Wiring board, electronic component housing package, and electronic module

Abstract

This wiring board comprises a first insulating substrate, a first signal conductor, a second signal conductor, and a first grounding conductor. The first insulating substrate has a first upper surface and a first side surface connected to the first upper surface. The first signal conductor and the second signal conductor are positioned on the first upper surface and arranged side by side in a first direction along the first side surface in a plan view. The first grounding conductor is positioned between the first signal conductor and the second signal conductor on the first upper surface and is in contact with the first side surface. The first insulating substrate has a first cutout portion and a second cutout portion obtained by cutting out the first insulating substrate from the first upper surface on which the first grounding conductor is positioned to the first side surface. The first grounding conductor covers a first wall surface of the first cutout portion and a second wall surface of the second cutout portion.

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 wiring board having castellations connected to the ends of a ground conductor is known.

[0003] JP 2009-158511 A

[0004] The wiring board according to the present disclosure includes a first insulating base, a first signal conductor, a second signal conductor, and a first ground conductor. The first insulating base has a first upper surface and a first side surface connected to the first upper surface. The first signal conductor and the second signal conductor are positioned side by side on the first upper surface in a first direction along the first side surface in a plan view. The first ground conductor is positioned between the first signal conductor and the second signal conductor on the first upper surface and is in contact with the first side surface. The first insulating base has a first notch portion and a second notch portion cut out from the first upper surface on which the first ground conductor is located to the first side surface. The first ground conductor covers a first wall surface of the first notch portion and a second wall surface of the second notch portion.

[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] 2 is a perspective view of a wiring board according to an embodiment of the present disclosure; FIG. 3 is a plan view of the wiring board shown in FIG. 1; FIG. 4 is an enlarged view of a main part A in FIG. 2; FIG. 5 is an enlarged view of a first cutout portion; FIG. 6 is an enlarged view of a second cutout portion; FIG. 7 is an enlarged view of a third cutout portion; and FIG. 8 is an enlarged view of a fifth cutout portion. FIG. 9 is a perspective view of an electronic component storage package; and FIG. 10 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, with the increasing frequency of signals in wiring boards, there has been a demand for stabilizing the ground potential to reduce the effects of noise. In addition, there has been a demand for improving the bonding strength between the wiring board and the external terminals bonded to the wiring board in order to improve connection reliability.

[0012] The wiring board, electronic component storage package, and electronic module of the present disclosure can stabilize the ground potential and improve the bonding strength with the external terminals.

[0013] 1 to 5 , the wiring substrate 10 includes a first insulating base 20, a first signal conductor 51, a second signal conductor 52, and a first ground conductor 41. The first insulating base 20 has a first upper surface 201 and a first side surface 202 connected to the first upper surface 201. The first signal conductor 51 and the second signal conductor 52 are positioned side by side on the first upper surface 201 in a first direction (X direction) along the first side surface 202 in a plan view. The first ground conductor 41 is positioned between the first signal conductor 51 and the second signal conductor 52 on the first upper surface 201 and is in contact with the first side surface 202. The first insulating base 20 has a first notch 21 and a second notch 22 cut out from the first upper surface 201, where the first ground conductor 41 is located, to the first side surface 202. As shown in FIGS. 4 and 5 , the first ground conductor 41 covers the first wall surface 211 of the first cutout portion 21 and the second wall surface 221 of the second cutout portion 22 .

[0014] In high-frequency designs, impedance fluctuations tend to increase at the joint between the conductor located on the first top surface 201 and the external terminal. Here, if the ground conductor located on the first top surface 201 is connected to the inner-layer ground conductor at the tip of the joint, the ground potential is stabilized and impedance fluctuations are likely to be reduced. Therefore, if a notch is present and the ground conductor located on the first top surface 201 is connected to the inner-layer ground conductor through the wall of the notch, impedance fluctuations are likely to be reduced. Furthermore, a fillet of bonding material may be formed in the notch when bonding to the external terminal. Therefore, the presence of the notch tends to improve the bonding strength with the external terminal. The wiring board 10 of the present disclosure includes at least two such notches, the first notch 21 and the second notch 22, thereby further stabilizing the ground potential and improving the bonding strength with the external terminal. Furthermore, because the area between the first notch 21 and the second notch 22 can serve as a bonding surface with the external terminal, the bonding strength with the external terminal can be improved compared to when a single large notch is formed, such that the first notch 21 and the second notch 22 are connected. When a single large notch is formed, such that the first notch 21 and the second notch 22 are connected, the bonding material placed on the ground conductor tends to flow along the wall surface of the notch to the bottom of the notch, making it difficult to form a fillet. In contrast, when multiple notches of appropriate width are formed, the bonding material is able to remain appropriately between the ground conductor and the notch, making it easier to form a fillet, thereby improving the bonding strength between the ground conductor and the external terminal. Furthermore, if the first notch 21 and the second notch 22 are positioned at an appropriate distance from each other, the positions where fillets are formed can be dispersed, making it easier to improve the bonding strength.

