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

Abstract

A first signal conductor has, in order from a first-side-surface side of an insulating substrate: a first portion that has a constant width; a second portion that has a constant width and is narrower than the first portion; and a third portion that has a constant width, is narrower than the first portion, and is wider than the second portion. A second signal conductor has, in order from the first-side-surface side: a fourth portion that has a constant width; a fifth portion that has a constant width and is narrower than the fourth portion; and a sixth portion that has a constant width, is narrower than the fourth portion, and is wider than the fifth portion. A wiring board has: a first region in which a first ground conductor, the first signal conductor, the second signal conductor, and a second ground conductor are aligned, and which is positioned closer to the first side surface than a third ground conductor; and a second region which is positioned closer to the inner side of the insulating substrate than the first region, and in which the first ground conductor, the first signal conductor, the third ground conductor, the second signal conductor, and the second ground conductor are aligned.

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] For example, as disclosed in Patent Document 1, a transmission line is known that is configured with a pair of signal conductors and ground conductors located therebetween and on both sides.

[0003] International Publication No. 2023 / 100964

[0004] A wiring board according to the present disclosure comprises an insulating base, a first signal conductor, a second signal conductor, a first ground conductor, a second ground conductor, and a third ground conductor. The insulating base has a first side surface. The first signal conductor and the second signal conductor extend from the first side surface toward the inside of the insulating base. The first ground conductor is located on the opposite side of the second signal conductor with the first signal conductor in between. The second ground conductor is located on the opposite side of the second signal conductor with the second signal conductor in between. The third ground conductor is located between the first and second signal conductors. The first ground conductor, the first signal conductor, the third ground conductor, the second signal conductor, and the second ground conductor are each located on the insulating base at intervals from one another. The first signal conductor has a first portion, a second portion, and a third portion. The first portion has a constant width from the first side surface side. The second portion has a constant width from the first side surface side and is narrower than the first portion. The third portion has a constant width, narrower than the first portion and wider than the second portion, in the order from the first side surface side. The second signal conductor has a fourth portion, a fifth portion, and a sixth portion. The fourth portion has a constant width, in the order from the first side surface side. The fifth portion has a constant width, narrower than the fourth portion, in the order from the first side surface side. The sixth portion has a constant width, narrower than the fourth portion and wider than the fifth portion, in the order from the first side surface side. The wiring board according to the present disclosure has a first region and a second region. In the first region, the first ground conductor, the first signal conductor, the second signal conductor, and the second ground conductor are aligned in a first direction along the first side surface, and are located closer to the first side surface than the third ground conductor. In the second region, the first ground conductor, the first signal conductor, the third ground conductor, the second signal conductor, and the second ground conductor are aligned in the first direction, further inward of the insulating base than the first region.

[0005] Furthermore, an electronic component storage package according to the present disclosure includes a substrate, a frame, and a wiring substrate, the frame being positioned on the substrate, and the wiring substrate being bonded to the frame.

[0006] Furthermore, an electronic module according to the present disclosure includes an electronic component storage package, an electronic component, and a lid. The electronic component is located on a substrate and electrically connected to a first signal conductor and a second signal conductor. The lid is located on a frame.

[0007] 5 is a plan view of a wiring board according to an embodiment of the present disclosure; FIG. 6 is an enlarged view of a main part A in FIG. 1; FIG. 7 is an enlarged view of another embodiment of the main part A; FIG. 8 is an enlarged view of another embodiment of the main part A; FIG. 9 is a plan view of a first inner-layer ground conductor; FIG. 10 is an enlarged view of a main part B in FIG. 5; FIG. 11 is a graph showing simulation results of return loss; FIG. 12 is a graph showing simulation results of insertion loss; FIG. 13 is a plan view showing a conventional embodiment; FIG. 14 is a perspective view of an electronic component storage package; FIG. 15 is an exploded perspective view of an electronic module;

[0008] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. However, for the sake of convenience, the drawings below show simplified views of the main components necessary for explaining the embodiments. Therefore, the embodiments of the present disclosure may include any components not shown in the drawings. Furthermore, the drawings do not necessarily faithfully represent the dimensional proportions of the actual components.

[0009] For convenience, directions are defined using an orthogonal coordinate system XYZ, with the positive side in the Z direction being the upper side. In this disclosure, "planar view" refers to a view from the upper side of the wiring board (the positive side in the Z direction), and includes a planar perspective view.

[0010] In the following description, expressions such as "constant," "orthogonal," "vertical," "parallel," and "equal" may be used. These expressions are not limited to the strict meaning of "constant," "orthogonal," "vertical," "parallel," and "equal," respectively, and allow for deviations due to, for example, manufacturing precision and installation precision. Numerical ranges expressed using "to" include the numerical values ​​written before and after as the lower and upper limits, respectively.

