Patent Publication Number: US-2021166839-A1

Title: Transmission line using nanostructured material and method of manufacturing the transmission line

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority to and the benefit of Korean Patent Application No. 2018-0103892, filed on Aug. 31, 2018, the disclosure of which is incorporated herein by reference in its entirety. 
     FIELD 
     The present invention relates to a transmission line, and more particularly, to a transmission line using a nanostructured material formed by electrospinning a liquid resin at a high voltage and a method of manufacturing the transmission line. 
     BACKGROUND 
     In order to transmit or treat a superhigh frequency signal at a small loss, a low-loss and high performance transmission line is necessary. Generally, losses at a transmission line are roughly divided into a conductor loss caused by a metal and a dielectric loss caused by a dielectric. Particularly, a loss caused by a dielectric increases when permittivity of a dielectric is higher, and a power loss increases when resistance is greater. 
     Accordingly, in order to manufacture a low-loss and high performance transmission line for transmitting a superhigh frequency signal, it is necessary to use a material having low permittivity and a small loss tangent value. Particularly, in order to efficiently transmit signals having frequencies in bands of 3.5 GHz and 28 GHz used in 5G mobile communication network, the significance of a transmission line which has a low loss even in a superhigh frequency band increases more and more. 
     SUMMARY 
     The present invention is directed to providing a transmission line using a nanostructured material, which has low permittivity and is capable of reducing a loss tangent value at the low permittivity to reduce a loss at the transmission line caused by a dielectric. 
     The present invention is also directed to providing a method of manufacturing a transmission line using a nanostructured material formed through electrospinning, which has low permittivity and is capable of reducing a loss tangent value at the low permittivity to reduce a loss at a transmission line caused by a dielectric. 
     According to an aspect of the present invention, there is provided a transmission line using a nanostructured material. The transmission line includes a first nanoflon layer formed of nanoflon, a first insulating layer located above the first nanoflon layer, a first pattern formed by etching a first conductive layer formed on the first insulating layer, and a first ground layer located below the first nanoflon layer. Here, the nanoflon is a nanostructured material formed by electrospinning a liquid resin at a high voltage. 
     The first pattern may include ground lines and a signal line which are formed by etching the first conductive layer. The transmission line may further include a second nanoflon layer located on the first pattern formed on the first insulating layer and the first insulating layer exposed by the etching and a second ground layer located on the second nanoflon layer. 
     The transmission line may further include a second nanoflon layer located on the first pattern formed on the first insulating layer and the first insulating layer exposed by the etching, a second ground layer located on the second nanoflon layer, a third nanoflon layer located on the second ground layer, a second insulating layer located on the third nanoflon layer, and a second pattern formed by etching a second conductive layer formed on the second insulating layer and transmits a signal. 
     The second pattern may include ground line and a signal line configured to transmit a signal, which are formed by etching the second conductive layer. 
     The transmission line may further include a fourth nanoflon layer located on the second pattern formed on the second insulating layer and the second insulating layer exposed by the etching and a third ground layer located on the fourth nanoflon layer. The first and second insulating layers may be formed of polyimide (PI), and the conductive layers may be formed of copper (Cu). 
     According to another aspect of the present invention, there is provided a method of manufacturing a transmission line using a nanostructured material. The method includes forming a first conductive layer on a first insulating layer, forming a first pattern, which transmits and receives a signal, by etching the first conductive layer, locating the first insulating layer above a first nanoflon layer formed of nanoflon, and locating a first ground layer below the first nanoflon layer. Here, the nanoflon is a nanostructured material formed by electrospinning a liquid resin at a high voltage. The forming of the first pattern may include forming ground lines and a transmission-signal line by etching the first conductive layer. 
     The method may further include locating a second nanoflon layer on the first pattern formed on the first insulating layer and the first insulating layer exposed by the etching and locating a second ground layer on the second nanoflon layer. 
     The method may further include locating a second nanoflon layer on the first pattern formed on the first insulating layer and the first insulating layer exposed by the etching, locating a second ground layer on the second nanoflon layer, locating a third nanoflon layer on the second ground layer, locating a second insulating layer on the third nanoflon layer, forming a second conductive layer on the second insulating layer, and forming a second pattern, which transmits and receives a signal, by etching the second conductive layer. 
