The present invention relates to an antenna module, and more particularly, to an antenna module suitable for a 5G antenna in a millimeter wave band.
In 5G or higher (hereinafter, referred to as “5G”) communication developed as a next-generation communication, a low-dielectric/low-loss antenna module using a ceramic substrate and a magnetic sheet suitable for a millimeter wave (mmWave) frequency band is required. In addition, about 3% of the 5G antenna module radiation efficiency is lost due to heat issues, resulting in poor compatibility, so the need to solve the heat problem through the use of a dielectric and to solve the EMI noise through the use of a separate magnetic material is emerging.
In addition, the development of low dielectric/low-loss ultra-high frequency materials and antenna modules optimized for each application such as repeater/small cells, mobiles, and automobiles is being promoted. However, in order to commercialize such a 5G antenna module, it is urgent to improve heat generation and antenna efficiency of the chipset.
The present invention has been devised in view of the above problems, and is directed to providing an antenna module capable of improving antenna characteristics and efficiency in a 5G millimeter wave band by arranging a heat dissipation structure.
In addition, the present invention is directed to providing an antenna module capable of improving impedance matching by implementing a power feeding via electrode and a grounding via electrode in a coaxial line structure.
In order to solve the above problems, the present invention provides an antenna module, including: a radiation pattern that functions as an antenna; a base layer disposed on one side of the radiation pattern and implemented by stacking a plurality of low-temperature co-fired ceramic (LTCC) substrates to have a connection pattern electrically connected to the radiation pattern; an RF chipset electrically connected to the radiation pattern through the connection pattern to generate an RF signal to be transmitted from the radiation pattern or to process an RF signal received from the antenna; a thermal interface material (TIM) disposed at one side of the RF chipset to transfer heat generated from the RF chipset; a heat sink disposed at one side of the TIM to spread heat transferred from the TIM; and a fan disposed at one side of the heat sink to cool the heat sink by introducing outside air.
In addition, the connection pattern may include a power feeding via electrode penetrating the plurality of LTCC substrates.
In addition, the present invention may further include a grounding via electrode that penetrates a part of the base layer, is spaced apart from a side surface of the power feeding via electrode, and surrounds at least a portion of the side surface of the power feeding via electrode.
In addition, the grounding via electrode may be disposed to be spaced apart from the radiation pattern in a lower direction of a location of the radiation pattern, and may be not provided at the uppermost LTCC substrate of the base layer.
In addition, the grounding via electrode may be disposed to be spaced apart from the RF chipset in an upper direction of a location of the RF chipset, and may be not provided at a bottommost LTCC substrate of the base layer.
In addition, the power feeding via electrode may include first and second power feeding via electrodes each passing through a plurality of different LTCC substrates among the base layer, the first and second power feeding via electrodes may be provided at different plane positions of the base layer, and the connection pattern may further include a redistribution layer electrically connecting the first and second power feeding via electrodes.
In addition, the grounding via electrode may be disposed to be spaced apart from the redistribution layer in an upper and lower direction of a location of the redistribution layer, and may be not provided in LTCC substrates in contact with upper and lower portions of a LTCC substrate having the redistribution layer.
The grounding via electrode may be disposed to be spaced apart from the redistribution layer in an upper and lower direction of a location of the redistribution layer, and may be provided in a region excluding a corresponding portion of the redistribution layer in first and second LTCC substrates in contact with upper and lower portions of the LTCC substrate having the redistribution layer.
In addition, the present invention may further include a grounding member provided in at least one of LTCC substrates having a grounding via electrode, and electrically connecting the grounding via electrode to a ground.
The radiation pattern may emit millimeter wave (mmWave) radio waves.
According to the present invention, since the heating of the RF chipset can be effectively suppressed or cooled by disposing the TIM, the heat sink, the fan, and the like on the rear surface of the RF chipset, characteristics and efficiency in the 5G millimeter wave band can be improved.
In addition, according to the present invention, since a grounding via electrode and a power feeding via electrode are implemented in a coaxial line structure by configuring the grounding via electrode to be surrounded by the power feeding via electrode in a concentric structure, impedance matching can be improved and at the same time, isolation between power feeding circuits can be improved.
Hereinafter, exemplary embodiments of the present invention will be described in detail so that those of ordinary skill in the art can readily implement the present invention with reference to the accompanying drawings. The present invention may be embodied in many different forms and is not limited to the embodiments set forth herein. In the drawings, parts unrelated to the description are omitted for clarity of description of the present invention. Throughout the specification, like reference numerals denote like elements.