[0011] In recent years, crosstalk noise between signal conductors has become more likely to occur due to factors such as higher signal frequencies and higher wiring density. A similar trend is observed in differential transmission lines, which are composed of a pair of signal conductors that transmit signals of opposite phases. Furthermore, reflection loss is likely to occur at the external terminal junctions of the signal conductors due to factors such as changes in conductor width.

[0012] The wiring board, electronic component storage package, and electronic module of the present disclosure can achieve good crosstalk characteristics and reflection characteristics.

[0013] [Wiring Board] As shown in Figure 2 and other figures, the wiring board 10 includes an insulating base 11, a first signal conductor 12, a second signal conductor 13, a first ground conductor 14, a second ground conductor 15, and a third ground conductor 16. The insulating base 11 has a first side surface 111. The first signal conductor 12 and the second signal conductor 13 extend from the first side surface 111 toward the inside of the insulating base 11 (the negative side in the Y direction). The first ground conductor 14 is located on the opposite side of the second signal conductor 13 with the first signal conductor 12 in between. The second ground conductor 15 is located on the opposite side of the second signal conductor 13 with the second signal conductor 13 in between. The third ground conductor 16 is located between the first signal conductor 12 and the second signal conductor 13. The first ground conductor 14, the first signal conductor 12, the third ground conductor 16, the second signal conductor 13, and the second ground conductor 15 are located on the insulating base 11 at intervals from one another.

[0014] The first signal conductor 12 has, in order from the first side surface 111 side, a first portion 121, a second portion 122, and a third portion 123. The width of the first portion 121 is constant. The width of the second portion 122 is constant and narrower than the first portion 121. The width of the third portion 123 is constant and narrower than the first portion 121 and wider than the second portion 122. The second signal conductor 13 has, in order from the first side surface 111 side, a fourth portion 131, a fifth portion 132, and a sixth portion 133. The width of the fourth portion 131 is constant. The width of the fifth portion 132 is constant and narrower than the fourth portion 131. The width of the sixth portion 133 is constant and narrower than the fourth portion 131 and wider than the fifth portion 132. The "width" of each portion of the signal conductor is the dimension of the signal conductor in a direction perpendicular to the direction in which the signal conductor extends in the XY plane.

[0015] The first portion 121 and the fourth portion 131 can be used as external terminal connection portions. Examples of external terminals that can be connected to the first portion 121 and the fourth portion 131 include bonding wires, lead terminals, terminals of flexible printed circuits (FPCs), and terminals of flip-chip mounted electronic components.

[0016] The first portion 121 can be used as an external terminal connection portion, and therefore has a wider width and a larger capacitance component than other portions of the first signal conductor 12. When the third portion 123 is used as the reference for impedance adjustment, the second portion 122, which has a narrower width and a larger inductance component, is located between the first portion 121 and the third portion 123, thereby facilitating appropriate adjustment of the impedance of the first signal conductor 12. The same applies to the second signal conductor 13. When the sixth portion 133 is used as the reference for impedance adjustment, the fifth portion 132, which has a larger inductance component, is located between the sixth portion 133 and the fourth portion 131, which has a larger capacitance component, thereby facilitating appropriate adjustment of the impedance of the second signal conductor 13. The ease of adjusting the impedance of the first signal conductor 12 and the second signal conductor 13 improves the reflection characteristics of the wiring board 10.

[0017] 2 to 4 , the wiring board 10 has a first region A1 and a second region A2. The first region A1 is a region in which the first ground conductor 14, the first signal conductor 12, the second signal conductor 13, and the second ground conductor 15 are aligned in a first direction (X direction) along the first side surface 111, and is located closer to the first side surface 111 than the third ground conductor 16. The second region A2 is located more inward (on the negative side of the Y direction) of the insulating base 11 than the first region A1, and is a region in which the first ground conductor 14, the first signal conductor 12, the third ground conductor 16, the second signal conductor 13, and the second ground conductor 15 are aligned in the first direction (X direction).

[0018] The wiring structure of the second region A2 is a GSGSG structure in which a ground conductor, a signal conductor, a ground conductor, a signal conductor, and a ground conductor are arranged in this order. The GSGSG structure has excellent high-frequency characteristics because it is easy to reduce insertion loss due to radiation and the like at portions where the path difference is shifted, such as curved portions of the wiring. On the other hand, the wiring structure of the first region A1 is a GSSG structure in which a ground conductor, a signal conductor, a signal conductor, and a ground conductor are arranged in this order. The GSSG structure has excellent crosstalk characteristics because of strong differential coupling between signals transmitted by the two signal conductors. The first region A1 may include a first portion 121 and a fourth portion 131 that can be used as external terminal connection portions. Because signals are prone to leak between channels at the external terminal connection portions, if this external terminal connection portion has a GSSG structure, crosstalk characteristics are efficiently improved. Therefore, in the wiring board 10 of the present disclosure, the second region A2, which has a GSGSG structure, is located inside the insulating base 11, and the first region A1, which has a GSSG structure, is located outside of that, thereby maintaining the high-frequency characteristics of reflection loss and insertion loss while also improving the crosstalk characteristics at the external terminal connection portion.

