Wiring board

Abstract

A wiring board 1 is formed by laminating an insulation layer 10 and a thermal expansion adjustment layer 20 in which a thermal expansion adjustment part 21 including a thermal expansion adjustment material having a thermal expansion coefficient larger than that of the insulation layer 10 is arranged. The wiring board 1 includes a connection terminal 40 on a first principal surface 1a of the wiring board 1. At least one layer of the thermal expansion adjustment layer 20 is a first thermal expansion adjustment layer 120 in which an area S22 of the thermal expansion adjustment part 21 when viewed from a lamination direction is 20% to 80% of an area S10 based on an outer shape of the insulation layer 10 when viewed from the lamination direction.

Description

wiring board

[0001] The present invention relates to a wiring board.

[0002] 2. Description of the Related Art In wiring boards obtained by laminating insulating layers and wiring layers, it is known to combine base materials with different thermal expansion coefficients in order to prevent warping and peeling of the board.

[0003] For example, Patent Document 1 discloses that in a wiring board in which a resin insulating layer and a conductor layer are laminated on a core substrate, the linear expansion coefficient α of the core substrate is set to 3-30 ppm / °C, and the thermal expansion coefficient β of the resin insulating layer adjacent to the core substrate is set to 5-30 ppm / °C, so as to satisfy 0.5≦β / α≦1.5.

[0004] Patent Document 2 also discloses that in a fine-lined laminated sintered ceramic wiring board having a base material made of a plurality of dielectric layers including ceramic, and surface electrodes and inner wiring layers each containing a conductor, the thermal expansion coefficient of the ceramic constituting the dielectric layer in which the fine-lined conductors are embedded is configured to be smaller than the thermal expansion coefficient of the ceramic constituting the dielectric layer in which the fine-lined conductors are not embedded.

[0005] JP 2005-191307 A JP 2013-197440 A

[0006] The methods described in Patent Documents 1 and 2 are both intended to eliminate warping and peeling of the wiring board itself due to temperature changes. However, when the wiring boards described in Patent Documents 1 and 2 are mounted on another substrate for use, there is a problem in that stress applied to the connection portions (terminal portions and solder portions) increases due to the difference in thermal expansion coefficient between the mounting substrate and the substrate (hereinafter also referred to as the main substrate). In other words, when the thermal expansion coefficient of the main substrate is greater than that of the wiring board, the difference in the thermal expansion coefficients between the wiring board and the main substrate causes large stress to occur at the connection portion between the wiring board and the main substrate.

[0007] The present invention has been made to solve the above problems, and aims to provide a wiring board that is less likely to generate stress at the connection part when mounted on a main board that has a larger thermal expansion coefficient than the insulating layer that constitutes the wiring board, and that can suppress damage to the connection part.

[0008] The wiring board of the present invention is a wiring board formed by laminating an insulating layer and a thermal expansion adjustment layer in which a thermal expansion adjustment portion containing a thermal expansion adjustment material having a thermal expansion coefficient larger than that of the insulating layer is arranged, and is characterized in that it has a connection terminal on a first main surface of the wiring board, and at least one layer of the thermal expansion adjustment layer is a first thermal expansion adjustment layer in which the area of ​​the thermal expansion adjustment portion when viewed from the stacking direction is 20% or more and 80% or less of the area based on the external shape of the insulating layer when viewed from the stacking direction.

[0009] According to the present invention, a wiring board can be provided that is less likely to generate stress at the connection part when mounted on a main board having a thermal expansion coefficient greater than that of the insulating layer that constitutes the wiring board, and that can suppress damage to the connection part.

[0010] FIG. 1 is a cross-sectional view schematically illustrating an example of a wiring board. FIG. 2A is a diagram in which the cross-sectional view of line A-A and the cross-sectional view of line B-B of the wiring board shown in FIG. 1 are overlapped. FIG. 2B is a diagram schematically illustrating the area of ​​a thermal expansion adjustment portion in the thermal expansion adjustment layer shown in FIG. 2A. FIG. 2C is a diagram schematically illustrating the area of ​​a non-placement portion in the thermal expansion adjustment layer shown in FIG. 2A. FIG. 2D is a diagram schematically illustrating the area based on the outer shape of the insulating layer shown in FIG. 2A. FIG. 3 is a diagram schematically illustrating a comparison between the positions of connection terminals and the positions of the thermal expansion adjustment portions of the first thermal expansion adjustment layer when the wiring board shown in FIG. 1 is viewed from the stacking direction. FIG. 4 is a diagram schematically illustrating a comparison between the positions of connection terminals and the positions of the thermal expansion adjustment portions of the first thermal expansion adjustment layer when another example of a wiring board is viewed from the stacking direction. Fig. 5 is a diagram schematically illustrating a comparison between the positions of the connection terminals and the thermal expansion adjustment portion of the first thermal expansion adjustment layer when viewed from the stacking direction of yet another example of a wiring board. Fig. 6 is a diagram schematically illustrating a comparison between the positions of the connection terminals and the thermal expansion adjustment portion of the first thermal expansion adjustment layer when viewed from the stacking direction of yet another example of a wiring board. Fig. 7 is a diagram schematically illustrating a comparison between the positions of the connection terminals and the thermal expansion adjustment portion of the first thermal expansion adjustment layer when viewed from the stacking direction of yet another example of a wiring board. Fig. 8 is a diagram schematically illustrating a comparison between the positions of the connection terminals and the thermal expansion adjustment portion of the first thermal expansion adjustment layer when viewed from the stacking direction of yet another example of a wiring board. Fig. 9 is a diagram schematically illustrating a comparison between the positions of the connection terminals and the thermal expansion adjustment portion of the first thermal expansion adjustment layer when viewed from the stacking direction of yet another example of a wiring board. Fig. 10 is a diagram schematically showing a comparison between the positions of the connection terminals and the positions of the thermal expansion adjustment portions of the first thermal expansion adjustment layer when viewing yet another example of a wiring board from the stacking direction. Fig. 11 is a cross-sectional view schematically showing yet another example of a wiring board of the present invention. Fig. 12 is a cross-sectional view schematically showing yet another example of a wiring board of the present invention. Fig. 13 is a cross-sectional view schematically showing yet another example of a wiring board of the present invention.

[0011] The wiring board of the present invention will be described below. Note that the present invention is not limited to the following configurations and may be modified as appropriate within the scope of the present invention. In addition, a combination of multiple individual preferred configurations described below also constitutes the present invention.

[0012] The drawings shown below are schematic diagrams, and the dimensions, aspect ratio, and other scales may differ from those of the actual product. In the drawings, the same or equivalent parts will be designated by the same reference numerals. In addition, the same elements will be designated by the same reference numerals in each drawing, and duplicate explanations will be omitted.

[0013] In this specification, terms indicating the relationship between elements (e.g., "opposite," "orthogonal," etc.) and terms indicating the shape of elements not only mean the literal and strict form, but also mean a range that is substantially equivalent, for example, a range that includes a difference of about a few percent.

[0014] The following embodiments are merely examples, and it goes without saying that partial substitution or combination of the configurations shown in different embodiments is possible. In the description of each embodiment, descriptions of matters common to the previously described embodiments will be omitted, and only differences will be described. In particular, similar effects resulting from similar configurations will not be mentioned in each embodiment.

[0015] [Wiring Board] The wiring board of the present invention is a wiring board formed by laminating an insulating layer and a thermal expansion adjustment layer in which a thermal expansion adjustment portion containing a thermal expansion adjustment material having a thermal expansion coefficient larger than that of the insulating layer is arranged, and is characterized in that it has a connection terminal on a first main surface of the wiring board, and at least one layer of the thermal expansion adjustment layer is a first thermal expansion adjustment layer in which the area of ​​the thermal expansion adjustment portion when viewed from the stacking direction is 20% or more and 80% or less of the area based on the external shape of the insulating layer when viewed from the stacking direction.

[0016] FIG. 1 is a cross-sectional view schematically illustrating an example of a wiring board. The wiring board 1 shown in FIG. 1 is formed by laminating an insulating layer 10 and a thermal expansion adjustment layer 20. The insulating layer 10 is primarily made of an insulating material. The thermal expansion adjustment layer 20 is a layer in which a thermal expansion adjustment portion 21 is arranged, the thermal expansion adjustment portion 21 containing a thermal expansion adjustment material having a thermal expansion coefficient (hereinafter simply referred to as the thermal expansion coefficient) in the horizontal direction (the XY plane direction in FIG. 1 ) greater than that of the insulating layer. The portion of the thermal expansion adjustment layer 20 in which the thermal expansion adjustment portion 21 is arranged is also referred to as an arrangement portion 22, and the portion in which the thermal expansion adjustment portion 21 is not arranged is also referred to as an absence portion 29.

