Antenna board

Abstract

The antenna substrate of the embodiment includes a substrate, an antenna pattern layer on the substrate, a first insulating layer containing a resin and an inorganic filler on the substrate and the antenna pattern layer, and a second insulating layer containing a resin and an inorganic filler on the first insulating layer, wherein the second insulating layer has a greater dielectric constant and thickness than the first insulating layer.

Description

Technical Field

[0001] The embodiments relate to an antenna substrate.

Background Art

[0002] Recently, efforts have been made to develop an improved 5G (5th generation) communication system or a pre-5G communication system to meet the demand for wireless data traffic.

[0003] To achieve a high data transmission rate, the 5G communication system uses a millimeter wave (mmWave) band (sub 6G (6 GHz), 28G 28 GHz, 38G 38 GHz or higher frequencies). Such a high frequency band is called mmWave due to the wavelength length.

[0004] To mitigate the path loss of radio waves and increase the radio wave transmission distance in the millimeter wave band, integrated technologies such as beamforming, massive MIMO (massive multiple-input multiple-output), and array antenna have been developed in the 5G communication system.

[0005] Considering that the wavelength consists of hundreds of active antennas in such a frequency band, the antenna system becomes relatively large.

[0006] This means that a large number of substrates constituting the active antenna system, namely, the antenna substrate, the antenna power supply substrate, the transceiver substrate, and the baseband substrate, must be integrated as one compact unit.

[0007] On the other hand, recently, a technology has been developed that uses a dielectric layer with a high dielectric constant to form the resonant frequency of an antenna. Conventionally, the resonant frequency is formed using an EMC (Epoxy Molding Compound) or a prepreg with a high dielectric constant.

[0008] However, conventional structures utilizing EMC (Electromagnetic Computing) employ a molding process to form a dielectric layer (EMC layer) for resonant frequency formation, which leads to the problem of increased overall antenna module thickness. For example, since the EMC layer is formed by the molding process, it has a thickness of 300 μm or more, which increases the overall thickness of the antenna module. Furthermore, when forming the EMC layer using a molding process, due to the characteristics of the manufacturing process, there is a problem of the molding resin flowing out of the mold, resulting in a decrease in yield.

[0009] Furthermore, in structures utilizing high-dielectric-constant prepregs, at least one of the multiple insulating layers is formed from a high-dielectric-constant prepreg during the substrate lamination process. However, when at least one of the multiple insulating layers is formed from a high-dielectric-constant prepreg during the substrate lamination process, a problem arises where substrate twisting occurs due to the difference in dielectric constant between the high-dielectric-constant prepreg and the other insulating layers. Additionally, when forming an antenna substrate containing a high-dielectric-constant prepreg, static electricity and harmful out-gas are generated, leading to void and reliability problems and a decrease in yield. [Overview of the project] [Problems that the invention aims to solve]

[0010] In this embodiment, we aim to provide an antenna substrate with a novel structure.

[0011] Furthermore, in this embodiment, we aim to provide an antenna substrate that allows for slimming down the substrate and shifting the resonant frequency.

[0012] The technical problems that the embodiments attempt to solve are not limited to those mentioned above, and any other technical problems not mentioned will be clearly understood by those with ordinary skill in the art to which the embodiments belong from the following description. [Means for solving the problem]

[0013] The antenna substrate according to the embodiment includes a substrate, a conductive antenna pattern layer on the substrate, a first insulating layer containing resin and inorganic filler on the substrate and the conductive antenna pattern layer, and a second insulating layer containing resin and inorganic filler on the first insulating layer, wherein the dielectric constant and thickness of the second insulating layer are greater than those of the first insulating layer.

[0014] Furthermore, the conductive antenna pattern layer includes a plurality of antenna patterns spaced apart from each other, and the first insulating layer covers all the spaces between the plurality of antenna patterns.

[0015] Furthermore, the dielectric constant of the second insulating layer is 3 to 6 times that of the first insulating layer.

[0016] Furthermore, the second insulating layer is 1.5 to 5 times the thickness of the first insulating layer.

[0017] Furthermore, the thickness of the conductive antenna pattern layer is thinner than the thickness of the first insulating layer and the second insulating layer.

[0018] Furthermore, the materials of the first insulating layer and the second insulating layer are different from each other.

