Wiring structure and electronic module

Abstract

This wiring structure comprises: an external substrate; a wiring substrate; a first connection member and a second connection member that connect the external substrate and the wiring substrate; and a joining material for joining the external substrate and the wiring substrate. The external substrate has: a first substrate having a first lateral surface; a first ground conductor; and a first signal conductor. The first ground conductor includes a first upper ground conductor and a first lower ground conductor that is electrically connected to the first upper ground conductor. The wiring substrate has: an insulator having a second lateral surface that is so located as to face the first lateral surface; a second signal conductor; a second ground conductor; and a third ground conductor that is to make electrical contact with the second ground conductor. The third ground conductor is located on the second lateral surface. The first connection member connects the first ground conductor and the second ground conductor to each other. The second connection member connects the first signal conductor and the second signal conductor to each other. The joining material is a conductive paste located on the second lateral surface and electrically contacts the third ground conductor and the first lower ground conductor to each other.

Description

[Technical Field]

[0001] The present disclosure relates to wiring structures and electronic modules. [Background technology]

[0002] In recent years, wireless communication devices and optical communication devices have been required to operate at higher frequencies in order to transmit larger volumes of information at higher speeds. Among these, a structure such as that shown in Patent Document 1 is known as an electronic device for transmitting signals. In the invention described in Patent Document 1, the semiconductor element and the signal wiring conductor are electrically connected by a bonding wire (see, for example, FIG. 6 of Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-115736 Summary of the Invention

[0004] In one embodiment of the present disclosure, (1) a wiring structure includes an external substrate, a wiring substrate, a connection member that electrically connects the external substrate and the wiring substrate, and a bonding material that bonds the external substrate and the wiring substrate. The external substrate includes a first substrate, a first ground conductor, and a first signal conductor. The first substrate includes a first upper surface, a first lower surface opposite the first upper surface, and a first side surface that connects to the first lower surface and the first upper surface. The first ground conductor includes a first upper ground conductor located on the first upper surface and a first lower ground conductor located on the first lower surface and electrically connected to the first upper ground conductor. The first signal conductor is located on the first upper surface. The wiring substrate includes an insulator, a second signal conductor, a second ground conductor, and a third ground conductor. The insulator includes a second upper surface, a second lower surface opposite the second upper surface, and a second side surface that connects to the second lower surface and the second upper surface and faces the first side surface. The second ground conductor is located on the second upper surface and extends in a first direction away from the second side surface. The third ground conductor is electrically connected to the second ground conductor. The third ground conductor is located on the second side surface, spaced apart from the second upper surface. The second signal conductor is located on the second upper surface. The connecting member has a first connecting member and a second connecting member. The first connecting member electrically connects the first ground conductor and the second ground conductor. The second connecting member electrically connects the first signal conductor and the second signal conductor. The bonding material is a conductive paste located on the second side surface. The bonding material electrically connects the third ground conductor and the first lower ground conductor.

[0005] (2) In the wiring structure of (1) above, the insulator further has a first opening having a first opening on a second side surface. The first opening has a first inner wall surface continuous with the second side surface. The third ground conductor includes a first region located on the first inner wall surface. The bonding material is located in the first opening. In addition, the bonding material electrically connects the first region and the first lower ground conductor.

[0006] (3) In the wiring structure of (2) above, the first opening is located on the second side surface and spaced apart from the second upper surface.

[0007] (4) In the wiring structure of (1) to (3) above, the bonding material is located on the second side surface with a gap between it and the second upper surface.

[0008] (5) In the wiring structure of (2) to (4) above, the first opening is positioned so as to overlap the second ground conductor in a plan view perpendicular to the second upper surface.

[0009] (6) In the wiring structure of (2) to (5) above, the wiring board further includes a fourth ground conductor located within the insulator. The fourth ground conductor is electrically connected to the second ground conductor. The insulator further includes a second opening having a second opening on a second side surface. The second opening has a second inner wall surface continuous with the second side surface. The second opening is located apart from the first opening on the second side surface. The third ground conductor further includes a second region located on the second inner wall surface. The fourth ground conductor is continuous with the first region and the second region.

[0010] (7) In the wiring structure of any one of (2) to (6), the wiring substrate further includes a fifth ground conductor located within the insulator. The fifth ground conductor is electrically connected to the second ground conductor. The second side surface includes a second upper side surface connected to the second top surface and a second lower side surface spaced from the second top surface and connected to the second upper side surface. The first opening portion has a first opening in the second lower side surface. The fifth ground conductor is located on the second side surface between the second upper side surface and the second lower side surface. The fifth ground conductor is continuous with the first region. The bonding material is located on the second side surface with a gap between it and the fifth ground conductor.