     The method may further include locating a second nanoflon layer on the first pattern formed on the first insulating layer and the first insulating layer exposed by the etching, locating a second ground layer on the second nanoflon layer, locating a third nanoflon layer on the second ground layer, forming a second conductive layer on a second insulating layer, forming a second pattern, which transmits and receives a signal, by etching the second conductive layer, and locating the second insulating layer on the third nanoflon layer. 
     The forming of the second pattern may include forming a transmission-signal line and ground line by etching the second conductive layer. 
     The method may further include locating a fourth nanoflon layer on the second pattern formed on the second insulating layer and the second insulating layer exposed by the etching and bonding a third ground layer to the fourth nanoflon layer. 
     The locating may be performed through adhesion using an adhesive tape or an adhesive or using thermal adhesion in which heat is applied to an adhesive tape. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other objects, features and advantages of the present invention will become more apparent to those of ordinary skill in the art by describing exemplary embodiments thereof in detail with reference to the accompanying drawings, in which: 
         FIG. 1  illustrates an example of an apparatus which manufactures nanoflon through electrospinning; 
         FIG. 2  illustrates an example of a stripline transmission line; 
         FIG. 3  is a cross-sectional view illustrating a first embodiment of a transmission line using a nanostructured material according to the present invention; 
         FIG. 4  is a cross-sectional view of the transmission line, which illustrates adhesion to a first nanoflon layer according to the present invention; 
         FIG. 5  is a cross-sectional view illustrating a second embodiment of the transmission line using the nanostructured material according to the present invention; 
         FIG. 6  is a cross-sectional view illustrating a third embodiment of the transmission line using the nanostructured material according to the present invention; 
         FIG. 7  is a cross-sectional view of the transmission line, which illustrates adhesion to a second nanoflon layer  610  according to the present invention; 
         FIG. 8  is a cross-sectional view illustrating a fourth embodiment of the transmission line using the nanostructured material according to the present invention; 
         FIG. 9  is a cross-sectional view illustrating a fifth embodiment of the transmission line using the nanostructured material according to the present invention; 
         FIG. 10  is a cross-sectional view illustrating a sixth embodiment of the transmission line using the nanostructured material according to the present invention; 
         FIGS. 11A, 11B and 11C  illustrate a first embodiment of a method of manufacturing a transmission line using a nanostructured material according to the present invention; 
         FIG. 12  illustrates a second embodiment of the method of manufacturing the transmission line using the nanostructured material according to the present invention; 
         FIGS. 13A and 13B  illustrate a third embodiment of the method of manufacturing the transmission line using the nanostructured material according to the present invention; 
         FIGS. 14A and 14B  illustrate a fourth embodiment of the method of manufacturing the transmission line using the nanostructured material according to the present invention; 
         FIGS. 15A, 15B, and 15C  illustrate a fifth embodiment of the method of manufacturing the transmission line using the nanostructured material according to the present invention; 
         FIGS. 16A, 16B, 16C, 16D, and 16E  illustrate a sixth embodiment of the method of manufacturing the transmission line using the nanostructured material according to the present invention; 
         FIGS. 17A and 17B  illustrate a seventh embodiment of the method of manufacturing the transmission line using the nanostructured material according to the present invention; 
         FIGS. 18A, 18B, 18C, and 18D  illustrate an eighth embodiment of the method of manufacturing the transmission line using the nanostructured material according to the present invention; and 
         FIGS. 19A and 19B  illustrate a ninth embodiment of the method of manufacturing the transmission line using the nanostructured material according to the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the attached drawings. Since embodiments disclosed in the specification and components shown in the drawings are merely exemplary embodiments of the present invention and do not represent an entirety of the technical concept of the present invention, it should be understood that a variety of equivalents and modifications capable of substituting the embodiments and the components may be present at the time of filing of the present application. 