[0019] Furthermore, the conductive antenna pattern layer is a dual resonant antenna pattern that resonates in different frequency bands.

[0020] Furthermore, the conductive antenna pattern layer resonates in a first frequency band of 24.03 GHz to 25.81 GHz and a second frequency band of 27.07 GHz to 28.80 GHz, respectively.

[0021] Also, the thickness of the second insulating layer is 25 μm to 65 μm.

[0022] Also, the thickness of the first insulating layer is 10 μm to 20 μm.

[0023] Also, the second insulating layer contains at least one selected from the group consisting of TiO2, Al2O3, BaTiO3, and CaTiO3.

[0024] Also, the first insulating layer is SiO2.

[0025] Also, the second insulating layer is formed in a certain pattern at regular intervals on the conductive antenna pattern layer.

[0026] Also, the second insulating layer has a dielectric constant Dk of 15 to 20.

[0027] Also, the first insulating layer has a dielectric constant Dk of 3 to 5.

[0028] Also, the thickness of the first insulating layer is the thickness between the conductive antenna pattern layers.

[0029] Also, the thicknesses of the first insulating layer and the second insulating layer are the thicknesses of the thickest parts.

Advantages of the Invention

[0030] In this embodiment, a high dielectric constant insulating layer (e.g., a solder resist layer) is placed on top of the conductive antenna pattern layer, thereby shifting the resonant frequency band of the conductive antenna pattern layer using the insulating layer. As a result, in this embodiment, by shifting the resonant frequency band using the insulating layer, the thickness of the antenna substrate can be drastically reduced compared to the comparative example using EMC, and the reliability problems caused by the molding process can be solved, thereby increasing the yield. In addition, in this embodiment, the reliability problems caused by out-gas generation can be solved compared to the comparative example using high dielectric prepreg, and the product cost can be reduced by eliminating the expensive high dielectric prepreg. [Brief explanation of the drawing]

[0031] [Figure 1] This is a drawing showing an antenna substrate according to the first embodiment. [Figure 2] This drawing shows a modified example of the antenna substrate of the first embodiment. [Figure 3] This diagram shows the resonant frequency characteristics of a conventional antenna substrate. [Figure 4] This figure shows the resonant frequency characteristics due to the change in height of the second insulating layer having the first dielectric constant according to the embodiment. [Figure 5] This figure shows the resonant frequency characteristics due to the change in height of the second insulating layer having a second dielectric constant according to the embodiment. [Figure 6] This figure shows the resonant frequency characteristics due to the change in height of the second insulating layer having a third dielectric constant according to the embodiment. [Figure 7] This is a drawing showing an antenna substrate according to the second embodiment. [Figure 8] This is a drawing showing an antenna substrate according to the third embodiment. [Modes for carrying out the invention]

[0032] Terms that are commonly used, like defined terms, can be interpreted by considering their meaning within the context of the technology they relate to.

[0033] Furthermore, the terms used in the embodiments of the present invention are for illustrative purposes only and are not intended to limit the invention. In this specification, the singular form may also include the plural form unless otherwise specified in the text, and when it is written as "at least one (or more) of A and B, C", it may include one or more of all possible combinations of A, B, and C.

[0034] Furthermore, in describing the components of the embodiments of the present invention, terms such as first, second, A, B, (a), (b), etc., may be used. Such terms are used to distinguish a component from other components, and the terms do not limit the nature or order of the component. When it is stated that a component is "linked," "joined," or "connected" to another component, this may include not only cases where the component is directly linked, joined, or connected to the other component, but also cases where it is "linked," "joined," or "connected" by yet another component between that component and the other component.

[0035] Furthermore, when it is stated that a component is formed or positioned "above or below" another component, "above or below" includes not only cases where two components are in direct contact, but also cases where one or more other components are formed or positioned between the two components. Also, when expressed as "above or below," it can include not only the upward direction but also the downward direction, with respect to one component.

[0036] Referring to Figure 1, the antenna substrate includes a substrate 110, a conductive antenna pattern layer 120, a first insulating layer 130, and a second insulating layer 140.

[0037] The first insulating layer 130 and the second insulating layer 140 may, for example, be insulating layers. That is, the first insulating layer 130 and the second insulating layer 140 may be protective layers that are placed on the outermost surface of the substrate and thereby function to protect the conductive antenna pattern layer 120.