[0017] Since the thermal expansion coefficient is a value specific to a substance, the thermal expansion coefficient can be determined by determining the composition (including the crystal structure) of the insulating layer and the thermal expansion adjusting material by elemental analysis or the like and comparing it with a database.

[0018] The thermal expansion coefficient of the thermal expansion adjusting material is 10 × 10 －６ [K －１ ] or more, 20 x 10 －６ [K －１ ] or less.

[0019] The wiring board 1 has a first main surface 1a and a second main surface 1b that face each other in the stacking direction (the direction indicated by the arrow Z in FIG. 1), a first side surface 1c and a second side surface 1d that face each other in the length direction (the direction indicated by the arrow X in FIG. 1) that is perpendicular to the stacking direction, and a third side surface and a fourth side surface (the side surfaces indicated by the reference symbols 1e and 1f in FIG. 3) that face each other in the width direction (the direction indicated by the arrow Y in FIG. 1) that is perpendicular to the stacking direction and the length direction.

[0020] The first main surface 1a of the wiring board 1 is provided with connection terminals 40. The connection terminals 40 are terminals used to mount the wiring board 1 on another substrate, and are electrically connected to the internal wiring (thermal expansion adjusting portions 21) within the wiring board 1 through the via conductors 11. Therefore, the first main surface 1a serves as a mounting surface.

[0021] Terminals 30 may be exposed on the second main surface 1b of the wiring board 1. The terminals 30 are used when mounting electronic components on the second main surface 1b of the wiring board 1. When the terminals 30 are made of a thermal expansion adjusting material, the terminals 30 also correspond to the thermal expansion adjusting portions 21.

[0022] In the wiring board 1, one of the thermal expansion adjustment layers 20 is a first thermal expansion adjustment layer 120. The first thermal expansion adjustment layer 120 is disposed between a first insulating layer 101, which is the first insulating layer 10 counting from the first main surface 1a of the wiring board 1, and a second insulating layer 102, which is the second insulating layer 10.

[0023] The first thermal expansion adjustment layer 120 is a layer of the thermal expansion adjustment layer 20 in which the area of ​​the thermal expansion adjustment section 21 when viewed from the stacking direction (equal to the area of ​​the placement section 22) is 20% or more and 80% or less of the area based on the external shape of the insulating layer 10 when viewed from the stacking direction (hereinafter simply referred to as the area of ​​the insulating layer).

[0024] 2A is a diagram in which the cross-sectional view of line A-A and the cross-sectional view of line B-B of the wiring board shown in FIG. 1 are superimposed. The thermal expansion adjustment layer 20 has an arrangement portion 22 in which a thermal expansion adjustment portion made of a thermal expansion adjustment material is arranged, and an absence portion 29 in which no thermal expansion adjustment portion is arranged. The insulating layer 10 is provided with via conductors 11 that connect the connection terminals 40 to the wiring (thermal expansion adjustment portion) inside the substrate. In the stacking direction, the region in which the thermal expansion adjustment portion is arranged overlaps the region in which the via conductors 11 are provided. Therefore, the thermal expansion adjustment portion is electrically connected to the via conductors 11.

[0025] 2B is a diagram schematically illustrating the area of ​​the thermal expansion adjusting portion in the thermal expansion adjusting layer shown in FIG. 2A. As shown in FIG. 2B, the area of ​​the arrangement portion 22 where the thermal expansion adjusting portion is arranged (the area indicated by diagonal lines in FIG. 2B) is S ２２ The area is given by

[0026] 2C is a diagram schematically illustrating the area of ​​a non-placement portion in the thermal expansion adjustment layer illustrated in FIG. 2A. As illustrated in FIG. 2C, the area of ​​a non-placement portion 29 where a thermal expansion adjustment portion is not placed (the area indicated by diagonal lines in FIG. 2C) is S ２９ The area is given by

[0027] 2D is a diagram schematically illustrating the area based on the outer shape of the insulating layer shown in FIG. 2A. As shown in FIG. 2D, the area S based on the outer shape of the insulating layer 10 (hereinafter also simply referred to as the area of ​​the insulating layer) １０is determined based on the outer shape of the insulating layer. Therefore, the area of ​​the portion other than the insulating material provided in the insulating layer 10, for example, the area of ​​the via conductor 11, is determined based on the outer shape of the insulating layer 10. １０ Included.

[0028] As shown in FIGS. 1 and 2A, the dimensions of the insulating layer 10 and the thermal expansion adjusting layer 20 are the same when viewed in the stacking direction. １０ is the area S of the placement section 22 ２２ and the area S of the non-placement portion 29 ２９ is equal to the sum of (S １０ = S ２２ +S ２９ ).

[0029] The thermal expansion adjustment layer in which the area of ​​the thermal expansion adjustment portion (area of ​​the arrangement portion) is 20% to 80% of the area based on the outer shape of the insulating layer is the first thermal expansion adjustment layer.

[0030] The thermal expansion adjusting layer 20 shown in FIG. 2A has an area S １０ The area S of the arrangement portion 22 ２２ The proportion of ２２ = 0.215 × S １０ ) and therefore corresponds to the first thermal expansion adjustment layer 120.

[0031] The thermal expansion adjustment portion includes a thermal expansion adjusting material having a thermal expansion coefficient greater than that of the insulating layer. When viewed from the stacking direction, the first thermal expansion adjustment layer, in which the thermal expansion adjustment portion is arranged at an area ratio of 20% to 80% inclusive, can be said to have a thermal expansion coefficient greater than that of the insulating layer. By increasing the thermal expansion coefficient of the wiring board with the first thermal expansion adjustment layer, stress is less likely to occur in the connection portion when the wiring board is mounted on a main board having a thermal expansion coefficient greater than that of the insulating layer that constitutes the wiring board, and damage to the connection portion can be suppressed.

[0032] In this specification, a thermal expansion adjustment layer whose area of ​​the thermal expansion adjustment portion when viewed from the stacking direction is less than 20% of the area of ​​the insulating layer is referred to as a second thermal expansion adjustment layer, and a thermal expansion adjustment layer whose area is more than 80% is referred to as a third thermal expansion adjustment layer.

[0033] In the wiring board of the present invention, as long as at least one of the thermal expansion adjustment layers is a first thermal expansion adjustment layer, the wiring board may also include a second thermal expansion adjustment layer and a third thermal expansion adjustment layer.

[0034] Examples of insulating materials that form the insulating layer include low-temperature co-fired ceramic (LTCC) materials and resin materials. A wiring board whose insulating layer is made of an LTCC material is also called an LTCC substrate. A wiring board whose insulating layer is made of a resin material is also called a printed circuit board.

[0035] Low-temperature co-fired ceramic materials are ceramic materials that can be fired at temperatures of 1000°C or less and can be co-fired with Au, Ag, Cu, etc., which have low resistivity. Specific examples of low-temperature co-fired ceramic materials include glass composite low-temperature co-fired ceramic materials obtained by mixing ceramic powders such as alumina, zirconia, magnesia, and forsterite with borosilicate glass; ZnO-MgO-Al ２ O ３ -SiO ２ Glass-ceramic low-temperature fired ceramic material using BaO-Al ２ O ３ -SiO ２ ceramic powder and Al ２ O ３ -CaO-SiO ２ -MgO-B ２ O ３ Examples of suitable ceramic materials include non-glass-based low-temperature fired ceramic materials using ceramic powders.

[0036] The thermal expansion coefficient of the insulating layer made of low-temperature co-fired ceramic material is, for example, 5×10 －６ [K －１ ] or more, 18 x 10 －６ [K －１ ] is as follows.

[0037] Examples of resin materials constituting the insulating layer include epoxy resins. The insulating layer may contain a filler such as glass fiber in addition to the resin material. When the insulating layer contains a filler in addition to the resin material, the mechanical properties are improved and the thermal expansion coefficient may be reduced compared to before the filler is added.

[0038] The thermal expansion coefficient of the insulating layer made of a resin material is, for example, 9×10 －６ [K －１ ] or more, 22 x 10 －６ [K －１ ]or less.

[0039] The insulating layer may also contain a thermal expansion adjusting material, but it is preferable that the thermal expansion adjusting material in the insulating layer functions as a conductor (via conductor) that penetrates the insulating layer in the thickness direction and connects, in the stacking direction, thermal expansion adjusting portions provided on two thermal expansion adjusting layers that face each other across the insulating layer.

