layer and the second antenna build-up layer in the circular path P are formed as shown in Figure 1A Patch antenna A2. Similarly, when forming the first build-up structure, the first dielectric layer 111 and the first antenna build-up layer are formed, and when forming the second build-up structure, only the second dielectric layer 112 is formed. After the cutting process, the A patch antenna A5 as shown in Figure 2 is formed. 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 first and then the second build-up structure, or vice versa.

Although in the above 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, embodiments of the present invention may include multiple first build-up structures. or a second build-up structure, which may also include only one or more first build-up structures, or only one or more second build-up structures. According to some embodiments of the present invention, according to the design or requirements of the product, the layered structure can be used to adjust the area of the patch antenna on the sidewalls of the core substrate and/or the dielectric layer to achieve the desired frequency performance. In addition, not both patch antennas in the patch antenna pair need to include antenna enhancement layers. For example, in the patch antenna pair A1 in Figure 1B, only one patch antenna may include antenna enhancement layers.

Figures 15, 16A-18A, 16B-18B, 19, 20A-21A, and 20B-21B are schematic diagrams illustrating a process of forming the antenna structure 20 according to other embodiments of the present invention. First, referring to Figure 15, a core substrate 100 is provided. The core substrate 100 has a first antenna layer 101 above the top surface and a second antenna layer 102 below the bottom surface. Then, 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 can correspond to Figure 16A), on the core substrate 100 The opening OP5 and the 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 the first antenna layer 101, the core substrate 100, and the second antenna layer 102. In some embodiments, the process of forming the openings OP5 and OP6 includes a forming and cutting process (also known as a trough process).

Next, refer 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. The A-A sections may correspond to Figures 17A and 18A respectively. Figure. In Figures 17A and 17B, the third antenna layer 103 is formed on the side walls 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. Next, 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 first openings OP5 and second openings OP6. The first antenna layer 101, the second antenna layer 102, and the third antenna layer 103 are removed, and the third antenna layer 103 is left on the side walls 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 the patterned mask. Remove part of the first antenna layer 103 to expose part of the first antenna layer 101 and the second antenna layer 102, and then use another etching process to remove the exposed parts of the first antenna layer 101 and the second antenna layer. 102. In embodiments where the first antenna layer 101, the second antenna layer 102, and the third antenna layer 103 include the same material, the patterning process can be completed in the same etching process. The aforementioned etching process may include a wet etching process, in which the etchants used include: 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. Figures 20A and 20B illustrate the antenna structure 20 after the cutting process. Figure 20A is a cross-sectional view, and Figure 20B is a top view. The A-A 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 annular path P are formed on the surface of a pair of notches N on the opposite side walls of the core substrate 100 in the annular path P. A pair of patch antennas. In some embodiments, the patch antenna pair is compliantly disposed on the surface of the notch N. The notch N may be a rectangle, a semicircle, a partial ellipse, a polygon with some corners having arcs, or other shapes. As shown in Figure 20B, the pair of notches N are arranged oppositely and the core substrate 100 between the pair of patch antennas is a cavity C that does not contain conductive material. Embodiments of the present invention also include 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 a patch antenna recessed in the core substrate of these antenna structures. In some embodiments, similar to Figure 9B, the circular path P in Figure 19 can also be composed of multiple cutting paths.

In some embodiments, before performing the cutting process, a solder mask layer 110 can 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. The side walls of layer 102 are shown in Figure 21A. For example, coating or dry film lamination may be performed to form the solder mask 110 . After the solder mask 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. 15 can be patterned to perform a patterning process to expose the substrate 100, and then a similar formation process similar to the above is performed on the antenna structure 20. A process of layer structure to form a first build-up structure on the core substrate 100 of the antenna structure 20 and 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 forming and cutting process) ) to form openings that penetrate 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 a third antenna Layer 103 is formed on the sidewall of the opening, above the first build-up structure, and below the second build-up structure, and then patterning the third antenna layer 103 and continuing the cutting process to form a patch as shown in Figures 3A and 3B Antenna pair A6. In other embodiments, the antenna structure 10 shown in FIG. 14 can be subjected to a patterning process (such as a forming and cutting process) 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, leaving parts of the fifth antenna layer 105, the third antenna layer 103, the second antenna layer 102, and the seventh antenna layer 107 on the side walls of the opening, and then perform cutting The process can also form the patch antenna pair A6 as shown in Figures 3A and 3B. In other embodiments, before performing the cutting process, the surface of the patch antenna may be processed, such as performing electroplating to form nickel, palladium, or gold on the surface of the patch antenna. In the embodiment where the surface of the patch antenna is treated, a cutting process can be performed without forming a solder mask after the treatment.

