Multilayer board and method for manufacturing the same

Abstract

In the present invention, a stack has a structure in which a plurality of insulator layers are stacked in an up-down direction. A first conductor layer is provided on an upper main surface of an insulator layer, and transmits a first signal. A second conductor layer is provided on the same main surface of the same insulator layer as the upper main surface or lower main surface of the insulator layer on which the first conductor layer is provided. The second conductor layer transmits a second signal having a higher frequency than the first signal. An upper conductor layer is provided above the second conductor layer. The thickness of the second conductor layer in the up-down direction is less than the thickness of the first conductor layer in the up-down direction.

Description

[Technical field]

[0001] The present invention relates to a multilayer board having a structure in which a plurality of insulating layers are stacked, and a method for manufacturing the multilayer board. [Background technology]

[0002] As an invention related to a conventional multilayer board, for example, a differential signal transmission line described in Patent Document 1 is known. This differential signal transmission line includes a plurality of flexible insulating sheets, a first transmission line layer, a second transmission line layer, a first ground line layer, and a second ground line layer. The plurality of flexible insulating sheets are stacked in the vertical direction. Signals having different frequencies are transmitted to the first transmission line layer and the second transmission line layer. The first ground line layer is provided on the first transmission line layer and the second transmission line layer. The second ground line layer is provided below the first transmission line layer and the second transmission line layer. In this way, a stripline structure is formed in the differential signal transmission line. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 11-282592 Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, in the differential signal transmission line described in Patent Document 1, there is a demand for reducing the transmission loss occurring in the first transmission line layer and the second transmission line layer through which signals having different frequencies are transmitted.

[0005] SUMMARY OF THE PRESENT DISCLOSURE An object of the present invention is to provide a multilayer board and a method for manufacturing the multilayer board that can reduce transmission loss that occurs in a first conductor layer and a second conductor layer through which signals of different frequencies are transmitted. [Means for solving the problem]

[0006] A multilayer substrate according to one embodiment of the present invention comprises: a laminate having a structure in which a plurality of insulating layers are laminated in a vertical direction; a first conductor layer provided on an upper main surface or a lower main surface of the insulating layer and through which a first signal is transmitted; The insulating layer on which the first conductor layer is provided The above Upper main surface or The above a second conductor layer provided on the same principal surface of the insulator layer as the lower principal surface, and through which a second signal having a higher frequency than the first signal is transmitted; provided on the laminate, and The above The second conductive layer is disposed above the first conductive layer and the second conductive layer so as to overlap the first conductive layer when viewed in the vertical direction. , which is a ground conductor layer An upper conductor layer; Equipped with The second conductor layer The above The thickness in the vertical direction is The above Smaller than the vertical thickness Ku , The distance between the upper conductor layer and the second conductor layer is greater than the distance between the upper conductor layer and the first conductor layer. .

[0007] A method for manufacturing a multilayer substrate according to one embodiment of the present invention includes the steps of: a laminate having a structure in which a plurality of insulating layers are laminated in a vertical direction; a first conductor layer provided on an upper main surface or a lower main surface of the insulating layer and through which a first signal is transmitted; a second conductor layer provided on the same principal surface of the insulator layer as the upper principal surface or the lower principal surface of the insulator layer on which the first conductor layer is provided, and through which a second signal having a higher frequency than the first signal is transmitted; an upper conductor layer that is a ground conductor layer and is provided in the laminate and is provided above the first conductor layer and the second conductor layer so as to overlap the second conductor layer when viewed in the up-down direction; Equipped with The thickness of the second conductor layer in the vertical direction is smaller than the thickness of the first conductor layer in the vertical direction, a distance between the upper conductor layer and the second conductor layer is larger than a distance between the upper conductor layer and the first conductor layer, the plurality of insulator layers include a first insulator layer and a second insulator layer; the first insulating layer and the second insulating layer are laminated below the upper conductor layer and above the first conductor layer and the second conductor layer so as to be adjacent to each other and arranged in this order from top to bottom, the plurality of insulator layers further includes a third insulator layer; the first conductor layer and the second conductor layer are provided on the third insulator layer, the material of the third insulating layer is the same as the material of the first insulating layer; the second insulator layer is an adhesive layer that bonds the first insulator layer and the third insulator layer, The material of the plurality of insulating layers includes a thermoplastic resin, a preparation step of preparing the third insulator layer, the third insulator layer having the first conductor layer and the second conductor layer, which have different thicknesses in the vertical direction, provided on either the upper main surface or the lower main surface; a compression bonding process of stacking the plurality of insulator layers including the third insulator layer in the vertical direction and then subjecting the plurality of insulator layers to a heat treatment and a pressure treatment; Equipped with. Further, a method for manufacturing a multilayer substrate according to one embodiment of the present invention includes the steps of: a laminate having a structure in which a plurality of insulating layers are laminated in a vertical direction; a first conductor layer provided on an upper main surface or a lower main surface of the insulating layer and through which a first signal is transmitted; a second conductor layer provided on the same principal surface of the insulator layer as the upper principal surface or the lower principal surface of the insulator layer on which the first conductor layer is provided, and through which a second signal having a higher frequency than the first signal is transmitted; an upper conductor layer that is a ground conductor layer and is provided in the laminate and is provided above the first conductor layer and the second conductor layer so as to overlap the second conductor layer when viewed in the up-down direction; It is equipped with The thickness of the second conductor layer in the vertical direction is smaller than the thickness of the first conductor layer in the vertical direction, a distance between the upper conductor layer and the second conductor layer is larger than a distance between the upper conductor layer and the first conductor layer, the plurality of insulator layers include a first insulator layer and a second insulator layer; the first insulating layer and the second insulating layer are laminated below the upper conductor layer and above the first conductor layer and the second conductor layer so as to be adjacent to each other and arranged in this order from top to bottom, the plurality of insulator layers further includes a third insulator layer; the first conductor layer and the second conductor layer are provided on the third insulator layer, the material of the third insulating layer is the same as the material of the first insulating layer; the second insulator layer is an adhesive layer that bonds the first insulator layer and the third insulator layer, a preparation step of preparing the third insulator layer, the third insulator layer having the first conductor layer and the second conductor layer, which have different thicknesses in the vertical direction, provided on either the upper main surface or the lower main surface; a compression bonding process in which the first insulating layer, the second insulating layer which is an adhesive layer not provided with a conductor layer, and the third insulating layer are laminated from top to bottom in this order, and then the first insulating layer, the second insulating layer, and the third insulating layer are subjected to a heat treatment and a pressure treatment; Equipped with.

[0008] A multilayer substrate according to one embodiment of the present invention comprises: a laminate having a structure in which a plurality of insulating layers are laminated in a vertical direction; a first conductor layer provided in an insulator layer of the plurality of insulator layers and through which a first signal is transmitted; a second conductor layer provided in an insulator layer of the plurality of insulator layers, through which a second signal having a higher frequency than the first signal is transmitted; an upper conductor layer that is provided on the laminate and is provided above the first conductor layer and the second conductor layer so as to overlap the second conductor layer when viewed in a vertical direction; Equipped with When viewed in a direction perpendicular to a transmission direction in which the first signal is transmitted, the second conductor layer overlaps the first conductor layer, The second conductor layer has a thickness in the vertical direction smaller than the thickness in the vertical direction of the first conductor layer.

