Wiring board, package for housing electronic component, and electronic module

Abstract

One embodiment of a wiring board of the present invention includes: an insulating substrate; at least one signal conductor pair; and a plurality of ground conductors. The signal conductor pair is positioned on the surface of the insulating substrate and includes a pair of signal conductors. On the surface of the insulating substrate, the ground conductors are positioned between the pair of signal conductors and so as to be set apart from the signal conductors on both sides thereof. The wiring board has at least one bi-curved part which forms curved sections in which both signal conductors of the pair of signal conductors curve following each other. In at least one of the bi-curved parts, the curved section having the smaller curve diameter is configured so that a first interval with respect to the ground conductor adjacent to the curve-direction inner side is narrower than a second interval with respect to the ground conductor adjacent to the curve-direction outer side, and the curved section having the larger curve diameter is configured so that a third interval with respect to the ground conductor adjacent to the curve-direction inner side is equal to a fourth interval with respect to the ground conductor adjacent to the curve-direction outer side.

Description

Wiring board, package for storing electronic components, and electronic module

[0001] The present disclosure relates to a wiring board, an electronic component storage package, and an electronic module.

[0002] Conventionally, there is known a technique for forming ground conductors on both sides of a signal conductor for high-frequency transmission for the purposes of electromagnetic shielding, adjusting characteristic impedance, etc. Furthermore, Patent Document 1 discloses a technique for making the distance between the signal conductor and the ground conductor at the bend greater than the distance between the signal conductor and the ground conductor at the straight portion in order to reduce signal reflection at the bend of the signal conductor.

[0003] JP 2010-109243 A

[0004] The wiring board according to the present disclosure comprises: an insulating base; one or more signal conductor pairs, each of which is located on the surface of the insulating base and has a pair of signal conductors; and a plurality of ground conductors, each of which is located on the surface of the insulating base between the pair of signal conductors and on both sides of the pair of signal conductors, with a gap between them, wherein each of the signal conductors in the pair has one or more curved portions that curve along each other, and in at least one of the curved portions, the curved portion with a smaller curved diameter is an inner narrow-spaced curved portion in which a first gap between the adjacent ground conductor on the inside in the curved direction is narrower than a second gap between the adjacent ground conductor on the outside in the curved direction, and the curved portion with a larger curved diameter is a bilateral equally-spaced curved portion in which a third gap between the adjacent ground conductor on the inside in the curved direction is equal to a fourth gap between the adjacent ground conductor on the outside in the curved direction.

[0005] Furthermore, the wiring board according to the present disclosure comprises: an insulating base; one or more signal conductor pairs located on the surface of the insulating base and having a pair of signal conductors; and a plurality of ground conductors located on the surface of the insulating base between and on both sides of the pair of signal conductors at intervals from the signal conductors, wherein the wiring board has one or more one-sided curved portions in which one signal conductor of the pair is a straight portion while the other signal conductor is a curved portion, and in at least one of the one-sided curved portions, the curved portion is an inner narrow-spaced curved portion in which a first gap between the adjacent ground conductor on the inside in the curved direction and the adjacent ground conductor on the outside in the curved direction is narrower than a second gap between the adjacent ground conductor on the straight portion and the adjacent ground conductor on the side opposite to the curved portion, and

[0006] Furthermore, the electronic component storage package according to the present disclosure includes a substrate, a frame body positioned on the substrate, and a wiring board joined to the frame body.

[0007] Furthermore, the electronic module according to the present disclosure includes a package for storing an electronic component, an electronic component located on the substrate and electrically connected to the signal conductor pair, and a lid located on the frame.

[0008] 5 is a plan view of a wiring board according to one embodiment (Embodiment A) of the present disclosure. FIG. 5 is an enlarged view of a main portion II including both curved portions in FIG. 1. FIG. 5 is an enlarged view of a main portion III including one curved portion in FIG. 1. FIG. 5 is a plan view of an inner layer conductor provided in the wiring board shown in FIG. 1. FIG. 5 is a plan view of a wiring board according to another embodiment (Embodiment B) of the present disclosure. FIG. 5 is an enlarged view of a main portion VI including both curved portions in FIG. 5. FIG. 5 is an enlarged view of a main portion VII including one curved portion in FIG. 5. FIG. 5 is a plan view of an inner layer conductor provided in the wiring board shown in FIG. 5. FIG. 5 is an enlarged view of a main portion IX including both straight portions in FIG. 5. FIG. 5 is a graph showing simulation results comparing insertion loss in a first wiring pattern between embodiment A and a conventional embodiment. FIG. 5 is a graph showing simulation results comparing reflection loss in a first wiring pattern between embodiment A and a conventional embodiment. FIG. 5 is a graph showing simulation results comparing insertion loss in a second wiring pattern between embodiment A and a conventional embodiment. FIG. 5 is a graph showing simulation results comparing reflection loss in a second wiring pattern between embodiment A and a conventional embodiment. FIG. 5 is a graph showing simulation results comparing insertion loss in a first wiring pattern between embodiment B and a conventional embodiment. 1 is a graph showing a simulation result comparing reflection loss in a first wiring pattern between embodiment B and a conventional embodiment; FIG. 2 is a graph showing a simulation result comparing insertion loss in a second wiring pattern between embodiment B and a conventional embodiment; FIG. 3 is a graph showing a simulation result comparing reflection loss in a second wiring pattern between embodiment B and a conventional embodiment; FIG. 4 is a perspective view of an electronic component storage package; FIG. 5 is an exploded perspective view of an electronic module;

