Wiring substrate and package for accommodating electronic component

Abstract

A wiring substrate (10) comprises a first insulating substrate (11) that has a first upper surface, a first conductor (13) that is positioned on the first upper surface, and a second insulating substrate (12) that is positioned on the first upper surface and on the first conductor (13) and that extends in a manner intersecting the first conductor (13). The first conductor (13) has an inner layer part (133) that is positioned between the first insulating substrate (11) and the second insulating substrate (12) and a first surface layer part (131) that is positioned so as not to overlap the second insulating substrate (12). The thickness of the inner layer part (133) is greater than the thickness of the first surface layer part (131).

Description

Wiring Board and Package for Housing Electronic Components

[0001] The present disclosure relates to a wiring board and a package for housing electronic components.

[0002] For example, as disclosed in Patent Document 1, an input / output terminal having a circuit conductor partially sandwiched between a flat plate portion and a standing wall portion is known.

[0003] Japanese Patent Application Laid-Open No. 2003-249596

[0004] The wiring board according to the present disclosure includes a first insulating substrate, a first conductor, and a second insulating substrate. The first insulating substrate has a first upper surface. The first conductor is located on the first upper surface. The second insulating substrate is located on the first upper surface and the first conductor and extends intersecting the first conductor. The first conductor has an inner layer portion and a first surface layer portion. The inner layer portion is located between the first insulating substrate and the second insulating substrate. The first surface layer portion is located without overlapping the second insulating substrate. The thickness of the inner layer portion is larger than the thickness of the first surface layer portion.

[0005] The package for housing electronic components according to the present disclosure includes a substrate, a frame body located on the substrate, and a wiring board joined to the frame body.

[0006] Perspective view of the wiring board. Plan view of the wiring board. Plan perspective view of the wiring board with the second insulating substrate seen through. Plan perspective view of the wiring board with the second insulating substrate and the insulating film seen through. Cross-sectional view of the wiring board at the position A-A in FIG. 2. Perspective view showing another form of the first conductor. Perspective view showing another form of the first conductor. Perspective view showing another form of the first conductor. Perspective view of the package for housing electronic components. Exploded perspective view of the electronic module.

[0007] Hereinafter, embodiments of the present disclosure will be described based on the drawings. However, each of the drawings referred to below is a diagram showing the main members necessary for explaining the embodiments in a simplified manner for convenience of explanation. Therefore, the embodiments of the present disclosure may include any constituent members not shown in each of the drawings referred to. Also, each of the drawings does not necessarily faithfully represent the dimensional ratios of actual members.

[0008] Regarding direction, the direction in which the first upper surface of the wiring board faces is defined as upward, and the opposite direction is defined as downward. Note that the direction in this disclosure does not mean the direction in which the board is actually used. For convenience, each direction is represented using a Cartesian coordinate system XYZ with upward being the positive side of the Z direction. In this disclosure, "plan view" means viewing from above (the positive side of the Z direction), and includes planar perspective.

[0009] In the following descriptions, expressions such as "constant," "orthogonal," "perpendicular," "parallel," and "same" may be used. These expressions do not necessarily strictly mean "constant," "orthogonal," "perpendicular," "parallel," or "same," respectively, and may allow for deviations such as manufacturing precision or installation precision. Numerical ranges indicated using "~" include the numbers before and after them as the lower and upper limits, respectively.

[0010] In a line conductor having an inner layer sandwiched between two insulating substrates and a surface layer located on one insulating substrate and exposed from the other, the current capacity of the entire line conductor was sometimes reduced due to the low current capacity of the inner layer.

[0011] The wiring board and electronic component housing package of this disclosure can increase the overall current capacity of the line conductor.

[0012] [Wiring board] As shown in Figures 1 to 5, the wiring board 10 comprises a first insulating substrate 11, a second insulating substrate 12, and a first conductor 13. The first insulating substrate 11 has a first upper surface 111. The first conductor 13 is located on the first upper surface 111. The second insulating substrate 12 is located on the first upper surface 111 and the first conductor 13, and extends intersecting the first conductor 13. In Figures 3 and 4, the second insulating substrate 12 is shown transparently and indicated by a dashed line.