[0040] The thermal expansion adjuster is preferably a conductive material. The conductive material is preferably one that can be co-fired with the low-temperature co-fired ceramic material, and examples thereof include at least one metal selected from the group consisting of Cu, Ag, Au, and alloys thereof. When the thermal expansion adjuster is the above metal, at least a portion of the thermal expansion adjuster can be used as internal wiring. In terms of the manufacturing process, the thermal expansion adjuster can be formed simultaneously with the internal wiring, so the manufacturing process is not complicated. Additionally, the above metals have good electrical conductivity and large thermal expansion coefficients, making them suitable as thermal expansion adjusters.

[0041] A plurality of thermal expansion adjusting portions may be present in one thermal expansion adjusting layer. In this case, the total area of ​​the thermal expansion adjusting portions as viewed from the stacking direction is regarded as the area of ​​the thermal expansion adjusting portion.

[0042] The thermal expansion adjusting portion may contain two or more types of thermal expansion adjusting materials having different thermal expansion coefficients.

[0043] Thermal expansion adjustment portions can be divided into several types depending on the function they perform within the wiring board. Specifically, thermal expansion adjustment portions include a thermal expansion adjustment portion (signal portion) that functions as a signal wiring, a thermal expansion adjustment portion (GND portion) that functions as a GND wiring, and a thermal expansion adjustment portion (dummy portion) that functions as a dummy wiring. Whether a thermal expansion adjustment portion is a signal wiring (signal portion), a GND wiring (GND portion), or a dummy wiring (dummy portion) can be distinguished based on what the thermal expansion adjustment portion is connected to. Specifically, a thermal expansion adjustment portion that is connected to a GND terminal or a shield is a GND wiring. A thermal expansion adjustment portion that is not connected to anything is a dummy wiring. A thermal expansion adjustment portion other than a GND wiring or a dummy wiring is a signal wiring.

[0044] At least a part of the thermal expansion adjusting portion of the first thermal expansion adjusting layer is preferably GND wiring (GND portion). When at least a part of the thermal expansion adjusting portion of the first thermal expansion adjusting layer is GND wiring (GND portion), at least a part of the first thermal expansion adjusting layer functions as a shield, so that after the wiring board is mounted on the main board, interference between the signal lines and electronic components of the wiring board and the wiring and electronic components of the mounted main board can be prevented.

[0045] It is preferable that 80% or more of the area of ​​the thermal expansion adjustment portion included in the first thermal expansion adjustment layer is the thermal expansion adjustment portion serving as the GND wiring (GND portion).

[0046] In the first thermal expansion adjustment portion, it is preferable that the total area of ​​the thermal expansion adjustment portion as GND wiring and the thermal expansion adjustment portion as dummy wiring be 20% or more and 80% or less of the area of ​​the insulating layer, and it is preferable that the area of ​​the thermal expansion adjustment portion as GND wiring be 20% or more and 80% or less of the area of ​​the insulating layer.

[0047] The wiring board of the present invention may include a shielding film. The shielding film is preferably provided on a surface other than the mounting surface of the wiring board. For example, when the mounting surface is the first main surface, the shielding film is preferably provided on at least one of the first side surface, the second side surface, the third side surface, the fourth side surface, and the second main surface, more preferably on two or more surfaces, and particularly preferably on all of the first side surface, the second side surface, the third side surface, the fourth side surface, and the second main surface. The shielding film prevents electromagnetic interference between the inside and outside of the wiring board. The thermal expansion adjusting portion serving as the GND wiring is preferably connected directly or indirectly to the shielding film.

[0048] The position where the first thermal expansion adjustment layer is disposed is not particularly limited, but it is preferable that it be close to the connection terminal where stress is concentrated. Specifically, it is preferable that the first thermal expansion adjustment layer be disposed between the first insulating layer, which is the first insulating layer counting from the first main surface of the wiring board, and the second insulating layer, which is the second insulating layer. If the first thermal expansion adjustment layer is disposed between the first insulating layer, which is the first insulating layer counting from the first main surface of the wiring board, and the second insulating layer, which is the second insulating layer, the thermal expansion coefficient becomes larger at a position close to the connection portion, and therefore the stress applied to the connection portion due to the difference in thermal expansion coefficient with the main substrate can be further reduced.

[0049] In the wiring board 1 shown in Figure 1, the first thermal expansion adjustment layer 120 is arranged between the first insulating layer 101, which is the first insulating layer 10 counting from the first main surface of the wiring board, and the second insulating layer 102, which is the second insulating layer 10.

[0050] Two or more of the thermal expansion adjusting layers may be the first thermal expansion adjusting layer. For example, in addition to being provided between the first insulating layer and the second insulating layer, a first thermal expansion adjusting layer may also be provided between the second insulating layer and the third insulating layer (the third insulating layer counting from the first main surface of the wiring substrate).

[0051] The thermal expansion adjusting portions provided on the first thermal expansion adjusting layers may have different shapes.

[0052] In the wiring board of the present invention, the shape of the thermal expansion adjusting portion of the first thermal expansion adjusting layer when viewed from the stacking direction is not particularly limited and can take various shapes. Examples of the shape of the thermal expansion adjusting portion of the first thermal expansion adjusting layer will be described with reference to Figures 3, 4, 5, 6, 7, 8, 9, and 10.

[0053] Fig. 3 is a diagram schematically illustrating a comparison between the positions of the connection terminals and the positions of the thermal expansion adjustment portions of the first thermal expansion adjustment layer when the wiring board shown in Fig. 1 is viewed from the stacking direction. That is, Fig. 3 shows the positional relationship between the arrangement portion 22 and non-arrangement portion 29 in the first thermal expansion adjustment layer 120 constituting the wiring board 1 and the connection terminals 40 when viewed from the stacking direction. In Fig. 3, the location where the arrangement portion 22 where the thermal expansion adjustment portion is arranged and the connection terminal 40 overlap is also the location where the two overlap when the wiring board 1 is viewed transparently from the stacking direction.

[0054] 3 also shows the external shape of the wiring board 1. The external shape of the wiring board 1 seen from the stacking direction is a square with four sides (1c, 1d, 1e, 1f) of equal length. As explained in FIGS. 2A to 2D, the area (S ２２ ) of the insulating layer area (S １０ ) is 21.5%.

[0055] There are a total of 16 connection terminals 40, which are divided into connection terminals 40a and 40b arranged on the outermost periphery and connection terminals 40c not arranged on the outermost periphery according to their positions. The connection terminals 40a and 40b arranged on the outermost periphery are further divided into connection terminals 40a arranged on the outermost corners and connection terminals 40b arranged on the outermost sides.

[0056] When viewed from the stacking direction as shown in Figure 3, the thermal expansion adjustment portion (arrangement portion 22) of the first thermal expansion adjustment layer 120 overlaps with at least a portion of the connection terminal 40. More specifically, it overlaps with the connection terminal 40c that is not arranged on the outermost periphery of the connection terminals 40. When the thermal expansion adjustment portion of the first thermal expansion adjustment layer overlaps with at least a portion of the connection terminal when viewed from the stacking direction, it is possible to suppress the concentration of stress around the connection terminal, where stress is likely to concentrate. Note that "at least a portion of the connection terminal" refers to at least a portion of a single connection terminal when viewed from the stacking direction.

[0057] 4 is a diagram schematically illustrating a comparison between the positions of the connection terminals and the positions of the thermal expansion adjustment portions of the first thermal expansion adjustment layer when another example of a wiring board is viewed from the stacking direction. That is, FIG. 4 shows the positional relationship between the placement portion 22 and non-placement portion 29 in the first thermal expansion adjustment layer 120 constituting the wiring board 2 and the connection terminal 40 when viewed from the stacking direction. In FIG. 4, the location where the placement portion 22 where the thermal expansion adjustment portion is located and the connection terminal 40 overlap is also the location where the two overlap when the wiring board 2 is viewed transparently from the stacking direction.

[0058] Fig. 4 also shows the external shape of the wiring board 2. The wiring board 2 shown in Fig. 4 is different from the wiring board 1 shown in Fig. 3 only in the position of the thermal expansion adjustment portion of the first thermal expansion adjustment layer 120. Therefore, in the wiring board 2 shown in Fig. 4 as well, the ratio of the area of ​​the thermal expansion adjustment portion to the area of ​​the insulating layer 10 is 21.5%.

