Circuit board and antenna device including same

Abstract

The circuit board according to the embodiment includes an insulating layer and a circuit pattern layer disposed on the insulating layer, the circuit pattern layer including an antenna pattern for transmitting and receiving antenna signals, and the 10-point average surface roughness Rz of the surface of the antenna pattern is in the range of 0.2 μm to 0.5 μm.

Description

[Technical field]

[0001] The embodiments relate to a circuit board and an antenna device including the circuit board. [Background technology]

[0002] In recent years, efforts have been made to develop improved 5G (fifth generation) or pre-5G communication systems to meet the demands of wireless data traffic.

[0003] To achieve high data transmission rates, 5G communication systems use ultra-high frequency (mmWave) bands (sub6 GHz, 28 GHz, 38 GHz or higher). These high frequency bands are called mmWave due to the length of their wavelengths.

[0004] In order to mitigate the path loss of radio waves in the ultra-high frequency band and increase the transmission distance of radio waves, integration technologies such as beamforming, massive MIMO, and array antennas are being developed in 5G communication systems.

[0005] FIG. 1 is a diagram showing an antenna device.

[0006] 1, the antenna device according to the comparative example includes a plurality of substrates, that is, a first substrate 10 corresponding to an antenna portion and a second substrate 20 corresponding to a drive portion.

[0007] At this time, the second substrate 20 is manufactured through a process separate from that of the first substrate 10. For example, in a comparative example, the first substrate 10 and the second substrate 20 are manufactured through separate processes, and a process of combining them is performed through this. The second substrate 20 includes a driving element.

[0008] At this time, the first substrate 10 and the second substrate 20 of the comparative example are bonded by the solder balls 30. The solder balls 30 have a structure that covers the molding layer 40.

[0009] At this time, in the antenna device of the comparative example, the first substrate 10 and the second substrate 20 are joined in a state of being vertically aligned. And, the antenna package substrate of the comparative example has a structure in which the first substrate 10 and the second substrate 20 are connected via the solder balls 30 disposed between them.

[0010] As a result, in the comparative example, since the first substrate 10 and the second substrate 20 are interconnected through the solder balls 30, there is a problem in that the thickness of the antenna package substrate increases by the height of the solder balls 30.

[0011] Furthermore, in the comparative example, as described above, the first substrate 10 and the second substrate 20 have a vertically stacked structure and are interconnected via the solder balls 30, which increases the signal transmission length, and as the transmission length (e.g., signal transmission distance) becomes longer, there is a problem that signal loss increases.

[0012] In addition, in the comparative example, the first board 10 and the second board 20 are connected to each other in a connector structure using another flexible circuit board (not shown) instead of the solder balls 30. However, when the first board 10 and the second board 20 are electrically connected to each other using the flexible circuit board, the first board and the second board have a horizontal arrangement structure, and the signal transmission distance increases by the length of the flexible circuit board, which increases signal loss. Summary of the Invention [Problem to be solved by the invention]

[0013] The embodiments provide a circuit board with improved antenna characteristics and an antenna device including the same.

[0014] Furthermore, the embodiments provide a circuit board capable of reducing the surface roughness of the antenna pattern, and an antenna device including the same.

[0015] Also, the embodiments provide a circuit board capable of minimizing the difference between the top width and bottom width of the antenna pattern, and an antenna device including the same. [Means for solving the problem]

[0016] The circuit board according to the embodiment includes an insulating layer and a circuit pattern layer disposed on the insulating layer, the circuit pattern layer including an antenna pattern for transmitting and receiving antenna signals, and the 10-point average surface roughness Rz of the surface of the antenna pattern is in the range of 0.2 μm to 0.5 μm.

[0017] The antenna pattern also includes an upper surface and a lower surface opposite to the upper surface, and the width of the upper surface of the antenna pattern is smaller than the width of the lower surface of the antenna pattern.

[0018] In addition, the width of the upper surface of the antenna pattern is 95% or more of the width of the lower surface of the antenna pattern.

[0019] Moreover, the difference between the width of the upper surface and the width of the lower surface of the antenna pattern satisfies the range of 0.5 μm to 1.2 μm.

[0020] In addition, the antenna pattern includes an upper surface, a lower surface opposite to the upper surface, and a side surface connecting the upper surface and the lower surface, and a horizontal distance between one end of the upper surface of the antenna pattern connected to the side surface of the antenna pattern and one end of the lower surface of the antenna pattern satisfies the range of 0.25 μm to 0.6 μm.

[0021] The side surface of the antenna pattern includes a curved surface.

[0022] The etching factor of the antenna pattern is 40 or more, and is determined by the following formula: Etching factor = Antenna pattern thickness / (Width of lower surface of antenna pattern - Width of upper surface of antenna pattern)

[0023] The antenna pattern also includes a first metal layer disposed on the insulating layer, and a second metal layer disposed on the first metal layer and containing a metal different from that of the first metal layer.

[0024] The first metal layer includes nickel and chromium, and the second metal layer includes copper.

[0025] In addition, the insulating layer is divided horizontally into a first region and a second region, the antenna pattern includes a first antenna pattern arranged in the first region of the insulating layer and a second antenna pattern arranged in the second region of the insulating layer, the number of layers in the first region of the insulating layer is greater than the number of layers in the second region of the insulating layer, and the second region of the insulating layer is folded based on the first region of the insulating layer.

[0026] Additionally, the first region of the insulating layer includes the same insulating material as the second region of the insulating layer, and the insulating material includes a liquid crystal polymer (LCP).

[0027] On the other hand, an antenna device according to an embodiment includes an insulating layer including a first region and a second region that can be bent from the first region, a first antenna pattern arranged in the first region of the insulating layer, a second antenna pattern arranged in the second region of the insulating layer, a first pad arranged in the first region of the insulating layer, a second pad arranged in the first region of the insulating layer, a first connection portion arranged on the first pad, a second connection portion arranged on the second pad, a communication element mounted on the first connection portion and coupled to the first and second antenna patterns, and a power element mounted on the second connection portion and coupled to the first and second antenna patterns, and the 10-point average surface roughness Rz of each of the surfaces of the first and second antenna patterns is in the range of 0.2 μm to 0.5 μm.

[0028] Further, each of the first and second antenna patterns includes an upper surface and a lower surface opposite to the upper surface, the width of the upper surface being smaller than the width of the lower surface, and the width of the upper surface being 95% or more of the width of the lower surface.