[0009] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. However, for the sake of convenience, the figures referred to below are simplified views of the main components necessary for explaining the embodiments. Therefore, embodiments of the present disclosure may include optional components not shown in the figures referred to. Furthermore, the figures do not necessarily faithfully represent the dimensional ratios of the actual components. For convenience, directions are defined using the Cartesian coordinate system XYZ. The positive side of the X direction is the right side, the positive side of the Y direction is the front side, and the positive side of the Z direction is the top side. In this disclosure, "planar view" refers to a view from the top side of the wiring board (the positive side of the Z direction) and includes planar perspective views.

[0010] In the following description, expressions such as "constant," "orthogonal," "vertical," "parallel," or "equal" may be used. These expressions do not necessarily mean "constant," "orthogonal," "vertical," "parallel," or "equal" in their strict sense. In other words, these expressions allow for deviations due to, for example, manufacturing precision, installation precision, etc. Numerical ranges expressed using "to" include the numerical values ​​before and after the range as the lower and upper limits, respectively.

[0011] There is a demand for reducing insertion loss in differential signal wiring having a pair of signal conductors. This reduction in insertion loss is difficult, particularly when transmitting high frequencies of 50 GHz or higher. The technology disclosed in the aforementioned Patent Document 1 is not intended for application to differential signal wiring. Therefore, there is a demand for technology that enables the reduction of insertion loss in differential signal wiring.

[0012] The wiring board, electronic component storage package, and electronic module of the present disclosure enable a reduction in insertion loss. The wiring board, electronic component storage package, and electronic module of the present disclosure will be described in detail below.

[0013] 1 and 5 , a wiring board 10 according to the present disclosure includes an insulating base 11, one or more signal conductor pairs 12, and a plurality of ground conductors 14. The signal conductor pair 12 is located on the surface of the insulating base 11 and includes a pair of signal conductors 13. The signal conductor pair 12 is, for example, a differential signal wiring that transmits a differential signal. The ground conductors 14 are located on the surface of the insulating base 11 between the pair of signal conductors 13 and on both sides of the pair of signal conductors 13, spaced apart from the signal conductors 13. The plurality of ground conductors 14 may be electrically connected to each other. Furthermore, two or more of the plurality of ground conductors 14 may be electrically connected on the surface of the insulating base 11.

[0014] As will be described later, the wiring board 10 of the present disclosure has portions where the distance between the signal conductor 13 and the ground conductor 14 varies, but in other portions the distance between the signal conductor 13 and the ground conductor 14 is generally constant. The distance between the signal conductor 13 and the ground conductor 14 is, for example, 0.03 to 0.2 mm. Note that the "distance between the signal conductor 13 and the ground conductor 14" refers to the dimension between the signal conductor 13 and the ground conductor 14 in a direction perpendicular to the direction in which the signal conductor 13 extends.

[0015] The wiring board 10 of the present disclosure may have one or more double curved portions 121. In the present disclosure, "double curved portions 121" refers to portions where both signal conductors 13 of a pair of signal conductors 13 are curved portions 131 that are aligned with each other. In addition, the wiring board 10 of the present disclosure may have one or more single curved portions 122. In the present disclosure, "single curved portion 122" refers to a portion where one signal conductor 13 of a pair of signal conductors 13 is a straight portion 134 while the other signal conductor 13 is a curved portion 131.

[0016] The curved diameter of the curved portion 131 is, for example, 0.05 to 0.5 mm. When there are multiple curved portions 131, the curved diameters of the curved portions 131 may be the same as or different from one another. Note that the "curved diameter" refers to the radius of curvature.

[0017] In the present disclosure, the distances between the signal conductor 13 and the ground conductor 14 in both curved portions 121 are defined as follows: In both curved portions 121, the distance between the curved portion 131 with the smaller curved diameter and the ground conductor 14 closest to the curved portion 131 on the inside in the curved direction is defined as a "first distance d1." The distance between the curved portion 131 with the smaller curved diameter and the ground conductor 14 closest to the curved portion 131 on the outside in the curved direction is defined as a "second distance d2." The distance between the curved portion 131 with the larger curved diameter and the ground conductor 14 closest to the curved portion 131 on the inside in the curved direction is defined as a "third distance d3." The distance between the curved portion 131 with the larger curved diameter and the ground conductor 14 closest to the curved portion 131 on the outside in the curved direction is defined as a "fourth distance d4."

[0018] In the present disclosure, the distance between the signal conductor 13 and the ground conductor 14 in the one-side curved portion 122 is defined as follows. In the one-side curved portion 122, the distance between the curved portion 131 and the ground conductor 14 adjacent to the curved portion 131 on the inside in the curved direction is defined as a "first distance d1." The distance between the curved portion 131 and the ground conductor 14 adjacent to the curved portion 131 on the outside in the curved direction is defined as a "second distance d2." The distance between the straight portion 134 and the ground conductor 14 adjacent to the straight portion 134 on the curved portion 131 side is defined as a "third distance d3." The distance between the straight portion 134 and the ground conductor 14 adjacent to the straight portion 134 on the opposite side from the curved portion 131 is defined as a "fourth distance d4."

