KR20070049822A - Laminate for fabricating printed circuit board and method of fabricating printed circuit board - Google Patents

Abstract

In manufacturing a printed circuit board, a laminate for a printed circuit board including a pad film and a method of manufacturing a printed circuit board using the same are provided. The present invention includes a step of preparing a laminate for a printed circuit board including a pad film. And forming an etch stop layer pattern on the printed circuit board laminate, etching the pad layer exposed from the etch stop layer pattern, removing the etch stop layer, and forming a solder resist pattern. According to the present invention, it is possible to prevent the black pad phenomenon, which is a problem in the conventional PCB manufacturing process, and to maintain the wettability and reliability of the solder.

Printed Circuit Board, Copper Clad Laminated Board

Description

Laminate for printed circuit board and manufacturing method of printed circuit board using the same {Laminate for fabricating printed circuit board and method of fabricating printed circuit board}

1 is a cross-sectional view illustrating a copper clad laminate used in a manufacturing process of a conventional printed circuit board.

FIG. 2 is a cross-sectional photograph illustrating a black pad phenomenon appearing in a solder joint in a printed circuit board manufactured by a conventional printed circuit board manufacturing process. FIG.

3A to 3C are cross-sectional views illustrating laminates for a printed circuit board used in a manufacturing process of a printed circuit board according to embodiments of the present invention.

4A to 4H are cross-sectional views illustrating a method of manufacturing a printed circuit board according to the first embodiment of the present invention.

5A to 5G are cross-sectional views illustrating a method of manufacturing a printed circuit board according to the second embodiment of the present invention.

6A through 6G are cross-sectional views illustrating a method of manufacturing a printed circuit board according to a third exemplary embodiment of the present invention.

The present invention relates to a printed circuit board laminate and a method of manufacturing a printed circuit board using the same, and more particularly to a printed circuit board laminate including a pad film and a method of manufacturing a printed circuit board using the same.

Printed Circuit Board (PCB) is one of the most basic electronic components that plays a role of connecting the components installed by installing electronic components such as various chips thereon. In general, a copper clad laminate (CCL) illustrated in FIG. 1 is used in the manufacturing process of the printed circuit board. Referring to FIG. 1, a copper foil laminated plate includes a copper foil 2 on a substrate 1. The conventional process of manufacturing a printed circuit board using such a copper-clad laminate is as follows. The copper foil laminated plate is patterned using a predetermined etching process to form a copper foil pattern. Subsequently, a solder resist is coated and patterned to form a solder resist pattern. An ENIG pad is then formed through an electroless Nickel Immersion Gold (ENIG) process in addition to the areas where the solder resist pattern has been removed.

However, this conventional process is when the ENIG pad is bonded to the solder, the phenomenon occurs where the ENIG pad and the solder 3 is not bonded, as shown in Figure 2, that is, generally black pad (4, Black Pad) There is a problem that is called a phenomenon that seriously affects the reliability of the solder joint. Although the cause of the black pad 4 has not been precisely determined to date, a P-rich layer is formed when the nickel plating layer formed by the electroless plating method and the solder are bonded to each other. It is reported that the nickel plating layer is oxidized. Instead of using ENIG pads to solve these problems, OSP (Organic Solderability Preservative) pads are sometimes used, but they are considered inferior to ENIG pads in terms of wettability and reliability with solder.

The present invention has been made in order to solve the problem that the black pad occurs as described above, to provide a laminated board for a printed circuit board that can prevent the black pad phenomenon which is a technical problem to be achieved by the present invention, and to achieve the present invention Another object of the present invention is to provide a method for manufacturing a printed circuit board using the laminate for a printed circuit board.

According to the method of manufacturing a printed circuit board of the present invention for achieving the above object, a laminate for a printed circuit board comprising a substrate, a copper foil formed on the substrate and a pad film formed on the copper foil is prepared. An etch stop layer pattern is formed on the laminate for the printed circuit board. Subsequently, after etching the pad layer exposed from the etch stop layer pattern, the etch stop layer is removed, and then a solder resist pattern is formed.

Hereinafter, preferred embodiments of the present invention will be described in detail. However, the present invention should not be construed as limited to the following examples.

First, various exemplary embodiments of a laminate for a printed circuit board including a pad film will be described in detail. However, the term pad film as used herein refers to a metal foil formed on the copper foil 2 in a printed circuit board laminate, and specifically what kind of metal material is included in the following examples Explain.

3A is a cross-sectional view showing a first embodiment of a laminate for a printed circuit board. Referring to FIG. 3A, a copper foil 2 is formed on the substrate 1, and a first pad film 5 containing nickel foil is formed on the copper foil 2. The first pad film 5 may be formed on the copper foil 2 in various ways, preferably a method of electroplating nickel on the copper foil 2, a method of sputtering nickel on the copper foil 2, or It can be formed using any one of the method of laminating nickel foil on the copper foil 2.

3B is a cross-sectional view showing a second embodiment of a laminate for a printed circuit board. Referring to FIG. 3B, a copper foil 2 is formed on the substrate 1, and a second pad film 6 including gold foil is formed on the copper foil 2. The second pad film 6 may be formed on the copper foil 2 in various ways, preferably a method of electroplating gold on the copper foil 2, a method of sputtering gold on the copper foil 2, or a copper foil of a gold foil (2) can be formed using any of the methods of laminating above.

