Signal line, wiring board, package for housing electronic component, and electronic device

Abstract

This signal line comprises: a microstrip line that has a second signal conductor and a third ground conductor facing the second signal conductor, and is connected to a coplanar line; a fourth ground conductor positioned at a side of the second signal conductor and on a side of a connection portion between the microstrip line and the coplanar line in a plan view; and a plurality of second via conductors positioned so as to bridge the fourth ground conductor and the third ground conductor. When a distance between the second signal conductor and the third ground conductor is referred to as a first distance, a longitudinal direction of the second signal conductor is referred to as a Y direction, and a direction orthogonal to the Y direction in the plan view is referred to as an X direction, there is a gap between the second signal conductor and the fourth ground conductor, the gap having a width in the X direction of 90% or more of the first distance.

Description

Signal line, wiring board, package for housing electronic components, and electronic device

[0001] The present disclosure relates to a signal line, a wiring board, a package for housing electronic components, and an electronic device.

[0002] Japanese Patent Application Laid-Open No. 2001-345607 describes a line converter having a connection portion that allows a transmission mode of a coplanar line and a transmission mode of a microstrip line to coexist.

[0003] The signal line according to the present disclosure includes: a substrate that is a dielectric and has a first surface; a first signal conductor located on the first surface; a pair of first ground conductors located on the first surface with the first signal conductor interposed therebetween; a second ground conductor located in the substrate and facing the first signal conductor and the pair of first ground conductors; a plurality of first via conductors located across between the pair of first ground conductors and the second ground conductor, which constitute a coplanar line; a second signal conductor located on the first surface; and a third ground conductor located in the substrate and facing the second signal conductor, which constitute a microstrip line connected to the coplanar line; a fourth ground conductor located on a side portion of the second signal conductor in a plan view and on a side of a connection portion between the microstrip line and the coplanar line; and a plurality of second via conductors located across between the fourth ground conductor and the third ground conductor. When the distance between the second signal conductor and the third ground conductor is referred to as a first distance, the longitudinal direction of the second signal conductor is referred to as the Y direction, and the direction orthogonal to the Y direction in a plan view is referred to as the X direction, there is a gap having a width of 90% or more of the first distance in the X direction between the second signal conductor and the fourth ground conductor.

[0004] The wiring board according to the present disclosure includes the above-described signal line.

[0005] The package for housing electronic components according to the present disclosure includes the above-described signal line.

[0006] The electronic device according to the present disclosure includes the above-described package for housing electronic components and an electronic component housed in the package for housing electronic components.

[0007] This is a perspective view showing the signal line and wiring board of Embodiment 1 of the present disclosure. This is a side view showing the signal line and wiring board of Embodiment 1 of the present disclosure. This is a graph showing the frequency characteristics of the signal line of Embodiment 1 and the signal line of the comparative example. This is a perspective view showing the signal line of Comparative Example 1 in Figure 2. This is a perspective view showing the signal line of Comparative Example 2 in Figure 2. This is a perspective view showing the signal line of Comparative Example 3 in Figure 2. This is a perspective view showing the signal line of Comparative Example 4 in Figure 2. This is a plan view explaining each parameter of the signal line of Embodiment 1 used in the simulation. This is a side view explaining each parameter of the signal line of Embodiment 1 used in the simulation. This is a plan view showing the main part of the signal line of Embodiment 2 of the present disclosure. This is a longitudinal cross-sectional view showing the main part of the signal line of Embodiment 3 of the present disclosure. This is a graph showing the frequency characteristics of the signal lines of Embodiments 2 and 3. This is a longitudinal cross-sectional view showing the main part of the signal line of Embodiment 4 of the present disclosure. This is a longitudinal cross-sectional view showing the main part of the signal line of Embodiment 5 of the present disclosure. This is a longitudinal cross-sectional view showing the main part of the signal line of Embodiment 6 of the present disclosure. This is a graph showing the frequency characteristics of the signal lines of Embodiments 4 to 6. This is a graph showing the frequency characteristics of the signal line of Embodiment 4 with a different position for the fourth ground conductor. This is a diagram of the signal line of Comparative Example 5. This is a diagram of the signal line of Comparative Example 6. This is a graph showing the frequency characteristics of the signal lines of Comparative Examples 5 and 6. This is a graph showing the relationship between the width of the gap between the fourth ground conductor and the second signal conductor and the loss at a specific frequency. This is a graph showing the relationship between the width of the gap between the fourth ground conductor and the second signal conductor and the frequency at which the first loss occurs. This is a graph showing the relationship between the length of the fourth ground conductor and the loss at a specific frequency. This is a graph showing the relationship between the length of the fourth ground conductor and the frequency at which the first loss occurs. This is a perspective view showing the signal line of Embodiment 7 of this disclosure. This is a perspective view showing the signal line of Embodiment 8 of this disclosure. This is a perspective view showing the signal line of Embodiment 9 of this disclosure. This is a graph showing the frequency characteristics of the signal lines of Embodiments 7 to 9. This is a plan view showing the main part of the signal line of Embodiment 10 of this disclosure. This is a plan view showing the main part of the signal line of Embodiment 11 of this disclosure. This is a plan view showing the main part of the signal line of Embodiment 12 of this disclosure. This is a plan view showing the main part of the signal line according to Embodiment 13 of this disclosure. This is a plan view showing the main part of the signal line according to Embodiment 14 of this disclosure. This is a plan view showing the main part of the signal line according to Embodiment 15 of this disclosure.This is a plan view showing the main part of the signal line of Embodiment 16 of the present disclosure. This is a graph showing the frequency characteristics of the signal lines of Embodiments 13 to 16. This is a perspective view showing the signal line of Embodiment 17 of the present disclosure. This is a perspective view showing the signal line of Embodiment 18 of the present disclosure. This is a perspective view showing the signal line of Embodiment 19 of the present disclosure. This is a graph showing the frequency characteristics of the signal lines of Embodiments 17 to 19 and Comparative Example 7. This is a longitudinal cross-sectional view showing an electronic component housing package and electronic device according to an embodiment of the present disclosure. This is a plan view showing an electronic component housing package and electronic device according to an embodiment of the present disclosure.

[0008] Each embodiment of this disclosure will be described in detail below with reference to the drawings. In this specification, "plan view" means viewing from a direction perpendicular to the first surface S1 of the substrate 11. "Plan view" means viewing from a direction perpendicular to the first surface S1 of the substrate 11, and is a concept that encompasses the plan view. Furthermore, the longitudinal direction of the first signal conductor 21 and the longitudinal direction of the second signal conductor 31 will be referred to as the "Y direction," the direction orthogonal to the first surface S1 will be referred to as the "Z direction," and the direction orthogonal to the Y direction in the plan view will be referred to as the "X direction." Furthermore, "target transmission signal" means the transmission signal with the highest frequency in the usage band, and the effective wavelength of the transmission signal will be denoted as λeff. In this embodiment, it is assumed that the usage band is 130 GHz to 170 GHz, or a higher 130 GHz to 190 GHz, and a 190 GHz transmission signal is adopted as the "target transmission signal." Furthermore, in the embodiments described below, a circuit board that is plate-shaped will be used as an example to explain the configuration including the signal lines, but the signal lines according to this disclosure may be included in configurations of various shapes.