[0015] Examples of external terminals that can be joined to the wiring board 10 include terminals of flexible printed circuits (FPCs), terminals of flip-chip mounted electronic components, lead terminals, bonding wires, and the like.

[0016] The shape of the first notch portion 21 and the second notch portion 22 in a plan view is not particularly limited, and may be semicircular, rectangular, rectangular with rounded corners, etc. The first notch portion 21 and the second notch portion 22 may be cut out from the first upper surface 201 to the lower surface of the first insulating base 20 (the surface opposite to the first upper surface 201), and may not have a first bottom surface 212 and a second bottom surface 222, respectively, which will be described later.

[0017] The first insulating base 20 may have other notches cut out from the first upper surface 201, where the first ground conductor 41 is located, to the first side surface 202, in addition to the first notch 21 and the second notch 22. That is, the number of notches cut out from the first upper surface 201, where the first ground conductor 41 is located, to the first side surface 202 may be three or more.

[0018] 4 and 5, the first ground conductor 41 may cover the first bottom surface 212 of the first cutout portion 21 and the second bottom surface 222 of the second cutout portion 22. This further stabilizes the ground potential.

[0019] 3 , on a line overlapping the first side surface 202 in a plan view, a distance D1 between the first end of the first ground conductor 41 on the first signal conductor 51 side and the first notch 21 may be smaller than a distance D2 between the center of the first ground conductor 41 and the first notch 21. Furthermore, on a line overlapping the first side surface 202 in a plan view, a distance D3 between the second end of the first ground conductor 41 on the second signal conductor 52 side and the second notch 22 may be smaller than a distance D4 between the center of the first ground conductor 41 and the second notch 22. This increases the distance between the first notch 21 and the second notch 22. This reduces the possibility of cracking in the first insulating base 20 and improves the strength of the wiring board 10. Furthermore, by arranging the first notch 21 and the second notch 22 at an appropriate distance from each other, fillets can be formed at an appropriate distance when bonding to an external terminal, which makes it easier to improve the bonding strength with the external terminal. At this time, other notches may be present between the first notch 21 and the second notch 22, but the absence of other notches further reduces the possibility of cracks occurring in the first insulating base 20 and makes it easier to improve the bonding strength with the external terminal.

[0020] As shown in FIG. 3 , the first ground conductor 41 may have a first portion 411 and a second portion 412. The first portion 411 is in contact with the first side surface 202 and has a width that narrows with increasing distance from the first side surface 202. The second portion 412 is connected to the first portion 411 and has a constant width. In this case, at least a portion of the first notch portion 21 and at least a portion of the second notch portion 22 may protrude in the first direction (X direction) beyond the second portion 412. This increases the distance between the first notch portion 21 and the second notch portion 22. This reduces the possibility of cracks occurring in the first insulating base 20 and improves the strength of the wiring substrate 10. Furthermore, because the region between the first notch portion 21 and the second notch portion 22 can be a bonding region with an external terminal, increasing this region increases the bonding strength with the external terminal. The "width" of each portion of the first ground conductor 41 is the dimension of the first ground conductor 41 in a direction perpendicular to the extending direction of the first ground conductor 41 on the first upper surface 201. In FIG. 3 , the dimension in the X direction is the width.