3C is a cross-sectional view showing a third embodiment of a laminate for a printed circuit board. Referring to FIG. 3C, a copper foil 2 is formed on the substrate 1, and a third pad film 7 including nickel foil and gold foil is formed on the copper foil 2. Preferably, the third pad film 7 may include a nickel foil formed on the copper foil 2 and a gold foil formed on the nickel foil. The third pad film 7 may be formed on the copper foil 2 in various ways, preferably a method of electroplating gold and nickel on the copper foil 2, and a method of sputtering gold and nickel on the copper foil 2. Or it can be formed using any one of the method of laminating the gold foil and nickel foil on the copper foil (2).

Description of the first to third embodiments of the laminated board for a printed circuit board has been exemplarily described for the laminated board for a single-sided printed circuit board having a pad film formed on an upper surface of the substrate 1. However, the present invention is not limited thereto, and of course, the case of a laminate for a double-sided printed circuit board, in which metal foils of the same shape are symmetrically formed on both top and bottom surfaces of the substrate 1, is also included. That is, the copper foil 2 is formed on both surfaces of the upper surface and the lower surface of the substrate 1, and the pad film may be formed on the copper foil 2 in the form of vertical symmetry.

Hereinafter, exemplary embodiments of a method of manufacturing a printed circuit board using a laminate for a printed circuit board will be described in detail.

4A to 4H are cross-sectional views illustrating a method of manufacturing a printed circuit board, and show a first embodiment of a method of manufacturing a printed circuit board using the laminate for a printed circuit board of the first embodiment described above.

Referring to FIG. 4A, a laminate for a printed circuit board including a substrate 1, a copper foil 2 formed on the substrate 1, and a first pad film 5 formed on the copper foil 2 is prepared. As described above, the first pad layer 5 may be formed on the copper foil 2 through various methods.

Referring to FIG. 4B, an etch stop film 8 is formed on the laminate for a printed circuit board. In this case, various materials may be used as the anti-etching film 8, and preferably a dry film may be used as the anti-etching film 8.

Referring to FIG. 4C, the etch stop layer 8 is patterned to form an etch stop layer pattern 8 ′. Therefore, the first pad layer 5 is exposed from the etch stop layer pattern 8 ′.

Referring to FIG. 4D, the first pad film 5 and the copper foil 2 exposed from the etch stop layer pattern 8 ′ are sequentially etched to form the first pad film pattern 5 ′ and the copper foil pattern 2 ′. Form. In this case, each of the first pad film 5 and the copper foil 2 may be sequentially etched using a different etching solution. Preferably, the first pad film 5 and the copper foil 2 may be etched in the same manner. Etch solutions can be used to etch simultaneously.

Referring to FIG. 4E, the etch stop layer pattern 8 ′ is removed.

Referring to FIG. 4F, the solder resist 9 is coated on the surface of the PCB for which the etch stop layer pattern 8 ′ has been removed, thereby masking the surface of the laminate and preventing solder bridge. . At this time, several kinds of solder resists may be used, and preferably photo solder resists may be used.

Referring to FIG. 4G, the solder resist 9 is patterned to form a solder resist pattern 9 '. As a result, the first pad film pattern 5 'is exposed from the solder resist pattern 9'.

Referring to FIG. 4H, a gold foil 10 is formed on the first pad film pattern 5 ′ exposed from the solder resist pattern 9 ′ to form a pad to be bonded to the solder. Preferably, before forming the gold foil 10, a process of performing a predetermined surface treatment on the exposed surface of the first pad film pattern 5 ′ may be added. This is to prevent the nickel contained in the first pad film pattern 5 ′ from being oxidized during the process of forming the gold foil 10.

5A to 5G are cross-sectional views illustrating a method of manufacturing a printed circuit board, and show a second embodiment of a method of manufacturing a printed circuit board using the laminate for a printed circuit board of the second embodiment described above.

Referring to FIG. 5A, a laminate for a printed circuit board including a substrate 1, a copper foil 2 formed on the substrate 1, and a second pad film 6 formed on the copper foil 2 is prepared. As described above, the second pad layer 6 may be formed on the copper foil 2 through various methods.

Referring to FIG. 5B, an etch stop film 8 is formed on the laminate for a printed circuit board. In this case, various materials may be used as the anti-etching film 8, and preferably a dry film may be used as the anti-etching film 8.

Referring to FIG. 5C, the etch stop layer 8 is patterned to form an etch stop layer pattern 8 ′. Therefore, the second pad layer 6 is exposed from the etch stop layer pattern 8 ′.

Referring to FIG. 5D, the second pad layer 6 and the copper foil 2 exposed from the etch stop layer pattern 8 ′ are sequentially etched to form the second pad layer pattern 6 ′ and the copper foil pattern 2 ′. Form. In this case, the second pad film 6 and the copper foil 2 may be sequentially etched using different etching solutions, respectively. Preferably, the first pad film 6 and the copper foil 2 may be etched in the same manner. Etch solutions can be used to etch simultaneously.