[0019] The "inner side in the bending direction" refers to the side where the center of curvature of the bending portion 131 exists. The "outer side in the bending direction" refers to the side opposite the inner side in the bending direction across the bending portion 131.

[0020] Furthermore, in the present disclosure, a curved portion 131 in which the distance between the nearest ground conductor 14 on the inside in the curved direction is narrower than the distance between the nearest ground conductor 14 on the outside in the curved direction is referred to as an "inner narrow-spaced curved portion 131a." Also, a curved portion 131 in which the distance between the nearest ground conductor 14 on the inside in the curved direction is equal to the distance between the nearest ground conductor 14 on the outside in the curved direction is referred to as an "equally-spaced curved portion on both sides 131b."

[0021] The wiring board 10 of the present disclosure may have one or more curved portions 121, each of which has a smaller curved diameter as an inner narrow-spaced curved portion 131a and a larger curved diameter as an equally-spaced curved portion 131b. In this case, the curved portion 131 with the smaller curved diameter has a first distance from the ground conductor 14 closest to it on the inside in the curved direction that is narrower than a second distance from the ground conductor 14 closest to it on the outside in the curved direction. Furthermore, the curved portion 131 with the larger curved diameter has a third distance from the ground conductor 14 closest to it on the inside in the curved direction that is equal to a fourth distance from the ground conductor 14 closest to it on the outside in the curved direction. The curved portion 131 with the smaller curved diameter of the two curved portions 121 is more likely to radiate electromagnetic waves outward in the curved direction due to its smaller curved diameter. On the other hand, in the inner narrow-spaced curved portion 131a, the spacing between the signal conductor 13 and the ground conductor 14 is narrower on the inner side in the curved direction, so that the electromagnetic coupling between the signal conductor 13 and the ground conductor 14 is stronger on the inner side in the curved direction than on the outer side in the curved direction. Therefore, if the curved portion 131 with a smaller curved diameter, which is more likely to electromagnetically radiate a high-frequency signal transmitted through the signal conductor 13 on the outer side in the curved direction, is the inner narrow-spaced curved portion 131a, electromagnetic radiation is efficiently reduced and insertion loss is likely to be reduced. Furthermore, if the curved portion 131 with a larger curved diameter, which is relatively less likely to emit electromagnetic radiation, is the bilateral equally-spaced curved portion 131b, impedance deviation is less likely to occur, and insertion loss due to impedance deviation is less likely to occur.

[0022] The wiring board 10 of the present disclosure may have one or more one-side curved portions 122, each having an inner narrow-space curved portion 131a. In this case, a first distance between the curved portion 131 and the ground conductor 14 closest to it on the inner side in the curved direction is narrower than a second distance between the curved portion 131 and the ground conductor 14 closest to it on the outer side in the curved direction. The straight portion 134 has a third distance between the curved portion 131 and the ground conductor 14 closest to it on the side opposite the curved portion 131. Due to its curvature, the curved portion 131 of the one-side curved portion 122 is prone to electromagnetic radiation outward in the curved direction. On the other hand, as described above, the inner narrow-space curved portion 131a provides stronger electromagnetic coupling between the signal conductor 13 and the ground conductor 14 on the inner side in the curved direction compared to the outer side in the curved direction. Therefore, if the curved portion 131, which is prone to electromagnetic radiation of high-frequency signals transmitted through the signal conductor 13 to the outside of the curved direction, is the inner narrow-spaced curved portion 131a, electromagnetic radiation is efficiently reduced, and insertion loss is likely to be reduced.

[0023] The wiring board 10 may have one or more signal conductor pairs 12 having both double curved portions 121 in which the curved portion 131 with a smaller curved diameter is an inner narrow-spaced curved portion 131a and the curved portion 131 with a larger curved diameter is an equally-spaced curved portion 131b on both sides, and a single curved portion 122 in which the curved portion 131 is an inner narrow-spaced curved portion 131a.

[0024] The wiring board 10 may have a signal conductor pair 12 having two curved portions 121 in which the curved portion 131 with a smaller curved diameter is an inner narrow-spaced curved portion 131 a and the curved portion 131 with a larger curved diameter is an equally-spaced curved portion 131 b on both sides, and a signal conductor pair 12 having a one-side curved portion 122 in which the curved portion 131 is an inner narrow-spaced curved portion 131 a.

[0025] The dashed lines in FIGS. 2, 3, 6 and 7 indicate the edge of a conventional curved portion 131, which is not cut out or protruded on the outside in the curved direction.

[0026] 2, 3, 6, and 7, the first interval d1 may be narrower than the second interval d2 by cutting out the outer side of the inner narrow-spaced curved portion 131a in the curved direction. This allows the first interval d1 to be narrower than the second interval d2 without interfering with the placement of the ground via conductor connected to the ground conductor 14. The cutout portion on the outer side of the inner narrow-spaced curved portion 131a in the curved direction becomes the cutout portion 132.

[0027] The width of the notch on the outer side in the bending direction of the inner narrow-gap curved portion 131a, i.e., the width of the notch 132, is, for example, 0.005 to 0.1 mm. Note that the "notch width" and the "width of the notch 132" refer to the dimension of the notch 132 in the direction perpendicular to the extension direction of the signal conductor 13.