[0011] (8) In the wiring structure of (7) above, in a plan view perpendicular to the first top surface, the distance L1 between the second upper side surface and the first side surface is equal to or less than the distance L2 between the second lower side surface and the first side surface.

[0012] (9) The wiring structure of any one of (1) to (8) further includes a base having a third upper surface. The first lower surface of the external substrate is located on the third upper surface. The bonding material bonds the first lower ground conductor and the base.

[0013] (10) In the wiring structure of (9), the base has a third side surface facing the second side surface, and in a plan view perpendicular to the first top surface, the minimum distance between the third side surface and the second side surface is equal to or greater than the minimum distance between the first side surface and the second side surface.

[0014] (11) In the wiring structure of any one of (1) to (10) above, the connecting member is a wire whose main component is a metal material.

[0015] (12) In the wiring structure of any one of (1) to (11) above, the bonding material contains silver epoxy resin.

[0016] (13) An electronic module according to an embodiment of the present disclosure includes the wiring structure of (1) to (12) above, a base, a frame, and a lid. The base has the wiring structure mounted on its upper surface. The frame is located on the upper surface of the base. The lid is located above the frame. The external substrate is an electronic circuit board. The external substrate is surrounded by the wiring board, the frame, and the lid. [Brief explanation of the drawings]

[0017] [Figure 1] FIG. 1 is a perspective view of a wiring structure according to an embodiment of the present disclosure. [Figure 2] FIG. 1 is a perspective view of an insulator according to an embodiment of the present disclosure. [Figure 3] 2 is a view of the wiring structure shown in FIG. 1 taken along Y1-Y1. [Figure 4] FIG. 1 is a plan view of a wiring structure according to an embodiment of the present disclosure. [Figure 5] 1 is an exploded perspective view of an electronic module including a wiring structure according to an embodiment of the present disclosure; DETAILED DESCRIPTION OF THE INVENTION

[0018] <Configuration of wiring structure> An embodiment of the present disclosure will be described below with reference to the drawings. While either direction of the wiring structure may be considered upward or downward, for convenience, a Cartesian coordinate system xyz is defined, with the positive z-direction being considered upward. In this disclosure, a plan view is a concept that includes a planar perspective view. The direction perpendicular to the first upper surface 11a refers to, for example, the z-direction in the drawings. In FIG. 4, the second lower side surface 22c2, the first inner wall surface 2211, the second inner wall surface 2222, and the third side surface 101c are shown transparently with dotted lines.

[0019] 1 to 4, a wiring structure 100 according to an embodiment of the present disclosure will be described. The wiring structure 100 includes an external substrate 1, a wiring substrate 2, a connection member 3 that electrically connects the external substrate 1 and the wiring substrate 2, and a bonding material 4 that bonds the external substrate 1 and the wiring substrate 2 together.

[0020] As shown in FIG. 1 , the external substrate 1 includes a first substrate 11, a first ground conductor G1, and a first signal conductor S1. The external substrate 1 may be, for example, an electronic circuit board that processes signals, such as converting optical signals to electrical signals or electrical signals to optical signals. The external substrate 1 may also be a flexible printed circuit (FPC). In the present disclosure, the concept of an electronic circuit board includes optical semiconductor elements such as semiconductor lasers (LDs) or photodiodes (PDs), semiconductor integrated circuit elements, and sensor elements such as optical sensors. When the external substrate 1 is an optical semiconductor element, it may be formed of a semiconductor material such as gallium arsenide or gallium nitride.

[0021] As shown in FIGS. 1 to 4, first substrate 11 includes a first upper surface 11a, a first lower surface 11b opposite to first upper surface 11a, and a first side surface 11c connecting first lower surface 11b and first upper surface 11a. Examples of materials that can be used for first substrate 11 include ceramic materials such as aluminum oxide sintered body, mullite sintered body, silicon carbide sintered body, aluminum nitride sintered body, and silicon nitride sintered body, as well as dielectric materials such as glass ceramic materials. First substrate 11 may have a structure in which multiple insulating layers are stacked, or may be a single layer. Furthermore, when external substrate 1 is an electronic circuit board, examples of materials that can be used for first substrate 11 include aluminum nitride and a copper-tungsten alloy.