[0009] A method for manufacturing a multilayer substrate according to one embodiment of the present invention includes the steps of: A preparation step of preparing a third insulator layer having a first conductor layer and a second conductor layer having different thicknesses in the vertical direction provided on either an upper main surface or a lower main surface; a compression bonding process in which a first insulator layer, a second insulator layer that is an adhesive layer not provided with a conductor layer, and the third insulator layer are laminated from top to bottom in this order, and then the first insulator layer, the second insulator layer, and the third insulator layer are subjected to a heat treatment and a pressure treatment; It is equipped with: Effect of the Invention

[0010] According to the multilayer board and the method for manufacturing the multilayer board of the present invention, it is possible to reduce the transmission loss occurring in the first conductor layer and the second conductor layer through which signals of different frequencies are transmitted. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is an exploded perspective view of a multilayer substrate 10. As shown in FIG. [Diagram 2] FIG. 2 is a cross-sectional view of the multilayer substrate 10 taken along line AA in FIG. [Diagram 3] FIG. 3 is a left side view of the electronic device 1 including the multilayer substrate 10. As shown in FIG. [Figure 4] FIG. 4 is a cross-sectional view of the multilayer substrate 10 during its manufacture. [Diagram 5] FIG. 5 is a cross-sectional view of the multilayer substrate 10 during its manufacture. [Figure 6] FIG. 6 is a cross-sectional view of the multilayer substrate 10 during its manufacture. [Figure 7] FIG. 7 is a cross-sectional view of the multilayer substrate 10 during its manufacture. [Figure 8] FIG. 8 is a cross-sectional view of the multilayer substrate 10 during its manufacture. [Figure 9] FIG. 9 is a cross-sectional view of multilayer substrate 10a. [Figure 10] FIG. 10 is a cross-sectional view of the multilayer substrate 10b. [Figure 11] FIG. 11 is a cross-sectional view of the multilayer substrate 10c. [Figure 12] FIG. 12 is a cross-sectional view of the multilayer substrate 10c during manufacture. [Figure 13] FIG. 13 is a cross-sectional view of the multilayer substrate 10c during manufacture. [Figure 14] FIG. 14 is a cross-sectional view of the multilayer substrate 10d. [Figure 15] FIG. 15 is a cross-sectional view of the multilayer substrate 10e. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] (Embodiment) [Structure of multilayer substrate 10] Hereinafter, a structure of a multilayer substrate 10 according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is an exploded perspective view of a multilayer substrate 10. Note that FIG. 1 shows a plurality of interlayer connection conductors. Body Representative interlayer connection conductors v3~v6 2 is a cross-sectional view of the multilayer substrate 10 taken along line AA in FIG.

[0013] In this specification, directions are defined as follows. The stacking direction of laminate 12 of multilayer substrate 10 is defined as the up-down direction. The extension direction of first conductor layer 22a of multilayer substrate 10 is defined as the front-rear direction. The line width direction of first conductor layer 22a is defined as the left-right direction. The up-down direction, front-rear direction, and left-right direction are perpendicular to each other.

[0014] In the following, X is a part or member of the multilayer substrate 10. In this specification, unless otherwise specified, each part of X is defined as follows. The front part of X means the front half of X. The rear part of X means the rear half of X. The left part of X means the left half of X. The right part of X means the right half of X. The upper part of X means the upper half of X. The lower part of X means the lower half of X. The front end of X means the front end of X. The rear end of X means the rear end of X. The left end of X means the left end of X. The right end of X means the right end of X. The upper end of X means the upper end of X. The lower end of X means the lower end of X. The front end of X means the front end of X and its vicinity. The rear end of X means the rear end of X and its vicinity. The left end of X means the left end of X and its vicinity. The right end of X means the right end of X and its vicinity. The upper end of X means the upper end of X and its vicinity. The lower end of X means the lower end of X and its vicinity.

[0015] First, the structure of a multilayer substrate 10 will be described with reference to Fig. 1. The multilayer substrate 10 transmits signals. The multilayer substrate 10 is used to electrically connect two circuits in electronic devices such as smartphones. As shown in Fig. 1, the multilayer substrate 10 includes a laminate 12, protective layers 20a and 20b, a first conductor layer 22a, a second conductor layer 22b, an upper conductor layer 24, a lower conductor layer 26, signal terminals 28a to 28d, a plurality of interlayer connection conductors v1, a plurality of interlayer connection conductors v2, and interlayer connection conductors v3 to v6.

[0016] The laminate 12 has a plate shape. Thus, the laminate 12 has an upper main surface and a lower main surface. The upper main surface and the lower main surface of the laminate 12 have normal lines extending in the up-down direction. The upper main surface and the lower main surface of the laminate 12 have a rectangular shape with long sides extending in the front-rear direction. Thus, the length of the laminate 12 in the front-rear direction is longer than the length of the laminate 12 in the left-right direction.

[0017] As shown in FIG. 1, the laminate 12 includes insulating layers 16a to 16c. The laminate 12 has a structure in which the insulating layers 16a to 16c are stacked in the vertical direction. The insulating layers 16a to 16c are arranged in this order from top to bottom. The insulating layers 16a to 16c have the same rectangular shape as the laminate 12 when viewed in the vertical direction. The insulating layers 16a to 16c are flexible dielectric sheets. The insulating layers 16a to 16c are made of a material containing a thermoplastic resin. The thermoplastic resin is, for example, a liquid crystal polymer, PTFE (polytetrafluoroethylene), or the like. The insulating layers 16a to 16c may also be made of polyimide. In this way, the laminate 12 is a main body made of an insulating material.

[0018] The first conductor layer 22a is provided on the laminate 12 (main body). The first conductor layer 22a is an insulating layer 16 among the multiple insulating layers. b The first conductor layer 22a is provided on the upper main surface or the lower main surface of the insulator layer 16b. In this embodiment, the first conductor layer 22a is provided on the upper main surface of the insulator layer 16b. The first conductor layer 22a has a linear shape. The first conductor layer 22a extends in the front-rear direction. A first signal is transmitted to the first conductor layer 22a. The first signal is, for example, a signal having a frequency of 0 MHz to several tens of MHz. The first signal is, for example, a DC signal that functions as a power source. The first signal is, for example, a high-frequency signal having a frequency of 13.56 MHz.

[0019] The second conductor layer 22b is provided on the laminate 12 (main body). The second conductor layer 22b is provided on the insulator layer 16b among the multiple insulator layers. Therefore, the second conductor layer 22b is provided on the same main surface of the insulator layer 16b on which the first conductor layer 22a is provided. Therefore, the vertical position of the second conductor layer 22b is the same as the vertical position of the first conductor layer 22a. In this embodiment, the second conductor layer 22b is provided on the upper main surface of the insulator layer 16b. As a result, the second conductor layer 22b overlaps the first conductor layer 22a when viewed in the orthogonal direction (left-right direction) perpendicular to the transmission direction (front-back direction) in which the first signal is transmitted. The second conductor layer 22b has a linear shape. The second conductor layer 22b extends in the front-back direction. The second conductor layer 22b is provided to the right of the first conductor layer 22a. A second signal having a higher frequency than the first signal is transmitted to the second conductor layer 22b. The second signal is, for example, a high-frequency signal having a frequency of 100 MHz or higher.

