Antenna substrate and antenna module comprising same

Abstract

The antenna substrate according to an embodiment comprises an insulation layer and a metal pattern disposed on the insulation layer, wherein a first gap is provided between the metal pattern and the insulation layer, and the height of the first gap is 0.1% to 10% of the thickness of the insulation layer.

Description

Antenna substrate and antenna module including the same

[0001] The embodiment relates to an antenna substrate and an antenna module including the same.

[0002] Recently, improved 5G (5th generation) communication systems or pre-5G communication systems are being developed to meet the demand for wireless data traffic.

[0003] To achieve high data rates, 5G communication systems use ultra-high frequency (mmWave) bands (frequencies of 6 GHz, 28 GHz, 38 GHz, or higher). These high frequency bands are called mmWave due to the length of their wavelengths.

[0004] To mitigate the path loss of radio waves in ultra-high frequency bands 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] Given that these frequency bands can consist of hundreds of active antennas at wavelengths, antenna systems can become relatively large.

[0006] This means that the multiple substrates that make up the active antenna system, namely the antenna substrate, the antenna feed substrate, the transceiver substrate, and the baseband substrate, must be integrated into one compact unit.

[0007] The above antenna substrate is formed into a multilayer structure. The antenna substrate is manufactured by bonding the multilayers using heat and pressure.

[0008] However, when the antenna substrate is exposed to a high temperature and / or high humidity environment, the adhesion of the multilayer may decrease. Accordingly, the characteristics and reliability of the antenna substrate may decrease.

[0009] Therefore, a new structure of an antenna substrate and an antenna module including the same that can solve the above problems are required.

[0010] As a prior art related to the above antenna substrate, Korean Patent Publication No. KR10-2021-0130192 is disclosed.

[0011] Embodiments provide an antenna substrate and antenna module having improved reliability and characteristics.

[0012] An antenna substrate according to an embodiment includes an insulating layer; a metal pattern disposed on the insulating layer, a first gap is provided between the metal pattern and the insulating layer, and the height of the first gap is 0.1% to 10% of the thickness of the insulating layer.

[0013] In addition, the insulating layer includes a first insulating layer; and a second insulating layer disposed on the first insulating layer, and the metal pattern includes a first metal pattern disposed on the second insulating layer, and a second metal pattern disposed between the first insulating layer and the second insulating layer, and the first gap is provided between the first insulating layer and the first metal pattern.

[0014] In addition, it further includes a second gap provided between the first insulating layer and the second insulating layer, and the height of the second gap is 0.1% to 10% of the thickness of the first insulating layer.

[0015] Additionally, the thickness of the first insulating layer is 25 µm to 150 µm.

[0016] Additionally, the height of the first gap or the second gap is 0.1 μm to 10 μm.

[0017] Additionally, the antenna substrate further includes a via electrode penetrating the second insulating layer in a vertical direction; and a bonding layer disposed between the via electrode and the second metal pattern.

[0018] Additionally, the bonding layer comprises a copper-tin alloy.

[0019] Additionally, at least one of the adhesive force between the first insulating layer and the second insulating layer and the adhesive force between the first insulating layer and the second metal pattern is 0.5 kgf to 1.5 kgf.

[0020] Meanwhile, an antenna substrate according to another embodiment includes an insulating structure including a lower insulating layer, an inner insulating layer disposed on the lower insulating layer, and an upper insulating layer disposed on the inner insulating layer; and a metal pattern including an upper metal pattern disposed on the upper insulating layer, and a first inner metal pattern disposed between the lower insulating layer and the inner insulating layer, and a second inner metal pattern disposed between the inner insulating layer and the upper insulating layer, wherein a gap is included in at least one of between the lower insulating layer and the first inner metal pattern, between the inner insulating layer and the second inner metal pattern, between the lower insulating layer and the inner insulating layer, and between the inner insulating layer and the upper insulating layer, and wherein a height of the gap is 0.1% to 10% of a thickness of any one of the lower insulating layer, the inner insulating layer, and the upper insulating layer.

[0021] Additionally, the inner insulating layer includes a first inner insulating layer and a second inner insulating layer disposed on the first inner insulating layer, and a thickness of the first inner insulating layer is different from a thickness of the second inner insulating layer.

[0022] Additionally, the thickness of the first inner insulating layer is different from the thicknesses of the lower insulating layer and the upper insulating layer, respectively.

[0023] Additionally, the thickness of the first inner insulating layer is greater than the thickness of each of the second inner insulating layer, the lower insulating layer, and the upper insulating layer.

