Printed circuit board and manufacturing method thereof

Abstract

To provide a printed circuit board and a manufacturing method thereof capable of preventing a pad portion from being separated from the printed circuit board and lost.SOLUTION: A printed circuit board may include: a first insulating layer; a pad portion located on the first insulating layer; a connection layer located on the pad portion and including a central portion and an extension portion extending from the central portion toward an edge of the pad portion; and a second insulating layer located on a portion of the pad portion and a portion of the connection layer. The extension portion of the connection layer may be located within a groove portion formed in the second insulating layer. An upper surface of the extension portion of the connection layer may be covered with the second insulating layer.SELECTED DRAWING: Figure 1

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, such as mobile phones, are miniaturized, the size of metal posts formed on printed circuit boards on which electronic components are mounted is also decreasing.

[0003] As the size of the metal posts on the printed circuit board decreases, the metal posts may be separated from the printed circuit board and disappear.

Disclosure of the Invention

Problems to be Solved by the Invention

[0004] An embodiment provides a printed circuit board and a method for manufacturing the same that can prevent a pad portion from being separated from and disappearing from the printed circuit board.

[0005] However, the problems to be solved by the embodiment are not limited to the above-described problems, and can be variously extended within the scope of the technical idea included in the embodiment.

[0006] The printed circuit board according to the embodiment may include a first insulating layer, a pad portion located on the first insulating layer, a connection layer located on the pad portion and including a central portion and an extension portion extending from the central portion toward an edge portion of the pad portion, and a second insulating layer located on a part of the pad portion and a part of the connection layer. The extension portion of the connection layer may be located in a groove portion formed in the second insulating layer, and an upper surface of the extension portion of the connection layer may be covered with the second insulating layer.

[0007] The groove portion may be located on a lower surface of the second insulating layer.

[0008] A lower surface of the extension portion of the connection layer may be in contact with the pad portion.

[0009] The central portion of the connection layer may protrude above the second insulating layer.

[0010] The connection layer may further include a convex portion that extends downward from the central portion and the extension portion.

[0011] The pad portion may include a recess formed on the upper surface of the pad portion.

[0012] The convex portion of the connection layer may be located within the recess of the pad portion.

[0013] The convex portion of the connection layer may be in contact with the pad portion.

[0014] The method for manufacturing a printed circuit board according to the embodiment may include a step of forming a pad portion on a first insulating layer, a step of laminating a photosensitive film on the pad portion, a step of forming a hole in the photosensitive film, a step of forming a groove portion extending from the hole in the photosensitive film, and a step of laminating a metal layer on the hole and the groove portion to form a connection layer including a central portion located in the hole and an extension portion located in the groove portion.

[0015] The method for manufacturing the printed circuit board may further include a step of removing the photosensitive film and a step of laminating a second insulating layer on the pad portion and the connection layer.

[0016] The method for manufacturing the printed circuit board may further include a step of removing a portion of the second insulating layer so that the central portion of the connection layer protrudes above the second insulating layer.

[0017] The groove portion may be formed on the lower surface of the photosensitive film.

[0018] The lower surface of the extension portion of the connection layer may be formed to be in contact with the pad portion on the pad portion.

[0019] The method for manufacturing the printed circuit board may further include a step of removing a part of the upper surface of the pad portion overlapping with the hole of the photosensitive film to form a concave portion on the upper surface of the pad portion.

[0020] The step of forming the connection layer may further include a step of forming a convex portion extending downward from the central portion and the extension portion.

[0021] The convex portion of the connection layer may be formed in the concave portion of the pad portion.

[0022] The convex portion of the connection layer may be formed on the pad portion so as to contact the pad portion.

[0023] According to the embodiment, it is possible to provide a printed circuit board and a method for manufacturing the same that can prevent the pad portion from being separated and disappearing from the printed circuit board.