[0009] (Embodiment 1) Figures 1A and 1B are a perspective view and a side view, respectively, showing a signal line and a wiring board according to Embodiment 1 of the present disclosure. The signal line 1 and wiring board 100 of Embodiment 1 include a dielectric substrate 11, a coplanar line 2 located on the substrate 11, and a microstrip line 3 located on the substrate 11 and connected to the coplanar line 2.

[0010] The substrate 11 may have a plate-like shape having a first surface S1 and a second surface S2 opposite to the first surface S1. The substrate 11 may be made of, for example, alumina (Al ２O ３ Although it is a ceramic, various dielectric materials may be used. The first surface S1 may be planar. The substrate 11 has a first region 12 where the coplanar line 2 is located and a second region 13 where the microstrip line 3 is located, and in a plan view, the first region 12 and the second region 13 may be aligned in the direction of signal transmission.

[0011] The coplanar line 2 includes a first signal conductor 21 located on a first plane S1, a pair of first ground conductors 22a and 22b located on the first plane S1 with the first signal conductor 21 in between, a second ground conductor 23 located on the base 11, and a plurality of first via conductors 24 located between the pair of first ground conductors 22a and 22b and the second ground conductor 23. The second ground conductor 23 is positioned to face the first signal conductor 21 and the pair of first ground conductors 22a and 22b in the Z direction. The coplanar line 2 may also be called a GCPW (Grounded Coplanar Waveguide).

[0012] The first signal conductor 21 is configured to be long in the signal transmission direction and may be a linear or strip-shaped conductor with width. The pair of first ground conductors 22a and 22b are film-like conductors that extend along the first surface S1 and may be positioned to sandwich the entire longitudinal area of ​​the first signal conductor 21 from both sides with a gap between them. This gap may be equal in size over a range of 80% or more in the Y direction. The second ground conductor 23 may be a film-like conductor that extends in a planar direction parallel to the first surface S1. The second ground conductor 23 may be located on the second surface S2 or inside the base 11. In a planar view, the pitch of the plurality of first via conductors 24 aligned along the first signal conductor 21 may be 1 / 4 or less of the effective wavelength λeff of the target transmission signal.

[0013] The line width of the first signal conductor 21 (i.e., the width in the X direction), the width of the spacing between the first signal conductor 21 and the first ground conductors 22a and 22b, and the distance between the first signal conductor 21 and the second ground conductor 23 may be designed so that the impedance of the coplanar line 2 is a predetermined value in accordance with the frequency of the transmitted signal.

[0014] The microstrip line 3 has a second signal conductor 31 located on the first surface S1 and a third ground conductor 32 located on the base 11 and facing the second signal conductor 31 in the Z direction. The second signal conductor 31 is configured to be long in the signal transmission direction and may be a linear or strip-shaped conductor with width. The third ground conductor 32 may be a film-shaped conductor that spreads planarly in a direction parallel to the first surface S1. The third ground conductor 32 may be located on the second surface S2 or inside the base 11.

[0015] The first distance D1 between the second signal conductor 31 and the third ground conductor 32 in the microstrip line 3 may be designed to match the distance between the first signal conductor 21 and the second ground conductor 23 in the coplanar line. The line width (i.e., width in the X direction) of the second signal conductor 31 may be designed so that the impedance of the microstrip line 3 is a predetermined value in accordance with the frequency of the transmitted signal.

[0016] The signal line 1 may further have a connection portion 4 between the coplanar line 2 and the microstrip line 3. That is, the coplanar line 2 and the microstrip line 3 may be connected via the connection portion 4. The connection portion 4 may have a third signal conductor 41 connected to the first signal conductor 21 and the second signal conductor 31. The third signal conductor 41 may have a reverse taper from the first signal conductor 21 side to the second signal conductor 31 side, where the line width gradually increases from the line width of the first signal conductor 21 to the line width of the second signal conductor 31.

[0017] The second grounding conductor 23 of the coplanar line 2 and the third grounding conductor 32 of the microstrip line 3 may be continuous and integral with each other. Alternatively, at the connection point 4 between the coplanar line 2 and the microstrip line 3, a configuration may be adopted in which the second grounding conductor 23 and the third grounding conductor 32 are electrically connected via conductors at multiple locations.

[0018] <Fourth Grounding Conductor> The signal line 1 may further include a fourth grounding conductor 42 located on the side of the second signal conductor 31 and on the side of the connection portion 4 in a plan view. The side of the second signal conductor 31 means a location near the second signal conductor 31 and away from the second signal conductor 31 in the X direction. Nearby means close enough that the electromagnetic waves of the transmitted signal have at least a slight influence, and the distance may be defined as less than or equal to half the effective wavelength λeff of the target transmitted signal. The side of the connection portion 4 means overlapping with or being close to a region 14 obtained by extending the connection portion 4 in the X direction in a plan view.

[0019] The signal line 1 may further include a plurality of second via conductors 43 located between the fourth ground conductor 42 and the third ground conductor 32. The pitch of the second via conductors 43 may be 1 / 4 or less of the effective wavelength λeff of the target transmission signal.

[0020] When the distance between the second signal conductor 31 and the third ground conductor 32 is expressed as the first distance D1 (see Figure 1B), a gap 51 may be located between the second signal conductor 31 and the fourth ground conductor 42, with a width in the X direction of 90% or more of the first distance D1. In this specification, "gap" means an area occupied by materials other than conductors (e.g., dielectrics and air).

[0021] The fourth grounding conductor 42 may have the shape and arrangement of Embodiment 1 shown in Figure 1A. That is, the fourth grounding conductor 42 may be located on the first surface S1, and its end in the Y direction may be in contact with the first grounding conductors 22a and 22b. Specifically, the fourth grounding conductor 42 may be a film-like conductor integrated with the first grounding conductors 22a and 22b. The signal line 1 may have two fourth grounding conductors 42. In a plan view, the two fourth grounding conductors 42 may be located on one side of the second signaling conductor 31 and the other side, respectively. At least the side of the fourth grounding conductor 42 on the side of the second signaling conductor 31 may extend linearly in the Y direction, and the width of the gap 51 between it and the second signaling conductor 31 may be the same length within a range of 80% or more. Furthermore, the corner E1 of the fourth grounding conductor 42 on the side opposite to the first grounding conductors 22a and 22b in the Y direction (see Figure 1A) may have a rounded shape (specifically, an r-shaped shape).

[0022] <Function of the fourth grounding conductor> The signal line 1 having the fourth grounding conductor 42 and the second via conductor 43 reduces the leakage of electromagnetic waves of the transmission signal at the connection point 4 and improves the signal transmission characteristics up to higher frequency bands through the following actions.

