JP2013080889A - Printed circuit board and manufacturing method of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a printed circuit board for improving problems such as lifting of a seed layer due to the deterioration of the adhesion force between a solder resist and the seed layer and the damage of the solder resist, and to provide a manufacturing method of the printed circuit board.SOLUTION: A manufacturing method of a printed circuit board 100 of this invention includes the steps of: preparing a base substrate 110 where a circuit layer 120 including a connection pad 121 and a circuit pattern 123 is formed; forming a solder resist layer 130, having a first opening from which the connection pad 121 is exposed, on the base substrate 110 including the circuit layer 120; forming a plating resist layer, having a second opening at a region corresponding to the first opening, on the solder resist layer 130; forming the seed layer 150 on the plating resist layer so as to include the first and second openings; and forming a metal post 170 at the first and second openings.

Description

  The present invention relates to a printed circuit board and a method for manufacturing the same.

  As disclosed in Patent Document 1, the development of a metal post-bumping technique has been proposed as a next-generation bumping technique that can overcome the pitch limit and reliability of solder bumps in a fine pitch.

  However, the above-mentioned metal post has the advantage that the post height can be formed high so that it can cope with fine pitches, while the adhesion with the seed layer formed on the solder resist is inferior. A point is generated.

  In order to improve the above-described problem, a technique for forming a surface roughness on a solder resist has been proposed. However, this technique has a problem in that the solder resist is damaged.

  Due to the problems associated with the solder resist described above, there is a problem that the process after the solder resist is formed becomes difficult.

Korean Published Patent No. 2010-0060968

  The present invention is for solving the above-mentioned problems of the prior art, and one aspect of the present invention is that a seed generated by a decrease in adhesion between a solder resist and a seed layer when forming a metal post. It is an object of the present invention to provide a printed circuit board and a method for manufacturing the printed circuit board for improving problems such as layer floating and solder resist damage.

  A method of manufacturing a printed circuit board according to an embodiment of the present invention includes preparing a base substrate on which a circuit layer including a connection pad and a circuit pattern is formed, and the connection pad on the base substrate including the circuit layer. Forming a solder resist layer having an exposed first opening; and forming a plating resist layer having a second opening in a region corresponding to the first opening on the solder resist layer; The method includes a step of forming a seed layer on the plating resist layer including the first and second openings, and a step of forming a metal post in the first and second openings.

  Here, forming the metal post includes forming the metal layer on the plating resist layer including the first and second openings, the seed layer formed on the plating resist layer, and Removing the metal layer.

  Preferably, the method further includes a step of removing the plating resist layer after the step of removing the metal layer.

  The plating resist layer is preferably a dry film in the step of forming the plating resist layer.

  In addition, in the step of forming the seed layer, a seed is formed on the upper portion of the connection pad exposed through the first and second openings, the inner wall of the first and second openings, and the upper portion of the plating resist layer. It is preferable to form a layer.

  In the step of forming the metal post, the metal post is preferably made of copper.

  A printed circuit board according to another embodiment of the present invention is formed on a base substrate on which a circuit layer including connection pads and a circuit pattern is formed, and the connection pads are exposed on the base substrate including the circuit layer. A solder resist layer having an opening formed as described above, a metal post formed in the opening, and a seed layer formed on a side surface of the metal post including the opening.

  Here, it is preferable that the seed layer is formed in the opening and part of a side surface of the metal post.

  The metal post is preferably made of copper.

  The features and advantages of the present invention will become more apparent from the following detailed description taken in conjunction with the accompanying drawings.

  Prior to the detailed description of the invention, the terms and words used in the specification and claims should not be construed in a normal and lexicographic sense, and the inventor shall best understand his invention. It should be construed as meanings and concepts in accordance with the technical idea of the present invention in accordance with the principle that the concept of terms can be appropriately defined to describe the method.

  In the printed circuit board and the manufacturing method thereof according to the present invention, since the seed layer is formed after the formation step of the solder resist layer and the plating resist layer, which is immediately before the metal post is formed, the solder resist layer and the seed layer are formed. It can be expected that the seed layer floating phenomenon that occurs due to the decrease in adhesion can be prevented.

  In addition, the present invention minimizes the contact area between the solder resist layer and the seed layer, thereby eliminating the step of forming the surface roughness of the solder resist to improve the adhesion between the solder resist and the seed layer. Therefore, the solder resist can be prevented from being damaged.

It is sectional drawing which shows the structure of the printed circuit board by the Example of this invention. It is process sectional drawing for demonstrating the manufacturing method of the printed circuit board of FIG. It is process sectional drawing for demonstrating the manufacturing method of the printed circuit board of FIG. It is process sectional drawing for demonstrating the manufacturing method of the printed circuit board of FIG. It is process sectional drawing for demonstrating the manufacturing method of the printed circuit board of FIG. It is process sectional drawing for demonstrating the manufacturing method of the printed circuit board of FIG. It is process sectional drawing for demonstrating the manufacturing method of the printed circuit board of FIG. It is process sectional drawing for demonstrating the manufacturing method of the printed circuit board of FIG. It is sectional drawing which shows the structure of the printed circuit board by the other Example of this invention.