[0059] As shown in FIG. 4 , when viewed from the stacking direction, the thermal expansion adjustment portion (arrangement portion 22) of the first thermal expansion adjustment layer 120 overlaps with the connection terminal 40b of the connection terminals 40 that are arranged on the outermost edge. Because stress tends to concentrate on the connection terminals arranged on the outermost periphery of the wiring substrate, if the thermal expansion adjustment portion of the first thermal expansion adjustment layer overlaps with the connection terminals arranged on the outermost periphery of the wiring substrate when viewed from the stacking direction, stress concentration can be further suppressed. In the above case, it is sufficient that the thermal expansion adjustment portion of the first thermal expansion adjustment layer overlaps with at least one of the connection terminals arranged on the outermost periphery of the wiring substrate. Furthermore, the thermal expansion adjustment portion of the first thermal expansion adjustment layer may overlap only a portion or the entirety of a single connection terminal arranged on the outermost periphery of the wiring substrate.

[0060] 5 is a diagram schematically illustrating a comparison between the positions of the connection terminals and the positions of the thermal expansion adjustment portions of the first thermal expansion adjustment layer when viewing yet another example of a wiring board from the stacking direction. That is, Fig. 5 shows the positional relationship between the placement portion 22 and non-placement portion 29 in the first thermal expansion adjustment layer 120 constituting the wiring board 3 and the connection terminal 40 when viewed from the stacking direction. In Fig. 5, the location where the placement portion 22 where the thermal expansion adjustment portion is located and the connection terminal 40 overlap is also the location where the two overlap when viewing the wiring board 3 from the stacking direction.

[0061] 5 also shows the external shape of the wiring board 3. When viewed from the stacking direction, the external shape of the wiring board 3 is a square with four sides (3c, 3d, 3e, 3f) of equal length. The length of the two sides (3c and 3d) facing each other in the length direction (X direction) is also the dimension (width dimension) W of the wiring board 3 (insulating layer 10) in the width direction perpendicular to the length direction. The length of the two sides (3e and 3f) facing each other in the width direction (Y direction) is also the dimension (length dimension) L of the wiring board 3 (insulating layer 10) in the length direction perpendicular to the width direction.

[0062] In the wiring board 3 shown in FIG. 5 , the width Wy of the placement portion 22 of the first thermal expansion adjustment layer 120 as viewed from the stacking direction is at least half (58.3%) of the width W of the insulating layer 10, and the length Lx of the placement portion 22 is at least half (61.7%) of the length L of the insulating layer 10. When the width and length of the placement portion 22 of the first thermal expansion adjustment layer as viewed from the stacking direction are at least half the width and length of the insulating layer, respectively, the area of ​​the placement portion of the first thermal expansion adjustment layer is at least 25% of the area of ​​the insulating layer (35.0% in the wiring board 3 shown in FIG. 5 ), further reducing the difference in thermal expansion coefficient between the wiring board and the main board. Note that if the first thermal expansion adjustment layer has multiple placement portions, the above dimensions are not the sum of the dimensions of the multiple placement portions, but are calculated from the individual shapes of each placement portion. Therefore, for at least one of the multiple placement portions, if the width dimension Wy is equal to or greater than 1 / 2 of the width dimension W of the insulating layer and the length dimension Lx is equal to or greater than 1 / 2 of the length dimension L of the insulating layer, then it can be said that the external dimensions of the thermal expansion adjustment portion of the first thermal expansion adjustment layer are such that the width dimension is equal to or greater than 1 / 2 of the width dimension of the wiring board and the length dimension is equal to or greater than 1 / 2 of the length dimension of the wiring board.

[0063] 6 is a diagram schematically illustrating a comparison between the positions of the connection terminals and the positions of the thermal expansion adjustment portions of the first thermal expansion adjustment layer when viewing yet another example of a wiring board from the stacking direction. That is, Fig. 6 shows the positional relationship between the placement portion 22 and non-placement portion 29 in the first thermal expansion adjustment layer 120 constituting the wiring board 4, and the connection terminal 40 when viewed from the stacking direction. In Fig. 6, the location where the placement portion 22 where the thermal expansion adjustment portion is located and the connection terminal 40 overlap is also the location where the two overlap when viewing the wiring board 4 from the stacking direction.

[0064] 6 also shows the external shape of the wiring board 4. When viewed from the stacking direction, the external shape of the wiring board 4 is a rectangle in plan view, with the length dimension being greater than the width dimension. In this case, the sides 4e and 4f facing in the width direction of the wiring board 4 (the direction indicated by the arrow Y in FIG. 6) are the long sides, and the sides 4c and 4d facing in the length direction (the direction indicated by the arrow X in FIG. 6) are the short sides.

[0065] In the wiring board 4 shown in FIG. 6, the ratio of the area of ​​the thermal expansion adjusting portion of the first thermal expansion adjusting layer 120 (the area of ​​the arrangement portion 22) to the area of ​​the insulating layer 10 is 20.7%.

[0066] The 16 connection terminals provided on the wiring board 4 are divided into connection terminals 40a, 40d, and 40e arranged on the outermost periphery and connection terminals 40c that are not arranged on the outermost periphery, depending on their positions. The connection terminals 40a, 40d, and 40e arranged on the outermost periphery are further divided into connection terminals 40a arranged on the outermost corners, connection terminals 40d arranged on the outermost short sides 4c and 4d, and connection terminals 40e arranged on the outermost long sides 4e and 4f. The connection terminals 40a arranged on the outermost corners are also connection terminals arranged on both the outermost short sides and both sides.

[0067] In the wiring board 4 shown in Figure 6, the thermal expansion adjustment portion (arrangement portion 22) in the first thermal expansion adjustment layer 120 overlaps both the connection terminal 40d adjacent to one short side 4c of the periphery and the connection terminal 40d adjacent to the other short side 4d. If the external shape of the wiring board when viewed from above is rectangular as shown in Figure 6, the deformation (displacement) in the length direction will be greater than the deformation (displacement) in the width direction. In contrast, if the thermal expansion adjustment portion (arrangement portion) of the first thermal expansion adjustment layer is arranged so as to overlap both the connection terminal adjacent to one short side and the connection terminal adjacent to the other short side, the thermal expansion adjustment portion will be arranged along the length direction of the wiring board, thereby effectively suppressing deformation in the length direction.

[0068] In other words, when the external shape of the wiring board when viewed from above is an approximately rectangular shape having short sides and long sides, it is preferable that, when viewed from the stacking direction, the thermal expansion adjustment portion of the first thermal expansion adjustment layer is arranged so that it overlaps both the connection terminal adjacent to one short side and the connection terminal adjacent to the other short side of the multiple connection terminals.

[0069] When the thermal expansion adjustment portion in the first thermal expansion adjustment layer is arranged so as to overlap both the connection terminal adjacent to one short side of the outer periphery and the connection terminal adjacent to the other short side, the shape of the thermal expansion adjustment portion in the portion connecting the thermal expansion adjustment portion overlapping the connection terminal adjacent to one short side and the thermal expansion adjustment portion overlapping the connection terminal adjacent to the other short side is not particularly limited.

[0070] For example, another thermal expansion adjustment portion (third portion) may be provided so as to linearly connect a thermal expansion adjustment portion (first portion) overlapping a connection terminal adjacent to one short side and a thermal expansion adjustment portion (second portion) overlapping a connection terminal adjacent to the other short side, or another thermal expansion adjustment portion (third portion) may be provided so as to bend midway. In the wiring board 4 shown in Figure 6, another thermal expansion adjustment portion (third portion) is provided so as to bend midway between a thermal expansion adjustment portion (first portion) overlapping a connection terminal adjacent to one short side and a thermal expansion adjustment portion (second portion) overlapping a connection terminal adjacent to the other short side.

[0071] A thermal expansion adjustment portion that is arranged within the first thermal expansion adjustment layer and overlaps both the connection terminal adjacent to one short side of the outer periphery and the connection terminal adjacent to the other short side, such as the thermal expansion adjustment portion that constitutes the placement portion 22 shown in Figure 6, is also called a bridge-type thermal expansion adjustment portion because it has a shape that bridges from one short side to the other short side.

[0072] The area of ​​the bridge-type thermal expansion adjusting portion is preferably 20% or more and 80% or less of the area of ​​the insulating layer.

[0073] The bridge-type thermal expansion adjusting portion may overlap two or more of the connection terminals adjacent to one short side of the outer periphery, or may overlap two or more of the connection terminals adjacent to the other short side of the outer periphery.

[0074] The bridge-type thermal expansion adjusting portion is preferably a GND wiring.

[0075] The maximum dimension of the bridge-type thermal expansion adjusting portion in the width direction of the laminated substrate is preferably 10% or more and 50% or less of the width dimension of the laminated substrate.

[0076] The maximum dimension of the bridge-type thermal expansion adjusting portion in the length direction of the laminated substrate is preferably 80% or more and 95% or less of the length dimension of the laminated substrate.