[0038] The substrate 110 may be provided for feeding and supporting the antenna substrate. The substrate 110 may be a printed circuit board (PCB). Such a substrate 110 has a flat structure. Such a substrate 110 may consist of a single layer, or it may be realized by laminating multiple layers. The substrate 110 may include a grounding layer (not shown) for grounding and a power supply section (not shown) for power supply.

[0039] A conductive antenna pattern layer 120 is formed on one surface of the substrate 110. The conductive antenna pattern layer 120 may be provided on the antenna substrate for signal transmission and reception. The conductive antenna pattern layer 120 can transmit and receive signals in a predetermined resonant frequency band. For example, the conductive antenna pattern layer 120 can transmit and receive electromagnetic waves by operating in the resonant frequency band. The conductive antenna pattern layer 120 can operate by being supplied with power from a power supply unit (not shown) of the substrate 110.

[0040] The conductive antenna pattern layer 120 can resonate in multiple resonant frequency bands. For example, the conductive antenna pattern layer 120 may be a dual resonant antenna that resonates in different resonant frequency bands. For instance, the conductive antenna pattern layer 120 may be a dual resonant antenna that resonates in a first frequency band of 24.03 GHz to 25.81 GHz and a second frequency band of 27.07 GHz to 28.80 GHz, respectively.

[0041] On the other hand, although not shown in the drawings, a conductive antenna pattern layer 120 is also formed within the substrate 110. That is, the conductive antenna pattern layer 120 may be formed in a multilayer structure within the substrate 110. The conductive antenna pattern layer 120 shown in the drawings is a pattern arranged on the outermost surface of the substrate 110. That is, the conductive antenna pattern layer 120 can have a multilayer structure, or, conversely, a single-layer structure. The number of layers of the conductive antenna pattern layer 120 is determined based on the resonant frequency band. In this embodiment, we will mainly describe the conductive antenna pattern layer 120 arranged on the outermost surface of the substrate 110. The conductive antenna pattern layer 120 is formed on one surface of the substrate 110 with a thickness of 10 μm to 15 μm. For example, the conductive antenna pattern layer 120 is formed on one surface of the substrate 110 with a thickness of 12 μm.

[0042] Multiple insulating layers (for example, solder resist layers) are formed on the substrate 110.

[0043] Specifically, the plurality of insulating layers may include a first insulating layer 130 formed on the substrate 110 and the conductive antenna pattern layer 120, and a second insulating layer 140 disposed on the first insulating layer 130. The first insulating layer 130 can completely cover the space between the conductive antenna pattern layer 120 formed on one surface of the substrate 110. For example, the conductive antenna pattern layer 120 includes a plurality of antenna patterns spaced apart from each other. The first insulating layer 130 is formed to completely cover the space between the plurality of antenna patterns spaced apart from each other. The second insulating layer 140 is disposed on the first insulating layer 130 or the conductive antenna pattern layer 120 at regular intervals. That is, the first insulating layer 130 is formed in a region that overlaps perpendicularly with the conductive antenna pattern layer 120. In this case, the conductive antenna pattern layer 120 includes a plurality of antenna patterns spaced apart from each other on the substrate 110. Therefore, the second insulating layer 140 is formed on the first insulating layer 130 or the conductive antenna pattern layer 120 at regular intervals in a regular pattern, corresponding to the conductive antenna pattern layer 120.

[0044] The first insulating layer 130 and the second insulating layer 140 may have different areas. For example, the area of ​​the first insulating layer 130 may be larger than the area of ​​the second insulating layer 140. This means that the second insulating layer 140 may not be formed on at least a portion of the upper surface of the first insulating layer 130. For example, the second insulating layer 140 may be selectively placed only on the upper surface of the first insulating layer 130 in a region that overlaps perpendicularly with the conductive antenna pattern layer 120.

[0045] The width W1 of the second insulating layer 140 may be greater than the width W2 of the conductive antenna pattern layer 120. This allows the second insulating layer 140 to include a first portion that overlaps the conductive antenna pattern layer 120 in the vertical direction and a second portion other than the first portion that does not overlap the conductive antenna pattern layer 120. However, the embodiment is not limited thereto, and the second insulating layer 140 may have the same width as the conductive antenna pattern layer 120, while its entire area overlaps the conductive antenna pattern layer 120 in the vertical direction.