In some embodiments, one antenna in 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 pairs serves as an insulator and resonant cavity. Although the above-mentioned embodiments are described as patch antennas, embodiments of the present invention can also be applied to other antennas, such as micro-strip antennas.

The antenna structure and its formation method provided by embodiments of the present invention include forming a pair of patch antennas on the side wall of a core substrate, which can improve the alignment accuracy between the pairs of patch antennas and control the space between the pairs of patch antennas. cavity distance (or cavity thickness) to achieve the desired frequency performance. For example, the cavity distance between patch antenna pairs can be increased according to design requirements 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 with ordinary skill in the technical field to which the present invention belongs can better understand various aspects of the present invention. Those with ordinary skill in the technical field to which the present invention belongs 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 purposes and/or advantages as the embodiments introduced herein. . Those with ordinary skill in the technical field to which the present invention belongs should also understand that such equivalent structures do not deviate from the spirit and scope of the present invention, and that various changes, substitutions, and replacements can be made thereto without departing from the spirit and scope of the present invention. spirit and scope.

10,20: Antenna structure 100: Core substrate 110: Solder mask 101: First antenna layer 102: Second antenna layer 103: Third antenna layer 104: Fourth antenna layer 105: Fifth antenna layer 106: 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: Circular path P _H1 , P _H2 , P _H3 , P _V1 , P _V2 ,P _V3 : cutting path S: main surface

The 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 standard practice in the industry, various features are not drawn to scale and are for illustrative purposes only. In fact, the dimensions of the elements may be arbitrarily enlarged or reduced in order to clearly illustrate the features of the embodiments of the invention. Figures 1A and 2 are perspective views of antenna structures according to some embodiments of the present invention. Figure 1B is a top view of an antenna structure according to some embodiments of the present invention. Figure 3A is a perspective view of an antenna structure according to other embodiments of the present invention. Figure 3B is a top view of an antenna structure according to other embodiments of the present invention. Figures 4, 5, 6A-8A and 10A are schematic cross-sectional views illustrating a process of forming an antenna structure according to some embodiments of the present invention. 6B-8B, 9A, 9B and 10B are top views illustrating a process of forming an antenna structure according to some embodiments of the present invention. 11-14 are schematic cross-sectional views illustrating a process of forming an antenna structure according to some embodiments of the present invention. Figures 15, 16A-18A and 20A-21A are schematic cross-sectional views illustrating a process of forming an antenna structure according to other embodiments of the present invention. Figures 16B-18B, 19 and 20B are top views illustrating the manufacturing process of the antenna structure according to other embodiments of the present invention. Figure 21B is a perspective view of an antenna structure according to other embodiments of the present invention.

10: Antenna structure

100:Core substrate

110: Solder mask

111: First dielectric layer

112: Second dielectric layer

A1, A2, A3: Patch antenna pair

D1, D2, D3: direction

S: main surface

Claims (19)