[0013] As shown in Figures 3 to 5, the first conductor 13 has an inner layer portion 133 located between the first insulating substrate 11 and the second insulating substrate 12, and a first surface layer portion 131 located without overlapping with the second insulating substrate 12. As shown in Figure 5, the thickness of the inner layer portion 133 is greater than the thickness of the first surface layer portion 131.

[0014] The first surface layer 131 may be designed to be wider than the inner layer 133 for impedance adjustment. The first surface layer 131 may also be plated to prevent corrosion. In such cases, if the inner layer 133 has the same thickness as the first surface layer 131, its resistance will be higher than that of the first surface layer 131, and its current capacity will be lower. Therefore, by making the thickness of the inner layer 133 greater than that of the first surface layer 131, the overall current capacity of the first conductor 13 can be increased. Furthermore, by ensuring the first surface layer 131 is not too thick, the possibility of surface irregularities such as pinholes and porosity is reduced. This reduces the possibility of mounting defects when mounting external terminals 24, such as bonding wires, to the first surface layer 131. Because the inner layer 133 is flattened by being compressed by the second insulating substrate 12, surface irregularities are less likely to occur even if it is somewhat thick. Furthermore, even if irregularities were to form on the surface of the inner layer 133, this would not pose a problem because the external terminals 24 are not connected to the inner layer 133.

[0015] The thickness of the inner layer 133 may be 1.2 times or more the thickness of the first surface layer 131. This makes it easier to secure current capacity in the inner layer 133. This effect is particularly effective when the width of the inner layer 133 is smaller than the width of the first surface layer 131. The thickness of the inner layer 133 may be 2 times or less the thickness of the first surface layer 131. This prevents the inner layer 133 from becoming too thick, making it easier to maintain airtightness between the first insulating substrate 11 and the second insulating substrate 12. The thickness of the inner layer 133 is, for example, 10 to 35 μm.

[0016] The thickness of the first surface layer 131 may be 20 μm or less. This makes it less likely for pinholes, porosity, etc. to occur in the first surface layer 131, and reduces the possibility of mounting defects when mounting external terminals 24 such as bonding wires to the first surface layer 131. The thickness of the first surface layer 131 is, for example, 5 μm or more and 20 μm or less.

[0017] As shown in Figures 2 to 5, the first conductor 13 may have a second surface layer 135 located on the opposite side of the first surface layer 131, with the inner layer 133 in between, without overlapping with the second insulating substrate 12. In this case, as shown in Figure 5, the thickness of the inner layer 133 may be greater than the thickness of the second surface layer 135. The second surface layer 135, like the first surface layer 131, may be designed to be wider than the inner layer 133 or may be plated. Here, if the thickness of the inner layer 133 is greater than the thickness of the second surface layer 135, the overall current capacity of the first conductor 13 tends to increase, similar to the case where the thickness of the inner layer 133 is greater than the thickness of the first surface layer 131. The thickness of the second surface layer 135 is, for example, 5 μm or more and 20 μm or less. The thickness of the second surface layer 135 may be the same as the thickness of the first surface layer 131.

[0018] In this disclosure, the thickness of the first conductor 13 refers to the dimension of the first conductor 13 in the vertical direction, and in the figure, it is the dimension of the first conductor 13 in the Z direction. If the first conductor 13 is plated, the thickness of the plating is not included in the thickness of the first conductor 13.

[0019] As shown in Figure 4, the width of the inner layer 133 may be smaller than the width of the first surface layer 131. Since the inner layer 133 is surrounded by dielectrics and resins such as the first insulating substrate 11 and the second insulating substrate 12, the relative permittivity becomes high and the impedance tends to decrease. Therefore, if the width of the inner layer 133 is smaller than the width of the first surface layer 131, the decrease in impedance in the inner layer 133 is reduced, and the impedance can be adjusted appropriately. Similarly, the width of the inner layer 133 may be smaller than the width of the second surface layer 135.

[0020] In this disclosure, the width of the first conductor 13 refers to the dimension of the first conductor 13 in the direction in which the first conductor 13 extends and in the direction perpendicular to the first upper surface 111, and in the figure it is the dimension of the first conductor 13 in the Y direction.