[0019] The width of the first portion 121 and the width of the fourth portion 131 are, for example, 0.05 to 0.5 mm and may be the same or different. The width of the second portion 122 and the width of the fifth portion 132 are, for example, 0.01 to 0.3 mm and may be the same or different. The width of the third portion 123 and the width of the sixth portion 133 are, for example, 0.02 to 0.4 mm and may be the same or different.

[0020] The width of the first ground conductor 14 and the width of the second ground conductor 15 are, for example, 0.05 mm or more at their narrowest portions. The width of the third ground conductor 16 is, for example, 0.05 to 0.5 mm.

[0021] 2 and 3 , the first signal conductor 12 may have a first notch 127 on the side where the first ground conductor 14 is located. In this case, the second portion 122 may have a narrower width than the third portion 123 due to the first notch 127. The second signal conductor 13 may have a second notch 137 on the side where the second ground conductor 15 is located. In this case, the fifth portion 132 may have a narrower width than the sixth portion 133 due to the second notch 137. This makes it easier to adjust the impedance of the capacitance component, which tends to be large in the first portion 121 and the fourth portion 131, in the second portion 122 and the fifth portion 132, and ultimately makes it easier to adjust the characteristic impedance in the third portion 123 and the sixth portion 133.

[0022] 2 , the first edge 126 of the first signal conductor 12 on the side where the second signal conductor 13 is located may be linear from the second portion 122 to the third portion 123. The second edge 136 of the second signal conductor 13 on the side where the first signal conductor 12 is located may be linear from the fifth portion 132 to the sixth portion 133. This ensures that when the portion of the first edge 126 from the second portion 122 to the third portion 123 and the portion of the second edge 136 from the fifth portion 132 to the sixth portion 133 are parallel to each other, the distance between them is constant. This makes it difficult for the differential coupling between the signals of the first signal conductor 12 and the second signal conductor 13 to be weakened at the positions of the second portion 122 and the fifth portion 132 where the widths of the signal conductors are narrow. Furthermore, if the first edge 126 is linear from the second portion 122 to the third portion 123, the distance between the first signal conductor 12 and the third ground conductor 16 is likely to be constant in this portion. Similarly, if the second edge 136 is linear from the fifth portion 132 to the sixth portion 133, the distance between the second signal conductor 13 and the third ground conductor 16 is likely to be constant in this portion. This makes it easier to adjust the impedance of the first signal conductor 12 and the second signal conductor 13, and to reduce reflection loss and insertion loss.

[0023] 2 and 3, the end of the first notch 127 and the end of the second notch 137 may be tapered or rounded, thereby reducing sudden changes in impedance.

[0024] 3 and 4 , the first signal conductor 12 may have a third cutout portion 128 on the side where the second signal conductor 13 is located. The second portion 122 may have a width narrower than the third portion 123 due to the third cutout portion 128. Alternatively, the first signal conductor 12 may have both the first cutout portion 127 and the third cutout portion 128, and the width of the second portion 122 may be narrower than the third portion 123 due to both the first cutout portion 127 and the third cutout portion 128.

[0025] 3 and 4 , the second signal conductor 13 may have a fourth notch portion 138 on the side where the first signal conductor 12 is located. The fifth portion 132 may have a width narrower than the sixth portion 133 due to the fourth notch portion 138. Alternatively, the second signal conductor 13 may have both the second notch portion 137 and the fourth notch portion 138, and the width of the fifth portion 132 may be narrower than the sixth portion 133 due to both the second notch portion 137 and the fourth notch portion 138.

[0026] 3 and 4, the end of the third notch 128 and the end of the fourth notch 138 may be tapered or rounded, which makes it less likely that a sudden change in impedance will occur and helps reduce deterioration of the reflection characteristics.

[0027] The length of the second portion 122 and the length of the fifth portion 132 may be the same as shown in Figures 2 and 4, or may be different as shown in Figure 3. For example, when the first signal conductor 12 and the second signal conductor 13 are curved, the length of the second portion 122 and the length of the fifth portion 132 may be different from each other in order to adjust the electrical length and align the phases of the signals transmitted through each signal conductor. By aligning the phases of the signals transmitted through each signal conductor, noise resistance and reflection characteristics can be improved.

