High-frequency signal transmission lines and electronic equipment

Abstract

A high-frequency signal transmission line (102) is provided with: a resin laminate part in which first resin layers (11, 12, 13) and second resin layers (21, 22) are laminated; a signal conductor pattern (4) formed on the first resin layer (11); and ground conductor layers (51, 52) that face the signal conductor pattern across the resin laminate part. Opening portions are formed in the first resin layers (11, 12) at a position along the signal conductor pattern (4) in the resin laminate part so that a hollow portion (HP) is provided in the resin laminate part at the opening portions. The second resin layers (22) in contact with the first resin layers (11, 12) having the opening portions are provided with a maximum thickness and a minimum thickness that are different in the opening portions formed in the first resin layers so that the second resin layers in contact with the first resin layers are adhered to a part of end surfaces of the first resin layers (11, 12) at the opening portions.

Description

Technical Field

[0001] The present invention relates to a high-frequency signal transmission line and an electronic device including the same.

Background Art

[0002] Patent Document 1 discloses a suspended-structure transmission line in which a signal line is formed on a resin layer, and hollow portions are formed above and below the signal line. Further, the transmission line is configured such that a side surface of an adhesive layer in contact with the hollow portion has a concave shape.

Prior Art Literature

Patent Literature

[0003]

Patent Document 1

Summary of the Invention

Problem to be Solved by the Invention

[0004] In the high-frequency signal transmission line described in Patent Document 1, since the adhesive layer is only in contact with the upper and lower surfaces of the base layer, the adhesive strength of the laminate is low in the structure having the hollow portion. Further, since there is no adhesive layer above and below the hollow portion, the strength of the upper and lower layers of the hollow portion is low. Therefore, when the vicinity of the hollow portion of the high-frequency signal transmission line is deformed by an external force applied to the high-frequency signal transmission line, the electrical characteristics of the high-frequency signal transmission line become unstable.

[0005] Accordingly, an object of the present invention is to provide a high-frequency signal transmission line that maintains high strength of a resin laminated portion and a hollow portion and has stable electrical characteristics, and an electronic device including the same.

Means for Solving the Problem

[0006] As an example of the present disclosure, a high-frequency signal transmission line includes: The device comprises a resin laminate formed by laminating one or more first resin layers and one or more second resin layers, a signal conductor pattern arranged to be in contact with at least one of the first resin layers, and a ground conductor layer facing the signal conductor pattern with part or all of the resin laminate in between. In the resin laminate, an opening is formed in at least one of the first resin layers located along the signal conductor pattern, thereby providing a hollow portion in the resin laminate at the opening. The second resin layer in contact with the first resin layer in which the opening is formed is characterized in that the second resin layer in contact with the first resin layer is adhered to a part of the end face of the opening in the first resin layer in which the opening is formed. [Effects of the Invention]

[0007] According to the present invention, a high-frequency signal transmission line with high resistance to externally applied stress and stable electrical characteristics, as well as electronic equipment equipped therewith, can be obtained. [Brief explanation of the drawing]

[0008] [Figure 1] The upper part of Figure 1 is a plan view of the high-frequency signal transmission line 101 according to the first embodiment, and the lower part of Figure 1 is a longitudinal cross-sectional view of the portion indicated by the dashed line in the upper part of Figure 1. [Figure 2] Figure 2 is a plan view of the high-frequency signal transmission line 102 according to the second embodiment. [Figure 3] The upper part of Figure 3 is a longitudinal section of the area indicated by the dashed line AA in Figure 2, and the lower part of Figure 3 is a longitudinal section of the area indicated by the dashed line BB in Figure 2. [Figure 4] Figure 4 is a plan view of each layer during the manufacturing process of the high-frequency signal transmission line 102. [Figure 5] Figure 5 is a cross-sectional view of the high-frequency signal transmission line 103 according to the third embodiment. [Figure 6] Figure 6 is a cross-sectional view of the high-frequency signal transmission line 104 according to the fourth embodiment. [Figure 7]FIG. 7 is a cross-sectional view of a high-frequency signal transmission line 105 according to a fifth embodiment. [Figure 8] FIG. 8 is a cross-sectional view of a high-frequency signal transmission line 106 according to a sixth embodiment. [Figure 9] FIG. 9 is a cross-sectional view of a high-frequency signal transmission line 107 according to a seventh embodiment. [Figure 10] The upper part of FIG. 10 is a plan view of a high-frequency signal transmission line 108 according to an eighth embodiment, and the lower part of FIG. 10 is a longitudinal cross-sectional view taken along the one-dot chain line in the upper part of FIG. 10. [Figure 11] The upper part of FIG. 11 is a plan view of a high-frequency signal transmission line 109 according to a ninth embodiment, and the lower part of FIG. 11 is a longitudinal cross-sectional view taken along the one-dot chain line in the upper part of FIG. 11. [Figure 12] FIG. 12 is a plan view of high-frequency signal transmission lines 110A and 110B according to a tenth embodiment. [Figure 13] FIG. 13 is a plan view of a first resin layer 11 of four types of high-frequency signal transmission lines according to an eleventh embodiment. [Figure 14] FIG. 14 is a plan view of a first resin layer 11 of two types of high-frequency signal transmission lines according to the eleventh embodiment. [Figure 15] The upper part of FIG. 15 is a cross-sectional view of a high-frequency signal transmission line 112 according to a twelfth embodiment of the present invention. The lower part of FIG. 15 is a cross-sectional view of the high-frequency signal transmission line 112 showing the state of electric field distribution by electric lines of force. [Figure 16] FIG. 16 is a longitudinal cross-sectional view of a high-frequency signal transmission line 113A according to a thirteenth embodiment. [Figure 17] FIG. 17 is a longitudinal cross-sectional view of a high-frequency signal transmission line 113B according to the thirteenth embodiment. [Figure 18] FIG. 18 is a longitudinal cross-sectional view of a high-frequency signal transmission line 114 according to a fourteenth embodiment. MODE FOR CARRYING OUT THE INVENTION

[0009] Hereinafter, several specific examples will be given with reference to the drawings to illustrate a plurality of modes for carrying out the present invention. The same reference numerals are assigned to the same portions in each drawing. In consideration of facilitating the description or understanding of the key points, the embodiments are divided into a plurality of embodiments for convenience of description, but partial replacement or combination of the configurations shown in different embodiments is possible. From the second embodiment onwards, the description of matters common to the first embodiment is omitted, and only different points will be described. In particular, the same functions and effects achieved by similar configurations will not be sequentially described for each embodiment.

[0010] <<First Embodiment>> In the first embodiment, an example of a microstrip line type high-frequency signal transmission line will be described.

[0011] The upper part of FIG. 1 is a plan view of the high-frequency signal transmission line 101 according to the first embodiment, and the lower part of FIG. 1 is a longitudinal sectional view taken along the dashed-dotted line portion in the upper part of FIG. 1. Although a single high-frequency signal transmission line 101 is shown in FIG. 1, until the final manufacturing process, a large number of high-frequency signal transmission lines continuous in the plane direction are manufactured, and the product is separated into each individual high-frequency signal transmission line in the final process. This also applies to each embodiment described hereinafter.

[0012] This high-frequency signal transmission line 101 includes a resin laminated portion 3, a signal conductor pattern 4, and a ground conductor layer 5.

[0013] The resin laminated portion 3 is a portion obtained by laminating first resin layers 11, 12, 13 and second resin layers 21, 22. The signal conductor pattern 4 is formed on an upper surface of the first resin layer 11. The ground conductor layer 5 is laminated on an upper surface of the first resin layer 13. That is, the signal conductor pattern 4 and the ground conductor layer 5 face each other across a part of the resin laminated portion 3.

