US-12620712-B2 - Multilayer board and antenna module

Abstract

A multilayer board includes a multilayer body including a first radiation conductor layer, a ground conductor layer, a first wiring layer, and a second wiring layer. The first wiring layer is electrically connected to a first radiation conductor layer at a first power supply point positioned closest to a first straight line in a first outer edge and intersects but is not orthogonal to the first straight line in a view along a Z-axis direction. The second wiring layer is electrically connected to the first radiation conductor layer at a second power supply point positioned closest to a second straight line in the first outer edge and intersects but is not orthogonal to the second straight line in a view along the Z-axis direction.

Inventors

• Kentarou KAWABE

Assignees

• MURATA MANUFACTURING CO., LTD.

Dates

Publication Date

20260505

Application Date

20230908

Priority Date

20220913

Claims (18)

1. 1 . A multilayer board comprising: a rigid portion; a flexible portion; a multilayer body having a structure in which a plurality of insulator layers are laminated in a Z-axis direction, wherein a length of the flexible portion in the Z-axis direction is shorter than a length of the rigid portion in the Z-axis direction; a first radiation conductor layer provided in the multilayer body and having a first outer edge in a view along the Z-axis direction, the first outer edge including a first straight line and a second straight line; a ground conductor layer provided in the multilayer body, positioned on a negative side of the first radiation conductor layer along a Z axis, and overlapping the first radiation conductor layer in a view along the Z-axis direction; a first wiring layer provided in the multilayer body, positioned on the negative side of the first radiation conductor layer along the Z axis and on a positive side of the ground conductor layer along the Z axis, electrically connected to the first radiation conductor layer at a first power supply point, and intersecting but not orthogonal to the first straight line in a view along the Z-axis direction, the first power supply point being positioned closest to the first straight line in the first outer edge; and a second wiring layer provided in the multilayer body, positioned on the negative side of the first radiation conductor layer along the Z axis and on the positive side of the ground conductor layer along the Z axis, electrically connected to the first radiation conductor layer at a second power supply point, and intersecting but not orthogonal to the second straight line in a view along the Z-axis direction, the second power supply point being positioned closest to the second straight line in the first outer edge.
2. 2 . The multilayer board according to claim 1 , wherein a first region is defined to be a region through which the first straight line passes in a view along the Z-axis direction in a case that the first straight line is moved in a direction orthogonal to the first straight line, the first wiring layer is disposed in both the first region and a region outside the first region in a view along the Z-axis direction, a second region is defined to be a region through which the second straight line passes in a view along the Z-axis direction in a case that the second straight line is moved in a direction orthogonal to the second straight line, and the second wiring layer is disposed in both the second region and a region outside the second region in a view along the Z-axis direction.
3. 3 . The multilayer board according to claim 1 , further comprising: a second radiation conductor layer provided in the multilayer body and having a second outer edge in a view along the Z-axis direction, the second outer edge including a third straight line and a fourth straight line; a third wiring layer provided in the multilayer body, positioned on a negative side of the second radiation conductor layer along the Z axis and on the positive side of the ground conductor layer along the Z axis, electrically connected to the second radiation conductor layer at a third power supply point, and intersecting but not orthogonal to the third straight line in a view along the Z-axis direction, the third power supply point being positioned closest to the third straight line in the second outer edge; and a fourth wiring layer provided in the multilayer body, positioned on the negative side of the second radiation conductor layer along the Z axis and on the positive side of the ground conductor layer along the Z axis, electrically connected to the second radiation conductor layer at a fourth power supply point, and intersecting but not orthogonal to the fourth straight line in a view along the Z-axis direction, the fourth power supply point being positioned closest to the fourth straight line in the second outer edge, wherein the ground conductor layer overlaps the second radiation conductor layer in a view along the Z-axis direction.
4. 4 . The multilayer board according to claim 3 , wherein the second radiation conductor layer is positioned on a positive side of the first radiation conductor layer along an X axis, the X axis is orthogonal to the Z axis, the first straight line and the second straight line are positioned on a positive side of a first part in the first outer edge except for the first straight line and the second straight line along the X axis, and the third straight line and the fourth straight line are positioned on a negative side of a second part in the second outer edge except for the third straight line and the fourth straight line along the X axis.