[0046] The first insulating layer 130 is formed on the substrate 110 with a first thickness T1. The second insulating layer 140 is formed on the first insulating layer 130 with a second thickness T2 that is greater than the first thickness T1. For example, the second thickness T2 of the second insulating layer 140 may be 1.5 to 5 times the first thickness T1 of the first insulating layer 130. If the second thickness T2 is less than 1.5 times the first thickness T1, the frequency shift effect for forming the resonant frequency band will be small. If the second thickness T2 is less than 1.5 times the first thickness T1, a problem may arise in which the resonant frequency band of the conductive antenna pattern layer 120 cannot be shifted to the target frequency band. If the second thickness T2 is greater than 5 times the first thickness T1, the overall thickness of the antenna substrate will increase due to the increase in the thickness of the second insulating layer 140. If the second thickness T2 is less than five times the first thickness T1, the resonant frequency band of the conductive antenna pattern layer 120 may fall outside the desired target frequency band.

[0047] For this purpose, the first thickness T1 of the first insulating layer 130 can be 10 μm to 20 μm. Also, the second thickness T2 of the second insulating layer 140 can be 25 μm to 65 μm. Here, as described above, the conductive antenna pattern layer 120 can have a thickness of 10 μm to 15 μm. As a result, the first thickness T1 of the first insulating layer 130 is greater than the thickness of the conductive antenna pattern layer 120. Here, the first thickness T1 of the first insulating layer 130 may be the thickness between the conductive antenna pattern layer 120. Specifically, the first thickness T1 of the first insulating layer 130 may be the thickness from the top surface of the substrate 110 to the top surface of the first insulating layer 130. More specifically, the first thickness T1 of the first insulating layer 130 may be the thickness of the thickest part of the entire area of ​​the first insulating layer 130. Similarly, the second thickness T2 of the second insulating layer 140 may be the thickness of the thickest part of the entire area of ​​the second insulating layer 140.

[0048] Furthermore, if the first thickness T1 of the first insulating layer 130 is greater than the thickness of the conductive antenna pattern layer 120, the first insulating layer 130 is also placed on top of the conductive antenna pattern layer 120. For example, the first insulating layer 130 is also formed between the second insulating layer 140 and the conductive antenna pattern layer 120. Alternatively, as shown in Figure 2, the first thickness T1 of the first insulating layer 130 may be the same as the thickness of the conductive antenna pattern layer 120. In such a case, the first insulating layer 130 does not need to be formed between the conductive antenna pattern layer 120 and the second insulating layer 140.

[0049] That is, the first insulating layer 130 in the embodiment may be selectively formed between the conductive antenna pattern layer 120 and the second insulating layer 140. The third thickness T3 of the first insulating layer 130 between the conductive antenna pattern layer 120 and the second insulating layer 140 can be 0 μm to 3 μm. When the third thickness T3 is greater than 3 μm, the frequency shift effect due to the second insulating layer 140 becomes negligible. Also, when the third thickness T3 is greater than 3 μm, the overall thickness of the antenna substrate increases due to the increase in the thickness of the first insulating layer 130.

[0050] On the other hand, the thickness of the first insulating layer 130 can mean the thickness from the lower surface of the conductive antenna pattern layer 120 to the upper surface of the first insulating layer 130. For example, the thickness of the first insulating layer 130 may include the thickness of the conductive antenna pattern layer 120 and the first insulating layer 130 located on the conductive antenna pattern layer 120. The portion of the first insulating layer 130 formed between the conductive antenna pattern layer 120 may be located lower than the conductive antenna pattern layer 120. For example, the first insulating layer 130 may include a first region located on the conductive antenna pattern layer 120 and a second region located on the substrate 110 between the conductive antenna pattern layer 120. The thickness of the first insulating layer 130 may be the sum of the thickness of the conductive antenna pattern layer 120 and the thickness of the first region of the first insulating layer 130. The thickness of the second region of the first insulating layer 130 may be thinner than the thickness of the conductive antenna pattern layer 120.

