Patent Publication Number: US-2023140354-A1

Title: Millimeter-wave antenna module package structure and manufacturing method thereof

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the priority benefits of U.S. provisional application serial no. 63/275,914, filed on Nov. 4, 2021 and Taiwanese application serial 111141455, filed on Oct. 31, 2022. The entirety of each of the above-mentioned patent applications is hereby incorporated by reference herein and made a part of this specification. 
    
    
     BACKGROUND 
     Technical Field 
     The disclosure relates to a millimeter-wave antenna module package structure and a manufacturing method thereof. 
     Description of Related Art 
     During packaging of a high-frequency antenna, a distance between a transmitting end and a receiving end thereof and a radio frequency integrated circuit (RFIC) is required to be optimized, and a surface roughness of a transmission copper wire thereof is also required to be relatively smooth. The distance between the antenna and the integrated circuit (IC) cannot be precisely controlled if a conventional PC (polycarbonate) board (circuit board) process is used. In addition, during an etching process of manufacturing the PC board, the surface of the transmission copper wire may be roughened. These may reduce an efficiency of a high-frequency antenna. 
     SUMMARY 
     The disclosure provides a millimeter-wave antenna module package structure and a manufacturing method thereof, in which a relatively high efficiency of a high-frequency antenna can be achieved while a multi-layer redistribution structure is provided. 
     In an embodiment of the disclosure, a millimeter wave module antenna package structure includes a first group of circuit structure, a second group of circuit structure, and a plurality of joints. The first group of circuit structure includes at least one first circuit layer and a plurality of first conductive connectors. The at least one first circuit layer includes an antenna pattern. The second group of circuit structure includes a plurality of second circuit layers and a plurality of second conductive connectors. The plurality of joints are disposed between the first group of circuit structure and the second group of circuit structure. The joints connect the first conductive connectors and the second conductive connectors to electrically connect the first group of circuit structure to the second group of circuit structure to form a multi-layer redistribution structure. 
     In an embodiment of the disclosure, each of the at least one first circuit layer includes a plurality of first conductive vias, and each of the second circuit layers includes a plurality of second conductive vias. A direction in which the first conductive vias taper is opposite to a direction in which the second conductive vias taper. 
     In an embodiment of the disclosure, the millimeter-wave antenna module package structure further includes an underfill. The underfill fills at least part of a gap between the joints, the first group of circuit structure, and the second group of circuit structure. 
     In an embodiment of the disclosure, part of the gap is not filled by the underfill, such that a cavity surrounded by the underfill is formed between the first group of circuit structure and the second group of circuit structure. 
     In an embodiment of the disclosure, the joints are located in the cavity and separated from the underfill. 
     In an embodiment of the disclosure, the gap is filled up. 
     In an embodiment of the disclosure, the millimeter-wave antenna module package structure further includes a first semiconductor device. The first semiconductor device is disposed on the second group of circuit structure and electrically connected to the second group of circuit structure. 
     In an embodiment of the disclosure, the first semiconductor device includes a plurality of first semiconductor devices. A part of the first semiconductor devices is disposed on a surface of the second group of circuit structure, and another part of the first semiconductor devices is disposed on another surface of the second group of circuit structure opposite to the surface. 
     In an embodiment of the disclosure, the millimeter-wave antenna module package structure further includes a second semiconductor device. The second semiconductor device is disposed on the first group of circuit structure and electrically connected to the first group of circuit structure. 
     In an embodiment of the disclosure, a manufacturing method of a millimeter-wave antenna module package structure includes the following. A first group of circuit structure is formed on a first temporary carrier. The first group of circuit structure includes at least one first circuit layer and a plurality of first conductive connectors. The at least one first circuit layer includes an antenna pattern. A second group of circuit structure is formed on a second temporary carrier. The second group of circuit structure includes a plurality of second circuit layers and a plurality of second conductive connectors. The first group of circuit structure and the second group of circuit structure are joined by a plurality of joints. The joints connect the first conductive connectors and the second conductive connectors to electrically connect the first group of circuit structure to the second group of circuit structure to form a multi-layer redistribution structure. 