[0028] The length of the first portion 121 and the length of the fourth portion 131 may be the same as or different from each other. The length of the third portion 123 and the length of the sixth portion 133 may be the same as or different from each other. The "length" of each portion of the signal conductor is the dimension of the signal conductor in the direction in which the signal conductor extends.

[0029] 2 to 4, the first signal conductor 12 may have a first transition portion 124 whose width varies between the first portion 121 and the second portion 122. Similarly, the second signal conductor 13 may have a second transition portion 134 whose width varies between the fourth portion 131 and the fifth portion 132. The lengths of the first transition portion 124 and the second transition portion 134 may be the same or different from each other.

[0030] 2 to 4, the first signal conductor 12 may have a third transition portion 125 of varying width between the second portion 122 and the third portion 123. Similarly, the second signal conductor 13 may have a fourth transition portion 135 of varying width between the fifth portion 132 and the sixth portion 133. The lengths of the third transition portion 125 and the fourth transition portion 135 may be the same or different from each other.

[0031] 2 to 4, in the first transition portion 124, the first edge 126 may be tapered or rounded. Similarly, in the second transition portion 134, the second edge 136 may be tapered or rounded. This makes it less likely that a sudden change in impedance will occur, and makes it easier to reduce deterioration of the reflection characteristics.

[0032] 2 to 4 , the first end 161, which is the end of the third ground conductor 16 on the first side surface 111 side, may be curved, and more specifically, may be semicircular. This reduces the change in the distance between the first transition portion 124 and the third ground conductor 16 when the first edge 126 of the first transition portion 124 is tapered or rounded. Furthermore, this reduces the change in the distance between the second transition portion 134 and the third ground conductor 16 when the second edge 136 of the second transition portion 134 is tapered or rounded. This reduces the occurrence of resonance and electric field disturbance.

[0033] 2 and 4 , in a side view seen along the first direction (X direction), the first end 161 may overlap the first transition portion 124 and the second transition portion 134. This reduces the possibility that the inductance component will be too strong in the second portion 122 and the fifth portion 132, where the width of each signal conductor is narrow, and thus the reflection characteristics will deteriorate.

[0034] 3, in a side view seen along the first direction (X direction), the first end 161 may overlap with at least one of the second portion 122 and the fifth portion 132. This reduces the possibility that the inductance component will be too strong in at least one of the second portion 122 and the fifth portion 132, which have narrow widths of the signal conductors, thereby degrading the reflection characteristics.

[0035] As shown in FIGS. 2 and 3 , the first gap 17, which is the gap between the first signal conductor 12 and the first ground conductor 14, may have, in order from the first side surface 111 side, a seventh portion 171, an eighth portion 172, and a ninth portion 173. The width of the seventh portion 171 is constant. The width of the eighth portion 172 is constant and wider than the seventh portion 171. The width of the ninth portion 173 is constant and narrower than the eighth portion 172. The second portion 122 may be adjacent to the eighth portion 172. The second gap 18, which is the gap between the second signal conductor 13 and the second ground conductor 15, may have, in order from the first side surface 111 side, a tenth portion 181, an eleventh portion 182, and a twelfth portion 183. The width of the tenth portion 181 is constant. The width of the eleventh portion 182 is constant and wider than the tenth portion 181. The width of the twelfth portion 183 is constant and narrower than that of the eleventh portion 182. The fifth portion 132 may be adjacent to the eleventh portion 182. This configuration increases the spacing between the signal conductor and the ground conductor adjacent to the second portion 122 and the fifth portion 132, where it is desired to increase the inductance component. This reduces the possibility that the capacitance component will increase in the second portion 122 and the fifth portion 132, and thus reduces the possibility of a decrease in impedance.

[0036] The width of the seventh portion 171 and the width of the ninth portion 173 may be the same as or different from each other. The width of the tenth portion 181 and the width of the twelfth portion 183 may be the same as or different from each other.

[0037] The width of the seventh portion 171 and the width of the tenth portion 181 are, for example, 0.03 to 0.2 mm and may be the same or different. The width of the eighth portion 172 and the width of the eleventh portion 182 are, for example, 0.04 to 0.3 mm and may be the same or different. The width of the ninth portion 173 and the width of the twelfth portion 183 are, for example, 0.03 to 0.2 mm and may be the same or different.

[0038] The "width" of each portion of the first interval 17 is the dimension of the first interval 17 in a direction perpendicular to the extension direction of the first interval 17 in the XY plane. The "width" of each portion of the second interval 18 is the dimension of the second interval 18 in a direction perpendicular to the extension direction of the second interval 18 in the XY plane.

