Printed circuit board and manufacturing method thereof

Abstract

The invention provides a printed circuit board and a method of manufacturing the same. A printed circuit board according to an embodiment includes: a first insulating layer; a pad portion disposed on the first insulating layer; a connection portion disposed on the pad portion and including a protruding portion and a first recessed portion disposed within the protruding portion; and a second insulating layer disposed on the pad portion and exposing a portion of the connection portion, in which a height of the first recess of the connection portion measured from an upper surface of the first insulating layer is higher than a height of a first portion of the second insulating layer adjacent to the connection portion, the height of the first portion of the second insulating layer is a height measured from the upper surface of the first insulating layer to an upper surface of the first portion of the second insulating layer.

Description

Technical Field

[0001] The present disclosure relates to a printed circuit board and a method for manufacturing the same. Background Art

[0002] As electronic devices in the IT field, including mobile phones, become smaller, the size of metal posts formed on a printed circuit board on which electronic components are mounted also becomes smaller.

[0003] As the size of the metal pillars of the printed circuit board decreases, adhesion between the metal pillars of the printed circuit board and the semiconductor chip mounted on the printed circuit board may decrease. Summary of the invention

[0004] The present disclosure is to provide a printed circuit board capable of improving contact characteristics of a connection portion connected to a pad portion of the printed circuit board and a method of manufacturing the same.

[0005] However, the embodiments of the present disclosure are not limited to the embodiments described in the detailed description and can be variously extended within the scope of the technical ideas included in the present disclosure.

[0006] According to an embodiment, a printed circuit board includes: a first insulating layer; a pad portion, which is arranged on the first insulating layer; a connecting portion, which is arranged on the pad portion and includes a protrusion and a first recessed portion arranged in the protrusion; and a second insulating layer, which is arranged on the pad portion and exposes a portion of the connecting portion, wherein a height of the first recessed portion of the connecting portion measured from the upper surface of the first insulating layer is higher than a height of a first portion of the second insulating layer adjacent to the connecting portion, and the height of the first portion of the second insulating layer is a height measured from the upper surface of the first insulating layer to the upper surface of the first portion of the second insulating layer.

[0007] The first recess of the connection portion may be positioned above the first portion of the second insulating layer.

[0008] The connection portion may further include a second recessed portion provided along an edge of the protruding portion.

[0009] The protrusion may surround the first recess, and the second recess may surround the protrusion.

[0010] A height of the second recess measured from the upper surface of the first insulating layer may be higher than a height of the first portion of the second insulating layer.

[0011] An outer planar shape of the protrusion of the connection portion and an outer planar shape of the first recess may be substantially the same.

[0012] The outer planar shape of the protrusion of the connection portion and the outer planar shape of the first recess may be substantially circular.

[0013] An outer planar shape of the protrusion of the connection portion and an outer planar shape of the first recess may be different from each other.

[0014] The outer planar shape of the protrusion of the connection portion may be substantially circular, and the outer planar shape of the first recess may be polygonal.

[0015] The outer planar shape of the protrusion of the connection portion may be substantially circular, and the outer planar shape of the first recess may be elliptical.

[0016] The height of the first recess may decrease from the protruding portion toward a center of the connecting portion.

[0017] The height of the first recess may be a height measured from the upper surface of the first insulating layer to a lowest point of the first recess.

[0018] According to an embodiment, a method for manufacturing a printed circuit board includes: forming a pad portion on a first insulating layer; forming a first photosensitive film having a first hole overlapping the pad portion on the pad portion; forming a metal layer in the first hole of the first photosensitive film; forming a second photosensitive film having a second hole overlapping a portion of the metal layer; and processing the metal layer to form a connecting portion, the connecting portion including a protrusion and a first recess arranged in the protrusion.

[0019] The second photosensitive film may be formed after removing the first photosensitive film.

[0020] The second hole of the second photosensitive film may correspond to the protrusion of the connection part.

[0021] In the step of processing the metal layer, another metal layer may be formed on the metal layer to fill the second hole.

[0022] The connection portion may be formed to further include a second recessed portion provided along an edge of the protruding portion, and the second hole of the second photosensitive film may be formed not to overlap the second recessed portion.

[0023] The second photosensitive film may be formed on the first photosensitive film, and a width of the second hole of the second photosensitive film may be narrower than a width of the first hole of the first photosensitive film.