[0021] As shown in Figures 3 to 5, the first conductor 13 may have a first connection portion 132 located between the inner layer portion 133 and the first surface layer portion 131. The first connection portion 132 is a portion whose width changes from the first surface layer portion 131 to the inner layer portion 133. The presence of the first connection portion 132 in the first conductor 13 allows for impedance adjustment in signal transmission between the first surface layer portion 131 and the inner layer portion 133. At least a portion of the first connection portion 132 does not need to overlap with the second insulating substrate 12. In this case, the thickness of the portion of the first connection portion 132 that does not overlap with the second insulating substrate 12 may be greater than the thickness of the first surface layer portion 131. This makes it easier to absorb manufacturing errors so that the portion of the first conductor 13 sandwiched between the first insulating substrate 11 and the second insulating substrate 12 is reliably thick.

[0022] The thickness of the portion of the first connection portion 132 that does not overlap with the second insulating substrate 12 may be greater than the thickness of the inner layer portion 133. The thickness of the portion of the first connection portion 132 that does not overlap with the second insulating substrate 12 is, for example, 1.2 times or more and 1.4 times or less the thickness of the inner layer portion 133.

[0023] Similarly, as shown in Figures 3 to 5, the first conductor 13 may have a second connection portion 134 located between the inner layer portion 133 and the second surface layer portion 135. The second connection portion 134 is a portion whose width changes from the second surface layer portion 135 to the inner layer portion 133. By having the second connection portion 134 in the first conductor 13, impedance adjustment can be performed in signal transmission between the second surface layer portion 135 and the inner layer portion 133. At least a part of the second connection portion 134 does not have to overlap with the second insulating substrate 12. In this case, the thickness of the portion of the second connection portion 134 that does not overlap with the second insulating substrate 12 may be greater than the thickness of the second surface layer portion 135. This makes it easier to absorb manufacturing errors so that the portion of the first conductor 13 sandwiched between the first insulating substrate 11 and the second insulating substrate 12 is reliably thick.

[0024] The thickness of the portion of the second connection portion 134 that does not overlap with the second insulating substrate 12 may be greater than the thickness of the inner layer portion 133. The thickness of the portion of the second connection portion 134 that does not overlap with the second insulating substrate 12 is, for example, 1.2 times or more and 1.4 times or less the thickness of the inner layer portion 133.

[0025] At least a portion of the first connection portion 132 may overlap with the second insulating substrate 12. In this case, the thickness of the portion of the first connection portion 132 that overlaps with the second insulating substrate 12 may be greater than the thickness of the first surface layer portion 131 and the same as the thickness of the inner layer portion 133.

[0026] Similarly, at least a portion of the second connection portion 134 may overlap with the second insulating substrate 12. In this case, the thickness of the portion of the second connection portion 134 that overlaps with the second insulating substrate 12 may be greater than the thickness of the second surface layer portion 135 and the same as the thickness of the inner layer portion 133.

[0027] When the width of the inner layer 133 is smaller than the width of the first surface layer 131, the first connection portion 132 may have a tapered shape, as shown in Figure 4, where the width gradually decreases from the side of the first surface layer 131 to the side of the inner layer 133. This makes it easier to smooth out the change in impedance from the first surface layer 131 to the inner layer 133.

[0028] Similarly, when the width of the inner layer 133 is smaller than the width of the second surface layer 135, the second connection portion 134 may have a tapered shape, as shown in Figure 4, where the width gradually decreases from the side of the second surface layer 135 to the side of the inner layer 133. This makes it easier to smooth out the change in impedance from the second surface layer 135 to the inner layer 133.

[0029] The second insulating substrate 12 may have a first side surface 121 facing the side where the first surface layer 131 is located, and a second side surface 122 facing the side where the second surface layer 135 is located. The first insulating substrate 11 may have a third side surface 112 facing the same side as the first side surface 121 of the second insulating substrate 12, and a fourth side surface 113 facing the same side as the second side surface 122 of the second insulating substrate 12.

[0030] When the first connection portion 132 has a tapered shape in which its width gradually decreases from the side of the first surface portion 131 to the side of the inner layer portion 133, as shown in Figure 4, the first connection portion 132 may be positioned overlapping with the first side surface 121 in a plan view. This makes it easier for the change in impedance to become more gradual near the first side surface 121, where the impedance tends to change abruptly.