[0029] Moreover, the difference between the width of the upper surface and the width of the lower surface satisfies the range of 0.5 μm to 1.2 μm.

[0030] Further, the first and second antenna patterns include an upper surface, a lower surface opposite the upper surface, and a side surface connecting the upper surface and the lower surface, and a horizontal distance between one end of the upper surface and one end of the lower surface connected to one end and the other end of the side surface, respectively, satisfies the range of 0.25 μm to 0.6 μm.

[0031] The antenna pattern also includes a first metal layer disposed on the insulating layer and including nickel and chromium, and a second metal layer disposed on the first metal layer and including copper.

[0032] Additionally, the first region of the insulating layer includes the same insulating material as the second region of the insulating layer, and the insulating material includes a liquid crystal polymer (LCP). Effect of the Invention

[0033] The embodiment can provide a circuit board with improved antenna characteristics and an antenna device including the same.

[0034] Specifically, the circuit board of the embodiment includes a circuit pattern layer corresponding to the antenna pattern. The circuit pattern layer includes a first metal layer, which is a thin film layer including a first metal, and a second metal layer including a second metal disposed on the first metal layer. In this case, the embodiment forms the second metal layer using the first metal layer. As a result, the embodiment can minimize damage to the second metal layer that occurs during the etching process of the first metal layer.

[0035] As a result, the 10-point average surface roughness Rz of the surface of the circuit pattern layer of the embodiment is in the range of 0.2 μm to 0.5 μm. The difference between the upper surface width and the lower surface width of the circuit pattern layer of the embodiment satisfies the range of 0.5 μm to 1.2 μm. The upper surface width of the circuit pattern layer of the embodiment is 95% or more of the lower surface width of the circuit pattern layer. Furthermore, the horizontal distance W1 between one end of the upper surface connected to the side surface of the circuit pattern layer of the embodiment and one end of the lower surface satisfies the range of 0.25 μm to 0.6 μm. Furthermore, the etching factor of the circuit pattern layer of the embodiment is 40 or more.

[0036] At this time, if the difference between the upper surface width and the lower surface width of the circuit pattern layer is less than 0.5 μm, plating properties may be reduced in the process of forming the circuit pattern layer 120. For example, if the difference between the upper surface width and the lower surface width of the circuit pattern layer is less than 0.5 μm, a problem may occur in which plating is not complete down to the lower region of the dry film in the plating process. As a result, an undercut may be formed on the lower surface of the circuit pattern layer, resulting in a problem of degraded communication characteristics of the circuit board.

[0037] In addition, if the difference between the top width and the bottom width of the circuit pattern layer is greater than 1.2 μm, the frequency bandwidth of the signal transmitted by the circuit pattern layer may decrease. Specifically, the frequency bandwidth of the signal increases as the difference between the top width and the bottom width decreases. In addition, if the difference between the top width and the bottom width of the circuit pattern layer is greater than 1.2 μm, the frequency bandwidth decreases as shown in the comparative example of FIG. 11, which may cause a problem of degraded communication characteristics of the circuit board.

[0038] Furthermore, if the upper surface width of the circuit pattern layer is less than 95% of the lower surface width of the circuit pattern layer, as described above, plating properties may decrease during the process of forming the circuit pattern layer, which may result in the formation of an undercut on the lower surface of the circuit pattern layer.

[0039] In addition, if the horizontal distance W1 of the circuit pattern layer of the embodiment is less than 0.25 μm, the plating property may be reduced in the process of forming the circuit pattern layer, which may result in the formation of an undercut on the lower surface of the circuit pattern layer, as described above. In addition, if the horizontal distance W1 of the circuit pattern layer of the embodiment exceeds 0.6 μm, the frequency bandwidth may be reduced, which may result in the communication characteristics of the circuit board being degraded, as described above.

[0040] Furthermore, if the etching factor of the circuit pattern layer is less than 40, the difference between the top and bottom widths of the circuit pattern layer and / or the horizontal distance W1 may deviate from the target range, which may result in problems of reduced plating ability or reduced frequency bandwidth.

[0041] As a result, the circuit board and the antenna device including the circuit board of the embodiment can reduce signal transmission loss that occurs in the process of transmitting a high frequency band signal. Furthermore, the circuit board and the antenna device including the circuit board of the embodiment can improve the frequency bandwidth.

[0042] The circuit board of the embodiment includes a first region and a second region that are horizontally spaced apart from each other and include first and second antenna pattern layers, respectively. The second region is a flexible region that can be bent relative to the first region. A communication element connected to the first and second antenna pattern layers is disposed in the first region. The first and second antenna pattern layers emit antenna signals in different directions. The communication element controls the first and second antenna pattern layers. In this way, the embodiment can control a plurality of antenna pattern layers that emit antenna signals in different directions using one communication element. In this way, the embodiment can miniaturize the antenna device. [Brief description of the drawings]

[0043] [Figure 1] FIG. 13 is a diagram showing an antenna device of a comparative example.

[0044] [Diagram 2] FIG. 2 is a diagram showing an antenna substrate according to an embodiment of the present invention.

[0045] [Diagram 3] FIG. 2 is a cross-sectional view showing the layer structure of a circuit pattern layer and a through electrode of an embodiment.

[0046] [Figure 4] 1 is a scanning electron microscope (SEM) photograph showing the roughness of a circuit pattern layer of a comparative example.

[0047] [Diagram 5] 1 is a scanning electron microscope (SEM) photograph showing the roughness of a circuit pattern layer in an example.

[0048] [Figure 6] 4 is a scanning electron microscope (SEM) photograph for explaining the side shape and etching factor of a circuit pattern layer of a comparative example.

[0049] [Figure 7]4 is a scanning electron microscope (SEM) photograph for explaining the side shape and etching factor of the circuit pattern layer in the example.

[0050] [Figure 8] 1 is a scanning electron microscope (SEM) photograph showing the surface of a circuit pattern layer of a comparative example.

[0051] [Figure 9] 2 is a scanning electron microscope (SEM) photograph showing the surface of a circuit pattern layer of an example.

[0052] [Figure 10] FIG. 11 is a diagram showing signal characteristics depending on the roughness of a circuit pattern layer.

[0053] [Figure 11] FIG. 13 is a diagram illustrating a frequency bandwidth of a circuit board of a comparative example.