[0021] As shown in Figures 1, 2 and 6, the first insulating base 20 may have a second side surface 203 connected to the first upper surface 201 and the first side surface 202. The second side surface 203 may be located on either the positive or negative side in the X direction. The corner between the first side surface 202 and the second side surface 203 of the first insulating base 20 may be a C-surface. This reduces stress applied to the first insulating base 20. The "C-surface" is a surface formed by rounding off a corner formed by two perpendicular surfaces.

[0022] 1, 2, and 6, the wiring substrate 10 may further include a second ground conductor 42. The second ground conductor 42 may be located on the first upper surface 201 and may be in contact with the first side surface 202 and the second side surface 203. This further stabilizes the ground potential.

[0023] As shown in Figures 1, 2, and 6, the first insulating base 20 may have a third notch 23 cut out from the first top surface 201 to the first side surface 202 and the second side surface 203. If the corner between the first side surface 202 and the second side surface 203 is a chamfered surface, the chamfered surface is also considered to be the second side surface 203. By cutting out the first insulating base 20 from the first top surface 201 to the first side surface 202 and the second side surface 203 with the third notch 23, stress applied to this portion is alleviated. Furthermore, if the third notch 23 is provided at a small distance from the second side surface 203, there is a possibility that cracks will occur in the first insulating base 20 at that distance. However, by cutting out the third notch 23 to the second side surface 203, this possibility is reduced. Furthermore, compared to when the third notch portion 23 is provided with a large gap between it and the second side surface 203, the wiring board 10 can be more easily miniaturized by cutting the third notch portion 23 out to the second side surface 203.

[0024] 6, the second ground conductor 42 may cover the third wall surface 231 of the third cutout portion 23, and may also cover the third bottom surface 232 of the third cutout portion 23. This further stabilizes the ground potential.

[0025] The third cutout portion 23 may have a dimension in the first direction (X direction) larger than the first cutout portion 21 and the second cutout portion 22. This increases the stress relaxation effect of the third cutout portion 23.

[0026] 1, 2, and 7, the first insulating base 20 may have a third side surface 204 connected to the first upper surface 201 and the first side surface 202 on the opposite side to the second side surface 203. The corner between the first side surface 202 and the third side surface 204 of the first insulating base 20 may be a C-plane. This relieves stress acting on the first insulating base 20.

[0027] 1, 2, and 7, the wiring substrate 10 may further include a fifth ground conductor 45. The fifth ground conductor 45 may be located on the first upper surface 201 and may be in contact with the first side surface 202 and the third side surface 204. This further stabilizes the ground potential.

[0028] As shown in Figures 1, 2, and 7, the first insulating base 20 may have a fifth notch 25 cut out from the first top surface 201 to the first side surface 202 and the third side surface 204. If the corner between the first side surface 202 and the third side surface 204 is a chamfered surface, the chamfered surface is also considered to be the third side surface 204. By cutting out the first insulating base 20 from the first top surface 201 to the first side surface 202 and the third side surface 204 with the fifth notch 25, stress applied to this portion is alleviated. Furthermore, if the fifth notch 25 is provided at a small distance from the third side surface 204, there is a possibility that cracks will occur in the first insulating base 20 at that distance. However, by cutting out the fifth notch 25 to the third side surface 204, this possibility is eliminated. Furthermore, since the fifth notch portion 25 is cut out to the third side surface 204, compared to when the fifth notch portion 25 is provided with a large gap between it and the third side surface 204, the wiring board 10 can be more easily miniaturized.

[0029] 7, the fifth ground conductor 45 may cover a fifth wall surface 251 of the fifth cutout portion 25, and may also cover a fifth bottom surface 252 of the fifth cutout portion 25. This further stabilizes the ground potential.

[0030] The fifth cutout portion 25 may have a dimension in the first direction (X direction) larger than the first cutout portion 21 and the second cutout portion 22. This increases the stress relaxation effect of the fifth cutout portion 25.

[0031] 4 and 5 , at least one of the corners between the first wall surface 211 and the first side surface 202 and the corners between the second wall surface 221 and the first side surface 202 may be curved surfaces that are not covered by the first ground conductor 41 (shaded areas in the figures). This reduces the possibility of burrs or cracks occurring at the corners. If both the corners between the first wall surface 211 and the first side surface 202 and the corners between the second wall surface 221 and the first side surface 202 are curved surfaces that are not covered by the first ground conductor 41, the possibility of burrs or cracks occurring is further reduced.