[0039] 3, the first ground conductor 14 may have a first protrusion 141 at a position facing the first portion 121. Similarly, the second ground conductor 15 may have a second protrusion 151 at a position facing the fourth portion 131. This makes it easier to increase the capacitance components of the first portion 121 and the fourth portion 131 by partially narrowing the gap between the signal conductor and the ground conductor. Furthermore, by partially widening the first ground conductor 14 and the second ground conductor 15, it becomes easier to ensure connection areas for external terminals in the first ground conductor 14 and the second ground conductor 15.

[0040] As shown in FIGS. 2 to 4 , the first signal conductor 12 and the second signal conductor 13 may or may not be in contact with the first side surface 111. In other words, the first signal conductor 12 and the second signal conductor 13 may be spaced from the first side surface 111, or may be spaced from the first side surface 111. When the first signal conductor 12 and the second signal conductor 13 are in contact with the first side surface 111, the connecting member 33 can be shortened when the first signal conductor 12 and the second signal conductor 13 are connected to an electronic component 32, a relay board, or the like. This reduces degradation of high-frequency characteristics. The connecting member 33 may be, for example, a bonding wire, a ribbon wire, a lead terminal, or the like. On the other hand, when the first signal conductor 12 and the second signal conductor 13 are not in contact with the first side surface 111, pattern sagging on the first side surface 111 is less likely to occur during manufacturing. This reduces the possibility of pattern sagging remaining even when the first side surface 111 is not polished.

[0041] 2 to 4, the first ground conductor 14 and the second ground conductor 15 may be in contact with the first side surface 111, or may not be in contact with the first side surface 111. In other words, the first ground conductor 14 and the second ground conductor 15 may not be spaced from the first side surface 111, or may be spaced from the first side surface 111.

[0042] The wiring board 10 may further include a first inner-layer ground conductor 19 located within the insulating base 11. This stabilizes the ground potential. The first inner-layer ground conductor 19 is located below (on the negative side in the Z direction) the first signal conductor 12, the second signal conductor 13, and the like. No other conductors may be located between the first inner-layer ground conductor 19 and the first signal conductor 12 or between the first inner-layer ground conductor 19 and the second signal conductor 13. In FIGS. 5 and 6 , the first signal conductor 12 and the second signal conductor 13, which are located above (on the positive side in the Z direction) the first inner-layer ground conductor 19, are indicated by dashed lines. The first inner-layer ground conductor 19 may have multiple ground via conductors and may be electrically connected to the first ground conductor 14, the second ground conductor 15, and the third ground conductor 16 through the ground via conductors.

[0043] As shown in FIG. 5 , the first inner-layer ground conductor 19 may have multiple openings 191. In a plan view, the multiple openings 191 may be positioned side by side and overlap the first signal conductor 12 and the second signal conductor 13. This stabilizes the ground potential while reducing impedance reduction. The openings 191 may have a circular, semicircular, elliptical, polygonal, or other shape. The multiple openings 191 may have the same or different shapes. Note that the openings 191 refer to areas where no ground conductor is located, and do not necessarily represent holes in the inner layers of the wiring board 10. Note that the first inner-layer ground conductor 19 may have holes to form hollow portions. This reduces the dielectric constant of the first inner-layer ground conductor 19 and reduces the possibility of impedance reduction.

[0044] The wiring board 10 may further include another inner-layer ground conductor below (on the negative side in the Z direction) the first inner-layer ground conductor 19. The inner-layer ground conductor below the first inner-layer ground conductor 19 may also have a plurality of openings that overlap and are aligned with the first signal conductor 12 and the second signal conductor 13 in plan view, similar to the first inner-layer ground conductor 19.

[0045] 6 , the first inner-layer ground conductor 19 may be spaced apart from the first portion 121 and the fourth portion 131 in plan view. If no other conductors are located between the first inner-layer ground conductor 19 and the first signal conductor 12 and between the first inner-layer ground conductor 19 and the second signal conductor 13, and if the first inner-layer ground conductor 19 is spaced apart from the first portion 121 and the fourth portion 131 in plan view, it is possible to reduce the possibility of resonance occurring or the possibility of the capacitance components of the first portion 121 and the fourth portion 131 becoming too large. In this case, another conductor may be located below the first inner-layer ground conductor 19 (on the negative side in the Z direction) in a position that overlaps with the first portion 121 and the fourth portion 131 in plan view.

[0046] 7 and 8 are graphs showing simulation results illustrating the effects of the wiring board 10 of the present disclosure. In this simulation, the embodiment of the present disclosure shown in FIG. 2 is designated "Embodiment A," and the embodiment of the present disclosure shown in FIG. 4 is designated "Embodiment B." Furthermore, as a comparative example, the embodiment shown in FIG. 9 is designated "Conventional Embodiment." The simulation results for Embodiment A and the conventional embodiment show that the wiring board 10 of the present disclosure has reduced reflection loss and insertion loss in the high frequency range of 90 GHz or higher compared to the conventional wiring board 10. Furthermore, the simulation results for Embodiments A and B show that the reflection loss and insertion loss are further reduced in the range of 90 to 160 GHz because the first edge 126 is linear from the second portion 122 to the third portion 123 and the second edge 136 is linear from the fifth portion 132 to the sixth portion 133.