[0022] As shown in FIG. 1, the first ground conductor G1 includes a first upper ground conductor G1a located on the first upper surface 11a and a first lower ground conductor G1b located on the first lower surface 11b and electrically connected to the first upper ground conductor G1a. In one embodiment, the first upper ground conductor G1a is located on the first upper surface 11a and extends in the x-direction. Examples of materials for the first ground conductor G1 include metal materials such as gold, silver, copper, nickel, tungsten, molybdenum, and manganese. The first ground conductor G1 may be formed by sintering a metal paste on the first upper surface 11a or by using a thin film formation technique such as a vapor deposition method or a sputtering method. The first ground conductor G1 has a width of 0.05 mm to 2 mm and a length of 1.5 mm to 25 mm, for example. The thickness of the first ground conductor G1 is 0.01 mm to 0.1 mm, for example. The width, length, and thickness of the first ground conductor G1 referred to here can be the dimensions of the first ground conductor G1 in the y direction, the x direction, and the z direction, respectively. The widths, lengths, and thicknesses of the first signal conductor S1, the second signal conductor S2, and the second ground conductor G2, which will be described later, can also be defined in a similar manner.

[0023] 3, in one embodiment, the first upper ground conductor G1a and the first lower ground conductor G1b are electrically connected by a first via V1 provided in the first substrate 11. As long as the first upper ground conductor G1a and the first lower ground conductor G1b can be electrically connected, the first upper ground conductor G1a and the first lower ground conductor G1b may be electrically connected by, for example, providing a conductive film on the first side surface 11c.

[0024] The first signal conductor S1 is located on the first upper surface 11a. In one embodiment, the first signal conductor S1 is located alongside the first upper ground conductor G1a. This configuration facilitates impedance adjustment and reduces signal loss. The material of the first signal conductor S1 may be the same as or different from the material of the first ground conductor G1, and examples thereof include materials similar to the materials of the first ground conductor G1 described above. The first signal conductor S1 may also be formed by the same method as the first ground conductor G1 described above. The first signal conductor S1 has a width of 0.05 mm to 2 mm and a length of 1.5 mm to 25 mm, for example. The thickness of the first signal conductor S1 is 0.01 mm to 0.1 mm, for example.

[0025] The wiring board 2 has an insulator 22, a second signal conductor S2, a second ground conductor G2, and a third ground conductor G3. Although not shown, the wiring board 2 is electrically connected to the external board 1, and may have further wires, lead terminals, flexible substrates, etc. connected to the side not facing the external board 1. With this configuration, the wiring board 2 can be used as an input / output terminal for transmitting and receiving electrical signals in the electronic module 10.

[0026] 2 to 4, the insulator 22 includes a second upper surface 22a, a second lower surface 22b opposite the second upper surface 22a, and a second side surface 22c connected to the second lower surface 22b and the second upper surface 22a and facing the first side surface 11c. Examples of materials that can be used for the insulator 22 include ceramic materials such as aluminum oxide sintered body, mullite sintered body, silicon carbide sintered body, aluminum nitride sintered body, and silicon nitride sintered body, as well as dielectric materials such as glass ceramic materials. The material may be the same as or different from that of the first substrate 11.

[0027] Furthermore, the insulator 22 may be configured with multiple layers of dielectric material laminated together, or may be a single layer. The size of the insulator 22 in plan view is, for example, 4 mm × 4 mm to 50 mm × 50 mm, and the thickness is 0.5 mm to 10 mm. When the insulator 22 is configured with multiple layers, multiple conductors such as wiring formed of metal paste or the like may be positioned between the layers.

[0028] The second ground conductor G2 is located on the second upper surface 22a and extends in the positive direction of the x-axis away from the second side surface 22c. The material of the second ground conductor G2 may be the same as or different from the material of the first ground conductor G1, and may be, for example, the same material as the material of the first ground conductor G1 described above. The second ground conductor G2 may also be formed by the same method as the first ground conductor G1 described above. The second ground conductor G2 has a width of 0.05 mm to 2 mm and a length of 1.5 mm to 25 mm, for example. The thickness of the second ground conductor G2 is 0.01 mm to 0.1 mm, for example.

[0029] An insulating film made of ceramic (e.g., alumina coating) or resin may be located on the first upper ground conductor G1a, the first signal conductor S1, the second ground conductor G2, and the second signal conductor S2. The insulating film may be provided on the first upper ground conductor G1a, the first signal conductor S1, the second ground conductor G2, and the second signal conductor S2 by screen printing. Alternatively, the insulating film may be located only on a portion of each signal conductor. This configuration can reduce the possibility of a short circuit between the first upper ground conductor G1a and the first signal conductor S1. The same effect as above can be achieved with the second ground conductor G2 and the second signal conductor S2 by providing an insulating film thereon.