As shown in
The antenna cover 100 is a component for protecting an internal antenna element or the like, which is a portion exposed from the substrate 300, and may include a plastic material. The antenna cover 100 may include a portion through which millimeter waves are transmitted and a portion supporting the transmission portion. That is, the antenna cover 100 may transmit the millimeter waves transmitted from the internal antenna element to the outside or transmit the millimeter waves transmitted from another device to the inside.
The spacer 200 is disposed between a director 311 of the substrate 300 and the antenna cover 100. That is, the spacer 200 is a component for forming a space between the antenna cover 100 and the director 311 of the substrate 300. For example, in the spacer 200, a portion corresponding to the director 311 may be implemented in an open form.
The substrate 300 includes a plurality of base layers 310, 320, and 330 implemented as a low-temperature co-fired ceramic (LTCC) substrate and is disposed between the spacer 200 and the antenna RF chipset 400. In this case, each of the base layers 310, 320, and 330 may be formed by stacking at least one LTCC substrate. In addition, the first and second base layers 310 and 320 may include a conductive pattern of a conductive material. However, the third base layer 330 may also be a molding layer formed of an epoxy molding compound (EMC) or the like rather than the LTCC substrate.
For example, the conductive pattern may include a director 311, a radiation pattern 321 of an antenna function, a power feeding via electrode 322 and a redistribution layer 323 which are connection patterns for electrically connecting the radiation pattern 321 and the RF chipset 400, and a grounding via electrode 324 spaced apart from a periphery of the power feeding via electrode 322. In addition, the conductive pattern may further include grounding members 312, 325, 326, and 327. In this case, the grounding via electrode 324 and the grounding members 312, 325, 326, and 327 may be electrically connected to the ground. In addition, the director 311 and the radiation pattern 321 may be referred to as an antenna element. However, a detailed structure of each conductive pattern will be described below.
The RF chipset 400 includes an integrated circuit (IC) for transmitting and receiving RF signals. The RF chipset 400 may generate and process RF signals in a millimeter wave frequency band, and at least one RF chipset may be provided. For example, the RF chipset 400 may be disposed on one side of the substrate 300, that is, on the third base layer 330, and may transmit and receive RF signals for each antenna element through its own terminal. The RF signal generated by the RF chipset 400 may be emitted from the radiation pattern 321 via a terminal and a connection pattern of the RF chipset 400. In addition, the external RF signal received by the radiation pattern 321 may be transferred to a terminal of the RF chipset 400 via a connection pattern and processed by the RF chipset 400. Hereinafter, a structure including the substrate 300 and the RF chipset 400 is referred to as a “module substrate”.
The thermal interface material (TIM) 500 is formed of a heat transfer material and is provided on one side of the RF chipset 400, and may dissipate heat generated from the RF chipset 400 to the outside. That is, the TIM 500 is disposed between the RF chipset 400 and the heat sink 700 to transfer heat of the RF chipset 400 to the heat sink 700. The amount of heat transferred to the heat sink 700 may be increased by the TIM 500.
The evaluation board (EVB) 600 may be electrically connected to the RF chipset 400 to discharge various signals to the outside in order to evaluate the function of the antenna module 10. For example, the EVB 600 may include an RF signal input/output terminal for connection to the module substrate and a DC bias application terminal, and may evaluate and verify the performance of the module substrate.
The heat sink 700 may be disposed on one side of the TIM 500 to spread the emitted heat of the RF chipset 400 transferred from the TIM 500. That is, the heat sink 700 contacts the TIM 500 to absorb and dissipate heat transferred through the TIM 500. In this case, the fan 800 may be disposed on one side of the heat sink 700 to facilitate heat diffusion or cooling of the heat sink 700 by introducing external air into the heat sink 700.
The present invention may effectively suppress or cool the heat generation of the RF chipset 400 by disposing the TIM 500, the heat sink 700, and the fan 800 on the rear surface of the RF chipset 400, thereby improving characteristics and efficiency in the 5G millimeter wave band.
The antenna module 10 may have a radiation pattern 321 functioning as an antenna on the top surface of the substrate 300, and the antenna cover 100 may not be separately provided. That is, the overall size of the antenna module 10 may be miniaturized by disposing the RF chipset 400 on one side of the substrate 300 having the radiation pattern 321.