[0051] On the other hand, the first insulating layer 130 and the second insulating layer 140 may have different dielectric constants. Specifically, the dielectric constant of the second insulating layer 140 may be greater than that of the first insulating layer 130. More specifically, the dielectric constant of the second insulating layer 140 may be 3 to 6 times that of the first insulating layer 130. If the dielectric constant of the second insulating layer 140 is less than 3 times or more than 5 times that of the first insulating layer 130, the resonant frequency band of the conductive antenna pattern layer 120 will fall outside the target frequency band, resulting in a decrease in antenna performance. For this reason, the dielectric constant Dk of the first insulating layer 130 may be 3 to 5. Also, the dielectric constant Dk of the second insulating layer 140 may be 15 to 20.

[0052] For this reason, the first insulating layer 130 and the second insulating layer 140 may contain materials that are different from each other.

[0053] That is, the first insulating layer 130 and the second insulating layer 140 can each contain a resin and an inorganic filler, respectively.

[0054] In this case, the inorganic filler constituting the first insulating layer 130 may be different from the inorganic filler constituting the second insulating layer 140. For example, the dielectric constant of the filler contained in the first insulating layer 130 may be smaller than the dielectric constant of the filler contained in the second insulating layer 140.

[0055] The first insulating layer 130 may contain SiO2.

[0056] The second insulating layer 140 includes at least one of the group composed of TiO2, Al2O3, BaTiO3, and CaTiO3. That is, the dielectric constants of TiO2, Al2O3, BaTiO3, and CaTiO3 are greater than the dielectric constant of SiO2, and as a result, the dielectric constant of the second insulating layer 140 is greater than that of the first insulating layer 130. For example, the second insulating layer 140 may include an inorganic material containing Ti.

[0057] The first insulating layer 130 may be filled with SiO2 in an amount of 20% to 70% by weight within the resin.

[0058] The second insulating layer 140 contains at least one of TiO2, Al2O3, BaTiO3, and CaTiO3 in the resin, and may further contain SiO2.

[0059] That is, the second insulating layer 140 may contain only at least one selected from TiO2, Al2O3, BaTiO3, and CaTiO3. Alternatively, the second insulating layer 140 may further contain SiO2 in addition to at least one selected from TiO2, Al2O3, BaTiO3, and CaTiO3.

[0060] If the second insulating layer 140 contains only one selected from the group consisting of TiO2, Al2O3, BaTiO3, and CaTiO3, then it contains at least one of these. At least one of TiO2, Al2O3, BaTiO3, and CaTiO3 may be filled into the resin in an amount of 15% to 45% by weight.

[0061] In contrast to this, when the second insulating layer 140 contains at least one of TiO2, Al2O3, BaTiO3, and CaTiO3, and all of SiO2, these combinations are present in the resin at a concentration of 20% to 70% by weight, of which at least one of TiO2, Al2O3, BaTiO3, and CaTiO3 can account for 5% to 45% by weight.

[0062] Furthermore, the average size of the inorganic filler in the first insulating layer 130 may differ from the average size of the inorganic filler in the second insulating layer 140. For example, the average size of the inorganic filler in the first insulating layer 130 may be larger than the average size of the inorganic filler in the second insulating layer 140. For example, the average size of the inorganic filler in the first insulating layer 130 may be 4 μm or less. For example, the average size of the inorganic filler in the second insulating layer 140 may be 3 μm or less.

[0063] As described above, in the embodiment, the second insulating layer 140 contains a high dielectric constant filler, which includes at least one of TiO2, Al2O3, BaTiO3, and CaTiO3, so that the dielectric constant of the second insulating layer 140 is greater than that of the first insulating layer 130. The second insulating layer 140 having a dielectric constant of 15 to 20 as described above allows the resonant frequency band formed by the conductive antenna pattern layer 120 to be shifted to a desired target frequency band.

[0064] The frequency shift effect in the antenna substrate including the second insulating layer 140 according to the embodiment will be explained below.

[0065] Figure 3 shows the resonant frequency characteristics of a conventional antenna substrate, Figure 4 shows the resonant frequency characteristics due to height changes of the second insulating layer having a first dielectric constant according to the embodiment, Figure 5 shows the resonant frequency characteristics due to height changes of the second insulating layer having a second dielectric constant according to the embodiment, and Figure 6 shows the resonant frequency characteristics due to height changes of the second insulating layer having a third dielectric constant according to the embodiment.