[0023] In other words, generally, electromagnetic waves are transmitted in different modes in the coplanar line 2 and the microstrip line 3. For example, in the microstrip line 3, electromagnetic waves are transmitted in a mode in which electric field lines extend from the second signal conductor 31 to the third ground conductor 32 (hereinafter referred to as the "MSL mode"), while in the coplanar line 2, electromagnetic waves are transmitted in a mode in which electric field lines extending from the first signal conductor 21 to a pair of first ground conductors 22a and 22b are added (hereinafter referred to as the "GCPW mode"). Therefore, at the connection point between the conventional coplanar line and the microstrip line, some of the electromagnetic waves are prone to leaking to the outside as the mode of transmission changes.

[0024] If a grounding conductor is positioned close to the side of a signal conductor in a microstrip line, an electromagnetic wave mode, i.e., a GCPW mode, is induced, in which electric field lines extend from the signal conductor to the side grounding conductor. This induction is stronger when the signal conductor and the side grounding conductor are close together, and weaker when they are far apart.

[0025] Furthermore, a dielectric material occupies the space between the signal conductor of the microstrip line and the lower ground conductor (corresponding to the second signal conductor 31 and the third ground conductor 32 in the embodiment). On the other hand, the lower half of the space to the side of the signal conductor is occupied by the dielectric material, and the upper half is occupied by air. Therefore, when the distance between the signal conductor and the lower ground conductor is expressed as the first distance D1, if the distance between the signal conductor and the side ground conductor is 90% or more of the first distance D1, the induction effect of the above-mentioned GCPW mode becomes very small. Also, even when the side ground conductor is displaced downward from the upper surface of the base, if it is 90% or more of the first distance D1 from the signal conductor in a planar perspective view, the induction effect of the above-mentioned GCPW mode becomes very small.

[0026] For the reasons stated above, the fourth grounding conductor 42 in this embodiment is a side grounding conductor with less induction of the GCPW mode. Furthermore, by positioning the fourth grounding conductor 42 in and near the connection point 4, a portion of the GCPW mode electromagnetic waves that would otherwise leak to the outside at the connection point 4 is blocked by the fourth grounding conductor 42 and the plurality of second via conductors 43, and sent back to the first grounding conductors 22a, 22b or the second grounding conductor 23 that transmit the GCPW mode electromagnetic waves. Therefore, electromagnetic wave leakage at the connection point 4 is suppressed, improving the signal transmission characteristics between the coplanar line 2 and the microstrip line 3 across the connection point 4.

[0027] Here, let's consider the case where the distance between the second signal conductor 31 and the fourth ground conductor 42 is shorter than the first distance D1. In this case, the effect of the fourth ground conductor 42 in inducing GCPW mode electromagnetic waves becomes stronger. Therefore, the section where the fourth ground conductor 42 is located becomes a section of mixed mode between GCPW mode and MSL mode. In this configuration, at the end of the fourth ground conductor 42, the mode of the transmitted electromagnetic waves switches from the above mixed mode to the MSL mode. Therefore, with the switch, some of the electromagnetic waves are more likely to leak to the outside, and the characteristics deteriorate. In other words, electromagnetic wave leakage occurs at the end of the fourth ground conductor 42.

[0028] Therefore, in the signal line 1 of this embodiment, a gap 51 with a width in the X direction of at least the first distance D1 is provided between the second signal conductor 31 and the fourth ground conductor 42 so that the fourth ground conductor 42 does not induce electromagnetic waves in the GCPW mode. The width of this gap 51 greatly contributes to improving the signal transmission characteristics.

[0029] <Transmission Characteristics> Figure 2 is a graph showing the frequency characteristics of signal line 1 of Embodiment 1 and signal lines 80A to 80D of Comparative Examples 1 to 4. The characteristic curve in the graph of Figure 2 was calculated by simulation, and the vertical axis shows the insertion loss. A value close to 0 dB indicates low loss, and a negative value with a large absolute value indicates high loss. The same applies to the graphs in Figures 7, 9, 10, 12, 18, 21, and 23 below. Figures 3A to 3D are perspective views showing signal lines 80A to 80D of Comparative Examples 1 to 4 in Figure 2, respectively. Figures 4A and 4B are plan and side views illustrating the parameters of signal line 1 of Embodiment 1 used in the simulation.

[0030] The signal line 80A of Comparative Example 1 consists only of a coplanar line 82. The signal line 80B of Comparative Example 2 consists only of a microstrip line 83. The signal line 80C of Comparative Example 3 is configured in which the coplanar line 82 and the microstrip line 83 are connected at a connection section 84. At the connection section 84, there is a signal conductor 841 having a reverse taper shape that matches the line width of the preceding and succeeding signal conductors 821 and 831. The signal line 80D of Comparative Example 4 has a connection section 84D between the coplanar line 82 and the microstrip line 83 that realizes a transmission section in a mixed mode of GCPW mode and MSL mode. In the mixed mode transmission section, ground conductors 843a and 843b are located on the side of the signal conductor 841. The distance between the ground conductors 843a and 843b and the signal conductor 841 is less than 90% of the first distance D1 (for example, 0.1 mm).

[0031] The values ​​of each parameter of signal line 1 used in the simulation are as follows (see Figures 4A and 4B): relative permittivity εr of substrate 11 = 9.6, thickness T1 of substrate 11 (i.e., dielectric thickness T1 between the first signal conductor 21 and the second ground conductor 23 = first distance D1) = 0.12 mm, dimensions shown in Figure 4A: L1 = 0.6375 mm, L2 = 0.046 mm, L3 = 0.027 mm, L4 = 0.275 mm, L5 = 0.0125 mm, L6 = 0.1 mm, φ7 = 0.05 mm, L10 = 1.4 mm, L11 = 0.115 mm, L13 = 0.1 mm, Lex = 0.3 mm, Gex = 0.18 mm, L21 = 0.075 mm, and thickness t of each conductor = 0.004 mm. It should be noted that the parameter values ​​listed above are merely representative examples, and the values ​​of each parameter that can improve transmission characteristics are not limited to those listed above.

[0032] As shown in Figure 2, the signal lines 80A and 80B of Comparative Examples 1 and 2 have good transmission characteristics because they do not have a connection point where the electromagnetic wave mode is switched. In the field of high-frequency signal transmission, there is a demand for Comparative Examples 3 and 4, which combine the signal lines 80A and 80B of Comparative Examples 1 and 2. That is, the coplanar signal line 80A (i.e., Comparative Example 1) has the signal conductor 821 and the ground conductors 822a and 822b located on the upper surface of the substrate, so good connections with electronic elements can be made. On the other hand, the microstrip signal line 80B (i.e., Comparative Example 2) has a wide line width of the signal conductor 831, which reduces conductor loss, making it advantageous for long signal lines. Therefore, the advantages of both can be obtained by combining the signal lines 80A and 80B.