     In an embodiment of the disclosure, a dielectric layer of the first group of circuit structure is formed by a liquid curing process. 
     In an embodiment of the disclosure, a dielectric layer of the first group of circuit structure is formed by a lamination process. 
     In an embodiment of the disclosure, a metal circuit of the first group of circuit structure is formed by a thin film process. 
     Based on the foregoing, in an embodiment of the disclosure, a plurality of groups of circuit structures are first separately and individually manufactured on the temporary carriers, and then the groups of circuit structures are directly joined and assembled into a multi-layer redistribution structure. As such, compared to continuously manufacturing a multi-layer redistribution structure at one single time, warpage may be effectively reduced, and the distance between the antenna and the IC may be controlled more precisely. Accordingly, in the millimeter-wave antenna module package structure in an embodiment of the disclosure, a relatively high efficiency of a high-frequency antenna may be achieved while the multi-layer redistribution structure is provided. 
     To make the aforementioned more comprehensible, several embodiments accompanied with drawings are described in detail as follows. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings are included to provide a further understanding of the disclosure, and are incorporated in and constitute a part of this specification. The drawings illustrate exemplary embodiments of the disclosure and, together with the description, serve to explain the principles of the disclosure. 
         FIG.  1 A  to  FIG.  1 C  are schematic partial cross-sectional views showing a manufacturing method of a millimeter-wave antenna module package structure according to some embodiments of the disclosure. 
         FIG.  1 D  is a schematic partial cross-sectional view showing an alternative embodiment of  FIG.  1 C . 
         FIG.  2 A  to  FIG.  2 C  are schematic partial cross-sectional views showing a manufacturing method of a millimeter-wave antenna module package structure according to some embodiments of the disclosure. 
         FIG.  3 A  to  FIG.  3 E  are schematic partial cross-sectional views showing a manufacturing method of a millimeter-wave antenna module package structure according to some embodiments of the disclosure. 
         FIG.  3 F  and  FIG.  3 G  are schematic partial cross-sectional views showing millimeter-wave antenna module package structures according to some embodiments of the disclosure. 
         FIG.  4 A  and  FIG.  4 C  are schematic partial cross-sectional views showing alternative embodiments of  FIG.  1 B . 
         FIG.  4 B  is a schematic partial cross-sectional view of a millimeter-wave antenna module package structure formed by the circuit structure of  FIG.  4 A . 
     
    
    
     DESCRIPTION OF THE EMBODIMENTS 
     Exemplary embodiments of the disclosure will be comprehensively described below with reference to the drawings, but the disclosure may also be embodied in various different forms and should not be construed as being limited to the embodiments described herein. In the drawings, sizes, dimensions, or thicknesses of regions, parts, and layers may not be drawn to scale or may be exaggerated for clarity. For ease of understanding, the same or like elements will be labeled with the same or like reference numerals in the following description, and will not be repeated in the following paragraphs. 
     Directional terms (e.g., up, down, right, left, front, back, top, bottom) are only used herein for reference to the drawings and are not intended to imply an absolute orientation. 
     It should be understood that, although terms “first”, “second”, “third”, and so on may be used herein to describe various elements, members, regions, layers, and/or parts, these elements, members, regions, layers, and/or parts should not be limited by these terms. These terms are only used to distinguish one element, member, region, layer, or part from another element, member, region, layer, or part. 
     Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art related to the disclosure. 
       FIG.  1 A  to  FIG.  1 C  are schematic partial cross-sectional views showing a manufacturing method of a millimeter-wave antenna module package structure according to some embodiments of the disclosure.  FIG.  1 D  is a schematic partial cross-sectional view showing an alternative embodiment of  FIG.  1 C . With reference to  FIG.  1 A , a first group of circuit structure  110  is formed on a first temporary carrier  10 . The first temporary carrier  10  may be made of glass, plastic, silicon, metal, or other suitable materials as long as the material can withstand subsequent processes and in the meanwhile carry structures formed thereon. 
     In some embodiments, a first release layer  12  (e.g., a light-to-heat conversion film or other suitable release layers) may optionally be coated between the first temporary carrier  10  and the first group of circuit structure  110  to enhance peelability between the first temporary carrier  10  and the first group of circuit structure  110  during subsequent processes and improve flatness of the first group of circuit structure  110 , but the disclosure is not limited thereto. 