[0028] When the outer side of the inner narrow-gap curved portion 131a in the curved direction is cut out, the first distance d1 may be equal to the third distance d3.

[0029] The first interval d1 may be narrower than the second interval d2 due to the inward protrusion of the inner narrow-spaced curved portion 131a in the curvature direction. This allows the first interval d1 to be narrower than the second interval d2 without interfering with the arrangement of the ground via conductor connected to the ground conductor 14. The protruding portion of the inner narrow-spaced curved portion 131a in the curvature direction serves as a protrusion 133. The first interval d1 may be narrower than the second interval d2 due to the inward protrusion of the inner narrow-spaced curved portion 131a in the curvature direction without cutting out the outer side of the inner narrow-spaced curved portion 131a in the curvature direction.

[0030] The width of the inner narrow-gap curved portion 131a projecting inward in the curved direction, i.e., the width of the protruding portion 133, is, for example, 0.005 to 0.1 mm. Note that the "protruding width" and the "width of the protruding portion 133" refer to the dimension of the protruding portion 133 in a direction perpendicular to the direction in which the signal conductor 13 extends.

[0031] 6 and 7 , the first interval d1 may be narrower than the second interval d2 by notching the outer side of the inner narrow-spaced curved portion 131a in the curved direction and further protruding the inner side of the inner narrow-spaced curved portion 131a in the curved direction. This allows the first interval d1 to be narrower than the second interval d2 without making the width of the inner narrow-spaced curved portion 131a too small, making it easier to adjust the impedance.

[0032] When the outer side of the inner narrow-spaced curved portion 131a in the curved direction is notched and the inner side of the inner narrow-spaced curved portion 131a protrudes in the curved direction, the first distance d1 may be narrower than the third distance d3, which makes it easier to adjust the impedance at the inner narrow-spaced curved portion 131a.

[0033] When the inner narrow-spaced curved portion 131 a has a notch on the outer side in the curved direction and the inner narrow-spaced curved portion 131 a protrudes inward in the curved direction, the protruding width on the inner side in the curved direction may be narrower than the notched width on the outer side in the curved direction. By making the protruding width on the inner side in the curved direction narrower than the notched width on the outer side in the curved direction, the possibility of a short circuit between the signal conductor 13 and the ground conductor 14 on the inner side in the curved direction is reduced.

[0034] The first interval d1 may be narrower than the second interval d2 by cutting out the ground conductor 14 adjacent to the outer side in the curved direction of the inner narrow-spaced curved portion 131a. This allows the first interval d1 to be narrower than the second interval d2 while maintaining a constant width of the signal conductor 13. This makes it easier to maintain a constant width of the signal conductor 13 during the manufacturing process, thereby reducing the possibility of manufacturing variations in the high-frequency characteristics of the wiring board 10. When the ground conductor 14 adjacent to the outer side in the curved direction of the inner narrow-spaced curved portion 131a is cut out, the width of the cutout in the ground conductor 14 is, for example, 0.005 to 0.1 mm.

[0035] When the ground conductor 14 adjacent to the outer side of the inner narrow-gap curved portion 131a in the curved direction is cut out, the first interval d1 may be equal to the third interval d3.

[0036] The first interval d1 may be narrower than the second interval d2 due to the protrusion of the ground conductor 14 located close to the inner narrow-gap curved portion 131a in the curved direction. In this case, the protruding width of the ground conductor 14 is, for example, 0.005 to 0.1 mm.

[0037] The first interval d1 may be narrower than the second interval d2 by notching the ground conductor 14 adjacent to the outer side of the curved inner narrow-spaced curved portion 131a in the curved direction and by further protruding the ground conductor 14 adjacent to the inner side of the curved inner narrow-spaced curved portion 131a in the curved direction. This allows the first interval d1 to be narrower than the second interval d2 while maintaining a constant width of the signal conductor 13. This makes it easier to maintain a constant width of the signal conductor 13 during the manufacturing process, thereby reducing the possibility of manufacturing variations in the high-frequency characteristics of the wiring substrate 10.

[0038] The means for making the first distance d1 narrower than the second distance d2 is not limited to the means described above. The structure in which the first distance d1 is narrower than the second distance d2 may be realized by any one of a notch in the signal conductor 13, a protrusion in the signal conductor 13, a notch in the ground conductor 14, and a protrusion in the ground conductor 14 alone, or by a combination of two or more of these.

[0039] 3 and 7 , the signal conductor pair 12 may have a plurality of consecutive one-sided curved portions 122 each having an inner narrow-spaced curved portion 131 a, with the inner narrow-spaced curved portions 131 a positioned consecutively while changing their curvature direction. In this case, the multiple one-sided curved portions 122 share a single straight portion 134. When curved portions 131 occur in the equal-length wiring design of differential signal wiring, the wiring substrate 10 can be made smaller by providing multiple one-sided curved portions 122 each having a small curvature diameter, rather than providing one one-sided curved portion 122 with a large curvature diameter.

