Antenna-in-package and electronic device comprising same

Abstract

The present invention relates to an antenna-in-package and a communication device comprising same, the antenna-in-package comprising: a first substrate on which a radio frequency integrated circuit (RFIC) is mounted; a second substrate on which a plurality of antenna elements are arranged; and an adhesive layer arranged between the first substrate and the second substrate. The present invention has excellent radiation performance in a limited space, and facilitates predicting of RF characteristics, thereby providing excellent mass productivity.

Description

Antenna-in-package and electronic device including same

[0001] The present invention relates to an antenna-in-package and an electronic device including the same.

[0002] The rapid growth in mobile traffic is driving the development of next-generation communications technologies based on high-bandwidth frequencies, such as 5G (5th generation) or WiGig (wireless gigabit alliance). For example, high-bandwidth signals may include millimeter waves, which operate in the 20 GHz to 300 GHz band. The use of high-band frequencies allows for smaller and lighter antennas and devices due to their shorter wavelengths.

[0003] Electronic devices use high-band frequencies, which allows for a relatively large number of antennas to be mounted on the same area due to the short wavelength. However, the straightness of radio waves increases, and the propagation path loss becomes severe, which may deteriorate the propagation characteristics.

[0004] For example, communication modules utilizing millimeter-wave bands exceeding 20 GHz often include small-sized antennas. Antenna mounting and other device structures may be positioned around the device where the antenna is placed, either in conjunction with the antenna or in a manner that obscures the antenna's signal radiation direction. Consequently, there is a growing need for the development of an antenna-in-package that can minimize propagation path loss and deliver superior radiation performance within a limited space.

[0005] The problem to be solved by the present invention is to provide an antenna-in-package with excellent radiation performance in a limited space and a communication device including the same.

[0006] To solve the aforementioned problem, the present invention provides an antenna-in-package comprising: a first substrate on which a radio frequency integrated circuit (RFIC) is mounted; a second substrate on which a plurality of antenna elements are arranged; and an adhesive layer arranged between the first substrate and the second substrate. Optionally, the present invention may further include a third substrate arranged between at least one of the plurality of antenna elements and the second substrate.

[0007] In addition, the present invention provides an electronic device including the above-described antenna-in-package.

[0008] The antenna-in-package according to the present invention has excellent mass production because RF characteristics are easy to predict, and has excellent communication coverage in a limited space.

[0009] FIG. 1 is a cross-sectional view schematically showing an antenna-in-package according to a first embodiment of the present invention.

[0010] Figure 2 is an enlarged cross-sectional view of the dotted box area (X) of Figure 1.

[0011] FIG. 3 is a cross-sectional view schematically showing an antenna-in-package according to a second embodiment of the present invention.

[0012] <Explanation of symbols>

[0013] 100: 1st substrate, 110: 1st copper foil,

[0014] 200: Second substrate, 200A: First flat surface,

[0015] 200B: bend, 200C: second flat,

[0016] 210: Second copper foil, 300: Adhesive layer,

[0017] 310: VIA, 400: RFIC,

[0018] 500: antenna element, 600: connector,

[0019] 700A, 700B: Third board

[0020] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. These embodiments of the present invention are provided to more fully explain the present invention to those skilled in the art. The following embodiments may be modified in various ways, and the scope of the present invention is not limited to the following embodiments. Throughout this specification, the same reference numerals denote the same structures.

[0021] Unless otherwise defined, all terms (including technical and scientific terms) used herein may be used in their common sense to those of ordinary skill in the art to which the present invention pertains. Furthermore, terms defined in commonly used dictionaries are not to be interpreted ideally or excessively unless explicitly and specifically defined otherwise.

[0022] Furthermore, the sizes and thicknesses of each component shown in the drawings are arbitrarily indicated for convenience of explanation, and thus the present invention is not necessarily limited to the illustrated components. In the drawings, the thicknesses are enlarged to clearly represent various layers and regions. Furthermore, in the drawings, the thicknesses of some layers and regions are exaggerated for convenience of explanation.

[0023] Additionally, throughout the specification, whenever a part is said to "include" a component, this does not mean that it excludes other components, but rather that it may include other components, unless otherwise specifically stated.