     In this embodiment, the first group of circuit structure  110  includes at least one first circuit layer  111  (one first circuit layer schematically shown in  FIG.  1 A ) and a plurality of first conductive connectors  112 , and may be formed on the first temporary carrier  10 . Each first circuit layer  111  may include an antenna pattern  111   a , a first dielectric layer  111   b , and/or a first conductive via  111   c . Here, the antenna pattern  111   a  and the first conductive via  111   c  may be embedded in the first dielectric layer  111   b , but the disclosure is not limited thereto. 
     In some embodiments, the antenna pattern  111   a  and the first conductive via  111   c  may be metal circuits of the first group of circuit structure  110 , and the metal circuits may be formed by a thin film process. Accordingly, the control of spacing and control of flatness of the copper surface can be effectively improved in an antenna module manufactured by a semiconductor wafer thin film process. As such, the subsequently completed millimeter-wave antenna module package structure may have a thickness and a size less than those made by a PC board process, and is more suitable for the use of mobile communication products, but the disclosure is not limited thereto. 
     In some embodiments, the first dielectric layer  111   b  of the first group of circuit structure  110  is formed by a liquid curing process, and a material thereof is polyimide, for example, but the disclosure is not limited thereto. The first dielectric layer  111   b  of the first group of circuit structure  110  may also be formed by a lamination process, and a material thereof is an Ajinomoto Build-up Film (ABF), for example. 
     In some embodiments, the antenna pattern  111   a  may be formed on the first temporary carrier  10 . The antenna pattern  111   a  may be in direct contact with the first release layer  12 . Next, the first dielectric layer  111   b  including a plurality of openings may be formed on the first temporary carrier  10 . The openings expose at least a part of the antenna pattern  111   a  for electrical connection. Then, a conductive material may be formed in the openings of the first dielectric layer  111   b  to form the first conductive via  111   c . Next, the first conductive connector  112  may be formed using a suitable deposition process. It should be noted that the first group of circuit structure  110  as shown in  FIG.  1 A  is only exemplary, and more layers of the first group of circuit structure  110  may be formed depending on the circuit design requirements. Any form the first group of circuit structure  110  that includes the at least one first circuit layer  111  having the antenna pattern  111   a  and the first conductive connectors  112  shall fall within the scope of the claims following the description. 
     In some embodiments, the materials of the antenna pattern  111   a  and the first conductive via  111   c  may include copper, gold, nickel, aluminum, platinum, tin, a combination thereof, an alloy thereof, or other suitable conductive materials. The material of the first dielectric layer  111   b  may include polyimide (PI), benzocyclobutene (BCB), polybenzoxazole (PBO), an inorganic dielectric material (e.g., silicon oxide, silicon nitride, and so on), an ABF, or other suitable electrical insulating materials. Nonetheless, the disclosure is not limited thereto. 
     In some embodiments not shown, the first conductive connector  112  may be formed by sequentially stacking a first seed layer, a second seed layer (whose materials include titanium/copper (Ti/Cu)), for example), and an electroplating layer (whose material includes copper, for example), but the disclosure is not limited thereto. In other embodiments, the first conductive connector  112  may include other suitable conductive materials such as silver, gold, nickel, or an alloy thereof, such as Cu, Cu/Ni/Au, Cu/Ti, Cu/Ag, or the like. For example, an adhesive layer (whose material includes titanium, for example) may be formed on a conductive pad (whose material includes copper, for example). Next, a metal layer (whose material includes silver, for example) may be formed on the adhesive layer by electroplating, sputtering, or other suitable deposition manners. The thickness of the adhesive layer may be less than the thickness of the metal layer. It should be noted that, although the first conductive connector  112  is shown in the form of a pad in the drawings, the disclosure is not limited thereto. The first conductive connector may also be in the form of a pillar. 