[0020] The upper conductor layer 24 is provided on the laminate 12 (main body). The upper conductor layer 24 is provided above the first conductor layer 22a and the second conductor layer 22b so as to overlap the second conductor layer 22b when viewed in the vertical direction. In this embodiment, the upper conductor layer 24 is provided on the laminate 12. The upper conductor layer 24 is provided above the first conductor layer 22a and the second conductor layer 22b so as to overlap the first conductor layer 22a and the second conductor layer 22b when viewed in the vertical direction. In this embodiment, the upper conductor layer 24 is provided on the upper main surface of the insulator layer 16a. The upper conductor layer 24 covers substantially the entire upper main surface of the insulator layer 16a. The upper conductor layer 24 is connected to a ground potential. Therefore, the upper conductor layer 24 is a ground conductor layer.

[0021] The lower conductor layer 26 is provided in the laminate 12 (main body). The lower conductor layer 26 is provided below the first conductor layer 22a and the second conductor layer 22b so as to overlap the second conductor layer 22b when viewed in the vertical direction. In this embodiment, the lower conductor layer 26 is provided in the laminate 12. The lower conductor layer 26 is provided below the first conductor layer 22a and the second conductor layer 22b so as to overlap the first conductor layer 22a and the second conductor layer 22b when viewed in the vertical direction. In this embodiment, the lower conductor layer 26 is provided on the lower main surface of the insulator layer 16c. In this embodiment, the lower conductor layer 26 covers substantially the entire lower main surface of the insulator layer 16c. The lower conductor layer 26 is connected to a ground potential. Therefore, the lower conductor layer 26 is a ground conductor layer. As a result, the first conductor layer 22a, the second conductor layer 22b, the upper conductor layer 24, and the lower conductor layer 26 have a stripline structure.

[0022] Here, as shown in FIG. 2, the thickness Tb of the second conductor layer 22b in the vertical direction is smaller than the thickness Ta of the first conductor layer 22a in the vertical direction. The thickness Ta is, for example, 17 μm or more and 35 μm or less. The thickness Tb is, for example, 6 μm or more and 12 μm or less. The thickness Tb of the second conductor layer 22b in the vertical direction is substantially equal to the thickness Tc of the upper conductor layer 24 in the vertical direction and the thickness Td of the lower conductor layer 26 in the vertical direction. In other words, the thickness Ta of the first conductor layer 22a in the vertical direction is larger than the thickness Tc of the upper conductor layer 24 in the vertical direction and the thickness Td of the lower conductor layer 26 in the vertical direction. Since the first conductor layer 22a and the second conductor layer 22b have the above structure, the distance Da between the first conductor layer 22a and the upper conductor layer 24 in the vertical direction is smaller than the distance Db between the second conductor layer 22b and the upper conductor layer 24 in the vertical direction. small .

[0023] The interlayer connection conductors v1, v2 electrically connect the upper conductor layer 24 and the lower conductor layer 26. More specifically, the interlayer connection conductors v1, v2 penetrate the insulating layers 16a to 16c in the up-down direction. The upper ends of the interlayer connection conductors v1, v2 are connected to the upper conductor layer 24. The lower ends of the interlayer connection conductors v1, v2 are connected to the lower conductor layer 26. The interlayer connection conductors v1 are provided to the left of the first conductor layer 22a. The interlayer connection conductors v1 are arranged in a row at equal intervals in the front-rear direction. The interlayer connection conductors v2 are provided to the right of the second conductor layer 22b. The interlayer connection conductors v2 are arranged in a row at equal intervals in the front-rear direction.

[0024] The signal terminals 28a, 28c are provided at the front end of the upper main surface of the insulator layer 16a. The signal terminals 28a, 28c have a rectangular shape when viewed in the vertical direction. The signal terminal 28a overlaps with the front end of the first conductor layer 22a when viewed in the vertical direction. The signal terminal 28c overlaps with the front end of the second conductor layer 22b when viewed in the vertical direction. The upper conductor layer 24 is not provided around the signal terminals 28a, 28c so that the signal terminals 28a, 28c are insulated from the upper conductor layer 24.

[0025] The interlayer connection conductor v3 electrically connects the signal terminal 28a and the first conductor layer 22a. Specifically, the interlayer connection conductor v3 penetrates the insulator layer 16a in the vertical direction. The upper end of the interlayer connection conductor v3 is connected to the signal terminal 28a. The lower end of the interlayer connection conductor v3 is connected to the front end of the first conductor layer 22a. As a result, the signal terminal 28a is electrically connected to the first conductor layer 22a. The first signal is input / output to / from the first conductor layer 22a via the signal terminal 28a.

[0026] The interlayer connection conductor v5 electrically connects the signal terminal 28c and the second conductor layer 22b. Specifically, the interlayer connection conductor v5 penetrates the insulating layer 16a in the vertical direction. The upper end of the interlayer connection conductor v5 is connected to the signal terminal 28c. The lower end of the interlayer connection conductor v5 is connected to the front end of the second conductor layer 22b. In this way, the signal terminal 28c is electrically connected to the second conductor layer 22b. The second signal is transmitted to the signal terminal 28c. c , and inputs and outputs to the second conductor layer 22b.

[0027] The signal terminals 28b, 28d and the interlayer connection conductors v4, v6 are c The signal terminals 28b, 28d and the interlayer connection conductors v4, v6 have a structure symmetrical with respect to the front and rear of the signal terminals 28b, 28d and the interlayer connection conductors v3, v5. Therefore, a description of the signal terminals 28b, 28d and the interlayer connection conductors v4, v6 will be omitted.

[0028] The first conductor layer 22a, the second conductor layer 22b, the upper conductor layer 24, the lower conductor layer 26, and the signal terminals 28a to 28d as described above are formed, for example, by etching a conductor foil provided on the upper or lower main surfaces of the insulating layers 16a to 16c. The conductor foil is, for example, a copper foil. The interlayer connection conductors v1 to v6 are, for example, through-hole conductors. The through-hole conductors are fabricated by forming through-holes in the insulating layers 16a to 16c and subjecting the through-holes to a plating process. However, the interlayer connection conductors v1 to v6 may be via-hole conductors. The via-hole conductors are fabricated by forming through-holes in the insulating layers 16a to 16c, filling the through-holes with a conductive paste, and then sintering the conductive paste.

[0029] The protective layers 20a and 20b are flexible insulating layers. However, the protective layers 20a and 20b are not part of the laminate 12. The protective layers 20a and 20b have the same rectangular shape as the laminate 12 when viewed in the top-bottom direction.

[0030] The protective layer 20a covers substantially the entire upper main surface of the insulating layer 16a. Thus, the protective layer 20a protects the upper conductor layer 24. However, the protective layer 20a is provided with openings h1 to h8. The opening h1 overlaps with the signal terminal 28a when viewed in the vertical direction. Thus, the signal terminal 28a is exposed to the outside from the multilayer substrate 10 through the opening h1. The opening h2 overlaps with the signal terminal 28c when viewed in the vertical direction. Thus, the signal terminal 28c is exposed to the outside from the multilayer substrate 10 through the opening h2. The opening h3 is provided to the left of the opening h1. The opening h4 is provided to the right of the opening h2. Thus, the upper conductor layer 24 is exposed to the outside from the multilayer substrate 10 through the openings h3 and h4. The structures of the openings h5 to h8 are symmetrical to the structures of the openings h1 to h4, respectively. Therefore, the description of the openings h5 to h8 is omitted.

[0031] The protective layer 20b covers substantially the entire lower main surface of the insulating layer 16c, thereby protecting the lower conductor layer .

[0032] [Structure of Electronic Device 1] Next, the structure of the electronic device 1 including the multilayer substrate 10 will be described with reference to the drawings. Fig. 3 is a left side view of the electronic device 1 including the multilayer substrate 10. The electronic device 1 is, for example, a mobile wireless communication terminal. The electronic device 1 is, for example, a smartphone.