[0014] Circular openings are formed in the first resin layer 12 and the second resin layer 21. In terms of the shape shown in the drawing, the openings are circular when viewed in the lamination direction of the first resin layers 11, 12, 13 and the second resin layers 21, 22.

[0015] Thus, an opening is formed in the first resin layer 12 of the resin laminated portion 3 at a position along the signal conductor pattern 4, and a hollow portion HP is provided in the resin laminated portion 3 at this opening. In particular, in this embodiment, a hollow portion HP is formed where the first resin layer 12 and the second resin layer 22 do not come into contact with the signal conductor pattern 4.

[0016] In this invention, not limited to this embodiment, "lamination direction" refers to the direction of the stacking order of each layer during manufacturing, but rather to the direction of the stacking of each layer in the illustrated state.

[0017] As shown at the top of Figure 1, this high-frequency signal transmission line 101 has six hollow sections HP. In other words, the signal conductor pattern 4 passes through these six hollow sections HP. This high-frequency signal transmission line 101 functions as a microstrip line consisting of the signal conductor pattern 4, the ground conductor layer 5, a part of the resin laminate 3, and the hollow sections HP.

[0018] Furthermore, if the spacing between adjacent hollow sections HP is less than 1 / 4 wavelength of the transmitted signal, the periodic change in characteristic impedance due to the change in relative permittivity around the signal conductor pattern 4 will not be a problem.

[0019] As shown in the upper part of Figure 1, signal conductor pattern terminals 4T, separated from the ground conductor layer 5, are formed on the upper surface of the resin laminate 3. The ends of the signal conductor pattern 4 are connected to the signal conductor pattern terminals 4T via interlayer connecting conductors. A coaxial connector 61 is mounted on the upper signal conductor pattern terminal 4T, and a coaxial connector 62 is mounted on the lower signal conductor pattern terminal 4T. In this way, the high-frequency signal transmission line 101 is used as a transmission line with coaxial connectors at both ends. The mounting positions of the coaxial connectors 61 and 62 in Figure 1 are shown.

[0020] The signal conductor pattern 4 and the ground conductor layer 5 are both made of copper foil, for example. The materials of the first resin layers 11, 12, and 13 are, for example, polyimide, liquid crystal polymer, or epoxy resin. The materials of the second resin layers 21 and 22 are, for example, thermoplastic polyimide, fluororesin, or polyolefin resin. Polyolefin resins include, for example, styrene, polyethylene, and polypropylene. These second resin layers 21 and 22 act as adhesive layers that bond adjacent first resin layers 11, 12, and 13 together.

[0021] The flexibility of the second resin layers 21 and 22 at room temperature is greater than that of the first resin layers 11, 12, and 13 at room temperature. Here, room temperature is, for example, 25°C or room temperature.

[0022] For example, the Young's modulus of the second resin layers 21 and 22 is 1 MPa or less, while the Young's modulus of the first resin layers 11, 12, and 13 is 2 MPa or more.

[0023] Furthermore, it is desirable that the second resin layers 21 and 22 have high fluidity during processing. It is also acceptable for them to flow, bond a portion of the end face (inner end face) at the opening, and then harden. As for the material of the second resin layers 21 and 22, for example, prepreg material used for interlayer bonding can be considered.

[0024] Furthermore, the relative permittivity of the second resin layer is lower than that of the first resin layer. For example, the relative permittivity of the second resin layers 21 and 22 is 2.2 to 2.8, while the relative permittivity of the first resin layers 11, 12, and 13 is 2.8 to 4.0.

[0025] Furthermore, the dielectric loss tangent of the second resin layer is lower than that of the first resin layer. For example, the dielectric loss tangents of the second resin layers 21 and 22 are 0.0005 to 0.003, while the dielectric loss tangents of the first resin layers 11, 12, and 13 are 0.002 to 0.01.

[0026] Note that either the relative permittivity relationship or the dielectric loss tangent relationship may satisfy the above relationship even if only one of them is true.

[0027] The second resin layer 22, which is in contact with the first resin layer 12 in which an opening is formed, adheres to a portion of the end face (inner end face) of the opening in the first resin layer 12 because the maximum and minimum thicknesses of the second resin layer 22 differ at the opening in the first resin layer 12. In other words, the second resin layer 22 adheres to a portion of the end face (inner surface) of the opening in the first resin layer 12, forming an adhesive portion SA.

[0028] Furthermore, in this embodiment, the portion of the second resin layer that forms part of the hollow section (part of the second resin layer 22) is a curved surface that extends outward from the center of the hollow section HP compared to the periphery of the hollow section HP. This curved surface is, for example, when a, b, and c are half the length of the diameters in the X, Y, and Z axes, respectively, x 2 / a 2 +y 2 / b 2 +z 2 / c 2 This is the surface of an ellipsoid represented by a = 1. In the cross-section shown at the bottom of Figure 1, the surface forms an elliptical arc. If a = b = c, then the cross-section of the surface is a circular arc.

[0029] The second resin layer 22 has a curved surface that extends outward from the hollow portion near its center compared to the periphery of the hollow portion, but the first resin layer 13 and the second resin layer 22 are bonded together over their entire surface. In other words, the first resin layer 13 is not exposed inside the hollow portion HP.

[0030] The portion FA shown at the bottom of Figure 1 indicates an adhesive portion where the thickness of the second resin layer 22 is thinner than that of the adhesive portion SA, yet it is still bonded to the first resin layer 13.

[0031] This embodiment provides the following effects and benefits.

[0032] (a) Since the second resin layer 22, which is an adhesive layer, also adheres to the end face (inner surface) of the opening of the first resin layer 12, the adhesion strength between the second resin layer 22 and the first resin layer 12 is high. As a result, the strength of the hollow portion HP is high, stress applied to the high-frequency signal transmission line 101 from the outside is reduced, and damage such as peeling between each layer is prevented.

[0033] (b) The portion of the resin laminate 3 that forms part of the hollow section HP is a curved surface that extends outward from the hollow section HP near the center compared to the periphery of the hollow section HP, so the air layer near the signal conductor pattern 4 is thicker. As a result, both the dielectric loss tangent and dielectric constant of the dielectric between the signal conductor pattern 4 and the ground conductor layer 5 are small, and the dielectric loss of the high-frequency signal transmission line is reduced.

[0034] (c) Rather than the first resin layer, which has relatively low flexibility, the portion of the second resin layer, which has relatively high flexibility, that forms part of the hollow section is a curved surface that extends outward from the hollow section near the center rather than around the hollow section. Therefore, the stress applied to the high-frequency signal transmission line 101 from the outside is effectively relieved by the second resin layer, and the reduction in strength due to the presence of the hollow section HP is suppressed.

[0035] (d) If the relative permittivity of the second resin layer adjacent to the signal conductor pattern 4 is lower than that of the first resin layer, the above-mentioned effect of reducing dielectric loss is excellent. Similarly, if the dielectric loss tangent of the second resin layer adjacent to the signal conductor pattern 4 is lower than that of the first resin layer, the above-mentioned effect of reducing dielectric loss is excellent.

[0036] (e) The second resin layer 22 has a curved surface that extends outward from the hollow portion HP near the center compared to the periphery of the hollow portion HP, and the first resin layer 13 and the second resin layer 22 are bonded together over their entire surface, so the bonding strength between the first resin layer 13 and the second resin layer 22 is high. As a result the strength of the hollow portion HP is high, stress applied to the high-frequency signal transmission line 101 from the outside is reduced, and damage is prevented.

[0037] (f) Figure 1 shows a configuration in which the signal conductor pattern 4 is exposed within the hollow portion HP, but a configuration in which the signal conductor pattern 4 is formed on the lower surface of the first resin layer 11 (the surface opposite to the surface on which the hollow portion HP is formed) is also conceivable. In this case, it becomes easier to secure the distance between the ground conductor layer 5 and the signal conductor pattern 4. Therefore, the line width of the signal conductor pattern can be increased to obtain a predetermined characteristic impedance, and thereby the transmission loss can be reduced.