[0024] Additionally, throughout the specification, “above” or “on” means not only being located above or below the target part, but also including cases where there is another part in between, and does not necessarily mean being located above with respect to the direction of gravity.

[0025] In addition, the terms “first”, “second”, etc. in this specification are not used to indicate any order or importance, but are used to distinguish between components.

[0026]

[0027] Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. 1 and 2.

[0028] FIG. 1 is a cross-sectional view schematically showing an antenna-in-package according to a first embodiment of the present invention, and FIG. 2 is an enlarged cross-sectional view of a dotted box portion (X) of FIG. 1.

[0029] As illustrated in FIG. 1, the antenna-in-package (AiP) of the present invention includes a first substrate (100); a second substrate (200) and an adhesive layer (300) interposed therebetween.

[0030] The first substrate (100) is a substrate on which a radio frequency integrated circuit (RFIC) (400) is placed. Not only the RFIC, but also BFIC, active and passive components can be mounted on the first substrate (100) through package balls (e.g., BGA, LGA), and a connector (600) can also be placed on the first substrate (100).

[0031] For example, the first substrate may be a multilayer printed circuit board (PCB), specifically a multilayer printed circuit board for radio frequency, more specifically a multilayer printed circuit board for mmWAVE.

[0032] For example, the first substrate (100) may be a multilayer printed circuit board, although not shown, including: a first core layer; a plurality of first insulating layers built up on one or both sides of the core layer; a plurality of first circuit pattern layers disposed between the first core layer and the first insulating layer and between the first insulating layers; and a first via formed through the first insulating layer and electrically connecting the first circuit pattern layers. Optionally, the first circuit pattern layer may be disposed on the first insulating layer as the outermost layer. However, the first core layer may be replaced with the first insulating layer.

[0033] The material forming the first circuit pattern layer is not particularly limited as long as it is a conductive material commonly known in the art, and examples thereof include copper (Cu), aluminum (Al), silver (Ag), tin (Sn), gold (Au), nickel (Ni), lead (Pb), titanium (Ti), or alloys thereof. The first circuit pattern layer may perform various functions depending on the design of the layer, and may be, for example, a power supply line, a ground line, a ground electrode, etc. The first circuit pattern layer (e.g., a power supply line) may be electrically connected to a radio frequency integrated circuit (RFIC) (400) disposed on a first substrate (100). In addition, an end of any one of the plurality of first circuit pattern layers may be electrically connected to a connector (600) disposed on the first substrate (100).

[0034] The first core layer and the first insulating layer may be insulating materials commonly known in the art, for example, polymers such as epoxy resin, polyimide, polyester, polypropylene oxide, polyphenylene oxide, phenol resin, liquid crystal polymer, fluorine resin, etc., or may be a prepreg formed by mixing the polymer with an inorganic filler, or impregnating the polymer and the inorganic filler into a core material such as glass fiber. In one example, the first core layer may be a prepreg layer, and the first insulating layer may be an epoxy resin layer or a phenol resin layer.

[0035] This first substrate (100) may be a rigid printed circuit board, specifically a rigid multilayer printed circuit board. If the first substrate is a flexible printed circuit board, warpage of the substrate may occur or reliability may be reduced, so it is appropriate for the first substrate to be a rigid printed circuit board.

[0036] In addition, the first substrate (100) may be a printed circuit board, specifically a multilayer printed circuit board, made of a material having a relatively high dielectric constant (Dk) and dielectric loss tangent (Df) compared to the second substrate (200) and having an overall thickness at least three times thicker than the second substrate (200) in order to secure rigidity. For example, the difference in dielectric constant (Dk) between the first substrate and the second substrate may be in the range of about 1 to 1.5, and the difference in dielectric loss tangent (Df) between the first substrate and the second substrate may be in the range of about 0.001 to 0.0014. In one example, the first substrate may have a relative permittivity (Dk) in the range of about 3 to 4 and a dielectric loss factor (Df) in the range of about 0.001 to 0.005, and the second substrate may have a relative permittivity (Dk) in the range of about 2 to less than 3 and a dielectric loss factor (Df) in the range of about 0.0002 to 0.0003. Here, the relative permittivity and the dielectric loss factor are each measured by a probe station in the 28 GHz band.