Referring to FIG. 5E, the etch stop layer pattern 8 ′ is removed.

Referring to FIG. 5F, the solder resist 9 is coated on the surface of the PCB for which the etch stop layer pattern 8 ′ has been removed, thereby masking the surface of the laminate and preventing solder bridges. do. At this time, several kinds of solder resists may be used, and preferably photo solder resists may be used.

Referring to FIG. 5G, the solder resist 9 is patterned to form a solder resist pattern 9 ′. As a result, the first pad layer pattern 6 'is exposed from the solder resist pattern 9', thereby forming pads to be bonded to the solder.

6A to 6G are cross-sectional views illustrating a method of manufacturing a printed circuit board, and show a third embodiment of a method of manufacturing a printed circuit board using the laminate for a printed circuit board of the third embodiment described above.

The printed circuit board manufacturing method in the third embodiment differs from the manufacturing method of the second embodiment described above in that the laminated board for the printed circuit board includes the third pad film described above. Therefore, the third embodiment is different from the second embodiment in the etching process, the rest of the process proceeds in the same manner as the second embodiment. Therefore, hereinafter, the etching process of the third embodiment will be described in detail and detailed description of the remaining processes will be omitted.

Referring to FIG. 6D, the third pad layer 7 and the copper foil 2 exposed from the etch stop layer pattern 8 ′ are sequentially etched to form the third pad layer pattern 7 ′ and the copper foil pattern 2 ′. Form. In this case, each of the third pad film 7 and the copper foil 2 may be sequentially etched using a different etching solution. Preferably, the third pad film 7 and the copper foil 2 may be identically etched. Etch solutions can be used to etch simultaneously.

Referring to FIG. 6G, the solder resist 9 is patterned to form a solder resist pattern 9 '. As a result, the third pad layer pattern 7 'is exposed from the solder resist pattern 9', thereby forming a pad to be bonded to the solder.

Description of the first to third embodiments of the method for manufacturing a printed circuit board is an example of a method for manufacturing a printed circuit board using a laminate for a single-sided printed circuit board having a pad film formed on an upper surface of the substrate 1. As explained with reference. However, the present invention is not limited thereto, and the method of manufacturing a printed circuit board using a laminate for a double-sided printed circuit board, in which metal foils of the same shape are symmetrically formed on both upper and lower surfaces of the substrate 1, of course, is also included. That is, the copper foil 2 is formed on both surfaces of the upper surface and the lower surface of the substrate 1, and the pad film may be formed on the copper foil 2 in the form of vertical symmetry. In addition, each process step included in the above-described embodiments is performed on pad films formed on both upper and lower surfaces.

Although the present invention has been described with reference to the above embodiments, the present invention is not limited to the above-described embodiments, but the present embodiments are merely to make the disclosure of the present invention complete, and to those skilled in the art the scope of the invention. It is apparent that various modifications and improvements are possible to those skilled in the art without departing from the spirit and scope of the present invention as provided to fully inform the present invention.

As described above, the laminate of the printed circuit board and the method of manufacturing the printed circuit board using the same according to the present invention can prevent the black pad phenomenon occurring when the electroless nickel plating layer and the solder are bonded by not using the electroless nickel plating. The wettability and reliability of the solder can be maintained.

Claims (12)

Board; Copper foil formed on the substrate; And And a pad film formed on the copper foil and including a gold foil or a nickel foil. The laminate of claim 1, wherein the copper foil is formed on both surfaces of an upper surface and a lower surface of the substrate. The laminate of claim 1, wherein the pad film comprises nickel foil and gold foil. 4. The laminate of claim 3, wherein the gold foil of the pad film is formed on the nickel foil of the pad film. Preparing a laminate for a printed circuit board comprising a substrate, a copper foil formed on the substrate, and a pad film formed on the copper foil and comprising a gold foil or a nickel foil; Forming an etch stop layer pattern exposing the pad layer on the laminate for the printed circuit board; Sequentially etching the pad film and the copper foil exposed from the etch stop layer pattern to form a pad film pattern and a copper foil pattern; Removing the etch stop layer pattern; And And forming a solder resist pattern exposing the pad foil pattern on the laminate for the printed circuit board from which the etch stop layer pattern has been removed. The method of claim 5, wherein the step of sequentially etching the pad layer and the copper foil is performed using the same etching solution. The method of claim 5, wherein the pad film comprises nickel foil, and after forming the solder resist pattern, further comprising the step of forming a gold foil on the pad film exposed from the solder resist pattern. Printed circuit board manufacturing method. The method of claim 7, further comprising, after the forming of the solder resist pattern, surface treating the surface of the pad layer exposed from the solder resist pattern. The method of claim 5, wherein the pad layer comprises nickel foil and gold foil. The method of claim 9, wherein the gold foil of the pad film is formed on the nickel foil of the pad film. The method of claim 9, wherein the step of sequentially etching the pad film and the copper foil is performed using the same etching solution. The method of claim 5, wherein the copper foil is formed on an upper surface and a lower surface of the substrate.

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