KR20080083532A - Printed circuit board and method of manufacturing the same - Google Patents

Abstract

The present invention provides a printed circuit board and a method of manufacturing the via hole formed in the substrate to improve the filling property of the insulating material of the via hole by forming a larger cross-sectional area on one surface than the cross-sectional area on one surface of the substrate. Is initiated. An aspect of the present invention includes a base substrate including at least one or more via holes penetrating both sides, wherein the via hole has a larger cross-sectional area at one surface of the base substrate than at another surface thereof, and the via hole is insulated. Provided is a printed circuit board filled with a material.

Description

Printed circuit board and method of manufacturing the same

1 is a cross-sectional view schematically showing a printed circuit board on which a tapered via hole is formed as a preferred embodiment of the present invention.

2 is a cross-sectional view schematically showing a printed circuit board on which a stepped via hole is formed, according to another exemplary embodiment of the present invention.

3 is a flowchart schematically illustrating a method of manufacturing the printed circuit board of FIGS. 1 and 2.

FIG. 4 is a diagram schematically illustrating an embodiment of forming the via hole of FIG. 3.

FIG. 5 schematically illustrates another embodiment of forming the via hole of FIG. 3.

<Explanation of symbols for main parts of the drawings>

100, 200: printed circuit board,

110, 210: base substrate, 111, 211: core substrate,

111a, 211a: via hole, 112, 212: thin film layer,

130, 230: plating layer, 140, 240: insulating layer.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printed circuit board and a method for manufacturing the same, and more particularly, to be used in an electronic device, an electronic device, a computer, and a semiconductor package for mounting a telecommunication device or semiconductor. It relates to a printed circuit board and a method of manufacturing the same).

In general, various components constituting a circuit are soldered onto a printed circuit board on which circuit parts of various electronic products are integrated. For insulation and board protection, all parts except solder are to be coated with ink. To this end, a process of printing and / or marking an insulating material such as SR (Solder Resist) or PSR (Photo Solder Resist) is performed.

In particular, the SR printing is applied to the remaining portions of the printed circuit board other than the soldering portion with ink to ensure insulation between the parts, and protects the printed circuit board from dust or foreign matter. In addition, PSR printing is a new method of improving the SR printing, and has the same function as SR printing in terms of insulation on the printed circuit board and protection of the printed circuit board. On the other hand, the marking process corresponds to a printing process of recording the name of each component on a printed circuit board coated with SR ink.

That is, in the process of applying PSR ink, a circuit and an insulator on the surface of the product are formed to protect the product, and a solder bridge between the circuit and the circuit is performed in a soldering process performed at the time of component mounting in a later process. This prevents the phenomenon from occurring.

On the other hand, at least one through hole or through hole via hole is formed in the printed circuit board, and the upper circuit and the lower circuit of the substrate are connected through the via hole. At this time, via holes are formed in the rigid or flexible substrate, and the via holes are filled by PSR or SR printing.

However, in the conventional printed circuit board, the via holes have substantially the same hole size on the upper and lower surfaces thereof. Accordingly, in the conventional printed circuit board, when the insulating material is filled by PSR or SR printing of the via hole, the via hole may be unfilled. In particular, in a reel to reel printed circuit board it may be a problem in the manner of filling the insulating material by vacuum adsorption.

The present invention provides a printed circuit board and a method of manufacturing the via hole formed in the substrate to improve the filling property of the insulating material of the via hole by forming a larger cross-sectional area on one surface than the cross-sectional area on one surface of the substrate. It aims to provide.

An aspect of the present invention includes a base substrate including at least one or more via holes penetrating both sides, wherein the via hole has a larger cross-sectional area at one surface of the base substrate than at another surface thereof, and the via hole is insulated. Provided is a printed circuit board filled with a material.

It is preferable that the cross-sectional area of the via hole is continuously reduced from one surface of the base substrate to the other surface.

It is preferable that the cross-sectional area of the via hole decreases stepwise from one surface of the base substrate to the other surface.

Preferably, the insulating material is PSR (Photo Solder Resist) or SR (Solder Resist).

Another aspect of the invention, (a) providing a base substrate; (b) forming at least one via hole through both surfaces of the base substrate; (c) plating the base substrate with a conductive material to form a plating layer; (d) forming a pattern of a passage through which electricity is conducted on the base substrate; And (e) applying an insulating material to the base substrate on which the plating layer is formed to form an insulating layer, wherein a cross-sectional area of one surface of the base substrate of the via hole is larger than that of another surface thereof, and (e) Provided is a method of manufacturing a printed circuit board in which the via hole is filled with the insulating material.