[0077] The bridge-type thermal expansion adjustment portion may have a non-placement portion therein where no thermal expansion adjustment portion is placed. Furthermore, a thermal expansion adjustment portion may be placed inside the non-placement portion. In this case, the shape of the thermal expansion adjustment material is an example of a bridge-type thermal expansion adjustment portion obtained by modifying the shape of the second placement portion in the first thermal expansion adjustment layer described later with reference to FIG. 8 .

[0078] When viewed from the stacking direction, the length of the short side of the wiring board is preferably 50% or more and 100% or less of the length of the long side.

[0079] 7 is a diagram showing a comparison of the positions of the connection terminals and the thermal expansion adjustment portions of the first thermal expansion adjustment layer when viewing another example of a wiring board from the stacking direction. The wiring board 4′ shown in FIG. 7 is different from the wiring board 4 shown in FIG. 6 in the shape and number of the connection terminals and the shape of the arrangement portion in the first thermal expansion adjustment layer.

[0080] The 14 connection terminals provided on the wiring board 4' are divided into connection terminals 40a arranged at the outermost corners, connection terminals 40d arranged on the outermost short sides 4c and 4d, connection terminals 40e arranged on the outermost long sides 4e and 4f, and connection terminals 40c not arranged on the outermost sides.

[0081] 7, the first thermal expansion adjustment layer 120 has two arrangement portions 22 (221, 222) that are not in contact with each other and a non-arrangement portion 29. The arrangement portion 221 is arranged so as to overlap a portion of the connection terminal 40a arranged at the outermost corner. The arrangement portion 222 overlaps both the connection terminal 40e adjacent to one long side 4e of the periphery and the connection terminal 40e adjacent to the other long side 4f. At the same time, the arrangement portion 222 overlaps both the connection terminal 40d adjacent to one short side 4c of the periphery and the connection terminal 40a adjacent to the other short side 4d.

[0082] 7, the first thermal expansion adjustment layer 120 may have two or more arrangement portions 22 that overlap with the connection terminals 40. Furthermore, the arrangement portion 222 may be arranged so as to overlap across both the connection terminal 40 adjacent to one long side and the connection terminal 40 adjacent to the other long side.

[0083] In this specification, in the case of a non-rectangular arrangement portion such as the arrangement portion 222 shown in Fig. 7, the length dimension and width dimension refer to the maximum dimension in the corresponding direction. That is, the length dimension of the arrangement portion 222 shown in Fig. 7 is the length indicated by the double-headed arrow Lx, and the width dimension is the length indicated by the double-headed arrow Wy.

[0084] In this specification, the thermal expansion adjusting portion can be divided into several types depending on its purpose and shape. For example, the thermal expansion adjusting portion can be divided into a solid arrangement portion in which the thermal expansion adjusting portion is arranged in a solid pattern, an island arrangement portion in which the thermal expansion adjusting portion is arranged in an island pattern, and a linear arrangement portion in which the thermal expansion adjusting portion is arranged in a line.

[0085] A solid arrangement portion is an arrangement portion in which the thermal expansion adjustment portion is arranged so as to fill (fill in) the entire specific area. An island-shaped arrangement portion is an arrangement portion that is provided for the purpose of connecting the thermal expansion adjustment layer to a via conductor provided in an adjacent insulating layer, and has a circular, elliptical, or polygonal shape in a plan view that is slightly larger than the via conductor. Due to this purpose, the island-shaped arrangement portion is also called a via conductor connection portion. A linear arrangement portion is a linear (line-shaped) arrangement portion that is provided for the purpose of forming a conductive path in the thermal expansion adjustment layer. A portion of the thermal expansion adjustment layer where no thermal expansion adjustment portion is provided is also called a non-arrangement portion.

[0086] The arrangement portion may have only a solid arrangement portion, or may have an island arrangement portion or a linear arrangement portion in addition to a solid arrangement portion. The solid arrangement portion, the island arrangement portion, and the linear arrangement portion may be in contact with each other or may be separated from each other by a non-arrangement portion.

[0087] For example, the first thermal expansion adjustment layer may have a non-positioned portion where no thermal expansion adjustment portion is placed, a solid-positioned portion where the thermal expansion adjustment portion is placed in a solid pattern, and an island-shaped portion where the thermal expansion adjustment portion is placed in an island-shaped pattern.

[0088] In this case, it is preferable that in the first thermal expansion adjustment layer, the island-shaped arrangement portion and the solid arrangement portion are separated by a non-arrangement portion, and the outer periphery of the island-shaped arrangement portion is surrounded by the solid arrangement portion, separated by the non-arrangement portion.

[0089] In addition to the solid arrangement portion and the island-shaped arrangement portion, the first thermal expansion adjustment layer may further have a linear arrangement portion in which the thermal expansion adjustment portions are arranged linearly and at least one end of the linear arrangement portion is connected to the island-shaped arrangement portion. In this case, the outer periphery of the linear arrangement portion and the island-shaped arrangement portion connected to the linear arrangement portion may be surrounded by the solid arrangement portion, with a non-arrangement portion between them.

[0090] The island-shaped arrangement portion may overlap at least a portion of the connection terminal when viewed from the stacking direction. When the island-shaped arrangement portion overlaps at least a portion of the connection terminal when viewed from the stacking direction, wiring can be drawn to the first thermal expansion adjustment layer through a via provided in an insulating layer adjacent to the first thermal expansion adjustment portion at a position overlapping the connection terminal of the insulating layer on the connection terminal side. Furthermore, if a via is provided in an insulating layer adjacent to the first thermal expansion adjustment portion at a position overlapping the insulating layer on the opposite side from the connection terminal, the island-shaped arrangement portion will be connected to each of the vias provided in the two adjacent insulating layers, and wiring from the connection terminal can be drawn to the insulating layer on the opposite side of the first thermal expansion adjustment layer from the connection terminal through the island-shaped arrangement portion.

[0091] The areas of the solid arrangement portion, the island arrangement portion, and the linear arrangement portion are all counted in the area of ​​the thermal expansion adjustment portion.

[0092] An example in which the placement portion has a solid placement portion and an island-shaped placement portion will be described with reference to Figure 8. Figure 8 is a diagram schematically illustrating a comparison between the positions of the connection terminals and the positions of the thermal expansion adjustment portions of the first thermal expansion adjustment layer when viewing yet another example of a wiring board from the stacking direction. That is, Figure 8 shows the positional relationship between the placement portion 22 and the non-placement portion 29 in the first thermal expansion adjustment layer 120 constituting the wiring board 5, and the connection terminal 40 when viewed from the stacking direction. In Figure 8, the location where the placement portion 22 where the thermal expansion adjustment portion is located and the connection terminal 40 overlap is also the location where the two overlap when viewing the wiring board 5 from the stacking direction.

[0093] 8 also shows the external shape of the wiring board 5. When the insulating layer 10 is viewed from the stacking direction, the external shape is a square with four sides (5c, 5d, 5e, 5f) of equal length.

[0094] There are a total of 16 connection terminals 40, which are divided into connection terminals 40a and 40b arranged on the outermost periphery and connection terminals 40c not arranged on the outermost periphery according to their positions. The connection terminals 40a and 40b arranged on the outermost periphery are further divided into connection terminals 40a arranged on the outermost corners and connection terminals 40b arranged on the outermost sides.

[0095] When viewed from the stacking direction as shown in FIG. 8 , the first thermal expansion adjustment layer 120 has an arrangement portion 22 where the thermal expansion adjustment portions are arranged and a non-arrangement portion 29 (291, 292) where no thermal expansion adjustment portions are arranged. The arrangement portion 22 consists of an island-shaped arrangement portion 23 where the thermal expansion adjustment portions are arranged in an island-like manner and a solid arrangement portion 25 where the thermal expansion adjustment portions are arranged in a solid manner. The island-shaped arrangement portion 23 and the solid arrangement portion 25 are separated by the non-arrangement portion 292, and the solid arrangement portion 25 surrounds the periphery of the non-arrangement portion 292. In other words, the periphery of the island-shaped arrangement portion 23 is surrounded by the solid arrangement portion 25, separated by the non-arrangement portion 292. Furthermore, when comparing the positions of the connection terminals and the thermal expansion adjustment portions of the first thermal expansion adjustment layer when viewed from the stacking direction, the island-shaped arrangement portion 23 overlaps at least a portion of the connection terminal 40.