[0037] The second substrate (200) is an antenna substrate on which a plurality of antenna elements (500) are arranged, and is electrically connected to the antenna elements (500).

[0038] The second substrate (200) may be a single-layer or multi-layer substrate. For example, when the second substrate (200) is a multi-layer substrate, although not shown, it may include a second core layer; a plurality of second insulating layers built up on one or both sides of the second core layer; a plurality of second circuit pattern layers disposed between the second core layer and the second insulating layer and between the second insulating layers; and a second via formed through the second insulating layer and electrically connecting the second circuit pattern layers. Optionally, the second circuit pattern layer may be disposed on the second insulating layer as the outermost layer. However, the second core layer may be replaced with the second insulating layer.

[0039] Since the material forming the second circuit pattern layer is the same as that of the first circuit pattern layer, it is omitted. The second circuit pattern layer can perform various functions depending on the design of the layer, and can be, for example, a feed line, a ground line, a ground electrode, etc. This second circuit pattern layer (e.g., a feed line) can be electrically connected to an antenna element (500) disposed on a second substrate (200).

[0040] The second core layer and the second insulating layer may be insulating materials commonly known in the art. Since the description of the insulating material is the same as that described for the first substrate, it is omitted. However, the second core layer and the second insulating layer may be made of a different material from at least one of the first core layer and the first insulating layer of the first substrate (100). According to one example, the second core layer and the second insulating layer may each be a resin layer formed of a material selected from the group consisting of a polyimide resin, a polyester, and a fluorine-based resin. According to another example, the second core layer, the second insulating layer, or both may be resin layers formed of a resin having a high curing temperature, such as about 250 to 350°C (e.g., a fluorine-based resin, etc.).

[0041] This second substrate (200) is a substrate made of a different material from the first substrate (100), and may be, for example, a flexible substrate, specifically, a flexible multilayer printed circuit board. In particular, if the second substrate (200) is a flexible substrate that is longer than the first substrate and has excellent bending characteristics, it can radiate signals in two different directions, such as horizontal and vertical directions. For example, the second substrate (200) may be a flexible substrate having a flexural strength of about 500 to 1000 times according to the JIS C 6471 test method. Here, the flexural strength was tested according to the JIS C 6471 test method, and the test conditions were a load of 0.5 kgf at a thickness of 50 ㎛, a speed of 175 cpm (cycles per minute), an angle of 135 °, and a radius of 0.38 mm.

[0042] The second substrate (200) may be L-shaped and include non-linear or curved portions. In this case, the antenna-in-package of the present invention can radiate signals in two different directions, such as horizontal and vertical, thereby improving communication coverage characteristics.

[0043] According to an example, the second substrate (200) may include a first flat portion (200A) having a portion of one surface overlapping the first substrate (100) and having one or more first antenna elements (500) arranged thereon; a curved portion (200B) extending and curved from the first flat portion (200A); and a second flat portion (200C) extending from the curved portion (200B) and having one or more second antenna elements arranged thereon. At this time, the bending angle of the curved portion (200B) may be about 45 to 90°. In particular, since the first flat portion (200A) and the second flat portion (200C) are arranged at positions orthogonal to each other, signals can be radiated in two directions that are 90° apart.

[0044] The adhesive layer (300) is disposed between the first substrate (100) and the second substrate (200) to attach (bond) the first substrate (100) and the second substrate (200), thereby integrating the first substrate (100) and the second substrate (200). In this way, the present invention mounts the second substrate (200) on the first substrate (100) through the adhesive layer (300), so that the bonding area is larger compared to the case of applying a package ball (e.g., BGA), and thus is superior in terms of reliability, and thus mass productivity can be improved.

[0045] The adhesive usable in the present invention is not particularly limited as long as it is an adhesive known in the art, and may be, for example, a bonding sheet, and may be bonded at a temperature of about 150 to 190°C.

[0046] The bonding sheet usable in the present invention is not particularly limited as long as it is generally known in the art, and specifically, as long as it can bond two substrates at a temperature of about 150 to 190°C, it is not limited.

