Patent Publication Number: US-2023132846-A1

Title: Electronic device and manufacturing method thereof

Description:
BACKGROUND 
     Technical Field 
     The present disclosure relates to an electronic device, and more particularly, to an electronic device with an antenna module and a manufacturing method thereof. 
     Description of Related Art 
     The current multimedia content has a larger amount of file data due to the improvement of image quality, so the bandwidth of wireless transmission also needs to be larger, thereby resulting in the fifth generation of wireless transmission (5G). In addition, due to the high transmission frequency of 5G, the size requirements of the related wireless communication modules are also high. 
     In the conventional antenna module, when the antenna structure is planar, the electromagnetic radiation characteristics between the antenna structure and the electronic elements will be limited, so that it is difficult to improve the antenna performance. Therefore, how to overcome the above-mentioned drawbacks of the prior art has become an urgent issue to be overcome in the current industry. 
     SUMMARY 
     In view of the various deficiencies of the prior art, the present disclosure provides an electronic device, comprising: a circuit board; a carrier structure having a first side and a second side opposing the first side, wherein the carrier structure is stacked on the circuit board via a plurality of conductive elements with the second side thereof an antenna layer formed on the first side of the carrier structure; a micro strip disposed on the second side of the carrier structure, wherein a position of the antenna layer corresponds to a position of the micro strip; an encapsulation layer formed on the first side of the carrier structure; an antenna portion disposed on the encapsulation layer and communicatively connected to the antenna layer; an antenna spacer disposed on the first side of the carrier structure by corresponding to the position of the antenna layer and located between the antenna layer and the antenna portion, wherein the antenna spacer is covered by the encapsulation layer; and a reflector disposed on a side of the circuit board facing the carrier structure and communicatively connected to the antenna layer. 
     The present disclosure further provides a method of manufacturing an electronic device, comprising: providing a carrier structure having a first side and a second side opposing the first side, wherein the first side of the carrier structure has an antenna layer formed thereon, and a micro strip is disposed on the second side of the carrier structure, and wherein a position of the antenna layer corresponds to a position of the micro strip; disposing an antenna spacer on the first side of the carrier structure; forming an encapsulation layer on the first side of the carrier structure for the encapsulation layer to cover the antenna spacer; bonding an antenna portion communicatively connected to the antenna layer on the encapsulation layer on the first side of the carrier structure; and disposing the carrier structure onto a circuit board having a reflector with the second side of the carrier structure via a plurality of conductive elements, wherein the reflector is disposed on a side of the circuit board facing the carrier structure and communicatively connected to the antenna layer. 
     In the aforementioned electronic device and method, the present disclosure further comprises forming a plurality of electrical contact pads on the second side of the carrier structure, wherein the plurality of conductive elements are only disposed on a portion of the plurality of electrical contact pads. 
     In the aforementioned electronic device and method, the antenna layer is a coplanar waveguide, wherein a width of the reflector is greater than a width of the coplanar waveguide, and wherein the antenna layer is communicatively connected to the reflector via the plurality of conductive elements and a portion of a plurality of electrical contact pads. 
     In the aforementioned electronic device and method, the antenna portion comprises an antenna body communicatively connected to the antenna layer, wherein a position of the antenna body corresponds to a position of the antenna spacer, and wherein a position of the reflector corresponds to the position of the antenna layer. 
     In the aforementioned electronic device and method, the present disclosure further comprises disposing an electronic element on the first side of the carrier structure, wherein the encapsulation layer covers the electronic element when the encapsulation layer is formed on the first side of the carrier structure. 
     As can be seen from the above, in the electronic device and the manufacturing method thereof of the present disclosure, a better antenna performance can be obtained by disposing the micro strip on the second side of the carrier structure and disposing the conductive elements only on a portion of the electrical contact pads. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a schematic cross-sectional view of an electronic device according to the present disclosure. 