[0033] The multilayer substrate 10 is bent as shown in FIG. 3. "The multilayer substrate 10 is bent" means that an external force is applied to the multilayer substrate 10, causing the multilayer substrate 10 to deform and bend. Hereinafter, the section where the multilayer substrate 10 is bent is referred to as the bent section A2. The sections where the multilayer substrate 10 is not bent are referred to as the non-bent sections A1 and A3. The x-axis, y-axis, and z-axis of the electronic device 1 are defined as follows. The x-axis is the front-rear direction in the non-bent section A1. The y-axis is the left-right direction in the non-bent section A1. The z-axis is the up-down direction in the non-bent section A1. The non-bent section A1, the bent section A2, and the non-bent section A3 are arranged in this order toward the positive direction of the x-axis.

[0034] As shown in Fig. 3, the bending section A2 is bent in the z-axis direction. Therefore, the up-down direction and the front-rear direction differ depending on the position on the multilayer substrate 10, as shown in Fig. 3. In the non-bending section A1 and the non-bending section A3 where the laminate 12 is not bent (e.g., position (1)), the up-down direction and the front-rear direction respectively coincide with the z-axis direction and the x-axis direction. On the other hand, in the bending section A2 where the laminate 12 is bent (e.g., position (2)), the up-down direction and the front-rear direction respectively do not coincide with the z-axis direction and the x-axis direction.

[0035] The electronic device 1 includes a multi-layer substrate 10, connectors 30a, 30b, 102a, and 102b, and circuit boards 100 and 110, as shown in FIG.

[0036] The circuit boards 100 and 110 have a plate shape. The circuit board 100 has main surfaces S5 and S6. The main surface S5 is located on the negative side of the z axis from the main surface S6. The circuit board 110 has main surfaces S11 and S12. The main surface S11 is located on the negative side of the z axis from the main surface S12. The circuit boards 100 and 110 include wiring conductor layers, ground conductor layers, electrodes, etc., which are not shown.

[0037] The connectors 30a and 30b are mounted on the principal surfaces (upper principal surfaces) on the positive side of the z-axis of the non-bending sections A1 and A3. More specifically, the connector 30a is mounted on the signal terminals 28a and 28c exposed from the openings h1 to h4 and the upper conductor layer 24. The connector 30b is mounted on the signal terminals 28b and 28d exposed from the openings h5 to h8 and the upper conductor layer 24.

[0038] The connectors 102a and 102b are mounted on the main surface S5 of the circuit board 100 and the main surface S11 of the circuit board 110, respectively. The connectors 102a and 102b are connected to the connectors 30a and 30b, respectively. In this way, the multilayer board 10 electrically connects the circuit board 100 and the circuit board 110.

[0039] [Method of manufacturing multilayer substrate 10] A method for manufacturing the multilayer substrate 10 will be described below with reference to the drawings. Figures 4 to 6 are cross-sectional views of the multilayer substrate 10 during its manufacture.

[0040] First, an insulator layer 16b (third insulator layer) is prepared, in which a first conductor layer 22a and a second conductor layer 22b having different thicknesses in the vertical direction are provided on either the upper or lower main surface (preparation step). In this embodiment, an insulator layer 16b (third insulator layer) is prepared, in which a first conductor layer 22a and a second conductor layer 22b having different thicknesses in the vertical direction are provided on the upper main surface. More specifically, as shown in FIG. 4, a conductor foil is formed on the insulator layer 16b (conductor foil preparation step). In this embodiment, a copper foil 122 is attached to the upper main surface of the insulator layer 16b.

[0041] Next, a mask (not shown) is formed on the portion where the first conductor layer 22a and the second conductor layer 22b are to be formed, and the copper foil 122 is etched (patterning process). At this stage, as shown in FIG 4, the thickness Ta of the first conductor layer 22a in the vertical direction and the thickness Tb of the second conductor layer 22b in the vertical direction are equal to each other.

[0042] 4, the first conductor layer 22a (part of the conductor foil) is plated to make the thickness Ta of the first conductor layer 22a larger than the thickness Tb of the second conductor layer 22b (plating step). More specifically, a mask (not shown) is formed on the second conductor layer 22b. Then, only the first conductor layer 22a is plated.

[0043] Although not shown, conductor foil is formed on the upper main surface of the insulating layer 16a and the lower main surface of the insulating layer 16c, and the conductor foil is then etched to form the upper conductor layer 24 and the lower conductor layer 26.

[0044] Next, as shown in Fig. 5, the insulator layers 16a to 16c including the insulator layer 16b (third insulator layer) are stacked in the vertical direction. Thereafter, as shown in Fig. 6, the insulator layers 16a to 16c are subjected to a heat treatment and a pressure treatment (pressure bonding process). This causes the insulator layers 16a to 16c made of thermoplastic resin to soften and flow, and the insulator layers 16a to 16c are bonded to each other. As a result, the laminate 12 is obtained.

[0045] Next, Figure 1 The interlayer connection conductors v1 to v6 are formed as shown in Fig. 1. The interlayer connection conductors v1 to v6 are produced by forming through holes in the insulating layers 16a to 16c and subjecting the through holes to a plating process.

[0046] Finally, the upper main surface of the insulating layer 16a and the insulating layer 16 c Protective layers 20a and 20b are then formed on the lower principal surfaces of the first and second substrates 10 and 10 by printing.

[0047] [effect] According to the multilayer substrate 10, it is possible to reduce the transmission loss occurring in the first conductor layer 22a and the second conductor layer 22b through which signals of different frequencies are transmitted. More specifically, in order to reduce the transmission loss occurring in the first conductor layer 22a and the second conductor layer 22b, for example, it is considered to increase the thickness Ta in the vertical direction of the first conductor layer 22a and the thickness Tb in the vertical direction of the second conductor layer 22b. In this case, it is possible to reduce the DC resistance value of the first conductor layer 22a and the second conductor layer 22b.

[0048] However, in the multilayer substrate 10, a second signal having a higher frequency than the first signal is transmitted to the second conductor layer 22b. In such a second conductor layer 22b, in order to reduce the transmission loss of the second conductor layer 22b, it is necessary to make the characteristic impedance generated in the second conductor layer 22b approach a predetermined characteristic impedance (for example, 50Ω). Therefore, the line width in the left-right direction of the second conductor layer 22b and the distance D in the up-down direction between the second conductor layer 22b and the upper conductor layer 24 are adjusted so that the characteristic impedance generated in the second conductor layer 22b approaches the predetermined characteristic impedance. bHere, when the thickness Ta of the first conductor layer 22a in the vertical direction and the thickness Tb of the second conductor layer 22b in the vertical direction are increased as described above, the distance D b becomes smaller than the design value. As a result, the capacitance value generated between the second conductor layer 22b and the upper conductor layer 24 becomes larger than the design value, and the characteristic impedance generated in the second conductor layer 22b varies from a predetermined characteristic impedance. Therefore, it is difficult to reduce the transmission loss generated in the second conductor layer 22b.

[0049] In this way, when the frequency of the first signal transmitted through the first conductor layer 22a is different from the frequency of the second signal transmitted through the second conductor layer 22b, the condition for reducing the transmission loss of the first conductor layer 22a is different from the condition for reducing the transmission loss of the second conductor layer 22b. Therefore, it is difficult to reduce the transmission loss occurring in the first conductor layer 22a and the second conductor layer 22b by increasing the vertical thickness Ta of the first conductor layer 22a and the vertical thickness Tb of the second conductor layer 22b.