Hereinafter, a detailed structure of the substrate 300 (i.e., a detailed structure of each conductive pattern) will be described.
The substrate 300 may include a plurality of base layers 310, 320, and 330 stacked in turn, as shown in
The first base layer 310 is disposed at the outermost side (i.e., the uppermost side in
The director 311 may be formed in a shape corresponding to the radiation pattern 321 on the plane of the second base layer 320. For example, as shown in
Meanwhile, in
The second base layer 320 may be disposed in the lower portion of the first base layer 310. In this case, a plurality of radiation patterns 321 may be formed on the top surface of the second base layer 320. For example, a cavity may be formed in the lower portion of the first base layer 310, and the radiation pattern 321 may be disposed in the corresponding cavity. To this end, the first base layer 310 may be implemented as a plurality of LTCC substrates, and a corresponding cavity may be formed in at least a partial region of the bottommost LTCC substrate.
Meanwhile, the RF chipset 400 may be disposed on the bottom surface of the second base layer 320. In this case, the terminal of the RF chipset 400 may be electrically connected to the power feeding via electrode 322 of the connection pad exposed on the bottom surface of the second base layer 320. That is, the RF chipset 400 may be disposed in the upper portion of the third base layer 330. For example, a cavity is formed in the upper portion of the third base layer 330, and the RF chipset 400 may be protected by disposing the RF chipset 400 in the corresponding cavity. Alternatively, the RF chipset 400 may be protected by molding the third base layer 330, which is a molding layer, with respect to the RF chipset 400 disposed on the bottom surface of the second base layer 320. In addition, the power feeding via electrode 322, the redistribution layer 323, and the grounding via electrode 324 may be included in the second base layer 320. Additionally, the third and fourth grounding members 326 and 327 may also be included in the second base layer 320.
In particular, the grounding via electrode 324 should be disposed to be electrically insulated from the power feeding via electrode 322, the radiation pattern 321, the redistribution layer 323, and the RF chipset 400. That is, the grounding via electrode 324 should be spaced apart from the horizontal direction (side surface) of the power feeding via electrode 322 but not exposed on the upper and lower surfaces of the second-1 base layer 320a and the second-2 base layer 320b, and should be spaced apart up and down from the radiation pattern 321 and the terminal of the RF chipset 400 disposed in the upper or lower portion of the second base layer 320 and the redistribution layer 323 disposed inside the second base layer 320.
In order to correspond to each arrangement condition of the grounding via electrode 324, it may be preferable that the second base layer 320 is implemented by stacking a plurality of LTCC substrates. That is, it may be preferable that the second-1 base layer 320a is implemented in a form in which a plurality of LTCC substrates 320a-1, 320a-2, 320a-3, 320a-4, and 320a-5 are stacked, and the second-2 base layer 320b is implemented in a form in which a plurality of LTCC substrates 320b-1, 320b-2, 320b-3, 320b-4, and 320b-5 are stacked. However, the number of the plurality of LTCC substrates of the second-1 base layer 320a and the second-2 base layer 320b is not limited to the number of the substrates shown in the drawings. A more detailed description of each arrangement condition of the grounding via electrode 324 will be described later.
The power feeding via electrode 322 and the redistribution layer 323 are a connection pattern for electrically connecting the terminal of the RF chipset 400 to the radiation pattern 321 and transmit RF signals. In this case, the power feeding via electrode 322 is a conductive layer for transmitting RF signals in the vertical direction in
The redistribution layer 323 is a conductive layer for transmitting RF signals in the horizontal direction in
The grounding via electrode 324 is disposed to be spaced apart from a periphery of the power feeding via electrode 322. However, the grounding via electrode 324 needs to be electrically insulated from the power feeding via electrode 322. Accordingly, the grounding via electrode 324 is formed to be spaced apart from the power feeding via electrode 322 by a predetermined distance in the horizontal direction of
Since the wavelength of the millimeter wave frequency band is very short, the impedance matching is very difficult because the mutual influence between the connection patterns is very large. Accordingly, in the present invention, by disposing the spaced apart grounding via electrode 324 around the power feeding via electrode 322 through the above-described coaxial line structure, impedance matching with respect to the connection pattern can be easily achieved and at the same time, isolation between power feeding circuits can be improved.