[0030] As shown in FIGS. 2 and 3 , the third ground conductor G3 is electrically connected to the second ground conductor G2. The third ground conductor G3 is located on the second side surface 22c, spaced apart from the second upper surface 22a. The material of the third ground conductor G3 may be the same as or different from the material of the second ground conductor G2, and may be, for example, the same material as the material of the second ground conductor G2 described above. The third ground conductor G3 may be formed by sintering a metal paste on the second side surface 22c, or may be formed using a thin-film formation technique such as a vapor deposition method or a sputtering method. In one embodiment, the third ground conductor G3 is electrically connected to the second ground conductor G2 through a second via V2 formed in the insulator 22 and a fifth ground conductor G5 (described later).

[0031] As shown in FIGS. 1, 2, and 3, the second signal conductor S2 is located on the second upper surface 22a. The material of the second signal conductor S2 may be the same as or different from the material of the first ground conductor G1, and may be, for example, the same material as the first ground conductor G1 described above. The second signal conductor S2 may also be formed by the same method as the first ground conductor G1 described above. The second signal conductor S2 has a width of, for example, 0.05 mm to 2 mm and a length of, for example, 1.5 mm to 25 mm. The thickness of the second signal conductor S2 is, for example, 0.01 mm to 0.1 mm. In one embodiment, the second signal conductor S2 is located alongside the second ground conductor G2, and therefore the second signal conductor S2 serving as a signal wiring can have a coplanar structure. The coplanar structure enables smooth transmission of high-frequency signals.

[0032] In addition, in one embodiment, the second signal conductor S2 and the second ground conductor G2 are positioned to extend parallel to each other, but they do not necessarily have to be parallel, and the second signal conductor S2 and the second ground conductor G2 may move apart or approach each other along the way. In other words, the distance between the second signal conductor S2 and the second ground conductor G2 in the y direction may change along the way. Furthermore, the second signal conductor S2 and the second ground conductor G2 may be bent along the way.

[0033] 2 and 4, the second signal conductor S2 may have a connection portion S2e, a first portion S2a, and a line portion S2b. In this case, a second connection member 32, which will be described later, is connected to the connection portion S2e. The line portion S2b extends in the x-direction. The first portion S2a is located between the line portion S2b and the connection portion S2e. The width of the first portion S2a may be smaller than the width of the first line portion S2b. This configuration can increase the inductance component in the second signal conductor S2. Furthermore, the width of the connection portion S2e may be greater than that of the line portion S2b. With this configuration, it is possible to easily connect the second connection member 32.

[0034] 4, in one embodiment, the second signal conductor S2 and the second ground conductor G2 extend to the second side surface 22c in a plan view from the z direction. This configuration reduces the size and length of the connection member 3, thereby reducing the possibility of impedance fluctuations at the connection between the first signal conductor S1 and the second signal conductor S2 and the connection between the first ground conductor G1 and the second ground conductor G2. The second signal conductor S2 and the second ground conductor G2 do not necessarily need to extend to the second side surface 22c. The second signal conductor S2 and the second ground conductor G2 may be spaced apart from the second side surface 22c in the x direction in a plan view from the z direction. This configuration reduces the possibility of damage to the second signal conductor S2 and the second ground conductor G2 when manufacturing the wiring board 2 by dicing.

[0035] As shown in FIGS. 1 and 3 , the connection member 3 includes a first connection member 31 and a second connection member 32. The first connection member 31 electrically connects the first ground conductor G1 and the second ground conductor G2. The second connection member 32 electrically connects the first signal conductor S1 and the second signal conductor S2. In one embodiment, the first connection member 31 and the second connection member 32 may be wires mainly composed of a metal material. In this case, even if the heights (lengths in the z direction) of the first upper surface 11a and the second upper surface 22a are different in plan view from the y direction, the external substrate 1 and the wiring substrate 2 can be easily connected by the connection member 3. The connection member 3 may also be a flexible substrate. In this case, conductor lines formed on the flexible substrate can be regarded as the first connection member 31 and the second connection member 32. Alternatively, either the first connection member 31 or the second connection member 32 may be a flexible substrate, and the other may be a wire.

[0036] 1, when the wiring board 2 has the third signal conductor S3 and the sixth ground conductor G6 located on the second upper surface 22a, the connection member 3 may further include a third connection member 33 and a fourth connection member 34. Furthermore, the external board 1 may further include a fourth signal conductor S4 and a seventh ground conductor G7 located on the first upper surface 11a. In this case, the third connection member 33 electrically connects the third signal conductor S3 and the fourth signal conductor S4, and the fourth connection member 34 electrically connects the sixth ground conductor G6 and the seventh ground conductor G7. With this configuration, the second signal conductor S2 and the third signal conductor S3 can be regarded as a pair of differential signal lines, and the wiring board 2 can transmit differential signals.