[0054] [Figure 12] FIG. 13 is a diagram showing a frequency bandwidth of a circuit board according to an embodiment.

[0055] [Figure 13] 1 is a diagram showing an antenna device according to an embodiment;

[0056] [Figure 14] 14 is a diagram showing a part of a terminal device to which the antenna device of FIG. 13 is applied. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0057] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings.

[0058] However, the technical concept of the present invention is not limited to the embodiments described, but may be embodied in various different forms, and one or more of the components of the embodiments may be selectively combined or substituted within the scope of the technical concept of the present invention.

[0059] Furthermore, unless otherwise clearly defined and described, terms (including technical and scientific terms) used in the embodiments of the present invention may be interpreted as having a meaning that would be commonly understood by a person having ordinary knowledge in the technical field to which the present invention belongs, and commonly used terms, such as terms defined in a dictionary, may be interpreted in light of the contextual meaning of the relevant art.

[0060] In addition, the terms used in the embodiments of the present invention are intended to describe the embodiments and are not intended to limit the present invention. In the present specification, the singular form can include the plural form unless otherwise specified in the text, and when it is described as "A and (and) at least one (or more) of B and C", it can include one or more of all combinations that can be combined with A, B, and C.

[0061] In addition, in describing components of the embodiments of the present invention, terms such as first, second, A, B, (a), (b), etc. may be used. Such terms are merely used to distinguish the components from other components, and do not limit the nature, order, or sequence of the components. Furthermore, when a component is described as being "coupled," "coupled," or "connected" to another component, it may include not only the case where the component is directly coupled, coupled, or connected to the other component, but also the case where the component is "coupled," "coupled," or "connected" between the other component and the other component or by another component.

[0062] In addition, when described as being formed or located "above or below" each component, "above" or "below" includes not only the case where two components are in direct contact with each other, but also the case where one or more other components are formed or located between the two components. In addition, when described as "above or below," it can include not only the upper direction based on one component, but also the lower direction.

[0063] FIG. 2 is a diagram showing an antenna substrate according to the embodiment.

[0064] Referring to FIG. 2, the antenna substrate includes an insulating layer 110 , a circuit pattern layer 120 , a through electrode 130 , and a protective layer 140 .

[0065] The insulating layer 110 is made up of multiple layers.

[0066] For example, the insulating layer 110 may include a first insulating layer 111, a second insulating layer 112, and a third insulating layer 113. Although the insulating layer 110 is shown to be composed of three layers in Fig. 2, the embodiment is not limited thereto. The insulating layer 110 may have two or less layers, or may have four or more layers.

[0067] The insulating layer 110 has a flexible characteristic. The insulating layer 110 may be made of polyimide (PI). Alternatively, the insulating layer 110 may be made of liquid crystal polymer (LCP). However, the embodiment is not limited thereto. For example, the insulating layer 110 may be made of an insulating material that does not include glass fiber, such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polycarbonate (PC), polyethersulfone (PES), or polyacrylate (PAR).

[0068] Preferably, the insulating layer 110 of the embodiment is made of a liquid crystal polymer (LCP). When the insulating layer 110 is made of a liquid crystal polymer (LCP), the dielectric constant of the insulating layer 110 can be easily adjusted, and the insulating layer 110 can have a dielectric constant that can minimize signal transmission loss in a high frequency band. Furthermore, when the insulating layer 110 is made of a liquid crystal polymer (LCP), the manufacturing processability of the circuit board can be improved, and the overall thickness of the circuit board can be reduced.

[0069] As a result, the insulating layer 110 is bent with a curved surface in part. That is, the insulating layer 110 may be bent with a flat surface in part and a curved surface in part. In particular, the insulating layer 110 may be bent with a curved surface at an end, or may be bent or folded with a surface including a random curvature.

[0070] The circuit board includes a circuit pattern layer 120 .

[0071] The circuit pattern layer 120 includes a first circuit pattern layer 121, a second circuit pattern layer 122, a third circuit pattern layer 123, and a fourth circuit pattern layer .

[0072] The circuit pattern layer 120 includes an antenna pattern that functions as an antenna, for example, the circuit pattern layer 120 includes an antenna signal pattern, which functions to transmit an antenna signal and a data signal.

[0073] Thus, the circuit pattern layer 120 can be realized by, but is not limited to, a patch antenna. For example, the circuit pattern layer 120 can be realized by a dipole antenna. Also, the circuit pattern layer 120 can be realized by a combination of a patch antenna and a dipole antenna.

[0074] The circuit pattern layer 120 further includes a ground pattern and a power pattern.

[0075] The circuit pattern layer 120 includes a highly conductive metal material, for example, copper (Cu), aluminum (Al), silver (Ag), tin (Sn), gold (Au), nickel (Ni), lead (Pb), titanium (Ti), or an alloy thereof.

[0076] The circuit board includes a through electrode 130 .

[0077] The through electrode 130 includes a first through electrode 131, a second through electrode 132, and a third through electrode 133. The first through electrode 131 penetrates the first insulating layer 111. The second through electrode 132 penetrates the second insulating layer 112. The third through electrode 133 penetrates the third insulating layer 113. The through electrode 130 electrically connects between circuit pattern layers arranged in different layers. The through electrode 130 may include the same material as the circuit pattern layer 120. The through electrode 130 may have a tapered shape.

[0078] The circuit board includes a protective layer 140 .

[0079] The protective layer 140 includes a first protective layer 141 disposed on a lower surface of the first insulating layer 111. The protective layer 140 also includes a second protective layer 142 disposed on an upper surface of the third insulating layer 113. The protective layer 140 may be, but is not limited to, a solder resist.

[0080] The circuit board of the present application has antenna characteristics superior to those of the circuit board of the comparative example.

[0081] This is accomplished by the properties of the circuit pattern layer 120 included in the embodiment of the present application.

[0082] That is, the surface roughness of the circuit pattern layer 120 of the embodiment is lower than that of the circuit pattern layer of the comparative example, thereby enabling the circuit board of the embodiment to reduce signal transmission loss that occurs in the process of transmitting high frequency band signals.