[0024] In addition, the metal pattern further includes a third inner metal pattern disposed between the first inner insulating layer and the second inner insulating layer,

[0025] In addition, the gap includes a first gap provided between the lower insulating layer and the first inner metal pattern, a second gap arranged between the first inner insulating layer and the third inner metal pattern, and a third gap arranged between the second inner insulating layer and the upper insulating layer.

[0026] Additionally, the height of the second gap is different from the heights of the first and third gaps.

[0027] Additionally, the height of the second gap is greater than the heights of the first and third gaps.

[0028] Additionally, the deviation in height of the first gap to the third gap is 0.1% to 5% of the thickness of the insulating layer of any one of the lower insulating layer, the first inner insulating layer, the second inner insulating layer, and the upper insulating layer.

[0029] Additionally, the above deviation is 0.1㎛ to 5㎛.

[0030] An antenna substrate according to an embodiment includes a plurality of insulating layers. The insulating layers are bonded by a thermocompression process. The thermocompression process is performed at a set range of temperature, pressure, and time. In detail, the bonding temperature is similar to the melting point of the insulating layer. Accordingly, the adhesive strength of the insulating layer can be increased. Accordingly, the interlayer lifting of the antenna substrate is reduced, and the interlayer adhesion is improved. Accordingly, the signal loss of the antenna substrate according to the embodiment is reduced.

[0031] Additionally, even if the antenna substrate is exposed to a high temperature and high humidity environment for a long period of time, the adhesive strength of the insulating layer is maintained. Therefore, the operating characteristics of the antenna substrate do not change depending on the usage environment.

[0032] Accordingly, the driving characteristics and reliability of the antenna substrate according to the embodiment are improved.

[0033] Figure 1 is a top view of an antenna substrate according to an embodiment.

[0034] Figure 2 is a cross-sectional view taken along area AA' of Figure 1.

[0035] Figure 3 is an enlarged view of area B of Figure 2.

[0036] Figures 4 to 6 are drawings for explaining a manufacturing process of an antenna substrate according to an embodiment.

[0037] Figure 7 is an enlarged view of area C of Figure 6.

[0038] Figures 8 to 12 are scanning electron microscope (SEM) photographs of examples and comparative examples.

[0039] FIG. 13 is a cross-sectional view of an antenna package including an antenna substrate according to an embodiment.

[0040] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. However, the technical concept of the present invention is not limited to the described embodiments, but may be implemented in various different forms. Within the scope of the technical concept of the present invention, one or more of the components of the embodiments may be selectively combined or substituted for use.

[0041] In addition, terms (including technical and scientific terms) used in the embodiments of the present invention may be interpreted as having a meaning that can be generally understood by a person of ordinary skill in the technical field to which the present invention belongs, unless explicitly and specifically defined and described, and terms that are commonly used, such as terms defined in a dictionary, may be interpreted in consideration of the contextual meaning of the relevant technology.

[0042] In addition, the terms used in the embodiments of the present invention are for the purpose of describing the embodiments and are not intended to limit the present invention. In this specification, the singular may also include the plural unless specifically stated in the phrase, and when it is described as “and (and) at least one (or more) of B, C,” it may include one or more of all combinations that can be combined with A, B, and C.

[0043] Additionally, in describing components of embodiments of the present invention, terms such as first, second, A, B, (a), (b), etc. may be used. These terms are only intended to distinguish the components from other components, and are not intended to limit the nature, order, or sequence of the components.

[0044] And, when a component is described as being 'connected', 'coupled' or 'connected' to another component, it may include not only cases where the component is directly connected, coupled or connected to the other component, but also cases where the component is 'connected', 'coupled' or 'connected' by another component between the component and the other component.

[0045] Additionally, when it is described as being formed or disposed "above or below" each component, above or below includes not only cases where the two components are in direct contact with each other, but also cases where one or more other components are formed or disposed between the two components.

[0046] Additionally, when expressed as “upper or lower,” it can include the meaning of not only the upward direction but also the downward direction based on one component.

[0047]

[0048] Hereinafter, an antenna substrate and a smart IC card including the same according to an embodiment will be described with reference to the drawings.

[0049] The antenna substrate (1000) described below transmits a signal in the millimeter wavelength (mmWave) band. In detail, the antenna substrate (1000) transmits a signal in a high-frequency band. For example, the antenna substrate (1000) can transmit a high-frequency signal of 20 ㎓ or higher, 20 ㎓ to 45 ㎓, or 24 ㎓ to 41 ㎓.

[0050]

[0051] Referring to FIGS. 1 to 3, the antenna substrate (1000) includes an insulating layer (100), a first metal pattern (200), a second metal pattern (300), a via (V), and a third metal pattern (400).