  Objects, specific advantages and novel features of the present invention will become more apparent from the following detailed description and preferred embodiments when taken in conjunction with the accompanying drawings. In this specification, it should be noted that when adding reference numerals to the components of each drawing, the same components are given the same number as much as possible even if they are shown in different drawings. I must. Further, in describing the present invention, when it is determined that a specific description of the related art related to the present invention may obscure the gist of the present invention, a detailed description thereof will be omitted. In this specification, terms such as “first” and “second” are used to distinguish one component from another component, and the component is not limited by the term.

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

(Printed circuit board)
FIG. 1 is a cross-sectional view illustrating a configuration of a printed circuit board according to an embodiment of the present invention, and FIG. 9 is a cross-sectional view illustrating a configuration of a printed circuit board according to another embodiment of the present invention.

  As shown in FIG. 1, the printed circuit board 100 is formed on a base substrate 110 on which a circuit layer 120 including connection pads 121 and a circuit pattern 123 is formed, and on the base substrate 110 including the circuit layer 120. A solder resist layer 130 having an opening formed to expose 121; a metal post 170 formed in the opening; and a seed layer 150 formed on a side surface of the metal post including the opening. It is a waste.

  On the other hand, as shown in FIG. 9, the seed layer 150 is formed on the side surface of the metal post 170 including the opening, but is preferably formed on a part of the side surface of the metal post 170.

  The metal post 170 is preferably made of copper, but is not limited thereto.

  The base substrate 110 is a circuit board in which one or more circuits including connection pads are formed in an insulating layer, and is preferably a printed circuit board. In this drawing, for the convenience of explanation, the configuration of a specific inner layer circuit is omitted, but a person skilled in the art has formed one or more circuits in an insulating layer as the base substrate 110. It will be appreciated that it can be applied to normal circuit boards.

  As the insulating layer, a resin insulating layer is preferably used. As the resin insulating layer, it is preferable to use a thermosetting resin such as an epoxy resin, a thermoplastic resin such as polyimide, or a resin impregnated with a reinforcing material such as glass fiber or inorganic filler, such as a prepreg, Moreover, although it is also preferable to use a photocurable resin etc., it is not specifically limited to these.

  The circuit layer including the connection pads 121 and the circuit pattern 123 can be applied without limitation as long as it is used as a conductive metal for circuits in the field of circuit boards. In a printed circuit board, copper is used. It is common to use.

  The solder resist layer 130 functions as a protective layer for protecting the outermost layer circuit and is formed for electrical insulation. In order to expose the outermost connection pad 121, an opening portion is formed. It is formed. The solder resist layer 130 is preferably composed of, for example, a solder resist ink, a solder resist film, or a sealant, as known in the art, but is not particularly limited thereto.

  It is preferable that a surface treatment layer (not shown) is further formed on the exposed connection pads 121 as necessary.

  The surface treatment layer is not particularly limited as long as it is known in the art. For example, the surface treatment layer may be, for example, electrolytic gold plating, electroless gold plating, OSP (Organic Solderability Preservative). ), Electroless tin plating (Immersion Tin Plating), electroless silver plating (Immersion Silver Plating), ENIG (Electroless Nickel and Immersion Gold), DIG plating (Direct Immersion Gold, Gold Immersion Gold) Hot Air Solder Level ng) or the like.

(Printed circuit board manufacturing method)
2 to 8 are process cross-sectional views for explaining a method of manufacturing the printed circuit board of FIG.

  First, as illustrated in FIG. 2, a base substrate 110 on which a circuit layer 120 including connection pads 121 and a circuit pattern 123 is formed is prepared.

  Here, the base substrate 110 is a circuit board in which one or more layers of circuits including connection pads are formed in an insulating layer, and is preferably a printed circuit board. In this drawing, for the convenience of explanation, the configuration of a specific inner layer circuit is omitted, but a person skilled in the art has formed one or more circuits in an insulating layer as the base substrate 110. It will be appreciated that it can be applied to normal circuit boards.

  As the insulating layer, a resin insulating layer is preferably used. As the resin insulating layer, a thermosetting resin such as an epoxy resin, a thermoplastic resin such as polyimide, or a resin impregnated with a reinforcing material such as glass fiber or inorganic filler, for example, a prepreg can be used. Moreover, although it is also preferable to use a photocurable resin etc., it is not specifically limited to these.

  Next, as illustrated in FIG. 2, a solder resist layer 130 having a first opening 131 through which the connection pad 121 is exposed is formed on the base substrate 110 including the circuit layer 120.

  The solder resist layer 130 is preferably composed of, for example, a solder resist ink, a solder resist film, or a sealant, as known in the art, but is not particularly limited thereto.

  Next, as illustrated in FIGS. 3 and 4, a plating resist layer 140 having a second opening 141 in a region corresponding to the first opening 131 is formed on the solder resist layer 130.

  At this time, the plating resist layer 140 is preferably made of a photosensitive resist such as a dry film or a liquid positive photoresist (P-LPR), but is not limited thereto.