[0096] As described above, when the island-shaped arrangement portion overlaps at least a part of the connection terminal when viewed from the stacking direction, the thermal expansion adjustment portion (island-shaped arrangement portion) functioning as a wiring drawn from the connection terminal can be prevented from contacting another thermal expansion adjustment portion (solid arrangement portion). This allows the connection terminal, which is the target for suppressing stress concentration, to be drawn above the first thermal expansion adjustment layer (the side opposite to the main surface on which the connection terminal is provided, from the second insulating layer onward) without being in electrical contact with the solid arrangement portion of the first thermal expansion adjustment layer, thereby increasing the degree of freedom in design.

[0097] In this case, the island-shaped portion of the first thermal expansion adjustment layer is preferably a conductor that connects to a via conductor provided in an insulating layer adjacent to the first thermal expansion adjustment layer in the stacking direction. For example, when the first thermal expansion adjustment layer is disposed between a first insulating layer, which is the first insulating layer counting from the first main surface, and a second insulating layer, which is the second insulating layer, the island-shaped portion is preferably a conductor that connects a first via conductor provided in the first insulating layer and a second via conductor provided in the second insulating layer. By configuring as described above, electrical continuity can be established between the first insulating layer and the second insulating layer, which face each other in the stacking direction via the first thermal expansion adjustment layer, without electrical contact with the solid-shaped portion.

[0098] The outer shape of the solid arrangement portion 25 shown in Fig. 8 is the same as the outer shape of the arrangement portion 22 shown in Fig. 5. However, in the first thermal expansion adjustment layer 120 shown in Fig. 8, the area of ​​the arrangement portion 22 is the total area of ​​the island-shaped arrangement portion 23 and the solid arrangement portion 25, and the area of ​​the non-arrangement portion 29 surrounding the outer periphery of the island-shaped arrangement portion 23 is not counted in the area of ​​the thermal expansion adjustment portion (area of ​​the arrangement portion 22). Therefore, in the wiring board 5 shown in Fig. 8, the ratio of the area of ​​the thermal expansion adjustment portion (area of ​​the arrangement portion 22) to the area of ​​the insulating layer 10 is 32.6%, which is smaller than the ratio (35.0%) of the area of ​​the thermal expansion adjustment portion (area of ​​the arrangement portion 22) to the area of ​​the insulating layer 10 in the wiring board 3 shown in Fig. 5.

[0099] The shape of the solid arrangement portion surrounding the periphery of the non-arrangement portion may be any shape as long as the island arrangement portion and the solid arrangement portion do not come into contact with each other due to the non-arrangement portion. For example, if the non-arrangement portion is exposed on a side surface of the wiring board, the portion of the periphery of the non-arrangement portion that is not exposed on the side surface of the wiring board may be surrounded by the solid arrangement portion. In other words, the solid arrangement portion may not cover the entire periphery of the non-arrangement portion. However, it is preferable that at least half of the periphery of the non-arrangement portion is surrounded by the solid arrangement portion.

[0100] Next, an example in which the arrangement portion further includes a linear arrangement portion in addition to the solid arrangement portion and the island-shaped arrangement portion will be described with reference to FIG. 9 . FIG. 9 is a diagram schematically illustrating a comparison between the positions of the connection terminals and the thermal expansion adjustment portion of the first thermal expansion adjustment layer when viewing yet another example of a wiring board from the stacking direction. The wiring board 5′ shown in FIG. 9 can be said to be a wiring board 5 shown in FIG. 8 in which the shapes of the arrangement portion 22 and the non-arrangement portion 29 in the first thermal expansion adjustment layer 120 have been changed. Specifically, the island-shaped arrangement portions 23, which were independently arranged in two locations in the wiring board 5 shown in FIG. 8, are connected via a linear arrangement portion 27 in the wiring board 5′ shown in FIG. 9 . Therefore, the linear arrangement portion 27 and the island arrangement portions 23 connected to both ends of the linear arrangement portion 27 are separated from the solid arrangement portion 25 by the non-arrangement portion 292, and it can be said that the outer peripheries of the linear arrangement portion 27 and the island arrangement portions 23 connected to both ends of the linear arrangement portion 27 are surrounded by the solid arrangement portion 25, separated by the non-arrangement portion 29.

[0101] The linear arrangement portion 27 and the island arrangement portions 23 connected to both ends of the linear arrangement portion 27 are separated from the solid arrangement portion 25 by the non-arrangement portion 292, and are therefore not electrically connected within the first thermal expansion adjustment layer 120. However, even arrangement portions that are not electrically connected within the first thermal expansion adjustment layer may be electrically connected after being drawn out to another thermal expansion adjustment layer via an insulating layer.

[0102] The outer shape of the solid arrangement portion 25 shown in Fig. 9 is the same as the outer shape of the solid arrangement portion 25 shown in Fig. 8. Therefore, the ratio of the area of ​​the thermal expansion adjustment portion (area of ​​arrangement portion 22) to the area of ​​the insulating layer 10 in the wiring board 5' shown in Fig. 9 is 30.8%, which is smaller than the ratio (32.6%) of the area of ​​the thermal expansion adjustment portion (area of ​​arrangement portion 22) to the area of ​​the insulating layer 10 in the wiring board 5 shown in Fig. 8.

[0103] In the wiring board of the present invention, a plurality of solid arrangement portions, island arrangement portions, linear arrangement portions and non-arrangement portions may be provided. An example of such a wiring board will be described with reference to FIG.

[0104] 10 is a diagram schematically illustrating a comparison between the positions of the connection terminals and the positions of the thermal expansion adjustment portions of the first thermal expansion adjustment layer when viewing another example of a wiring board from the stacking direction. FIG. 10 shows the positional relationship between the arrangement portion 22 and non-arrangement portion 29 in the first thermal expansion adjustment layer 120 constituting the wiring board 6 and the connection terminal 40 when viewed from the stacking direction. The arrangement portion 22 is composed of arrangement portions 221, 222, 223, 224, 225, and 226, each of which consists of seven island-shaped arrangement portions 23 (231, 232, 233, 234, 235, 236, and 237), two solid arrangement portions 25 (251 and 252), and four linear arrangement portions 27 (271, 272, 273, and 274). The non-arrangement portion 29 is composed of four non-arrangement portions 29 (291, 292, 293, and 294).

[0105] Arrangement portion 221 is made up of linear arrangement portion 271, one end of which overlaps connection terminal 40a arranged at the outermost corner, and island-shaped arrangement portion 231, which is connected to the other end of linear arrangement portion 271. Arrangement portion 222 is made up of island-shaped arrangement portion 232, which overlaps connection terminal 40b arranged on the outermost side, linear arrangement portion 272, one end of which is connected to island-shaped arrangement portion 232, and island-shaped arrangement portion 233, which is connected to the other end of linear arrangement portion 272.

[0106] The arrangement portion 223 is composed of an island-shaped arrangement portion 234 that overlaps the connection terminal 40b arranged on the outermost edge, a linear arrangement portion 273 whose one end is connected to this island-shaped arrangement portion 234, and an island-shaped arrangement portion 235 whose other end is connected.

[0107] The arrangement portion 224 is made up of two island-shaped arrangement portions 236 and 237 provided at positions where neither of them overlaps the connection terminal 40, and a linear arrangement portion 274 connecting these.

[0108] The placement portion 225 is composed of a solid placement portion 251 that is arranged so as to overlap the connection terminals 40b that are arranged on the outermost side.

[0109] The placement portion 226 is composed of a solid placement portion 252 that is arranged to cover the entire outer periphery of the placement portions 223 and 224 described above and a portion of the outer periphery of the placement portion 222. Portions of the placement portion 226 (solid placement portion 252) reach the second side surface 6d, the third side surface 6e, and the fourth side surface 6f of the wiring board 6. Therefore, it can be said that the placement portion 226 (solid placement portion 252) is exposed to three of the four side surfaces of the wiring board 6. A non-placement portion 294 is provided within the placement portion 226, and the above-mentioned placement portions 223 and 224 are further disposed within this non-placement portion 294. Therefore, the outer peripheries of the placement portions 223 and 224 are surrounded by the placement portion 226, which is composed of the solid placement portion 252, across the non-placement portion 294. Furthermore, a part of the outer periphery of the placement portion 222 is surrounded by a placement portion 226 formed of a solid placement portion 252, with a non-placement portion 292 in between.

[0110] In the wiring board 6 shown in FIG. 10, the ratio of the area of ​​the thermal expansion adjusting portion (area of ​​the placement portion 22) to the area of ​​the insulating layer 10 is 60.3%.