[0052] The insulating layer (100) includes a plurality of insulating layers. Accordingly, the antenna substrate (100) is formed as a multilayer antenna substrate (1000). For example, the insulating layer (100) may include a first insulating layer (110), a second insulating layer (120), a third insulating layer (130), and a fourth insulating layer (140). However, the embodiment is not limited thereto. The insulating layer (100) may include five or more insulating layers. For example, the insulating layer (100) may include eight insulating layers.

[0053] Hereinafter, for convenience of explanation, the insulating layer is described as including four insulating layers.

[0054] The first insulating layer (110) is the lowermost insulating layer. In addition, the fourth insulating layer (140) is the uppermost insulating layer. The second insulating layer (120) and the third insulating layer (130) are disposed between the first insulating layer (110) and the fourth insulating layer (140). Specifically, the second insulating layer (120) is disposed on the first insulating layer (110). In addition, the third insulating layer (130) is disposed on the second insulating layer (120). In addition, the fourth insulating layer (140) is disposed on the third insulating layer (130).

[0055] The above insulating layer (100) comprises a resin material. For example, the insulating layer (100) may comprise a resin material whose physical properties change depending on temperature. For example, the insulating layer (100) may comprise a thermoplastic resin. Accordingly, the insulating layers (110, 120, 130, 140) may be thermo-compressed at a set temperature and pressure.

[0056] For example, the insulating layer (100) includes a liquid crystal polymer (LCP). The liquid crystal polymer is a material having both liquid and solid state properties. That is, the liquid crystal polymer has a regular crystal orientation in the liquid state, just like in the solid state.

[0057] The above insulating layer (100) has a thickness within a set range. For example, the thickness of the above insulating layer (100) may be 150 μm or less. More specifically, the thickness of the above insulating layer (100) may be 25 μm to 150 μm, 25 μm to 130 μm, or 75 μm to 110 μm.

[0058] If the thickness of the insulating layer (100) is less than 25 μm, a large number of layers may be required to manufacture the antenna substrate. Therefore, process efficiency is reduced. If the thickness of the insulating layer (100) exceeds 150 μm, the size of the via (V) may increase. As a result, the impedance of a high-frequency signal passing through the via (V) may become mismatched, resulting in discontinuous impedance. Therefore, the transmission loss of a signal having a set frequency range increases, thereby reducing the performance of the antenna substrate.

[0059] The thickness of any one of the plurality of insulating layers may be different from the thicknesses of the other insulating layers. For example, the thickness of the second insulating layer (120) or the third insulating layer (130) may be different from the thicknesses of the other insulating layers. For example, the thickness of the second insulating layer (120) may be greater than the thicknesses of the other insulating layers. That is, the second insulating layer (120) may be a core layer.

[0060] The above insulating layer (100) has a dielectric constant (Dk) within a set range. Specifically, the insulating layer (100) has a dielectric constant of 3.2 or less. Accordingly, the transmission loss of a high-frequency signal transmitted through the antenna substrate is reduced.

[0061]

[0062] The first metal pattern (200) is disposed on the uppermost insulating layer. Specifically, the first metal pattern (200) is disposed on the fourth insulating layer (140). The first metal pattern (200) may include at least one metal selected from the group consisting of gold (Au), silver (Ag), platinum (Pt), titanium (Ti), tin (Sn), copper (Cu), zinc (Zn), and alloys thereof. Preferably, the first metal pattern (200) includes copper (Cu).

[0063] The above first metal pattern (200) is a receiving section of the antenna substrate (1000). That is, the antenna substrate (1000) receives a signal in the frequency band range set by the first metal pattern (200).

[0064] The first metal pattern (200) is formed in various shapes. For example, the first metal pattern (200) may be formed in a square, triangular, circular, or octagonal shape.

[0065]

[0066] The second metal pattern (300) is disposed between the insulating layers. Specifically, the second metal pattern is disposed on each of the insulating layers. Specifically, the second metal pattern (300) includes a 2-1 metal pattern (310), a 2-2 metal pattern (320), and a 2-3 metal pattern (330). The 2-1 metal pattern (310) is disposed on the first insulating layer (110). The 2-2 metal pattern (320) is disposed on the second insulating layer (120). The 2-3 metal pattern (330) is disposed on the third insulating layer (130).

[0067] The second metal pattern (300) may include at least one metal selected from the group consisting of gold (Au), silver (Ag), platinum (Pt), titanium (Ti), tin (Sn), copper (Cu), zinc (Zn), and alloys thereof. The second metal pattern (300) may include the same metal as the first metal pattern (200). Preferably, the second metal pattern (300) includes copper (Cu).