[0031] Similarly, when the second connection portion 134 has a tapered shape in which its width gradually decreases from the side of the second surface portion 135 to the side of the inner layer portion 133, the second connection portion 134 may be positioned to overlap with the second side surface 122 in a plan view, as shown in Figure 4. This makes it easier for the change in impedance to become more gradual near the second side surface 122, where the impedance tends to change abruptly.

[0032] As shown in Figures 1 to 5, the wiring board 10 may include an insulating film 14 located on the first upper surface 111. In Figure 4, the insulating film 14 is shown transparently and is indicated by a dashed line.

[0033] The insulating film 14 may have one or more first portions 141 extending along the first side surface 121. At least a portion of the first portion 141 may be located between the first upper surface 111 and the first side surface 121 without overlapping with the first conductor 13 in a plan view. A gap is likely to form between the first insulating substrate 11 and the second insulating substrate 12 due to the influence of the first conductor 13. Here, if at least a portion of the first portion 141 is located between the first upper surface 111 and the first side surface 121 in a location that does not overlap with the first conductor 13 in a plan view, the gap between the first upper surface 111 of the first insulating substrate 11 and the first side surface 121 of the second insulating substrate 12 is sealed, improving airtightness.

[0034] Similarly, the insulating film 14 may have one or more second portions 142 extending along the second side surface 122. At least a portion of the second portion 142 may be located between the first upper surface 111 and the second side surface 122 without overlapping with the first conductor 13 in a plan view. This seals the gap between the first upper surface 111 of the first insulating substrate 11 and the second side surface 122 of the second insulating substrate 12, thereby improving airtightness.

[0035] As shown in Figures 3 and 4, at least a portion of the first part 141 and at least a portion of the second part 142 may be located between the first upper surface 111 and the second insulating substrate 12. This makes it easier for the insulating film 14 to seal the gap between the first insulating substrate 11 and the second insulating substrate 12, even if there are manufacturing errors.

[0036] As shown in Figures 3 and 4, the first part 141 and the second part 142 do not necessarily have to be directly joined to each other. In other words, there may be a region between the first part 141 and the second part 142 where the insulating film 14 is not formed. This reduces the amount of insulating film 14 material required, thus reducing costs. Also, by not providing more insulating film 14 than necessary, the possibility of the insulating film 14 flowing and covering at least one of the first surface layer 131 and the second surface layer 135 when the second insulating substrate 12 is laminated is reduced. This reduces the possibility of impedance matching being misaligned and transmission characteristics being adversely affected. Also, by not providing more insulating film 14 than necessary, the possibility of the insulating film 14 flowing and covering too much of the inner layer 133 is reduced. This reduces the possibility of airtightness being reduced. Note that the first part 141 and the second part 142 do not necessarily have to be directly joined to each other; they may be directly joined to each other.

[0037] As shown in Figures 3 and 4, at least a portion of the insulating film 14 may be located on the inner layer 133. This makes it easier for the insulating film 14 to seal the gap between the first insulating substrate 11 and the second insulating substrate 12, even if there are manufacturing errors.

[0038] When the first conductor 13 has a first connection portion 132, and the first connection portion 132 is positioned to overlap with the first side surface 121 in a plan view, at least a portion of the first part 141 may be located on the first connection portion 132, as shown in Figures 3 and 4. This makes it easier for the insulating film 14 to seal the gap between the first insulating substrate 11 and the second insulating substrate 12, even if there are manufacturing errors.

[0039] Similarly, when the first conductor 13 has a second connection portion 134, and the second connection portion 134 is positioned to overlap with the second side surface 122 in a plan view, at least a portion of the second portion 142 may be located on top of the second connection portion 134, as shown in Figures 3 and 4. This makes it easier for the insulating film 14 to seal the gap between the first insulating substrate 11 and the second insulating substrate 12, even if there are manufacturing errors.

[0040] The first surface layer 131 may be plated with gold plating and / or nickel plating. This makes the first surface layer 131 less susceptible to corrosion. It also increases the likelihood of a lower resistance value for the first surface layer 131. When the first surface layer 131 is plated, the thickness of the plating is, for example, about 2 to 10 μm, and the combined thickness of the first surface layer 131 and the plating is, for example, about 7 to 30 μm.