[0047] For example, the bonding sheet may include a substrate layer and an adhesive resin layer laminated on both sides of the substrate layer. The substrate layer may be made of polyimide (PI), polyethylene terephthalate (PET), polyethylene (PE), or the like, and may be polyimide (PI) as an example. The main resin of the adhesive resin layer may be an epoxy resin, an acrylic resin, or the like.

[0048] As another example, the bonding sheet may include first and second release substrates, and an adhesive resin layer interposed therebetween. The first and second release substrates may be polyethylene terephthalate (PET), etc., and the main resin of the adhesive resin layer may be epoxy resin, acrylic resin, etc. Such a bonding sheet is used with the first and second release substrates removed.

[0049] In addition, the thickness of the adhesive layer (100) is not particularly limited. However, the dielectric constant (Df) may vary depending on the thickness of the adhesive layer (100), and the thinner the adhesive layer (100), the more miniaturized and lightweight the antenna-in-package can be. Therefore, it is appropriate to adjust the thickness of the adhesive layer (100) to a range of about 10 to 50 μm.

[0050] This adhesive layer (300) may include a plurality of vias (310) formed to penetrate in the thickness direction. Through each of the vias (310), the first substrate (100) and the second substrate (200) may be electrically connected, and ultimately, the RFIC (400) on the first substrate (100) and the antenna element (500) on the second substrate (200) may be electrically connected. Meanwhile, in the present invention, even in a portion where the via (310) is not present, the first substrate (100) and the second substrate (200) may transmit a signal through electrical mutual coupling, and thus, the RFIC (400) and the antenna element (500) may be electrically connected.

[0051] The above via (310) can be formed through a via formation process commonly known in the art. For example, a via hole such as a PTH (Plating Through Hole) or an LVH (Laser Via Hole) can be formed by using a method such as etching or laser drilling, and then plating the inner wall of the via hole.

[0052] In addition, as illustrated in FIG. 2, the first substrate (100) may further include a first copper foil (110) disposed on a surface in contact with the adhesive layer (300), and the second substrate (200) may further include a second copper foil (210) disposed on a surface in contact with the adhesive layer (300). At this time, in order to prevent interference with the flow of radio waves, the first and second copper foils (110, 210) may be arranged in the form of a circuit pattern, with a portion (e.g., a portion around a power supply portion) etched. In this case, the present invention can minimize a delamination phenomenon at the bonding interface. At this time, both the first and second copper foils (110, 210) may be low-contrast copper foils. For example, the first and second copper foils (110, 210) may each have a 10-point average roughness (Rz) in the range of about 1 to 2 ㎛.

[0053] The antenna-in-package of the present invention may additionally include a radio frequency integrated circuit (RFIC) (400), as illustrated in FIG. 1.

[0054] The RFIC (400) is a circuit that generates an RF signal to be radiated through the antenna element (500), and may be one or more. The RFIC (400) is placed (mounted) on the first substrate (100) through a package ball (e.g., BGA, LGA), etc., and is electrically connected to the first substrate (100). At this time, the first substrate (100) may be connected to the second substrate (200) in a direct power supply manner through a via (310) of the adhesive layer (300), as described above, or may be connected to the second substrate (200) in a coupling power supply manner to transmit a signal. Accordingly, the RFIC (400) may be electrically connected to each antenna element (500) through each power supply line in the first and second substrates (100, 200), or may be electrically connected to each antenna element (500) in a coupling power supply manner, thereby transmitting a high-frequency signal.

[0055] Although not shown, the antenna-in-package of the present invention may additionally include a beamforming integrated circuit (BFIC) when the antenna is a beamforming antenna in which a plurality of antenna elements are arranged to implement beamforming.

[0056] One or more BFICs (not shown) are placed (mounted) on the first substrate (100) through a package ball (e.g., BGA, LGA) and are electrically connected to the first substrate (100). These BFICs (not shown), like the RFIC (400), may be electrically connected to each antenna element (500) through each feed line in the first and second substrates (100, 200), or may be electrically connected to each antenna element (500) through a coupling feed method.

[0057] The antenna-in-package of the present invention may further include a connector (600) disposed on the first substrate (100) and electrically connected to the first substrate (100), as illustrated in FIG. 1. When the antenna-in-package is disposed within a communication device, the connector (600) may be connected to a coaxial cable or a flexible printed circuit board (FPCB: Flexible PCB), etc., to provide a physical and / or electrical connection path with other components within the communication device. The material or shape of the connector (600) is not particularly limited, and those commonly known in the art may be applied.