[0047] 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 glass ceramics. 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 be used as a flexible printed circuit board (FPC), a printed circuit board (PCB), or the like.

[0048] The material of each conductor such as the first signal conductor 12 and the second signal conductor 13 is, for example, a metal such as tungsten, molybdenum, manganese, copper, gold, or silver, or an alloy of these.

[0049] When the insulating base 11 is made of an aluminum oxide sintered body and the conductors, such as the first signal conductor 12 and the second signal conductor 13, are made of tungsten metallized layers, the wiring substrate 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. Furthermore, 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 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 that order, on the surfaces of the first signal conductor 12, the second signal conductor 13, the first ground conductor 14, the second ground conductor 15, and the third ground conductor 16. This protects the surfaces and improves their bondability with brazing filler metals, solder, etc.

[0050] [Package for storing electronic components] As shown in FIG. 10 , 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.

[0051] The substrate 21 is, for example, a rectangular plate-like member. The frame 22 is a frame-like member provided in a position surrounding the mounting area for the electronic component 32 in a plan view. As shown in Fig. 10 , the frame 22 may have a light-transmitting portion 221 for transmitting and receiving light between the inside and outside of the electronic component housing package 20.

[0052] 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.

[0053] The frame body 22 may be integrally molded with the insulating base 11 of the wiring board 10, or may be a separate body from the insulating base 11 of the wiring board 10. If the frame body 22 and the insulating base 11 are made of the same material, they can be easily molded integrally.

[0054] 10 , the electronic component storage package 20 may include a seal ring 23 located on the upper surface of the frame 22. The seal ring 23 can function 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 23 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 with a brazing material or the like.

[0055] [Electronic Module] As shown in FIG. 11 , 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 first signal conductor 12 and the second signal conductor 13, and a lid 34 located on a frame 22.

[0056] 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 first signal conductor 12 and the second signal conductor 13 by a connection member 33 such as a bonding wire. Alternatively, the electronic component 32 may be electrically connected to the first signal conductor 12 and the second signal conductor 13 by flip-chip mounting.

[0057] The electronic component 32 is, for example, an electronic component that inputs or outputs a high-frequency signal related to optical communication (for example, a signal with a frequency band of about 10 GHz or higher). Specific examples of the electronic component 32 include a light-emitting element and a light-receiving element.

[0058] The lid 34 is, for example, a plate-shaped member 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 23, or may be made by processing and forming the same material as the substrate 21 and the frame 22 into a plate shape.

[0059] Hereinafter, further examples of embodiments of the wiring board, electronic component storage package, and electronic module according to the present disclosure will be described.

[0060] (1) One embodiment of a wiring board according to the present disclosure comprises: an insulating base having a first side surface; a first signal conductor and a second signal conductor extending from the first side surface toward the inside of the insulating base; a first ground conductor located on the opposite side of the second signal conductor with the first signal conductor in between; a second ground conductor located on the opposite side of the second signal conductor with the second signal conductor in between; and a third ground conductor located between the first signal conductor and the second signal conductor, wherein the first ground conductor, the first signal conductor, the third ground conductor, the second signal conductor, and the second ground conductor are located on the insulating base at intervals from each other, and the first signal conductor has, in order from the first side surface, a first portion having a constant width, a second portion having a constant width and narrower than the first portion, and a third portion having a constant width and narrower than the first portion and wider than the second portion, The second signal conductor has, in order from the first side surface side, a fourth portion having a constant width, a fifth portion having a constant width and narrower than the fourth portion, and a sixth portion having a constant width and narrower than the fourth portion and wider than the fifth portion; a first region in which the first ground conductor, the first signal conductor, the second signal conductor, and the second ground conductor are aligned in a first direction along the first side surface and are located closer to the first side surface than the third ground conductor; and a second region in which the first ground conductor, the first signal conductor, the third ground conductor, the second signal conductor, and the second ground conductor are aligned in the first direction, more inward of the insulating base than the first region.

[0061] (2) One embodiment of the wiring board according to the present disclosure is the wiring board of (1) above, wherein the first signal conductor has a first notch portion on the side where the first ground conductor is located, the second portion has a width narrower than the third portion due to the first notch portion, the second signal conductor has a second notch portion on the side where the second ground conductor is located, and the fifth portion has a width narrower than the sixth portion due to the second notch portion.