[0032] 6, when the first insulating base 20 has the third notch 23, the corner between the third wall surface 231 and the first side surface 202 may be a C-surface that is not covered by the second ground conductor 42 (the shaded portion in the figure), thereby reducing the possibility of burrs or cracks occurring at the corner.

[0033] 7, when the first insulating base 20 has the fifth notch 25, the corner between the fifth wall surface 251 and the first side surface 202 may be a C-surface that is not covered by the fifth ground conductor 45 (the shaded area in the figure), thereby reducing the possibility of burrs or cracks occurring at the corner.

[0034] 1 to 3, the wiring substrate 10 may further include a second insulating base 30 located on the first upper surface 201 and spaced from the first side surface 202. The second insulating base 30 may be in contact with the first ground conductor 41, or may be located above the first ground conductor 41. The second insulating base 30 may be in contact with the first signal conductor 51 and the second signal conductor 52, or may be located above the first signal conductor 51 and the second signal conductor 52. The second insulating base 30 may be formed integrally with the first insulating base 20, or may be formed separately from the first insulating base 20. The second insulating base 30 may have castellations.

[0035] As shown in FIG. 3 , the first ground conductor 41 may have a third portion 413 whose width increases as it approaches the second insulating base 30. This further stabilizes the ground potential. Furthermore, the third portion 413 may be in contact with the second insulating base 30. This makes it easier to appropriately adjust the impedance of the first signal conductor 51 and the second signal conductor 52 below the second insulating base 30 when the first signal conductor 51 and the second signal conductor 52 extend below the second insulating base 30. Furthermore, when the second insulating base 30 has castellations, the first ground conductor 41 extending from the third portion 413 comes into contact with the castellations, thereby further stabilizing the ground potential.

[0036] When the first ground conductor 41 is in contact with the second insulating base 30, the width of the first ground conductor 41 at the position where it is in contact with the second insulating base 30 may be wider than the width of the first ground conductor 41 at the position where it is in contact with the first side surface 202. When the first ground conductor 41 has a third portion 413 and the third portion 413 is in contact with the second insulating base 30, the width of the third portion 413 at the position where it is in contact with the second insulating base 30 may be wider than the width of the first portion 411 at the position where it is in contact with the first side surface 202.

[0037] As shown in FIG. 3 , the first insulating base 20 may have a recess 24 opening to the first upper surface 201. The recess 24 may be one or more. The recess 24 may be located in contact with an edge of the first ground conductor 41 in the first direction (X direction) and may have a fourth wall surface and a fourth bottom surface. In this case, the first ground conductor 41 may cover at least a portion of the fourth wall surface and the fourth bottom surface. This increases the area of ​​the first ground conductor 41, further stabilizing the ground electrons. The first ground conductor 41 may cover only a portion of the fourth wall surface, or may cover the entire fourth wall surface. When the first ground conductor 41 covers the entire fourth wall surface, the ground electrons are further stabilized.

[0038] 1 to 3 , the wiring board 10 may include a third signal conductor 53, a third ground conductor 43, a fourth signal conductor 54, and a fourth ground conductor 44. The third signal conductor 53 may be located on the opposite side of the first ground conductor 41 with the first signal conductor 51 in between. The third ground conductor 43 may be located on the opposite side of the first signal conductor 51 with the third signal conductor 53 in between. The fourth signal conductor 54 may be located on the opposite side of the first ground conductor 41 with the second signal conductor 52 in between. The fourth ground conductor 44 may be located on the opposite side of the second signal conductor 52 with the fourth signal conductor 54 in between. This results in two GSSG structures: a GSSG structure formed by the third ground conductor 43, the third signal conductor 53, the first signal conductor 51, and the first ground conductor 41, and a GSSG structure formed by the first ground conductor 41, the second signal conductor 52, the fourth signal conductor 54, and the fourth ground conductor 44. The two GSSG structures share the first ground conductor 41, which makes it easier to miniaturize the wiring board 10 compared to a case where the two GSSG structures do not share the ground conductor. The GSSG structure is a differential line structure made up of multiple conductors arranged in the following order: ground conductor-signal conductor-signal conductor-ground conductor.