[0066] Figure 3 shows the resonant frequency characteristics of a conventional antenna substrate with EMC placed on top of the conductive antenna pattern layer. Conventionally, a dielectric layer using EMC was formed on top of the conductive antenna pattern layer to shift the resonant frequency band. In this case, the dielectric layer using EMC had a dielectric constant Dk of about 8 and a thickness of about 300 μm. At this time, using the S-parameter (scattering parameter) of -10 dB as the reference, the resonant frequency band of the conductive antenna pattern layer appeared to be 23.60 GHz to 24.85 GHz, and it was confirmed that the peak frequency appeared to be 24.15 GHz. However, when using such EMC, there are problems with the increase in thickness and reliability problems that arise due to the molding process.

[0067] In contrast, in this embodiment, a second insulating layer 140 with a high dielectric constant having a thickness of 80 μm or less can be used to ensure the same performance as a dielectric layer using conventional EMC.

[0068] In the examples, as shown in Figure 4, the height of the second insulating layer with a dielectric constant Dk of 10 was varied to 15 μm, 40 μm, and 65 μm, and the resulting changes in frequency characteristics were observed. In the examples, as shown in Figure 5, the height of the second insulating layer with a dielectric constant Dk of 15 was varied to 15 μm, 40 μm, and 65 μm, and the resulting changes in frequency characteristics were observed. In the examples, as shown in Figure 6, the height of the second insulating layer with a dielectric constant Dk of 20 was varied to 15 μm, 40 μm, and 65 μm, and the resulting changes in frequency characteristics were observed.

[0069] Table 1 shows the frequency characteristics change depending on the dielectric constant and height of the second insulating layer 140. [Table 1]

[0070] In summary, using Table 1 above as a reference, when the dielectric constant of the second insulating layer 140 is 10, it was confirmed that the peak frequency is downshifted by 150 MHz for every 25 μm increase in its thickness, and the edge portion of the frequency band is downshifted by approximately 180 to 200 MHz.

[0071] Furthermore, when the dielectric constant of the second insulating layer 140 is 15, it was confirmed that the peak frequency is downshifted by 250 MHz for every 25 μm increase in its thickness, and that the edge portion of the frequency band is downshifted by approximately 200 to 300 MHz.

[0072] Furthermore, when the dielectric constant of the second insulating layer 140 is 20, it was confirmed that the peak frequency is downshifted by 250 to 350 MHz for every 25 μm increase in its thickness, and that the edge portion of the frequency band is downshifted by approximately 300 to 400 MHz.

[0073] Furthermore, using thickness as a reference, we confirmed that when the thickness of the second insulating layer 140 is 15 μm, the peak frequency is downshifted by 50 MHz for every 5 MHz increase in its dielectric constant, and we were able to confirm that the edge portion of the frequency band is downshifted by approximately 60-80 MHz.

[0074] Furthermore, when the thickness of the second insulating layer 140 is 40 μm, we confirmed that the peak frequency is downshifted by 150 MHz for every 5 MHz increase in its dielectric constant, and that the edge portion of the frequency band is downshifted by approximately 170-190 MHz.

[0075] Furthermore, when the thickness of the second insulating layer 140 is 65 μm, it was confirmed that the peak frequency is downshifted by 250 to 350 MHz for every 5 μm increase in its dielectric constant, and that the edge portion of the frequency band is downshifted by approximately 300 to 400 MHz.

[0076] As a result, in the examples, it was confirmed that when the dielectric constant of the second insulating layer 140 is 15 to 20 and its thickness is 25 to 60 μm, it is effective in shifting the resonant frequency band of the conductive antenna pattern layer 120, and it was confirmed that it is possible to ensure the same performance as conventional EMC with a thickness of 300 μm or more.

[0077] The following will describe additional examples.

[0078] Figure 7 is a diagram showing an antenna substrate according to the second embodiment.

[0079] Referring to Figure 7, the substrate 210, conductive antenna pattern layer 220, and insulating layer 240 can be included. The substrate 210 and conductive antenna pattern layer 220 have substantially the same structure and configuration as the antenna substrate in the first embodiment shown in Figure 1, so a detailed explanation thereof will be omitted.

[0080] The antenna substrate in the second embodiment includes an insulating layer 240. The insulating layer 240 is disposed on the substrate 210 and the conductive antenna pattern layer 220. That is, in the antenna substrate of the first embodiment, a first insulating layer 130 and a second insulating layer 140 having different dielectric constants are disposed on the substrate and the antenna pattern, respectively. In contrast, in the antenna substrate of the second embodiment, a single insulating layer is disposed on the substrate and the antenna pattern.