[0068] The second metal pattern (300) transmits a signal received from the first metal pattern (200). The second metal pattern (300) is a wiring pattern that transmits a signal. That is, the second metal pattern (300) is a transmission line that transmits a signal from the antenna substrate (1000).

[0069]

[0070] The above via (V) includes a via hole (VH) and a via electrode (VE).

[0071] The above via hole (VH) is formed by penetrating the insulating layer (100). At least one via hole (VH) can be formed in each insulating layer (110, 120, 130, 140).

[0072] The via electrode (VE) is positioned inside the via hole (VH). The via electrode (VE) may include the same material as the first metal pattern (200) and the second metal pattern (300). For example, the via electrode (VE) may include copper.

[0073] The second metal layers arranged on different layers are electrically connected by the via (V). Accordingly, a signal received by the first metal pattern (200) can be transmitted to an external component. Specifically, the signal received by the first metal pattern (200) is transmitted to the second metal pattern (300) by the via (V). In addition, the signal moves through the second metal pattern (300) and is transmitted to the third metal pattern (400) arranged on the fourth insulating layer (140), which is the lowest insulating layer. Accordingly, the signal is transmitted to an external electronic component connected to the antenna substrate by the third metal pattern (400).

[0074] A bonding area is formed between the second metal pattern (300) and the via (V). For example, a bonding layer (CL) is disposed between the second metal pattern (300) and the via (V). The insulating layers and the insulating layer and the second metal pattern are bonded by a thermocompression process. However, the second metal pattern (300) and the via (V) are not bonded by the thermocompression process. Therefore, the bonding layer (CL) can bond the second metal pattern (300) and the via (V).

[0075] The above bonding layer (CL) may include tin. Specifically, the bonding layer (CL) may include a copper-tin alloy. For example, the bonding layer (CL) may include a Cu3Sn alloy.

[0076]

[0077] As previously explained, the insulating layers are bonded by the thermocompression process. However, depending on the conditions of the thermocompression process, the bonding strength of the insulating layers may vary. Alternatively, if the antenna substrate is exposed to a high temperature and / or high humidity environment, the bonding strength of the insulating layers may vary. Accordingly, the bonding strength of the insulating layers may decrease. Alternatively, the bonding strength of the insulating layer and the second metal pattern may decrease.

[0078] Accordingly, the reliability and driving characteristics of the antenna substrate may be reduced.

[0079] The antenna substrate (1000) according to the embodiment controls the conditions of the thermocompression process. This allows the bonding strength of the insulating layer to be optimized. Accordingly, the gap between the insulating layers or the gap between the insulating layer and the second metal pattern can be minimized.

[0080]

[0081] Figures 4 to 6 are drawings for explaining the manufacturing process of the antenna substrate.

[0082] Referring to Fig. 4, first, each insulating layer is prepared. Specifically, the first insulating layer (110), the second insulating layer (120), the third insulating layer (130), and the fourth insulating layer (140) are prepared.

[0083] The second metal pattern (310, 320, 330) is disposed on the first insulating layer (110), the second insulating layer (120), and the third insulating layer (130). In addition, the first metal pattern (200) is disposed on the fourth insulating layer (140). The first metal pattern (200) is disposed on the via (V4).

[0084] A bonding metal (500) is disposed on at least one of the plurality of vias (V). The bonding metal (500) is disposed on the second metal pattern (300). In detail, the bonding metal (500) is disposed on an area where the vias (V) are connected.

[0085] The above bonding metal (500) may include a material capable of bonding the via and the second metal pattern (300). For example, the bonding metal (500) may include tin (Sn).

[0086] Next, the insulating layers are aligned. By this, the positions of the vias (V1, V2, V3, V4) can be aligned.

[0087]

[0088] Referring to FIG. 5, the insulating layers are bonded. The insulating layers are bonded by a thermocompression process. Specifically, the bonding layers are bonded by heat and pressure within a set range.

[0089] The bonding temperature, bonding pressure, and bonding time of the above thermocompression bonding process can be controlled. This allows the adhesion of the insulating layer to be optimized.

[0090] The above bonding temperature has a set range. The bonding temperature may be similar to the melting point of the insulating layer. For example, when the insulating layer (100) includes a liquid crystal polymer material, the bonding temperature may be similar to the melting point of the liquid crystal polymer material.

[0091] For example, the bonding temperature may be greater than 300°C. Specifically, the bonding temperature may be greater than 300°C to 315°C. More specifically, the bonding temperature may be between 305°C and 313°C or between 308°C and 311°C.