         FIG.  2    is a schematic bottom view of an antenna module of the electronic device according to the present disclosure. 
         FIG.  3 A  to  FIG.  3 G  are schematic cross-sectional views illustrating a method of manufacturing the electronic device according to the present disclosure. 
     
    
    
     DETAILED DESCRIPTIONS 
     The following describes the implementation of the present disclosure with examples. Those skilled in the art can easily understand other advantages and effects of the present disclosure from the contents disclosed in this specification. 
     It should be understood that, the structures, ratios, sizes, and the like in the accompanying figures are used for illustrative purposes to facilitate the perusal and comprehension of the contents disclosed in the present specification by one skilled in the art, rather than to limit the conditions for practicing the present disclosure. Any modification of the structures, alteration of the ratio relationships, or adjustment of the sizes without affecting the possible effects and achievable proposes should still be deemed as falling within the scope defined by the technical contents disclosed in the present specification. Meanwhile, terms such as “upper,” “on,” “first,” “second,” “a,” “one” and the like used herein are merely used for clear explanation rather than limiting the practicable scope of the present disclosure, and thus, alterations or adjustments of the relative relationships thereof without essentially altering the technical contents should still be considered in the practicable scope of the present disclosure. 
       FIG.  1    is a schematic cross-sectional view of an electronic device  2  according to the present disclosure. As shown in  FIG.  1   , the electronic device  2  at least includes: an antenna module  2   a,  and a circuit board  2   b  provided with a reflector  25 , wherein the antenna module  2   a  includes a carrier structure  20 , an electronic element  21 , an antenna spacer  22 , an encapsulation layer  23  and an antenna portion  24 . 
     The carrier structure  20  has a first side  20   a  and a second side  20   b  opposing the first side  20   a,  wherein at least one antenna layer  202  is configured on the first side  20   a  to serve as a coplanar waveguide (CPW), and a micro strip  203  is configured on the second side  20   b,  so that the position of the antenna layer  202  corresponds to the position of the micro strip  203 , such that the antenna layer  202  covers the micro strip  203 , and wherein a plurality of conductive elements  26  are disposed on the second side  20   b,  so that the antenna module  2   a  is stacked on the circuit board  2   b  via the conductive elements  26 . The conductive elements  26  can be ball grid array connectors, solder balls, metal pillars, micro bumps, or other similar elements, and the material for forming the conductive elements  26  may be composed of solder, copper, aluminum, gold, nickel, silver, palladium, tin, and combinations of the foregoing. 
     The electronic element  21  is disposed on the first side  20   a  of the carrier structure  20  and is electrically connected to the carrier structure  20 . 
     The antenna spacer  22  is also disposed on the first side  20   a  of the carrier structure  20 , and the antenna spacer  22  is disposed separately from the electronic element  21 . 
     The encapsulation layer  23  is disposed on the first side  20   a  of the carrier structure  20  and covers the electronic element  21  and the antenna spacer  22 . 
     The antenna portion  24  has an antenna body  24   a  covered by an insulating material, is disposed on the encapsulation layer  23 , and communicatively connects with the carrier structure  20 . 
     The reflector  25  is disposed on a surface of the circuit board  2   b  facing the second side  20   b  of the carrier structure  20  (that is, the reflector  25  is disposed between the second side  20   b  of the carrier structure  20  and the circuit board  2   b ), and communicatively connects with the carrier structure  20 . 
     In one embodiment, in the electronic device  2  of the present disclosure, a plurality of electrical contact pads  260  can be formed on the second side  20   b  of the carrier structure  20  to bond the conductive elements  26 , and the conductive elements  26  are only arranged on a portion of the electrical contact pads  260 , such as arranged in a row as shown in  FIG.  2    (but not limited thereto), thereby improving the gain of the electronic device  2  of the present disclosure. 