[0050] Therefore, in the multilayer substrate 10, the thickness Tb in the vertical direction of the second conductor layer 22b is smaller than the thickness Ta in the vertical direction of the first conductor layer 22a. This prevents the capacitance value generated between the second conductor layer 22b and the upper conductor layer 24 from becoming larger than the design value, and prevents the characteristic impedance generated in the second conductor layer 22b from fluctuating from the predetermined characteristic impedance. Furthermore, since the capacitance value generated between the second conductor layer 22b and the upper conductor layer 24 is prevented from becoming larger, it becomes easy to increase the line width in the horizontal direction of the second conductor layer 22b. This makes it easy to increase the length of the outer edge in the cross section perpendicular to the front-rear direction of the second conductor layer 22b. As a result, when the second signal flows intensively on the surface of the second conductor layer 22b due to the skin effect, the area in the second conductor layer 22b through which the second signal can flow tends to become wider. Therefore, the transmission loss of the second conductor layer 22b is easy to be reduced. As described above, according to the multilayer substrate 10, it is possible to reduce the transmission loss occurring in the first conductor layer 22a and the second conductor layer 22b through which signals of different frequencies are transmitted.

[0051] (First Modification) A method for manufacturing the multilayer substrate 10 according to the first modified example will be described below with reference to the drawings. Fig. 7 is a cross-sectional view of the multilayer substrate 10 during its manufacture.

[0052] The manufacturing method of the multilayer substrate 10 according to the first modification is different from the manufacturing method of the multilayer substrate 10 according to the above embodiment in a preparation step. More specifically, as shown in Fig. 7, a conductor foil is formed on the insulator layer 16b (third insulator layer) (conductor foil forming step). In this modification, a copper foil 122 is attached to the upper main surface of the insulator layer 16b.

[0053] Next, a mask (not shown) is formed on the portion where the first conductor layer 22a and the second conductor layer 22b are to be formed, and the copper foil 122 is etched (patterning process). At this stage, as shown in FIG 7, the thickness Ta of the first conductor layer 22a in the vertical direction and the thickness Tb of the second conductor layer 22b in the vertical direction are equal to each other.

[0054] Next, the first conductor layer 22 b By subjecting (a part of the conductor foil) to an etching process, the vertical thickness Tb of the second conductor layer 22b is made smaller than the vertical thickness Ta of the first conductor layer 22a (etching process). More specifically, a mask (not shown) is formed on the first conductor layer 22a. Then, the etching process is applied only to the second conductor layer 22b. Note that the other steps of the method for manufacturing the multilayer substrate 10 according to the first modified example are the same as those of the method for manufacturing the multilayer substrate 10 according to the embodiment, and therefore the description thereof will be omitted. The multilayer substrate 10 can also be obtained by the method for manufacturing the multilayer substrate 10 according to the first modified example.

[0055] (Second Modification) A method for manufacturing the multilayer substrate 10 according to the second modified example will be described below with reference to the drawings. Fig. 8 is a cross-sectional view of the multilayer substrate 10 during its manufacture.

[0056] The manufacturing method of the multilayer substrate 10 according to the second modification is different from the manufacturing method of the multilayer substrate 10 according to the embodiment in the preparation step. More specifically, as shown in FIG. 8, in the preparation step, the first conductor layer 22a and the second conductor layer 22b having different thicknesses in the vertical direction are attached to either the upper main surface or the lower main surface of the insulator layer 16b (third insulator layer). That is, the first conductor layer 22a and the second conductor layer 22b having different thicknesses in the vertical direction are prepared. Then, the first conductor layer 22a and the second conductor layer 22b are attached to the upper main surface of the insulator layer 16b. Note that the other steps of the manufacturing method of the multilayer substrate 10 according to the second modification are the same as those of the manufacturing method of the multilayer substrate 10 according to the embodiment, and therefore the description thereof will be omitted. The multilayer substrate 10 can also be obtained by the manufacturing method of the multilayer substrate 10 according to the second modification.

[0057] (Third Modification) A multilayer substrate 10a according to a third modified example will now be described with reference to the drawings. Fig. 9 is a cross-sectional view of the multilayer substrate 10a.

[0058] Multilayer substrate 10a differs from multilayer substrate 10 in that the vertical thickness of the left portion of laminate 12 is different from the vertical thickness of the right portion of laminate 12. This difference will be described below.

[0059] The laminate 12 further includes insulating layers 16d and 16e. The insulating layers 16d and 16e are laminated between the insulating layer 16b and the insulating layer 16c from top to bottom in this order.

[0060] The multilayer substrate 10a further includes ground conductor layers 30, 31, and 32. The ground conductor layers 30, 31, and 32 are located on the upper main surfaces of the insulating layers 16d, 16e, and 16c, respectively. The ground conductor layers 30, 31, and 32 overlap with the first conductor layer 22a when viewed in the up-down direction. The ground conductor layers 30, 31, and 32 do not overlap with the second conductor layer 22b when viewed in the up-down direction. This is to reduce the capacitance formed between the second conductor layer 22b and the ground conductor layers 30, 31, and 32, thereby suppressing deterioration of the high-frequency characteristics of the multilayer substrate 10a.

[0061] Here, the ground conductor layers 30, 31, and 32 do not overlap with the second conductor layer 22b when viewed in the top-bottom direction. Therefore, when the laminate 12 is compressed, the thickness of the left part of the laminate 12 in the top-bottom direction becomes larger than the thickness of the right part of the laminate 12 in the top-bottom direction.

[0062] Also in the multilayer substrate 10a, the distance Da between the first conductor layer 22a and the upper conductor layer 24 in the vertical direction is longer than the distance Db between the second conductor layer 22b and the upper conductor layer 24 in the vertical direction. small .

[0063] Other than that, the structure of the multilayer substrate 10a is the same as that of the multilayer substrate 10, and therefore a description thereof will be omitted. For the same reason as the multilayer substrate 10, the multilayer substrate 10a can reduce the transmission loss that occurs in the first conductor layer 22a and the second conductor layer 22b, through which signals of different frequencies are transmitted.

[0064] (Fourth Modification) A multilayer substrate 10b according to a fourth modified example will now be described with reference to the drawings. Fig. 10 is a cross-sectional view of the multilayer substrate 10b.

[0065] Multilayer substrate 10b differs from multilayer substrate 10a in that the boundaries between insulating layers 16a to 16e are not visible. In multilayer substrate 10b, second conductor layer 22b overlaps first conductor layer 22a when viewed in a direction perpendicular to the transmission direction in which the first signal is transmitted.

[0066] Other than that, the structure of the multilayer substrate 10b is the same as that of the multilayer substrate 10a, and therefore the description thereof will be omitted. For the same reason as the multilayer substrate 10a, the multilayer substrate 10b can reduce the transmission loss that occurs in the first conductor layer 22a and the second conductor layer 22b through which signals of different frequencies are transmitted.

[0067] (Fifth Modification) [Structure of multilayer board 10c] A multilayer substrate 10c according to a fifth modified example will now be described with reference to the drawings. Fig. 11 is a cross-sectional view of the multilayer substrate 10c.

[0068] Multilayer substrate 10c differs from multilayer substrate 10 in that it further includes insulator layer 18 instead of insulator layer 16c, and in that a lower conductor layer 26 is provided on the lower main surface of insulator layer 16b. Below, multilayer substrate 10c will be described, focusing on these differences.