[0024] However, the effects of the embodiment are not limited to the above-described effects, and it is obvious that they can be variously extended within a range not deviating from the spirit and scope of the present invention.

Brief Description of the Drawings

[0025]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

[0026] Hereinafter, with reference to the accompanying drawings, the present invention will be described in detail so that those skilled in the art to which the present invention pertains can easily implement various embodiments of the present invention. The present invention can be embodied in various different forms and is not limited to the embodiments described herein.

[0027] For the sake of clarity in the description of the present invention, parts that are unnecessary for the description are omitted, and the same reference numerals will be assigned to the same or similar components throughout the specification.

[0028] Also, the accompanying drawings are only for facilitating the understanding of the embodiments disclosed in this specification, and the technical ideas disclosed in this specification are not limited by the accompanying drawings. It should be understood that the drawings include all modifications, equivalents, or alternatives included in the spirit and technical scope of the present invention.

[0029] In addition, the sizes and thicknesses of the respective components shown in the drawings are arbitrarily shown for the convenience of explanation, and the present invention is not necessarily limited to those shown. The thicknesses are enlarged in the drawings to clearly represent various layers and regions. And in the drawings, for the convenience of explanation, the thicknesses of some layers and regions are exaggerated.

[0030] Also, when a part such as a layer, film, region, or plate is "on" or "above" another part, this includes not only the case where it is directly above the other part but also the case where there are other parts in between. Conversely, when a part is "directly above" another part, it means that there are no other parts in between. Also, being "on" or "above" a reference part means being located above or below the reference part, and does not necessarily mean being located "on" or "above" in the direction opposite to gravity.

[0031] Also, throughout the specification, when a part "includes" a certain component, this means that it can further include other components rather than excluding other components, unless otherwise stated to the contrary.

[0032] Also, throughout the specification, when it is said "on a plane", this means when looking at the target part from above, and when it is said "in a cross-section", this means when looking at the cross-section obtained by vertically cutting the target part from the side.

[0033] Also, throughout the specification, when it is said "connected", this does not only mean that two or more components are directly connected, but also means that two or more components are indirectly connected through other components, not only physically connected but also electrically connected, or can mean being integrated although referred to by different names depending on position or function.

[0034] Hereinafter, various embodiments and modifications will be described in detail with reference to the drawings.

[0035] With reference to FIG. 1, a printed circuit board according to an embodiment will be described. FIG. 1 is a schematic cross-sectional view of a printed circuit board according to the embodiment.

[0036] Referring to FIG. 1, the printed circuit board according to this embodiment may include a first insulating layer SUB, a pad portion ML located on the first insulating layer SUB, a connection layer SB located on the pad portion ML, and a second insulating layer CL covering a part of the pad portion ML and a part of the connection layer SB.

[0037] The second insulating layer CL may have a groove portion CV located above the pad portion ML. The groove portion CV of the second insulating layer CL may be formed on the lower surface of the second insulating layer CL, and the groove portion CV of the second insulating layer CL may be in a form that expands toward the edge of the pad portion ML.

[0038] The second insulating layer CL may include a solder resist, but the embodiments are not limited thereto.

[0039] The connection layer SB may include a central portion SBP protruding above the second insulating layer CL and an extension portion SBW extending from the side surface of the central portion SBP.

[0040] The central portion SBP of the connection layer SB may have a columnar shape, protrude upward from the surface of the second insulating layer CL, and may be connected to an external element.

[0041] The connection layer SB can be in contact with the pad portion ML to electrically connect the printed circuit board to the external element.

[0042] The extension portion SBW of the connection layer SB may extend from the lower part to the side surface of the central portion SBP and may be located within the groove portion CV of the second insulating layer CL. The upper surface of the extension portion SBW of the connection layer SB is covered by the second insulating layer CL, and the lower surface of the extension portion SBW of the connection layer SB can be in contact with the pad portion ML.

