US-20260129753-A1 - PRINTED CIRCUIT BOARD

Abstract

A printed circuit board includes a first insulating layer including a protrusion portion, and a metal layer disposed on the protrusion portion of the first insulating layer. A width of a lowermost portion of the protrusion portion is greater than a width of an uppermost portion of the protrusion portion.

Inventors

• Chan Jin Park
• Hyun Seok Yang
• Myong Keun Jung
• Eun Su KWON

Assignees

• SAMSUNG ELECTRO-MECHANICS CO., LTD.

Dates

Publication Date

20260507

Application Date

20250813

Priority Date

20241106

Claims (20)

1. 1 . A printed circuit board comprising: a first insulating layer including a protrusion portion; and a metal layer disposed on the protrusion portion of the first insulating layer, wherein a width of a first end portion of the protrusion portion is greater than a width of a second end portion of the protrusion portion.
2. 2 . The printed circuit board of claim 1 , wherein a width of the protrusion portion gradually increases from the second end portion to the first end portion.
3. 3 . The printed circuit board of claim 1 , wherein a width of a first end portion of the metal layer is greater than a width of a second end portion of the metal layer.
4. 4 . The printed circuit board of claim 1 , wherein a width of the metal layer gradually increases from a second end portion of the metal layer to a first end portion of the metal layer.
5. 5 . The printed circuit board of claim 1 , wherein a width of a first end portion of the metal layer is less than the width of the first end portion of the protrusion portion.
6. 6 . The printed circuit board of claim 1 , wherein a width of a first end portion of the metal layer and the width of the second end portion of the protrusion portion are equal to each other.
7. 7 . The printed circuit board of claim 1 , wherein a side surface of the metal layer and a side surface of the protrusion portion are coplanar with each other in at least a portion of a region in which the metal layer and the protrusion portion are connected to each other.
8. 8 . The printed circuit board of claim 7 , wherein a width of the metal layer gradually increases from a second end portion of the metal layer to a first end portion of the metal layer, and the width of the protrusion portion gradually increases from the second end portion of the protrusion portion to the first end portion of the protrusion portion.
9. 9 . The printed circuit board of claim 1 , wherein the metal layer includes a seed layer and a plating layer disposed on the seed layer.
10. 10 . The printed circuit board of claim 9 , wherein a width of a first end portion of the seed layer is greater than a width of a first end portion of the plating layer.
11. 11 . The printed circuit board of claim 9 , wherein the seed layer does not extend to a region of the first insulating layer beyond the protrusion portion.
12. 12 . The printed circuit board of claim 1 , wherein the first insulating layer includes a plurality of protrusion portions, and a width of a first end portion of the metal layer is greater than a distance between adjacent protrusion portions among the plurality of protrusion portions.
13. 13 . The printed circuit board of claim 12 , wherein a width of a second end portion of the metal layer is greater than the distance between the adjacent protrusion portions among the plurality of protrusion portions.
14. 14 . The printed circuit board of claim 12 , wherein the width of the first end portion of the protrusion portion is greater than the distance between the adjacent protrusion portions among the plurality of protrusion portions.
15. 15 . The printed circuit board of claim 1 , wherein widths of a second end portion and a first end portion of the metal layer are equal to each other.
16. 16 . The printed circuit board of claim 1 , wherein an end surface of a second end portion of the metal layer includes a curved surface.
17. 17 . The printed circuit board of claim 1 , wherein an end surface of a second end portion of the metal layer has a pointed shape.
18. 18 . The printed circuit board of claim 9 , wherein the seed layer includes copper.
19. 19 . The printed circuit board of claim 1 , wherein at least a portion of a side surface of the metal layer and at least a portion of a side surface of the protrusion portion are inclined at the same angle with respect to a plane that is perpendicular to a direction in which the protrusion portion and the metal layer are stacked.
20. 20 . The printed circuit board of claim 16 , wherein the curved surface includes an apex of the metal layer.

Description

CROSS-REFERENCE TO RELATED APPLICATION(S) This application claims benefit of priority to Korean Patent Application No. 10-2024-0155827 filed on Nov. 6, 2024 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference in its entirety. TECHNICAL FIELD The present disclosure relates to a printed circuit board. In response to the recent trend of miniaturization and weight reductions in mobile devices, there is an increasing need to achieve miniaturization and weight reduction in printed circuit boards (PCBs) mounted in such devices. As mobile devices have reduced weights and sizes, an undercut phenomenon may occur during the fabrication of microcircuits, which may lead to defects in the circuits. To meet such technical demands, research has been continuously conducted to improve the reliability of microcircuits while implementing circuits with reduced linewidths and distances therebetween. SUMMARY An aspect of the present disclosure provides a printed circuit board including a fine metal layer having high reliability. According to an aspect of the present disclosure, there is provided a printed circuit board including a first insulating layer including a protrusion portion, and a metal layer disposed on the protrusion portion of the first insulating layer. A width of a first end portion of the protrusion portion may be greater than a width of a second end portion of the protrusion portion. A width of the protrusion portion may gradually increase from the second end portion to the first end portion. A width of a first end portion of the metal layer may be greater than a width of a second end portion of the metal layer. A width of the metal layer may gradually increase from a second end portion of the metal layer to a first end portion of the metal layer. A width of a first end portion of the metal layer may be less than the width of the first end portion of the protrusion portion. A width of a first end portion of the metal layer and the width of the second end portion of the protrusion portion may be equal to each other. A side surface of the metal layer and a side surface of the protrusion portion may be coplanar with each other in at least a portion of a region in which the metal layer and the protrusion portion are connected to each other. A width of the metal layer may gradually increase from a second end portion of the metal layer to a first end portion of the metal layer, and the width of the protrusion portion may gradually increase from the second end portion of the protrusion portion to the first end portion of the protrusion portion. The metal layer may include a seed layer and a plating layer disposed on the seed layer. A width of a first end portion of the seed layer may be greater than a width of a first end portion of the plating layer. The seed layer may not extend to a region of the first insulating layer beyond the protrusion portion. The first insulating layer may include a plurality of protrusion portions. A width of a first end portion of the metal layer may be greater than a distance between adjacent protrusion portions among the plurality of protrusion portions. A width of a second end portion of the metal layer may be greater than the distance between the adjacent protrusion portions among the plurality of protrusion portions. The width of the first end portion of the protrusion portion may be greater than the distance between the adjacent protrusion portions among the plurality of protrusion portions. Widths of a second end portion and a first end portion of the metal layer may be equal to each other. An end surface of a second end portion of the metal layer may include a curved surface. An end surface of a second end portion of the metal layer may have a pointed shape. The seed layer may include copper. At least a portion of a side surface of the metal layer and at least a portion of a side surface of the protrusion portion may be inclined at the same angle with respect to a plane that is perpendicular to a direction in which the protrusion portion and the metal layer are stacked. The curved surface may include an apex of the metal layer. According to example embodiments of the present disclosure, a printed circuit board may include a fine metal layer having high reliability. BRIEF DESCRIPTION OF DRAWINGS The above and other aspects, features, and advantages of the present disclosure will be more clearly understood from the following detailed description, taken in conjunction with the accompanying drawings, in which: FIG. 1 is a schematic block diagram illustrating an example of an electronic device system; FIG. 2 is a schematic perspective view of an example of an electronic device; FIG. 3 is a schematic cross-sectional view of an example of a printed circuit board; FIG. 4 is a schematic plan view of a metal layer disposed on a protrusion portion of a first insulating layer; FIG. 5 is a schematic cross-sectional view of another example of a p