[0038] 《Second Embodiment》 In the second embodiment, an example of a stripline-type high-frequency signal transmission line in which a hollow section HP exists around the signal conductor pattern 4 is shown.

[0039] Figure 2 is a plan view of the high-frequency signal transmission line 102 according to the second embodiment. The upper part of Figure 3 is a longitudinal cross-sectional view of the portion indicated by the dashed line AA in Figure 2, and the lower part of Figure 3 is a longitudinal cross-sectional view of the portion indicated by the dashed line BB in Figure 2.

[0040] This high-frequency signal transmission line 102 comprises an upper resin laminate 31, a lower resin laminate 32, a signal conductor pattern 4, a first ground conductor layer 51, a second ground conductor layer 52, a ground conductor pattern 5C, and an interlayer connecting conductor 5V.

[0041] The upper resin laminated section 31 is the portion where the upper first resin layers 11, 12, 13 and the second resin layers 21, 22 are laminated. The lower resin laminated section 32 is the portion where the lower first resin layer 13 and the lower second resin layer 22 are laminated. In other words, the resin laminated section consists of the upper resin laminated section 31, which is laminated in the first lamination direction SD1 of the lamination directions of the first and second resin layers, and the lower resin laminated section 32, which is configured in the second lamination direction SD2, which is the opposite direction to the first lamination direction SD1.

[0042] The signal conductor pattern 4 and the ground conductor pattern 5C are formed on the upper surface of the first resin layer 11. The first ground conductor layer 51 is laminated on the upper surface of the upper first resin layer 13. The second ground conductor layer 52 is laminated on the lower surface of the lower first resin layer 13. In other words, the signal conductor pattern 4, the first ground conductor layer 51, and the second ground conductor layer 52 are facing each other with the upper resin laminated section 31 and the lower resin laminated section 32 in between.

[0043] As shown in the lower part of Figure 3, interlayer connecting conductors 5V are formed in the upper resin laminate 31. These interlayer connecting conductors 5V electrically connect the first ground conductor layer 51 and the ground conductor pattern 5C. Interlayer connecting conductors 5V are also formed in the lower resin laminate 32. These interlayer connecting conductors 5V electrically connect the second ground conductor layer 52 and the ground conductor pattern 5C.

[0044] Circular openings are formed in the first resin layers 11, 12 and the second resin layer 21. Represented in the drawing, these openings are circular when viewed in the stacking direction of the first resin layers 11, 12, 13 and the second resin layers 21, 22.

[0045] Thus, an opening is formed in the first resin layer 12 of the upper resin laminate 31 at a position along the signal conductor pattern 4, and this opening provides a hollow portion HP around the signal conductor pattern 4. In particular, in this embodiment, a hollow portion HP is formed where the first resin layers 11, 12 and the second resin layers 21, 22 do not come into contact with the signal conductor pattern 4.

[0046] As shown in Figure 2, this high-frequency signal transmission line 102 has six hollow sections HP. In other words, the signal conductor pattern 4 passes through these six hollow sections HP. This high-frequency signal transmission line 102 functions as a strip line consisting of the signal conductor pattern 4, the first ground conductor layer 51, the second ground conductor layer 52, the upper resin laminate 31, the lower resin laminate 32, and the hollow sections HP.

[0047] Similar to the example shown in the first embodiment, if the spacing between the hollow sections HP is less than 1 / 4 wavelength of the transmitted signal, the periodic change in characteristic impedance due to the change in relative permittivity around the signal conductor pattern 4 is not a problem.

[0048] The signal conductor pattern 4, the first ground conductor layer 51, and the second ground conductor layer 52 are all made of copper foil, for example. The materials of the first resin layers 11, 12, and 13 are, for example, polyimide, liquid crystal polymer, or epoxy resin. The materials of the second resin layers 21 and 22 are, for example, thermoplastic polyimide, fluororesin, or polyolefin resin. Polyolefin resins include, for example, styrene, polyethylene, and polypropylene. These second resin layers 21 and 22 act as adhesive layers that bond adjacent first resin layers 11, 12, and 13 together.

[0049] The relationship between the flexibility of the second resin layers 21, 22 and the first resin layers 11, 12, 13, the relationship between the relative permittivity of the second resin layers 21, 22 and the first resin layers 11, 12, 13, and the relationship between the dielectric loss tangent of the second resin layers 21, 22 and the first resin layers 11, 12, 13 are the same as those shown in the example of the first embodiment.

[0050] In the upper part of Figure 3, the portion indicated by the dashed line at the top of the figure is the adhesive portion SA, where the upper second resin layer 22 is bonded to a part of the end face (inner surface) of the opening of the first resin layer 12.

[0051] In the upper part of Figure 3, the portion FA indicated by the dashed line at the top of the figure represents the adhesive portion where the upper second resin layer 22 is bonded to the upper first resin layer 13, even though its film thickness has become thinner than its original thickness.

[0052] Furthermore, the portion indicated by the dashed line at the bottom of the figure is the adhesive portion SA where the lower second resin layer 22 is bonded to a part of the end face (inner surface) at the opening of the first resin layer 11.

[0053] In the upper part of Figure 3, the portion FA shown by the dashed line at the bottom of the figure indicates the adhesive portion where the lower second resin layer 22 is bonded to the lower first resin layer 13, even though its film thickness has become thinner than its original thickness.

[0054] Figure 4 is a plan view of each layer during the manufacturing process of the high-frequency signal transmission line 102. As already shown, the high-frequency signal transmission line 102 comprises, listed from top to bottom, a first resin layer 13, a second resin layer 22, a first resin layer 12, a second resin layer 21, a first resin layer 11, a second resin layer 22, and a first resin layer 13. Circular openings OH are formed in the first resin layers 11, 12 and the second resin layer 21. When these resin layers are stacked and pressurized and heated, as shown in the upper part of Figure 3, the melting of the upper second resin layer 22 causes it to extend to the end face (inner surface) of the opening in the first resin layer 12. Similarly, the melting of the lower second resin layer 22 causes it to extend to the end face (inner surface) of the opening in the first resin layer 11. In addition, the hollow portion HP formed by the overlapping openings OH expands due to heating. In other words, the hollow portion HP expands in the lamination direction as the film thickness of the upper second resin layer 22 becomes thinner than the original thickness of the upper second resin layer 22, and as the film thickness of the lower second resin layer 22 becomes thinner than the original thickness of the lower second resin layer 22.

[0055] The interlayer connecting conductor 5V shown in Figure 3 is formed by creating an opening on the outer surface of the laminate formed by stacking the above resin layers using laser processing to expose the ground conductor pattern 5C, and then depositing a copper plating film inside this opening.

[0056] According to this embodiment, the same effects and advantages as those described in the first embodiment are achieved. In addition, this embodiment achieves the following effects:

[0057] (a) Since the hollow section HP extends to the lower part of the signal conductor pattern 4, the dielectric loss of the high-frequency signal transmission line is reduced more effectively.

[0058] (b) When viewed in the lamination direction of each resin, the interlayer connecting conductors 5V are arranged on both sides of the arrangement line of the hollow portion HP, and the midpoint of the arrangement pitch of the hollow portion HP coincides with the arrangement position of the interlayer connecting conductors 5V, so that the strength of the laminate formed by the lamination of each resin layer is uniformly increased by the interlayer connecting conductors 5V.

[0059] (c) The second resin layers 21 and 22 are more flexible than the first resin layers 11, 12, and 13, so the second resin layers 21 and 22 can absorb the steps of the ground conductor pattern 5C and wrap around the inner surface of the hollow section HP in a stable shape. Incidentally, if the flexibility of each resin layer were equal (if the first resin layers 11, 12, and 13 and the second resin layers 21 and 22 were both soft), it would be difficult to maintain a stable shape of the hollow section HP.