     In this embodiment, the first group of circuit structure  110  includes a bottom surface  110   b  close to the first temporary carrier  10 , and the antenna pattern  111   a  and the first dielectric layer  111   b  may be substantially flush on the bottom surface  110   b . In addition, the first conductive via  111   c  is gradually thickened (e.g., gradually thickened in width or in diameter) in a direction toward the first conductive connector  112 . In other words, the first conductive via  111   c  tapers (e.g., tapers in width or in diameter) in a direction toward the first temporary carrier  10 . Nonetheless, the disclosure is not limited thereto. 
     In some embodiments, a planarization process on the first conductive connector  112  may be omitted, but the disclosure is not limited thereto. 
     With reference to  FIG.  1 B , a second group of circuit structure  120  is formed on a second temporary carrier  20 . The second group of circuit structure  120  includes a plurality of second circuit layers  121  (three second circuit layers schematically shown in  FIG.  1 B ) and a plurality of second conductive connectors  122 . Each second circuit layer  121  may include a conductive pattern  121   a , a second dielectric layer  121   b , and/or a second conductive via  121   c . Here, the conductive pattern  121   a  and the second conductive via  121   c  may be embedded in the second dielectric layer  121   b , but the disclosure is not limited thereto. 
     In this embodiment, the second group of circuit structure  120  includes a bottom surface  120   b  close to the second temporary carrier  20 . The conductive pattern  121   a  and the second dielectric layer  121   b  may be substantially flush on the bottom surface  120   b . In addition, the second conductive via  121   c  is gradually thickened (e.g., gradually thickened in width or in diameter) in a direction toward the second conductive connectors  122 . In other words, the second conductive via  121   c  tapers (e.g., tapers in width or in diameter) in a direction toward the second temporary carrier  20 . Nonetheless, the disclosure is not limited thereto. 
     It should be noted that, density of the conductive patterns  121   a  of the second circuit layers  121  close to the second conductive connectors  122  and density of the conductive patterns  121   a  of the second circuit layers  121  away from the second conductive connectors  122  may have a density distribution designed depending on the actual design requirements, which is not limited by the disclosure. 
     In addition, the materials of the conductive pattern  121   a  and/or the second conductive via  121   c  are similar to those of the antenna pattern  111   a  and/or the first conductive via  111   c , the material of the first conductive connector  112  is similar to that of the second conductive connector  122 , but the material of the second dielectric layer  121   b  is different from that of the first dielectric layer  111   b . For example, the material of the second dielectric layer  121   b  may be an ABF, polypropylene (PP), or the like. 
     With reference to  FIG.  1 C , the structure as shown in  FIG.  1 A  is flipped upside down, and the first group of circuit structure  110  and the second group of circuit structure  120  are joined by a plurality of joints  130 . The joints  130  connect the first conductive connectors  112  and the second conductive connectors  122  to electrically connect the first group of circuit structure  110  to the second group of circuit structure  120  to form a multi-layer redistribution structure RDL. Here, the joints  130  may be solder joints. In addition, an underfill  101  may be optionally disposed between the first group of circuit structure  110  and the second group of circuit structure  120 . The underfill  101  may be filled in the gap between the first conductive connectors  112  and the second conductive connectors  122 , and the gap may be filled up. Accordingly, the underfill  101  may surround the first conductive connectors  112 , the second conductive connectors  122 , and the joints  130  to further improve joining reliability, but the disclosure is not limited thereto. Through the above manufacturing, a millimeter-wave antenna module package structure  100  of this embodiment has been substantially completed. 
     In this embodiment, the millimeter-wave antenna module package structure  100  includes the first group of circuit structure  110  and the second group of circuit structure  120 . The first group of circuit structure  110  includes the at least one first circuit layer  111  (including the antenna pattern  111   a ) and the first conductive connectors  112 . The second group of circuit structure  120  includes the second circuit layers  121  and the conductive connectors  122 . The joints  130  are disposed between the first group of circuit structure  110  and the second group of circuit structure  120 . The joints  130  connect the conductive connectors  112  and the second conductive connectors  122  to electrically connect the first group of circuit structure  110  to the second group of circuit structure  120  to form the multi-layer redistribution structure RDL. Accordingly, in this embodiment, a plurality of circuit structures (the first group of circuit structure  110  and the second group of circuit structure  120 ) are first separately and individually manufactured on the temporary carriers (the first temporary carrier  10  and the second temporary carrier  20 ), and then the groups of circuit structures are directly joined and assembled into a multi-layer redistribution structure (the multi-layer redistribution structure RDL). As such, compared to continuously manufacturing a multi-layer redistribution structure at one single time, warpage may be effectively reduced, and the distance between the antenna and the IC may be controlled more precisely. Accordingly, in the millimeter-wave antenna module package structure  100  of the embodiment, a relatively high efficiency of a high-frequency antenna may be achieved while the multi-layer redistribution structure RDL is provided. 
