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US-12617182-B2 - Multilayer substrate

US12617182B2US 12617182 B2US12617182 B2US 12617182B2US-12617182-B2

Abstract

In a multilayer substrate, a second multilayer body is positioned in a positive direction of a Z-axis of a first multilayer body. The second multilayer body is fixed to the first multilayer body via a first insulator layer bonded to a second insulator layer. Regions obtained by dividing the first multilayer body into three equal portions in the Z-axis direction are defined as a positive region, an intermediate region, and a negative region. A portion of one or more positive region first conductor layers is located in the positive region. An entirety of one or more intermediate region first conductor layers is located in the intermediate region. A thickness in the Z-axis direction of at least one of the one or more positive region first conductor layers is larger than the thickness in the Z-axis direction of the one or more intermediate region first conductor layers.

Inventors

  • Nobuo IKEMOTO
  • Keiichi Ichikawa
  • Kentarou KAWABE

Assignees

  • MURATA MANUFACTURING CO., LTD.

Dates

Publication Date
20260505
Application Date
20240918
Priority Date
20220609

Claims (17)

  1. 1 . A multilayer substrate comprising: a first multilayer body including a plurality of first insulator layers stacked in a Z-axis direction; a second multilayer body including a plurality of second insulator layers stacked in the Z-axis direction; and a plurality of first conductor layers in the first multilayer body; wherein the second multilayer body is positioned in a positive direction of a Z-axis of the first multilayer body; the second multilayer body is fixed to the first multilayer body via the first insulator layer being bonded to the second insulator layer; a first region in which the first multilayer body and the second multilayer body are provided when viewed in the Z-axis direction and a second region in which the first multilayer body is provided and the second multilayer body is not provided when viewed in the Z-axis direction are provided; regions obtained by dividing the first multilayer body into three equal or substantially equal portions in the Z-axis direction are defined as a positive region, an intermediate region, and a negative region; the positive region, the intermediate region, and the negative region are arranged in this order toward a negative direction of the Z-axis; the plurality of first conductor layers include one or more positive region first conductor layers and one or more intermediate region first conductor layers; at least a portion of each of the one or more positive region first conductor layers is located in the positive region; an entirety or substantially an entirety of each of the one or more intermediate region first conductor layers is located in the intermediate region; and a thickness in the Z-axis direction of at least one of the one or more positive region first conductor layers is larger than a thickness in the Z-axis direction of the one or more intermediate region first conductor layers.
  2. 2 . The multilayer substrate according to claim 1 , wherein the plurality of first insulator layers include a first insulator layer on a most positive side positioned farthest in the positive direction of the Z-axis among the plurality of first insulator layers in the first multilayer body; the plurality of first conductor layers include a negative-side adjacent first conductor layer, the negative-side adjacent first conductor layer being in contact with a main surface of the first insulator layer on the most positive side, the main surface being positioned in the negative direction of the Z-axis; and a thickness in the Z-axis direction of a portion of the first insulator layer on the most positive side that is in contact with the negative-side adjacent first conductor layer is smaller than a thickness in the Z-axis direction of the negative-side adjacent first conductor layer.
  3. 3 . The multilayer substrate according to claim 1 , wherein the plurality of first conductor layers include a first conductor layer on a most positive side positioned farthest in the positive direction of the Z-axis among the conductor layers in the first multilayer body; and a thickness in the Z-axis direction of the first conductor layer on the most positive side is larger than a thickness in the Z-axis direction of the one or more intermediate region first conductor layers.
  4. 4 . The multilayer substrate according to claim 1 , wherein each of the plurality of first conductor layers includes a first main surface and a second main surface with a surface roughness larger than a surface roughness of the first main surface; and the second main surface of each of the plurality of first conductor layers is in contact with a respective one of the plurality of first insulator layers.
  5. 5 . The multilayer substrate according to claim 4 , further comprising: a protection layer covering a surface of the first multilayer body positioned in the negative direction of the Z-axis; wherein the second main surface of the first conductor layer is not in contact with the protection layer.
  6. 6 . The multilayer substrate according to claim 1 , wherein one of the plurality of first conductor layers is located on a main surface of the first insulator layer positioned farthest in the positive direction of the Z-axis among the plurality of first insulator layers, the main surface being positioned in the positive direction of the Z-axis; and another one of the plurality of first conductor layers is located on a main surface of the first insulator layer positioned farthest in the negative direction of the Z-axis among the plurality of first insulator layers, the main surface being positioned in the negative direction of the Z-axis.
  7. 7 . The multilayer substrate according to claim 1 , wherein the plurality of first conductor layers include one or more negative region first conductor layers; at least a portion of each of the one or more negative region first conductor layers is located in the negative region; and a thickness in the Z-axis direction of at least one of the one or more negative region first conductor layers is larger than a thickness in the Z-axis direction of the one or more intermediate region first conductor layers.
  8. 8 . The multilayer substrate according to claim 1 , wherein at least one of the one or more positive region first conductor layers overlaps a boundary between the first region and the second region when viewed in the Z-axis direction.
  9. 9 . The multilayer substrate according to claim 1 , further comprising: a plurality of second conductor layers provided in the second multilayer body; wherein a thickness in the Z-axis direction of the second conductor layers located at both ends in the Z-axis direction among the plurality of second conductor layers is larger than a thickness in the Z-axis direction of remaining ones of the second conductor layers.
  10. 10 . The multilayer substrate according to claim 9 , wherein the plurality of second conductor layers define at least one coil.
  11. 11 . The multilayer substrate according to claim 9 , wherein each of the plurality of second conductor layers includes a copper foil.
  12. 12 . The multilayer substrate according to claim 1 , wherein a thickness of the first multilayer body in the Z-axis direction is smaller than a thickness of the second multilayer body in the Z-axis direction.
  13. 13 . The multilayer substrate according to claim 1 , wherein each of the plurality of first conductor layers includes a copper foil.
  14. 14 . The multilayer substrate according to claim 1 , wherein a protection layer covers a lower surface of the first multilayer body.
  15. 15 . The multilayer substrate according to claim 14 , wherein a material of the protection layer is different from a material of the plurality of first insulator layers.
  16. 16 . The multilayer substrate according to claim 1 , wherein each of the plurality of second insulator layers includes a thermoplastic resin.
  17. 17 . The multilayer substrate according to claim 16 , wherein the thermoplastic resin is a liquid crystal polymer.