[0060] 《Third Embodiment》 In the third embodiment, an example of a high-frequency signal transmission line in which the shape of the hollow portion HP differs from the examples shown in the first and second embodiments is provided.

[0061] Figure 5 is a cross-sectional view of the high-frequency signal transmission line 103 according to the third embodiment.

[0062] This high-frequency signal transmission line 103 comprises an upper resin laminate 31, a lower resin laminate 32, a signal conductor pattern 4, a first ground conductor layer 51, a second ground conductor layer 52, a ground conductor pattern 5C, and an interlayer connecting conductor (for example, the interlayer connecting conductor 5V shown in Figure 3).

[0063] The upper resin laminated section 31 is the portion where the upper first resin layers 11, 12, 13 and the lower second resin layers 21, 22 are laminated. The lower resin laminated section 32 is the portion where the lower first resin layer 13 and the lower second resin layer 22 are laminated.

[0064] The signal conductor pattern 4 and the ground conductor pattern 5C are formed on the upper surface of the first resin layer 11. The first ground conductor layer 51 is laminated on the upper surface of the upper first resin layer 13. The second ground conductor layer 52 is laminated on the lower surface of the lower first resin layer 13. In other words, the signal conductor pattern 4, the first ground conductor layer 51, and the second ground conductor layer 52 are facing each other with the upper resin laminated section 31 and the lower resin laminated section 32 in between.

[0065] Circular openings are formed in the first resin layers 11, 12 and the second resin layer 21. Represented in the drawing, these openings are circular when viewed in the stacking direction of the first resin layers 11, 12, 13 and the second resin layers 21, 22.

[0066] In the upper resin laminated portion 31, openings are formed in the first resin layers 11 and 12 located along the signal conductor pattern 4, and these openings provide a hollow portion HP around the signal conductor pattern 4.

[0067] The upper part of the second resin layer 22, which is in contact with the first resin layer 12 in which an opening is formed, protrudes into the opening of the first resin layer 12, and in the region of the opening of the first resin layer 12, the thickness T1 of the upper part of the second resin layer 22 is thicker than the thickness T0 of the other regions. Similarly, the lower part of the second resin layer 22, which is in contact with the first resin layer 11 in which an opening is formed, protrudes into the opening of the first resin layer 11, and in the region of the opening of the first resin layer 11, the thickness T1 of the lower part of the second resin layer 22 is thicker than the thickness T0 of the other regions.

[0068] Due to the structure described above, the upper second resin layer 22 is bonded to a portion of the end face (inner end face) at the opening of the first resin layer 12. Similarly, the lower second resin layer 22 is bonded to a portion of the end face (inner end face) at the opening of the first resin layer 11.

[0069] According to this embodiment, similar to the high-frequency signal transmission line shown in the second embodiment, the adhesion strength between the upper second resin layer 22 and the first resin layer 12, and the adhesion strength between the lower second resin layer 22 and the first resin layer 11 are high. Therefore, the strength of the hollow section HP is high, the stress applied to the high-frequency signal transmission line 101 from the outside is mitigated, and damage is prevented. In addition, since the upper and lower second resin layers 22 of the hollow section HP are thick and flat, the strength of the hollow section HP can be easily increased. The cross-sectional shape of this hollow section HP can be changed depending on the flexibility of the second resin layer 22, etc.

[0070] 《Fourth Embodiment》 In the fourth embodiment, we illustrate a high-frequency signal transmission line in which the hollow portion is relatively expanded compared to the embodiments described above.

[0071] Figure 6 is a cross-sectional view of the high-frequency signal transmission line 104 according to the fourth embodiment.

[0072] This high-frequency signal transmission line 104 comprises an upper resin laminate 31, a lower resin laminate 32, a signal conductor pattern 4, a first ground conductor layer 51, a second ground conductor layer 52, and a ground conductor pattern 5C. As shown in the second embodiment, the ground conductor pattern 5C is an intermediate layer ground conductor pattern that is electrically connected to the first ground conductor layer 51 and the second ground conductor layer 52 via an interlayer connecting conductor.

[0073] The differences from the high-frequency signal transmission line 102 shown at the top of Figure 3 are that there is a non-adhesive portion NA between the upper second resin layer 22 and the upper first resin layer 13, and that there is a non-adhesive portion NA between the lower second resin layer 22 and the lower first resin layer 13.

[0074] According to this embodiment, compared to the high-frequency signal transmission line shown in the second embodiment, the air layers above and below the signal conductor pattern 4 can be made thicker, and dielectric loss can be reduced more effectively.

[0075] In the example shown in Figure 6, non-adhesive portions NA are formed on both the top and bottom of the signal conductor pattern 4, but non-adhesive portions NA may be formed on only one of the top or bottom portions.

[0076] The high-frequency signal transmission line 104 of this embodiment is manufactured by the following methods. One method is to apply the upper second resin layer 22 to the upper first resin layer 13, except for the area facing the opening of the first resin layer 12. Similarly, when applying the lower second resin layer 22 to the lower first resin layer 13, except for the area facing the opening of the first resin layer 11. Another method is to apply the upper second resin layer 22 to the entire surface of the upper first resin layer 13, and then partially remove the area near the opening of the first resin layer 12. Similarly, after applying the lower second resin layer 22 to the entire surface of the lower first resin layer 13, partially remove the area near the opening of the first resin layer 11.

[0077] According to this embodiment, the height of the hollow section HP can be easily increased.

[0078] 《Fifth Embodiment》 In the fifth embodiment, a high-frequency signal transmission line is illustrated in which different second resin layers are connected around a hollow portion.

[0079] Figure 7 is a cross-sectional view of the high-frequency signal transmission line 105 according to the fifth embodiment.

[0080] This high-frequency signal transmission line 105 comprises an upper resin laminate 31, a lower resin laminate 32, a signal conductor pattern 4, a first ground conductor layer 51, a second ground conductor layer 52, and a ground conductor pattern 5C. As shown in the second embodiment, the ground conductor pattern 5C is an intermediate layer ground conductor pattern that is electrically connected to the first ground conductor layer 51 and the second ground conductor layer 52 via an interlayer connecting conductor.

[0081] The following two points differentiate this from the high-frequency signal transmission line 102 shown at the top of Figure 3.

[0082] (1) The upper second resin layer 22 and the second resin layer 21 are connected along the hollow section HP.

[0083] (2) The second resin layer 21 and the upper second resin layer 22 are bonded to a part of the end face (inner surface) at the opening of the first resin layer 11.

[0084] According to this embodiment, the adhesive layers, namely the second resin layer 21 and the upper second resin layer 22, are bonded to the entire thickness of the end face (inner surface) at the opening of the first resin layer 12. As a result, the adhesion strength between these second resin layers 21 and 22 and the first resin layer 12 is high. Therefore, the strength of the hollow portion HP is increased more effectively.

[0085] 《Sixth Embodiment》 In the sixth embodiment, an example of a suspended line type high-frequency signal transmission line is shown in which a hollow portion HP exists above the signal conductor pattern 4, and another hollow portion HP exists below the first resin layer 11 on which the signal conductor pattern is formed.

[0086] Figure 8 is a cross-sectional view of the high-frequency signal transmission line 106 according to the sixth embodiment.

[0087] This high-frequency signal transmission line 106 comprises an upper resin laminate 31, a lower resin laminate 32, a signal conductor pattern 4, a first ground conductor layer 51, a second ground conductor layer 52, and a ground conductor pattern 5C.