[0041] Similarly, the second surface layer 135 may be plated with gold plating and / or nickel plating. This makes the second surface layer 135 less susceptible to corrosion. It also increases the likelihood of a lower resistance value for the second surface layer 135. When the second surface layer 135 is plated, the thickness of the plating is, for example, about 2 to 10 μm, and the combined thickness of the second surface layer 135 and the plating is, for example, about 7 to 30 μm.

[0042] The portions of the first connection portion 132 that do not overlap with the second insulating substrate 12 and the portions of the second connection portion 134 that do not overlap with the second insulating substrate 12 may also be plated with gold plating and / or nickel plating.

[0043] As shown in Figures 1 to 5, the first surface layer 131 may be in contact with the third side surface 112 of the first insulating substrate 11. In this case, the first insulating substrate 11 may have a notch 114 cut out from the first upper surface 111 to the third side surface 112 at the connection point between the first surface layer 131 and the third side surface 112. The inner wall surface of the notch 114 may be covered with a metal film that connects to the first surface layer 131, and may be castellated. This makes it easier to improve the bonding strength between the first surface layer 131 and the external terminal 24 when an external terminal 24 such as a lead terminal is connected to the first surface layer 131 by forming a fillet of a bonding material such as metal brazing material.

[0044] In order not to reduce the current capacity of the first conductor 13 between the first insulating substrate 11 and the second insulating substrate 12, the first conductor 13 can also be formed in each of the forms shown in FIGS. 6 to 8. In FIGS. 6 to 8, the first conductor 13 is shown by a solid line, and the other parts are shown by a broken line. In the form shown in FIG. 6, the first conductor 13 has two layers, a layer extending from the third side surface 112 to the fourth side surface 113 on the first insulating substrate 11, and a layer extending from the third side surface 112 to the fourth side surface 113 inside the first insulating substrate 11. In the form shown in FIG. 7, the inner layer portion 133 of the first conductor 13 is divided into two layers. In the form shown in FIG. 8, the inner layer portion 133 of the first conductor 13 is divided into two layers, and these two layers are integrally connected by a long via.

[0045] The materials of the insulators such as the first insulating substrate 11, the second insulating substrate 12, and the insulating film 14 may be ceramic sintered bodies such as aluminum oxide sintered bodies, aluminum nitride sintered bodies, silicon carbide sintered bodies, mullite sintered bodies, and glass ceramics. Also, the materials of the insulators such as the first insulating substrate 11, the second insulating substrate 12, and the insulating film 14 may be resins such as epoxy resins, polyimides, and liquid crystal polymers. The materials of the first insulating substrate 11, the second insulating substrate 12, and the insulating film 14 may be the same as each other or different from each other.

[0046] The material of the first conductor 13 is, for example, a metal such as tungsten, molybdenum, manganese, copper, gold, silver, or an alloy thereof.

[0047] When the materials of insulators such as the first insulating substrate 11, the second insulating substrate 12, and the insulating film 14 are made of an aluminum oxide sintered body and a tungsten metallized layer is used as the first conductor 13, the wiring substrate 10 can be manufactured as follows, for example. First, the raw material powder of the insulator is kneaded with an organic solvent and an organic binder to obtain an insulating material slurry. The raw material powder of the insulator mainly consists of aluminum oxide powder and powder such as silicon oxide that becomes a sintering aid component. Next, the insulating material slurry is formed into a sheet shape by a forming method such as the doctor blade method or the lip coater method to form a ceramic green sheet. Also, for forming the first conductor 13, tungsten powder is mixed with an organic solvent and an organic binder to form a metal paste. The metal paste is appropriately printed at a predetermined position on the ceramic green sheet by a screen printing method or the like. At this time, in order to make the inner layer portion 133, the first connection portion 132, and the second connection portion 134 thick films, for example, these regions are metallized by overlapping them twice. Next, for forming the insulating film 14, the insulating material slurry is appropriately laminated at a predetermined position. If necessary, a plurality of ceramic green sheets are manufactured, and the manufactured ceramic green sheets are laminated to form a laminate. Then, this laminate is fired at a temperature of about 1300 to 1600 °C. A through hole may be provided at a predetermined position on the ceramic green sheet prior to printing the metal paste, and the same metal paste as described above is filled in this through hole and fired together with the ceramic green sheet to form a via conductor. Nickel plating of about 1 to 10 μm and gold plating of about 0.1 to 3 μm may be sequentially applied to the first surface layer portion 131, the second surface layer portion 135, the portion of the first connection portion 132 that does not overlap with the second insulating substrate 12, and the portion of the second connection portion 134 that does not overlap with the second insulating substrate 12.