[0039] Furthermore, a sixth ground conductor may be located between the first signal conductor 51 and the third signal conductor 53, and a seventh ground conductor may be located between the second signal conductor 52 and the fourth signal conductor 54. This may result in a GSG structure constituted by the third ground conductor 43, the third signal conductor 53, the sixth ground conductor, the first signal conductor 51, and the first ground conductor 41, and a GSGSG structure constituted by the first ground conductor 41, the second signal conductor 52, the seventh ground conductor, the fourth signal conductor 54, and the fourth ground conductor 44. The GSGSG structure is a differential line structure constituted by a plurality of conductors arranged in the order ground conductor-signal conductor-ground conductor-signal conductor-ground conductor.

[0040] As shown in FIG. 3 , the wiring board 10 may have a first coating portion 61 and a second coating portion 62 located on the first upper surface 201 along the second insulating base 30. The first coating portion 61 may be located on the first signal conductor 51 and the third signal conductor 53. This reduces the possibility that, if plating is applied to the first signal conductor 51 and the third signal conductor 53, the plating will travel along the second insulating base 30 and cause a short circuit between the first signal conductor 51 and the third signal conductor 53. This also reduces the possibility that the first signal conductor 51 and the third signal conductor 53 will peel off from the first upper surface 201. Similarly, the second coating portion 62 may be located on the second signal conductor 52 and the fourth signal conductor 54. This reduces the possibility that, if plating is applied to the second signal conductor 52 and the fourth signal conductor 54, the plating will travel along the second insulating base 30 and cause a short circuit between the second signal conductor 52 and the fourth signal conductor 54. This also reduces the possibility that the second signal conductor 52 and the fourth signal conductor 54 will peel off from the first upper surface 201. The material of the first coating portion 61 and the second coating portion 62 is an insulator such as ceramic.

[0041] As shown in FIG. 3 , the first insulating base 20 may have a first slit 26 located between the first signal conductor 51 and the third signal conductor 53 and a second slit 27 located between the second signal conductor 52 and the fourth signal conductor 54. The first slit 26 and the second slit 27 may be filled with a dielectric such as air, resin, or glass, and have a lower dielectric constant than the first insulating base 20. This reduces the capacitance between the first signal conductor 51 and the third signal conductor 53 and between the second signal conductor 52 and the fourth signal conductor 54. This makes it easier to appropriately adjust the impedance of each signal conductor and reduce signal loss. The first slit 26 and the second slit 27 may be spaced from the second insulating base 30 as shown in FIG. 3 , or may extend to a position where they contact the second insulating base 30.

[0042] The first insulating base 20 may also have slits filled with a dielectric such as air, resin, or glass between the first signal conductor 51 and the first ground conductor 41, between the second signal conductor 52 and the first ground conductor 41, between the third signal conductor 53 and the third ground conductor 43, and between the fourth signal conductor 54 and the fourth ground conductor 44, etc.

[0043] The wiring board 10 may have an inner-layer ground conductor located in the inner layer of the first insulating base 20. This further stabilizes the ground potential. In this case, as shown in FIG. 3 , the wiring board 10 may have a plurality of ground via conductors 46 connecting a ground conductor, such as the first ground conductor 41 located on the first upper surface 201, to the inner-layer ground conductor. Furthermore, the first ground conductor 41 is connected to the inner-layer ground conductor via the first wall surface 211 and the second wall surface 221, thereby further stabilizing the ground potential.

[0044] The first signal conductor 51 and the first ground conductor 41 may have protrusions facing each other. Similarly, the second signal conductor 52 and the first ground conductor 41 may also have protrusions facing each other. The protrusions may exist as a remnant of a case in which the conductors, such as the first ground conductor 41, located on the first upper surface 201 are plated together by electrolytic plating and then the connection portions of the conductors are laser-cut.

[0045] The material of the first insulating base 20 and the second insulating base 30 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 first insulating base 20 and the second insulating base 30 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 first insulating base 20 and the second insulating base 30, the wiring board 10 can be used as a flexible printed circuit board (FPC), a printed circuit board (PCB), or the like.