[0088] The upper resin laminated section 31 is the portion where the upper first resin layers 11, 12, 13 and the second resin layers 21, 22 are laminated. The lower resin laminated section 32 is the portion where the lower first resin layers 12, 13 and the lower second resin layers 22, 23 are laminated. In other words, the resin laminated section consists of the upper resin laminated section 31, which is laminated in the first lamination direction SD1 of the lamination directions of the first and second resin layers, and the lower resin laminated section 32, which is configured in the second lamination direction SD2, which is the opposite direction to the first lamination direction SD1.

[0089] The signal conductor pattern 4 and the ground conductor pattern 5C are formed on the upper surface of the first resin layer 11. The first ground conductor layer 51 is laminated on the upper surface of the upper first resin layer 13. The second ground conductor layer 52 is laminated on the lower surface of the lower first resin layer 13.

[0090] Circular openings are formed in the upper first resin layer 12 and the upper second resin layer 21. Circular openings are also formed in the lower first resin layer 12 and the lower second resin layer 22.

[0091] The other structural features are the same as those of the high-frequency signal transmission line shown in the second embodiment.

[0092] According to this embodiment, since there is a first resin layer 11 that continuously supports the signal conductor pattern 4, the strength of the signal conductor pattern 4 can be easily increased.

[0093] 《Seventh Embodiment》 In the seventh embodiment, an example of a high-frequency signal transmission line is shown in which the shape of the hollow portion HP formed above and below the signal conductor pattern 4 differs from the example shown in the sixth embodiment.

[0094] Figure 9 is a cross-sectional view of the high-frequency signal transmission line 107 according to the seventh embodiment.

[0095] This high-frequency signal transmission line 107 comprises an upper resin laminate 31, a lower resin laminate 32, a signal conductor pattern 4, a first ground conductor layer 51, a second ground conductor layer 52, and a ground conductor pattern 5C.

[0096] The other structural features are the same as those of the high-frequency signal transmission line shown in the sixth embodiment.

[0097] The differences from the high-frequency signal transmission line 106 shown in Figure 8 are as follows:

[0098] (1) The second resin layer 21, which is the adhesive layer on top of the first resin layer 11 on which the signal conductor pattern 4 is formed, is also adhered to a part of the end face (inner surface) at the opening of the upper first resin layer 12. The upper adhesive part SA in Figure 9 represents this location.

[0099] (2) The second resin layers 22 and 23, which are adhesive layers below the first resin layer 11 on which the signal conductor pattern 4 is formed, are also adhered to a portion of the end face (inner surface) at the opening of the lower first resin layer 12. The lower adhesive part SA in Figure 9 represents this location.

[0100] According to this embodiment, since the sides of other first resin layers adjacent to the first resin layer on which the signal conductor pattern 4 is formed are also bonded with the second resin layer, the strength of the hollow portion HP is high, stress applied to the high-frequency signal transmission line 107 from the outside is reduced, and damage is prevented.

[0101] 《Eighth Embodiment》 In the eighth embodiment, a high-frequency signal transmission line is provided as an example in which a hollow portion is formed in the direction of extension of the signal conductor pattern 4.

[0102] The upper part of Figure 10 is a plan view of the high-frequency signal transmission line 108 according to the eighth embodiment, and the lower part of Figure 10 is a longitudinal cross-sectional view of the dashed-dotted line portion in the upper part of Figure 10.

[0103] This high-frequency signal transmission line 108 comprises an upper resin laminate 31, a lower resin laminate 32, a signal conductor pattern 4, a first ground conductor layer 51, a second ground conductor layer 52, a ground conductor pattern 5C, and an interlayer connecting conductor 5V.

[0104] The upper resin laminated section 31 is the portion where the upper first resin layers 11, 12, 13 and the lower second resin layers 21, 22 are laminated. The lower resin laminated section 32 is the portion where the lower first resin layer 13 and the lower second resin layer 22 are laminated.

[0105] The signal conductor pattern 4 and the ground conductor pattern 5C are formed on the upper surface of the first resin layer 11. The first ground conductor layer 51 is laminated on the upper surface of the upper first resin layer 13. The second ground conductor layer 52 is laminated on the lower surface of the lower first resin layer 13. In other words, the signal conductor pattern 4, the first ground conductor layer 51, and the second ground conductor layer 52 are facing each other with the upper resin laminated section 31 and the lower resin laminated section 32 in between.

[0106] Interlayer connecting conductors 5V are formed in the upper resin laminate 31. These interlayer connecting conductors 5V electrically connect the first ground conductor layer 51 and the ground conductor pattern 5C. Interlayer connecting conductors 5V are also formed in the lower resin laminate 32. These interlayer connecting conductors 5V electrically connect the second ground conductor layer 52 and the ground conductor pattern 5C.

[0107] As shown in the upper part of Figure 10, this high-frequency signal transmission line 10 does not have multiple hollow sections HP as shown in the upper part of Figure 1, for example, but rather has a continuous hollow section HP along the extension direction of the signal conductor pattern 4. This high-frequency signal transmission line 108 functions as a strip line consisting of the signal conductor pattern 4, the first ground conductor layer 51, the second ground conductor layer 52, the first resin layer, the second resin layer, and the hollow section HP.

[0108] According to this embodiment, since the hollow portion HP is formed only in the upper resin layer, the mechanical strength of the signal conductor pattern 4 can be easily maintained even if stress is applied near the hollow portion HP due to external forces on the high-frequency signal transmission line 108. Furthermore, since the hollow portion HP is not dispersed in the signal propagation direction, no periodic changes in characteristic impedance occur.

[0109] 《Ninth Embodiment》 In the ninth embodiment, we illustrate a high-frequency signal transmission line in which the positional relationship between the hollow portion and the interlayer connecting conductor and the structure of the interlayer connecting conductor differ from the examples shown so far.

[0110] The upper part of Figure 11 is a plan view of the high-frequency signal transmission line 109 according to the ninth embodiment, and the lower part of Figure 11 is a longitudinal cross-sectional view of the dashed-dotted line portion in the upper part of Figure 11.

[0111] This high-frequency signal transmission line 109 comprises an upper resin laminate 31, a lower resin laminate 32, a signal conductor pattern 4, a first ground conductor layer 51, a second ground conductor layer 52, a ground conductor pattern 5C, and an interlayer connecting conductor 5V.

[0112] In the high-frequency signal transmission line 102 shown at the bottom of Figure 3, interlayer connecting conductors 5V are formed by forming a conductive plating film on the inner surface of openings formed in each resin layer between the first ground conductor layer 51 and the ground conductor pattern 5C, and similarly, interlayer connecting conductors 5V are formed by forming a conductive plating film on the inner surface of openings formed in each resin layer between the second ground conductor layer 52 and the ground conductor pattern 5C. However, in the high-frequency signal transmission line 109 shown in Figure 11, interlayer connecting conductors 5V are formed by filling the openings formed in each resin layer between the first ground conductor layer 51 and the ground conductor pattern 5C with a conductor, and interlayer connecting conductors 5V are formed by filling the openings formed in each resin layer between the second ground conductor layer 52 and the ground conductor pattern 5C with a conductor.

[0113] Figure 2 shows an example where, viewed in the lamination direction of each resin, the interlayer connecting conductors 5V are arranged on both sides of the arrangement line of the hollow portion HP, and the midpoint of the arrangement pitch of the hollow portion HP coincides with the arrangement position of the interlayer connecting conductors 5V. In contrast, in the high-frequency signal transmission line 109 shown in Figure 11, the interlayer connecting conductors 5V are placed on both sides of the hollow portion HP when viewed in the lamination direction of each resin.

[0114] According to this embodiment, since interlayer connecting conductors 5V are located in close proximity to each hollow section HP, the strength of the hollow section HP is effectively increased by the interlayer connecting conductors 5V. That is, when viewed in the lamination direction of the resin layers, the interlayer connecting conductors 5V that are close to the hollow section HP are located in positions that straddle the hollow section HP, so the interlayer connecting conductors 5V are located in close proximity to the hollow section HP. As a result, the strength of the hollow section HP is effectively increased by the interlayer connecting conductors 5V.