[0111] In the wiring board of the present invention, a resin layer may be provided on the first main surface. In this case, the connection terminal is preferably a through conductor that penetrates the resin layer. Examples of the through conductor include a metal pin, a metal plating formed in a through hole, and a fired body obtained by filling a through hole with a conductive paste and firing it. Among these, a metal pin (metal pin) is preferred. An example of a wiring board having a resin layer provided on the first main surface will be described with reference to FIG. 11.

[0112] 11 is a cross-sectional view schematically illustrating yet another example of a wiring board according to the present invention. In the wiring board 7 shown in FIG. 11 , a resin layer 50 is provided on the first main surface 7a side. The resin constituting the resin layer 50 has a thermal expansion coefficient greater than that of the thermal expansion adjusting material. The connection terminals 40 are through conductors 41 that penetrate the resin layer 50 in the stacking direction (the direction indicated by the arrow Z in FIG. 11 ). Terminals 30 may be exposed on the second main surface 7b of the wiring board 7. The terminals 30 are used when mounting electronic components on the second main surface 7b of the wiring board 7.

[0113] A resin layer made of a resin having a thermal expansion coefficient larger than that of the thermal expansion adjusting material is provided on the first main surface side in the stacking direction, and the connection terminal is preferably a through conductor penetrating through the resin layer. With the above configuration, a resin layer having a large thermal expansion coefficient is formed so as to cover the connection terminal (through conductor) which is susceptible to stress, so that the stress at the connection portion can be further alleviated. The resin constituting the resin layer is, for example, an epoxy resin (10x10 －６ [K －１ ] or more, 50 x 10 －６ [K －１ ] or less).

[0114] The height of the through conductor (thickness of the resin layer) is not particularly limited, but is preferably 50 μm or more and 600 μm or less. The diameter of the through conductor is not particularly limited, but is preferably 100 μm or more and 400 μm or less.

[0115] The thermal expansion coefficient of the material forming the through conductor may be the same as or greater than the thermal expansion coefficient of the thermal expansion adjusting material.

[0116] In the wiring board having the resin layer provided on the first main surface as described above, the thermal expansion adjusting portion may be exposed on the first main surface of the wiring board. In this case, it is preferable that the thermal expansion adjusting portion exposed on the first main surface is connected to the connection terminal. An example of a wiring board having the resin layer provided on the first main surface and the thermal expansion adjusting portion exposed on the first main surface will be described with reference to FIG.

[0117] FIG. 12 is a cross-sectional view schematically illustrating another example of a wiring board according to the present invention. In the wiring board 8 shown in FIG. 12 , a resin layer 50 is provided on the first main surface 8a. The resin constituting the resin layer 50 has a thermal expansion coefficient greater than that of the thermal expansion adjusting material. The connection terminals are through conductors 41 that penetrate the resin layer 50 in the stacking direction (the direction indicated by the arrow Z in FIG. 12 ). A thermal expansion adjusting portion 21 containing a thermal expansion adjusting material is exposed on the first main surface 8a of the wiring board 8 and is in contact with the through conductors 41 that penetrate adjacent resin layers 50 and the via conductors 11 that penetrate the insulating layer 10. The size of the thermal expansion adjusting portion 21 is set larger than the sizes of the through conductors 41 and the via conductors 11, thereby improving the contact between the through conductors 41 and the via conductors 11.

[0118] The thermal expansion adjusting portion of the first thermal expansion adjusting layer may or may not be exposed on the side surface of the wiring substrate.

[0119] In the wiring board of the present invention, electronic components may be mounted on the second main surface of the wiring board. When electronic components are mounted on the second main surface, a resin layer may be provided on the second main surface to seal the electronic components. An example of a wiring board having electronic components mounted on the second main surface will be described with reference to FIG.

[0120] Fig. 13 is a cross-sectional view schematically showing another example of a wiring board according to the present invention. The wiring board 9 shown in Fig. 13 has connection terminals 40 on a first main surface 9a and terminals 30 on a second main surface 9b. An electronic component 60 is mounted on the second main surface 9b. The electronic component 60 is connected to the terminals 30 via solder bumps 70. A resin layer 80 is provided on the second main surface 9b to seal the electronic component 60.

[0121] Examples of electronic components mounted on the second main surface include multilayer capacitors, multilayer inductors, filters, and ICs.

[0122] The resin constituting the resin layer provided on the second main surface of the wiring board can be the same as the resin constituting the resin layer provided on the first main surface of the wiring board.

[0123] [Method for manufacturing wiring board] The wiring board of the present invention can be obtained, for example, in a conventional method for manufacturing a wiring board, by printing a conductor pattern so that the area of ​​the conductor paste that will become the thermal expansion adjusting portion after firing is 20% or more and 50% or less of the area of ​​the insulating layer.

[0124] Specifically, a ceramic green sheet A on which a conductive paste is printed is prepared so that the area of ​​the conductive paste when the fired wiring board is viewed from the stacking direction is 20% or more and 50% or less of the area based on the external shape of the insulating layer when viewed from the stacking direction, and then laminated with a ceramic green sheet B on which a conductive paste is printed according to a normal design.

[0125] The conductive paste formed on the ceramic green sheet A becomes the thermal expansion adjusting portion that constitutes the first thermal expansion adjusting layer after firing. By adjusting the order in which the ceramic green sheets A are stacked, the position of the first thermal expansion adjusting layer in the stacking direction can be adjusted.

[0126] [Module] The module of the present invention is formed by mounting the wiring board of the present invention on a main board. Because the module of the present invention is formed by mounting the wiring board of the present invention on a main board, stress is less likely to occur at the connection portion (connection terminal or solder portion) between the wiring board and the main board, and damage to the connection portion can be suppressed.

[0127] The main substrate may be, for example, a printed circuit board. The thermal expansion coefficient of the printed circuit board in the horizontal direction is, for example, 10×10 －６ [K －１ ] or more, 30 x 10 －６ [K －１The main board may be a single-sided board, a double-sided board, or a multi-layer board.

[0128] This specification describes the following:

[0129] The present disclosure (1) is a wiring board formed by laminating an insulating layer and a thermal expansion adjustment layer in which a thermal expansion adjustment portion containing a thermal expansion adjustment material having a thermal expansion coefficient larger than that of the insulating layer is disposed, the wiring board having a connection terminal on a first main surface of the wiring board, and at least one layer of the thermal expansion adjustment layer is a first thermal expansion adjustment layer in which the area of ​​the thermal expansion adjustment portion when viewed from the stacking direction is 20% or more and 80% or less of the area based on the external shape of the insulating layer when viewed from the stacking direction.

[0130] The present disclosure (2) is the wiring board according to the present disclosure (1), in which, when viewed from the stacking direction, the thermal expansion adjustment portion of the first thermal expansion adjustment layer overlaps with at least a portion of the connection terminal.

[0131] The present disclosure (3) is a wiring board according to the present disclosure (1) or (2), which includes a plurality of the connection terminals, and when viewed from the stacking direction, the thermal expansion adjustment portion of the first thermal expansion adjustment layer overlaps with the connection terminals arranged at the outermost periphery of the wiring board.

[0132] The present disclosure (4) is the wiring board described in the present disclosure (3), wherein the external shape of the wiring board when viewed from above is a substantially rectangular shape having short sides and long sides, and when viewed from the stacking direction, the thermal expansion adjustment portion of the first thermal expansion adjustment layer overlaps across both the connection terminal adjacent to one of the short sides and the connection terminal adjacent to the other short side among the plurality of connection terminals.

[0133] The present disclosure (5) is a wiring board of any combination with any of the present disclosures (1) to (4), in which the first thermal expansion adjustment layer is disposed between a first insulating layer, which is the first insulating layer counting from the first main surface, and a second insulating layer, which is the second insulating layer.

[0134] The present disclosure (6) is a wiring board that is an arbitrary combination with any of the present disclosures (1) to (5), in which the first thermal expansion adjustment layer has a non-placement portion where the thermal expansion adjustment portion is not placed, a solid placement portion where the thermal expansion adjustment portion is placed in a solid pattern, and an island placement portion where the thermal expansion adjustment portion is placed in an island pattern.

[0135] The present disclosure (7) is the wiring board according to the present disclosure (6), wherein in the first thermal expansion adjustment layer, the island-shaped arrangement portion and the solid arrangement portion are separated by the non-arrangement portion, and the outer periphery of the island-shaped arrangement portion is surrounded by the solid arrangement portion across the non-arrangement portion.