[0046] The material of each conductor such as the first ground conductor 41, the first signal conductor 51, and the second signal conductor 52 is, for example, a metal such as tungsten, molybdenum, manganese, copper, gold, or silver, or an alloy thereof.

[0047] When the first insulating base 20 and the second insulating base 30 are made of an aluminum oxide sintered body and the conductors, such as the first ground conductor 41, the first signal conductor 51, and the second signal conductor 52, are made of tungsten metallized layers, the wiring substrate 10 can be fabricated, for example, as follows: First, the raw material powder for the first insulating base 20 and the second insulating base 30 is mixed with an organic solvent and an organic binder to form a slurry. The raw material powder for the first insulating base 20 and the second insulating base 30 is primarily composed of aluminum oxide powder and a sintering aid powder such as silicon oxide. 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. Tungsten powder is then mixed with an organic solvent and an organic binder to form a metal paste. The metal paste is then printed on a predetermined position on a 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. The ground via conductors 46 can be formed by forming through-holes at predetermined positions in the ceramic green sheets prior to printing the metal paste, filling the through-holes with the same metal paste as described above, and firing the laminate together with the ceramic green sheets. 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 ground conductor 41, first signal conductor 51, second signal conductor 52, and other conductors located on the first upper surface 201. This protects the surfaces and improves bonding with brazing filler metals, solder, and the like.

[0048] 8 , electronic component storage package 70 may include a substrate 71, a frame 72 located on substrate 71, and wiring board 10 bonded to frame 72. Wiring board 10 is provided such that first side surface 202 faces outward from electronic component storage package 70.

[0049] The substrate 71 is, for example, a rectangular plate-like member. The frame body 72 is a frame-like member provided in a position surrounding the mounting area for the electronic component 82 in a plan view. As shown in Fig. 8 , the frame body 72 may have a light-transmitting portion 721 for transmitting and receiving light between the inside and outside of the electronic component housing package 70.

[0050] The substrate 71 and the frame 72 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 71 and the frame 72 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 71 and the material of the frame 72 may be the same as or different from each other.

[0051] The frame body 72 may be integrally molded with the first insulating base 20 of the wiring substrate 10, or may be a separate body from the first insulating base 20. If the frame body 72 and the first insulating base 20 are made of the same material, they are easily molded integrally.

[0052] 8 , electronic component storage package 70 may include a seal ring 73 located on the upper surface of frame 72. Seal ring 73 can function as a sealant when hermetically sealing electronic component 82 with lid 84 after electronic component 82 is mounted in electronic component storage package 70. Seal ring 73 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.

[0053] [Electronic Module] As shown in FIG. 9 , an electronic module 80 may include an electronic component storage package 70, an electronic component 82 located on a substrate 71 and electrically connected to the first signal conductor 51 and the second signal conductor 52, and a lid 84 located on the frame 72.

[0054] The electronic component 82 may be located on a mount member 81 provided on the substrate 71. The electronic component 82 may be electrically connected to the first signal conductor 51 and the second signal conductor 52 by a connecting member such as a bonding wire 83. Alternatively, the electronic component 82 may be electrically connected to the first signal conductor 51 and the second signal conductor 52 by flip-chip mounting.

[0055] The electronic component 82 is an electronic component that inputs or outputs, for example, 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 82 include a light-emitting element and a light-receiving element.

[0056] The lid 84 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 80. The lid 84 may be made of the same metal material as the seal ring 73, or may be made by processing and forming the same material as the substrate 71 and the frame 72 into a plate shape.

[0057] Hereinafter, further examples of embodiments of the wiring board, electronic component storage package, and electronic module according to the present disclosure will be described.

[0058] (1) One embodiment of a wiring board according to the present disclosure comprises: a first insulating base having a first top surface and a first side surface connected to the first top surface; a first signal conductor and a second signal conductor positioned side by side on the first top surface in a first direction along the first side surface in a plan view; and a first ground conductor positioned on the first top surface between the first signal conductor and the second signal conductor and in contact with the first side surface, wherein the first insulating base has a first notch portion and a second notch portion cut out from the first top surface on which the first ground conductor is located to the first side surface, and the first ground conductor covers a first wall surface of the first notch portion and a second wall surface of the second notch portion.