[0115] Furthermore, because the interlayer connecting conductor 5V protrudes to the surface and is positioned to straddle the hollow section, even if an external object comes into contact with it, the object will hit the protruding part of the interlayer connecting conductor 5V, preventing it from hitting the top or bottom of the hollow section HP, thereby suppressing deformation of the hollow section HP.

[0116] Furthermore, the structure in which interlayer connecting conductors 5V adjacent to the hollow section HP are positioned to straddle the hollow section HP is also satisfied in the example shown in Figure 2. In other words, in Figure 2, interlayer connecting conductors 5V adjacent to the hollow section HP straddle the hollow section HP along a line inclined at 45 degrees with respect to the arrangement direction of the hollow section HP.

[0117] 《Tenth Embodiment》 In the tenth embodiment, we illustrate a high-frequency signal transmission line in which the positional relationship between the hollow portion and the interlayer connecting conductor and the structure of the interlayer connecting conductor differ from the examples shown so far.

[0118] Figure 12 is a plan view of the high-frequency signal transmission lines 110A and 110B according to the tenth embodiment. Both the high-frequency signal transmission lines 110A and 110B include a first ground conductor layer 51, a ground conductor pattern 51C, signal conductor pattern terminals 4T, a plurality of hollow sections HP, and a plurality of interlayer connecting conductors 5V. The internal structure is as shown in the second embodiment. In the plan view, the second ground conductor layer 52 overlaps with the first ground conductor layer 51.

[0119] The arrangement of the interlayer connecting conductor 5V differs between high-frequency signal transmission line 110A and high-frequency signal transmission line 110B. Both high-frequency signal transmission lines 110A and 110B have fewer conductors than the examples shown in Figures 2 and 111.

[0120] In the high-frequency signal transmission line 110A, in the plan view, adjacent interlayer connecting conductors 5V that are positioned on either side of a hollow section HP pass through (straddle) one hollow section HP.

[0121] In the high-frequency signal transmission line 110B, in the plan view, adjacent interlayer connecting conductors 5V that are positioned on either side of the hollow section HP pass through (straddle) two hollow sections HP.

[0122] Even if the number of such interlayer connecting conductors 5V is small, if adjacent interlayer connecting conductors 5V pass through (straddle) the hollow section HP in a plan view, the degree of reinforcement of the hollow section HP by the interlayer connecting conductors 5V is high, the stress applied to the high-frequency signal transmission lines 110A and 110B from the outside is reduced, and damage is prevented.

[0123] 《Embodiment 11》 In the eleventh embodiment, we illustrate a high-frequency signal transmission line in which the shape and arrangement pitch of the hollow portion differ from those shown in the examples above.

[0124] Figure 13(1) is a plan view of the first resin layer 11 of a high-frequency signal transmission line as an example. For example, it is a plan view of the first resin layer 11 of the high-frequency signal transmission line 102 shown in the second embodiment. Figures 13(2) and (3) are plan views of the first resin layer 11 (the first resin layer on which the signal conductor pattern 4 is formed) of a high-frequency signal transmission line in which the shape of the hollow portion and the arrangement pitch of those portions differ from the example in (1). Figure 13(4) is a plan view of the first resin layer 11 of a high-frequency signal transmission line in which the line width of the signal conductor pattern differs between the hollow portion and the other portions.

[0125] In the example shown in Figure 13 (1), multiple circular openings OH are formed in the first resin layer 11. The width of these openings OH is AW, and the spacing between the openings OH is GS. Here, the larger the value of AW / GS, the higher the rate at which the signal conductor pattern 4 passes through the hollow portion, thereby reducing the dielectric loss due to the relative permittivity and dielectric loss tangent of the resin layer. However, if the value of AW / GS becomes extremely large, the strength of the hollow portion due to the openings OH will be lower than the specified value, and there is a risk of damage near the hollow portion.

[0126] In particular, when the spacing GS becomes smaller, there is a risk that the AW / GS value will become extremely large due to the shortening of the spacing GS caused by manufacturing stacking misalignment.

[0127] In the example shown in Figure 13 (2), oval-shaped openings OH are formed in the first resin layer 11. The width of these openings OH is AW, and the spacing between the openings OH is GS. Thus, even if the shape of the openings OH has an aspect ratio, the larger the AW / GS value, the higher the rate at which the signal conductor pattern 4 passes through the hollow portion, thereby reducing dielectric loss due to the relative permittivity and dielectric loss tangent of the resin layer. However, because the long axis of the openings OH is aligned with the extension direction of the signal conductor pattern 4, the efficiency of lengthening the openings OH relative to the expansion of the planar area of ​​the openings OH is high. Therefore, dielectric loss can be effectively reduced without making the AW / GS value extremely large, the strength of the hollow portion due to the openings OH can be maintained, and the risk of damage near the hollow portion can be reduced.

[0128] In this way, by lengthening the opening OH, the spacing GS can be lengthened, thus maintaining the strength of the hollow section. For example, in the example shown at the top of Figure 13, if AW = 4 mm and GS = 1 mm, then in the example shown in the middle of Figure 13, by setting AW = 7 mm and GS = 1.75 mm, the effect of creating a hollow section with the opening OH can be made equivalent.

[0129] In the example shown in Figure 13 (3), an opening OH is formed in the first resin layer 11 in the shape of two circles overlapping and offset by a certain distance in the direction of extension of the signal conductor pattern 4. The width of these openings OH in the direction of extension of the signal conductor pattern 4 is AW, and the spacing between the openings OH is GS. Even in this case of opening OH shape, the long axis of the opening OH is aligned with the direction of extension of the signal conductor pattern 4, resulting in a high efficiency in lengthening the opening OH relative to the expansion of the planar area of ​​the opening OH. Moreover, the efficiency in lengthening the opening OH relative to the expansion of the planar area of ​​the opening OH is even higher compared to the example in Figure 13 (2). Therefore, the rate of expansion of the planar area that occurs when the value of AW / GS increases is suppressed. As a result, the strength of the hollow part due to the opening OH can be maintained, and the risk of damage near the hollow part can be further reduced.

[0130] In the example shown in Figure 13 (4), the line width of the signal conductor pattern 4 differs between the portion laminated on the second resin layer (second resin layer 21 shown in Figure 3) and the portion not in contact with the second resin layer. The line width of the signal conductor pattern 4 not in contact with the second resin layer is thicker than the line width of the signal conductor pattern 4 laminated on the second resin layer. This structure makes it possible to match the relative permittivity between the signal conductor pattern 4 and the first ground layer (first ground conductor layer 51 shown in Figure 3) and the second ground conductor layer (second ground conductor layer 52 shown in Figure 3), thereby suppressing unwanted reflections due to characteristic impedance mismatch in high-frequency signals.

[0131] The upper part of Figure 14 is a plan view of the first resin layer 11 of an example high-frequency signal transmission line. The lower part of Figure 14 is a plan view of the first resin layer 11 (the first resin layer on which the signal conductor pattern 4 is formed) of a high-frequency signal transmission line that differs from the upper example in the shape of the hollow sections and their arrangement pitch.

[0132] In the example shown at the top of Figure 14, multiple rhombus-shaped openings OH, each with rounded corners, are formed in the first resin layer 11. The width of these openings OH in the direction of extension of the signal conductor pattern 4 is AW, and the spacing between the openings OH in the direction of extension of the signal conductor pattern 4 is GS. As described above, the larger the value of AW / GS, the higher the rate at which the signal conductor pattern 4 passes through the hollow portion, thereby reducing dielectric loss due to the relative permittivity and dielectric loss tangent of the resin layer.