For the structure of the coaxial line, in the at least one LTCC substrate of the second-1 base layer 320a, the first grounding via electrode 324a may be formed to penetrate the spaced portion around the first power feeding via electrode 322a with the penetration portion therebetween. In addition, in the at least one LTCC substrate of the second-2 base layer 320b, the second grounding via electrode 324b may be formed to penetrate the spaced portion around the second power feeding via electrode 322b with the penetration portion therebetween. In this case, the penetration portions of the first power feeding via electrode 322a and the second power feeding via electrode 322b may be formed at different positions on the plane of the LTCC substrate.
For example, as shown in
In addition, in some LTCC substrates 320b-1, 320b-2, 320b-3, and 320b-4 of the second-2 base layer 320b, the second grounding via electrode 324b may be formed in a spaced apart portion around the second power feeding via electrode 322b with a penetration portion therebetween. In this case, in the case of the LTCC substrates 320b-2, 320b-3, and 320b-4 of the second-1 base layer 320b, the second grounding via electrode 324b is formed so as to go all around the penetration portion of the second power feeding via electrode 322b. On the other hand, in the case of the LTCC substrates 320b-1 of the second-2 base layer 320b the second grounding via electrode 324b is formed only in a region except for the corresponding portion of the redistribution layer 323. This is because the second grounding via electrode 324b must not be in contact with not only the second power feeding via electrode 322b, but also the redistribution layer 323.
Meanwhile, as shown in
That is, unlike the case shown in
The grounding via electrode 324 needs to be electrically insulated from the radiation pattern 321 as well. Accordingly, the grounding via electrode 324 is formed to be spaced apart from the lower direction of the location of the radiation pattern 321 located at the uppermost part of the second base layer 320. For example, the grounding via electrode 324 may not be formed at the uppermost LTCC substrate 320a-1 of the second-1 base layer 320a.
The grounding via electrode 324 needs to be electrically insulated from the redistribution layer 323 as well. Accordingly, the grounding via electrode 324 is formed to be spaced apart from the upper and lower directions of the location of the redistribution layer 323. For example, in the LTCC substrates 320a-4 and 320a-5 of the second-1 base layer 320a and the LTCC substrate 320b-1 of the second-2 base layer 320b, the grounding via electrode 324 may not be formed or the grounding via electrode 324 may be formed only in a region except for a corresponding portion of the redistribution layer 323.
The grounding via electrode 324 needs to be electrically insulated from the RF chipset 400 as well. Accordingly, the grounding via electrode 324 is formed to be spaced apart from the upper direction of the location of the RF chipset 400 located at the bottommost part of the second base layer 320. For example, the grounding via electrode 324 may not be formed at the bottommost LTCC substrate 320b-5 of the second-2 base layer 320b.
In particular, since the power feeding via electrode 322 corresponds to a transmission line of an RF signal, it may be preferable that its thickness d2 is equal to or greater than a thickness d1 of the grounding via electrode 324. Of course, since the radiation pattern 321 needs to perform an antenna function, it is preferable that a diameter d3 of the radiation pattern 321 in a plane is greater than d1 and d2. Similarly, it is preferable that a diameter of the director 311 formed corresponding to the radiation pattern 321 in a plane is greater than d1 and d2.
Referring to
In addition, a second grounding member 325 may be additionally formed on the top surface of the second-1 base layer 320a in addition to the radiation pattern 321. The second grounding member 325 is disposed to be spaced apart from the radiation pattern 321 so as to be in non-contact with the radiation pattern 321 on the top surface of the second-1 base layer 320a. That is, a cavity C is formed between the second grounding member 325 and the radiation pattern 321 on the top surface of the first base layer 310. The second grounding member 325 may be disposed to surround the periphery of the radiation pattern 321 in a plane and may be electrically connected to a ground.
For reference, in
In addition, referring to
Meanwhile, in
In addition, in
Although exemplary embodiments of the present invention have been described above, the idea of the present invention is not limited to the embodiments set forth herein. Those of ordinary skill in the art who understand the idea of the present invention may easily propose other embodiments through supplement, change, removal, addition, etc. of elements within the scope of the same idea, but the embodiments will be also within the idea scope of the present invention.
The present invention relates to an antenna module, and can provide an antenna module suitable for a millimeter wave band, and thus has industrial applicability.
Number | Date | Country | Kind |
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10-2020-0184513 | Dec 2020 | KR | national |
10-2021-0174475 | Dec 2021 | KR | national |
Filing Document | Filing Date | Country | Kind |
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PCT/KR2021/018516 | 12/8/2021 | WO |