[0024] In the step of processing the metal layer, a portion of the metal layer exposed by the second hole in the second photosensitive film may be etched to form the first recess.

[0025] According to the embodiments, a printed circuit board capable of improving a contact characteristic of a connection portion connected to a pad portion of the printed circuit board and a method of manufacturing the same may be provided.

[0026] However, the embodiments of the present disclosure are not limited to the embodiments described in the detailed description and can be variously extended within the scope of the technical ideas included in the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is a simplified cross-sectional view of a printed circuit board according to an embodiment.

[0028] Figure 2 yes Figure 1 A top view of a portion of the floor plan.

[0029] Figure 3 yes Figure 1 A top view of a portion of the floor plan.

[0030] Figure 4 yes Figure 1 A top view of a portion of the floor plan.

[0031] Figures 5 to 13 is a simplified cross-sectional view illustrating a method of manufacturing a printed circuit board according to an embodiment.

[0032] Fig.14 is a simplified cross-sectional view of a printed circuit board according to another embodiment.

[0033] Fig.15 yes Fig.14 A top view of a portion of the floor plan.

[0034] Fig.16 yes Fig.14 A top view of a portion of the floor plan.

[0035] Fig.17 yes Fig.14 A top view of a portion of the floor plan.

[0036] Figures 18 to 25 is a simplified cross-sectional view illustrating a method of manufacturing a printed circuit board according to another embodiment. DETAILED DESCRIPTION

[0037] Hereinafter, the present disclosure will be described in detail with reference to the accompanying drawings, in which embodiments of the present disclosure are shown. As will be appreciated by those skilled in the art, the described embodiments may be modified in various different ways, all of which do not depart from the spirit or scope of the present disclosure.

[0038] The drawings and description are to be regarded as illustrative in nature and not restrictive.Throughout the specification, like reference numerals refer to like elements.

[0039] The drawings are only intended to facilitate understanding of the embodiments disclosed in this specification, and it will be understood that the technical ideas disclosed herein are not limited to the drawings and include all modifications, equivalents or replacements within the scope of the ideas and technologies of the present disclosure.

[0040] For better understanding and ease of description, the size (eg, thickness) of each component in the drawings is arbitrarily shown. In the drawings, the sizes of layers, films, panels, regions, etc. are exaggerated for clarity.

[0041] It will be understood that when an element such as a layer, film, region, or substrate is referred to as being "on" another element, the element may be directly on the other element, or intervening elements may also be present. In contrast, when an element is referred to as being "directly on" another element, there are no intervening elements. In addition, when an element is referred to as being "on" or "above" a reference element, the element may be positioned above or below the reference element, and is not necessarily positioned "on" or "above" the reference element in a direction opposite to the direction of gravity.

[0042] In addition, unless explicitly described to the contrary, the words “comprises,” “comprising,” or “having,” etc., will be understood to imply the inclusion of stated elements but not the exclusion of any other elements.

[0043] Furthermore, the term “top plan view” means a view obtained by observing an object from a position above the object (e.g., from the top), and the term “cross-sectional view” means a view obtained by observing an object from the side, or a view obtained by vertically cutting the object.

[0044] Throughout the specification, the term "connected" not only means that two or more constituent components are directly connected, but may also mean that two or more constituent components are indirectly connected through another constituent component, that two or more constituent components are electrically connected and physically connected, or that two or more constituent components are connected although they are referred to by different names according to positions or functions.

[0045] Hereinafter, various embodiments and modifications will be described in detail with reference to the accompanying drawings.

[0046] Reference Figure 1 as well as Figures 2 to 4 , a printed circuit board according to an embodiment will be described. Figure 1 is a simplified cross-sectional view of a printed circuit board according to an embodiment, and Figures 2 to 4 yes Figure 1 A top view of a portion of the floor plan.

[0047] Reference Figure 1According to the embodiment, the printed circuit board may include a first insulating layer SUB, a pad portion ML disposed on the first insulating layer SUB, a connecting portion SB disposed on the pad portion ML, and a second insulating layer CL covering a portion of the pad portion ML and a portion of the connecting portion SB.

[0048] The connection portion SB may include a protrusion SBP, a first recess SBC located inside the protrusion SBP, and a second recess SBE located outside the protrusion SBP. For example, the protrusion SBP may surround the first recess SBC, and the second recess SBE may surround the protrusion SBP.

[0049] The connection portion SB may protrude over the second insulating layer CL and be connected to an external device.