[0069] The laminate 12 includes an insulating layer 16a (first insulating layer), an insulating layer 16b (third insulating layer), and an insulating layer 18 (second insulating layer). The insulating layer 16a (first insulating layer) and the insulating layer 18 (second insulating layer) are laminated below the upper conductor layer 24 and above the first conductor layer 22a and the second conductor layer 22b, in this order from top to bottom so as to be adjacent to each other. The insulating layer 16b is provided below the insulating layer 18. The boundary between the insulating layer 16a and the insulating layer 18 is located midway between the lower main surface of the upper conductor layer 24 and the lower main surface of the first conductor layer 22a and the lower main surface of the second conductor layer 22b. The material of the insulating layer 16b (third insulating layer) is the same as the material of the insulating layer 16a (first insulating layer). "The material of insulator layer 16b is the same as the material of insulator layer 16a" means that an error due to manufacturing variability is allowed. The material of insulator layer 18 is different from the materials of insulator layers 16a and 16b. Insulator layer 18 (second insulator layer) is an adhesive layer that bonds insulator layer 16a (first insulator layer) and insulator layer 16b (third insulator layer). The dielectric constant of insulator layer 18 (second insulator layer) is lower than the dielectric constant of insulator layer 16a (first insulator layer). Furthermore, the dielectric loss tangent of insulator layer 18 (second insulator layer) is lower than the dielectric loss tangent of insulator layer 16a (first insulator layer). 16a The dielectric loss tangent of the insulating layer 18 is lower than that of the insulating layer 14. A material for the insulating layer 18 that satisfies these conditions is, for example, a fluorine-based resin. However, the material for the insulating layer 18 may also be an epoxy resin, an acrylic resin, or the like.

[0070] The first conductor layer 22a and the second conductor layer 22b are provided on the insulating layer 16b (third insulating layer). Variations In this example, the first conductor layer 22a and the second conductor layer 22b are provided on the upper main surface of the insulator layer 16b (third insulator layer). The upper conductor layer 24 is provided on the insulator layer 16a (first insulator layer). VariationsIn the multilayer substrate 10c, the upper conductor layer 24 is provided on the upper main surface of the insulator layer 16a (first insulator layer). The lower conductor layer 26 is provided on the lower main surface of the insulator layer 16b (third insulator layer). The rest of the structure of the multilayer substrate 10c is the same as that of the multilayer substrate 10, so a description thereof will be omitted.

[0071] [Method of manufacturing the multilayer substrate 10c] A method for manufacturing the multilayer substrate 10c will be described below with reference to the drawings. Figures 12 and 13 are cross-sectional views of the multilayer substrate 10c during its manufacture.

[0072] First, an insulator layer 16b (third insulator layer) is prepared, in which a first conductor layer 22a and a second conductor layer 22b having different thicknesses in the vertical direction are provided on either the upper or lower main surface (preparation step). In this modification, an insulator layer 16b (third insulator layer) is prepared, in which a first conductor layer 22a and a second conductor layer 22b having different thicknesses in the vertical direction are provided on the upper main surface. More specifically, as shown in FIG. 12, a conductor foil is formed on the insulator layer 16b (conductor foil preparation step). In this modification, Variations Next, copper foils 122 and 126 are attached to the upper and lower main surfaces of the insulating layer 16b, respectively.

[0073] Next, a mask (not shown) is formed on the portion where the first conductor layer 22a and the second conductor layer 22b are to be formed, and the copper foil 122 is etched. Similarly, a mask (not shown) is formed on the portion where the lower conductor layer 26 is to be formed, and the copper foil 126 is etched. At this stage, as shown in Fig. 12, the thickness Ta in the vertical direction of the first conductor layer 22a and the thickness Tb in the vertical direction of the second conductor layer 22b are equal. Note that the etching of the copper foil 122 and the etching of the copper foil 126 may be performed simultaneously.

[0074] 12, the first conductor layer 22a (part of the conductor foil) is plated to make the thickness Ta of the first conductor layer 22a in the vertical direction larger than the thickness Tb of the second conductor layer 22b in the vertical direction (plating step). More specifically, a mask (not shown) is formed on the second conductor layer 22b and the lower conductor layer 26. Then, only the first conductor layer 22a is plated.

[0075] Although not shown in the drawings, a conductor foil is formed on the upper main surface of the insulating layer 16a, and the conductor foil is then etched to form the upper conductor layer 24.

[0076] Next, the insulating layer 16a (first insulating layer), the insulating layer 18 (second insulating layer) which is an adhesive layer not provided with a conductor layer, and the insulating layer 16b (third insulating layer) are laminated from top to bottom in this order. 8 In the adhesive layer forming step, for example, a liquid resin is applied to the upper main surface of the insulating layer 16b. of 8 The insulator layer 16a is placed on top of the insulator layer 16a (placement step). After that, the insulator layer 16a (first insulator layer), the insulator layer 16b (third insulator layer), and the insulator layer 18 (adhesive layer) are subjected to a heat treatment and a pressure treatment (compression bonding step). As a result, the insulator layer 18 functions as an adhesive layer to bond the insulator layer 16a and the insulator layer 16b. When a further insulator layer is to be stacked on the insulator layer 16a, the adhesive layer formation step, the placement step, and the compression bonding step are repeated.

[0077] Next, as shown in Fig. 11, the interlayer connection conductors v1 to v6 are formed. ,18,16b It is produced by forming a through hole in c and subjecting the through hole to a plating treatment.

[0078] Finally, protective layers 20a and 20b are formed by printing on the upper main surface of insulator layer 16a and the lower main surface of insulator layer 16b, respectively. Through the above steps, multi-layer substrate 10c is completed.

[0079] [effect] For the same reason as with multilayer substrate 10, multilayer substrate 10c can reduce transmission loss that occurs in first conductor layer 22a and second conductor layer 22b through which signals of different frequencies are transmitted.

[0080] Moreover, according to the multilayer substrate 10c, the transmission loss of the second conductor layer 22b can be reduced more effectively. More specifically, the insulator layers 16a and 18 are stacked in this order from top to bottom below the upper conductor layer 24 and above the first conductor layer 22a and the second conductor layer 22b so as to be adjacent to each other. The dielectric constant of the insulator layer 18 is lower than that of the insulator layer 16a. The dielectric loss tangent of the insulator layer 18 is lower than that of the insulator layer 16a. This reduces the dielectric constant and dielectric loss tangent in the vicinity of the second conductor layer 22b. As a result, when the second signal, which is a high-frequency signal, is transmitted to the second conductor layer 22b, the occurrence of dielectric loss in the second conductor layer 22b is suppressed. As a result, according to the multilayer substrate 10c, the transmission loss of the second conductor layer 22b can be reduced more effectively.

[0081] In the multilayer substrate 10c, the material of the insulating layers 16a and 16b may or may not be a thermoplastic resin.

[0082] (Sixth Modification) A multilayer substrate 10d according to a sixth modified example will now be described with reference to the drawings. Fig. 14 is a cross-sectional view of the multilayer substrate 10d.

[0083] The multilayer substrate 10d differs from the multilayer substrate 10 in that it further includes ground conductor layers 27a and 27b. The ground conductor layers 27a and 27b are connected to a ground potential. The ground conductor layers 27a and 27b are provided on the upper main surface of the insulator layer 16b. The ground conductor layer 27a is provided between the first conductor layer 22a and the second conductor layer 22b. The ground conductor layer 27b is provided to the right of the second conductor layer 22b. The rest of the structure of the multilayer substrate 10d is the same as that of the multilayer substrate 10, so a description thereof will be omitted.