[0092] The above bonding pressure has a set range. For example, the insulating layer (100) may include a liquid crystal polymer material. In this case, the bonding pressure may be 35 MPa to 45 MPa, 37 MPa to 43 MPa, or 39 MPa to 41 MPa.

[0093] The bonding time has a set range. For example, the insulating layer (100) may include a liquid crystal polymer material. In this case, the bonding time may be 25 to 35 minutes, 27 to 33 minutes, or 29 to 31 minutes.

[0094] The insulating layer can have an optimal bonding strength under the conditions of the above bonding temperature, the above bonding pressure, and the above bonding time. Accordingly, the interlayer adhesive strength of the antenna substrate can be increased. Specifically, the interlayer adhesive strength of the antenna substrate can be 0.5 kgf or more. More specifically, the interlayer adhesive strength of the antenna substrate can be 0.5 kgf to 1.5 kgf, 0.8 kgf to 1.4 kgf, or 1.0 kgf to 1.3 kgf.

[0095] The interlayer adhesion can be measured by a adhesion test. Specifically, before thermally compressing the insulating layers, a specimen is inserted into one of the interlayer regions. Then, after bonding the insulating layers, the force required to remove the specimens is measured. The interlayer adhesion is calculated as an average value obtained by repeating the above steps several times.

[0096]

[0097] Referring to Fig. 6, the insulating layers are bonded by the thermocompression process. Next, a third metal pattern (400) is placed on the first insulating layer (110). The third metal pattern is placed on the via (V1). The antenna substrate (1000) is connected to other electronic components by the third metal pattern (400). For example, the antenna substrate (1000) may be connected to a chip or a printed circuit board.

[0098]

[0099] Referring to FIG. 7, a gap may be formed between the insulating layer and the second metal pattern. Specifically, a first gap (G1) is formed between the 2-1 metal pattern (310) and the second insulating layer (120). In addition, a second gap (G2) is formed between the 2-2 metal pattern (320) and the third insulating layer (130). In addition, a third gap (G3) is formed between the 2-3 metal pattern (330) and the fourth insulating layer (140).

[0100] The sizes of the above gaps (G1, G2, G3) can be controlled. Specifically, the temperature, pressure, and time of the thermocompression process are controlled. This enhances the adhesive strength of the insulating layer. Accordingly, the sizes of the gaps (G1, G2, G3) can be controlled within a set range.

[0101] The above gaps (G1, G2, G3) each have a height (H1, H2, H3). The heights (H1, H2, H3) are defined as maximum heights. The heights (H1, H2, H3) may be the sizes of the gaps (G1, G2, G3). The heights (H1, H2, H3) may be less than or equal to a thickness of the insulating layer. In detail, the heights (H1, H2, H3) may be less than or equal to 10% of the thickness of the insulating layer. More specifically, the heights (H1, H2, H3) may be 0.1% to 10%, 0.5% to 5%, or 1% to 3% of the thickness of the insulating layer.

[0102] For example, the heights (H1, H2, H3) may be 10 μm or less. In detail, the heights (H1, H2, H3) may be 10 μm or less. More specifically, the heights (H1, H2, H3) may be 0.1 μm to 10 μm, 0.5 μm to 5 μm, or 1 μm to 3 μm.

[0103] If the above heights (H1, H2, H3) exceed the above range, the transmission loss of the antenna substrate may increase. Additionally, external impurities may enter through the gap. Accordingly, the reliability of the antenna substrate may decrease.

[0104]

[0105] The size of any one of the above gaps (G1, G2, G3) may be different from the sizes of the other gaps. For example, the size of the second gap (G2) may be larger than the sizes of the first gap (G1) and the third gap (G3). The second insulating layer (120) may be a core layer. Accordingly, the thickness of the second insulating layer (120) may be larger than the thicknesses of the other insulating layers. Accordingly, the size of the second gap (G2) may be formed to be the largest. However, since the bonding strength of the insulating layer is optimized, the size of the second gap (G2) may be controlled within the above range.

[0106]

[0107] The first gap (G1), the second gap (G2), and the third gap (G3) have deviations within a set range. In detail, the deviations of the first gap (G1), the second gap (G2), and the third gap (G3) may be 5% or less of the thickness of the insulating layer. More specifically, the deviations may be 0.1% to 5%, 0.5% to 4%, or 1% to 2% of the thickness of the insulating layer.

[0108] For example, the deviation of the first gap (G1), the second gap (G2), and the third gap (G3) may be 0.1 μm to 5 μm, 0.5 μm to 4 μm, or 1 μm to 2 μm.