     Therefore, in the electronic device  2  of the present disclosure, the position of the micro strip  203  is set in the second side  20   b  of the carrier structure  20 , so as to increase the length of the micro strip  203 . Compared with the prior art of disposing the micro strip on the top surface of the circuit board, the electronic device  2  of the present disclosure can greatly improve the performance, for example, the bandwidth is improved by about 7.4 GHz, the center frequency is improved by about 60 GHz and/or the gain is improved by about 6.7 dB. 
     Furthermore, the antenna layer  202  (CPW) of the electronic device  2  of the present disclosure is connected to the reflector  25  via the conductive elements  26  and a portion of the electrical contact pads  260 , so that the CPW is grounded. Compared with the prior art of connecting all solder balls to the circuit board, the electronic device  2  of the present disclosure can greatly improve the performance, for example, the antenna gain of the present disclosure can be improved (about 5 dB). 
       FIG.  3 A  to  FIG.  3 G  are schematic cross-sectional views illustrating a method of manufacturing the electronic device  2  according to the present disclosure. 
     As shown in  FIG.  3 A , a carrier structure  20  disposed on a support member  9  is provided, and the carrier structure  20  has a first side  20   a  and a second side  20   b  opposing the first side  20   a,  wherein the first side  20   a  is defined with a first area A and a second area B adjacent to the first area A, and the carrier structure  20  is bonded onto the support member  9  with the second side  20   b  thereof. 
     In an embodiment, the carrier structure  20  is composed of an insulating layer (dielectric layer)  200  and a circuit layer  201  such as a fan-out redistribution layer (RDL), wherein the material for forming the circuit layer  201  may be copper or gold, etc., and the material for forming the insulating layer  200  may be a dielectric material such as polybenzoxazole (PBO), polyimide (PI), prepreg (PP), etc. 
     Furthermore, the carrier structure  20  is configured with at least one antenna layer  202  in the uppermost insulating layer  200  (i.e., the top layer) for serving as a coplanar waveguide (CPW), and the circuit layer  201  in the lowermost insulating layer  200  (e.g., the PI layer) (i.e., the bottom layer) of the carrier structure  20  has a micro strip  203 , so that the position of the antenna layer  202  corresponds to the position of the micro strip  203 , such that the antenna layer  202  covers the micro strip  203 . 
     In addition, the support member  9  can be, for example, a plate made of semiconductor material (such as silicon or glass), and the carrier structure  20  can be fixed on the support member  9  via an adhesive material such as an adhesive layer  90 . 
     As shown in  FIG.  3 B , at least one electronic element  21  is disposed on the first area A of the first side  20   a  of the carrier structure  20 , and at least one antenna spacer  22  is disposed on the second area B of the first side  20   a  of the carrier structure  20 , wherein the antenna spacer  22  is disposed separately from the electronic element  21 . 
     In an embodiment, the electronic element  21  is an active element, a passive element, or a combination of the active element and the passive element, wherein the active element is such as a semiconductor chip, and the passive element is such as a resistor, a capacitor, or an inductor. In an embodiment, the electronic element  21  is a semiconductor chip, such as a radio-frequency chip (radio-frequency integrated circuits [RFIDs]), which has an active surface  21   a  and an inactive surface  21   b  opposing the active surface  21   a,  wherein the electronic element  21  is disposed on the circuit layer  201  in a flip-chip manner via a plurality of conductive bumps  210  such as solder material and is electrically connected to the circuit layer  201 ; alternatively, the electronic element  21  can be electrically connected to the circuit layer  201  in a wire-bonding manner via a plurality of bonding wires (not shown); or, the electronic element  21  can directly contact the circuit layer  201 . However, the manner in which the electronic element  21  is electrically connected to the carrier structure  20  is not limited to the above. 
     Furthermore, the antenna spacer  22  is a block made of glass or silicon material. In an embodiment, the antenna spacer  22  is of a chip specification such as a carrier chip. For example, the antenna spacer  22  can be attached onto the carrier structure  20  via a bonding layer  220  such as adhesive to cover the antenna layer  202 . 