[0048] [Package for housing electronic components] As shown in FIG. 9, the package for housing electronic components 20 may include a substrate 21, a frame body 22 located on the substrate 21, and a wiring substrate 10 joined to the frame body 22. In the package 20 for housing electronic components, the wiring substrate 10 can function as an input / output terminal. There may be a plurality of wiring substrates 10.

[0049] The substrate 21 is, for example, a rectangular plate-shaped member. The frame 22 is a frame-shaped member provided in a position that surrounds the mounting area of ​​the electronic component 31 in a plan view. The frame 22 may be integrally molded with the substrate 21, or it may be a separate component from the substrate 21.

[0050] The substrate 21 and the frame 22 can be configured, for example, by stacking multiple insulating substrates. As insulating substrates, for example, aluminum oxide sintered bodies, aluminum nitride sintered bodies, silicon carbide sintered bodies, mullite sintered bodies, glass ceramics, and other ceramic sintered bodies can be used. The materials of the substrate 21 and the frame 22 may be metals. Examples of metals include copper, tungsten, molybdenum, iron, nickel, or cobalt, or alloys thereof. Specific examples of alloys include copper-tungsten alloys, copper-molybdenum alloys, iron-nickel-cobalt alloys, and so on. The materials of the substrate 21 and the frame 22 may be the same or different.

[0051] The frame 22 may be integrally molded with the insulating substrates of the wiring board 10, such as the first insulating substrate 11 and the second insulating substrate 12, or it may be a separate component from the insulating substrates of the wiring board 10. If the insulating substrates of the wiring board 10 and the frame 22 are made of the same material, they are easier to integrally mold.

[0052] As shown in Figure 9, the electronic component housing package 20 may include a seal ring 23 located on the frame 22. The seal ring 23 can function as a sealing material when the electronic component housing package 20 is hermetically sealed using the lid 32 after the electronic component 31 has been mounted. The seal ring 23 may be formed, for example, by joining a frame-shaped metal plate containing an Fe-Ni alloy, Fe-Ni-Co alloy, etc., to a frame formed of a conductive paste containing a high-melting-point metal such as tungsten or molybdenum using brazing material or the like.

[0053] As shown in Figure 9, the electronic component housing package 20 may be equipped with external terminals 24. The external terminals 24 can be joined to the first surface layer 131 by a bonding material such as metal brazing material. In this case, if the bonding material forms a fillet inside the notch 114, the bonding strength is improved. Examples of external terminals 24 include lead terminals, bonding wires, and terminals of a printed circuit board (PCB). The printed circuit board (PCB) may be a flexible printed circuit board (FPC). When the external terminals 24 are joined to the first surface layer 131, the wiring board 10 may be arranged so that the first surface layer 131 faces outward from the electronic component housing package 20.

[0054] [Electronic Module] As shown in Figure 10, the electronic module 30 may include an electronic component housing package 20, an electronic component 31 located on a substrate 21 and electrically connected to the first conductor 13, and a lid 32 located on a frame 22.

[0055] The electronic component 31 may be located on a mounting member provided on the substrate 21. The electronic component 31 may be electrically connected to the first conductor 13 via a connecting member such as a bonding wire.

[0056] The electronic component 31 is a component that receives or outputs high-frequency signals related to optical communication (for example, signals with a frequency band of about 10 GHz or higher). Specific examples of the electronic component 31 include light-emitting elements, light-receiving elements, and power amplifiers.