[0040] The wiring substrate 10 may have multiple inner narrow-spaced curved portions 131a with different curvature diameters. In this case, the difference between the first interval d1 and the second interval d2 may be larger for inner narrow-spaced curved portions 131a with smaller curvature diameters. The larger the difference between the first interval d1 and the second interval d2, the more likely it is that electromagnetic radiation of a high-frequency signal transmitted through the signal conductor 13 will be reduced. Therefore, if the difference between the first interval d1 and the second interval d2 is larger for inner narrow-spaced curved portions 131a with smaller curvature diameters, electromagnetic radiation is significantly reduced in the inner narrow-spaced curved portions 131a with smaller curvature diameters, which are relatively susceptible to electromagnetic radiation, thereby efficiently reducing insertion loss. Furthermore, in inner narrow-spaced curved portions 131a with larger curvature diameters, which are relatively less susceptible to electromagnetic radiation, the degree of change in the wiring shape is reduced, making it easier to adjust impedance. Multiple inner narrow-spaced curved portions 131a with different curvature diameters may be included in the same signal conductor 13 or in different signal conductors 13.

[0041] The width of each of the pair of signal conductors 13 in one signal conductor pair 12 is usually constant, but may include non-constant portions, such as portions having cutouts 132 and / or protrusions 133. The width of the signal conductors 13 is, for example, 0.03 to 0.2 mm. The widths of the portions of the multiple signal conductors 13 that do not have cutouts 132 or protrusions 133 may be the same or different. If the widths of the portions of the multiple signal conductors 13 that do not have cutouts 132 or protrusions 133 are the same, the high-frequency characteristics of each signal conductor 13 tend to be constant.

[0042] The portions of a pair of signal conductors 13 where the straight portions 134 are parallel to each other are referred to as "two straight portions 123." The distance between one signal conductor 13 in each straight portion 123 and the ground conductor 14 adjacent to one side of the signal conductor 13 is referred to as the "fifth distance d5." The distance between the signal conductor 13 and the ground conductor 14 adjacent to the other side of the signal conductor 13 is referred to as the "sixth distance d6." The distance between the other signal conductor 13 in each straight portion 123 and the ground conductor 14 adjacent to one side of the signal conductor 13 is referred to as the "seventh distance d7." The distance between the signal conductor 13 and the ground conductor 14 adjacent to the other side of the signal conductor 13 is referred to as the "eighth distance d8." In this case, as shown in FIG. 9 , the fifth distance d5, the sixth distance d6, the seventh distance d7, and the eighth distance d8 may all be equal. This makes it easier to adjust the impedance and also makes it easier to reduce the insertion loss.

[0043] As shown in Figures 4 and 8, the wiring board 10 may include an inner layer conductor 15 located within the insulating base 11. This strengthens the ground potential. In the embodiment illustrated in Figures 4 and 8, the inner layer conductor 15 is located below the signal conductor 13 and the ground conductor 14 (on the negative side in the Z direction). In Figures 4 and 8, the signal conductor pair 12 located above the inner layer conductor 15 (on the positive side in the Z direction) is indicated by dashed lines. The inner layer conductor 15 and the ground conductor 14 may be electrically connected by a plurality of ground via conductors.

[0044] As shown in Figures 4 and 8, the inner layer conductor 15 may have a plurality of openings 151. In addition, in a plan view, the plurality of openings 151 may overlap the signal conductor 13 and be positioned side by side along the signal conductor 13. This ensures a grounded state in the high-frequency characteristics of the wiring board 10 while reducing a decrease in impedance. The shape of the openings 151 is not limited to a circular shape as shown in Figures 4 and 8, but may be an elliptical shape, a polygonal shape, or the like. In addition, the shapes of the plurality of openings 151 may be the same or different from one another.

[0045] 4 and 8 , the openings 151 may be positioned so as not to overlap the inner narrow-spaced curved portions 131a of the signal conductor 13 in plan view. The inner narrow-spaced curved portions 131a tend to have high impedance. In particular, when the width of the inner narrow-spaced curved portions 131a is narrower than the width of the portions of the signal conductor 13 other than the inner narrow-spaced curved portions 131a, the impedance of the inner narrow-spaced curved portions 131a tends to be high. In contrast, if the openings 151, which have the effect of increasing impedance, are positioned so as not to overlap the inner narrow-spaced curved portions 131a of the signal conductor 13, the possibility of the impedance of the inner narrow-spaced curved portions 131a becoming too high is reduced.

[0046] The wiring board 10 may have multiple inner layer conductors 15 in the insulating base 11 at different positions in the Z direction. In this case, each inner layer conductor 15 may have an opening 151 at the same position in a plan view. In other words, the opening 151 may be located across the multiple inner layer conductors 15 at a position that overlaps with the signal conductor 13 in a plan view.

[0047] 10A to 13B show the results of a simulation demonstrating the effects of the wiring board 10 of the present disclosure. In this simulation, the wiring pattern of the signal conductor pair 12 connecting the third port P3 and the fourth port P4 in FIGS. 1 and 5 and having both curved portions 121 is defined as the first wiring pattern. The wiring pattern of the signal conductor pair 12 connecting the first port P1 and the second port P2 in FIGS. 1 and 5 and having one curved portion 122 is defined as the second wiring pattern. As shown in FIG. 1 , among the embodiments of the present disclosure, an embodiment in which the curved portion 131 has a cutout portion 132 but does not have a protrusion 133 is defined as embodiment A. As shown in FIG. 5 , among the embodiments of the present disclosure, an embodiment in which the curved portion 131 has a cutout portion 132 and a protrusion 133 is defined as embodiment B. As a comparative example, a conventional configuration is one in which the curved portion 131 does not have the notch portion 132 and the protruding portion 133, and the first distance d1 and the second distance d2 are equal.