[0083] In addition, the vertical cross-sectional shape of the circuit pattern layer 120 included in the examples of the present application is close to a square shape. For example, the side of the circuit pattern layer 120 of the examples is close to a right angle to the bottom surface of the circuit pattern layer 120. For example, the side of the circuit pattern layer 120 of the examples is close to a straight line. In contrast, the side of the circuit pattern layer of the comparative example is close to a curve. This can also be expressed as the difference between the upper surface width and the lower surface width of the circuit pattern layer 120. That is, the difference between the upper surface width and the lower surface width of the circuit pattern layer 120 of the examples is smaller than the difference between the upper surface width and the lower surface width of the circuit pattern layer of the comparative example. This can also be expressed as the etching factor of the circuit pattern layer. The etching factor is the value obtained by dividing the thickness of the circuit pattern layer by the difference between the upper surface width and the lower surface width of the circuit pattern layer. And, the difference between the upper surface width and the lower surface width of the circuit pattern layer 120 of the examples is close to 0. As a result, the etching factor of the circuit pattern layer 120 of the examples is higher than the etching factor of the circuit pattern layer of the comparative example.

[0084] As a result, the circuit board of the embodiment can increase the frequency bandwidth. That is, as shown in FIG. 11, it was confirmed that the frequency bandwidth available for signal transmission of the circuit pattern layer 120 decreases when the difference between the upper surface width and the lower surface width of the circuit pattern layer 120 increases or the etching factor of the circuit pattern layer 120 decreases. In addition, the embodiment can increase the frequency bandwidth available for use in products to which the circuit board is applied by increasing the etching of the circuit pattern layer 120 while decreasing the difference between the upper surface width and the lower surface width of the circuit pattern layer 120 compared to the comparative example due to the characteristics described below. This will be described in more detail below.

[0085] The etching factor of the circuit pattern layer of the embodiment is higher than the etching factor of the circuit pattern layer of the comparative example.

[0086] For example, embodiment circuit boards can provide wide bandwidth antenna patterns.

[0087] The circuit pattern layer 120 having the above-mentioned characteristics will be specifically described below.

[0088] FIG. 3 is a cross-sectional view showing the layer structure of a circuit pattern layer and a through electrode of the embodiment.

[0089] 3, the circuit pattern layer 120 includes a plurality of metal layers. The circuit pattern layer 120 includes a first metal layer 120a disposed on the insulating layer 110 and a second metal layer 120b disposed on the first metal layer 120a. The first metal layer 120a and the second metal layer 120b include different metal materials.

[0090] The first metal layer 120a includes nickel and chromium. The first metal layer 120a may be an alloy layer of nickel and chromium. Alternatively, the first metal layer 120a may include a nickel layer and a chromium layer.

[0091] The first metal layer 120a is deposited on the insulating layer 110 by a sputtering method. Thus, the first metal layer 120a may be formed on the insulating layer 110 as a thin film.

[0092] The second metal layer 120b is an electrolytic plating layer formed by electrolytic plating using the first metal layer 120a as a seed layer. The second metal layer 120b includes a metal material different from that of the first metal layer 120a. For example, the second metal layer 120b may include copper.

[0093] Furthermore, the through electrode 130 has a layer structure corresponding to the layer structure of the circuit pattern layer 120. That is, the through electrode 130 includes a first metal layer 130a and a second metal layer 130b. The first metal layer 130a of the through electrode 130 includes nickel and chromium. The second metal layer 130b of the through electrode 130 may include a metal different from the first metal layer 130a, such as copper.

[0094] In this embodiment, the circuit pattern layer 120 includes a first metal layer 120a and a second metal layer 120b which are different metal materials. The first metal layer 120a is a thin film layer formed by sputtering. Thus, in the embodiment, damage to the second metal layer 120b that occurs during etching of the first metal layer 120a, which is a seed layer, during the process of forming the circuit pattern layer 120 can be minimized.

[0095] That is, in the embodiment, the first metal layer 120a includes a different metal material than the second metal layer 120b, so that the second metal layer 120b is not etched during the etching process of the first metal layer 120a. Furthermore, in the embodiment, the first metal layer 120a is a thin film layer, so that the second metal layer 120b is not etched during the etching process of the first metal layer 120a.

[0096] As a result, the surface roughness of the circuit pattern layer 120, the difference between the upper surface width and the lower surface width of the circuit pattern layer 120, and the etching factor of the circuit pattern layer 120 are superior to those of the comparative example.

[0097] The differences in characteristics of the circuit pattern layers between the examples and the comparative examples will be described below.

[0098] FIG. 4 is a scanning electron microscope (SEM) photograph showing the roughness of the circuit pattern layer of the comparative example, and FIG. 5 is a scanning electron microscope (SEM) photograph showing the roughness of the circuit pattern layer of the example.

[0099] Referring to FIG. 4, the circuit board of the comparative example includes an insulating layer 11 and a circuit pattern layer 14 disposed on the insulating layer 11. The circuit pattern layer 14 of the comparative example is formed by electrolytic plating using a copper foil layer or a chemical copper plating layer containing copper as a seed layer. As a result, in the circuit pattern layer 14 of the comparative example, the electrolytically plated metal layer is also etched during the etching of the seed layer. As a result, the surface roughness of the circuit pattern layer 14 of the comparative example has a relatively high value. In addition, in the circuit pattern layer 14 of the comparative example, the line width and interval of the multiple circuit patterns are determined taking into consideration the etching of the electrolytically plated metal layer.

[0100] The 10-point average surface roughness Rz of the surface of the circuit pattern layer 14 of the comparative example is 1 μm to 1.5 μm. The circuit board of the comparative example is difficult to apply to products using high frequency bands. That is, as the frequency used in the application to which the circuit board is applied increases, the signal flow moves to the surface of the conductor (circuit pattern layer) due to the skin effect. When the maximum height roughness Ry of the circuit pattern layer 14 exceeds 1 μm as in the comparative example, the signal transmission loss increases in the high frequency band (mmWave). Therefore, the circuit board of the comparative example has a problem that the characteristics of the signal transmitted through the circuit pattern layer 14 are degraded.

[0101] Furthermore, the line width of the plurality of circuit patterns in the circuit pattern layer 120 of the comparative example is on the order of 60 μm, and the interval between the circuit patterns is on the order of 70 μm. As a result, the circuit board of the comparative example has a problem of low circuit integration.