[0043] Although not shown, the pad portion ML may be located below the first insulating layer SUB through a via formed in the first insulating layer SUB or may be connected to an additional wiring layer embedded in the first insulating layer SUB.

[0044] The printed circuit board may be connected to the external element via the connection layer SB including the central portion SBP protruding above the second insulating layer CL. Therefore, the printed circuit board can be connected to the external element with a cross-sectional area smaller than that of the pad portion ML.

[0045] According to the embodiment, the extension portion SBW of the connection layer SB is located within the groove portion CV formed inside the second insulating layer CL, so that the extension portion SBW of the connection layer SB can be covered by the second insulating layer CL. Therefore, compared with the case where the connection layer SB consists only of the central portion SBP without including the extension portion SBW, it is possible to prevent the connection layer SB from disappearing from the printed circuit board due to external forces or loads applied from the outside as when the connection layer SB comes into contact with an external element.

[0046] According to the embodiment, the lower surface of the extension portion SBW of the connection layer SB can be in contact with the pad portion ML, and compared with the case where the connection layer SB consists only of the central portion SBP without including the extension portion SBW, the contact area between the connection layer SB and the pad portion ML can be relatively large. Therefore, the shear stress between the pad portion ML and the connection layer SB can be reduced, the adhesion between the pad portion ML and the connection layer SB can be increased, the contact resistance between the pad portion ML and the connection layer SB can be reduced to reduce the loss of electrical signals, and the electrical resistance can be reduced.

[0047] With reference to FIGS. 2 to 5 together with FIG. 1, a method for manufacturing a printed circuit board according to an embodiment will be described. FIGS. 2 to 5 are schematic cross-sectional views showing a method for manufacturing a printed circuit board according to an embodiment.

[0048] Referring to FIG. 2, the pad portion ML may be formed on the first insulating layer SUB, and a photosensitive film DF may be laminated on the pad portion ML to form a hole HL overlapping the pad portion ML.

[0049] The hole HL of the photosensitive film DF may be formed at a portion where the columnar central portion SBP of the connection layer SB is formed.

[0050] The photosensitive film DF may have photosensitivity and may be a dry film, but the embodiment is not limited thereto.

[0051] Referring to FIG. 3, a first groove portion HLW extended toward the edge of the pad portion ML can be formed on the lower surface of the hole HL of the photosensitive film DF. The first groove portion HLW of the photosensitive film DF can be formed by etching a part of the lower surface of the photosensitive film DF by adjusting the etching conditions. The first groove portion HLW of the photosensitive film DF can correspond to the groove portion CV of the second insulating layer CL.

[0052] Referring to FIG. 4, a metal layer can be formed in the hole HL and the first groove portion HLW of the photosensitive film DF, and a central portion SBP of the connection layer SB located in the hole HL of the photosensitive film DF and an extended portion SBW of the connection layer SB located in the first groove portion HLW can be formed. The metal layer may be formed by a method such as electrolytic plating, but the embodiment is not limited thereto.

[0053] Referring to FIG. 5, the photosensitive film DF can be removed.

[0054] Thereafter, the second insulating layer CL can be laminated, and the height of the second insulating layer CL can be lowered so as to expose the central portion SBP of the connection layer SB, and the printed circuit board shown in FIG. 1 can be formed.

[0055] Referring to FIG. 6, a printed circuit board according to another embodiment will be described. FIG. 6 is a schematic cross-sectional view of a printed circuit board according to another embodiment.

[0056] Referring to FIG. 6, the printed circuit board according to this embodiment is similar to the printed circuit board according to the embodiment described with reference to FIG. 1 above. Specific descriptions of the same components can be omitted.

[0057] Referring to FIG. 6, the printed circuit board according to this embodiment may include a first insulating layer SUB, a pad portion ML located on the first insulating layer SUB, a connection layer SB located on the pad portion ML, and a second insulating layer CL covering a part of the pad portion ML and a part of the connection layer SB.