     Further, due to limitation of the process, the difficulty may be positively correlated with the number of layers manufactured. Accordingly, as the number of layers to be manufactured increases, the likelihood of damaging the redistribution structure as a whole during the process increases, making it unlikely to effectively control the yields and costs. In this embodiment, since the multi-layer redistribution structure RDL is divided into a plurality of groups of circuit structures with relatively few layers to be manufactured separately and individually, it is possible to avoid the unlikely effective control of the yields and costs in continuous stacking of multiple layers, but the disclosure is not limited thereto. 
     In some embodiments, as the line-spacing (L/S) (e.g., the line width) of the circuits is increasing fine, requirements of the process may be increasing stringent, and it may accordingly be increasingly unlikely when a multi-layer redistribution structure is to be formed. In this embodiment, by joining and assembling groups of circuit structures to manufacture fine line-spacing structures, higher yields and electrical performance may be achieved compared to continuously formed structures. For example, the first group of circuit structure  110  may have fine line-spacing less than at least 7 micrometers (µm), and the second group of circuit structure  120  may have thick line-spacing greater than at least 7 µm. In other words, in this embodiment, the multi-layer redistribution structure RDL may be a combination of a thick line-spacing circuit structure and a fine line-spacing circuit structure, but the disclosure is not limited thereto. 
     In some embodiments, the first conductive via  111   c  is gradually thickened (e.g., gradually thickened in width or in diameter) in a direction toward the first conductive connector  112 , and the second conductive via  121   c  is gradually thickened (e.g., gradually thickened in width or in diameter) in a direction toward the second conductive connector  122 . In other words, the first conductive via  111   c  tapers (e.g., tapers in width or in diameter) in a direction toward the first temporary carrier  10 , and the second conductive via  121   c  tapers (e.g., tapers in width or in diameter) in a direction toward the second temporary carrier  20 . In other words, after the joining process, a direction in which the first conductive via  111   c  tapers is opposite to a direction in which the second conductive via  121   c  tapers. 
     It should be noted that, depending on the actual application requirements, the first temporary carrier  10  and/or the second temporary carrier  20  may optionally be removed to expose the antenna pattern  111   a  and/or the second conductive via  121   c  for electrical connection with other elements. Here, the release layers may be peeled off by applying external energy between the bottom surfaces of the circuit structures and the temporary carriers. 
     In addition, the specific numbers of layers and groups of the first group of circuit structure  110  and the second group of circuit structure  120  may also be adjusted depending on the actual design requirements, which is not limited by the disclosure. For example, the number of the first circuit layers  111  of the first group of circuit structure  110  and the number of the second circuit layers  121  of the second group of circuit structure  120  may be the same or different. For example,  FIG.  1 C  shows an embodiment where the number of the first circuit layer  111  (one first circuit layer) of the first group of circuit structure  110  is different from that of the second circuit layers  121  (three second circuit layers) of the second group of circuit structure  120 . Moreover, the multi-layer redistribution structure RDL may also include more groups of other circuit structures similar to the first group of circuit structure  110  and/or the second group of circuit structure  120 . 
     It should be noted here that the reference numerals and part of the content of the embodiments above remain to be used in the embodiments below, where the same or like reference numerals are used to refer to the same or like elements, and description of the same technical content is omitted. Reference may be made to the embodiments above for the description of the omitted part, which will not be repeated in the embodiments below. 