[0081] For this reason, the insulating layer 240 can correspond to the second insulating layer 140 in Figure 1. That is, the dielectric constant of the insulating layer 240 may be 15 to 20.

[0082] In this case, the insulating layer 240 may have a first thickness T1. The first thickness T1 may refer to the thickness of the thickest region of the entire insulating layer 240. For example, the first thickness T1 may be the thickness of the insulating layer 240 on the substrate. The first thickness T1 of the insulating layer 240 may be 40 μm to 80 μm. As a result, the insulating layer 240 in the embodiment is positioned on the conductive antenna pattern layer 220 at a certain height. For example, the thickness of the insulating layer 240 on the conductive antenna pattern layer 220 may be 28 μm to 68 μm. That is, if the thickness of the conductive antenna pattern layer 220 is 12 μm, the thickness of the insulating layer 240 on the conductive antenna pattern layer 220 may be 28 μm to 68 μm.

[0083] On the other hand, the thickness of the insulating layer 240 can mean the thickness from the lower surface of the conductive antenna pattern layer 220 to the upper surface of the insulating layer 240. For example, the thickness of the insulating layer 240 may include the thickness of the conductive antenna pattern layer 220 and the insulating layer 240 located on the conductive antenna pattern layer 220. The portion of the insulating layer 240 formed between the conductive antenna pattern layers 220 may be located lower than the conductive antenna pattern layers 220. For example, the insulating layer 240 may include a first region located on the conductive antenna pattern layer 220 and a second region located on the substrate 210 between the conductive antenna pattern layers 220. The thickness of the insulating layer 240 may be the sum of the thickness of the conductive antenna pattern layer 220 and the thickness of the first region of the insulating layer 220. Furthermore, the thickness of the second region of the insulating layer 240 may be thinner than the thickness of the conductive antenna pattern layer 220.

[0084] Figure 8 is a diagram showing an antenna substrate according to the third embodiment.

[0085] Referring to Figure 8, the substrate 310, conductive antenna pattern layer 320, first insulating layer 330, and second insulating layer 340 can be included. The substrate 310 and conductive antenna pattern layer 320 have substantially the same structure and configuration as the antenna substrate in the first embodiment shown in Figure 1, so a detailed explanation thereof will be omitted.

[0086] The antenna substrate in the third embodiment includes a first insulating layer 330 and a second insulating layer 340. In this case, the material properties of the first insulating layer 330 are the same as those of the first insulating layer 130 in the first embodiment. Also, the material properties of the second insulating layer 340 are the same as those of the second insulating layer 140 in the first embodiment. However, in the first embodiment, the first insulating layer was formed on the substrate and the conductive antenna pattern layer, and the second insulating layer was formed on top of that. As a result, the upper surface of the first insulating layer in the first embodiment was located lower than the upper surface of the second insulating layer.

[0087] In contrast to the above, in the third embodiment, the first insulating layer 330 is formed on the substrate 310, and the second insulating layer 340 is formed on the conductive antenna pattern layer 320. That is, the first insulating layer 330 is formed on the substrate 310 with an opening (not shown) that exposes the surface of the conductive antenna pattern layer 320. The second insulating layer 340 is formed on the conductive antenna pattern layer 320 exposed through the opening in the first insulating layer 330. As a result, the lower surface of the second insulating layer 340 can directly contact the upper surface of the conductive antenna pattern layer 320. The width of the second insulating layer 340 may also be the same as the width of the conductive antenna pattern layer 320. Furthermore, the upper surface of the second insulating layer 340 can be located on the same plane as the upper surface of the first insulating layer 330. Here, the meaning of "same" is not bound by a strict meaning, but is interpreted to include a range in which similar functions can be expected.

[0088] The first insulating layer 330 can have a first thickness T1 of 40 μm to 80 μm. The second insulating layer 340 can have a second thickness T2 of 28 μm to 68 μm. That is, the conductive antenna pattern layer 320 can have a thickness of 12 μm, which allows the second insulating layer 340 to have a second thickness T2 of 28 μm to 68 μm.

[0089] On the other hand, the materials constituting the first insulating layer 330, the materials constituting the second insulating layer 340, and the relationship between the dielectric constants of the first insulating layer 330 and the second insulating layer 340 have already been explained in the first embodiment, so we will omit further explanation here.