[0062] (3) One embodiment of the wiring board according to the present disclosure is the wiring board of (2) above, wherein a first edge of the first signal conductor on the side where the second signal conductor is located is linear from the second portion to the third portion, and a second edge of the second signal conductor on the side where the first signal conductor is located is linear from the fifth portion to the sixth portion.

[0063] (4) One embodiment of the wiring board according to the present disclosure is the wiring board of (2) or (3) above, wherein the end of the first cutout portion and the end of the second cutout portion are tapered or rounded.

[0064] (5) One embodiment of the wiring board according to the present disclosure is the wiring board of any of (1) to (4) above, wherein the first signal conductor has a first transition portion of varying width between the first portion and the second portion, the second signal conductor has a second transition portion of varying width between the fourth portion and the fifth portion, and in a side view along the first direction, a first end of the third ground conductor on the first side surface overlaps with the first transition portion and the second transition portion.

[0065] (6) One embodiment of the wiring board according to the present disclosure is the wiring board of (5) above, wherein, in the first transition portion, a first edge of the first signal conductor on the side where the second signal conductor is located is tapered or rounded, and in the second transition portion, a second edge of the second signal conductor on the side where the first signal conductor is located is tapered or rounded, and the first end is curved.

[0066] (7) One embodiment of a wiring board according to the present disclosure is the wiring board of any of (1) to (6) above, wherein the first gap between the first signal conductor and the first ground conductor has, in order from the first side surface side, a seventh portion having a constant width, an eighth portion having a constant width and wider than the seventh portion, and a ninth portion having a constant width and narrower than the eighth portion, the second portion being adjacent to the eighth portion, the second gap between the second signal conductor and the second ground conductor has, in order from the first side surface side, a tenth portion having a constant width, an eleventh portion having a constant width and wider than the tenth portion, and a twelfth portion having a constant width and narrower than the eleventh portion, the fifth portion being adjacent to the eleventh portion.

[0067] (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 grounding conductor has a first protrusion at a position facing the first portion, and the second grounding conductor has a second protrusion at a position facing the fourth portion.

[0068] (9) One embodiment of the wiring board according to the present disclosure is the wiring board of any of (1) to (8) above, wherein, in a side view along the first direction, a first end of the third ground conductor on the first side surface overlaps with at least one of the second portion and the fifth portion.

[0069] (10) One embodiment of the wiring board according to the present disclosure is the wiring board according to any one of (1) to (9) above, wherein the length of the second portion and the length of the fifth portion are different from each other.

[0070] (11) One embodiment of the wiring board according to the present disclosure is the wiring board according to any one of (1) to (10) above, wherein the first signal conductor and the second signal conductor are in contact with the first side surface.

[0071] (12) One embodiment of a wiring board according to the present disclosure is the wiring board of any one of (1) to (11). The wiring board further includes a first inner-layer ground conductor located within the insulating base, wherein no other conductors are located between the first inner-layer ground conductor and the first signal conductor and between the first inner-layer ground conductor and the second signal conductor, and the first inner-layer ground conductor has a plurality of openings, and the openings are positioned side by side and overlap with the first signal conductor and the second signal conductor in a plan view.

[0072] (13) One embodiment of the wiring board according to the present disclosure is the wiring board of any of (1) to (12) above, further comprising a first inner-layer ground conductor located within the insulating base, no other conductors being located between the first inner-layer ground conductor and the first signal conductor and between the first inner-layer ground conductor and the second signal conductor, and the first inner-layer ground conductor being spaced apart from the first portion and the fourth portion in a planar view.

[0073] (14) One embodiment of a package for storing electronic components 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.

[0074] (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 first signal conductor and the second signal conductor; and a lid located on the frame.

[0075] 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.

[0076] 10 Wiring board 11 Insulating base 111 First side surface 12 First signal conductor 121 First portion 122 Second portion 123 Third portion 124 First transition portion 125 Third transition portion 126 First edge 127 First notch portion 128 Third notch portion 13 Second signal conductor 131 Fourth portion 132 Fifth portion 133 Sixth portion 134 Second transition portion 135 Fourth transition portion 136 Second edge 137 Second notch portion 138 Fourth notch portion 14 First ground conductor 141 First protrusion portion 15 Second ground conductor 151 Second protrusion portion 16 Third ground conductor 161 First end 17 First gap 171 Seventh portion 172 Eighth portion 173 Ninth portion 18 Second gap 181 Part 10 182 Part 11 183 Part 12 19 First inner-layer ground conductor 191 Opening 20 Electronic component storage package 21 Substrate 22 Frame 221 Light-transmitting portion 23 Seal ring 30 Electronic module 31 Mounting member 32 Electronic component 33 Connection member 34 Lid A1 First region A2 Second region