[0037] The wiring board 2 may further include an eighth ground conductor G8 located between the second signal conductor S2 and the third signal conductor S3. If the second signal conductor S2 and the third signal conductor S3 have a wiring pattern with a curved portion, the influence of a phase shift between the second signal conductor S2 and the third signal conductor S3 can be reduced. This allows for good transmission of high-frequency signals.

[0038] The bonding material 4 is a conductive paste located on the second side surface 22c. The bonding material 4 may also electrically connect the third ground conductor G3 and the first lower ground conductor G1b. In FIG. 4, the connecting member 3 is omitted. In one embodiment, the bonding material 4 may contain silver epoxy resin. When the bonding material 4 contains silver epoxy resin, the silver epoxy resin has a higher viscosity than solder or brazing material and is therefore less likely to flow off. This makes it easier to position the bonding material 4 at a desired position. The bonding material 4 may also be solder, brazing material, or the like.

[0039] As described above, the third ground conductor G3 and the first lower ground conductor G1b are electrically connected via the bonding material 4, thereby eliminating the deviation in ground potential between the external substrate 1 and the wiring substrate 2 and strengthening the grounding state. This improves the crosstalk characteristics during signal transmission in the second signal conductor S2. Furthermore, the above-described configuration allows the external substrate 1 to be positioned closer to the wiring substrate 2, thereby further miniaturizing the wiring structure 100.

[0040] As shown in FIGS. 2 and 3 , the insulator 22 may further include a first opening 221 having a first opening O1 on the second side surface 22c. In this case, the first opening 221 has a first inner wall surface 2211 that is continuous with the second side surface 22c. The third ground conductor G3 includes a first region G31 located on the first inner wall surface 2211. The bonding material 4 is located in the first opening 221. The bonding material 4 electrically connects the first region G31 and the first lower ground conductor G1b. That is, the bonding material 4 is located within the first opening 221 in a plan view from the z direction. This configuration enhances the grounding state of the high-frequency signal wiring between the external substrate 1 and the wiring substrate 2. Furthermore, the bonding strength between the external substrate 1 and the wiring substrate 2 can be improved.

[0041] In one embodiment, the first region G31 of the third ground conductor G3 is a so-called castellation formed by applying metal paste to the first inner wall surface 2211 of the first opening 221, but the third ground conductor G3 may also have the shape of a divided via filled with metal paste on the first inner wall surface 2211.

[0042] As shown in FIGS. 2 and 3 , the first opening 221 may be located on the second side surface 22c with a gap between it and the second upper surface 22a. This configuration reduces the possibility of the bonding material 4 located in the first opening 221 shorting out with the second signal conductor S2 or the connecting member 3 on the second upper surface 22a. The first opening 221 is not limited to the above-described configuration and may have a notched shape extending from the second upper surface 22a to the second side surface 22c. In this case, the grounding state of the high-frequency signal wiring can be further strengthened. In a plan view from the z direction, the first opening 221 may have a rectangular shape, an arc shape, or a rectangular shape with rounded corners.

[0043] 3, the bonding material 4 may be located on the second side surface 22c with a gap between it and the second upper surface 22a. This configuration can reduce the possibility that the bonding material 4 will come into contact with the connection member 3 and cause a short circuit.

[0044] The first opening 221 may be positioned so as to overlap the second ground conductor G2 in a plan view in the z direction. That is, the first opening 221 having a first inner wall surface 2211 on which the first region G31 of the third ground conductor G3 is formed and which functions as a castellation may be formed below the second ground conductor G2.

[0045] 4, in one embodiment, the width of the first opening 221 in plan view in the z direction (size in the y direction) may be equal to or smaller than the width of the second ground conductor G2. Furthermore, without being limited to the above embodiment, the width of the first opening 221 may be larger than the width of the second signal conductor S2.