[0109] As the adhesive strength of the insulating layers increases, the gap size between each layer decreases. Accordingly, the gap deviation between the insulating layers also decreases.

[0110] Accordingly, the transmission loss of signals moving through each of the above layers can be reduced.

[0111]

[0112] Hereinafter, the adhesion characteristics of the antenna substrate according to the conditions of the thermal compression process are described through examples and comparative examples.

[0113]

[0114] Experimental Example 1

[0115] Antenna substrates of the examples and comparative examples are manufactured by the following process.

[0116] A plurality of insulating layers are prepared. The insulating layers are liquid crystal polymer (LCP). A copper layer is placed on each of the insulating layers.

[0117] Next, a via is formed in each insulating layer, the via including copper.

[0118] Next, tin is placed on the copper layer corresponding to the via.

[0119] Next, multiple insulating layers are bonded using a pressing device.

[0120] The process conditions of the above pressing equipment are as shown in Table 1.

[0121] Next, the degree of lifting (gap) and interlayer adhesion of Example 1 and Comparative Examples 1 and 2 were measured.

[0122] The above excitation degree was measured by excitation of the insulating layer and copper.

[0123] The interlayer adhesion was measured by measuring the adhesion between the insulating layers and the adhesion between the insulating layer and the second metal pattern.

[0124]

[0125] Example 1 Comparative Example 1 Comparative Example 2 Temperature (℃) 310 290 300 Pressure (MPa) 30 30 30 Time (min) 444

[0126] Example 1 Comparative Example 1 Comparative Example 2 Lifting Degree (㎛) 0.150 20 Interlayer Adhesion (kgf) 1.25 0.6 1 0.48

[0127] Referring to Tables 1, 2, and FIGS. 8 to 10, Example 1 has a bonding temperature that is nearly identical to the melting point of the insulating layer. Furthermore, Example 1 has a very small gap between the insulating layer and copper. In other words, since the bonding temperature is nearly identical to the melting point of the insulating layer, the adhesive strength of the insulating layer is enhanced.

[0128] On the other hand, in Comparative Examples 1 and 2, the bonding temperature is different from the melting point of the insulating layer, that is, the bonding temperature is different by more than 10°C from the melting point of the insulating layer. In addition, it can be seen that in Comparative Examples 1 and 2, the gap between the insulating layer and copper is very large. That is, since the bonding temperature is different from the melting point of the insulating layer, it can be seen that the adhesive strength of the insulating layer is reduced.

[0129]

[0130] Experimental Example 2

[0131] The insulating layers are bonded using the same method as in Experimental Example 1. Specifically, eight insulating layers are bonded by thermocompression.

[0132] Next, a heat accelerated test (HAST) is performed. The heat accelerated test is performed under conditions of a temperature of 130°C, humidity of 85%, and a pressure of 230 kPa. The antenna substrates of Example 2 and Comparative Example 3 are exposed under the above conditions for 196 hours.

[0133] Next, the degree of lifting (gap) and interlayer adhesion of Example 1 and Comparative Examples 1 and 2 were measured.

[0134] The above excitation degree was measured by excitation of the insulating layer and copper.

[0135] The interlayer adhesion was measured by measuring the adhesion between the insulating layers and the adhesion between the insulating layer and the second metal pattern.

[0136]

[0137] Example 2 Comparative Example 3 Lifting degree (㎛) 0.1100 Interlayer adhesion (kgf) 1.25 0.38

[0138] Referring to Table 3, Figures 11 and 12, it can be seen that the antenna substrate of Example 2 maintains the degree of lifting and interlayer adhesion after the thermal acceleration test. In Example 2, the bonding temperature is almost similar to the melting point of the insulating layer. That is, since the bonding temperature is almost similar to the melting point of the insulating layer, it can be seen that the adhesive strength of the insulating layer is increased.

[0139] Accordingly, it can be seen that the adhesive strength of the insulating layer is maintained even when the antenna substrate is exposed to a high temperature and humid environment for a long period of time.

[0140] On the other hand, it can be seen that the antenna substrate of Comparative Example 3 shows an increase in the degree of lifting after the thermal acceleration test. In addition, it can be seen that the interlayer adhesion of the antenna substrate of Comparative Example 3 shows a decrease after the thermal acceleration test. In Comparative Example 3, the bonding temperature is different from the melting point of the insulating layer, that is, the bonding temperature is different by 10°C or more from the melting point of the insulating layer. That is, since the bonding temperature is different from the melting point of the insulating layer, it can be seen that the adhesive strength of the insulating layer decreases.