[0102] Referring to FIG. 5, the circuit board of the embodiment includes an insulating layer 110 and a circuit pattern layer 120. The circuit pattern layer 120 includes a first metal layer 120a containing nickel and chromium, and a second metal layer 120b containing copper, as described above. The first metal layer 120a is a thin film layer. As a result, the embodiment can prevent the second metal layer 120b from being etched in the process of etching the first metal layer 120a. Therefore, the embodiment can reduce the 10-point average surface roughness Rz, line width, and spacing of the circuit pattern layer 120 compared to the comparative example.

[0103] Specifically, the maximum height roughness Ry of the surface of the circuit pattern layer 120 of the embodiment is 0.8 μm or less. Preferably, the 10-point average surface roughness Rz of the surface of the circuit pattern layer 120 of the embodiment is 0.7 μm or less. More preferably, the 10-point average surface roughness Rz of the surface of the circuit pattern layer 120 is 0.5 μm or less.

[0104] That is, the 10-point average surface roughness Rz of the surface of the circuit pattern layer 120 of the embodiment is in the range of 0.2 μm to 0.5 μm. Preferably, the 10-point average surface roughness Rz of the surface of the circuit pattern layer 120 of the embodiment is 0.2 μm to 0.45 μm or less. More preferably, the 10-point average surface roughness Rz of the circuit pattern layer 120 of the embodiment is 0.2 μm to 0.4 μm.

[0105] If the 10-point average surface roughness Rz of the surface of the circuit pattern layer 120 is less than 0.2 μm, the adhesion between the circuit pattern layer 120 and the insulating layer 110 will decrease, which may result in the problem of the circuit pattern layer 120 peeling off from the insulating layer 110.

[0106] In addition, if the 10-point average surface roughness Rz of the surface of the circuit pattern layer 120 exceeds 0.5 μm, signal transmission loss may increase due to a skin effect. That is, if the 10-point average surface roughness Rz of the surface of the circuit pattern layer 120 exceeds 0.5 μm, it may be difficult to apply the circuit pattern layer 120 to products using high frequency bands.

[0107] As described above, the embodiment can reduce the 10-point average surface roughness Rz of the surface of the circuit pattern layer 120 compared to the comparative example, thereby improving the characteristics of signals transmitted through the circuit board.

[0108] Furthermore, the line width of the circuit patterns of the circuit pattern layer 120 of the embodiment is in the range of 4 μm to 10 μm. Moreover, the interval between the circuit patterns of the circuit pattern layer 120 of the embodiment is in the range of 6 μm to 14 μm. That is, the line width and interval of the circuit pattern layer 120 of the embodiment are 20% or less of the line width and interval of the circuit pattern layer 14 of the comparative example. As a result, the embodiment can improve the circuit integration of the circuit board. Furthermore, the embodiment can increase the layout area of ​​the circuit pattern layer 120 in the same space, thereby improving the characteristics of the signal transmitted through the antenna pattern.

[0109] FIG. 6 is a scanning electron microscope (SEM) photograph for explaining the side shape and etching factor of the circuit pattern layer of the comparative example, and FIG. 7 is a scanning electron microscope (SEM) photograph for explaining the side shape and etching factor of the circuit pattern layer of the example.

[0110] 6, the circuit pattern layer 14 of the comparative example includes an upper surface 14T and a side surface 14S. The side surface 14S of the circuit pattern layer 14 of the comparative example has a curved surface or curved line in vertical cross section. In other words, the circuit pattern layer 14 of the comparative example has a large difference between the upper surface width and the lower surface width. The circuit pattern layer 14 of the comparative example also has low line straightness. The circuit pattern layer 14 of the comparative example also has a low etching factor.

[0111] The difference between the upper surface width and the lower surface width of the circuit pattern layer 14 of the comparative example exceeds 13 μm. For example, the upper surface width of the circuit pattern layer 14 of the comparative example is 80% or less of the lower surface width of the circuit pattern layer 14. The line straightness of the circuit pattern layer 14 of the comparative example exceeds 0.68 μm. In this case, the line straightness means the straightness of the side surface 14S of the circuit pattern layer 14. The line straightness can also be expressed as 1 / 2 of the difference between the upper surface width and the lower surface width. That is, the line straightness means the horizontal distance w1 between one end of the upper surface 14T connected to the side surface 14S of the circuit pattern layer 14 and one end of the lower surface. The horizontal distance w1 of the circuit pattern layer 14 of the comparative example exceeds 0.68 μm.

[0112] Furthermore, the etching factor of the circuit pattern layer 14 of the comparative example is about 12. Here, the etching factor is a value obtained by dividing the thickness of the circuit pattern layer 14 by the difference between the upper surface width and the lower surface width of the circuit pattern layer 14. The lower the etching factor, the greater the difference between the upper surface width and the lower surface width of the circuit pattern layer 14.

[0113] 7, the circuit pattern layer 120 of the embodiment includes an upper surface 120T and a side surface 120S. The side surface 120S of the circuit pattern layer 120 of the embodiment has a linear shape that is substantially close to vertical in a vertical cross section. In other words, the difference between the upper surface width and the lower surface width of the circuit pattern layer 120 of the embodiment is lower than that of the comparative example. In addition, the line straightness of the circuit pattern layer 120 of the embodiment is superior to that of the comparative example. In addition, the etching factor of the circuit pattern layer 14 of the embodiment is higher than that of the comparative example.

[0114] The difference between the upper surface width and the lower surface width of the circuit pattern layer 120 in the embodiment is 1.2 μm or less, 1.0 μm or less, or 0.7 μm or less. Specifically, the difference between the upper surface width and the lower surface width of the circuit pattern layer 120 in the embodiment satisfies the range of 0.5 μm to 1.2 μm.

[0115] If the difference between the upper and lower widths of the circuit pattern layer 120 is less than 0.5 μm, plating properties in the process of forming the circuit pattern layer 120 may be reduced. For example, the circuit pattern layer 120 is formed by a plating process. Here, the plating process means a process of filling an opening of a dry film (not shown) with a metal material. The difference between the upper and lower widths of the circuit pattern layer 120 corresponds to the difference between the upper and lower widths of the opening. Here, plating can be performed completely up to the bottom region of the opening only when the plating process is performed with the inner wall of the opening tapered. If the difference between the upper and lower widths of the circuit pattern layer 120 is less than 0.5 μm, it may mean that plating is not performed completely in the bottom region of the opening in the plating process. For example, if the difference between the upper and lower widths of the circuit pattern layer 120 is less than 0.5 μm, an undercut may occur on the bottom surface of the circuit pattern layer 120, which may cause a problem of degraded signal characteristics.