[0048] 10A to 13B show that the wiring board 10 of the present disclosure has reduced insertion loss compared to conventional wiring boards. This reduction in insertion loss is particularly noticeable in the high frequency range of 100 GHz or higher, particularly around 140 GHz.

[0049] 10A to 13B, it can be seen that the second wiring pattern having one curved portion 122 has a greater effect of reducing insertion loss than the first wiring pattern having both curved portions 121. This is thought to be because the smaller the curved diameter of the curved portion 131, the more likely it is that electromagnetic radiation of high-frequency signals transmitted through the signal conductor 13 occurs, and this electromagnetic radiation is significantly reduced when the curved portion 131 is the inner narrow-gap curved portion 131a.

[0050] 10A to 13B, it can be seen that the wiring board 10 of the present disclosure does not have a worsening of the reflection loss compared to the conventional wiring board. From this, it can be said that the wiring board 10 of the present disclosure can reduce the insertion loss without worsening the reflection loss.

[0051] The material of the insulating base 11 may be a ceramic sintered body such as an aluminum oxide sintered body, an aluminum nitride sintered body, a silicon carbide sintered body, a mullite sintered body, or a glass ceramic. The material of the insulating base 11 may also be a resin such as an epoxy resin, a polyimide, or a liquid crystal polymer. By using, for example, a polyimide or a liquid crystal polymer as the material of the insulating base 11, the wiring board 10 can also be used as a flexible printed circuit board (FPC) or a printed circuit board (PCB).

[0052] The material of the signal conductor 13, the ground conductor 14, and the inner layer conductor 15 is, for example, a metal such as tungsten, molybdenum, manganese, copper, gold, or silver, or an alloy thereof.

[0053] When the insulating base 11 is made of an aluminum oxide sintered body and the signal conductors 13, ground conductors 14, and inner-layer conductors 15 are made of tungsten metallized layers, the wiring board 10 can be fabricated, for example, as follows: First, the raw material powder for the insulating base 11 is mixed with an organic solvent and an organic binder to form a slurry. The raw material powder for the insulating base 11 mainly comprises aluminum oxide powder and a powder of silicon oxide or other sintering aid components. Next, the slurry is formed into a sheet using a forming method such as a doctor blade method or a lip coater method to form a ceramic green sheet. Next, tungsten powder is mixed with an organic solvent and an organic binder to form a metal paste. The metal paste is then printed in a predetermined position on the ceramic green sheet using a method such as screen printing. If necessary, multiple ceramic green sheets are stacked to form a laminate. The laminate is then fired at a temperature of approximately 1300°C to 1600°C. Furthermore, the ground via conductors can be formed by forming through-holes at predetermined positions in the ceramic green sheet prior to printing the metal paste, filling the through-holes with the same metal paste as described above, and firing the sheet together with the ceramic green sheet. A nickel film of approximately 1 to 10 μm and a gold film of approximately 0.1 to 3 μm may be formed in this order on the surfaces of the signal conductor 13 and the ground conductor 14. This protects the surfaces and improves bonding with brazing filler metals, solder, etc.

[0054] [Package for storing electronic components] As shown in FIG. 14 , the package for storing electronic components 20 may include a substrate 21, a frame body 22 positioned on the substrate 21, and a wiring board 10 joined to the frame body 22.

[0055] The substrate 21 is, for example, a rectangular plate-like member. The frame 22 is a frame-like member provided in a position that surrounds the mounting area for the electronic component 32 in a plan view. As shown in Fig. 14, the frame 22 may have a light-transmitting portion 23 for transmitting and receiving light between the inside and outside of the electronic component housing package 20.

[0056] The substrate 21 and the frame 22 may be configured, for example, by stacking a plurality of insulating substrates. Examples of insulating substrates that can be used include ceramic sintered bodies such as aluminum oxide sintered bodies, aluminum nitride sintered bodies, silicon carbide sintered bodies, mullite sintered bodies, and glass ceramics. The material of the substrate 21 and the frame 22 may be metal. Examples of metals include copper, tungsten, molybdenum, iron, nickel, or cobalt, or alloys thereof. Specific examples of alloys include copper-tungsten alloy, copper-molybdenum alloy, and iron-nickel-cobalt alloy. The material of the substrate 21 and the material of the frame 22 may be the same as or different from each other.

[0057] The frame 22 may be molded integrally with the insulating base 11 of the wiring board 10. If the frame 22 and the insulating base 11 are made of the same material, they can be easily molded integrally.

[0058] 14 , the electronic component storage package 20 may include a seal ring 24 located on the upper surface of the frame 22. The seal ring 24 functions as a sealant when the lid 34 is used to hermetically seal the electronic component storage package 20 after the electronic component 32 is mounted on the electronic component storage package 20. The seal ring 24 may be formed by joining a frame-shaped metal plate containing an Fe—Ni alloy, an Fe—Ni—Co alloy, or the like, to a frame formed from a conductive paste containing a high-melting-point metal such as tungsten or molybdenum, using a brazing material or the like.

[0059] [Electronic Module] As shown in FIG. 15 , an electronic module 30 may include an electronic component storage package 20, an electronic component 32 located on a substrate 21 and electrically connected to the signal conductor pair 12, and a lid 34 located on a frame 22.