[0133] Comparing the example shown at the top of Figure 14 with the example shown at the top of Figure 13, even if the AW / GS values ​​are the same, the planar area and volume of the opening OH can be reduced. This enhances the effect of maintaining the strength of the hollow section due to the opening OH and further reducing the risk of damage near the hollow section.

[0134] In the example shown at the bottom of Figure 14, an opening OH is formed in the first resin layer 11 in the shape of three rhombuses overlapping and offset by a certain distance in the direction of extension of the signal conductor pattern 4. The width of these openings OH in the direction of extension of the signal conductor pattern 4 is AW, and the spacing between the openings OH is GS. In the case of openings OH of this shape, as with the example shown in (3) of Figure 13, the long axis of the opening OH is aligned with the direction of extension of the signal conductor pattern 4, resulting in a high efficiency in lengthening the opening OH relative to the expansion of the planar area of ​​the opening OH.

[0135] 《Twelfth Embodiment》 In the twelfth embodiment, a high-frequency signal transmission line in which the top and bottom of the resin laminate are recessed is illustrated.

[0136] The upper part of Figure 15 is a cross-sectional view of the high-frequency signal transmission line 112 according to this embodiment. The lower part of Figure 15 is a cross-sectional view of the high-frequency signal transmission line 112 showing the electric field distribution by electric field lines. This high-frequency signal transmission line 112 comprises an upper resin laminate 31, a lower resin laminate 32, a signal conductor pattern 4, a first ground conductor layer 51, a second ground conductor layer 52, and a ground conductor pattern 5C. The other basic structure is the same as that of the high-frequency signal transmission line 109 shown in Figure 11.

[0137] Unlike the example shown in Figure 3, in the high-frequency signal transmission line 112 of this embodiment, recesses RA are formed in the hollow portion HP, with the top and bottom indented in the resin lamination direction. During manufacturing, the recesses RA are formed in the high-frequency signal transmission line 112 by press processing with the first ground conductor layer 51 attached to the first resin layer 13.

[0138] The high-frequency signal transmission line 112 of this embodiment provides the following effects.

[0139] (a) It becomes difficult for any object to strike the vicinity of the hollow section HP from outside the high-frequency signal transmission line 112, thereby preventing deformation of the hollow section HP and its surroundings.

[0140] (b) Because the resin layer near the hollow HP has an arched cross-section, deformation of the hollow HP and its surroundings can be effectively suppressed.

[0141] Needless to say, in this embodiment as well, interlayer connecting conductors protruding to the outside of the resin laminate may exist, as shown in Figure 3.

[0142] In the high-frequency signal transmission line 112 of this embodiment, the arrows drawn in the lower part of Figure 15, extending from the signal conductor pattern 4, are noteworthy electric field lines. In this way, electric fields are generated between the signal conductor pattern 4 and the first ground conductor layer 51, and between the signal conductor pattern 4 and the second ground conductor layer 52. As shown in this figure, the closer to both ends of the signal conductor pattern 4, that is, the further away from the center of the signal conductor pattern 4, the longer the electric field lines from the signal conductor pattern 4 to the first ground conductor layer 51 and the second ground conductor layer 52 become.

[0143] The signal conductor pattern 4 exhibits a higher current density closer to its ends due to the edge effect (skin effect). However, with the above configuration, the electric field strength is suppressed closer to the ends of the signal conductor pattern 4, thus averaging the current distribution in the signal conductor pattern 4. As a result, conductor losses due to the signal conductor pattern 4 are mitigated.

[0144] 《13th Embodiment》 In the 13th embodiment, a high-frequency signal transmission line having a protective film on its outer surface is illustrated.

[0145] Figure 16 is a longitudinal cross-sectional view of a high-frequency signal transmission line 113A constructed by forming a resist film on the high-frequency signal transmission line 109 shown in Figure 11.

[0146] Figure 17 is a longitudinal cross-sectional view of a high-frequency signal transmission line 113B constructed by forming a resist film on the high-frequency signal transmission line 109 shown in Figure 11.

[0147] The resist film RF shown in Figures 16 and 17 is a resist film obtained by applying resist resin to both sides of the high-frequency signal transmission line 109 shown in Figure 11 and then curing it.

[0148] In this way, by providing a resist film RF on the outer surface, the stress applied to the high-frequency signal transmission lines 113A and 113B from the outside is relieved by the resist film RF, and the decrease in strength of the high-frequency signal transmission lines due to the presence of the hollow portion HP is further suppressed.

[0149] In the high-frequency signal transmission line 113A shown in Figure 16, even if some object comes into contact with it from the outside, the stress received by the resist film RF is concentrated on the interlayer connecting conductor 5V, thus protecting the hollow portion HP.

[0150] As shown in Figure 17, if the resist film RF protrudes at the protruding portion of the interlayer connecting conductor 5V, the presence of these protrusions makes it difficult for any object to strike the vicinity of the hollow portion HP from outside the high-frequency signal transmission line 113B, thereby preventing deformation of the hollow portion HP and its surroundings.

[0151] 《Embodiment 14》 In the 14th embodiment, we illustrate a high-frequency signal transmission line in which the structure of the upper and lower outer surfaces of the hollow portion differs from the examples shown so far.

[0152] Figure 18 is a longitudinal cross-sectional view of a high-frequency signal transmission line 114 according to the 14th embodiment. In this example, when viewed in the stacking direction of each layer, the plating thickness of the region overlapping the hollow portion HP of the first ground conductor layer 51 and the second ground conductor layer 52 is increased to form a thickened portion TF. The plating of this region may be performed simultaneously with the plating for forming the interlayer connecting conductor 5V.

[0153] According to this embodiment, the strength of the hollow portion HP in the laminate is effectively increased both above and below. This allows for more effective suppression of deformation of the hollow portion HP.

[0154] 《Embodiment 15》 In the 15th embodiment, an example of an electronic device is provided.

[0155] The high-frequency signal transmission line of the present invention can be used as a high-frequency signal transmission line in various electronic devices. For example, connectors are provided on high-frequency circuits formed on two circuit boards, and the coaxial connectors 61 and 62 of the high-frequency signal transmission line 101 shown in Figure 1 are connected to each other. The circuit boards and the high-frequency signal transmission line 101 are housed in a housing of a predetermined shape. The electronic device is configured in this way.

[0156] Finally, the present invention is not limited to the embodiments described above. It can be appropriately modified and altered by those skilled in the art. The scope of the present invention is defined by the claims, not by the embodiments described above. Furthermore, the scope of the present invention includes modifications and alterations from the claims and equivalent embodiments.

[0157] For example, although each embodiment shows a high-frequency signal transmission line having a single signal conductor pattern, it may have multiple signal conductor patterns.

[0158] Furthermore, a differential line may be configured with two or more signal conductor patterns. This configuration can also be applied to a configuration in which multiple signal conductor patterns constituting this differential line are arranged within a single hollow section.

[0159] Furthermore, the multiple signal conductor patterns may be arranged in the layer direction of each resin layer, or in the stacking direction of each resin layer.

[0160] Furthermore, although each embodiment shows a rectangular high-frequency signal transmission line viewed from the lamination direction of each resin layer, this shape is arbitrary.

[0161] Furthermore, although each embodiment shows a high-frequency signal transmission line having a linear signal conductor pattern, the signal conductor pattern may be curved or partially curved when viewed from the lamination direction of each resin layer.

[0162] Furthermore, although planar high-frequency signal transmission lines are shown in each embodiment, the lamination surface of each resin layer may be a curved surface such as a cylindrical surface, or a partially curved surface. In addition, for example, the whole or part may be a twisted curved surface.

[0163] Furthermore, in order to bond the copper foil forming the ground conductor layer to the first resin layer, another resin layer different from the first and second resin layers may be provided.

