WO-2026094552-A1 - CIRCUIT BOARD

WO2026094552A1WO 2026094552 A1WO2026094552 A1WO 2026094552A1WO-2026094552-A1

Abstract

The present invention provides a circuit board in which conduction between a terminal electrode and a land pattern is less likely to be interrupted even after long-term use. The circuit board comprises: a substrate on which a land electrode is provided; and a coil component mounted on the substrate. The coil component comprises: a core having a winding core part extending in the axial direction and a flange part connected to an end, in the axial direction, of the winding core part and extending at least in a direction intersecting the outer peripheral surface of the winding core part; a coil wound around the outer peripheral surface of the winding core part; and a terminal electrode attached to the flange part. The terminal electrode has an inner surface that faces the flange part, and an outer surface that is the rear surface of the inner surface of the terminal electrode and is joined to the land electrode via a joining material. An end, in the axial direction, of the land electrode on the winding core part side is located closer to the winding core part than is an end, in the axial direction, on the winding core part side of a specific outer surface of the outer surface of the terminal electrode, the specific outer surface facing the land electrode in the intersecting direction.

Inventors

Nishikawa, Shogo
KANBE, YUKI
KOBAYASHI, KOHEI

Assignees

株式会社村田製作所

Dates

Publication Date: 20260507
Application Date: 20251006
Priority Date: 20241028

Claims (7)

A substrate having a mounting surface on which land electrodes are provided, The circuit board comprises a coil component mounted on the mounting surface of the aforementioned substrate, The aforementioned coil component is A core having a winding core portion extending in the axial direction and a flange portion connected to the axial end of the winding core portion and extending in a cross direction that intersects at least the axial direction with respect to the outer circumferential surface of the winding core portion, The coil wound around the outer surface of the aforementioned core portion, The flange portion is attached, electrically connected to the coil, and comprises terminal electrodes made of metal plates, The aforementioned terminal electrodes are The inner surface facing the flange portion, The terminal electrode has an inner surface that is joined to the land electrode via a bonding material, A circuit board in which the axial end of the land electrode on the winding core side is located closer to the winding core than the axial end of a specific outer surface of the terminal electrode that faces the land electrode in the direction intersecting it.
The terminal electrode has a tip side surface that connects the end on the winding core side in the axial direction on a specific outer surface of the terminal electrode to the inner surface of the terminal electrode, The circuit board according to claim 1, wherein the bonding material is in contact with the terminal electrode from a specific outer surface to the tip side surface of the terminal electrode.
A gap is provided in at least a portion of the flange portion between the end face on the land electrode side and the inner surface of the terminal electrode in the intersecting direction. The aforementioned gap opens towards the winding core portion in the axial direction. The circuit board according to claim 1 or 2, wherein the thickness of the bonding material between the land electrode and the specific outer surface of the terminal electrode is greater than or equal to the size of the gap in the intersecting direction.
The circuit board according to any one of claims 1 to 3, wherein the thickness of the bonding material between the land electrode and the specific outer surface of the terminal electrode is half or more of the thickness of the terminal electrode.
The circuit board according to any one of claims 1 to 4, wherein, in the width direction perpendicular to the axial direction and along the mounting surface of the substrate, the outer edge of the land electrode on the winding core side in the axial direction is parallel or substantially parallel to the outer edge of a specific outer surface of the terminal electrode on the winding core side in the axial direction.
The circuit board according to any one of claims 1 to 5, wherein, in the width direction perpendicular to the axial direction and along the mounting surface of the substrate, at least one of the ends of the land electrode is located outside the terminal electrode.
A gap is provided in at least a portion of the flange portion between the end face on the land electrode side and the inner surface of the terminal electrode in the intersecting direction. The aforementioned gap opens towards the winding core portion in the axial direction. The circuit board according to any one of claims 1 to 6, wherein, in the axial direction, the end of the terminal electrode including a specific outer surface on the winding core side is located closer to the winding core than the end of the flange on the winding core side.