       FIG.  1 D  is a schematic partial cross-sectional view showing an alternative embodiment of  FIG.  1 C . With reference to  FIG.  1 D , a millimeter-wave antenna module package structure  100 A of  FIG.  1 D  is different from the millimeter-wave antenna module package structure  100  of  FIG.  1 C  in the following: joints  130 A of the millimeter-wave antenna module package structure  100 A are in a form different from the joints  130  of the millimeter-wave antenna module package structure  100 , and part of the gap between the joints  130 A, the first group of circuit structure  110 , and the second group of circuit structure  120  of a multi-layer redistribution structure RDL 1  is not filled with the underfill  101 , such that a cavity C surrounded by the underfill  101  is formed between the first group of circuit structure  110  and the second group of circuit structure  120 . Further, the joints  130 A may have a composite structure, for example, taking a copper ball  131  (which may also be a copper pillar in an alternative embodiment) as the core with a solder layer  132  formed outside the copper ball  131  to cover the copper ball  131 . In addition, the joints  130 A may be located in the cavity C and separated from the underfill  101 . In other words, the joints  130 A may not be in contact with the underfill  101 . 
     In some embodiments, a height H of the gap between the first group of circuit structure  110  and the second group of circuit structure  120  may affect the size of device, the process technology, the antenna performance, and the device applicability, among others. The joints  130 A having a composite structure may be configured to control the height H of the gap between the first group of circuit structure  110  and the second group of circuit structure  120 . Accordingly, the electrical performance of the millimeter-wave antenna module package structure  100 A may be further improved. Nonetheless, the disclosure is not limited thereto. 
     In some embodiments, the cavity C may be an air cavity, and may be additionally filled with other dielectric materials based on applications of the antenna, which is not limited by the disclosure. 
       FIG.  2 A  to  FIG.  2 C  are schematic partial cross-sectional views showing a manufacturing method of a millimeter-wave antenna module package structure according to some embodiments of the disclosure. With reference to  FIG.  2 A , following  FIG.  1 C , a second release layer  22  and the second temporary carrier  20  are removed to expose the second conductive via  121   c  and the second dielectric layer  121   b  on the bottom surface  120   b  of the second group of circuit structure  120 . Next, a plurality of pads  240  are formed on the second conductive via  121   c  on the bottom surface  120   b  of the second group of circuit structure  120 . Here, the pad  240  may be formed using any suitable conductive material in any manner. 
     With reference to  FIG.  2 B , a plurality of first semiconductor devices  250  are disposed on the pads  240  of the second group of circuit structure  120 , and the first semiconductor devices  250  are electrically connected to the second group of circuit structure  120 . In addition, the first semiconductor devices  250  may be electrically connected to the antenna pattern  111   a  of the first group of circuit structure  110  by the second group of circuit structure  120 . 
     In some embodiments, the pads  240  may be distributed with a central region  240   c  and peripheral regions  240   e  located on both sides of the central region. The first semiconductor devices  250  disposed in the central region  240   c  may be RF chips (one schematically shown) and the first semiconductor devices  250  disposed in the peripheral regions  240   e  may be passive elements (two schematically shown). In other words, the passive elements may be located on both sides of the RF chip. Nonetheless, the disclosure is not limited thereto. The number, type, and arrangement position of the first semiconductor devices  250  may be adjusted depending on the actual design requirements. 
     With reference to  FIG.  2 C , an encapsulant  260  is formed on the bottom surface  120   b  of the second group of circuit structure  120  to encapsulate the first semiconductor devices  250 . The encapsulant  260  may be a molding compound formed by a molding process. Here, the encapsulant  260  may be formed of an insulating material such as epoxy resin or other suitable resin, but the disclosure is not limited thereto. Next, a cladding layer  270  may be formed on the encapsulant  260 , such that a millimeter-wave antenna module package structure  200  may have relatively good electromagnetic interference (EMI) shielding. The cladding layer  270   may be conformally formed on the outer surface  260   s  of the encapsulant  260 . Then, the first release layer  12  and the first temporary carrier  10  are removed to complete the millimeter-wave antenna module package structure  200  of this embodiment. Here, the manufacturing process of the cladding layer  270  may include performing a physical vapor deposition or electroplating process, and the material may include copper, tin, aluminum, steel, or other suitable materials. 