  Next, as shown in FIG. 5, a seed layer 150 is formed on the plating resist layer 140 including the first and second openings 131 and 141.

  At this time, the seed layer 150 is formed on the connection pad 121 exposed through the first and second openings 131 and 141, the inner walls of the first and second openings 131 and 141, and the plating resist layer 140. It is preferable to form.

  As described above, in the present invention, in the seed layer 150, the contact area between the seed layer 150 and the plating resist layer 140 is larger than the contact area between the seed layer 150 and the solder resist layer 130 having weak adhesion to the seed layer 150. It can be expected that the seed layer can be prevented from being lifted due to a decrease in the adhesion between the resist layer and the seed layer.

  Further, by improving the adhesion between the seed layer 150 and the plating resist layer 140, the step of forming the surface roughness on the solder resist layer 130 to improve the adhesion with the seed layer can be omitted. Therefore, it can be expected that the process is simplified and the solder resist layer is prevented from being damaged.

  Further, the seed layer 150 may include, for example, a degreasing process, a soft etching process, a pre-catalyst process, a catalyst process, an activation process, an electroless plating process, and Although it is preferable to form using the general catalyst precipitation system including an antioxidant treatment process, it is not limited to these.

  Next, as illustrated in FIGS. 6 and 7, a metal post 170 is formed in the first and second openings 131 and 141.

  More specifically, forming the metal post 170 includes forming the metal layer 160 on the plating resist layer 140 including the first and second openings 131 and 141, and forming the metal post 170 on the plating resist layer 140. Removing the seed layer 150 and the metal layer 160 formed.

  At this time, the step of forming the metal layer 160 on the plating resist layer 140 is a step of forming the metal layer 160 substantially on the seed layer 150 formed on the plating resist layer 140.

  The seed layer 150 is preferably removed by quick etching or flash etching.

  As shown in FIG. 7, when the seed layer 150 and the metal layer 160 are removed, the seed layer and the first and second openings 131 and 141 formed on the inner walls of the first and second openings 131 and 141 are formed. The formed metal posts 170 are left, and the seed layer 150 and the metal layer 160 formed on the plating resist layer 140 are removed.

  In addition, it is preferable to further perform a step of removing the plating resist layer 140 after the step of removing the metal layer 160.

  At this time, the plating resist layer 140 is preferably removed using a stripping solution such as sodium hydroxide (NaOH) or potassium hydroxide (KOH).

  The metal post 170 is preferably made of copper, but is not limited thereto.

  The present invention has been described in detail on the basis of the specific embodiments. However, this is for specifically explaining the present invention, and the printed circuit board and the method for manufacturing the same according to the present invention are described here. It will be apparent to those skilled in the art that the present invention is not limited and that modifications and improvements can be made within the technical idea of the present invention.

  All simple variations and modifications of the present invention belong to the scope of the present invention, and the specific scope of protection of the present invention will be apparent from the appended claims.

  The present invention can be applied to a printed circuit board and a method of manufacturing the printed circuit board for improving problems such as floating of the seed layer caused by a decrease in adhesion between the solder resist and the seed layer and damage to the solder resist.

DESCRIPTION OF SYMBOLS 100 Printed circuit board 110 Base board 120 Circuit layer 121 Connection pad 123 Circuit pattern 130 Solder resist layer 131 1st opening part 140 Plating resist layer 141 2nd opening part 150 Seed layer 160 Metal layer 170 Metal post

Claims (9)

Preparing a base substrate on which a circuit layer including connection pads and a circuit pattern is formed;
Forming a solder resist layer having a first opening from which the connection pad is exposed on the base substrate including the circuit layer;
Forming a plating resist layer having a second opening in a region corresponding to the first opening on the solder resist layer;
Forming a seed layer on the plating resist layer, including the first and second openings;
Forming a metal post in the first and second openings;
Of manufacturing a printed circuit board. Forming the metal post comprises:
Forming a metal layer on the plating resist layer, including the first and second openings;
Removing the seed layer and the metal layer formed on the plating resist layer;
The manufacturing method of the printed circuit board of Claim 1 containing this. After the step of removing the metal layer,
The method of manufacturing a printed circuit board according to claim 2, further comprising removing the plating resist layer.   The method of manufacturing a printed circuit board according to claim 1, wherein in the step of forming the plating resist layer, the plating resist layer is a dry film.   In the step of forming the seed layer, a seed layer is formed on the connection pad exposed through the first and second openings, the inner walls of the first and second openings, and the plating resist layer. The manufacturing method of the printed circuit board of Claim 1 which forms.   The method of manufacturing a printed circuit board according to claim 1, wherein in the step of forming the metal post, the metal post is made of copper. A base substrate on which a circuit layer including connection pads and a circuit pattern is formed;
A solder resist layer formed on the base substrate including the circuit layer and having an opening formed to expose the connection pads;
A metal post formed in the opening;
A seed layer formed on a side surface of the metal post including the opening;
Including printed circuit board.   The printed circuit board according to claim 7, wherein the seed layer is formed in the opening and is formed on a part of a side surface of the metal post.   The printed circuit board according to claim 7, wherein the metal post is made of copper.

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