[0060] The electronic component 32 may be located on a mount member 31 provided on the substrate 21. The electronic component 32 may be electrically connected to the signal conductor pair 12 by a connecting member such as a bonding wire 33. The electronic component 32 is, for example, an electronic component that inputs or outputs a high-frequency signal (e.g., a frequency band of about 10 GHz or higher) related to optical communication. Specific examples of the electronic component 32 include a light-emitting element and a light-receiving element. However, these are merely examples, and the electronic component 32 is not limited to the above.

[0061] The lid 34 is, for example, a plate-shaped member. The lid 34 may be made of any material that can reduce the intrusion of foreign matter such as moisture and fine particles into the interior (cavity) of the electronic module 30. The lid 34 may be made of the same metal material as the seal ring 24, or may be made of the same material as the substrate 21 and the frame 22, but processed and molded into a plate shape.

[0062] Further embodiments of the wiring board, electronic component storage package, and electronic module according to the present disclosure will be described below.

[0063] (1) One embodiment of a wiring board according to the present disclosure comprises: an insulating base; one or more signal conductor pairs, each of which is located on the surface of the insulating base and has a pair of signal conductors; and a plurality of ground conductors, each of which is located on the surface of the insulating base between the pair of signal conductors and on both sides of the pair of signal conductors, with a gap between them. In the pair of signal conductors, each of the signal conductors has one or more curved portions that are curved along each other, and in at least one of the curved portions, the curved portion with a smaller curved diameter is an inner narrow-spaced curved portion in which a first gap between the adjacent ground conductor on the inside in the curved direction is narrower than a second gap between the adjacent ground conductor on the outside in the curved direction, and the curved portion with a larger curved diameter is a bilateral equally-spaced curved portion in which a third gap between the adjacent ground conductor on the inside in the curved direction is equal to a fourth gap between the adjacent ground conductor on the outside in the curved direction.

[0064] (2) One embodiment of a wiring board according to the present disclosure comprises: an insulating base; one or more signal conductor pairs, each of which is located on the surface of the insulating base and has a pair of signal conductors; and a plurality of ground conductors, each of which is located on the surface of the insulating base between and on both sides of the pair of signal conductors and spaced apart from the signal conductors, wherein the pair of signal conductors has one or more one-sided curved portions, in which one signal conductor is a straight portion while the other signal conductor is a curved portion, and in at least one of the one-sided curved portions, the curved portion is an inner narrow-spaced curved portion in which a first gap between the adjacent ground conductor on the inside in the curved direction and the adjacent ground conductor on the outside in the curved direction is narrower than a second gap between the adjacent ground conductor on the outside in the curved direction, and the straight portion has a third gap between the adjacent ground conductor on the side of the curved portion and the adjacent ground conductor on the opposite side from the curved portion,

[0065] (3) One embodiment of the wiring board according to the present disclosure is the wiring board of (1) or (2) above, wherein the first interval is narrower than the second interval by cutting out the outer side of the inner narrow interval curved portion in the curved direction.

[0066] (4) One embodiment of the wiring board according to the present disclosure is the wiring board according to (3) above, in which the first interval is equal to the third interval.

[0067] (5) One embodiment of the wiring board according to the present disclosure is the wiring board of (3) above, wherein the first interval is narrower than the second interval because the inner narrow interval curved portion further protrudes inward in the curved direction.

[0068] (6) One embodiment of the wiring board according to the present disclosure is the wiring board according to (5) above, in which the first gap is narrower than the third gap.

[0069] (7) One embodiment of the wiring board according to the present disclosure is the wiring board of (5) or (6) above, wherein the width of the protruding portion on the inner side in the curvature direction is narrower than the width of the notched portion on the outer side in the curvature direction.

[0070] (8) One embodiment of the wiring board according to the present disclosure is the wiring board of any one of (1) to (7) above, wherein the first interval is narrower than the second interval by cutting out the ground conductor that is close to the outer side of the inner narrow interval curved portion in the curved direction.

[0071] (9) One embodiment of the wiring board according to the present disclosure is the wiring board of (8) above, wherein the first interval is narrower than the second interval because the ground conductor adjacent to the inner narrow interval curved portion protrudes further in the curved direction.

[0072] (10) One embodiment of the wiring board according to the present disclosure is the wiring board of (2) above, which has a plurality of consecutive one-sided curved portions each having the inner narrow-spaced curved portion such that the inner narrow-spaced curved portions are consecutively positioned while changing their curvature direction.

[0073] (11) One embodiment of the wiring board according to the present disclosure is the wiring board of any one of (1) to (10) above, which has a plurality of the inner narrow-spaced curved portions with different curvature diameters, and the smaller the curvature diameter of the inner narrow-spaced curved portion, the greater the difference between the first interval and the second interval.

[0074] (12) One embodiment of the wiring board according to the present disclosure is the wiring board of any one of (1) to (11) above, further comprising an inner layer conductor located within the insulating base, the inner layer conductor having a plurality of openings, and in a plan view, the plurality of openings overlap with the signal conductor and are positioned in a line along the signal conductor.

[0075] (13) One embodiment of the wiring board according to the present disclosure is the wiring board of (12) above, wherein, in a plan view, the plurality of openings are positioned so as not to overlap the inner narrow-spaced curved portions of the signal conductors.