[0057] The cover 32 is, for example, a plate-shaped member that can reduce the intrusion of foreign matter such as moisture and fine particles into the interior (cavity) of the electronic module 30. The cover 32 may be made of the same metal material as the seal ring 23, or it may be made from the same material as the substrate 21 and frame 22, processed and molded into a plate shape.

[0058] The following are further examples of embodiments of the wiring board and electronic component housing package relating to this disclosure.

[0059] (1) One embodiment of a wiring board according to the present disclosure comprises: a first insulating substrate having a first upper surface; a first conductor located on the first upper surface; and a second insulating substrate located on the first upper surface and the first conductor and extending intersecting the first conductor, wherein the first conductor has an inner layer located between the first insulating substrate and the second insulating substrate, and a first surface layer located without overlapping the second insulating substrate, and the thickness of the inner layer is greater than the thickness of the first surface layer.

[0060] (2) One embodiment of the wiring board according to the present disclosure is the wiring board according to (1) above, wherein the first conductor has a second surface layer that is located on the opposite side of the first surface layer with respect to the inner layer without overlapping with the second insulating substrate, and the thickness of the inner layer is greater than the thickness of the second surface layer.

[0061] (3) One embodiment of the wiring board according to the present disclosure is the wiring board according to (1) or (2) above, comprising an insulating film located on the first upper surface, wherein the second insulating substrate has a first side surface facing the side on which the first surface layer is located, and the insulating film has one or more first parts extending along the first side surface, and at least a portion of the first parts is located between the first upper surface and the first side surface without overlapping with the first conductor in a plan view.

[0062] (4) One embodiment of a wiring board according to the present disclosure is a wiring board according to (2) above or (3) referencing (2) above, comprising an insulating film located on the first upper surface, wherein the second insulating substrate has a first side surface facing the side on which the first surface layer is located and a second side surface facing the side on which the second surface layer is located, and the insulating film has one or more first parts extending along the first side surface and one or more second parts extending along the second side surface, wherein at least a portion of the first part and at least a portion of the second part are located between the first upper surface and the second insulating substrate.

[0063] (5) One embodiment of the wiring board according to the present disclosure is the wiring board described in (4) above, wherein the first part and the second part are not directly joined to each other.

[0064] (6) One embodiment of the wiring board according to the present disclosure is a wiring board according to any of (3) to (5) above, wherein at least a portion of the insulating film is located on the inner layer.

[0065] (7) One embodiment of the wiring board according to the present disclosure is a wiring board according to any of (1) to (6) above, wherein the width of the inner layer is smaller than the width of the first surface layer.

[0066] (8) One embodiment of the wiring board according to the present disclosure is a wiring board according to any of (1) to (7) above, wherein the first conductor has a first connection portion located between the inner layer and the first surface layer, at least a part of the first connection portion does not overlap with the second insulating substrate, and the thickness of the portion of the first connection portion that does not overlap with the second insulating substrate is greater than the thickness of the first surface layer.

[0067] (9) One embodiment of the wiring board according to the present disclosure is the wiring board according to (8) above, wherein the width of the inner layer is smaller than the width of the first surface layer, and the first connection portion has a tapered shape in which the width gradually decreases from the side of the first surface layer to the side of the inner layer.

[0068] (10) One embodiment of the wiring board according to the present disclosure is the wiring board according to (8) or (9) above, wherein the second insulating substrate has a first side surface facing the side on which the first surface layer is located, and the first connection portion is located overlapping with the first side surface in a plan view.

[0069] (11) One embodiment of a wiring board according to the present disclosure is a wiring board according to any of (8) to (10) above, comprising an insulating film located on the first upper surface, wherein the insulating film has one or more first parts extending along the first side surface, and at least a portion of the first parts is located on the first connection portion.

[0070] (12) One embodiment of the wiring board according to the present disclosure is a wiring board according to any of (1) to (11) above, wherein the thickness of the inner layer is 1.2 times or more the thickness of the first surface layer.

[0071] (13) One embodiment of the wiring board according to the present disclosure is a wiring board according to any of (1) to (12) above, wherein the thickness of the inner layer is twice or less the thickness of the first surface layer.

[0072] (14) One embodiment of the wiring board according to the present disclosure is a wiring board according to any of (1) to (13) above, wherein the thickness of the first surface layer is 20 μm or less.