     First, a nanostructured material used in a transmission line using a nanostructured material according to the present invention will be described. The nanostructured material refers to a material formed by electrospinning a liquid resin at a high voltage and will be referred to as nanoflon herein.  FIG. 1  illustrates an example of an apparatus which manufactures nanoflon through electrospinning. When a polymer solution including polymers is injected into an injector and a high voltage is applied between the injector and a substrate on which spinning is performed and the polymer solution flows at a certain speed thereinto, as electricity is applied to a liquid suspended from an end of a capillary due to surface tension, a nano-sized thread is formed, and as time passes, non-woven nanofibers which are a nanostructured material are accumulated. A material formed by accumulating nanofibers as described above is nanoflon. As the polymer material used for electrospinning, for example, there are present polyurethane (PU), polyvinylidine diflouride (PVDF), nylon (polyamide), polyacrylonitrile (PAN), and the like. Nanoflon may be used as a dielectric of a transmission line due to low permittivity and a large amount of air therein. 
       FIG. 2  illustrates an example of a stripline transmission line. Referring to  FIG. 2 , the stripline transmission line may include a signal line  210  which transmits a signal, a dielectric  220  which surrounds the signal line  210 , and a conductor  230  which functions as an outer shield. 
       FIG. 3  is a cross-sectional view illustrating a first embodiment of a transmission line using a nanostructured material according to the present invention. Referring to  FIG. 3 , the first embodiment with respect to the transmission line using the nanostructured material according to the present invention includes a first nanoflon layer  310 , a first insulating layer  320 , a first pattern  340 , and a first ground layer  350 . The first nanoflon layer  310  includes nanoflon. The first insulating layer  320  includes an insulating material and is located above the first nanoflon layer  310 , and for example, may be located through adhesion. The insulating material is a material capable of preventing an etching solution from being absorbed, and for example, polyimide (PI), as thermally durable plastic, which is an organic polymer compound may be used. 
     The first pattern  340  may be formed by etching a first conductive layer  330  formed on the first insulating layer  320  and functions as a transmission line through which a signal is transmitted. Also, the first ground layer  350  may be located below the first nanoflon layer  310 , and for example, may be located by adhesion. 
     The adhesion to the first nanoflon layer  310  may be performed using an adhesive tape, an adhesive, or thermal adhesion in which heat is applied to an adhesive tape. Also, the first insulating layer  320  may be a first coating layer formed by coating the first nanoflon layer  310  with an insulating material. 
       FIG. 4  is a cross-sectional view of the transmission line which illustrates adhesion to the first nanoflon layer  310  according to the present invention. Reference numeral  410  indicates adhesion between the first nanoflon layer  310  and the first insulating layer  320 , and reference numeral  420  indicates adhesion between the first nanoflon layer  310  and the first ground layer  350 . 
       FIG. 5  is a cross-sectional view illustrating a second embodiment of the transmission line using the nanostructured material according to the present invention. Referring to  FIG. 5 , in the second embodiment with respect to the transmission line using the nanostructured material according to the present invention, when the first embodiment of the transmission line using the nanostructured material according to the present invention is formed, ground lines  510  and  520  are further formed and the first pattern  530  is used as a signal line. That is, the ground lines  510  and  520  and a signal line  530  are formed by etching the first conductor layer  330 . 
       FIG. 6  is a cross-sectional view illustrating a third embodiment of the transmission line using the nanostructured material according to the present invention. Referring to  FIG. 6 , the third embodiment with respect to the transmission line using the nanostructured material according to the present invention further includes a second nanoflon layer  610  and a second ground layer  620  in addition to the first embodiment (refer to  FIG. 3 ) of the transmission line using the nanostructured material according to the present invention. 
     The second nanoflon layer  610  may be located above the first pattern  340  formed on the first insulating layer  320  and the first insulating layer  320  exposed by the etching, and may be located through adhesion. The second ground layer  620  may be located above the second nanoflon layer  610  and may be located through adhesion. The adhesion to the second nanoflon layer  610  may be performed using an adhesive tape, an adhesive, or thermal adhesion in which heat is applied to an adhesive tape. 
       FIG. 7  is a cross-sectional view of the transmission line which illustrates adhesion to the second nanoflon layer  610  according to the present invention. Reference numeral  710  indicates adhesion between the second nanoflon layer  610  and the first insulating layer  320  and the first pattern  340 , and reference numeral  720  indicates adhesion between the second nanoflon layer  610  and the second ground layer  620 . 