[0141] Accordingly, it can be seen that when the antenna substrate is exposed to a high temperature and humid environment for a long period of time, the adhesive strength of the insulating layer is reduced.

[0142]

[0143] Additionally, the names of each insulating layer and metal pattern may be referred to differently by the structure described above.

[0144] Accordingly, an antenna substrate according to an embodiment includes an insulating layer; a metal pattern disposed on the insulating layer, a first gap is provided between the metal pattern and the insulating layer, and a height of the first gap is 0.1% to 10% of a thickness of the insulating layer.

[0145] In addition, the insulating layer includes a first insulating layer; and a second insulating layer disposed on the first insulating layer, and the metal pattern includes a first metal pattern disposed on the second insulating layer, and a second metal pattern disposed between the first insulating layer and the second insulating layer, and the first gap is provided between the first insulating layer and the first metal pattern.

[0146] In addition, it further includes a second gap provided between the first insulating layer and the second insulating layer, and the height of the second gap is 0.1% to 10% of the thickness of the first insulating layer.

[0147] Additionally, the thickness of the first insulating layer is 25 µm to 150 µm.

[0148] Additionally, the height of the first gap or the second gap is 0.1 μm to 10 μm.

[0149] Additionally, the antenna substrate further includes a via electrode penetrating the second insulating layer in a vertical direction; and a bonding layer disposed between the via electrode and the second metal pattern.

[0150] Additionally, the bonding layer comprises a copper-tin alloy.

[0151] Additionally, at least one of the adhesive force between the first insulating layer and the second insulating layer and the adhesive force between the first insulating layer and the second metal pattern is 0.5 kgf to 1.5 kgf.

[0152] Meanwhile, an antenna substrate according to another embodiment includes an insulating structure including a lower insulating layer, an inner insulating layer disposed on the lower insulating layer, and an upper insulating layer disposed on the inner insulating layer; and a metal pattern including an upper metal pattern disposed on the upper insulating layer, and a first inner metal pattern disposed between the lower insulating layer and the inner insulating layer, and a second inner metal pattern disposed between the inner insulating layer and the upper insulating layer, wherein a gap is included in at least one of between the lower insulating layer and the first inner metal pattern, between the inner insulating layer and the second inner metal pattern, between the lower insulating layer and the inner insulating layer, and between the inner insulating layer and the upper insulating layer, and wherein a height of the gap is 0.1% to 10% of a thickness of any one of the lower insulating layer, the inner insulating layer, and the upper insulating layer.

[0153] Additionally, the inner insulating layer includes a first inner insulating layer and a second inner insulating layer disposed on the first inner insulating layer, and a thickness of the first inner insulating layer is different from a thickness of the second inner insulating layer.

[0154] Additionally, the thickness of the first inner insulating layer is different from the thicknesses of the lower insulating layer and the upper insulating layer, respectively.

[0155] Additionally, the thickness of the first inner insulating layer is greater than the thickness of each of the second inner insulating layer, the lower insulating layer, and the upper insulating layer.

[0156] In addition, the metal pattern further includes a third inner metal pattern disposed between the first inner insulating layer and the second inner insulating layer,

[0157] In addition, the gap includes a first gap provided between the lower insulating layer and the first inner metal pattern, a second gap arranged between the first inner insulating layer and the third inner metal pattern, and a third gap arranged between the second inner insulating layer and the upper insulating layer.

[0158] Additionally, the height of the second gap is different from the heights of the first and third gaps.

[0159] Additionally, the height of the second gap is greater than the heights of the first and third gaps.

[0160] Additionally, the deviation in height of the first gap to the third gap is 0.1% to 5% of the thickness of the insulating layer of any one of the lower insulating layer, the first inner insulating layer, the second inner insulating layer, and the upper insulating layer.

[0161] Additionally, the above deviation is 0.1㎛ to 5㎛.

[0162]

[0163] An antenna substrate according to an embodiment includes a plurality of insulating layers. The insulating layers are bonded by a thermocompression process. The thermocompression process is performed at a set range of temperature, pressure, and time. In detail, the bonding temperature is similar to the melting point of the insulating layer. Accordingly, the adhesive strength of the insulating layer can be increased. Accordingly, the interlayer lifting of the antenna substrate is reduced, and the interlayer adhesion is improved. Accordingly, the signal loss of the antenna substrate according to the embodiment is reduced.

[0164] Additionally, even if the antenna substrate is exposed to a high temperature and high humidity environment for a long period of time, the adhesive strength of the insulating layer is maintained. Therefore, the operating characteristics of the antenna substrate do not change depending on the usage environment.