[0050] The upper surfaces of the first recess SBC and the second recess SBE and the protrusion SBP of the connection portion SB may be positioned above the upper surface of the first portion of the second insulating layer CL. In the present disclosure, unless otherwise described, the first portion of the second insulating layer CL may refer to a portion of the second insulating layer CL adjacent to the connection portion SB, excluding the protrusion CLP (described below) of the second insulating layer CL.

[0051] A height Ha of the first and second recesses SBC and SBE of the connection portion SB measured from the upper surface of the first insulation layer SUB may be higher than a height Hb of the first portion of the second insulation layer CL measured from the upper surface of the first insulation layer SUB.

[0052] In this way, the first recess SBC and the second recess SBE of the connection portion SB may be positioned above the first portion of the second insulating layer CL, so that the height Ha of the first recess SBC and the second recess SBE of the connection portion SB measured from the upper surface of the first insulating layer SUB is higher than the height Hb of the first portion of the second insulating layer CL measured from the upper surface of the first insulating layer SUB. Therefore, during the manufacturing process, a portion of the insulating layer CL1 (described below) may be removed so that the second insulating layer CL does not remain on the first recess SBC and the second recess SBE of the connection portion SB. In some embodiments, the first recess SBC and / or the second recess SBE are completely disposed above the upper surface of the first portion of the second insulating layer CL. For example, the first recess SBC and the second recess SBE are positioned outside the second insulating layer CL and do not extend into the second insulating layer CL.

[0053] A lower surface of the connection portion SB may contact the pad portion ML to electrically connect the printed circuit board to an external device.

[0054] The second insulating layer CL may further include an upward protrusion CLP, but the protrusion CLP may be omitted.

[0055] The second insulating layer CL may include a solder resist, but the embodiment is not limited thereto.

[0056] Although not shown, the pad portion ML may be connected to an additional wiring layer disposed under or embedded in the first insulating layer SUB through a via hole formed in the first insulating layer SUB.

[0057] Reference Figure 1 and Figure 2 , an outer planar shape formed by an edge of the protrusion SBP of the connection part SB of the printed circuit board according to the embodiment may be substantially the same as an outer planar shape formed by an edge of the first recess SBC and an outer planar shape formed by an edge of the second recess SBE.

[0058] The outer plane shape of the protrusion SBP of the connecting portion SB, the outer plane shape of the first recess SBC, and the outer plane shape of the second recess SBE may have a substantially circular plane shape. In other embodiments, the outer plane shape of the protrusion SBP of the connecting portion SB, the outer plane shape of the first recess SBC, and the outer plane shape of the second recess SBE may be substantially elliptical.

[0059] Reference Figure 3 , although the outer edge of the protrusion SBP of the connecting portion SB of the printed circuit board according to the embodiment may have a substantially circular outer planar shape, the first recess SBC may have a square outer planar shape, and the second recess SBE of the connecting portion SB may have a substantially circular outer planar shape.

[0060] Reference Figure 4 , although the outer edge of the protrusion SBP of the connecting portion SB of the printed circuit board according to the embodiment may have a substantially circular outer planar shape, the first recess SBC may have an elliptical outer planar shape, and the second recess SBE of the connecting portion SB may have a substantially circular outer planar shape.

[0061] The outer planar shapes of the protruding portion SBP, the first recessed portion SBC, and the second recessed portion SBE of the connecting portion SB may be changed in various ways.

[0062] The connection portion of the printed circuit board according to the embodiment may include an upward protrusion SBP, a first recess SBC located inside the protrusion SBP, and a second recess SBE located outside the protrusion SBP. Compared with a conventional connection portion in the form of a single column that does not include any recess, the surface area provided by the connection portion SB of the present disclosure (on which connection can be made) can be larger.

[0063] According to the embodiments described herein, the surface area of ​​the portion of the connection portion SB positioned above the upper surface of the first portion of the second insulating layer CL can be increased, so that the contact area between the external device and the connection portion SB can be relatively larger. In addition, the adhesion between the external device and the connection portion SB can be increased by reducing the shear stress between the external device and the connection portion SB, and the contact resistance between the external device and the connection portion SB can be reduced to reduce the loss of the electrical signal and reduce the resistance.

[0064] Reference Figures 5 to 13 as well as Figures 1 to 4 , a method of manufacturing a printed circuit board according to an embodiment will be described. Figures 5 to 13 is a simplified cross-sectional view illustrating a method of manufacturing a printed circuit board according to an embodiment.