[0076] (14) One embodiment of an electronic component storage package according to the present disclosure comprises a substrate, a frame body positioned on the substrate, and a wiring board according to any one of (1) to (13) above joined to the frame body.

[0077] (15) One embodiment of an electronic module according to the present disclosure comprises: an electronic component storage package according to (14) above; an electronic component located on the substrate and electrically connected to the signal conductor pair; and a lid located on the frame.

[0078] In addition, the details shown in the above embodiments can be modified as appropriate without departing from the spirit of the present disclosure. The scope of the present disclosure includes the scope of the invention described in the claims and its equivalents. Various combinations of the embodiments are not limited to the examples of the above embodiments. Furthermore, combinations of the embodiments with each other are also possible.

[0079] 10 wiring substrate 11 insulating base 12 signal conductor pair 121 both curved portions 122 one-side curved portion 123 both straight portions 13 signal conductor 131a inner narrowly spaced curved portion 131b both equally spaced curved portions 132 notch portion 133 protrusion 134 straight portion 14 ground conductor 15 inner layer conductor 151 opening d1 first interval d2 second interval d3 third interval d4 fourth interval d5 fifth interval d6 sixth interval d7 seventh interval d8 eighth interval P1 first port P2 second port P3 third port P4 fourth port 20 electronic component storage package 21 substrate 22 frame 23 light-transmitting portion 24 seal ring 30 electronic module 31 mounting member 32 electronic component 33 bonding wire 34 Lid

Claims

1. A wiring board comprising: an insulating base; one or more signal conductor pairs, each of which is located on the surface of the insulating base and has a pair of signal conductors; and a plurality of ground conductors, each of which is located on the surface of the insulating base between the pair of signal conductors and on both sides of the pair of signal conductors, with a gap between them, wherein each of the signal conductors in the pair has one or more curved portions that curve along each other, and in at least one of the curved portions, the curved portion with a smaller curved diameter is an inner narrow-spaced curved portion in which a first gap between the adjacent ground conductor on the inside in the curved direction is narrower than a second gap between the adjacent ground conductor on the outside in the curved direction, and the curved portion with a larger curved diameter is an equally-spaced curved portion on both sides in which a third gap between the adjacent ground conductor on the inside in the curved direction is equal to a fourth gap between the adjacent ground conductor on the outside in the curved direction.

2. A wiring board comprising: an insulating base; one or more signal conductor pairs, each having a pair of signal conductors, located on the surface of the insulating base; and a plurality of ground conductors located on the surface of the insulating base between and on both sides of the pair of signal conductors, with a gap between them, wherein the pair of signal conductors has one or more one-sided curved portions, one of which is a straight portion while the other is a curved portion, and in at least one of the one-sided curved portions, the curved portion is an inner narrow-spaced curved portion in which a first gap between the adjacent ground conductor on the inside in the curved direction and the other ground conductor on the outside in the curved direction is narrower than a second gap between the adjacent ground conductor on the outside in the curved direction, and the straight portion has a third gap between the adjacent ground conductor on the side of the curved portion and the ground conductor, and a fourth gap between the adjacent ground conductor on the opposite side of the curved portion.

3. The wiring board according to claim 1 or 2, wherein the first interval is narrower than the second interval by cutting out an outer side in the curved direction of the inner narrow interval curved portion.

4. The wiring board according to claim 3, wherein the first interval is equal to the third interval.

5. The wiring board according to claim 3, wherein the first interval is narrower than the second interval by the inner narrow interval curved portion further protruding inward in the curved direction.

6. The wiring board according to claim 5, wherein the first interval is narrower than the third interval.

7. The wiring board according to claim 5 or 6, wherein the width of the protruding portion on the inner side in the curved direction is narrower than the width of the notched portion on the outer side in the curved direction.

8. A wiring board according to any one of claims 1 to 7, wherein the first interval is narrower than the second interval by cutting out the ground conductor adjacent to the outer side in the curved direction of the inner narrow-interval curved portion.

9. The wiring board according to claim 8, wherein the first interval is narrower than the second interval because the ground conductor protrudes from the inner narrow interval curved portion in the direction of curvature.

10. The wiring board according to claim 2, wherein the one-side curved portion having the inner narrow-spaced curved portion is provided in a plurality of successive positions such that the inner narrow-spaced curved portions are positioned successively while changing their curved direction.

11. A wiring board according to any one of claims 1 to 10, comprising a plurality of inner narrow-spaced curved portions having different curved diameters, wherein the smaller the curved diameter of the inner narrow-spaced curved portion, the greater the difference between the first interval and the second interval.

12. The wiring board according to any one of claims 1 to 11, further comprising an inner layer conductor located within said insulating base, said inner layer conductor having a plurality of openings, wherein in a plan view, said plurality of openings overlap with said signal conductor and are positioned in a row along said signal conductor.

13. The wiring board according to claim 12, wherein, in a plan view, the plurality of openings are positioned so as not to overlap the inner narrow-spaced curved portions of the signal conductors.

14. A package for storing electronic components, comprising: a substrate; a frame body positioned on said substrate; and a wiring board according to any one of claims 1 to 13 joined to said frame body.

15. An electronic module comprising: the package for storing electronic components according to claim 14; an electronic component located on the substrate and electrically connected to the signal conductor pairs; and a lid located on the frame.

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