Description

Circuit board This disclosure relates to a circuit board comprising a substrate and coil components mounted on the substrate. An example of a circuit board comprising a substrate and coil components mounted on the substrate is disclosed in Patent Document 1. In the circuit board disclosed in Patent Document 1, the coil component comprises a core and terminal electrodes attached to the core. The terminal electrodes are connected to land patterns provided on the surface of the substrate via solder, which acts as a bonding material. A perspective view showing a circuit board according to the first embodiment of this disclosure.A front view showing a circuit board according to the first embodiment of this disclosure.A cross-sectional view showing the section III-III in Figure 1.A bottom view of a coil component according to the first embodiment of this disclosure.A right side view of a coil component according to the first embodiment of this disclosure.An enlarged view of the area enclosed by the dashed line in Figure 3.A cross-sectional view showing the VII-VII section in Figure 2.An enlarged view corresponding to Figure 6 in a circuit board according to the second embodiment of this disclosure.An enlarged view corresponding to Figure 6 in a circuit board according to the third embodiment of this disclosure.An enlarged view corresponding to Figure 6 in the circuit board according to the fourth embodiment of this disclosure.An enlarged view corresponding to Figure 6 in a circuit board according to the fifth embodiment of this disclosure.A right side view of a coil component according to the sixth embodiment of this disclosure. The following description illustrates an example of this disclosure with reference to the accompanying drawings. The following description is essentially illustrative and is not intended to limit this disclosure, its applications, or its uses. Furthermore, the drawings are schematic, and the proportions of dimensions, etc., do not necessarily correspond to reality. In the following description, terms indicating specific directions or positions (e.g., terms including "up," "down," "right," "left," "front," and "back") may be used as needed. In this specification and drawings, the X, Y, and Z directions are defined. The Z direction is the thickness direction of the circuit board, and the X and Y directions are directions intersecting the thickness direction of the circuit board. The X and Y directions intersect each other. In the following embodiments and drawings, the X, Y, and Z directions are orthogonal to each other. The X direction is an example of an axial direction. The Y direction is an example of a width direction. The Z direction is an example of an intersecting direction. The use of the aforementioned terms indicating specific directions or positions is for the purpose of facilitating the understanding of this disclosure with reference to the drawings, and the meaning of those terms does not limit the technical scope of this disclosure. <First Embodiment> Figure 1 is a perspective view showing a circuit board according to the first embodiment of this disclosure. Figure 2 is a front view showing a circuit board according to the first embodiment of this disclosure. Figure 3 is a cross-sectional view showing the section taken along line III-III in Figure 1. Note that the bonding material 3 is not shown in Figure 2. As shown in Figures 1, 2, and 3, the circuit board 1 comprises a substrate 2, a bonding material 3, and a coil component 4. <Circuit board> As shown in Figure 1, the substrate 2 is plate-shaped. The substrate 2 may have a structure consisting of a single insulating layer, or it may have a laminated structure consisting of multiple insulating layers stacked together. If the substrate 2 has a laminated structure, internal electrodes may be provided between each insulating layer. As shown in Figure 3, land electrodes 2B (see Figure 7) are provided on at least one of the front and back surfaces of the substrate 2. In the first embodiment, the land electrodes 2B are provided on the mounting surface 2A, which is one of the front and back surfaces of the substrate 2. More specifically, the land electrodes 2B are provided in recesses formed on the mounting surface 2A. Note that land electrodes 2B may be provided on both the front and back surfaces of the substrate 2. The land electrodes 2B are made of a conductive material such as copper. <Coil components> As shown in Figures 1, 2, and 3, the coil component 4 is mounted on the mounting surface 2A of the substrate 2. As shown in Figures 2 and 3, the coil component 4 comprises a core 10, a coil 20, and terminal electrodes 30. The core 10 has a winding core portion 11 extending in the X direction, a flange portion 12 connected to the X-direction end 111 of the winding core portion 11, and a plate-shaped core 13 placed on the flange portion 12. In the first embodiment, the winding core 11 is rectangular prism-shaped, but it may be ot