[0065] Reference Figure 5 , a pad portion ML may be formed on the first insulating layer SUB. Figure 6 , a first photosensitive film DF1 may be formed (eg, stacked) on the pad portion ML.

[0066] The first photosensitive film DF1 may be photosensitive and may be a dry film, but the embodiment is not limited thereto.

[0067] like Figure 7 As shown in FIG. 1 , a first hole HL1 at least partially overlapping the pad portion ML may be formed in the first photosensitive film DF1 .

[0068] The protrusion SBP, the first concave portion SBC, and the second concave portion SBE of the connection portion SB may be disposed in the first hole HL1 of the first photosensitive film DF1.

[0069] Reference Figure 8 , a metal layer may be formed in the first hole HL1 of the first photosensitive film DF1 to form the first portion SB1 of the connecting portion SB.

[0070] Reference Fig. 9 , the first photosensitive film DF1 may be removed, and the second photosensitive film DF2 may be stacked on the first portion SB1 of the connection portion SB.

[0071] Reference Fig.10 , a second hole HL2 may be formed in the second photosensitive film DF2. The second hole HL2 may be formed in a region of the second photosensitive film DF2 where the protrusion SBP of the connection part SB is to be formed, and a planar shape of the second hole HL2 may be the same as a planar shape of the protrusion SBP of the connection part SB. That is, the second hole HL2 of the second photosensitive film DF2 may be formed to correspond to the protrusion SBP of the connection part SB. In some embodiments, the second hole HL2 may have a shape defined by two concentric circles.

[0072] exist Fig.10The middle portion of the first part SB1 of the connection part SB not overlapping the second hole HL2 of the second photosensitive film DF2 may correspond to the first concave portion SBC of the connection part SB. The edge portion of the second photosensitive film DF2 not overlapping the second hole HL2 may correspond to the second concave portion SBE of the connection part SB.

[0073] Reference Fig.11 A metal layer may be formed (eg, deposited) on a portion of the first portion SB1 of the connection portion SB overlapping the second hole HL2 of the second photosensitive film DF2 to form a protrusion SBP of the connection portion SB disposed in the second hole HL2 of the second photosensitive film DF2.

[0074] Reference Fig.12 , the second photosensitive film DF2 may be removed. Thus, a connection portion SB including a protruding portion SBP, a first concave portion SBC, and a second concave portion SBE may be formed.

[0075] Reference Fig.13 , an insulating layer CL1 may be stacked on the connecting portion SB.

[0076] Thereafter, for example, Figure 1 As shown in , a portion of the insulating layer CL1 may be removed to form a second insulating layer CL exposing the protruding portion SBP, the first recessed portion SBC, and the second recessed portion SBE of the connecting portion SB. In some embodiments, Figure 1 The printed circuit board can be based on the Figures 5 to 13 The steps outlined in the formation.

[0077] The height Ha of the first recess SBC and the second recess SBE of the connection portion SB measured from the upper surface of the first insulating layer SUB may be higher than the height Hb of the first portion of the second insulating layer CL measured from the upper surface of the first insulating layer SUB. Fig.13 , the insulating layer CL1 shown in FIG. 1 covers all or at least a majority of the first recess SBC, the second recess SBE and / or the protrusion SBP of the connecting portion SB.

[0078] According to the method for manufacturing a printed circuit board of an embodiment, the connection portion SB may be formed to include a protrusion SBP, a first recess SBC located inside the protrusion SBP, and a second recess SBE located outside the protrusion SBP. As discussed above, when compared with a conventional connection portion in the form of a single column (e.g., not including any recess), the surface area of ​​the portion of the connection portion SB of the present disclosure positioned above the first portion of the second insulating layer CL may be greatly increased.

[0079] According to an embodiment, the surface area of ​​the portion of the connection part SB protruding above the first portion of the second insulating layer CL can be increased by the surface of the protrusion SBP of the connection part SB protruding above the first portion of the second insulating layer CL and the surfaces of the first recess SBC and the second recess SBE of the connection part SB positioned above the first portion of the second insulating layer CL, so that the contact area between the external device and the connection part SB can be relatively larger. Therefore, the adhesion between the external device and the connection part SB can be increased by reducing the shear stress between the external device and the connection part SB, and the contact resistance between the external device and the connection part SB can be reduced to reduce the loss of the electrical signal and reduce the resistance.