[0046] As shown in FIGS. 2 and 3 , the wiring board 2 may further include a fourth ground conductor G4 located within the insulator 22. In this case, the fourth ground conductor G4 is electrically connected to the second ground conductor G2. The fourth ground conductor G4 may be an inner ground conductor layer or may be located in the bottom layer of the insulator 22. The insulator 22 further includes a second opening 222 having a second opening O2 on the second side surface 22c. The second opening 222 has a second inner wall surface 2222 continuous with the second side surface 22c. The second opening 222 is located apart from the first opening 221 on the second side surface 22c. The third ground conductor G3 further includes a second region G32 located on the second inner wall surface 2222. The fourth ground conductor G4 is continuous with the first region G31 and the second region G32. This configuration enhances the grounding state of the wiring board 2. In one embodiment, the second opening 222 is positioned alongside the first opening 221 on the second lower side surface 22c2 described below, but the first opening 221 and the second opening 222 do not necessarily have to be positioned alongside each other on the second lower side surface 22c2, and may be positioned offset in the z or y direction.

[0047] Furthermore, in one embodiment, the bonding material 4 is located in the first opening 221 and the second opening 222. This increases the bonding area in the wiring board 2, thereby improving the bonding strength between the external board 1 and the wiring board 2. Note that the bonding material 4 located in the first opening 221 and the bonding material 4 located in the second opening 222 do not necessarily need to be located contiguously, and the bonding material 4 located in the first opening 221 and the bonding material 4 located in the second opening 222 may be located separately.

[0048] As shown in FIG. 4, when the wiring board 2 has a sixth ground conductor G6 located on the second upper surface 22a, the second opening 222 may be positioned so as to overlap the sixth ground conductor G6 in a planar view from the z direction.

[0049] As shown in FIGS. 2 and 3, the wiring board 2 may further include a fifth ground conductor G5 located within the insulator 22. In this case, the fifth ground conductor G5 is an inner ground conductor layer and is electrically connected to the second ground conductor G2. The second side surface 22c has a second upper side surface 22c1 connected to the second top surface 22a and a second lower side surface 22c2 spaced from the second top surface 22a and connected to the second upper side surface 22c1. The first opening 221 has a first opening in the second lower side surface. The fifth ground conductor G5 is located on the second side surface 22c between the second upper side surface 22c1 and the second lower side surface 22c2. The fifth ground conductor G5 is continuous with the first region G31. The bonding material 4 may be located on the second side surface 22c with a gap between it and the fifth ground conductor G5. The ground potential can be strengthened by positioning the fifth ground conductor G5 inside the insulator 22. Furthermore, the bonding material 4 is positioned on the second side surface 22c with a gap between it and the fifth ground conductor G5, thereby reducing the possibility of the bonding material 4 shorting out with the second signal conductor S2 or the connection member 3 on the second upper surface 22a.

[0050] As shown in FIGS. 3 and 4 , in a plan view from the z direction, the distance L1 between the second upper side surface 22c1 and the first side surface 11c may be equal to or less than the distance L2 between the second lower side surface 22c2 and the first side surface 11c. That is, the second side surface 22c may have a stepped shape. In other words, in a plan view from the z direction, the second lower side surface 22c2 may be farther from the first side surface 11c in the positive direction of the x axis than the second upper side surface 22c1. This configuration reduces the possibility of the insulator 22 colliding with the external substrate 1 when some layers protrude in the negative x direction due to misalignment when forming the insulator 22 by stacking dielectric materials. This reduces the possibility of the external substrate 1 being damaged.

[0051] As shown in FIG. 3, the external substrate 1 may further include a pedestal 101 having a third upper surface 101a. In this case, the first lower surface 11b of the external substrate 1 is located on the third upper surface 101a. The bonding material 4 may bond the first lower ground conductor G1b and the pedestal 101 together. This configuration facilitates height adjustment of the external substrate 1 in the z direction and facilitates bonding of the external substrate 1 and the wiring substrate 2 using the connection member 3. After applying the bonding material 4 to the first lower surface 11b of the external substrate 1, the external substrate 1 is bonded to the pedestal 101 and the second side surface 22c, thereby completing the wiring structure 100 of one embodiment.

[0052] As shown in FIG. 3, the base 101 may have a third side surface 101c facing the second side surface 22c. In a plan view from the z direction, the minimum distance between the third side surface 101c and the second side surface 22c is equal to or greater than the minimum distance between the first side surface 11c and the second side surface 22c. This configuration facilitates the bonding material 4 to form a fillet from the first lower surface 11b to the third side surface 101c, thereby improving the bonding strength between the external substrate 1 and the base 101. As shown in FIG. 3, in one embodiment, the minimum distance between the third side surface 101c and the second side surface 22c is, for example, the distance L3 between the third side surface 101c and the second upper side surface 22c1. In another embodiment, the minimum distance between the first side surface 11c and the second side surface 22c is, for example, the distance L1 between the first side surface 11c and the second upper side surface 22c1.