[0058] The antenna-in-package of the present invention may include a plurality of antenna elements (500), as illustrated in FIG. 1.

[0059] The antenna element (500) transmits and / or receives RF (radio frequency) signals, and can transmit and receive, for example, signals of millimeter wavelength (mmWave). Although not shown, the antenna element (500) includes at least one antenna pattern, a feed line for transmitting a signal to the antenna pattern, and a ground. The antenna pattern may be referred to as a radiating unit. The feed line may have a strip-line structure, a microstrip structure, or an embedded coplanar waveguide line structure. The antenna element (500) is electrically connected to the RFIC (400) through the feed line in the first and second substrates (100, 200), and can receive a signal from the RFIC (400) and radiate the signal, or transmit the received signal to the RFIC (400).

[0060] According to an example, the plurality of antenna elements (500) may include one or more first antenna elements (500A) disposed on a first flat portion (200A) of the second substrate (200); and one or more second antenna elements (500B) disposed on a second flat portion (200C) of the second substrate (200). In this case, the first flat portion (200A) is disposed to extend along a main surface of the first substrate (100), and the second flat portion (200C) is disposed to extend along a side surface of the first substrate (100). Therefore, since the first antenna element (500A) and the second antenna element (500B) can radiate signals in two different directions, such as vertical and horizontal directions, respectively, the antenna-in-package of the present invention can have improved communication coverage.

[0061] Hereinafter, an antenna-in-package according to a second embodiment of the present invention will be described with reference to FIG. 3. To avoid duplication, descriptions of components already described will be omitted.

[0062] An antenna-in-package according to a second embodiment of the present invention, as illustrated in FIG. 3, includes a first substrate (100); a second substrate (200); an adhesive layer (300) interposed therebetween; and one or more third substrates (700) disposed on the second substrate. In addition, the antenna-in-package of the present invention may further include an RFIC (400) disposed on the first substrate (100), a plurality of antenna elements (500) disposed on the second substrate (200), and a connector (600) disposed on the first substrate, as illustrated in FIG. 3. In addition, although not illustrated, the antenna-in-package of the present invention may further include a BFIC (not illustrated) disposed on the first substrate (100).

[0063] The first substrate (100), second substrate (200), adhesive layer (300), RFIC (400), antenna element (500), connector (600), and BFIC (not shown) are each the same as those described in the first embodiment, and therefore are omitted.

[0064] The third substrate (700) is a substrate disposed between at least one of the plurality of antenna elements (500) and the second substrate (200), and may be a single-layer or multi-layer substrate. By disposing the antenna element (500) through the third substrate (700), the distance between the antenna element (500) and the ground electrode (not shown) in the second substrate (200) increases, thereby widening the frequency bandwidth of the antenna element, and thus, the antenna-in-package of the present invention can implement wideband characteristics.

[0065] The material of the third substrate may be a rigid substrate, a flexible substrate, or a rigid-flexible substrate.

[0066] For example, when the third substrate (700) is a rigid substrate, the third substrate (700) can be mounted on the second substrate (200) through a package ball (e.g., BGA, LGA).

[0067] As another example, when the third substrate (700) is a rigid substrate, the third substrate (700) may be mounted on the second substrate (200) via a second adhesive layer (not shown). The description of the second adhesive layer is omitted because it is the same as that described for the adhesive layer of the first embodiment.

[0068] As another example, when the third substrate (700) is a flexible substrate, the third substrate (700) may be directly attached to the surface of the second substrate (200) and mounted. At this time, the method of mounting the third substrate may include stacking the third substrate (700) on the second substrate (200) and then attaching the third substrate (700) on the second substrate (200) through a high-temperature, high-pressure press process. According to an example, the high-temperature, high-pressure press process may be performed at a temperature of about 150 to 190° C. and a pressure of about 25 to 40 kgf / cm. 2 The laminate of the second substrate and the third substrate can be integrated by thermally pressing the laminate for about 2 to 5 hours under pressure.