[0164] The high-frequency signal transmission line and electronic equipment of the present invention may be provided in the following embodiments.

[0165] <1> The device comprises a resin laminate formed by laminating one or more first resin layers and one or more second resin layers, a signal conductor pattern arranged to be in contact with at least one of the first resin layers, and a ground conductor layer facing the signal conductor pattern with part or all of the resin laminate in between. In the resin laminate, an opening is formed in at least one of the first resin layers located along the signal conductor pattern, thereby providing a hollow portion in the resin laminate at the opening. The second resin layer in contact with the first resin layer in which the opening is formed is bonded to a part of the end face of the opening in the first resin layer. High-frequency signal transmission line.

[0166] <2> The ground conductor layer is composed of a first ground layer and a second ground conductor layer located on both sides of the signal conductor pattern in the direction of lamination. The first resin layer and the second resin layer are located on both sides of the signal conductor pattern in the lamination direction, <1> A high-frequency signal transmission line as described above.

[0167] <3> The interlayer connecting conductor electrically connects the first ground conductor layer and the second ground conductor layer, The transmission line is formed by the first ground conductor layer, the second ground conductor layer, the upper resin laminate, the lower resin laminate, the signal conductor pattern, and the interlayer connecting conductor. <2> A high-frequency signal transmission line as described above.

[0168] <4> The interlayer connecting conductor has a projection that protrudes outward from the first ground conductor layer in the first stacking direction, and the interlayer connecting conductor has a projection that protrudes outward from the second ground conductor layer in the second stacking direction. <3> A high-frequency signal transmission line as described above.

[0169] <5> The outer surface of the upper resin laminate or the lower resin laminate is provided with a third resin layer that covers the protruding portion of the interlayer connecting conductor. <4> A high-frequency signal transmission line as described above.

[0170] <6> The second resin layer in contact with the first resin layer in which the opening is formed has a difference in its maximum and minimum thickness at the opening in the first resin layer, so that the second resin layer in contact with the first resin layer adheres to a part of the end face at the opening in the first resin layer. <1> from <5> A high-frequency signal transmission line as described in any of the following.

[0171] <7> The portion of the second resin layer that forms part of the hollow section is a curved surface that extends outward from the hollow section near the center compared to the periphery of the hollow section. <1> from <6> A high-frequency signal transmission line as described in any of the following.

[0172] <8> At room temperature, the second resin layer is more flexible than the first resin layer. <1> from <7> A high-frequency signal transmission line as described in any of the following.

[0173] <9> The resin material of the second resin layer has a lower dielectric constant and lower dielectric loss tangent compared to the resin material of the first resin layer. <1> from <8> A high-frequency signal transmission line as described in any of the following.

[0174] <10> In the opening of the first resin layer, a portion of the second resin layer is formed in an arch shape. <1> from <9> A high-frequency signal transmission line as described in any of the following.

[0175] <11> The second resin layer, which is in contact with the first resin layer in which the opening is formed, protrudes into the opening, and the thickness of the second resin layer is thicker in the region of the opening than in other regions. <1> from <10> A high-frequency signal transmission line as described in any of the following.

[0176] <12> The opening of the first resin layer is formed in the opening of the second resin layer, and the opening of the first resin layer and the opening of the second resin layer form the hollow portion. <1> from <11> A high-frequency signal transmission line as described in any of the following.

[0177] <13> The hollow portion is formed over a wider area than the width of the signal conductor pattern. <1> from <12> A high-frequency signal transmission line as described in any of the following.

[0178] <14> <1> from <13> Electronic equipment comprising a high-frequency signal transmission line as described in any of the following. [Explanation of Symbols]

[0179] FA...Adhesive part GS...interval HP…Hollow part NA…Non-adhesive area OH...Opening RA…recess RF...resist film SA...adhesive part SD1…First stacking direction SD2…Second stacking direction TF…Thickened part T0…Normal thickness T1...Expansion thickness 3…Resin laminated section 4…Signal conductor pattern 4T…Signal conductor pattern terminal 5…Ground conductor layer 5C...Ground conductor pattern 5V...Interlayer connecting conductor 10…High-frequency signal transmission line 11,12,13...first resin layer 21,22,23…Second resin layer 31…Upper resin laminated section 32...Lower resin laminated section 51…First ground conductor layer 51C...Ground conductor pattern 52...Second ground conductor layer 61, 62… Coaxial connectors 101-109... High-frequency signal transmission lines 110A, 110B… High-frequency signal transmission lines 112... High-frequency signal transmission line 113A, 113B… High-frequency signal transmission lines

Claims

1. The device comprises a resin laminate formed by laminating one or more first resin layers and one or more second resin layers, a signal conductor pattern arranged to be in contact with at least one of the first resin layers, and a ground conductor layer facing the signal conductor pattern with part or all of the resin laminate in between. In the resin laminate, an opening is formed in at least one of the first resin layers located along the signal conductor pattern, thereby providing a hollow portion in the resin laminate at the opening. The second resin layer in contact with the first resin layer in which the opening is formed is bonded to a part of the end face of the opening in the first resin layer. High-frequency signal transmission line.

2. The ground conductor layer is composed of a first ground conductor layer and a second ground conductor layer located on both sides of the signal conductor pattern in the direction of lamination. The resin laminate portion exists as an upper resin laminate portion and a lower resin laminate portion on both sides of the signal conductor pattern in the direction of lamination. The high-frequency signal transmission line according to claim 1.

3. The first ground conductor layer and the second ground conductor layer are electrically connected by interlayer connecting conductors, The transmission line is formed by the first ground conductor layer, the second ground conductor layer, the upper resin laminate, the lower resin laminate, the signal conductor pattern, and the interlayer connecting conductor. The high-frequency signal transmission line according to claim 2.

4. The interlayer connecting conductor has a protrusion that extends outward from the first ground conductor layer, and the interlayer connecting conductor has a protrusion that extends outward from the second ground conductor layer. The high-frequency signal transmission line according to claim 3.

5. The outer surface of the upper resin laminate or the lower resin laminate is provided with a third resin layer that covers the protruding portion of the interlayer connecting conductor. The high-frequency signal transmission line according to claim 4.

6. The second resin layer in contact with the first resin layer in which the opening is formed has a difference in maximum and minimum thickness at the opening in the first resin layer, so that the second resin layer in contact with the first resin layer adheres to a part of the end face at the opening in the first resin layer. A high-frequency signal transmission line according to any one of claims 1 to 5.

7. The portion of the second resin layer that forms part of the hollow section is a curved surface that extends outward from the hollow section near the center compared to the periphery of the hollow section. A high-frequency signal transmission line according to any one of claims 1 to 5.

8. At room temperature, the second resin layer has a lower Young's modulus than the first resin layer. A high-frequency signal transmission line according to any one of claims 1 to 5.

9. The resin material of the second resin layer has a lower dielectric constant and lower dielectric loss tangent compared to the resin material of the first resin layer. A high-frequency signal transmission line according to any one of claims 1 to 5.

10. In the opening of the first resin layer, a part of the second resin layer is formed in an arch shape. A high-frequency signal transmission line according to any one of claims 1 to 5.

11. The second resin layer, which is in contact with the first resin layer in which the opening is formed, protrudes into the opening, and the thickness of the second resin layer is thicker in the region of the opening than in other regions. A high-frequency signal transmission line according to any one of claims 1 to 5.

12. The opening of the first resin layer is formed in the opening of the second resin layer, and the opening of the first resin layer and the opening of the second resin layer form the hollow portion. A high-frequency signal transmission line according to any one of claims 1 to 5.

13. The hollow portion is formed over a wider area than the width of the signal conductor pattern. A high-frequency signal transmission line according to any one of claims 1 to 5.

14. An electronic device comprising a high-frequency signal transmission line according to any one of claims 1 to 5.

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