     In some embodiments, the millimeter-wave antenna module package structure  200  of  FIG.  2 C  is Antenna-in-Package (AiP), but the disclosure is not limited thereto. 
       FIG.  3 A  to  FIG.  3 E  are schematic partial cross-sectional views showing a manufacturing method of a millimeter-wave antenna module package structure according to some embodiments of the disclosure.  FIG.  3 F  and  FIG.  3 G  are schematic partial cross-sectional views showing alternative embodiments of  FIG.  3 B . With reference to  FIG.  3 A , the first group of circuit structure  110  that is similar to  FIG.  1 A  is provided, while a plurality of second semiconductor devices  380  are further disposed thereon. Here, the second semiconductor devices  380  include an inductor, a capacitor, or the like, for example. Moreover, the number and arrangement positions as shown in  FIG.  3 A  are only exemplary, and the number, type, and arrangement position of the second semiconductor devices  380  may be selected depending on the actual design requirements. 
     With reference to  FIG.  3 B , the second group of circuit structure  120  of  FIG.  1 B  is provided, and the first group of circuit structure  110  and the second group of circuit structure  120  are joined by the joints  130 A as shown in  FIG.  1 D  (the joints  130  as shown in  FIG.  1 C  may also be used in an alternative embodiment), such that there is a sufficient height between the first group of circuit structure  110  and the second group of circuit structure  120  to form a gap, so as to accommodate the second semiconductor devices  380  on the first group of circuit structure  110 . In other words, the second semiconductor devices  380  may be disposed between the first group of circuit structure  110  and the second group of circuit structure  120 . Here, the semiconductor devices  380  may be joined on the first group of circuit structure  110  in a suitable manner, which is not limited by the disclosure. In addition, the first group of circuit structure  110 , the joints  130 A, the second group of circuit structure  120 , the underfill  101 , and the second semiconductor devices  380  may form a multi-layer redistribution structure RDL 2 . 
     In addition, in this embodiment, the underfill  101  may be filled in the gap between the first conductive connectors  112  and the second conductive connectors  122 , and the gap may be filled up. Accordingly, the underfill  101  may surround the first conductive connectors  112 , the second conductive connectors  122 , the joints  130 A, and the second semiconductor devices  380  to further improve joining reliability, but the disclosure is not limited thereto. 
     Comparatively, in some alternative embodiments, the joints  130 A may also have other different aspects. For example, as shown in  FIG.  3 F , the first group of circuit structure  110  and the second group of circuit structure  120  are joined by joints  140 . The joints  140  may include a copper pillar  141  and a solder bump  142 . Further, in the embodiment of  FIG.  3 F , the copper pillar  141  may be in direct contact with the second group of circuit structure  120 , and the solder bump  142  may be in direct contact with the first group of circuit structure  110 , but the disclosure is not limited thereto. In another alternative embodiment, as shown in  FIG.  3 G , the copper pillar  141  may be in direct contact with the first group of circuit structure  110 , and the solder bump  142  may be in direct contact with the second group of circuit structure  120 . 
     With reference to  FIG.  3 C , similar to  FIG.  2 A , the second release layer  22  and the second temporary carrier  20  are removed to expose the second conductive via  121   c  and the second dielectric layer  121   b  on the bottom surface  120   b  of the second group of circuit structure  120 . Next, the pads  240  are formed on the second conductive via  121   c  on the bottom surface  120   b  of the second group of circuit structure  120 . 
     With reference to  FIG.  3 D , similar to  FIG.  2 B , the first semiconductor devices  250  are disposed on the pads  240  of the second group of circuit structure  120 , and the first semiconductor devices  250  are electrically connected to the second group of circuit structure  120 . The first semiconductor devices  250  may be electrically connected to the antenna pattern  111   a  of the first group of circuit structure  110  by the second group of circuit structure  120 . 
     With reference to  FIG.  3 E , similar to  FIG.  2 C , the encapsulant  260  is formed on the bottom surface  120   b  of the second group of circuit structure  120  to encapsulate the first semiconductor devices  250 , and the cladding layer  270  is formed on the encapsulant  260 , such that the millimeter-wave antenna module package structure  200  may have relatively good EMI shielding. Then, the first release layer  12  and the first temporary carrier  10  are removed to complete a millimeter-wave antenna module package structure  300  of this embodiment. 