       FIG. 8  is a cross-sectional view illustrating a fourth embodiment of the transmission line using the nanostructured material according to the present invention. Referring to  FIG. 8 , the fourth embodiment with respect to the transmission line using the nanostructured material according to the present invention further includes a third nanoflon layer  810 , a second insulating layer  820 , and a second pattern  840  in addition to the third embodiment (refer to  FIG. 6 ) of the transmission line using the nanostructured material according to the present invention. The third nanoflon layer  810  may be located above the second ground layer  620  and may be located through adhesion. The second insulating layer  820  may be located on the third nanoflon layer  810  and may be located through adhesion. The second pattern  840  may be formed by etching a second conductive layer  830  formed on the second insulating layer  820  and is used as a signal line which transmits a signal. The adhesion to the third nanoflon layer  810  may be performed using an adhesive tape, an adhesive, or thermal adhesion in which heat is applied to an adhesive tape. Also, the second insulating layer  820  may be a second coating layer formed by coating the third nanoflon layer  810  with an insulating material. 
       FIG. 9  is a cross-sectional view illustrating a fifth embodiment of the transmission line using the nanostructured material according to the present invention. Referring to  FIG. 9 , in the fifth embodiment with respect to the transmission line using the nanostructured material according to the present invention, when the fourth embodiment of the transmission line using the nanostructured material according to the present invention is formed, ground lines  910  and  920  are further formed and the second pattern  930  is used as a signal line. That is, the ground lines  910  and  920  and the signal line  930  are formed by etching the second conductor layer  830 . 
       FIG. 10  is a cross-sectional view illustrating a sixth embodiment of the transmission line using the nanostructured material according to the present invention. Referring to  FIG. 10 , the sixth embodiment with respect to the transmission line using the nanostructured material according to the present invention further includes a fourth nanoflon layer  1010  and a third ground layer  1020  in addition to the fourth embodiment (refer to  FIG. 8 ) of the transmission line using the nanostructured material according to the present invention. 
     The fourth nanoflon layer  1010  may be located on the second pattern  840  formed on the second insulating layer  820  and the second insulating layer  820  exposed by the etching, and may be located through adhesion. The third ground layer  1020  may be located on the fourth nanoflon layer  1010  and may be located through adhesion. The adhesion to the fourth nanoflon layer  1010  may be performed using an adhesive tape, an adhesive, or thermal adhesion in which heat is applied to an adhesive tape. 
       FIG. 11  illustrates a first embodiment of a method of manufacturing a transmission line using a nanostructured material according to the present invention. Referring to  FIG. 11( a ) , a first conductive layer  1120  is formed on a first insulating layer  1110 . Referring to  FIG. 11( b ) , a first pattern  1130 , which transmits and receives a signal, is formed by etching the first conductor layer  1120 . In the etching, the first conductive layer  1120  may be etched using a product in which the first conductive layer  1120  is formed on the first insulating layer  1110 . 
     Referring to  FIG. 11( c ) , the first insulating layer  1110  is located above a first nanoflon layer  1140  formed of nanoflon. For example, the first insulating layer  1110  may be located above the first nanoflon layer  1140  by allowing the first insulating layer  1110  to adhere ( 1115 ) to the first nanoflon layer  1140 , and the adhesion may be performed using an adhesive tape, an adhesive, or thermal adhesion in which heat is applied to an adhesive material. A first ground layer  1150  is located below the first nanoflon layer  1140 . For example, the first ground layer  1150  may adhere ( 1155 ) to a bottom of the first nanoflon layer  1140 , and the first ground layer  1150  may be located on the bottom of the first nanoflon layer  1140  through the adhesion using an adhesive tape, an adhesive, or thermal adhesion in which heat is applied to an adhesive material. 
       FIG. 12  illustrates a second embodiment of the method of manufacturing the transmission line using the nanostructured material according to the present invention. Referring to  FIG. 12 , in the second embodiment with respect to the method of manufacturing the transmission line using the nanostructured material according to the present invention, when the first embodiment of the method of manufacturing the transmission line using the nanostructured material according to the present invention is formed as shown in  FIG. 11( c ) , ground lines  1210  and  1220  are further formed and the first pattern  1230  is used as a signal line. That is, the ground lines  1210  and  1220  and a signal line  1230  may be formed by etching the first conductor layer  1120 . 