[0058] On the lower surface of the second insulating layer CL, a groove portion CV having a shape that is located above the pad portion ML and extends toward the edge of the pad portion ML may be formed.

[0059] The connection layer SB may include a central portion SBP protruding above the second insulating layer CL and an extension portion SBW extending from the side surface of the central portion SBP.

[0060] The printed circuit board according to this embodiment may include a recess MLC formed on the upper surface of the pad portion ML, which is different from the printed circuit board according to the embodiment of FIG. 1, and the connection layer SB may further include a convex portion SBC located within the recess MLC of the pad portion ML.

[0061] The central portion SBP of the connection layer SB may have a columnar shape, protrude upward from the surface of the second insulating layer CL, and may be connected to an external element.

[0062] The extension portion SBW of the connection layer SB may extend from the lower portion to the side surface of the central portion SBP and may be located within the groove portion CV of the second insulating layer CL.

[0063] The convex portion SBC of the connection layer SB may extend downward into the recess MLC of the pad portion ML from the central portion SBP and the lower portion of the extension portion SBW of the connection layer SB.

[0064] The printed circuit board may be connected to an external element via the connection layer SB including the central portion SBP protruding above the second insulating layer CL. Therefore, the printed circuit board can be connected to the external element with a smaller cross-sectional area than the pad portion ML.

[0065] According to the embodiment, the extension portion SBW of the connection layer SB is located within the groove portion CV formed inside the second insulating layer CL, so that the extension portion SBW of the connection layer SB can be covered by the second insulating layer CL. Therefore, compared with the case where the connection layer SB consists only of the central portion SBP without including the extension portion SBW, it is possible to prevent the connection layer SB from disappearing from the printed circuit board due to external forces or loads applied from the outside, such as when the connection layer SB contacts an external element.

[0066] According to the embodiment, the central portion SBP of the connection layer SB and the convex portion SBC of the connection layer SB extended from the lower portion of the extended portion SBW are located within the concave portion MLC of the pad portion ML, and the contact area between the connection layer SB and the pad portion ML can be relatively widened. Therefore, the shear stress between the pad portion ML and the connection layer SB can be reduced, the adhesion between the pad portion ML and the connection layer SB can be enhanced, the contact resistance between the pad portion ML and the connection layer SB can be reduced to reduce the loss of electrical signals, and the electrical resistance can be reduced.

[0067] Many features of the printed circuit board according to the embodiment described with reference to FIG. 1 above are all applicable to the printed circuit board according to this embodiment.

[0068] With reference to FIGS. 7 to 10 together with FIG. 6, a manufacturing method of a printed circuit board according to an embodiment will be described. FIGS. 7 to 10 are schematic cross-sectional views showing a manufacturing method of a printed circuit board according to another embodiment.

[0069] Referring to FIG. 7, a pad portion ML may be formed on the first insulating layer SUB, and a photosensitive film DF may be laminated on the pad portion ML to form a hole HL overlapping the pad portion ML.

[0070] The hole HL of the photosensitive film DF may be formed at a portion where the columnar central portion SBP of the connection layer SB is formed.

[0071] The photosensitive film DF may have photosensitivity and may be a dry film, but the embodiment is not limited thereto.

[0072] Referring to FIG. 8, a first groove portion HLW extending toward the edge of the pad portion ML can be formed on the lower surface of the hole HL of the photosensitive film DF, and a concave portion MLC of the pad portion ML can be formed by etching a part of the upper surface of the pad portion ML. The first groove portion HLW of the photosensitive film DF may be formed by etching a part of the lower surface of the photosensitive film DF by adjusting the etching conditions, and the concave portion MLC of the pad portion ML may be formed by etching the upper surface of the pad portion ML exposed by the hole HL and the groove portion HLW of the photosensitive film DF by adjusting the etching conditions.