     As shown in  FIG.  3 C , an encapsulation layer  23  is formed on the first side  20   a  of the carrier structure  20 , so that the encapsulation layer  23  covers the electronic element  21  and the antenna spacer  22 . In an embodiment, the encapsulation layer  23  is made from an insulating dielectric material, such as Ajinomoto build-up film (ABF), photosensitive resin, polyimide (PI), bismaleimide triazine (BT), flame resistant/retardant 5 prepreg (FR5 PP), dry film, epoxy resin, molding compound, epoxy molding compound (EMC), or other suitable materials, which can be formed on the first side  20   a  of the carrier structure  20  by means of lamination or molding. 
     As shown in  FIG.  3 D , an antenna portion  24  is formed on the encapsulation layer  23 , and the antenna portion  24  includes a dielectric layer  240  formed on the encapsulation layer  23  and an antenna body  24   a  formed on the dielectric layer  240 . In an embodiment, the antenna body  24   a  is a patch antenna, which is adhered on the dielectric layer  240 . In other embodiments, a metal layer may also be formed by electroplating, electroless plating, physical vapor deposition, sputtering, or other suitable methods to serve as the antenna body  24   a.    
     Furthermore, the antenna body  24   a  and the antenna layer  202  are communicatively connected to each other (e.g., signal inductive coupling). For example, the position of the antenna body  24   a  corresponds to the position of the antenna spacer  22 , that is, the two are opposite to each other up and down. 
     In addition, the encapsulation layer  23  and the dielectric layer  240  can be made of the same or different materials, which are not particularly limited. 
     In addition, the antenna portion  24  can be provided with an insulating protective layer  242  covering the antenna body  24   a  according to requirements, wherein the insulating protective layer  242  is made from a dielectric material and is formed on the dielectric layer  240 . Therefore, the insulating protective layer  242  and the dielectric layer  240  can be seen as a whole, and serve as a covering body  24   b  to cover the antenna body  24   a.  It should be understood that the dielectric layer  240  can also be omitted, and the antenna body  24   a  is directly disposed on the encapsulation layer  23 . 
     As shown in  FIG.  3 E , the support member  9  and the adhesive layer  90  thereon are removed to expose the second side  20   b  of the carrier structure  20 . In an embodiment, the adhesive layer  90  can be a release film, so as to facilitate the removal of the support member  9 . 
     As shown in  FIG.  3 F , a plurality of conductive elements  26  such as solder balls are disposed on the second side  20   b  of the carrier structure  20  and are electrically connected to the circuit layer  201  of the carrier structure  20 . 
     In an embodiment, a plurality of electrical contact pads  260  that are electrically connected to the circuit layer  201  can be formed on the second side  20   b  of the carrier structure  20  to bond to the conductive elements  26 . The configuration of the electrical contact pads  260  is favorable for disposing the conductive elements  26 . 
     Furthermore, the conductive elements  26  are only arranged on a portion of the electrical contact pads  260 , such as a row as shown in  FIG.  2   . 
     As shown in  FIG.  3 G , the carrier structure  20  is disposed on a circuit board  2   b  having at least one reflector  25  via the conductive elements  26 , so that the circuit layer  201  of the carrier structure  20  is electrically connected to the circuit board  2   b  via the plurality of conductive elements  26 , and the reflector  25  is communicatively connected to the antenna layer  202 , so that the micro strip  203 , the antenna layer  202 , the antenna spacer  22 , the antenna portion  24  and the reflector  25  serve as an antenna structure, wherein the antenna layer  202  serves as a coplanar waveguide (CPW) of the antenna structure, and is electrically connected to the reflector  25  of the circuit board  2   b  via the circuit layer  201  and the conductive elements  26  to ground the coplanar waveguide (CPW). 