       FIG. 13  illustrates a third embodiment of the method of manufacturing the transmission line using the nanostructured material according to the present invention.  FIG. 13( a )  illustrates the first embodiment, shown in  FIG. 11( c ) , with respect to the method of manufacturing the transmission line using the nanostructured material according to the present invention. As shown in  FIG. 13( b ) , a second nanoflon layer  1310  is located on a result of the first embodiment of the method of manufacturing the transmission line. For example, the second nanoflon layer  1310  may adhere ( 1315 ) to the first pattern  1130  formed on the first insulating layer  1120  and the first insulating layer  1110  exposed by etching in the first embodiment of the method of manufacturing the transmission line. Also, a second ground layer  1320  may be located on the second nanoflon layer  1310 . The second ground layer  1320  may be located on the second nanoflon layer  1310  through adhesion  1325 . The adhesion  1315  or  1325  may be performed using an adhesive or an adhesive or through thermal adhesion in which heat is applied to an adhesive tape. 
       FIG. 14  illustrates a fourth embodiment of the method of manufacturing the transmission line using the nanostructured material according to the present invention. As shown in  FIG. 14( b ) , a second nanoflon layer  1410  is located on a result of the second embodiment of the method of manufacturing the transmission line according to the present invention as shown in  FIG. 14( a )  and a second ground layer  1420  is located above the second nanoflon layer  1410 . The second nanoflon layer  1410  may be located on the ground lines  1210  and  1220 , the signal line  1230  and the first insulating layer  1110 , and the second ground layer  1420  may be located on the second nanoflon layer  1410  through adhesions  1415  and  1425 , respectively. 
       FIGS. 15 a , 15 b , and 15 c    illustrate a fifth embodiment of the method of manufacturing the transmission line using the nanostructured material according to the present invention.  FIG. 15 a    illustrates the shown in  FIG. 13( b )  and a result of the third embodiment of the method of manufacturing the transmission line according to the present invention. Referring to  FIG. 15 b   , a third nanoflon layer  1510  is located on the second ground layer  1320  of the result of the third embodiment of the method of manufacturing the transmission line according to the present invention as shown in  FIG. 13( b ) , and then a second insulating layer  1520  is located on the third nanoflon layer  1510 . 
     Referring to  FIG. 15 c   , a second conductive layer  1530  is formed above the second insulating layer  1520 , and then a second pattern  1540 , which is a signal line, is formed by etching the second conductive layer  1530 . The second ground layers  1320  and the second insulating layer  1520  which come into contact with the third nanoflon layer  1510  may adhere ( 1515  and  1525 ) thereto, respectively, using an adhesive tape or an adhesive or through thermal adhesion in which heat is applied to an adhesive material. 
       FIGS. 16 a , 16 b , 16 c , 16 d , and 16 e    illustrate a sixth embodiment of the method of manufacturing the transmission line using the nanostructured material according to the present invention.  FIG. 16 a    illustrates the shown in  FIG. 13( b )  and the result of the third embodiment of the method of manufacturing the transmission line according to the present invention. 
     Referring to  FIG. 16 b   , a third nanoflon layer  1610  is located on the second ground layer  1320  of the result of the third embodiment of the method of manufacturing the transmission line according to the present invention as shown in  FIG. 16   a.    
     Referring to  FIG. 16 c   , a first conductive layer  1630  is formed on a first insulating layer  1620 . Referring to  FIG. 16 d   , a second pattern  1640 , which transmits and receives a signal, is formed by etching the first conductor layer  1630 . In the etching, the first conductive layer  1630  may be etched using a product in which the first conductive layer  1630  is formed on the first insulating layer  1620 . 