[0116] Furthermore, if the difference between the top and bottom widths of the circuit pattern layer 120 is greater than 1.2 μm, the frequency bandwidth of the signal transmitted by the circuit pattern layer 120 may decrease. Specifically, the frequency bandwidth of the signal may increase as the difference between the top and bottom widths decreases. This will be described with reference to FIGS. 11 and 12. Furthermore, if the difference between the top and bottom widths of the circuit pattern layer 120 is greater than 1.2 μm, the frequency bandwidth may decrease as in the comparative example of FIG. 11, which may degrade the communication characteristics of the circuit board.

[0117] That is, the upper surface width of the circuit pattern layer 120 in the embodiment is 95% or more, further 96% or more, and further 98% or more of the lower surface width of the circuit pattern layer 120. If the upper surface width of the circuit pattern layer 120 is less than 95% of the lower surface width of the circuit pattern layer 120, as described above, plating properties may be reduced in the process of forming the circuit pattern layer 120. As a result, an undercut may be formed on the lower surface of the circuit pattern layer 120.

[0118] In addition, the horizontal distance W1 between one end of the upper surface 120 connected to the side surface 120 of the circuit pattern layer 120 of the embodiment and one end of the lower surface is 0.6 μm or less, 0.5 μm or less, or 0.35 μm or less. Specifically, the horizontal distance W1 of the circuit pattern layer 120 of the embodiment satisfies the range of 0.25 μm to 0.6 μm. If the horizontal distance W1 of the circuit pattern layer 120 of the embodiment is less than 0.25 μm, as described above, the plating property may be reduced in the process of forming the circuit pattern layer 120, and therefore an undercut may be formed on the lower surface of the circuit pattern layer 120. If the horizontal distance W1 of the circuit pattern layer 120 of the embodiment exceeds 0.6 μm, the frequency bandwidth may be reduced as described above, which may result in a deterioration in the communication characteristics of the circuit board.

[0119] Furthermore, the etching factor of the circuit pattern layer 120 in the embodiment is 40 or more.

[0120] If the etching factor of the circuit pattern layer 120 is less than 40, the difference between the upper and lower widths of the circuit pattern layer 120 and / or the horizontal distance W1 may deviate from the target range, which may result in problems of reduced plating ability or reduced frequency bandwidth.

[0121] FIG. 8 is a scanning electron microscope (SEM) photograph showing the surface of the circuit pattern layer of the comparative example, and FIG. 9 is a scanning electron microscope (SEM) photograph showing the surface of the circuit pattern layer of the example.

[0122] 8, the circuit pattern layer 14 of the comparative example includes an upper surface 14T, a side surface 14S, and a lower surface 14B. It can be seen that the circuit pattern layer 14 of the comparative example has the upper surface 14T, the side surface 14S, and the lower surface 14B that are considerably rough due to the characteristics of the seed layer.

[0123] 9, the circuit pattern layer 120 of the embodiment includes an upper surface 120T, a side surface 120S, and a lower surface 120B. It can be seen that the circuit pattern layer 120 of the comparative example has a significantly smoother upper surface 120T, a side surface 120S, and a lower surface 120B than the comparative example due to the characteristics of the seed layer.

[0124] FIG. 10 is a diagram showing signal characteristics depending on the roughness of the circuit pattern layer.

[0125] 10, the 10-point average surface roughness Rz of the circuit pattern layer 120 of the embodiment is lower than the 10-point average surface roughness Rz of the circuit pattern layer 14 of the comparative example. This confirms that the embodiment has a lower signal loss S21 (dB / mm) in the same frequency range compared to the comparative example.

[0126] Specifically, looking at the first signal loss characteristic C in FIG. 10, it can be seen that a signal loss of about −0.148 dB / mm occurs in the 28 GHz frequency band.

[0127] 10, it can be seen that the second signal loss characteristic E1 and the third signal loss characteristic E2 cause lower signal loss than the first signal loss characteristic C. The second signal loss characteristic E1 shows the signal loss when the 10-point average surface roughness Rz of the circuit pattern layer 120 is 0.3 μm, and the third signal loss characteristic E2 shows the signal loss when the 10-point average surface roughness Rz is 0.2 μm.

[0128] Looking at the second signal loss characteristic E1, it was confirmed that the signal loss occurring in the same frequency band (28 GHz) was about 0.0237 dB lower than that of the first signal loss characteristic C of the comparative example.

[0129] Looking at the third signal loss characteristic E2, it was confirmed that the signal loss was about 0.0445 dB lower than that of the first signal loss characteristic C of the comparative example in the same frequency band (28 GHz).

[0130] FIG. 11 is a diagram showing the frequency bandwidth of the circuit board of the comparative example, and FIG. 12 is a diagram showing the frequency bandwidth of the circuit board according to the embodiment.

[0131] With reference to FIG. 11, it was confirmed that, based on the frequency band where the signal loss is −6 dB or less, the comparative example can use a frequency band of 27.3 GHz to 30.7 GHz.

[0132] 12, it was confirmed that, based on the frequency band where the signal loss is −6 dB or less, the frequency band of 26.8 GHz to 30.8 GHz can be used in the embodiment. In other words, it was confirmed that the frequency band usable with the circuit board of the embodiment is wider than the frequency band usable with the circuit board of the comparative example.

[0133] As a result, the embodiment can provide a circuit board having antenna characteristics with a wider bandwidth than the comparative example.

[0134] FIG. 13 is a diagram showing an antenna device according to an embodiment, and FIG. 14 is a diagram showing a part of a terminal to which the antenna device of FIG. 13 is applied.

[0135] 13, the antenna device includes a circuit board. The circuit board includes an insulating layer 210, a circuit pattern layer 220, a through electrode 230, and a protective layer 240. The circuit board of the embodiment has already been described in FIG. 2, so a detailed description thereof will be omitted.

[0136] The circuit board of the embodiment is divided horizontally into a number of regions.

[0137] The circuit board includes a first region R1 and a second region R2. Each of the first region R1 and the second region R2 of the circuit board includes the insulating layer 210, the circuit pattern layer 220, the through electrode 230, and the protective layer 240.