[0073] Referring to FIG. 9, a metal layer is formed in the hole HL, the first groove portion HLW of the photosensitive film DF, and the concave portion MLC of the pad portion ML, and a central portion SBP of the connection layer SB located in the hole HL of the photosensitive film DF, an extension portion SBW of the connection layer SB located in the groove portion HLW, and a convex portion SBC of the connection layer SB located in the concave portion MLC of the pad portion ML are formed.

[0074] Referring to FIG. 10, the photosensitive film DF can be etched and removed. Then, the second insulating layer CL is laminated, and the height of the second insulating layer CL is reduced so as to expose the central portion SBP of the connection layer SB, and the printed circuit board shown in FIG. 6 can be formed.

[0075] Many features of the method for manufacturing a printed circuit board according to the embodiment described with reference to FIGS. 2 to 5 are all applicable to the method for manufacturing a printed circuit board according to this embodiment.

[0076] As described above, the preferred embodiments of the present invention have been described, but the present invention is not limited thereto, and various modifications can be made within the scope of the claims, the detailed description of the invention, and the accompanying drawings, and it is natural that these also belong to the scope of the present invention.

Description of Reference Numerals

[0077] ML: Pad portion MLC: Concave portion SB: Connection layer SBP: Central portion SBW: Extension portion SBC: Convex part SUB, CL: Insulating layer CV: Groove part

Claims

1. A first insulating layer; a pad portion located on the first insulating layer; a connection layer located on the pad portion and including a central portion and an extension portion extending from the central portion toward an edge of the pad portion; a second insulating layer located on a portion of the pad portion and a portion of the coupling layer; the extension of the coupling layer is located in a groove formed in the second insulating layer, and a top surface of the extension of the coupling layer is covered by the second insulating layer.

2. The printed circuit board of claim 1 , wherein the groove is located on a bottom surface of the second insulating layer.

3. The printed circuit board of claim 2 , wherein a lower surface of the extension portion of the connection layer contacts the pad portion.

4. The printed circuit board of claim 3 , wherein the central portion of the connection layer protrudes above the second insulating layer.

5. The printed circuit board of claim 2 , wherein the connection layer further includes a convex portion extending downward from the central portion and the extension portion.

6. The printed circuit board of claim 5 , wherein the pad portion includes a recess formed on an upper surface of the pad portion.

7. The printed circuit board according to claim 6 , wherein the convex portion of the coupling layer is located within the concave portion of the pad portion.

8. The printed circuit board according to claim 7 , wherein the protrusion of the coupling layer contacts the pad portion.

9. The printed circuit board of claim 8 , wherein the center portion of the connection layer protrudes above the second insulating layer.

10. The printed circuit board of claim 1 , wherein the central portion of the connection layer protrudes above the second insulating layer.

11. forming a pad portion on the first insulating layer; laminating a photosensitive film on the pad portion; forming holes in the photosensitive film; forming a groove portion extending from the hole in the photosensitive film; and depositing a metal layer in the hole and in the groove to form a connection layer having a center portion located in the hole and an extension portion located in the groove.

12. removing the photosensitive film; The method of claim 11 , further comprising: laminating a second insulating layer on the pad portion and the connection layer.

13. The method of claim 12 , further comprising removing a portion of the second insulating layer such that the center portion of the connection layer protrudes above the second insulating layer.

14. The method of claim 11, wherein the groove is formed on a lower surface of the photoresist film.

15. The method of claim 14 , wherein a lower surface of the extension portion of the connection layer is formed on and in contact with the pad portion.

16. 16. The method of claim 11, further comprising removing a portion of an upper surface of the pad portion that overlaps with the hole of the photoresist film to form a recess in the upper surface of the pad portion.

17. The method of claim 16 , wherein the step of forming the connection layer further comprises forming a convex portion extending downward from the center portion and the extension portion.

18. The method of claim 17 , wherein the convex portion of the connection layer is formed in the concave portion of the pad portion.

19. The method of claim 18 , wherein the convex portion of the connection layer is formed on and in contact with the pad portion.

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