[0073] (15) One embodiment of an electronic component storage package according to the present disclosure comprises a substrate, a frame located on the substrate, and any of the above wiring boards (1) to (14) joined to the frame.

[0074] Furthermore, details shown in the embodiments described above may be modified as appropriate without departing from the spirit of this disclosure. The scope of this disclosure includes the scope of the invention as described in the claims and its equivalents. Various combinations of each embodiment are not limited to the examples of embodiments described above. Combinations of each embodiment are also possible.

[0075] 10 Wiring board 11 First insulating substrate 111 First top surface 112 Third side surface 113 Fourth side surface 114 Notch 12 Second insulating substrate 121 First side surface 122 Second side surface 13 First conductor 131 First surface layer 132 First connection part 133 Inner layer 134 Second connection part 135 Second surface layer 14 Insulating film 141 First part 142 Second part 20 Package for housing electronic components 21 Substrate 22 Frame 23 Seal ring 24 External terminal 30 Electronic module 31 Electronic component 32 Cover

Claims

1. A wiring board comprising: a first insulating substrate having a first upper surface; a first conductor located on the first upper surface; and a second insulating substrate located on the first upper surface and the first conductor, and extending intersecting the first conductor, wherein the first conductor has an inner layer located between the first insulating substrate and the second insulating substrate, and a first surface layer located without overlapping the second insulating substrate, and the thickness of the inner layer is greater than the thickness of the first surface layer.

2. The wiring board according to claim 1, wherein the first conductor has a second surface layer located on the opposite side of the first surface layer, with the inner layer in between, without overlapping with the second insulating substrate, and the thickness of the inner layer is greater than the thickness of the second surface layer.

3. A wiring board according to claim 1 or 2, comprising an insulating film located on the first upper surface, wherein the second insulating substrate has a first side surface facing the side on which the first surface layer is located, the insulating film has one or more first parts extending along the first side surface, and at least a portion of the first parts is located between the first upper surface and the first side surface without overlapping with the first conductor in a plan view.

4. A wiring board according to claim 2, comprising an insulating film located on the first upper surface, wherein the second insulating substrate has a first side surface facing the side on which the first surface layer is located and a second side surface facing the side on which the second surface layer is located, the insulating film has one or more first parts extending along the first side surface and one or more second parts extending along the second side surface, and at least a portion of the first parts and at least a portion of the second parts are located between the first upper surface and the second insulating substrate.

5. The wiring board according to claim 4, wherein the first part and the second part are not directly joined to each other.

6. The wiring substrate according to any one of claims 3 to 5, wherein at least a portion of the insulating film is located on the inner layer.

7. The wiring board according to any one of claims 1 to 6, wherein the width of the inner layer is smaller than the width of the first surface layer.

8. The wiring board according to any one of claims 1 to 7, wherein the first conductor has a first connection portion located between the inner layer portion and the first surface layer portion, at least a part of the first connection portion does not overlap with the second insulating substrate, and the thickness of the portion of the first connection portion that does not overlap with the second insulating substrate is greater than the thickness of the first surface layer portion.

9. The wiring board according to claim 8, wherein the width of the inner layer is smaller than the width of the first surface layer, and the first connection portion has a tapered shape in which the width gradually decreases from the side of the first surface layer to the side of the inner layer.

10. The wiring board according to claim 8 or 9, wherein the second insulating substrate has a first side surface facing the side on which the first surface layer is located, and the first connecting portion is located overlapping with the first side surface in a plan view.

11. A wiring board according to any one of claims 8 to 10, comprising an insulating film located on the first upper surface, wherein the insulating film has one or more first parts extending along the first side surface, and at least a portion of the first parts is located on the first connection portion.

12. The wiring board according to any one of claims 1 to 11, wherein the thickness of the inner layer is 1.2 times or more the thickness of the first surface layer.

13. The wiring board according to any one of claims 1 to 12, wherein the thickness of the inner layer is twice or less the thickness of the first surface layer.

14. The wiring board according to any one of claims 1 to 13, wherein the thickness of the first surface layer is 20 μm or less.

15. An electronic component storage package comprising: a substrate; a frame positioned on the substrate; and a wiring board according to any one of claims 1 to 14 joined to the frame.

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