     Referring to  FIG. 16 e   , the second insulating layer  1620 , on which the second pattern  1640  is formed as shown in  FIG. 16 d   , is located above the third nanoflon layer  1610  located on the second ground layer  1320  as shown in  FIG. 16 b   . The second ground layer  1320  and the second insulating layer  1620  which come into contact with the third nanoflon layer  1610  may adhere ( 1615  and  1625 ) thereto, respectively, using an adhesive tape or an adhesive or through thermal adhesion in which heat is applied to an adhesive material. 
       FIGS. 17 a  and 17 b    illustrate a seventh embodiment of the method of manufacturing the transmission line using the nanostructured material according to the present invention.  FIG. 17 a    illustrates the shown in  FIG. 15 b    and illustrates forming of the second conductive layer  1530  on the second insulating layer  1520  in the fifth embodiment of the method of manufacturing the transmission line according to the present invention. Referring to  FIG. 17 b   , the fifth embodiment of the method of manufacturing the transmission line according to the present invention is formed as shown in  FIG. 15 b   , and then a signal line  1730  and ground lines  1710  and  1720  are formed by etching the second conductive layer  1530 . 
       FIGS. 18 a , 18 b , 18 c , and 18 d    illustrate an eighth embodiment of the method of manufacturing the transmission line using the nanostructured material according to the present invention.  FIG. 18 a    illustrates the shown in  FIG. 16 b    and illustrates forming of the third nanoflon layer  1610  on the second ground layer  1320  in the third embodiment of the method of manufacturing the transmission line according to the present invention. Referring to  FIG. 18 b   , a first conductive layer  1820  is formed on a first insulating layer  1810 . Referring to  FIG. 18 c   , a second pattern  1830 , which transmits and receives a signal, and two ground lines  1840  and  1850  are formed by etching the first conductor layer  1820 . In the etching, the first conductive layer  1820  may be etched using a product in which the first conductive layer  1820  is formed on the first insulating layer  1810 . 
     Referring to  FIG. 18 d   , the first insulating layer  1810 , on which the second pattern  1830  and the ground lines  1840  and  1850  are formed as shown in  FIG. 18 c   , is located above the third nanoflon layer  1610  located on the second ground layer  1320  as shown in  FIG. 18 a   . The second ground layer  1320  and the first insulating layer  1810  which come into contact with the third nanoflon layer  1610  may adhere ( 1615  and  1825 ) thereto, respectively, using an adhesive tape or an adhesive or through thermal adhesion in which heat is applied to an adhesive material. 
       FIGS. 19 a  and 19 b    illustrate a ninth embodiment of the method of manufacturing the transmission line using the nanostructured material according to the present invention.  FIG. 19 a    illustrates the shown in  FIGS. 15 c  and 16 e    and illustrates results of the fifth and sixth embodiments of the method of manufacturing the transmission line using the nanostructured material according to the present invention. 
     Referring to  FIG. 19 b   , a fourth nanoflon layer  1910  is located on the second pattern  1540  formed in the fifth embodiment of the method of manufacturing the transmission line or the second pattern  1640  formed in the sixth embodiment of the method of manufacturing the transmission line and the second insulating layer  1520  or  1620  exposed by etching, and then a third ground layer  1920  is formed on the fourth nanoflon layer  1910 . Here, the fourth nanoflon layer  1910  may be located on the second pattern  1540  or  1640  and the second insulating layer  1520  or  1620  exposed by etching through adhesions  1915  and  1925  using an adhesive tape, an adhesive, or thermal adhesion in which heat is applied to an adhesive material. 
     According to the embodiments of the present invention, in a transmission line using a nanostructured material and a method of manufacturing the transmission line, a nanostructured material formed by electrospinning a resin at a high voltage is used as a dielectric of a transmission line such that the permittivity of the dielectric of the transmission line may be low and a loss tangent value may be reduced at the low permittivity. 
     Particularly, the transmission line using the nanostructured material may be used as a low-loss flat cable for reducing a transmission loss of a highfrequency signal in a band from 3.5 GHz and 28 GHz used in a five generation (5G) mobile communication network. 
     Although the embodiments of the present invention have been described with reference to the drawings, it should be understood that the embodiments are merely examples and a variety of modifications and equivalents thereof may be made by one of ordinary skill in the art. Therefore, the technical scope of the present invention should be defined by the technical concept of the attached claims.