[0033] In Comparative Example 3, the signal line 80C has a reverse-facing tapered shape for the signal conductor 841 at the connection point 84, eliminating the steep step in the line width of the signal conductors 821, 841, and 831. However, electromagnetic wave leakage occurs due to the switching of the vibration mode of the electromagnetic wave at the connection point 84, resulting in high loss in the frequency band above 130 GHz, as shown in Figure 2.

[0034] In Comparative Example 4, the signal line 80D achieves a smooth transition of electromagnetic wave vibration modes by realizing a transmission section with a mixed mode of GCPW mode and MSL mode at the connection point 84D between the coplanar line 82 and the microstrip line 83. However, leakage of electromagnetic waves in the GCPW mode, which is included in the mixed mode, occurs at the boundary between the connection point 84D and the microstrip line 83, resulting in high loss in the frequency band above 160 GHz, as shown in Figure 2.

[0035] As a result of the aforementioned effects, the signal line 1 of Embodiment 1 exhibits low loss and good transmission characteristics in a frequency band of 190 GHz or higher, as shown in Figure 2.

[0036] (Embodiments 2 and 3) Figure 5 is a plan view showing the main part of the signal line 1A of Embodiment 2 of the present disclosure. Figure 6 is a longitudinal cross-sectional view showing the main part of the signal line 1B of Embodiment 3 of the present disclosure. The cross-sectional position in Figure 6 corresponds to the position of the line A1-A1 in Figure 4A. The signal lines 1A and 1B of Embodiments 2 and 3 differ from Embodiment 1 mainly in the structure between the fourth grounding conductor 42 and the first grounding conductors 22a and 22b, but other than this structure, they may be the same as Embodiment 1.

[0037] As shown in the signal line 1A of Embodiment 2 (see Figure 5), the fourth grounding conductor 42 may be separated from the first grounding conductors 22a and 22b. The corner E2 of the fourth grounding conductor 42 in the Y direction near the first grounding conductors 22a and 22b (see Figure 5) may have a rounded shape (specifically, an r-shaped shape).

[0038] As shown in the signal line 1B of Embodiment 3 (see Figure 6), the fourth ground conductor 42 may be positioned away from the first ground conductors 22a and 22b, while a connecting conductor 47 connecting the first via conductor 24 and the second via conductor 43 is positioned there. The connecting conductor 47 may be positioned at any height between the first plane S1 and the third ground conductor 32, but being closer to the first plane S1 can improve transmission characteristics in higher frequency bands. The connecting conductor 47 may be a film-like conductor extending parallel to the first plane S1. In a planar perspective view, the connecting conductor 47 may be positioned at a location that overlaps with the shortest path between the fourth ground conductor 42 and the first ground conductors 22a and 22b.

[0039] Figure 7 is a graph showing the frequency characteristics of the signal lines of Embodiments 2 and 3. "Embodiment 3-a," "Embodiment 3-b," and "Embodiment 3-c" in the graph represent signal lines where the height H1 of the connecting conductor 47 (see Figure 6) is 1 / 4, 1 / 2, and 3 / 4, respectively. This height is expressed as a ratio of the normalized length, with the height of the upper surface of the third grounding conductor 32 set to "1" and the height of the first surface S1 set to "0."

[0040] As shown in region B1 of Figure 7, the signal line 1A of Embodiment 2 has lower losses and better transmission characteristics than Comparative Example 3 in the frequency band of 70 to 170 GHz. In this signal line 1A, capacitive and inductive components are generated at a distance between the first ground conductors 22a and 22b and the fourth ground conductor 42. Due to these components, a resonance effect appears at a certain frequency ω1. The signal line 1B of Embodiment 3 has lower losses and better transmission characteristics over a higher frequency band than Embodiment 2. In the signal line 1B of Embodiment 3, the connecting conductor 47 reduces the above-mentioned capacitive and inductive components, thereby reducing the resonance effect.

[0041] (Embodiments 4-6) Figures 8A to 8C are longitudinal cross-sectional views showing the main parts of the signal lines 1C to 1E of Embodiments 4, 5, and 6 of the present disclosure, respectively. The location of the cross-section corresponds to the location of the line A1-A1 in Figure 3. The structure of the signal lines 1C to 1E at the location of the cross-section differs from the structure of the signal line 1 in Figure 3. The signal lines 1C to 1E of Embodiments 4 to 6 differ from Embodiment 1 mainly in the position of the fourth grounding conductor 42 in the Z direction and the connection structure between the fourth grounding conductor 42 and the first grounding conductors 22a and 22b. Other than the position and connection structure, they may be the same as Embodiment 1.

[0042] As shown in the signal lines 1C to 1E of Embodiments 4 to 6 (see Figures 8A to 8C), the fourth grounding conductor 42 may be located between the first surface S1 and the third grounding conductor 32 in the Z direction, i.e., in the inner layer of the substrate 11. However, the closer the fourth grounding conductor 42 is to the first surface S1, the better the transmission characteristics can be obtained up to higher frequency bands.

[0043] As shown in FIG. 8A, the fourth ground conductor 42 located in the inner layer of the substrate 11 may extend to the first via conductor 24 and be connected (specifically, in contact) to the first via conductor 24. Alternatively, as shown in FIG. 8B, the fourth ground conductor 42 located in the inner layer of the substrate 11 may extend so as to bend in the Z direction and be connected (specifically, in contact) to the first ground conductors 22a and 22b from the Z direction. Alternatively, as shown in FIG. 8C, the fourth ground conductor 42 located in the substrate 11 may be separated from the first ground conductors 22a and 22b and the first via conductor 24.

[0044] FIG. 9 is a graph showing the frequency characteristics of the signal lines 1C to 1E of Embodiments 4 to 6. The frequency characteristics of Embodiments 4 to 6 in FIG. 9 are calculated with the height H2 (see FIG. 8A) of the fourth ground conductor 42 being 1 / 2 of the height. The height is represented by the ratio of the normalized length with the height of the third ground conductor 32 being "1" and the height of the first surface S1 being "0".

[0045] The signal lines 1C to 1E of Embodiments 4 to 6 in which the fourth ground conductor 42 is located in the inner layer of the substrate 11 have lower losses than Comparative Example 3 in the frequency band of 70 GHz to 170 GHz and have good transmission characteristics, as shown in Region B2 of FIG. 9. In the signal line 1E of Embodiment 6, a capacitance component and an inductance component occur between the first ground conductors 22a and 22b and the fourth ground conductor 42, and a resonance effect appears at a certain frequency ω2. The signal lines 1C and 1D of Embodiments 4 and 5 have less of the above resonance effect, and good transmission characteristics are obtained up to a higher frequency band compared to Comparative Example 3 and Embodiment 6.