[0069] The third substrate (700) can transmit a signal through a via formed at the interface with the second substrate (200). In addition, the third substrate (700) can also transmit a signal through electrical mutual coupling with the second substrate (200).

[0070] Meanwhile, the present invention provides an electronic device including the aforementioned antenna-in-package.

[0071] Examples of the electronic devices may include portable communication devices (e.g., smartphones), computer devices, portable multimedia devices, portable medical devices, cameras, wearable devices, or home appliances.

[0072] For example, a portable communication device may include the aforementioned antenna-in-package and a BBIC (Baseband Integrated Circuit) that constitutes a baseband signal processing circuit. The portable communication device may up-convert a signal transmitted from the BBIC to the antenna-in-package into a high-frequency signal and radiate the signal from the antenna element, and down-convert a high-frequency signal received from the antenna element and process the signal in the BBIC.

Claims

1. A first substrate on which a radio frequency integrated circuit (RFIC) is mounted; a second substrate on which a plurality of antenna elements are arranged; and An adhesive layer disposed between the first substrate and the second substrate Antenna-in-package including.

2. In paragraph 1, The first substrate includes a first copper foil disposed on a surface in contact with the adhesive layer, An antenna-in-package, wherein the second substrate includes a second copper foil disposed on a surface in contact with the adhesive layer.

3. In paragraph 2, An antenna-in-package, wherein the first and second copper foils each have a 10-point average roughness (Rz) in the range of 1 to 2 ㎛.

4. In paragraph 1, An antenna-in-package, wherein the second substrate is composed of a different material from the first substrate.

5. In paragraph 1, An antenna-in-package, wherein the first substrate has a higher dielectric constant (Dk) and dielectric loss factor (Df) than the second substrate.

6. In paragraph 1, The difference in dielectric constant (Dk) between the first substrate and the second substrate is in the range of 1 to 1.5, An antenna-in-package, wherein the dielectric constant (Df) difference between the first substrate and the second substrate is in the range of 0.001 to 0.0014.

7. In paragraph 1, The above first substrate has a dielectric constant (Dk) in the range of 3 to 4 and a dielectric factor (Df) in the range of 0.001 to 0.005, An antenna-in-package, wherein the second substrate has a dielectric constant (Dk) of 2 or more and less than 3 and a dielectric factor (Df) in the range of 0.001 to 0.

004.

8. In paragraph 1, An antenna-in-package, wherein the second substrate is a flexible substrate having a flexural strength of 500 to 1000 times at a thickness of 50 ㎛ according to the JIS C 6471 test method.

9. In paragraph 1, The above second substrate A first flat portion, a portion of which overlaps the first substrate and on which one or more first antenna elements are arranged; a bent portion extended from the first flat portion; and A second flat portion extending from the above-mentioned bent portion and having one or more second antenna elements arranged thereon. An antenna-in-package, comprising:

10. In paragraph 9, An antenna-in-package, wherein the first flat portion and the second flat portion are arranged at positions orthogonal to each other.

11. In paragraph 1, An antenna-in-package, wherein the adhesive layer includes a plurality of vias formed penetrating in the thickness direction.

12. In paragraph 1, An antenna-in-package, wherein the first substrate and the second substrate transmit signals through electrical mutual coupling.

13. In paragraph 1, An antenna-in-package further comprising a radio frequency integrated circuit (RFIC) disposed on the first substrate.

14. In paragraph 1, An antenna-in-package further comprising a plurality of antenna elements arranged on the second substrate.

15. In paragraph 14, An antenna-in-package, further comprising a third substrate disposed between at least one of the plurality of antenna elements and the second substrate.

16. In paragraph 15, The above third substrate is a rigid substrate, An antenna-in-package, wherein the third substrate is mounted on the second substrate through a package ball.

17. In paragraph 15, The above third substrate is a rigid substrate, An antenna-in-package, wherein the third substrate is mounted on the second substrate through a second adhesive layer.

18. In paragraph 15, The above third substrate is a flexible substrate, An antenna-in-package, wherein the third substrate is mounted directly attached to the surface of the second substrate.

19. In Article 15, An antenna-in-package, wherein the second substrate and the third substrate transmit signals through electrical mutual coupling.

20. An electronic device comprising an antenna-in-package as claimed in any one of claims 1 to 19.

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