[0053] <Electronic module configuration> An electronic module 10 according to an embodiment of the present disclosure includes a wiring structure 100, a base 102, a frame 103, and a lid 106. The electronic module 10 may further include a seal ring 105. In one embodiment, the external substrate 1 is an electronic circuit board. In a plan view from the z direction, the external substrate 1 is surrounded by the wiring substrate 2, the frame 103, and the lid 106.

[0054] As shown in FIG. 5, the wiring board 2 may be integrated with a wall portion 104 that is U-shaped when viewed from above in the z direction. The base 102 has an upper surface, and the wiring structure 100 is mounted on the upper surface. The base 102 is, for example, rectangular in plan view, with dimensions of 10 mm × 10 mm to 50 mm × 50 mm and a thickness of 0.5 mm to 20 mm. Examples of materials for the base 102 include metal materials such as copper, iron, tungsten, molybdenum, nickel, and cobalt, and alloys containing these metal materials. In this case, the base 102 may be a single metal plate or a laminate formed by stacking multiple metal plates. Furthermore, when the base 102 is made of the above metal materials, a plating layer of nickel, gold, or the like may be formed on the surface of the base 102 using electroplating or electroless plating to reduce oxidation corrosion. The material of the base 102 may be an insulating material, such as an aluminum oxide sintered body, a mullite sintered body, a silicon carbide sintered body, an aluminum nitride sintered body, a silicon nitride sintered body, or a ceramic material such as glass ceramics.

[0055] The frame 103 is located on the upper surface of the base 102 and protects the external substrate 1 located inside in a plan view. As shown in FIG. 5 , in one embodiment, the upper surface of the base 102 is surrounded by the frame 103 and the wall 104. In other words, the frame 103 and the wall 104 are positioned so as to surround the external substrate 1. In this manner, the frame 103 does not have to surround the entire outer edge of the upper surface of the base 102. Furthermore, in one embodiment, the frame 103 is positioned along the outer edge of the upper surface of the base 102, but the frame 103 may be positioned inside the outer edge of the upper surface of the base 102.

[0056] The material of the frame 103 may be, for example, a metal material such as copper, iron, tungsten, molybdenum, nickel, or cobalt, or an alloy containing any of these metal materials. The material of the frame 103 may also be an insulating material, such as an aluminum oxide sintered body, a mullite sintered body, a silicon carbide sintered body, an aluminum nitride sintered body, a silicon nitride sintered body, or a ceramic material such as glass ceramics.

[0057] The lid 106 is located above the frame 103. The lid 106 protects the external substrate 1 together with the frame 103. The lid 106 has, for example, a rectangular shape in plan view, with dimensions of 10 mm × 10 mm to 50 mm × 50 mm and a thickness of 0.5 mm to 2 mm. Examples of materials for the lid 106 include metal materials such as iron, copper, nickel, chromium, cobalt, molybdenum, and tungsten, as well as alloys made up of a combination of these metal materials. The metal member that constitutes the lid 106 can be produced by subjecting an ingot of such a metal material to metalworking methods such as rolling and punching.

[0058] The seal ring 105 functions to join the lid 106 and the frame 103. The seal ring 105 is located on the frame 103. Examples of materials for the seal ring 105 include metal materials such as iron, copper, silver, nickel, chromium, cobalt, molybdenum, and tungsten, and alloys made by combining a plurality of these metal materials. Note that if the seal ring 105 is not provided on the frame 103, the lid 106 may be joined via an adhesive such as solder, brazing material, glass, or resin adhesive. It should be noted that various combinations of the features in one embodiment are not limited to the examples of the above-described embodiment, and combinations of the respective embodiments are also possible.

[0059] The wiring structure according to the embodiment has the above-described configuration, which makes it possible to strengthen the ground potential, thereby reducing the possibility of crosstalk occurring during signal transmission. [Industrial Applicability]

[0060] The present disclosure can be used as a wiring structure and an electronic module. [Explanation of symbols]

[0061] 1 External board 11 First board 11a 1st top surface 11b 1st bottom surface 11c 1st side 2. Wiring board 22 Insulators 22a 2nd top surface 22b 2nd bottom surface 22c 2nd side 22c1 2nd upper side 22c2 2nd lower side 221 First Opening O1 First opening 2211 First inner wall 222 Second Opening O2 2nd opening 2222 Second inner wall 3 Connecting members 31 first connecting member 32 second connecting member 33 Third connecting member 34 Fourth connecting member 4 Bonding material V1 First via V2 Second via S1 First signal conductor S2 Second signal conductor S3 Third signal conductor S4 4th signal conductor G1 First ground conductor G1a First upper ground conductor G1b First lower grounding conductor G2 Second ground conductor G3 Third Ground Conductor G31 1st area G32 2nd area G4 Fourth Ground Conductor G5 Fifth ground conductor G6 Sixth Ground Conductor G7 Seventh ground conductor G8 Eighth Ground Conductor L1 Distance between the first side and the second upper side L2 Distance between the first side and the second lower side L3 Distance between the second and third sides 10 Electronic Module 100 Wiring structure 101 Pedestal 101a 3rd top surface 101c Third side 102 Base 103 Shibe 104 Wall section 105 シールリング 106. Cover