5. 5 . The multilayer board according to claim 3 , further comprising: a third radiation conductor layer provided in the multilayer body and having a third outer edge in a view along the Z-axis direction, the third outer edge including a fifth straight line and a sixth straight line; a fifth wiring layer provided in the multilayer body, positioned on a negative side of the third radiation conductor layer along the Z axis and on the positive side of the ground conductor layer along the Z axis, electrically connected to the third radiation conductor layer at a fifth power supply point, and intersecting but not orthogonal to the fifth straight line in a view along the Z-axis direction, the fifth power supply point being positioned closest to the fifth straight line in the third outer edge; and a sixth wiring layer provided in the multilayer body, positioned on the negative side of the third radiation conductor layer along the Z axis and on the positive side of the ground conductor layer along the Z axis, electrically connected to the third radiation conductor layer at a sixth power supply point, and intersecting but not orthogonal to the sixth straight line in a view along the Z-axis direction, the sixth power supply point being positioned closest to the sixth straight line in the third outer edge, wherein the ground conductor layer overlaps the third radiation conductor layer in a view along the Z-axis direction.
6. 6 . The multilayer board according to claim 5 , wherein the second radiation conductor layer is positioned on a positive side of the first radiation conductor layer along an X axis, the third radiation conductor layer is positioned on a positive side of the second radiation conductor layer along the X axis, the X axis is orthogonal to the Z axis, the first straight line and the second straight line are positioned on a positive side of a first part in the first outer edge except for the first straight line and the second straight line along the X axis, the third straight line and the fourth straight line are positioned on a negative side of a second part in the second outer edge except for the third straight line and the fourth straight line along the X axis, and the fifth straight line and the sixth straight line are positioned on a positive side of a third part in the third outer edge except for the fifth straight line and the sixth straight line along the X axis.
7. 7 . The multilayer board according to claim 5 , wherein the second radiation conductor layer is positioned on a positive side of the first radiation conductor layer along an X axis, the X axis is orthogonal to the Z axis, a Y axis is orthogonal to the X axis and the Z axis, the third radiation conductor layer is positioned on a positive side of the second radiation conductor layer along the X axis, the first straight line, the third straight line, and the fifth straight line are parallel to the X axis, the second straight line, the fourth straight line, and the sixth straight line overlap one another in a view along an X-axis direction, an end of the first straight line on a positive side along the X axis is connected to an end of the second straight line on a positive side along the Y axis, an end of the third straight line on a positive side along the X axis is connected to an end of the fourth straight line on a positive side along the Y axis, and an end of the fifth straight line on a positive side along the X axis is connected to an end of the sixth straight line on a positive side along the Y axis.
8. 8 . The multilayer board according to claim 5 , wherein the second radiation conductor layer is positioned on a positive side of the first radiation conductor layer along an X axis, the X axis is orthogonal to the Z axis, a Y axis is orthogonal to the X axis and the Z axis, the third radiation conductor layer is positioned on a positive side of the second radiation conductor layer along the X axis, the first straight line, the fourth straight line, and the fifth straight line are parallel to the X axis, the second straight line, the third straight line, and the sixth straight line overlap one another in a view along an X-axis direction, an end of the first straight line on a positive side along the X axis is connected to an end of the second straight line on a positive side along the Y axis, an end of the third straight line on a negative side along the Y axis is connected to an end of the fourth straight line on a negative side along the X axis, and an end of the fifth straight line on a positive side along the X axis is connected to an end of the sixth straight line on a positive side along the Y axis.
9. 9 . The multilayer board according to claim 5 , wherein the second radiation conductor layer is positioned on a positive side of the first radiation conductor layer along an X axis, the X axis is orthogonal to the Z axis, a Y axis is orthogonal to the X axis and the Z axis, the third radiation conductor layer is positioned on a positive side of the second radiation conductor layer along the X axis, the first straight line and the second straight line are positioned on a negative side of a first part in the first outer edge except for the first straight line and the second straight line along the X axis, the third straight line and the fourth straight line are positioned on a negative side of a second part in the second outer edge except for the third straight line and the fourth straight line along the Y axis, and the fifth straight line and the sixth straight line are positioned on a negative side of a third part in the third outer edge except for the fifth straight line and the sixth straight line along the X axis.