[0084] For the same reason as in the case of the multilayer substrate 10, the multilayer substrate 10d can reduce the transmission loss that occurs in the first conductor layer 22a and the second conductor layer 22b through which signals of different frequencies are transmitted.

[0085] In the multilayer substrate 10d, the ground conductor layer 27a is provided between the first conductor layer 22a and the second conductor layer 22b, thereby improving the isolation between the first conductor layer 22a and the second conductor layer 22b.

[0086] In the multilayer substrate 10d, the ground conductor layers 27a and 27b may be electrically connected to at least one of the upper conductor layer 24 and the lower conductor layer 26 by an interlayer connection conductor, so that the potential of the ground conductor layers 27a and 27b is stabilized at the ground potential.

[0087] (Seventh Modification) A multilayer substrate 10e according to a seventh modified example will now be described with reference to the drawings. Fig. 15 is a cross-sectional view of the multilayer substrate 10e.

[0088] The multilayer substrate 10e differs from the multilayer substrate 10c in that it further includes ground conductor layers 27a and 27b. The ground conductor layers 27a and 27b are connected to a ground potential. The ground conductor layers 27a and 27b are provided on the upper main surface of the insulator layer 16b. The ground conductor layer 27a is provided between the first conductor layer 22a and the second conductor layer 22b. The ground conductor layer 27b is provided to the right of the second conductor layer 22b. The rest of the structure of the multilayer substrate 10e is the same as that of the multilayer substrate 10c, so a description thereof will be omitted.

[0089] For the same reason as in the multilayer board 10c, the multilayer board 10e can reduce the transmission loss that occurs in the first conductor layer 22a and the second conductor layer 22b through which signals of different frequencies are transmitted.

[0090] In the multilayer substrate 10e, the ground conductor layer 27a is provided between the first conductor layer 22a and the second conductor layer 22b, thereby improving the isolation between the first conductor layer 22a and the second conductor layer 22b.

[0091] (Other embodiments) The multilayer board according to the present invention is not limited to multilayer boards 10, 10a to 10e and can be modified within the scope of the present invention. The configurations of multilayer boards 10, 10a to 10e may be combined in any desired manner.

[0092] Alternatively, the insulating layers 16a to 16c may have a structure in which glass cloth is impregnated with epoxy resin, in which case the multilayer substrates 10, 10a to 10e do not have flexibility.

[0093] In the multilayer substrates 10, 10a to 10e, the lower conductor layer 26 is not an essential component. In this case, the first conductor layer 22a and the upper conductor layer 24 have a microstrip line structure. Similarly, the second conductor layer 22b and the upper conductor layer 24 have a microstrip line structure.

[0094] In the multilayer boards 10, 10a to 10e, the interlayer connection conductors v1, v2 are not essential components.

[0095] The multilayer boards 10, 10a to 10e are transmission lines. However, the multilayer boards 10, 10a to 10e may be circuit boards. Therefore, the multilayer boards 10, 10a to 10e may further include other circuits in addition to the strip lines.

[0096] In the multilayer boards 10 and 10a to 10e, the signal terminals 28a to 28d may be provided on the lower main surface of the laminate 12.

[0097] In addition, electronic components other than the connectors 30a and 30b may be mounted on the multilayer boards 10, 10a to 10e.

[0098] Note that multilayer substrates 10, 10a to 10e have a straight shape when viewed in the vertical direction. However, multilayer substrates 10, 10a to 10e may be curved. Here, "multilayer substrates 10, 10a to 10e are curved" means that multilayer substrates 10, 10a to 10e have a curved shape when no external force is applied to them.

[0099] The first conductor layer 22a and the second conductor layer 22b do not have to extend in parallel.

[0100] The insulating layer 18 may be formed by attaching a resin sheet to the upper main surface of the insulating layer 16b.

[0101] The dielectric constant of the insulator layer 18 may be equal to or greater than the dielectric constant of the insulator layer 16a, and the dielectric tangent of the insulator layer 18 may be lower than the dielectric tangent of the insulator layer 16a. The dielectric constant of the insulator layer 18 may be lower than the dielectric constant of the insulator layer 16a, and the dielectric tangent of the insulator layer 18 may be equal to or greater than the dielectric tangent of the insulator layer 16a. The dielectric constant of the insulator layer 18 may be equal to or greater than the dielectric constant of the insulator layer 16a, and the dielectric tangent of the insulator layer 18 may be equal to or greater than the dielectric tangent of the insulator layer 16a.

[0102] The method for manufacturing the multilayer substrate 10 according to the embodiment and the method for manufacturing the multilayer substrate 10 according to the fifth modified example c In the manufacturing method of the above, a patterning step may be carried out after the plating step.

[0103] In the method for manufacturing the multilayer substrate 10 according to the first modification, a patterning step may be performed after the etching step.

[0104] The upper conductor layer 24 and the lower conductor layer 26 may be connected to a potential other than the ground potential.

[0105] The upper conductor layer 24 does not necessarily have to overlap with the first conductor layer 22a when viewed in the up-down direction.

[0106] It should be noted that the lower conductor layer 26 does not necessarily have to overlap with the first conductor layer 22a when viewed in the up-down direction.

[0107] In the multilayer substrate 10a, the second conductor layer 22b may overlap the first conductor layer 22a when viewed in a direction perpendicular to the transmission direction in which the first signal is transmitted. [Explanation of symbols]

[0108] 1:Electronic equipment 10,10a~10e: Multilayer board 12: Laminate 16a to 16e, 18: Insulator layer 20a, 20b: Protective layer 22a: First conductor layer 22b: Second conductor layer 24: Upper conductor layer 26: Lower conductor layer 27a, 27b, 30-32: Ground conductor layers 28a~28d: Signal terminal 122,126:Copper foil

Claims

1. a laminate having a structure in which a plurality of insulating layers are laminated in a vertical direction; a first conductor layer provided on an upper main surface or a lower main surface of the insulating layer, the first conductor layer transmitting a first signal; a second conductor layer provided on the same principal surface of the insulator layer as the upper principal surface or the lower principal surface of the insulator layer on which the first conductor layer is provided, and through which a second signal having a higher frequency than the first signal is transmitted; an upper conductor layer that is a ground conductor layer and is provided in the laminate and is provided above the first conductor layer and the second conductor layer so as to overlap the second conductor layer when viewed in the up-down direction; It is equipped with The thickness of the second conductor layer in the vertical direction is smaller than the thickness of the first conductor layer in the vertical direction, a distance between the upper conductor layer and the second conductor layer is greater than a distance between the upper conductor layer and the first conductor layer; Multilayer board.

2. An insulating layer that is a part of the plurality of insulating layers is also located below the first conductor layer and the second conductor layer, a lower conductor layer serving as a ground conductor layer is provided below the first conductor layer and the second conductor layer; When viewed from the top-bottom direction, the second conductor layer overlaps the upper conductor layer and the lower conductor layer. The multilayer substrate according to claim 1 .

3. An insulating layer that is a part of the plurality of insulating layers is also located below the first conductor layer and the second conductor layer, The first conductor layer and the second conductor layer are both in contact with two of the plurality of insulator layers. The multilayer substrate according to claim 1 or 2.

4. A lower conductor layer is provided on the laminate and is provided below the first conductor layer and the second conductor layer so as to overlap the second conductor layer when viewed in the up-down direction, In addition, The multilayer substrate according to claim 1 .