[0046] FIG. 10 is a graph showing the frequency characteristics of the signal line 1C of Embodiment 4 in which the position of the fourth ground conductor is varied in the Z direction. "Embodiment 4-1 / 4", "Embodiment 4-2 / 4", and "Embodiment 4-3 / 4" in the graph represent signal lines in which the height H2 (see FIG. 8A) of the fourth ground conductor 42 is 1 / 4, 2 / 4, and 3 / 4 of the height, respectively. The height is represented by the ratio of the normalized length with the height of the third ground conductor 32 being "1" and the height of the first surface S1 being "0".

[0047] As shown in FIG. 10, the fourth ground conductor 42 located in the inner layer of the substrate 11 has good transmission characteristics up to a higher frequency band as it is closer to the first surface S1.

[0048] (Comparative Examples 5 and 6) FIGS. 11A and 11B are diagrams showing the signal lines 80E and 80F of Comparative Example 5 and Comparative Example 6. FIG. 12 is a graph showing the frequency characteristics of the signal lines 80E and 80F of Comparative Examples 5 and 6. The signal line 80E of Comparative Example 5 corresponds to a configuration in which the fourth ground conductor 42 is removed from the signal line 1 of Embodiment 1 leaving the second via conductor 43. The signal line 80F of Comparative Example 6 corresponds to a configuration in which a plurality of second via conductors 43 are removed from the signal line 1 of Embodiment 1 leaving the fourth ground conductor 42.

[0049] As shown in region B3 of FIG. 12, the signal line 80E of Comparative Example 5 has high losses from 70 GHz to 170 GHz and has little effect of suppressing electromagnetic wave leakage at the connection portion 4. Further, in the signal line 80E of Comparative Example 5, a resonance effect occurs at a high frequency ω3 due to a capacitance component or the like generated between the second via conductor 43 and the second ground conductor 23. In the signal line 80F of Comparative Example 6, a resonance effect occurs at a low frequency ω4 due to electrical vibration on the fourth ground conductor 42 where one end is grounded and the other end is an open end in the Y direction.

[0050] From the frequency characteristics of Comparative Examples 5 and 6, it is shown that better transmission characteristics can be obtained by having both the fourth ground conductor 42 and the second via conductor 43 as in the present embodiment.

[0051] (Gap width Gex) Next, we will explain the gap width Gex between the fourth ground conductor 42 and the second signal conductor 31. Figure 13 is a graph showing the relationship between the gap width Gex and the loss at a specific frequency. The vertical axis represents the insertion loss, with values ​​close to 0 dB indicating low loss and negative values ​​with large absolute values ​​indicating high loss. As the specific frequency mentioned above, we have adopted 180 GHz, which is the frequency at which the loss is high in the signal line 80C of Comparative Example 3. Figure 14 is a graph showing the relationship between the gap width Gex and the frequency at which the first loss occurs. For the first loss, we have adopted a value of "-0.2 dB" which is within the acceptable range of the total loss, including insertion loss and reflection loss, and close to the boundary of acceptance. Note that the values ​​in Figures 13 and 14 are obtained by changing some of the values ​​of the common parameters used in the simulation from the values ​​of the parameters used to obtain the graph in Figure 2 (specifically, the value of dimension L4). However, this change does not affect the pattern in which the insertion loss changes when the width Gex is changed.

[0052] As shown in region C1 of Figure 13, the loss is very low when the width Gex of the gap 51 is between 0.12 mm and 0.18 mm. As the width is reduced below 0.12 mm, the loss gradually increases, and then increases more rapidly. On the other hand, as the width Gex of the gap 51 is increased above 0.18 mm, the loss increases more gradually.

[0053] As shown in region C2 of Figure 14, the width Gex of the gap 51 can increase the frequency at which the first loss occurs when it is between 0.1 mm and 0.2 mm, and in particular, the frequency at which the first loss occurs can be increased even more when it is around 0.18 mm.

[0054] In the simulation for calculating the graph lines in Figures 13 and 14, the value of the first distance D1 (see Figure 4B), which indicates the distance between the second signal conductor 31 and the third ground conductor 32 of the signal line 1, is 0.12 mm.

[0055] As mentioned above, the width Gex of the gap 51 may be 90% or more of the first distance D1, and with this configuration, good transmission characteristics can be obtained as shown in Figures 13 and 14. As shown in Figures 13 and 14, the width Gex of the gap 51 may be 90% or more and 180% or less of the first distance D1 in order to obtain even better transmission characteristics, or it may be 100% or more and 150% or less of the first distance D1 in order to obtain even better transmission characteristics.

[0056] (Length Lex of the fourth grounding conductor 42 in the Y direction) Next, we will explain the length Lex of the fourth grounding conductor 42 in the Y direction. Figure 15 is a graph showing the relationship between length Lex and loss at a specific frequency. The vertical axis shows the insertion loss, with values ​​close to 0 dB indicating low loss and negative values ​​with large absolute values ​​indicating high loss. As the specific frequency mentioned above, 180 GH, which is high in signal line 80C of Comparative Example 3, is used. Figure 16 is a graph showing the relationship between length Lex and the frequency leading to the first loss. For the first loss, a value of "-0.2 dB" is adopted, which is within the acceptable range of the total loss, including insertion loss and reflection loss, and close to the boundary of acceptance. Note that the values ​​in Figures 15 and 16 are obtained by changing some of the values ​​of the common parameters in the simulation from the values ​​of the parameters used to obtain the graph in Figure 2 (specifically, the value of dimension L4). However, this change does not affect the pattern of how the insertion loss changes when length Lex is changed.

[0057] As shown in region C3 of Figure 15, the loss is low when the length Lex of the fourth grounding conductor 42 is 0.3 mm or more, the loss gradually increases when it is shorter than 0.3 mm, and the loss increases sharply when it is 0.2 mm or less.

[0058] As shown in region C4 of Figure 16, a length Lex of the fourth ground conductor 42 of approximately 0.3 mm allows for a very high frequency to be reached when the first loss occurs. Furthermore, as shown in region C5 of Figure 16, a length Lex of 0.3 mm or more and less than 0.8 mm allows for a frequency of 190 GHz or higher to be reached when the first loss occurs.

[0059] As described above, the fourth grounding conductor 42 and the multiple second via conductors 43 act to block electromagnetic waves leaking from the connection 4 from being emitted to the outside, and to send the electric field component of the electromagnetic waves back to the first grounding conductors 22a, 22b or the second grounding conductor 23. Theoretically, the minimum size of the structure that contributes to blocking electromagnetic waves is proportional to the wavelength of the electromagnetic waves. Therefore, the length Lex of the fourth grounding conductor 42, which enables the good transmission characteristics described above, is estimated to be a value proportional to the wavelength of the electromagnetic waves, and is a value converted based on the wavelength of the electromagnetic waves whose leakage is being blocked.

[0060] In this embodiment, the frequency bandwidth of the target transmission signal for which leakage from the connection part 4 is to be reduced and transmission characteristics are to be improved is 190 GHz. Therefore, when converted using the effective wavelength λeff = 0.57 mm for 190 GHz in the simulation, the optimal length Lex of the fourth ground conductor 42 can be expressed as being around 0.3 mm = 1 / 2λeff. Since the electromagnetic field spreads not only within the substrate 11 but also in the air, the effective relative permittivity of the transmission line is smaller than the relative permittivity of the substrate 11.