10. 10 . The multilayer board according to claim 1 , further comprising: a second radiation conductor layer provided in the multilayer body, positioned on the negative side of the first radiation conductor layer along the Z axis, overlapping the first radiation conductor layer in a view along the Z-axis direction, and having a second outer edge in a view along the Z-axis direction, the second outer edge including a third straight line and a fourth straight line; a third wiring layer provided in the multilayer body, positioned on a negative side of the second radiation conductor layer along the Z axis and on the positive side of the ground conductor layer along the Z axis, electrically connected to the second radiation conductor layer at a third power supply point, and intersecting but not orthogonal to the third straight line in a view along the Z-axis direction, the third power supply point being positioned closest to the third straight line in the second outer edge; and a fourth wiring layer provided in the multilayer body, positioned on the negative side of the second radiation conductor layer along the Z axis and on the positive side of the ground conductor layer along the Z axis, electrically connected to the second radiation conductor layer at a fourth power supply point, and intersecting but not orthogonal to the fourth straight line in a view along the Z-axis direction, the fourth power supply point being positioned closest to the fourth straight line in the second outer edge, wherein the ground conductor layer overlaps the second radiation conductor layer in a view along the Z-axis direction, the first straight line is parallel to the third straight line, the second straight line is parallel to the fourth straight line, an X axis is orthogonal to the Z axis, an end of the first straight line on a positive side along the X axis is connected to an end of the second straight line on a positive side along the X axis, an end of the third straight line on a positive side along the X axis is connected to an end of the fourth straight line on a positive side along the X axis, the first wiring layer intersects but is not orthogonal to the first straight line and the third straight line in a view along the Z-axis direction, and the second wiring layer intersects but is not orthogonal to the second straight line and the fourth straight line in a view along the Z-axis direction.
11. 11 . The multilayer board according to claim 1 , further comprising an annular ground conductor layer provided in the multilayer body and positioned on the positive side of the ground conductor layer along the Z axis, wherein the annular ground conductor layer has an annular shape surrounding the first radiation conductor layer in a view along the Z-axis direction.
12. 12 . The multilayer board according to claim 11 , wherein the first radiation conductor layer includes the first straight line, the second straight line, a seventh straight line, and an eighth straight line in a view along the Z-axis direction and has a rectangular shape in a view along the Z-axis direction, a first distance is defined to be distance from a center of the first straight line to the annular ground conductor layer in a direction orthogonal to the first straight line, a second distance is defined to be distance from a center of the second straight line to the annular ground conductor layer in a direction orthogonal to the second straight line, a third distance is defined to be distance from a center of the seventh straight line to the annular ground conductor layer in a direction orthogonal to the seventh straight line, a fourth distance is defined to be distance from a center of the eighth straight line to the annular ground conductor layer in a direction orthogonal to the eighth straight line, and the first distance, the second distance, the third distance, and the fourth distance are equal to one another.
13. 13 . The multilayer board according to claim 1 , wherein the first wiring layer and the second wiring layer each include a matching portion, and the matching portion does not overlap the first radiation conductor layer in a view along the Z-axis direction.
14. 14 . The multilayer board according to claim 1 , wherein the first wiring layer and the second wiring layer each include a stub portion, and the stub portion does not overlap the first radiation conductor layer in a view along the Z-axis direction.
15. 15 . The multilayer board according to claim 1 , further comprising an annular ground conductor layer provided in the multilayer body and positioned on the positive side of the ground conductor layer along the Z axis, wherein the annular ground conductor layer has an annular shape surrounding the first radiation conductor layer in a view along the Z-axis direction, and no ground conductor is provided between the annular ground conductor layer and the ground conductor layer at the rigid portion.
16. 16 . The multilayer board according to claim 1 , further comprising: a seventh wiring layer provided in the multilayer body, positioned on a negative side of the first wiring layer along the Z axis and on the positive side of the ground conductor layer along the Z axis, and electrically connected to the first wiring layer; and an eighth wiring layer provided in the multilayer body, positioned on a negative side of the second wiring layer along the Z axis and on the positive side of the ground conductor layer along the Z axis, and electrically connected to the second wiring layer.
17. 17 . The multilayer board according to claim 16 , wherein the seventh wiring layer and the eighth wiring layer do not overlap the first radiation conductor layer in a view along the Z-axis direction.
18. 18 . An antenna module comprising: a first substrate that is rigid; and a second substrate that is flexible, wherein the first substrate includes a first multilayer body having a structure in which a plurality of insulator layers are laminated in a Z-axis direction, a first radiation conductor layer provided in the first multilayer body and having a first outer edge in a view along the Z-axis direction, the first outer edge including a first straight line and a second straight line, a first wiring layer provided in the first multilayer body, positioned on a negative side of the first radiation conductor layer along a Z axis, electrically connected to the first radiation conductor layer at a first power supply point, and intersecting but not orthogonal to the first straight line in a view along the Z-axis direction, the first power supply point being positioned closest to the first straight line in the first outer edge, and a second wiring layer provided in the first multilayer body, positioned on the negative side of the first radiation conductor layer along the Z axis, electrically connected to the first radiation conductor layer at a second power supply point, and intersecting but not orthogonal to the second straight line in a view along the Z-axis direction, the