[0080] Reference Fig.14 as well as Figures 15 to 17 , a printed circuit board according to another embodiment will be described. Fig.14 is a simplified cross-sectional view of a printed circuit board according to another embodiment, and Figures 15 to 17 yes Fig.14 A top view of a portion of the floor plan.

[0081] Reference Fig.14 According to another embodiment, the printed circuit board is similar to the previous embodiment of Figures 1 to 13 A printed circuit board according to an embodiment is shown and described.

[0082] Reference Fig.14 According to another embodiment, a printed circuit board may include a first insulating layer SUB, a pad portion ML disposed on the first insulating layer SUB, a connecting portion SB disposed on the pad portion ML, and a second insulating layer CL covering a portion of the pad portion ML and a portion of the connecting portion SB.

[0083] The connection portion SB may include a recess SBL formed at the center and having a height Ha, and a protrusion SBH surrounding the recess SBL and having a height higher than the height Ha of the recess SBL.

[0084] The height Ha of the recess SBL of the connection portion SB may be the distance from the lowest point at the center of the connection portion SB to the upper surface of the first insulating layer SUB, and the recess SBL of the connection portion SB may gradually increase in height from the lowest point toward the protrusion SBH of the connection portion SB. For example, the recess SBL may be substantially hemispherical in shape.

[0085] The connection portion SB may protrude over the first portion of the second insulating layer CL and may be connected to an external device.

[0086] Upper surfaces of the recess SBL of the connecting portion SB and the protrusion SBH of the connecting portion SB may be positioned over the first portion of the second insulating layer CL.

[0087] A height Ha of the recess SBL, which may be measured from a point of the recess SBL closest to the first insulating layer SUB to an upper surface of the first insulating layer SUB, may be greater than a height Hb of the second insulating layer CL, which is measured from an upper surface of the first portion of the second insulating layer CL to an upper surface of the first insulating layer SUB. In some embodiments, the recess SBL is disposed completely above an upper surface of the first portion of the second insulating layer CL. For example, the recess SBL is positioned outside the second insulating layer CL and does not extend into the second insulating layer CL.

[0088] In this way, the recess SBL of the connection portion SB may be positioned above the upper surface of the first portion of the second insulating layer CL so that a height Ha (which is a minimum height of the recess SBL of the connection portion SB measured from the upper surface of the first insulating layer SUB) is higher than a height Hb (which is a height measured from the upper surface of the first portion of the second insulating layer CL to the upper surface of the first insulating layer SUB). Therefore, during the manufacturing process, the second insulating layer CL may not remain on the recess SBL of the connection portion SB.

[0089] A lower surface of the connection portion SB may contact the pad portion ML to electrically connect the printed circuit board to an external device.

[0090] The second insulating layer CL may further include an upward protrusion CLP, but the protrusion CLP may be omitted.

[0091] The second insulating layer CL may include a solder resist, but the embodiment is not limited thereto.

[0092] Although not shown, the pad portion ML may be connected to an additional wiring layer disposed under or embedded in the first insulating layer SUB through a via hole formed in the first insulating layer SUB.

[0093] Reference Fig.14 and Fig.15 , the protrusion SBH and the recess SBL of the connection portion SB of the printed circuit board according to another embodiment may have substantially the same outer planar shape.

[0094] The edge of the protrusion SBH and the edge of the recess SBL of the connection portion SB may have a substantially circular outer plan shape. In some embodiments, the edge of the protrusion SBH and the edge of the recess SBL of the connection portion SB may have a substantially elliptical outer plan shape.

[0095] Reference Fig.16 , although the edge of the protrusion SBH of the connection portion SB of the printed circuit board according to another embodiment may have a substantially circular outer planar shape, the edge of the recess SBL of the connection portion SB may have a substantially square outer planar shape.

[0096] Reference Fig.17, although the edge of the protrusion SBH of the connection portion SB of the printed circuit board according to another embodiment may have a substantially circular outer planar shape, the edge of the recess SBL of the connection portion SB may have a polygonal outer planar shape.

[0097] The outer planar shapes of the protruding portion SBH and the recessed portion SBL of the connecting portion SB may be changed in various ways.

[0098] The connection portion SB of the printed circuit board according to another embodiment may include a protrusion SBH and a recess SBL positioned inside the protrusion SBH. When compared with a conventional connection portion in the form of a single column that does not include any recess, the surface area of ​​the connection portion SB protruding above the first portion of the second insulating layer CL (as shown in FIG. Fig.14 and Fig.15 shown and described) may be enlarged.