Claims

1. an external substrate; a wiring substrate; a connection member that electrically connects the external substrate and the wiring substrate; and a bonding material that bonds the external substrate and the wiring substrate; The external substrate is a first substrate including a first upper surface, a first lower surface opposite to the first upper surface, and a first side surface connecting the first lower surface and the first upper surface; a first ground conductor including a first upper ground conductor located on the first upper surface and a first lower ground conductor located on the first lower surface and electrically connected to the first upper ground conductor; a first signal conductor located on the first top surface; The wiring board is an insulator including a second upper surface, a second lower surface opposite the second upper surface, and a second side surface connecting the second lower surface and the second upper surface and facing the first side surface; a second ground conductor located on the second top surface and extending in a first direction away from the second side surface; a second signal conductor located on the second top surface; a third ground conductor electrically connected to the second ground conductor and positioned on the second side surface and spaced apart from the second top surface; The connecting member is a first connection member that electrically connects the first ground conductor and the second ground conductor; a second connection member that electrically connects the first signal conductor and the second signal conductor, The bonding material is a conductive paste located on the second side surface and electrically connecting the third ground conductor and the first lower ground conductor; Wiring structure.

2. the insulator further has a first opening having a first opening on the second side; the first opening has a first inner wall surface that is continuous with the second side surface, the third ground conductor includes a first region located on the first inner wall surface, The wiring structure according to claim 1 , wherein the bonding material is located in the first opening and electrically connects the first region and the first underlying ground conductor.

3. The wiring structure according to claim 2 , wherein the first opening is located on the second side surface and spaced apart from the second upper surface.

4. The wiring structure according to claim 1 , wherein the bonding material is located on the second side surface and spaced apart from the second upper surface.

5. The wiring structure according to claim 2 , wherein the first opening is positioned so as to overlap the second ground conductor in a plan view perpendicular to the second upper surface.

6. the wiring substrate further includes a fourth ground conductor located within the insulator and electrically connected to the second ground conductor; the insulator further has a second opening having a second opening on the second side; the second opening has a second inner wall surface that is continuous with the second side surface and is located apart from the first opening on the second side surface; the third ground conductor further includes a second region located on the second inner wall surface, The wiring structure of claim 2 , wherein the fourth ground conductor is continuous with the first region and the second region.

7. the wiring substrate further includes a fifth ground conductor located within the insulator and electrically connected to the second ground conductor; the second side surface has a second upper side surface connected to the second top surface and a second lower side surface spaced apart from the second top surface and connected to the second upper side surface, The first opening has the first opening on the second lower side, the fifth ground conductor is located on the second side surface between the second upper side surface and the second lower side surface and is continuous with the first region; The wiring structure according to claim 2 , wherein the bonding material is located on the second side surface and spaced apart from the fifth ground conductor.

8. 8. The wiring structure according to claim 7, wherein, in a plan view from a direction perpendicular to the first top surface, a distance L1 between the second upper side surface and the first side surface is less than or equal to a distance L2 between the second lower side surface and the first side surface.

9. a base portion having a third upper surface; the first lower surface of the external substrate is located on the third upper surface; The wiring structure according to claim 1 , wherein the bonding material bonds the first lower ground conductor and the pedestal.

10. the base portion has a third side surface facing the second side surface, The wiring structure according to claim 9, wherein, in a planar view from a direction perpendicular to the first top surface, the minimum value of the distance between the third side surface and the second side surface is equal to or greater than the minimum value of the distance between the first side surface and the second side surface.

11. 2. The wiring structure according to claim 1, wherein the connecting member is a wire whose main component is a metal material.

12. The wiring structure according to claim 1 , wherein the bonding material comprises a silver epoxy resin.

13. The wiring structure according to any one of claims 1 to 12, a base on which the wiring structure is mounted; a frame portion located on the upper surface of the base portion; a lid body positioned on the frame portion, The external substrate is an electronic circuit board, and the electronic module is surrounded by the wiring board, the frame, and the lid.

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