An antenna structure includes: a core substrate; a pair of patch antennas (patch antennas) arranged on opposite side walls of the core substrate, and the core substrate between the pair of patch antennas is an empty space that does not contain conductive materials. a cavity; and a build-up structure disposed above the top surface or below the bottom surface of the core substrate. The antenna structure of claim 1, wherein the pair of patch antennas are embedded in opposite side walls of the core substrate, and a side wall of each of the pair of patch antennas is coplanar with the side wall of the core substrate. The antenna structure of claim 1, wherein the opposite side walls of the core substrate have a pair of oppositely arranged notches, the pair of notches penetrate the core substrate, and the pair of patch antennas are respectively disposed on the core substrate exposed by the pair of notches. on the side wall. The antenna structure of claim 1, wherein at least one of the pair of patch antennas extends in 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 of claim 4 further includes a solder mask covering the top surface of the core substrate and the top surface of the at least one patch antenna. The antenna structure of claim 5 further includes a plurality of connectors disposed on the solder mask layer. The antenna structure of claim 1, wherein at least one of the pair of patch antennas extends in a direction perpendicular to the main surface of the core substrate to below the The bottom surface of the core substrate. The antenna structure of claim 7 further includes a solder mask covering the bottom surface of the core substrate and the bottom surface of the at least one patch antenna. The antenna structure of claim 1, wherein the build-up layer structure includes a dielectric layer and an antenna build-up layer. A method of forming an antenna structure, including: providing a core substrate with a first antenna layer above the top surface and a second antenna layer below the 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; fill a third antenna layer into the first opening and in the second opening; pattern 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 a portion of the second antenna layer under the core substrate; and perform a cutting process along a circular path on the core substrate, the first antenna layer, the second antenna layer and the third antenna layer, wherein After the cutting process, the first antenna layer, the second antenna layer and the third antenna layer in the annular path form a pair of patch antennas embedded in the opposite side walls of the core substrate in the annular path , the pair of patch antennas are arranged oppositely 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 as claimed in claim 10, wherein in the pattern After forming the first antenna layer and the second antenna layer and before performing the cutting process, it further includes forming a first build-up layer structure on the top surface of the core substrate, the first build-up layer structure including a first A dielectric layer and a first antenna build-up layer, wherein a part of the first antenna build-up layer passes through the first dielectric layer and connects to the third antenna layer. The method of forming an antenna structure as claimed in claim 11, wherein the cutting process further includes cutting the first build-up structure along the circular path, wherein after the cutting process, the first antenna layer in the circular path , the second antenna layer, the third antenna layer, and the first antenna build-up layer form at least one patch antenna in the pair of patch antennas. The method of forming the antenna structure of claim 11 further includes forming a second build-up layer structure under the bottom surface of the core substrate, the second build-up layer structure including a second dielectric layer and a second antenna build-up layer, A portion of the second antenna build-up layer passes through the second dielectric layer and is connected to the second antenna layer. The method of forming an antenna structure as claimed in claim 13, 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 cutting process, within the circular path 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 form at least one patch antenna in the pair of patch antennas. The method of forming an antenna structure as claimed in claim 13, wherein 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 include the same material, and the core substrate, the first dielectric layer, and the The second dielectric layer includes the same material. A method of forming an antenna structure, including: providing a core substrate with a first antenna layer above the top surface and a second antenna layer below the bottom surface; forming through the first antenna layer, the core substrate, and a first opening and a second opening of 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 at the first opening and the second opening Patterning the first antenna layer, the second antenna layer, and the third antenna on the sidewalls of the second opening, on the top surface of the first antenna layer, and under the bottom surface of the second antenna layer 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, and leave the first opening and the third antenna layer on the sidewall of the second opening; and performing a cutting process along a circular path on the core substrate, the first antenna layer, the second antenna layer and the third antenna layer, After the cutting process, the first antenna layer, the second antenna layer, and the third antenna layer in the annular path form a pair of gaps on the opposite side walls of the core substrate in the annular path. There is a pair of patch antennas on the surface, the pair of notches are arranged oppositely, and the core substrate between the pair of patch antennas is a cavity that does not contain conductive material. The method of forming the antenna structure of claim 16 further includes forming a build-up structure above the top surface or below the bottom surface of the core substrate, wherein the build-up structure includes a dielectric layer and an antenna build-up layer. The method of forming the antenna structure of claim 16 further includes: before performing the cutting process, forming a solder resist layer to cover the top and bottom surfaces of the core substrate and cover the third antenna layer. The method of forming an antenna structure as claimed in claim 16, wherein the first antenna layer, the second antenna layer, and the third antenna layer comprise the same material.

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