[0090] In this embodiment, a high dielectric constant insulating layer is placed on top of a conductive antenna pattern layer, thereby shifting the resonant frequency band of the conductive antenna pattern layer using the insulating layer. As a result, in this embodiment, by shifting the resonant frequency band using the insulating layer, the thickness of the antenna substrate can be drastically reduced compared to the comparative example using EMC, and reliability problems caused by the molding process can be solved, thereby increasing the yield. In addition, in this embodiment, reliability problems caused by out-gas generation can be solved compared to the comparative example using a high dielectric prepreg, and product costs can be reduced by eliminating the expensive high dielectric prepreg.

[0091] The features, structures, and effects described in the above embodiments are included in at least one embodiment of the present invention, and are not necessarily limited to a single embodiment. Furthermore, the features, structures, and effects exemplified in each embodiment can be combined or modified for implementation in other embodiments by a person with ordinary skill in the art to which the embodiment belongs. Therefore, such combinations and modifications should be interpreted as being included within the scope of the present invention.

[0092] While the above description has focused on embodiments, these are merely illustrative and do not limit the present invention. A person with ordinary skill in the art to which the present invention belongs can make various modifications and applications not exemplified above, without departing from the essential characteristics of these embodiments. For example, each component specifically presented in the embodiments can be modified and implemented. Such differences resulting from modifications and applications should be interpreted as being within the scope of the present invention as defined in the appended claims.

Claims

1. circuit board and A first solder resist layer, which is placed on the substrate and has openings, A conductive pattern layer is placed on the substrate and positioned within the opening of the first solder resist layer, The conductive pattern layer includes a second solder resist layer disposed on top of the conductive pattern layer, The first solder resist layer contains a material different from the material of the second solder resist layer. The thickness of the second solder resist layer is greater than the thickness of the first solder resist layer. The conductive pattern layer includes a plurality of conductive patterns spaced apart from each other along the horizontal direction. The second solder resist layer includes a plurality of insulating patterns that are spaced apart from each other and are arranged in regions on the upper surface of the first solder resist layer that overlap perpendicularly with the plurality of conductive patterns. An antenna substrate in which the horizontal width of each of the plurality of insulating patterns is greater than the horizontal width of each of the plurality of conductive patterns.

2. The antenna substrate according to claim 1, wherein the dielectric constant of the second solder resist layer is greater than the dielectric constant of the first solder resist layer.

3. The antenna substrate according to claim 2, wherein the dielectric constant of the second solder resist layer is 3 to 6 times that of the first solder resist layer.

4. The antenna substrate according to any one of claims 1 to 3, wherein the thickness of the second solder resist layer is 1.5 to 5 times the thickness of the first solder resist layer.

5. The antenna substrate according to any one of claims 1 to 4, wherein the thickness of the conductive pattern layer is thinner than the thickness of the second solder resist layer.

6. The antenna substrate according to any one of claims 1 to 5, wherein the conductive pattern layer is a dual resonant antenna pattern layer that resonates in different frequency bands.

7. The antenna substrate according to claim 6, wherein the conductive pattern layer resonates in a first frequency band of 24.03 GHz to 25.81 GHz and a second frequency band of 27.07 GHz to 28.80 GHz, respectively.

8. The antenna substrate according to any one of claims 1 to 3, wherein the thickness of the second solder resist layer is 25 μm to 65 μm.

9. The antenna substrate according to claim 8, wherein the thickness of the first solder resist layer is 10 μm to 20 μm.

10. The second solder resist layer is TiO ２ Al ２ O ３ , BaTiO ３ and CaTiO ３ An antenna substrate according to any one of claims 1 to 9, comprising at least one of the group composed of the following.

11. The second solder resist layer is made of SiO ２ The antenna substrate according to claim 10, further comprising:

12. The first solder resist layer is made of SiO ２ The antenna substrate according to claim 10.

13. The antenna substrate according to claim 3, wherein the dielectric constant of the first solder resist layer satisfies the range of 3 to 5.

14. The antenna substrate according to claim 3, wherein the dielectric constant of the second solder resist layer satisfies the range of 15 to 20.

15. The antenna substrate according to claim 1, wherein the thickness of the first solder resist layer is the same as the thickness of the conductive pattern layer.

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