It is preferable that the via hole is formed by laser processing.

In the step (b), it is preferable to divide the via hole into at least two or more steps to form a deeper depth.

The step (c) preferably includes forming an electroless plating layer on the pattern by electroless plating, and forming an electrolytic plating layer on the electroless plating layer by electrolytic plating.

According to the present invention, the via hole formed in the substrate is formed to have a larger cross-sectional area on one surface than the cross-sectional area on one surface of the substrate, thereby improving the filling property of the insulating material of the via hole.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 and 2 respectively illustrate printed circuit boards according to the present invention, and each of the printed circuit boards 100 and 200 has a tapered via hole 111a and a stepped via hole 211a formed therein. At this time, in the printed circuit board 200 illustrated in FIG. 2, the via hole 211a is different from the printed circuit board 100 of FIG. 1 as a stepped shape.

Referring to the drawings, the printed circuit boards 100 and 200 include base substrates 110 and 210, plating layers 130 and 230, and insulating layers 140 and 240.

The base substrates 110 and 210 include at least one via hole 111a and 211a penetrating both surfaces. The plating layers 130 and 230 are formed by plating a conductive material on the base substrates 110 and 210. The insulating layers 140 and 240 are formed by coating an insulating material on the base substrates 110 and 210 on which the plating layers 130 and 230 are formed.

The via holes 111a and 211a are filled with an insulating material. In this case, the via holes 111a and 211a may be filled with an insulating material together when the insulating layers 140 and 240 are formed. The insulating layers 140 and 240 may be formed on one surface or both surfaces of the base substrates 110 and 210 on which the plating layers 130 and 230 are formed.

The insulating layers 140 and 240 form an insulating material on the surfaces of the base substrates 110 and 210 to protect the product, and solder between circuits and circuits in a soldering process that is performed during component mounting in a later process. (solder bridge) prevents the occurrence of the phenomenon.

The insulating material may be PSR (Photo Solder Resist) or SR (Solder Resist). In addition, a thermoplastic resin, an ultraviolet curable resin, a thermosetting resin, or the like may be used as the insulating material. Such resins may comprise a plain filler component.

The base substrates 110 and 210 include core substrates 111 and 211 and thin film layers 112 and 212. The core substrates 111 and 211 include at least one via hole 111a and 211a penetrating both surfaces. The core substrates 111 and 211 are insulating substrates, and may be laminates such as epoxy resins, cyanate resins, bisamareiamide triazine resins, polyamide resins, polyphenylene ether resins, glass fiber-containing or glass-containing laminates. And a film type insulating material may be used.

The thin film layers 112 and 212 are stacked and fixed on one or both surfaces of the core substrates 111 and 211, and are formed in a pattern in which electricity is conducted. At this time, the thin film layers 112 and 212 are preferably copper foil layers in which a material containing copper is formed into a thin film. The base substrates 110 and 210 may be copper foil laminated substrates on which copper foil layers are laminated and fixed on one or both surfaces of the core substrates 111 and 211.

The plating layers 130 and 230 are formed by plating a conductive material on the thin film layers 112 and 212. In this case, the plating layers 130 and 230 may electrically connect the circuit patterns 130a and 230a formed on one surface of the thin film layers 112 and 212 and the circuit patterns 130b and 230b formed on the other surface of the thin film layers 112 and 212. It is also preferably formed at 130c and 230c.

The via holes 111a and 211a may be through holes of a circular cross section formed through the base substrates 110 and 210. The via holes 111a and 211a may be processed by laser drilling. At this time, the laser used may be a carbon dioxide gas laser or ultraviolet laser.

The via holes 111a and 211a have larger cross-sectional areas on one surface of the base substrates 110 and 210 than those on the other surface. For this purpose, during laser drilling, it is preferable to select the laser energy and the number of shots so that the processing can be performed more at the center than at the periphery of the through holes formed at one surface of the base substrates 110 and 210.

In order to improve the filling property of the via holes 111a and 211a when filling the insulating material, the insulating material is preferably filled from one surface having a large cross-sectional area to the other surface having a small cross-sectional area. Do.

In the embodiment shown in FIG. 1, the via hole 111a gradually decreases from one surface of the base substrate 110 to the other surface thereof. In this case, the cross-sectional area of the via hole 111a may be reduced along a linear, quadratic function, or exponential function from one surface of the base substrate 110 to the other surface. That is, as shown in FIG. 1, the via hole 111a may be a tapered through hole in which the cross-sectional area decreases linearly from one surface to the other surface of the base substrate 110.