[0165] Accordingly, the driving characteristics and reliability of the antenna substrate according to the embodiment are improved.

[0166]

[0167] Hereinafter, an antenna module according to an embodiment will be described with reference to FIG. 13.

[0168] Referring to FIG. 13, the antenna module includes the antenna substrate. In detail, the antenna module (3000) includes an antenna substrate (1000) and a printed circuit board (2000).

[0169] The printed circuit board (2000) includes a circuit board (2100) and a chip (C) placed on the circuit board (2100). For example, the circuit board (2100) may include a rigid printed circuit board (PCB) or a flexible flexible printed circuit board (FPCB). In addition, the chip (C) includes an RF chip.

[0170] The above antenna substrate (1000) is connected to the chip package (2000). Specifically, solder (S) is placed between the third metal pattern (400) of the antenna substrate (1000) and the pad portion (2200) of the printed circuit board (2000). Then, heat is applied to connect the antenna substrate (1000) and the chip package (2000).

[0171] Although the drawing illustrates the connection between the antenna substrate and the printed circuit board, the embodiment is not limited thereto. For example, the antenna substrate may be connected to the chip. Specifically, the third metal pattern (400) and the terminal of the chip may be directly connected.

[0172]

[0173] The features, structures, effects, etc. described in the above-described embodiments are included in at least one embodiment of the present invention, and are not necessarily limited to just one embodiment. Furthermore, the features, structures, effects, etc. exemplified in each embodiment can be combined or modified in other embodiments by those skilled in the art to which the embodiments pertain. Therefore, the contents related to such combinations and modifications should be construed as being included within the scope of the present invention.

[0174] In addition, although the above description focuses on embodiments, these are merely examples and do not limit the present invention. Those skilled in the art to which the present invention pertains will appreciate that various modifications and applications not exemplified above are possible without departing from the essential characteristics of the present embodiment. For example, each component specifically shown in the embodiments can be modified and implemented. In addition, differences related to such modifications and applications should be interpreted as being included within the scope of the present invention defined in the appended claims.

Claims

1. Insulating layer; including a metal pattern disposed on the insulating layer, A first gap is provided between the metal pattern and the insulating layer, An antenna substrate, wherein the height of the first gap is 0.1% to 10% of the thickness of the insulating layer.

2. In paragraph 1, The insulating layer includes a first insulating layer; and a second insulating layer disposed on the first insulating layer, The above metal pattern is, A first metal pattern disposed on the second insulating layer, and A second metal pattern disposed between the first insulating layer and the second insulating layer, An antenna substrate, wherein the first gap is provided between the first insulating layer and the first metal pattern.

3. In paragraph 2, Further comprising a second gap provided between the first insulating layer and the second insulating layer, An antenna substrate, wherein the height of the second gap is 0.1% to 10% of the thickness of the first insulating layer.

4. In paragraph 3, An antenna substrate wherein the thickness of the first insulating layer is 25 ㎛ to 150 ㎛.

5. In paragraph 3, An antenna substrate wherein the height of the first gap or the second gap is 0.1 μm to 10 μm.

6. In paragraph 3, A via electrode penetrating the second insulating layer in a vertical direction; and An antenna substrate further comprising a bonding layer disposed between the via electrode and the second metal pattern.

7. In paragraph 6, The above bonding layer is an antenna substrate comprising a copper-tin alloy.

8. In paragraph 3, An antenna substrate wherein at least one of the adhesive force between the first insulating layer and the second insulating layer and the adhesive force between the first insulating layer and the second metal pattern is 0.5 kgf to 1.5 kgf.

9. An insulating structure including a lower insulating layer, an inner insulating layer disposed on the lower insulating layer, and an upper insulating layer disposed on the inner insulating layer; and A metal pattern including an upper metal pattern disposed on the upper insulating layer, a first inner metal pattern disposed between the lower insulating layer and the inner insulating layer, and a second inner metal pattern disposed between the inner insulating layer and the upper insulating layer, A gap is included in at least one of the following: between the lower insulating layer and the first inner metal pattern, between the inner insulating layer and the second inner metal pattern, between the lower insulating layer and the inner insulating layer, and between the inner insulating layer and the upper insulating layer; An antenna substrate, wherein the height of the gap is 0.1% to 10% of the thickness of any one of the lower insulating layer, the inner insulating layer, and the upper insulating layer.

10. In paragraph 9, The inner insulating layer includes a first inner insulating layer and a second inner insulating layer disposed on the first inner insulating layer, An antenna substrate, wherein the thickness of the first inner insulating layer is different from the thickness of the second inner insulating layer.

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