[0138] Here, the first region R1 refers to a rigid region of the circuit board having rigid characteristics, and the second region R2 refers to a flexible region of the circuit board having flexible characteristics.

[0139] In this case, the insulating layer included in the first region R1 is the same as the insulating layer included in the second region R2. In the embodiment, the number of insulating layers in the first region R1 and the second region R2 is made different. As a result, the first region R1 having a relatively large number of layers has rigid characteristics, and the second region R2 having a relatively small number of layers has flexible characteristics.

[0140] Therefore, the second region R2 of the circuit board can be bent with respect to the first region R1, which allows the antenna device to transmit antenna signals in different directions.

[0141] Specifically, the circuit pattern layer 220 includes a first antenna pattern layer 220a included in a first region R1 of the circuit board, and the first antenna pattern layer 220a may emit an antenna signal in a first direction from a structure 300 (e.g., a terminal case) on which the antenna device is mounted.

[0142] The circuit pattern layer 220 further includes a second antenna pattern layer 220b included in a second region R2 of the circuit board. The second antenna pattern layer 220b may emit an antenna signal in a second direction different from the first direction from a structure 300 on which the antenna device is mounted. In this case, the first direction may be, but is not limited to, a direction perpendicular to the second direction.

[0143] The structure 300 refers to a main body 300 that forms the exterior of a terminal.

[0144] For example, the antenna device of the embodiment is disposed in a terminal, where the terminal may be any one of a mobile phone, a mobile phone, a smart phone, a portable smart device, a digital camera, a laptop computer, a digital broadcasting terminal, a PDA (Personal Digital Assistant), a PMP (Portable Multimedia Player), and a navigation device.

[0145] The terminal includes a main body 300, a display unit (not shown), and an antenna device of the embodiment disposed within the main body 300.

[0146] The body 300 forms the exterior of the terminal. As an example, the body 300 may have a rectangular parallelepiped shape. As another example, the body 300 may be formed to be at least partially rounded. The antenna device of the embodiment is disposed on the body 300. A display unit is disposed on one surface of the body.

[0147] That is, the main body 300 includes a plurality of outer surfaces. For example, the main body 300 includes a front surface on which the display unit is disposed, a rear surface opposite to the front surface, and a plurality of side surfaces between the front surface and the rear surface.

[0148] In the antenna device of the embodiment, the first region R1 and the second region R2 are bent so as to be disposed on at least two of the plurality of outer surfaces of the body 300.

[0149] For example, the body 300 may include four sides, and the first region R1 of the antenna device may be disposed on a first side of any one of the four sides, and the second region R2 may be disposed on a second side connected to the first side of the four sides.

[0150] Alternatively, the first region R1 of the antenna device may be disposed on the rear surface, and the second region R2 may be disposed on any one of the four side surfaces connected to the rear surface.

[0151] However, the first region R1 of the antenna device of the embodiment is a rigid region in which at least one element is mounted, and is arranged on the rear surface of the main body 300 in order to secure an arrangement space and improve the reliability of the element.

[0152] In addition, in the embodiment, the antenna device can be used without bending the first region R1 and the second region R2. In this case, the first antenna pattern layer 220a and the second antenna pattern layer 220b radiate antenna signals in the same first or second direction at positions spaced apart from each other.

[0153] Meanwhile, the circuit pattern layer 220 includes a plurality of pads, including a first pad 220c and a second pad 220d.

[0154] The first pad 220c and the second pad 220d refer to a circuit pattern layer disposed on the outermost layer of the circuit board. The first pad 220c and the second pad 220d are disposed in a first region R1 of the circuit board. In this case, the first pad 220c and the second pad 220d are shown to be disposed on the uppermost side of the circuit board, but are not limited thereto. For example, one of the first pad 220c and the second pad 220d may be disposed on the uppermost side of the circuit board, and the other may be disposed on the lowermost side of the circuit board.

[0155] A first connection part 250 is disposed on the first pad 220c. Also, a second connection part 260 is disposed on the second pad 220d. The first connection part 250 and the second connection part 260 may be, but are not limited to, solder balls.

[0156] A first element 270 is disposed on the first connection portion 250. And, a second element 280 is disposed on the second connection portion 260.

[0157] The first element 270 is a communication element RFIC. The first element 270 is connected to the first antenna pattern layer 220a and the second antenna pattern layer 220b, respectively. Thus, in the embodiment, one first element 270 can be used to control the first antenna pattern layer 220a and the second antenna pattern layer 220b, which emit antenna signals to different regions.

[0158] The second element 280 is a power supply element PMIC. The second element 280 is electrically connected to the first element 270. The second element 280 receives a control signal transmitted from the first element 270. The second element 280 controls power supplied to the first antenna pattern layer 220a and the second antenna pattern layer 220b based on the received control signal.

[0159] The embodiment can provide a circuit board with improved antenna characteristics and an antenna device including the same.

[0160] Specifically, the circuit board of the embodiment includes a circuit pattern layer corresponding to the antenna pattern. The circuit pattern layer includes a first metal layer, which is a thin film layer including a first metal, and a second metal layer including a second metal disposed on the first metal layer. In this case, the embodiment forms the second metal layer using the first metal layer. As a result, the embodiment can minimize damage to the second metal layer that occurs during the etching process of the first metal layer.

[0161] As a result, the 10-point average surface roughness Rz of the surface of the circuit pattern layer of the embodiment is in the range of 0.2 μm to 0.5 μm. The difference between the upper surface width and the lower surface width of the circuit pattern layer of the embodiment satisfies the range of 0.5 μm to 1.2 μm. The upper surface width of the circuit pattern layer of the embodiment is 95% or more of the lower surface width of the circuit pattern layer. Furthermore, the horizontal distance W1 between one end of the upper surface connected to the side surface of the circuit pattern layer of the embodiment and one end of the lower surface satisfies the range of 0.25 μm to 0.6 μm. Furthermore, the etching factor of the circuit pattern layer of the embodiment is 40 or more.

[0162] As a result, the circuit board and the antenna device including the circuit board of the embodiment can reduce signal transmission loss that occurs in the process of transmitting a high frequency band signal. Furthermore, the circuit board and the antenna device including the circuit board of the embodiment can improve the frequency bandwidth.