Since the via holes 111a of the printed circuit boards 100 and 200 of the present invention are formed with a larger cross-sectional area of one surface in the filling direction, the cross-sectional area of another surface of the printed circuit board 100 and 200 may be improved.

In the embodiment shown in FIG. 2, the cross-sectional area becomes stepwise smaller as the via hole 211a goes from one surface of the base substrate 210 to the other surface. The stepped shape of the via hole 211a can be processed while allowing the copper foil layer 212 of the lower copper to function as a barrier during laser processing.

In this case, when the insulating material is filled in the via hole 211a, the insulating material may be prevented from flowing downward. Therefore, the filling of the insulating material of the via hole 211a may be further improved.

When the via holes 111a and 211a have a diameter of one surface of 100 µm, the diameter of the other surface is preferably 50 µm or less, and the difference is 50 µm or more.

3 schematically shows a method (S300) of manufacturing the printed circuit boards 100 and 200 of FIGS. 1 and 2. 4 and 5 illustrate embodiments of forming the via holes 111a and 211a of FIG. 3, respectively. 4 illustrates a printed circuit board 100 including the tapered via hole 111a of FIG. 1, and FIG. 5 illustrates a printed circuit board 200 including the stepped via hole 211a of FIG. 2. It is.

Referring to the drawings, the method of manufacturing a printed circuit board S300 is a method of manufacturing the printed circuit boards 100 and 200 of FIGS. 1 and 2, and the description of each component is described with reference to FIGS. 1 and 2. Reference is made to the description of the illustrated printed circuit boards 100 and 200.

Method for manufacturing a printed circuit board (S300), (a) preparing a base substrate (S310); (b) forming at least one via hole (111a, 211a) penetrating both surfaces in the base substrate (110, 210) (S320); (c) plating the base substrate with a conductive material to form plating layers 130 and 230 (S330 and S340); (d) forming a pattern of a passage through which electricity is conducted to the base substrates 110 and 210 (S350); And (e) applying an insulating material to the base substrates 110 and 210 on which the plating layers 130 and 230 are formed to form the insulating layers 140 and 240 (S360).

In this case, it is preferable that the cross-sectional area of one surface of the base substrates 110 and 210 of the via holes 111a and 211a is larger than that of the other surface. When the insulating material is coated on the base substrates 110 and 210 in step (e), the via holes 111a and 211a may be filled with the insulating material.

The insulating material may be PSR (Photo Solder Resist) or SR (Solder Resist). In addition, a thermoplastic resin, an ultraviolet curable resin, a thermosetting resin, or the like may be used as the insulating material. Such resins may comprise a plain filler component.

The base substrates 110 and 210 include core substrates 111 and 211 and copper foil layers 112 and 212. The core substrates 111 and 211 may be rigid or flexible insulating substrates. The thin film layers 112 and 212 may be a copper foil layer in which a material containing copper is formed as a thin film. That is, the base substrates 110 and 210 may be copper foil laminated substrates on which copper foil layers 112 and 212 are laminated and fixed on one or both surfaces of the core substrates 111 and 211.

In the step (b) (S320), via holes 111a and 211a may be processed by laser drilling. At this time, the laser used may be a carbon dioxide gas laser or ultraviolet laser.

In the case of forming an ordinary cylindrical through-hole with a ultraviolet laser or the like, it can be executed by overlapping small laser processing spots, i.e., by trepanning processing. Meanwhile, the via holes 111a and 211a of the present invention may be formed by a similar tripping method.

The via holes 111a and 211a have larger cross-sectional areas on one surface of the base substrates 110 and 210 than those on the other surface. To this end, it is preferable to select the laser energy and the number of shots so that the processing may proceed more at the center than at the periphery of the through holes formed at one surface of the base substrates 110 and 210 during the UV laser processing.

At the time of laser processing, it is preferable to arrange an entry sheet or a backup sheet for laser processing on the upper or lower surface of the base substrates 110 and 210 for smooth progress of the work. Ultraviolet laser processing conditions are changed depending on the thickness of the workpiece or the thickness of the metal conductor, and is controlled by controlling the energy of one shot, the position of the shot, the number of shots, the total energy sum, and the like.