5. the plurality of insulator layers include a first insulator layer and a second insulator layer; the first insulating layer and the second insulating layer are laminated below the upper conductor layer and above the first conductor layer and the second conductor layer so as to be adjacent to each other and arranged in this order from top to bottom, The dielectric constant of the second insulating layer is lower than the dielectric constant of the first insulating layer.

5. The multilayer board according to claim 1.

6. the plurality of insulator layers include a first insulator layer and a second insulator layer; the first insulating layer and the second insulating layer are laminated below the upper conductor layer and above the first conductor layer and the second conductor layer so as to be adjacent to each other and arranged in this order from top to bottom, The dielectric loss tangent of the second insulator layer is lower than the dielectric loss tangent of the first insulator layer.

5. The multilayer board according to claim 1.

7. the plurality of insulator layers further includes a third insulator layer; the first conductor layer and the second conductor layer are provided on the third insulator layer, the material of the third insulating layer is the same as the material of the first insulating layer; The second insulator layer is an adhesive layer that bonds the first insulator layer and the third insulator layer. The multilayer substrate according to claim 5 or 6.

8. The upper conductor layer is provided on the first insulating layer. The multilayer substrate according to claim 7.

9. A ground conductor layer provided between the first conductor layer and the second conductor layer, In addition, The multilayer board according to any one of claims 1 to 8.

10. The first signal is a DC signal that functions as a power source. The multilayer board according to any one of claims 1 to 9.

11. a distance between the second conductor layer and the upper conductor layer in the vertical direction is greater than a distance between the first conductor layer and the upper conductor layer in the vertical direction; The multilayer substrate according to any one of claims 1 to 10.

12. The upper conductor layer overlaps with the first conductor layer when viewed in the up-down direction. The multilayer substrate according to any one of claims 1 to 11.

13. The upper conductor layer is a ground conductor layer. The multilayer substrate according to any one of claims 1 to 12.

14. A body made of an insulating material; a first conductor layer provided on the main body and through which a first signal is transmitted; a second conductor layer provided on the body, through which a second signal having a higher frequency than the first signal is transmitted; an upper conductor layer that is provided on the main body and is provided above the first conductor layer and the second conductor layer so as to overlap the second conductor layer when viewed in a vertical direction; It is equipped with When viewed in a direction perpendicular to a transmission direction in which the first signal is transmitted, the second conductor layer overlaps the first conductor layer, The thickness of the second conductor layer in the vertical direction is smaller than the thickness of the first conductor layer in the vertical direction, a distance between the upper conductor layer and the second conductor layer is greater than a distance between the upper conductor layer and the first conductor layer; Multilayer board.

15. A laminate having a structure in which a plurality of insulating layers are stacked in the vertical direction; a first conductor layer provided on an upper main surface or a lower main surface of the insulating layer, the first conductor layer transmitting a first signal; a second conductor layer provided on the same principal surface of the insulator layer as the upper principal surface or the lower principal surface of the insulator layer on which the first conductor layer is provided, and through which a second signal having a higher frequency than the first signal is transmitted; an upper conductor layer that is a ground conductor layer and is provided in the laminate and is provided above the first conductor layer and the second conductor layer so as to overlap the second conductor layer when viewed in the up-down direction; It is equipped with The thickness of the second conductor layer in the vertical direction is smaller than the thickness of the first conductor layer in the vertical direction, a distance between the upper conductor layer and the second conductor layer is larger than a distance between the upper conductor layer and the first conductor layer, the plurality of insulator layers include a first insulator layer and a second insulator layer; the first insulating layer and the second insulating layer are laminated below the upper conductor layer and above the first conductor layer and the second conductor layer so as to be adjacent to each other and arranged in this order from top to bottom, the plurality of insulator layers further includes a third insulator layer; the first conductor layer and the second conductor layer are provided on the third insulator layer, the material of the third insulating layer is the same as the material of the first insulating layer; the second insulator layer is an adhesive layer that bonds the first insulator layer and the third insulator layer, The material of the plurality of insulating layers includes a thermoplastic resin, a preparation step of preparing the third insulator layer, the third insulator layer having the first conductor layer and the second conductor layer, which have different thicknesses in the vertical direction, provided on either the upper main surface or the lower main surface; a compression bonding step of stacking the plurality of insulator layers including the third insulator layer in the vertical direction and then subjecting the plurality of insulator layers to a heat treatment and a pressure treatment; Equipped with A method for manufacturing a multilayer board.

16. A laminate having a structure in which a plurality of insulating layers are stacked in the vertical direction; a first conductor layer provided on an upper main surface or a lower main surface of the insulating layer, the first conductor layer transmitting a first signal; a second conductor layer provided on the same principal surface of the insulator layer as the upper principal surface or the lower principal surface of the insulator layer on which the first conductor layer is provided, and through which a second signal having a higher frequency than the first signal is transmitted; an upper conductor layer that is a ground conductor layer and is provided in the laminate and is provided above the first conductor layer and the second conductor layer so as to overlap the second conductor layer when viewed in the up-down direction; It is equipped with The thickness of the second conductor layer in the vertical direction is smaller than the thickness of the first conductor layer in the vertical direction, a distance between the upper conductor layer and the second conductor layer is larger than a distance between the upper conductor layer and the first conductor layer, the plurality of insulator layers include a first insulator layer and a second insulator layer; the first insulating layer and the second insulating layer are laminated below the upper conductor layer and above the first conductor layer and the second conductor layer so as to be adjacent to each other and arranged in this order from top to bottom, the plurality of insulator layers further includes a third insulator layer; the first conductor layer and the second conductor layer are provided on the third insulator layer, the material of the third insulating layer is the same as the material of the first insulating layer; the second insulator layer is an adhesive layer that bonds the first insulator layer and the third insulator layer, a preparation step of preparing the third insulator layer, the third insulator layer having the first conductor layer and the second conductor layer, which have different thicknesses in the vertical direction, provided on either the upper main surface or the lower main surface; a compression bonding process in which the first insulator layer, the second insulator layer which is an adhesive layer not provided with a conductor layer, and the third insulator layer are laminated from top to bottom in this order, and then the first insulator layer, the second insulator layer, and the third insulator layer are subjected to a heat treatment and a pressure treatment; Equipped with A method for manufacturing a multilayer board.

17. The preparation step includes: a conductor foil forming step of forming a conductor foil on the third insulator layer; a plating process for plating a portion of the conductor foil to make the thickness of the first conductor layer in the vertical direction larger than the thickness of the second conductor layer in the vertical direction; Contains The method for manufacturing a multilayer substrate according to claim 15 or 16.

18. The preparation step includes: a conductor foil forming step of forming a conductor foil on the third insulator layer; an etching process for etching a portion of the conductor foil to make the thickness of the second conductor layer smaller than the thickness of the first conductor layer in the vertical direction; Contains The method for manufacturing a multilayer substrate according to claim 15 or 16.

19. In the preparation step, the first conductor layer and the second conductor layer having different thicknesses in the vertical direction are attached to either the upper main surface or the lower main surface of the third insulating layer. The method for manufacturing a multilayer substrate according to claim 15 or 16.

20. The multilayer substrate comprises: an upper conductor layer provided on the laminate and provided above the first conductor layer and the second conductor layer so as to overlap the second conductor layer when viewed in the up-down direction; It is equipped with The thickness of the second conductor layer in the vertical direction is smaller than the thickness of the first conductor layer in the vertical direction. The method for manufacturing a multilayer substrate according to any one of claims 15 to 19.

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