     In an embodiment, the reflector  25  can be formed on the circuit board  2   b  by an RDL routing/wiring process, so that the reflector  25  is free from contacting the second side  20   b  of the carrier structure  20 . Therefore, the distance H between the CPW and the reflector  25  will be increased by arranging the antenna layer  202  (coplanar waveguide) on the first side  20   a  of the carrier structure  20 , so that the electronic device  2  can obtain better resonance effect and better antenna performance. 
     Furthermore, by disposing the reflector  25  on the circuit board  2   b,  the reflector  25  can effectively reflect the signal from the antenna body  24   a  of the antenna portion  24  through the antenna layer  202  of the carrier structure  20 , so as to improve the signal directivity of the antenna body  24   a,  so that the radiation direction of the antenna body  24   a  can be in an ideal direction. 
     In addition, the reflector  25  and the antenna layer  202  are inductively coupled to each other. For example, the position of the reflector  25  corresponds to the position of the antenna layer  202 , that is, the two are aligned up and down with respect to the second side  20   b.    
     In addition, a width P 1  of the reflector  25  is greater than a width P 2  of the coplanar waveguide, thereby avoiding the problems of signal scattering and gain reduction. 
     Therefore, in the manufacturing method of the electronic device  2  of the present disclosure, the carrier structure  20 , the antenna spacer  22 , the antenna portion  24  and the reflector  25  are stacked up and down to form a three-dimensional antenna structure, so that during the manufacturing process, the carrier structure  20 , the antenna spacer  22  and the antenna portion  24  can be integrally fabricated with the electronic element  21 , that is, packaged together, so that the encapsulation layer  23  can cover the electronic element  21  and the antenna spacer  22 . Therefore, the mold used in the packaging process can correspond to the size of the carrier structure  20 , which is beneficial to the packaging process. 
     Furthermore, in the manufacturing method of the present disclosure, the antenna portion  24  and the electronic element  21  are disposed in the same antenna module  2   a,  so that the reflector  25  of the antenna structure only needs to communicatively connect with the radio-frequency chip (the electronic element  21 ) of any frequency of the antenna module  2   a,  and the antenna portion  24  of the electronic device  2  can emit 5G millimeter waves of the required frequency. Therefore, when mass-producing the electronic device  2 , the manufacturing method of the present disclosure can produce radio-frequency products of various frequencies, thereby reducing the number of production lines to reduce production costs, and increasing production speed to increase productivity. 
     Furthermore, in the manufacturing method of the present disclosure, the antenna structure is fabricated by using a circuit substrate manufacturing process, so that the antenna structure can be fabricated by a packaging process during the manufacturing process, thereby facilitating packaging operations. 
     In addition, the 5G system requires more circuit configurations due to signal quality and transmission speed requirements to improve signal quality and transmission speed. The manufacturing method of the present disclosure utilizes the circuit substrate manufacturing process to manufacture the micro strip  203  and the antenna layer  202  of the carrier structure  20 , so that the circuit routing/wiring space (number of layers) can be increased under the condition that the length and width of the carrier structure  20  are fixed, so as to increase the function of the antenna structure. Therefore, the electronic device  2  can provide the electrical functions required to operate the 5G system, that is, the electronic device  2  can meet the requirements of the antenna operation of the 5G system. 
     In addition, in the electronic device and the manufacturing method thereof of the present disclosure, a better antenna performance can be obtained by disposing the micro strip on the bottom layer of the carrier structure and disposing the coplanar waveguide on the top layer of the carrier structure, wherein the conductive elements are only provided on a portion of the electrical contact pads. 
     The foregoing embodiments are provided for the purpose of illustrating the principles and effects of the present disclosure, rather than limiting the present disclosure. Anyone skilled in the art can modify and alter the above embodiments without departing from the spirit and scope of the present disclosure. Therefore, the scope of protection with regard to the present disclosure should be as defined in the accompanying claims listed below.