On the other hand, when via holes 111a and 211a are formed in the copper foil laminate using a carbon dioxide gas laser, a method of removing copper foil by etching in the via hole 111a and 211a forming portions and processing the copper foil laminate by laser irradiation, A through hole can be formed by a method of irradiating a laser or by irradiating a laser after arranging an entry sheet for laser processing to blacken or etch the copper surface. In order to form a tapered through hole, it is necessary to control the irradiation energy, the number of pulses, the mask diameter, and the like. In order to prevent damage to a machining table, a backup sheet for laser processing is arranged on the laser exit side.

In laser processing, a carbon dioxide gas laser and an ultraviolet laser may be used in combination. For example, after performing carbon dioxide gas laser processing, an ultraviolet laser can be used in order to form the opening part of a small diameter side.

In addition, when the via holes 111a and 211a are formed, as illustrated in FIGS. 4 and 5, the via holes 111a and 211a may be divided into at least two steps or more to deepen the depths. In FIGS. 4 and 5, the via holes 111a and 211a are processed in three steps, respectively.

Step (c) (S330, S340), the step of forming an electroless plating layer on the base substrate (110, 210) by electroless plating (S330), and forming an electrolytic plating layer on the electroless plating layer by electroplating It includes a step (S340). In step (d) (S350), a portion of the thin film layers 112 and 212 of the base substrates 110 and 210 may be etched to form a pattern that is a passage through which electricity is conducted.

According to the printed circuit board and the manufacturing method thereof according to the present invention, the via hole formed in the substrate is formed to have a larger cross-sectional area on one surface than the cross-sectional area on one surface of the substrate, thereby improving the fillability of the insulating material of the via hole. Can be.

Although the present invention has been described with reference to one embodiment shown in the accompanying drawings, this is merely exemplary, and various modifications and equivalent other embodiments may be made by those skilled in the art. You will understand. Accordingly, the true scope of protection of the invention should be defined only by the appended claims.

Claims (17)

A base substrate including at least one via hole penetrating both surfaces; The printed circuit board of claim 1, wherein the via hole has a larger cross-sectional area on one surface of the base substrate than the other surface, and the via hole is filled with an insulating material. The method of claim 1, And a cross-sectional area of the via hole continuously decreasing from one surface of the base substrate to the other surface. The method of claim 1, And a cross-sectional area of the via hole gradually decreases from one surface of the base substrate toward the other surface of the base substrate. The method according to claim 2 or 3, A printed circuit including an insulating core substrate including at least one via hole penetrating through both surfaces, and a thin film layer stacked and fixed on one or both surfaces of the core substrate and formed in an electrically conductive pattern; Board. The method of claim 4, wherein The printed circuit board of claim 1, wherein the thin film layer is a copper foil layer formed of a thin film. The method of claim 4, wherein The printed circuit board further comprises a plating layer formed by plating a conductive material on the thin film layer. The method of claim 6, The printed circuit board having the plating layer formed on the inner surface of the via hole. The method of claim 1, Printed circuit board wherein the insulating material is PSR (Photo Solder Resist) or SR (Solder Resist). (a) preparing a base substrate; (b) forming at least one via hole through both surfaces of the base substrate; (c) plating the base substrate with a conductive material to form a plating layer; (d) forming a pattern of a passage through which electricity is conducted on the base substrate; And (e) forming an insulating layer by coating an insulating material on the base substrate on which the plating layer is formed, And a cross-sectional area of the via hole on one surface of the base substrate is greater than that of the other surface, and in step (e), the via hole is filled with the insulating material. The method of claim 9, A printed circuit including an insulating core substrate including at least one via hole penetrating through both surfaces, and a thin film layer stacked and fixed on one or both surfaces of the core substrate and formed in an electrically conductive pattern; Method of manufacturing a substrate. The method of claim 10, The method of manufacturing a printed circuit board, wherein the thin film layer is a copper foil layer in which a material containing copper is formed of a thin film. The method of claim 9, The via hole is a manufacturing method of a printed circuit board formed by laser processing. The method of claim 9, And the via hole is processed such that its cross-sectional area is continuously reduced from one surface of the base substrate to the other surface. The method of claim 9, And a cross-sectional area of the via hole decreases stepwise from one surface of the base substrate to the other surface of the base substrate. The method according to claim 13 or 14, In the step (b), the via hole is divided into at least two or more steps to form a deeper and deeper printed circuit board manufacturing method. The method of claim 10, The step (c) includes the steps of forming an electroless plating layer by electroless plating on the pattern, and forming an electrolytic plating layer by electroplating on the electroless plating layer. The method of claim 9, Printed circuit board wherein the insulating material is PSR (Photo Solder Resist) or SR (Solder Resist).

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