     In some embodiments, the millimeter-wave antenna module package structure  300  of  FIG.  3 E  is Antenna-in-Package (AiP), but the disclosure is not limited thereto. 
       FIG.  4 A  is a schematic partial cross-sectional view showing an alternative embodiment of  FIG.  1 B .  FIG.  4 B  is a schematic partial cross-sectional view of a millimeter-wave antenna module package structure formed by the circuit structure of  FIG.  4 A .  FIG.  4 C  is a schematic partial cross-sectional view showing an alternative embodiment of  FIG.  1 B . With reference to  FIG.  4 A , the second group of circuit structure  120  that is similar to  FIG.  1 B  is provided, while another first semiconductor device  250   a  is further disposed thereon. Here, the first semiconductor device  250   a  may be an RF chip. In addition, in an alternative embodiment, as shown in  FIG.  4 C , the joints  140  may further be provided, which includes the copper pillar  141  and the solder bump  142 , and are disposed on the second group of circuit structure  120  and located on both sides of the first semiconductor device  250   a . Nonetheless, the disclosure is not limited thereto. 
     Next, with reference to  FIG.  4 B , the first group of circuit structure  110  similar to  FIG.  3 A  is provided (while one second semiconductor device  380  is disposed). The first group of circuit structure  110  and the second group of circuit structure  120  are joined by the joints  130 A as shown in  FIG.  1 D  (the joints  130  as shown in  FIG.  1 C  may also be used in an alternative embodiment). The first group of circuit structure  110 , the joints  130 A, the second group of circuit structure  120 , the underfill  101 , the first semiconductor device  250   a , and the second semiconductor device  380  may form a multi-layer redistribution structure RDL 3 . Then, a millimeter-wave antenna module package structure  400  of this embodiment is completed by steps similar to  FIG.  3 C  to  FIG.  3 E . Further, in this embodiment, a part of the first semiconductor devices (i.e., the first semiconductor device  250 ) is disposed on a surface S 1  of the second group of circuit structure, and another part of the first semiconductor devices (i.e., first semiconductor device  250   a ) is disposed on another surface S 2  of the second group of circuit structure  120  opposite to the surface S 1 . Moreover, since the first semiconductor device  250   a  may be an RF chip, the first semiconductor device  250  disposed in the central region  240   c  on the surface S 1  of the second group of circuit structure may be other IC chips. In addition, since the first semiconductor device  250   a  (e.g., an RF chip) is disposed in the gap between the first group of circuit structure  110  and the second group of circuit structure  120 , the first device  250   a  (e.g., an RF chip) may be embedded in the underfill  101 , but the disclosure is not limited thereto. 
     It should be noted that the multi-layer redistribution structure in the millimeter-wave antenna module package structure may also be replaced with the multi-layer redistribution structure RDL 1  (having the cavity C) in  FIG.  1 D . In addition, the first group of circuit structure  110  may also be replaced with a circuit structure having thick line-spacing greater than at least 7 µm and having an antenna pattern, and the second group of circuit structure  120  may also be replaced with a circuit structure having fine line-spacing less than at least 7 µm. 
     In summary of the foregoing, in an embodiment of the disclosure, a plurality of groups of circuit structures are first separately and individually manufactured on the temporary carriers, and then the groups of circuit structures are directly joined and assembled into a multi-layer redistribution structure. As such, compared to continuously manufacturing a multi-layer redistribution structure at one single time, warpage may be effectively reduced, and the distance between the antenna and the IC may be controlled more precisely. Accordingly, in the millimeter-wave antenna module package structure in an embodiment of the disclosure, a relatively high efficiency of a high-frequency antenna may be achieved while the multi-layer redistribution structure is provided. 
     It will be apparent to those skilled in the art that various modifications and variations can be made to the disclosed embodiments without departing from the scope or spirit of the disclosure. In view of the foregoing, it is intended that the disclosure covers modifications and variations provided that they fall within the scope of the following claims and their equivalents.