second power supply point being positioned closest to the second straight line in the first outer edge, the second substrate includes a second multilayer body having a structure in which a plurality of insulator layers are laminated in the Z-axis direction, a seventh wiring layer provided in the second multilayer body and electrically connected to the first wiring layer, an eighth wiring layer provided in the second multilayer body and electrically connected to the second wiring layer, and a ground conductor layer provided in the second multilayer body, positioned on a negative side of the seventh wiring layer and the eighth wiring layer along the Z axis, and overlapping the first radiation conductor layer, the seventh wiring layer, and the eighth wiring layer in a view along the Z-axis direction, a length of the second substrate in the Z-axis direction is shorter than a length of the first substrate in the Z-axis direction, and the second substrate is positioned on a negative side of the first substrate along the Z axis and has a region not overlapping the first substrate in a view along the Z-axis direction.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS The present application claims priority to Japanese Patent Application No. 2022-145551, filed Sep. 13, 2022, and Japanese Patent Application No. 2023-097403, filed Jun. 14, 2023, the entire contents of each of which are incorporated herein by reference. BACKGROUND 1. Field The present disclosure relates to a multilayer board and an antenna module that include radiation conductor layers. 2. Description of the Related Art An antenna module described in Japanese Unexamined Patent Application Publication No. 2021-83121 is known as an invention related to a conventional multilayer board. The antenna module includes a radiation conductor layer, a first power supply point, and a second power supply point. A first high-frequency signal is input to the radiation conductor layer through the first power supply point. The radiation conductor layer radiates the first high-frequency signal. A second high-frequency signal is input to the radiation conductor layer through the second power supply point. The radiation conductor layer radiates the second high-frequency signal. The direction of polarized waves of the first high-frequency signal is different from the direction of polarized waves of the second high-frequency signal. SUMMARY As recognized by the inventor, in the field of the antenna module described in Japanese Unexamined Patent Application Publication No. 2021-83121, it is required to reduce the difference between the radiation pattern of the first high-frequency signal and the radiation pattern of the second high-frequency signal and prevent tilt of the radiation direction of the first high-frequency signal and the radiation direction of the second high-frequency signal with respect to the normal direction of the principal surfaces of the radiation conductor layer. Thus, the present disclosure is intended to provide a multilayer board and an antenna module that are capable of reducing the difference between the radiation pattern of the first high-frequency signal and the radiation pattern of the second high-frequency signal and preventing tilt of the radiation direction of the first high-frequency signal and the radiation direction of the second high-frequency signal with respect to the normal direction of the principal surfaces of the radiation conductor layer. A multilayer board according to an embodiment of the present disclosure includes: a multilayer body having a structure in which a plurality of insulator layers are laminated in a Z-axis direction; a first radiation conductor layer provided in the multilayer body and having a first outer edge in a view along the Z-axis direction, the first outer edge including a first straight line and a second straight line; a ground conductor layer provided in the multilayer body, positioned on a negative side of the first radiation conductor layer along a Z axis, and overlapping the first radiation conductor layer in a view along the Z-axis direction; a first wiring layer provided in the multilayer body, positioned on the negative side of the first radiation conductor layer along the Z axis and on a positive side of the ground conductor layer along the Z axis, electrically connected to the first radiation conductor layer at a first power supply point, and intersecting but not orthogonal to the first straight line in a view along the Z-axis direction, the first power supply point being positioned closest to the first straight line in the first outer edge; and a second wiring layer provided in the multilayer body, positioned on the negative side of the first radiation conductor layer along the Z axis and on the positive side of the ground conductor layer along the Z axis, electrically connected to the first radiation conductor layer at a second power supply point, and intersecting but not orthogonal to the second straight line in a view along the Z-axis direction, the second power supply point being positioned closest to the second straight line in the first outer edge. An antenna module according to an embodiment of the present disclosure includes: a first substrate; and a second substrate that is flexible, in which the first substrate includes a first multilayer body having a structure in which a plurality of insulator layers are laminated in a Z-axis direction, a first radiation conductor layer provided in the first multilayer body and having a first outer edge in a view along the Z-axis direction, the first outer edge including a first straight line and a second straight line, a first wiring layer provided in the first multilayer body, positioned on a negative side of the first radiation conductor layer along a Z axis, electrically connected to the first radiation conductor layer at a first power supply point, and intersecting but not orthogonal to the first straight line in a view along the Z-axis direction, the first power supply point being positioned closest to the first straight line in the first outer edge, and a second