[0163] The circuit board of the embodiment includes a first region and a second region that are horizontally spaced apart from each other and include first and second antenna pattern layers, respectively. The second region is a flexible region that can be bent relative to the first region. A communication element connected to the first and second antenna pattern layers is disposed in the first region. The first and second antenna pattern layers emit antenna signals in different directions. The communication element controls the first and second antenna pattern layers. In this way, the embodiment can control a plurality of antenna pattern layers that emit antenna signals in different directions using one communication element. In this way, the embodiment can miniaturize the antenna device.

[0164] The features, structures, effects, etc. described in the above embodiments are included in at least one embodiment of the present invention and are not necessarily limited to only one embodiment. Furthermore, the features, structures, effects, etc. exemplified in each embodiment can be combined or modified in other embodiments by a person having ordinary skill in the art to which the embodiment belongs. Therefore, the contents related to such combinations and modifications should be interpreted as being included in the scope of the embodiment.

[0165] In addition, the above description has focused on the embodiments, but these are merely illustrative and do not limit the present invention. A person skilled in the art to which the present invention pertains will understand that various modifications and applications not exemplified above are possible within the scope of the essential characteristics of the present embodiments. For example, each component specifically illustrated in the embodiments can be modified and implemented. Differences related to such modifications and applications should be interpreted as being included in the scope of the present invention as defined in the appended claims.

Claims

1. An insulating layer; a circuit pattern layer disposed on the insulating layer; the circuit pattern layer includes an antenna pattern for transmitting and receiving an antenna signal; the antenna pattern includes an upper surface and a lower surface opposite the upper surface; the width of the upper surface is different from the width of the lower surface; A circuit board, wherein a width of one of the upper surface and the lower surface is 95% or more of a width of the other surface.

2. The circuit board according to claim 1 , wherein a width of the upper surface of the antenna pattern is smaller than a width of a lower surface of the antenna pattern.

3. 3. The circuit board according to claim 2, wherein the antenna pattern has a 10-point average surface roughness Rz in the range of 0.2 μm to 0.5 μm.

4. 3. The circuit board according to claim 2, wherein a difference between a width of the upper surface and a width of the lower surface of the antenna pattern satisfies a range of 0.5 μm to 1.2 μm.

5. the antenna pattern includes a side surface connecting the upper surface and the lower surface, 2. The circuit board according to claim 1, wherein a horizontal distance between one end of the upper surface of the antenna pattern connected to a side surface of the antenna pattern and one end of the lower surface of the antenna pattern satisfies a range of 0.25 μm to 0.6 μm.

6. The circuit board according to claim 5 , wherein a side surface of the antenna pattern includes a curved surface.

7. the side includes a first side and a second side opposite the first side; The first side is recessed toward the second side, The circuit board of claim 6 , wherein the second side is recessed toward the first side.

8. The etching factor of the antenna pattern is 40 or more; 2. The circuit board of claim 1, wherein the etching factor is determined by the following formula: Etching factor = antenna pattern thickness / (width of bottom surface of antenna pattern - width of top surface of antenna pattern)

9. The antenna pattern is a first metal layer disposed on the insulating layer; 2. The circuit board of claim 1, further comprising: a second metal layer disposed on the first metal layer, the second metal layer comprising a different metal than the first metal layer.

10. the first metal layer comprises nickel and chromium; The circuit board of claim 9 , wherein the second metal layer comprises copper.

11. The insulating layer is divided into a first region and a second region in a horizontal direction, The antenna pattern is a first antenna pattern disposed in the first region of the insulating layer; a second antenna pattern disposed in the second region of the insulating layer; the number of layers in the first region of the insulating layer is greater than the number of layers in the second region of the insulating layer; The circuit board according to claim 1 , wherein the second region of the insulating layer is bent with respect to the first region of the insulating layer.

12. the first region of the insulating layer comprises the same insulating material as the second region of the insulating layer; The circuit board of claim 11 , wherein the insulating material comprises a liquid crystal polymer (LCP).

13. an insulating layer including a first region and a second region bendable from the first region; a first antenna pattern disposed in the first region of the insulating layer; a second antenna pattern disposed in the second region of the insulating layer; a first pad disposed in the first region of the insulating layer; a second pad disposed in the first region of the insulating layer; a first connection portion disposed on the first pad; a second connection portion disposed on the second pad; a communication element mounted on the first connection portion and coupled to the first and second antenna patterns; a power supply element mounted on the second connection portion and coupled to the first and second antenna patterns; At least one of the first and second antenna patterns includes an upper surface and a lower surface opposite to the upper surface; the width of the upper surface is different from the width of the lower surface; an antenna device, wherein a width of one of the upper surface and the lower surface is 95% or more of a width of the other of the upper surface and the lower surface;

14. The width of the upper surface is smaller than the width of the lower surface.

14. An antenna device according to claim 13.

15. 15. The antenna device according to claim 14, wherein a difference between a width of said upper surface and a width of said lower surface satisfies a range of 0.5 μm to 1.2 μm.

16. At least one of the first and second antenna patterns includes a side surface connecting the upper surface and the lower surface, 13. The antenna device according to claim 12, wherein a horizontal distance between one end of the upper surface and one end of the lower surface which are respectively connected to one end and the other end of the side surface satisfies a range of 0.25 μm to 0.6 μm.

17. At least one of the first and second antenna patterns a first metal layer disposed on the insulating layer and comprising nickel and chromium; and a second metal layer disposed on the first metal layer, the second metal layer comprising copper.

18. the first region of the insulating layer comprises the same insulating material as the second region of the insulating layer; The antenna device of claim 13 , wherein the insulating material comprises a liquid crystal polymer (LCP).

19. The antenna device according to claim 13, wherein the ten-point average surface roughness Rz of each of the first and second antenna patterns is in the range of 0.2 μm to 0.5 μm.

20. a body including a front surface, a back surface opposite the front surface, and a plurality of side surfaces between the front surface and the back surface; A display unit disposed on a front surface of the main body; and the antenna device according to claim 13, which is disposed on at least two of the rear surface and the plurality of side surfaces of the main body, the first region of the insulating layer of the antenna device is disposed on a rear surface of the body; the second region of the insulating layer of the antenna device is disposed on a first side surface of the main body that is connected to a rear surface of the main body, among a plurality of side surfaces of the main body; the first antenna pattern emits an antenna signal toward a rear surface of the main body; The second antenna pattern radiates an antenna signal toward the first side of the body.

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