[0061] Based on the above results, the length Lex of the fourth grounding conductor 42 in the Y direction may be set to approximately 1 / 2・λeff, with respect to the effective wavelength λeff of the target transmission signal whose characteristics are to be improved (for example, a 190 GHz signal), i.e., 1 / 2・λeff × 70% or more and 1 / 2・λeff × 130% or less. By adopting this length Lex, the loss of the target transmission signal can be reduced, and the transmission characteristics of the target transmission signal can be further improved.

[0062] (Embodiments 7-9) Figures 17A to 17C are perspective views showing signal lines 1F to 1H of Embodiments 7, 8, and 9 of the present disclosure, respectively. Figure 18 is a graph showing the frequency characteristics of signal lines 1F to 1H of Embodiments 7-9.

[0063] As shown in the signal lines 1F and 1G of embodiments 7 and 8 (see Figures 17A and 17B), a connection section 4 having a mixed section 6 for GCPW mode and MSL mode may be located between the coplanar line 2 and the microstrip line 3. The fourth ground conductor 42 and the second via conductor 43 may be located at one end of the mixed section 6 (i.e., on the coplanar line 2 side).

[0064] The connection portion 4 of the embodiment 7 may have a configuration comprising a pair of fifth ground conductors 44Fa and 44Fb that are continuous with the pair of first ground conductors 22a and 22b, respectively, and a plurality of third via conductors 45F that are located between the fifth ground conductors 44Fa and 44Fb and the third ground conductor 32. The pair of fifth ground conductors 44Fa and 44Fb are film-like conductors located on the first surface S1 so as to sandwich the third signal conductor 41, and the distance from the third signal conductor 41 may gradually increase toward the microstrip line 3.

[0065] The connection portion 4 of embodiment 8 may have a configuration comprising a pair of sixth ground conductors 44Ga, 44Gb that are continuous with the pair of first ground conductors 22a, 22b, respectively, and a plurality of third via conductors 45G that are located between the sixth ground conductors 44Ga, 44Gb and the third ground conductor 32. The pair of sixth ground conductors 44Ga, 44Gb are film-like conductors located on the first surface S1 so as to sandwich the third signal conductor 41, and the distance from the third signal conductor 41 may be less than 90% of the first distance D1 so as to induce electromagnetic waves in GCPW mode. The line width of the third signal conductor 41 sandwiched between the pair of sixth ground conductors 44Ga, 44Gb may be the same as the line width of the second signal conductor 31 of the microstrip line 3. Furthermore, the coplanar line 2 side of the third signal conductor 41, and the coplanar line 2 side of the sixth ground conductors 44Ga and 44Gb may have tapered portions so as not to produce sharp corners in the outline in planar perspective.

[0066] As shown in Figure 18, even in signal lines 1F and 1G with long connection sections where GCPW mode and MSL mode are mixed 6, the leakage of electromagnetic waves in GCPW mode is reduced by the action of the fourth grounding conductor 42 and the second via conductor 43, and good transmission characteristics are obtained over high frequency bands. That is, at the boundary between the mixed section 6 and the coplanar line 2, when electromagnetic waves in GCPW mode contained in the mixed section 6 are about to leak, the fourth grounding conductor 42 and the second via conductor 43 block the leakage of such electromagnetic waves and return them to the first grounding conductors 22a, 22b or the second grounding conductor 23.

[0067] As shown in the signal line 1H of Embodiment 9 (see Figure 17C), the fourth ground conductor 42 and the second via conductor 43 may be located only on one side of the second signal conductor 31 in the X direction. In this configuration as well, leakage of GCPW mode electromagnetic waves can be reduced on one side, and as shown in Figure 18, losses can be reduced in a high frequency band of 120 GHz or higher compared to Comparative Example 3, and good transmission characteristics can be obtained.

[0068] (Embodiments 10-12) Figures 19A to 19C are plan views showing the main parts of the signal lines 1I to 1K of Embodiments 10, 11, and 12 of the present disclosure, respectively.

[0069] As shown in the signal line 1I of Embodiment 10 (see Figure 10A), the corners F1 and F2 of the fourth grounding conductor 42 near the first grounding conductors 22a and 22b in the Y direction may have an angular shape (for example, a right-angle shape). Conversely, as described in Embodiment 2 above, the corner E2 of the fourth grounding conductor 42 near the first grounding conductors 22a and 22b in the Y direction (see Figure 5) may have a rounded shape (specifically, an r-shaped shape).

[0070] As shown in the signal line 1J of Embodiment 11 (see Figure 10B), the corners F3 and F4 of the fourth grounding conductor 42 opposite to the first grounding conductors 22a and 22b in the Y direction may have an angular shape (for example, a right-angle shape). Conversely, as described in Embodiment 1 above, the corner E1 of the fourth grounding conductor 42 opposite to the first grounding conductors 22a and 22b in the Y direction (see Figure 1A) may have a rounded shape (specifically, an r-shaped shape).

[0071] The signal lines 1I and 1J in embodiments 10 and 11 differ from the signal lines 1A and 1 in embodiments 2 and 1, respectively, only by a slight increase in loss, and thus achieve the same good transmission characteristics as embodiments 2 and 1.

[0072] As in the signal line 1K of Embodiment 12, the corners F5 and F6 on the connection portion 4 side in the Y direction of the first ground conductors 22a and 22b may have a rounded shape (specifically, an r-shaped design). The signal line 1K of Embodiment 12 differs from the signal line 1 of Embodiment 1 only in that the loss is slightly lower, and good transmission characteristics similar to those of Embodiment 1 can be obtained.

[0073] A gap is created between the corners of the fourth ground conductor 42 (for example, corners F1 to F4) and the second via conductor 43 closest to the corner, with a dielectric (i.e., a part of the substrate 11) in between, and this gap becomes a capacitive component. If the corner has a sharp shape, the gap widens and the capacitive component increases. On the other hand, if the corner has a rounded shape, the gap narrows and the capacitive component decreases. Therefore, having a rounded shape for the corners can eliminate unnecessary capacitive components and further improve transmission characteristics. The effect of the rounded shape is particularly large when the diameter of the second via conductor 43 is small, or when the area of ​​the fourth ground conductor 42 that extends beyond the second via conductor 43 in a planar view is large. In a planar perspective view, the lengths L31 to L34 from the tip of the corners F1 to F4 to the nearby second via conductor 43 (see Figures 19A and 19B) may be less than or equal to λeff / 12. This length further reduces the influence of the capacitance component and improves the transmission characteristics.