[0099] Therefore, according to another embodiment, the surface area of ​​the portion of the connection portion SB protruding above the upper surface of the first portion of the second insulating layer CL can be increased, so that the contact area between the external device and the connection portion SB can be relatively larger. Therefore, the adhesion between the external device and the connection portion SB can be increased by reducing the shear stress between the external device and the connection portion SB, and the contact resistance between the external device and the connection portion SB can be reduced to reduce the loss of the electrical signal and reduce the resistance.

[0100] Refer to above Figures 1 to 4 Many features of the printed circuit board according to the described embodiments are applicable to Figures 14 to 17 A printed circuit board according to another embodiment is shown in FIG.

[0101] Reference Figures 18 to 25 as well as Figures 14 to 17 , a method of manufacturing a printed circuit board according to another embodiment will be described. Figures 18 to 25 is a simplified cross-sectional view illustrating a method of manufacturing a printed circuit board according to another embodiment.

[0102] Reference Fig.18 , a pad portion ML may be formed on the first insulating layer SUB. Fig.19 , a first photosensitive film DF1 may be formed (eg, stacked) on the pad portion ML.

[0103] The first photosensitive film DF1 may be photosensitive and may be a dry film, but the embodiment is not limited thereto.

[0104] like Fig. 20 As shown in FIG. 1 , a first hole HL1 at least partially overlapping the pad portion ML may be formed in the first photosensitive film DF1 .

[0105] The protrusion SBH and the recess SBL of the connection portion SB may be provided in the first hole HL1 of the first photosensitive film DF1.

[0106] Reference Fig.21 A metal layer is formed in the first hole HL1 of the first photosensitive film DF1 to form a first portion SB1 of the connecting portion SB.

[0107] Reference Fig. 22 , a second photosensitive film DFA may be formed on the first photosensitive film DF1, and a second hole HL2 exposing a portion of the first portion SB1 of the connection part SB may be formed.

[0108] The second hole HL2 may be formed to correspond to a region of the connection portion SB where the recess SBL of the connection portion SB is to be formed, and a planar shape of the second hole HL2 may be the same as a planar shape of the recess SBL of the connection portion SB. A size (eg, width) of the second hole HL2 may be smaller than a size (eg, width) of the first hole HL1.

[0109] Reference Fig.23 By etching a portion of the first portion SB1 of the connecting portion SB exposed by the second hole HL2 of the second photosensitive film DFA, a recess SBL of the connecting portion SB can be formed. Therefore, a connecting portion SB including a recess SBL disposed at the center and having a small height and a protrusion SBH surrounding the recess SBL and having a large height can be formed.

[0110] Reference Fig.24 , the first photosensitive film DF1 and the second photosensitive film DFA may be removed.

[0111] Reference Fig.25 , an insulating layer CL1 may be stacked on the connecting portion SB.

[0112] Thereafter, a portion of the insulating layer CL1 may be removed to form a second insulating layer CL exposing surfaces of the protrusion SBH and the recess SBL of the connection portion SB, and thus a second insulating layer CL may be formed. Fig.14 of printed circuit boards.

[0113] At this time, the height Ha, which is the lowest height of the recess SBL of the connection portion SB measured from the upper surface of the first insulating layer SUB, may be higher than the height Hb, which is the height measured from the upper surface of the first portion of the second insulating layer CL to the upper surface of the first insulating layer SUB. Therefore, all of the insulating layer CL1 on the recess SBL of the connection portion SB may be removed.

[0114] Based on the method for manufacturing a printed circuit board according to another embodiment, the connection portion SB may be formed to include a protrusion SBH and a recess SBL located within the protrusion SBH. As discussed above, when compared with the conventional connection portion, according to Figures 18 to 25Forming the connecting portion SB by the method shown and described in the accompanying drawings may allow the connecting portion SB to have an increased surface area.

[0115] Therefore, according to another embodiment, the surface area of ​​the protrusion SBH of the connection part SB protruding above the upper surface of the first part of the second insulating layer CL and the recess SBL of the connection part SB positioned above the upper surface of the first part of the second insulating layer can be increased, so that the contact area between the external device and the connection part SB can be relatively large. Therefore, the adhesion between the external device and the connection part SB can be increased by reducing the shear stress between the external device and the connection part SB, and the contact resistance between the external device and the connection part SB can be reduced to reduce the loss of the electrical signal and reduce the resistance.