[0136] The present disclosure (8) is the wiring board according to the present disclosure (6), wherein the first thermal expansion adjustment layer further has a linear arrangement portion in which the thermal expansion adjustment portion is arranged linearly and at least one end is connected to the island-shaped arrangement portion, the linear arrangement portion and the island-shaped arrangement portion connected to the linear arrangement portion are separated from the solid arrangement portion by the non-arrangement portion, and the outer periphery of the linear arrangement portion and the island-shaped arrangement portion connected to the linear arrangement portion is surrounded by the solid arrangement portion, with the non-arrangement portion separating them.

[0137] The present disclosure (9) is a wiring board in any combination with any of the present disclosures (6) to (8), in which the island-shaped arrangement portion overlaps at least a part of the connection terminal when viewed from the stacking direction.

[0138] The present disclosure (10) is a wiring board according to the present disclosure (8) or (9), wherein the island-shaped arrangement portion is a conductor that connects a first via conductor provided in a first insulating layer, which is the first insulating layer counting from the first main surface, and a second via conductor provided in a second insulating layer, which is the second insulating layer counting from the first main surface.

[0139] The present disclosure (11) is a wiring board in any combination with any of the present disclosures (1) to (10), in which the external dimensions of the thermal expansion adjustment portion of the first thermal expansion adjustment layer when viewed from the stacking direction are such that the width dimension is 1 / 2 or more of the width dimension of the wiring board, and / or the length dimension is 1 / 2 or more of the length dimension of the wiring board.

[0140] The present disclosure (12) is a wiring board in any combination with any of the present disclosures (1) to (11), in which a resin layer made of a resin having a thermal expansion coefficient larger than that of the thermal expansion adjusting material is provided on the first main surface side in the stacking direction, and the connection terminal is a through conductor that penetrates the resin layer.

[0141] The present disclosure (13) is a wiring board in any combination with any of the present disclosures (1) to (12), in which at least a part of the thermal expansion adjusting portion of the first thermal expansion adjusting layer is GND wiring.

[0142] The present disclosure (14) is a wiring board in any combination with any of the present disclosures (1) to (13), in which the thermal expansion adjustment portion of the first thermal expansion adjustment layer is not exposed on the side surface of the wiring board.

[0143] The present disclosure (15) is a wiring board in any combination with any of the present disclosures (1) to (13), in which the thermal expansion adjustment portion of the first thermal expansion adjustment layer is exposed on a side surface of the wiring board.

[0144] The present disclosure (16) is the wiring board according to any one of the present disclosures (1) to (15), in which the thermal expansion adjuster is a conductive material.

[0145] The present disclosure (17) is the wiring board according to the present disclosure (16), wherein the conductive material is at least one metal selected from the group consisting of Cu, Ag, Au, and alloys thereof.

[0146] DESCRIPTION OF SYMBOLS 1, 2, 3, 4, 4', 5, 5', 6, 7, 8, 9 Wiring board 1a, 7a, 8a, 9a First main surface of wiring board 1b, 7b, 8b, 9b Second main surface of wiring board 1c, 1d, 1e, 1f, 2c, 2d, 2e, 2f, 3c, 3d, 3e, 3f, 4c, 4d, 4e, 4f, 5c, 5d, 5e, 5f, 6c, 6d, 6e, 6f Side surface of wiring board 10 Insulating layer 11 Via conductor (thermal expansion adjustment portion) 20 Thermal expansion adjustment layer 21 Thermal expansion adjustment portion 22, 221, 222, 223, 224, 225, 226 Arrangement portion 23, 231, 232 Solid arrangement portion 25, 251, 252, 253, 254, 255, 256, 257 Island-shaped arrangement portion 27, 271, 272, 273, 274 Linear arrangement portion 29, 291, 292, 293, 294 Non-arrangement portion 30 Terminal (thermal expansion adjustment portion) 40 Connection terminal 40a Connection terminal arranged at outermost corner 40b Connection terminal arranged on outermost side 40c Connection terminal not arranged on outermost side 40d Connection terminal arranged on outermost short side 40e Connection terminal arranged on outermost long side 41 Connection terminal (through conductor) 50 Resin layer 60 Electronic component 70 Solder bump 80 Resin layer 101 First insulating layer 102 Second insulating layer 120 First thermal expansion adjustment layer S １０ Insulation layer area S ２２ Area of ​​thermal expansion adjustment portion (area of ​​arrangement portion) S ２９ Area of ​​non-placed part

Claims

1. A wiring board formed by laminating an insulating layer and a thermal expansion adjustment layer on which a thermal expansion adjustment section containing a thermal expansion adjustment material with a thermal expansion coefficient larger than that of the insulating layer is disposed, the wiring board having a connection terminal on a first main surface of the wiring board, and at least one layer of the thermal expansion adjustment layer being a first thermal expansion adjustment layer in which the area of ​​the thermal expansion adjustment section when viewed from the stacking direction is 20% or more and 80% or less of the area based on the external shape of the insulating layer when viewed from the stacking direction.

2. The wiring board according to claim 1, wherein the thermal expansion adjusting portion of the first thermal expansion adjusting layer overlaps with at least a portion of the connection terminal when viewed from the stacking direction.

3. A wiring board as described in claim 1 or 2, comprising a plurality of connection terminals, and when viewed from the stacking direction, the thermal expansion adjustment portion of the first thermal expansion adjustment layer overlaps with the connection terminals arranged on the outermost periphery of the wiring board.

4. The wiring board according to claim 3, wherein the external shape of the wiring board when viewed from above is a substantially rectangular shape having short sides and long sides, and when viewed from the stacking direction, the thermal expansion adjustment portion of the first thermal expansion adjustment layer overlaps both a connection terminal adjacent to one of the short sides and a connection terminal adjacent to the other short side of the plurality of connection terminals.

5. A wiring board according to any one of claims 1 to 4, wherein the first thermal expansion adjustment layer is disposed between a first insulating layer, which is the first insulating layer counting from the first main surface, and a second insulating layer, which is the second insulating layer.

6. A wiring board described in any one of claims 1 to 5, wherein the first thermal expansion adjustment layer has a non-placement portion where the thermal expansion adjustment portion is not placed, a solid placement portion where the thermal expansion adjustment portion is placed in a solid pattern, and an island placement portion where the thermal expansion adjustment portion is placed in an island pattern.

7. A wiring board as described in claim 6, wherein in the first thermal expansion adjustment layer, the island-shaped arrangement portion and the solid arrangement portion are separated by the non-arrangement portion, and the outer periphery of the island-shaped arrangement portion is surrounded by the solid arrangement portion across the non-arrangement portion.

8. The wiring board described in claim 6, wherein the first thermal expansion adjustment layer further has a linear arrangement portion in which the thermal expansion adjustment portions are arranged linearly and at least one end is connected to the island-shaped arrangement portion, the linear arrangement portion and the island-shaped arrangement portion connected to the linear arrangement portion are separated from the solid arrangement portion by the non-arrangement portion, and the outer periphery of the linear arrangement portion and the island-shaped arrangement portion connected to the linear arrangement portion is surrounded by the solid arrangement portion, with the non-arrangement portion separating them.

9. The wiring board according to any one of claims 6 to 8, wherein the island-shaped portion overlaps at least a part of the connection terminal when viewed from the stacking direction.

10. A wiring board as described in claim 8 or 9, wherein the island-shaped arrangement portion is a conductor that connects a first via conductor provided in a first insulating layer, which is the first insulating layer counting from the first main surface, and a second via conductor provided in a second insulating layer, which is the second insulating layer counting from the first main surface.

11. A wiring board described in any one of claims 1 to 10, wherein the external dimensions of the thermal expansion adjustment portion of the first thermal expansion adjustment layer when viewed from the stacking direction have a width dimension that is at least half the width dimension of the wiring board, and / or a length dimension that is at least half the length dimension of the wiring board.

12. A wiring board according to any one of claims 1 to 11, wherein a resin layer made of a resin having a thermal expansion coefficient greater than that of the thermal expansion adjusting material is provided on the first main surface side in the stacking direction, and the connection terminal is a through conductor that penetrates the resin layer.

13. The wiring board according to any one of claims 1 to 12, wherein at least a part of the thermal expansion adjusting portion of the first thermal expansion adjusting layer is a GND wiring.

14. The wiring board according to any one of claims 1 to 13, wherein the thermal expansion adjusting portion of the first thermal expansion adjusting layer is not exposed on a side surface of the wiring board.

15. The wiring board according to any one of claims 1 to 13, wherein the thermal expansion adjusting portion of the first thermal expansion adjusting layer is exposed on a side surface of the wiring board.

16. The wiring board according to any one of claims 1 to 15, wherein the thermal expansion adjusting material is a conductive material.

17. The wiring board according to claim 16, wherein the conductive material is at least one metal selected from the group consisting of Cu, Ag, Au, and alloys thereof.

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