[0074] Similarly, at the corners F5 to F6 of the first ground conductors 22a and 22b, a gap with a dielectric material in between is created between them and nearby ground conductors (e.g., second ground conductor 23, third ground conductor 32, etc.) and nearby via conductors (e.g., first via conductor 24, second via conductor 43, etc.), and this gap becomes a capacitive component. If the corner has a sharp shape, the gap widens and the capacitive component increases. On the other hand, if the corner has a rounded shape, the gap narrows and the capacitive component decreases. Therefore, having a rounded shape for the corner eliminates unnecessary capacitive components and further improves transmission characteristics. The effect of the rounded shape is particularly large when the diameter of the first via conductor 24 is small, or when the area of ​​the first ground conductors 22a and 22b that protrude from the first via conductor 24 in a planar view is large.

[0075] (Embodiments 13-16) Figures 20A to 20D are plan views showing the main parts of the signal lines 1L to 1O of Embodiments 13, 14, 15, and 16 of the present disclosure, respectively. Figure 21 is a graph showing the frequency characteristics of the signal lines 1L to 1O of Embodiments 13 to 16.

[0076] As in the signal line 1L of Embodiment 13, the side 42a of the fourth grounding conductor 42 on the second signal conductor 31 side may be inclined from the Y direction. The inclination may be in a direction away from the second signal conductor 31 as it moves away from the coplanar line 2.

[0077] As in the signal line 1M of Embodiment 14, the side 42b of the fourth grounding conductor 42 on the second signal conductor 31 side may have a stepped shape in planar perspective. The stepped shape may be such that it moves away from the second signal conductor 31 as it moves away from the coplanar line 2.

[0078] In embodiments 13 and 14, the width of the gap 51 in the X direction between the fourth ground conductor 42 and the second signal conductor 31 is not constant, but in at least a portion of the range, the width of the gap 51 may be 0.9 times the first distance D1 or more. This configuration reduces the leakage of electromagnetic waves in GCPW mode and improves transmission characteristics. Alternatively, the width of the gap 51 in the X direction may be within the range of 0.9 to 1.5 times the first distance D1 over the entire area overlapping with the second region 13 (see also Figure 1) where the microstrip line 3 is located. This configuration significantly reduces the leakage of electromagnetic waves in GCPW mode and further improves transmission characteristics.

[0079] As in the signal lines 1N and 1O of embodiments 15 and 16, the fourth grounding conductor 42 may have a large width in the X direction. The width in the X direction of the fourth grounding conductor 42 in embodiment 15 is at least twice that of the fourth grounding conductor 42 in embodiment 1, and the width of the fourth grounding conductor 42 in embodiment 16 is at least three times that of the fourth grounding conductor 42 in embodiment 1.

[0080] As shown in Figure 21, the signal lines 1L to 1O of Embodiments 13 to 16 also provide the same good transmission characteristics as the signal line 1 of Embodiment 1.

[0081] (Embodiments 17-19) Figures 22A-22C are perspective views showing signal lines 1P-1R of Embodiments 17, 18, and 19 of the present disclosure. Figure 23 is a graph showing the frequency characteristics of signal lines 1P-1R of Embodiments 17-19 and Comparative Example 7. The main difference between the signal lines 1P-1R of Embodiments 17-19 and Embodiments 1-16 is that the substrate material of the base 11 is a fluororesin with a relative permittivity εr = 2.2 (for example, Teflon®). In the signal lines 1P-1R of these embodiments, a fluororesin substrate 11 is used. The fluororesin substrate 11 has the same thickness as alumina but a low dielectric constant, which increases the effective wavelength of signal propagation and reduces loss. Therefore, it is possible to cover the D band of radio waves (i.e., 110 GHz to 170 GHz) or 110 GHz to 190 GHz without applying the configuration of the present disclosure. Therefore, by applying the configuration of this disclosure, further improvements in characteristics can be expected in the high-frequency range, and it is anticipated that, for example, the G band of radio waves (i.e., 140 GHz to 220 GHz) can be covered. Accordingly, in embodiments 17 to 19, the maximum frequency of the usable bandwidth is set to 220 GHz, and the effective wavelength λeff of the target transmission signal corresponds to the effective wavelength of a 220 GHz transmission signal. Note that the dielectric constant of the substrate 11 and the applicable frequency band are not limited to those described above.

[0082] The parameters of each signal line 1P to 1R in embodiments 17 to 19 may be designed so that the impedance of the coplanar line 2 and the impedance of the microstrip line 3 are set to predetermined values ​​in accordance with the frequency of the transmitted signal. In the example shown in Figures 22A to 22C, the thickness T1 of the base 11 is 0.12 mm, the line width W21 of the first signal conductor 21 is 0.24 mm, the length L21 in the X direction of the gap between the first signal conductor 21 and the first ground conductors 22a and 22b is 0.03 mm, and the line width W31 of the second signal conductor 31 is 0.36 mm, etc. The signal lines 1P to 1R in embodiments 17 to 19 may have the same structure as the signal lines 1, 1A, and 1C of embodiments 1, 2, and 4, respectively, except that the relative permittivity εr and each of the above parameters are different.

[0083] In the signal lines 1P to 1R of embodiments 17 to 19, the relative permittivity εr of the substrate 11 is different compared to embodiments 1 to 16, resulting in a difference in the effective wavelength λeff of the target transmission signal. In embodiments 1 to 16, λeff = 0.57 mm, while in embodiments 17 to 19, λeff = 0.96 mm.

[0084] However, regardless of the difference in effective wavelength λeff, a gap 51 may be located between the second signal conductor 31 and the fourth ground conductor 42, with a width in the X direction of 90% or more of the first distance D1. The fourth ground conductor 42, located across this gap 51, reduces leakage of GCPW mode electromagnetic waves from the connection 4 to the outside, thereby improving transmission characteristics.

[0085] Furthermore, the length of the fourth grounding conductor 42 in the Y direction may be set to 70% to 130% of 1 / 2・λeff. A fourth grounding conductor 42 of this length can further reduce the leakage of GCPW mode electromagnetic waves from the connection part 4 to the outside, thereby improving the transmission characteristics.

[0086] In the graph of Figure 23, the characteristic curves for embodiments 17 to 19 were calculated using a width in the X direction of the gap 51 between the fourth ground conductor 42 and the second signal conductor 31, Gex = 0.15 mm, and a length in the Y direction of the fourth ground conductor 42, Lex = 0.4 mm. Comparative example 7 in the graph of Figure 23 shows the characteristic curve of a signal line obtained by removing the fourth ground conductor 42 and the second via conductor 43 from the signal line 1P of embodiment 17.

[0087] As shown in Figure 23, in the signal lines 1P to 1R of Embodiments 17 to 19, the loss is reduced in the range from 100 GHz to over 200 GHz compared to Comparative Example 7, and good transmission characteristics are obtained. Even if the relative permittivity εr of the substrate 11 is different, the same structure as the signal lines 1, 1A to 1O of Embodiments 1 to 16 may be adopted, and good transmission characteristics similar to those of Embodiments 1 to 16 can be obtained with this structure.