[0116] While the disclosure has been described in connection with what are presently considered to be practical embodiments, it will be understood that the disclosure is not limited to the disclosed embodiments, but on the contrary, the disclosure is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.

[0117] <symbol description> ML: pad part SB: Connection SBC, SBE, SBL: Concave SBP, SBH, CLP: protrusion SUB, CL: Insulation layer DF1, DF2, DFA: Photosensitive film HL1, HL2: Hole Ha, Hb: height.

Claims

1. A printed circuit board, comprising: a first insulating layer; A pad portion, disposed on the first insulating layer; a connecting portion disposed on the pad portion and comprising a protruding portion and a first recessed portion disposed in the protruding portion; as well as a second insulating layer disposed on the pad portion and exposing a portion of the connection portion, Wherein, the height of the first recess of the connecting portion measured from the upper surface of the first insulating layer is higher than the height of the first part of the second insulating layer adjacent to the connecting portion, and the height of the first part of the second insulating layer is the height measured from the upper surface of the first insulating layer to the upper surface of the first part of the second insulating layer.

2. The printed circuit board according to claim 1, wherein: The first recess of the connection portion is positioned above the first portion of the second insulating layer.

3. The printed circuit board according to claim 2, wherein: The connecting portion further includes a second recessed portion disposed along an edge of the protruding portion.

4. The printed circuit board according to claim 3, wherein: The protrusion surrounds the first recess, and the second recess surrounds the protrusion.

5. The printed circuit board according to claim 3, wherein: A height of the second recess measured from the upper surface of the first insulating layer is higher than a height of the first portion of the second insulating layer.

6. The printed circuit board according to claim 5, wherein: An outer planar shape of the protrusion of the connecting portion and an outer planar shape of the first recessed portion are substantially the same.

7. The printed circuit board according to claim 6, wherein: The outer planar shape of the protrusion of the connection portion and the outer planar shape of the first recessed portion are substantially circular.

8. The printed circuit board according to claim 5, wherein: An outer planar shape of the protrusion of the connection portion and an outer planar shape of the first recess are different from each other.

9. The printed circuit board according to claim 8, wherein: The outer planar shape of the protrusion of the connection portion is substantially circular, and the outer planar shape of the first recess is polygonal.

10. The printed circuit board according to claim 8, wherein: The outer planar shape of the protrusion of the connection portion is substantially circular, and the outer planar shape of the first recess is elliptical.

11. The printed circuit board according to claim 2, wherein: The height of the first recessed portion decreases from the protruding portion toward a center of the connecting portion.

12. The printed circuit board according to claim 1, wherein: The height of the first recess is a height measured from the upper surface of the first insulating layer to the lowest point of the first recess.

13. The printed circuit board according to claim 12, wherein: The protrusion surrounds the first recess.

14. A method for manufacturing a printed circuit board, the method comprising: forming a pad portion on the first insulating layer; forming a first photosensitive film having a first hole overlapping the pad portion on the pad portion; forming a metal layer in the first hole of the first photosensitive film; forming a second photosensitive film having a second hole overlapping a portion of the metal layer; as well as The metal layer is processed to form a connection portion, the connection portion including a protrusion and a first recess disposed in the protrusion.

15. The method for manufacturing a printed circuit board according to claim 14, wherein: The second photosensitive film is formed after removing the first photosensitive film.

16. The method for manufacturing a printed circuit board according to claim 15, wherein: The second hole of the second photosensitive film is formed to correspond to the protrusion of the connection part.

17. The method for manufacturing a printed circuit board according to claim 16, wherein: In the step of processing the metal layer, another metal layer is formed on the metal layer to fill the second hole.

18. The method for manufacturing a printed circuit board according to claim 17, wherein: The connecting portion is formed to further include a second recessed portion provided along an edge of the protruding portion, And the second hole of the second photosensitive film is formed not to overlap with the second concave portion.

19. The method for manufacturing a printed circuit board according to claim 14, wherein: forming the second photosensitive film on the first photosensitive film, And the width of the second hole of the second photosensitive film is narrower than the width of the first hole of the first photosensitive film.

20. The method for manufacturing a printed circuit board according to claim 19, wherein: In the step of processing the metal layer, a portion of the metal layer exposed by the second hole in the second photosensitive film is etched to form the first recess.

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