[0059] (2) One embodiment of the wiring board according to the present disclosure is the wiring board of (1) above, wherein the first grounding conductor covers a first bottom surface of the first cutout portion and a second bottom surface of the second cutout portion.

[0060] (3) One embodiment of the wiring board according to the present disclosure is the wiring board of (1) or (2) above, wherein, on a line overlapping with the first side surface in a planar view, the distance between a first end of the first ground conductor on the side of the first signal conductor and the first notch is smaller than the distance between the center of the first ground conductor and the first notch, and on a line overlapping with the first side surface in a planar view, the distance between a second end of the first ground conductor on the side of the second signal conductor and the second notch is smaller than the distance between the center of the first ground conductor and the second notch.

[0061] (4) One embodiment of the wiring board according to the present disclosure is the wiring board of any of (1) to (3) above, wherein the first grounding conductor has a first portion that is in contact with the first side surface and whose width narrows with increasing distance from the first side surface, and a second portion that is connected to the first portion and has a constant width, and at least a portion of the first cutout portion and at least a portion of the second cutout portion protrude in the first direction beyond the second portion.

[0062] (5) One embodiment of the wiring board according to the present disclosure is the wiring board of any one of (1) to (4) above, wherein the first insulating base has a second side surface connected to the first upper surface and the first side surface, and further includes a second ground conductor located on the first upper surface and in contact with the first side surface and the second side surface.

[0063] (6) One embodiment of the wiring board according to the present disclosure is the wiring board of (5) above, wherein the first insulating base has a third notch portion cut out from the first top surface to the first side surface and the second side surface, the second grounding conductor covers a third wall surface and a third bottom surface of the third notch portion, and the third notch portion has a dimension in the first direction larger than the first notch portion and the second notch portion.

[0064] (7) One embodiment of the wiring board according to the present disclosure is the wiring board of any one of (1) to (6) above, wherein at least one of the corners between the first wall surface and the first side surface and the corners between the second wall surface and the first side surface is a C-surface that is not covered by the first ground conductor.

[0065] (8) One embodiment of the wiring board according to the present disclosure is the wiring board of any one of (1) to (7) above, further comprising a second insulating base positioned on the first upper surface and spaced apart from the first side surface, and the first ground conductor has a third portion whose width increases as it approaches the second insulating base.

[0066] (9) One embodiment of the wiring board according to the present disclosure is the wiring board of any of (1) to (8) above, further comprising a second insulating base located on the first upper surface and spaced apart from the first side surface, the first grounding conductor being in contact with the second insulating base, and the width of the first grounding conductor at the position where it is in contact with the second insulating base being wider than the width of the first grounding conductor at the position where it is in contact with the first side surface.

[0067] (10) One embodiment of the wiring board according to the present disclosure is the wiring board of any of (1) to (9) above, wherein the first insulating base has a recess that opens to the first upper surface, the recess is located in contact with an edge of the first ground conductor in the first direction, and has a fourth wall surface and a fourth bottom surface, and the first ground conductor covers at least a portion of the fourth wall surface and the fourth bottom surface.

[0068] (11) One embodiment of a wiring board according to the present disclosure is the wiring board of any of (1) to (10) above, comprising: a third signal conductor located on the opposite side of the first ground conductor across the first signal conductor; a third ground conductor located on the opposite side of the first signal conductor across the third signal conductor; a fourth signal conductor located on the opposite side of the first ground conductor across the second signal conductor; and a fourth ground conductor located on the opposite side of the second signal conductor across the fourth signal conductor.

[0069] (12) 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 any one of the wiring boards (1) to (11) above joined to the frame body.

[0070] (13) One embodiment of an electronic module according to the present disclosure comprises: an electronic component storage package according to (12) 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.

[0071] 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.