[0088] (Package for housing electronic components and electronic device) Figures 24A and 24B are a longitudinal section view and a plan view, respectively, showing an electronic component housing package and an electronic device according to an embodiment of the present disclosure. Figure 24A shows a cross-section along line A-A in Figure 24B. The electronic component housing package 200 according to an embodiment of the present disclosure may include a housing 201 having a housing section 203 for housing an electronic component 301, a lid 204 that closes the opening of the housing section 203, and a coaxial line 202 that transmits a high-frequency signal between the outside and inside of the housing 201. The electronic component housing package 200 may further include a signal line 1 of Embodiment 1 that transmits a signal between the coaxial line 202 and the electronic component 301. The signal line 1 is located on a wiring board 100, and the wiring board 100 may be joined to the housing 201. The signal line 1 may be replaced by the signal lines 1A to 1R of the other embodiments described above.

[0089] An electronic device 300 according to the embodiment of this disclosure may include an electronic component housing package 200 and an electronic component 301 housed in a housing section 203.

[0090] The signal line 1 may be positioned such that one end of the microstrip line 3 is connected to the coaxial line 202, and one end of the coplanar line 2 is connected to the electronic component 301.

[0091] The electronic component 301 is a semiconductor element and may include a signal electrode 302 located on its upper surface and a pair of ground electrodes 303a and 303b located on the upper surface so as to sandwich the signal electrode 302. The first signal conductor 21 of the coplanar line 2 may be connected to the signal electrode 302 via a bonding material w such as a bonding wire, and the first ground conductors 22a and 22b of the coplanar line 2 may be connected to the ground electrodes 303a and 303b via a bonding material w such as a bonding wire.

[0092] With the above-described configuration of the electronic component housing package 200 and electronic device 300, signals can be transmitted between the electronic component 301 and the outside of the housing 203 with low loss and good transmission characteristics over a high frequency band such as 190 GHz via the signal line 1.

[0093] The embodiments of the present disclosure have been described above. However, the signal lines, wiring boards, electronic component housing packages, and electronic devices of the present disclosure are not limited to the embodiments described above. The details shown in the embodiments can be modified as appropriate without departing from the spirit of the invention.

[0094] An embodiment of the present disclosure is shown below. In one embodiment, (1) the signal line comprises: a dielectric substrate having a first surface; a coplanar line having a first signal conductor located on the first surface; a pair of first ground conductors located on the first surface with the first signal conductor in between; a second ground conductor located on the substrate and facing the first signal conductor and the pair of first ground conductors; and a plurality of first via conductors located between the pair of first ground conductors and the second ground conductors; a microstrip line connected to the coplanar line having a second signal conductor located on the first surface and a third ground conductor located on the substrate and facing the second signal conductor; a fourth ground conductor located on the side of the second signal conductor and on the side of the connection between the microstrip line and the coplanar line in a planar perspective view; and a plurality of second via conductors located between the fourth ground conductor and the third ground conductor. When the distance between the second signal conductor and the third ground conductor is called the first distance, the longitudinal direction of the second signal conductor is called the Y direction, and the direction perpendicular to the Y direction in a planar perspective is called the X direction, a gap exists between the second signal conductor and the fourth ground conductor with a width in the X direction of 90% or more of the first distance.

[0095] (2) The signal line in (1) above has the fourth grounding conductor extending to the first grounding conductor or the first via conductor.

[0096] (3) In the signal line described in (1) above, the fourth grounding conductor is located on the first plane and extends to the first grounding conductor.

[0097] (4) In any one of the signal lines described in (1) to (3) above, a gap exists between the second signal conductor and the fourth ground conductor in a planar perspective view, with a width in the X direction of 90% or more of the first distance and 150% or less of the first distance.

[0098] (5) In any one of the signal lines described in (1) to (4) above, when the effective wavelength of the target transmission signal is λeff, the length of the fourth ground conductor in the Y direction is λeff / 2 × 70% or more and λeff / 2 × 130% or less.

[0099] In one embodiment, (6) the wiring board includes one of the signal lines described in (1) to (5) above.

[0100] In one embodiment, (7) the electronic component housing package includes one of the signal lines described in (1) to (5) above.

[0101] In one embodiment, (8) the electronic device comprises the electronic component housing package described in (7) above, and the electronic component housing the electronic component housing package.

[0102] This disclosure can be used in signal lines, wiring boards, electronic component housing packages, and electronic devices.

[0103] 1. 1A-1R Signal lines 2 Coplanar lines 3 Microstrip lines 4 Connection section 6 Mixed section 21 First signal conductor 22a, 22b First ground conductor 23 Second ground conductor 24 First via conductor 31 Second signal conductor 32 Third ground conductor 41 Third signal conductor 42 Fourth ground conductor 43 Second via conductors 44Fa, 44Fb Fifth ground conductors 44Ga, 44Gb Sixth ground conductors 45F, 45G Third via conductor 47 Connecting conductor 51 Gap 11 Base S1 First surface S2 Second surface D1 First distance Lex Length of fourth ground conductor Gex Gap width 100 Wiring board 200 Package for electronic components 300 Electronic device 301 Electronic components

Claims

1. A dielectric substrate having a first surface; a coplanar line having a first signal conductor located on the first surface, a pair of first ground conductors located on the first surface with the first signal conductor in between, a second ground conductor located on the substrate and facing the first signal conductor and the pair of first ground conductors, and a plurality of first via conductors located between the pair of first ground conductors and the second ground conductors; a microstrip line connected to the coplanar line, having a second signal conductor located on the first surface and a third ground conductor located on the substrate and facing the second signal conductor; a fourth ground conductor located on the side of the second signal conductor and on the connection side between the microstrip line and the coplanar line in a planar perspective view; and a plurality of second via conductors located between the fourth ground conductor and the third ground conductor. A signal line in which, when the distance between the second signal conductor and the third ground conductor is called the first distance, the longitudinal direction of the second signal conductor is called the Y direction, and the direction perpendicular to the Y direction in a planar perspective is called the X direction, there is a gap between the second signal conductor and the fourth ground conductor whose width in the X direction is 90% or more of the first distance.

2. The signal line according to claim 1, wherein the fourth grounding conductor extends to the first grounding conductor or the first via conductor.

3. The signal line according to claim 1, wherein the fourth grounding conductor is located on the first plane and extends to the first grounding conductor.

4. The signal line according to any one of claims 1 to 3, wherein, in a planar perspective view, a gap exists between the second signal conductor and the fourth ground conductor, the width of which in the X direction is 90% or more of the first distance and 150% or less of the first distance.

5. The signal line according to any one of claims 1 to 4, wherein, when the effective wavelength of the target transmission signal is λeff, the length of the fourth ground conductor in the Y direction is λeff / 2 × 70% or more and λeff / 2 × 130% or less.

6. A wiring board comprising the signal line described in any one of claims 1 to 5.

7. An electronic component housing package comprising a signal line according to any one of claims 1 to 5.

8. An electronic device comprising: an electronic component storage package according to claim 7; and an electronic component stored in the electronic component storage package.

Images