Claims

1. An insulating base having a first side surface; a first signal conductor and a second signal conductor extending from the first side surface toward the inside of the insulating base; a first ground conductor located on the opposite side of the second signal conductor with the first signal conductor in between; a second ground conductor located on the opposite side of the second signal conductor with the second signal conductor in between; and a third ground conductor located between the first and second signal conductors, wherein the first ground conductor, the first signal conductor, the third ground conductor, the second signal conductor, and the second ground conductor are located on the insulating base at intervals from each other, and the first signal conductor has, in order from the first side surface, a first portion having a constant width, a second portion having a constant width and narrower than the first portion, and a third portion having a constant width and narrower than the first portion and wider than the second portion, the second signal conductor has, in order from the first side surface side, a fourth portion having a constant width, a fifth portion having a constant width and narrower than the fourth portion, and a sixth portion having a constant width and narrower than the fourth portion and wider than the fifth portion; a first region in which the first ground conductor, the first signal conductor, the second signal conductor, and the second ground conductor are aligned in a first direction along the first side surface and are positioned closer to the first side surface than the third ground conductor; and a second region inward of the insulating base than the first region, in which the first ground conductor, the first signal conductor, the third ground conductor, the second signal conductor, and the second ground conductor are aligned in the first direction.

2. The wiring board of claim 1, wherein the first signal conductor has a first cutout portion on the side where the first ground conductor is located, the second portion has a width narrower than the third portion due to the first cutout portion, the second signal conductor has a second cutout portion on the side where the second ground conductor is located, and the fifth portion has a width narrower than the sixth portion due to the second cutout portion.

3. The wiring board according to claim 2, wherein a first edge of the first signal conductor on the side where the second signal conductor is located is linear from the second portion to the third portion, and a second edge of the second signal conductor on the side where the first signal conductor is located is linear from the fifth portion to the sixth portion.

4. The wiring board according to claim 2 or 3, wherein the end of the first cutout portion and the end of the second cutout portion are tapered or rounded.

5. A wiring board as claimed in any one of claims 1 to 4, wherein the first signal conductor has a first transition portion of varying width between the first and second portions, the second signal conductor has a second transition portion of varying width between the fourth and fifth portions, and in a side view seen along the first direction, a first end of the third ground conductor on the first side surface overlaps with the first transition portion and the second transition portion.

6. The wiring board according to claim 5, wherein, in the first transition portion, a first edge of the first signal conductor on the side where the second signal conductor is located is tapered or rounded; and, in the second transition portion, a second edge of the second signal conductor on the side where the first signal conductor is located is tapered or rounded; and the first end is curved.

7. A wiring board as claimed in any one of claims 1 to 6, wherein a first gap between the first signal conductor and the first ground conductor has, in order from the first side surface side, a seventh portion having a constant width, an eighth portion having a constant width and wider than the seventh portion, and a ninth portion having a constant width and narrower than the eighth portion, the second portion being adjacent to the eighth portion, and a second gap between the second signal conductor and the second ground conductor has, in order from the first side surface side, a tenth portion having a constant width, an eleventh portion having a constant width and wider than the tenth portion, and a twelfth portion having a constant width and narrower than the eleventh portion, the fifth portion being adjacent to the eleventh portion.

8. A wiring board according to any one of claims 1 to 7, wherein the first ground conductor has a first protrusion at a position facing the first portion, and the second ground conductor has a second protrusion at a position facing the fourth portion.

9. A wiring board as described in any one of claims 1 to 8, wherein, in a side view along the first direction, a first end of the third ground conductor on the first side surface overlaps with at least one of the second portion and the fifth portion.

10. The wiring board according to any one of claims 1 to 9, wherein the length of the second portion and the length of the fifth portion are different from each other.

11. The wiring board according to any one of claims 1 to 10, wherein the first signal conductor and the second signal conductor are in contact with the first side surface.

12. The wiring board according to any one of claims 1 to 11, further comprising a first inner-layer ground conductor located within said insulating base, wherein no other conductors are located between said first inner-layer ground conductor and said first signal conductor and between said first inner-layer ground conductor and said second signal conductor, and said first inner-layer ground conductor has a plurality of openings, and in plan view, said plurality of openings are located side by side and overlap with said first signal conductor and said second signal conductor.

13. The wiring board according to any one of claims 1 to 12, further comprising a first inner-layer ground conductor located within said insulating base, wherein no other conductors are located between said first inner-layer ground conductor and said first signal conductor and between said first inner-layer ground conductor and said second signal conductor, and wherein said first inner-layer ground conductor is spaced apart from said first portion and said fourth portion in plan view.

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 first signal conductor and the second signal conductor; and a lid located on the frame.

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