Description

CROSS REFERENCE TO RELATED APPLICATIONS This application claims the benefit of priority to Japanese Patent Application No. 2022-093630 filed on Jun. 9, 2022 and is a Continuation Application of PCT Application No. PCT/JP2023/017214 filed on May 6, 2023. The entire contents of each application are hereby incorporated herein by reference. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to multilayer substrates including insulator layers that are stacked. 2. Description of the Related Art As an invention related to an existing multilayer substrate, for example, a laminated substrate described in Japanese Unexamined Patent Application Publication No. 2006-19643 has been known. The laminated substrate has a structure in which a plurality of dielectric layers are laminated in an up-down direction. A cavity for mounting an electronic component is provided on the upper surface of the laminated substrate. In the laminated substrate described in Japanese Unexamined Patent Application Publication No. 2006-19643, the thickness in the up-down direction of the portion of the laminated substrate in which the cavity is provided is smaller than the thickness in the up-down direction of the portion of the laminated substrate in which the cavity is not provided. Therefore, the strength of the portion of the laminated substrate in which the cavity is provided is low. As a result, in a thermal pressure bonding process of the laminated substrate, the laminated substrate may be deformed, and the cavity may be deformed. In this case, a short circuit may occur between the conductors provided in the vicinity of the cavity. SUMMARY OF THE INVENTION Example embodiments of the present invention reduce or prevent short circuiting in a multilayer substrate in which a second multilayer body is fixed on a first multilayer body. A multilayer substrate according to an example embodiment of the present invention includes a first multilayer body including a plurality of first insulator layers that are stacked in a Z-axis direction, a second multilayer body including a plurality of second insulator layers that are stacked in the Z-axis direction; and a plurality of first conductor layers in the first multilayer body. The second multilayer body is positioned in a positive direction of a Z-axis of the first multilayer body. The second multilayer body is fixed to the first multilayer body by bonding one of the plurality of first insulator layers to one of the plurality of second insulator layers. A first region in which the first multilayer body and the second multilayer body are provided when viewed in the Z-axis direction and a second region in which the first multilayer body is provided and the second multilayer body is not provided when viewed in the Z-axis direction are provided. Regions obtained by dividing the first multilayer body into three equal portions in the Z-axis direction are defined as a positive region, an intermediate region, and a negative region. The positive region, the intermediate region, and the negative region are arranged in this order toward a negative direction of the Z-axis. The plurality of first conductor layers include one or more positive region first conductor layers and one or more intermediate region first conductor layers. At least a portion of each of the one or more positive region first conductor layers is located in the positive region. An entirety or substantially an entirety of each of the one or more intermediate region first conductor layers is located in the intermediate region. A thickness in the Z-axis direction of at least one of the one or more positive region first conductor layers is larger than a thickness in the Z-axis direction of the one or more intermediate region first conductor layers. According to example embodiments of the present invention, short circuiting is reduced or prevented in a multilayer substrate in which a second multilayer body is fixed on a first multilayer body. The above and other elements, features, steps, characteristics and advantages of the present invention will become more apparent from the following detailed description of the example embodiments with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view of a multilayer substrate 10 according to an example embodiment of the present invention. FIG. 2 is a top view of the multilayer substrate 10 according to an example embodiment of the present invention. FIG. 3 is a top view of a multilayer substrate 10a according to an example embodiment of the present invention. FIG. 4 is a top view of a multilayer substrate 10b according to an example embodiment of the present invention. FIG. 5 is a top view of a multilayer substrate 10c according to an example embodiment of the present invention. FIG. 6 is a top view of a multilayer substrate 10d according to an example embodiment of the present invention. FIG. 7 is a cross-sectional view of a