[0072] REFERENCE SIGNS LIST 10 Wiring board 20 First insulating base 201 First upper surface 202 First side surface 203 Second side surface 204 Third side surface 21 First notch portion 211 First wall surface 212 First bottom surface 22 Second notch portion 221 Second wall surface 222 Second bottom surface 23 Third notch portion 231 Third wall surface 232 Third bottom surface 24 Recess 25 Fifth notch portion 251 Fifth wall surface 252 Fifth bottom surface 26 First slit 27 Second slit 30 Second insulating base 41 First ground conductor 411 First portion 412 Second portion 413 Third portion 42 Second ground conductor 43 Third ground conductor 44 Fourth ground conductor 45 Fifth ground conductor 46 Ground via conductor 51 First signal conductor 52 Second signal conductor 53 Third signal conductor 54 Fourth signal conductor 61 First coated portion 62 Second coated portion 70 Electronic component storage package 71 Substrate 72 Frame 721 Light-transmitting portion 73 Seal ring 80 Electronic module 81 Mounting member 82 Electronic component 83 Bonding wire 84 Lid

Claims

1. A wiring board comprising: a first insulating base having a first top surface and a first side surface connected to the first top surface; a first signal conductor and a second signal conductor positioned side by side on the first top surface in a first direction along the first side surface in a plan view; and a first ground conductor positioned on the first top surface between the first signal conductor and the second signal conductor and in contact with the first side surface, wherein the first insulating base has a first notch portion and a second notch portion cut out from the first top surface where the first ground conductor is located to the first side surface, and the first ground conductor covers a first wall surface of the first notch portion and a second wall surface of the second notch portion.

2. The wiring board according to claim 1, wherein the first ground conductor covers a first bottom surface of the first cutout portion and a second bottom surface of the second cutout portion.

3. A wiring board as described in claim 1 or 2, wherein, on a line overlapping with the first side surface in a plan view, the distance between a first end of the first ground conductor on the side of the first signal conductor and the first notch is smaller than the distance between the center of the first ground conductor and the first notch, and on a line overlapping with the first side surface in a plan view, the distance between a second end of the first ground conductor on the side of the second signal conductor and the second notch is smaller than the distance between the center of the first ground conductor and the second notch.

4. A wiring board as described in any one of claims 1 to 3, wherein the first ground conductor has a first portion that is in contact with the first side surface and whose width narrows with increasing distance from the first side surface, and a second portion that is connected to the first portion and has a constant width, and at least a portion of the first cutout portion and at least a portion of the second cutout portion protrude in the first direction beyond the second portion.

5. A wiring board according to any one of claims 1 to 4, wherein the first insulating base has a second side surface connected to the first upper surface and the first side surface, and further comprises a second ground conductor located on the first upper surface and in contact with the first side surface and the second side surface.

6. The wiring board described in claim 5, wherein the first insulating base has a third notch portion cut out from the first top surface to the first side surface and the second side surface, the second grounding conductor covers a third wall surface and a third bottom surface of the third notch portion, and the third notch portion has a dimension in the first direction larger than the first notch portion and the second notch portion.

7. A wiring board according to any one of claims 1 to 6, wherein at least one of a corner between the first wall surface and the first side surface and a corner between the second wall surface and the first side surface is a C-surface that is not covered by the first ground conductor.

8. A wiring board as claimed in any one of claims 1 to 7, further comprising a second insulating base located on the first upper surface and spaced apart from the first side surface, and wherein the first ground conductor has a third portion whose width increases as it approaches the second insulating base.

9. A wiring board as described in any one of claims 1 to 8, further comprising a second insulating base located on the first upper surface and spaced apart from the first side surface, the first ground conductor being in contact with the second insulating base, and the width of the first ground conductor at the position where it is in contact with the second insulating base being wider than the width of the first ground conductor at the position where it is in contact with the first side surface.

10. A wiring board as described in any one of claims 1 to 9, wherein the first insulating base has a recess that opens to the first upper surface, the recess is located in contact with an edge of the first ground conductor in the first direction, and has a fourth wall surface and a fourth bottom surface, and the first ground conductor covers at least a portion of the fourth wall surface and the fourth bottom surface.

11. A wiring board as claimed in any one of claims 1 to 10, comprising: a third signal conductor located on the opposite side of the first ground conductor across the first signal conductor; a third ground conductor located on the opposite side of the first signal conductor across the third signal conductor; a fourth signal conductor located on the opposite side of the first ground conductor across the second signal conductor; and a fourth ground conductor located on the opposite side of the second signal conductor across the fourth signal conductor.

12. 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 11 joined to said frame body.

13. An electronic module comprising: the package for storing electronic components according to claim 12; 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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