KR100807471B1 - Manufacturing method for printed circuit board - Google Patents

Abstract

A method for fabricating a printed circuit board is provided to reduce cost and enhance productivity by forming a solder-resist opening unit without a separate solder-resist opening process. A method for fabricating a printed circuit board(101) includes the steps of: providing the printed circuit board with a circuit pattern(103) including a pad unit(102) to install a semiconductor and to connect with an external component; providing a panel(104) having a pattern shape corresponding to the pad unit; stacking the panel on the printed circuit board after arranging the panel so as to place the pattern of the panel on the pad unit of the printed circuit board; applying and charging a liquid thermosetting solder-resist between the panel and the printed circuit board; forming a solder-resist layer(105) by thermally curing the solder-resist; and separating the panel from the printed circuit board and exposing the pad unit through a solder-resist opening unit.

Description

Manufacturing method for printed circuit board {Manufacturing method for printed circuit board}

1A to 1D are cross-sectional views schematically illustrating a manufacturing process flow of a printed circuit board according to an exemplary embodiment of the present invention.

2A to 2D are cross-sectional views schematically illustrating a manufacturing process flow of a printed circuit board according to an exemplary embodiment of the prior art.

※ Explanation of code about main part of drawing ※

101: printed circuit board 102: pad portion

103: circuit pattern 104: panel

105: solder resist layer 106: solder resist open portion

1: printed circuit board 2: pad part

3: circuit pattern 4: solder resist layer

5: dry film 6: artwork film

7: solder resist open part

The present invention relates to a method of manufacturing a printed circuit board. More specifically, the present invention relates to a method for manufacturing a printed circuit board which can improve design freedom with high productivity through a shortened process by forming a solder resist open portion and exposing a pad portion without a separate solder resist opening process. .

With the development of semiconductor chips, the speed at which electronic products are miniaturized, increased in density, and packaged is increasing. In accordance with this trend, printed circuit boards are also required to be densified and miniaturized. In order to mount a densified semiconductor chip, the connection pad portion connecting the semiconductor chip and the printed circuit board is miniaturized, and high precision alignment matching is required.

In this regard, the manufacturing process flow of the printed circuit board according to an embodiment of the prior art is schematically shown in Figures 2a to 2d, it will be described below with reference to this.

First, a printed circuit board having a circuit pattern 3 including a pad portion 2 for connection with semiconductor mounting and external components, manufactured according to the usual circuit forming process and build-up process, is produced (Fig. 2a). Subsequently, a conventional photosensitive solder resist is applied onto the substrate and then UV cured to form a solder resist layer 4 (see FIG. 2B). Next, a photoresist film, for example, a dry film 5, is applied on the solder resist layer 4, and the artwork film 6 designed according to the pattern shape to be formed is used (see FIG. 2C). After forming the solder resist open part 7 on the pad part 2 through a normal exposure and development process, the dry film 5 is peeled off (refer FIG. 2D).

However, in the method according to the related art, a very large number of processes are performed in order to form the solder resist open portion, which increases the manufacturing cost and increases the possibility of defects. In addition, the possibility of misalignment between the open area of the solder resist and the pad portion also increases, and there is a disadvantage in that design freedom is limited because a certain level or more gap is required between the pad portions to reduce the alignment error. .

Therefore, in the present invention, as a result of extensive research to solve the above problems, using a panel having a pattern shape corresponding to the pad portion on which the solder ball is to be mounted and the liquid thermosetting solder resist without a separate solder resist opening process The pad portion of the printed circuit board could be exposed, and the present invention was completed based on this.

Accordingly, an aspect of the present invention is to provide a method of manufacturing a printed circuit board which can form a solder resist open portion without a separate solder resist opening process.

Another aspect of the present invention is to provide a method for manufacturing a printed circuit board with high productivity through a shortened process.

Another aspect of the present invention is to provide a method of manufacturing a printed circuit board having a high degree of design freedom.

A method of manufacturing a printed circuit board according to one preferred embodiment of the present invention is:

(a) providing a printed circuit board having a circuit pattern including a pad portion for connecting the semiconductor mounting and external components;

(b) providing a panel having a pattern shape corresponding to the pad portion;

(c) arranging and stacking the panels so that the corresponding pattern of the panel is positioned on the pad portion of the printed circuit board;

(d) applying and filling a liquid thermosetting solder resist into a space between the panel and the printed circuit board;

(e) thermosetting the solder resist to form a solder resist layer; And

(f) separating the panel from the printed circuit board and exposing the pad portion through a solder resist open portion;

Characterized in that it comprises a.

According to the first embodiment, the panel may be made of a polymer material selected from the group consisting of polyurethane, polyester, silicone rubber, epoxy, polytetrafluoroethylene (PTFE), and combinations thereof. According to the second embodiment, the panel may be obtained by plating nickel on the surface of a polymer panel selected from the group consisting of polyurethane, polyester, silicone rubber, epoxy, PTFE, and combinations thereof. According to the third embodiment, the panel may be a nickel panel.

A release layer may be further formed on the pattern portion of the panel.

Meanwhile, lamination of step (c) and curing of step (e) may be preferably performed at the same temperature range, and the temperature range may be, for example, about 90 to 170 ° C.

The method may further comprise (g) secondary thermal curing the solder resist layer from which the panel is separated, wherein the curing temperature of step (e) and the curing temperature of step (g) are each from 90 to 90 ° C. 110 ° C. and 150-170 ° C.

1A to 1D schematically illustrate a manufacturing process flow of a printed circuit board according to an exemplary embodiment of the present invention. Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings.

First, a constant outer circuit pattern 103 comprising an inner layer and a pad portion 102 such as a wire bonding pad for semiconductor mounting and a soldering pad for coupling with an external component according to a conventional circuit forming process and a build-up process. A printed circuit board 101 is prepared (see FIG. 1A). In this figure, the detailed structure of the inner layer is omitted, and only the structure of the cross section of the printed circuit board is schematically illustrated, but the process according to the present invention may be performed on both surfaces. In addition, it is apparent that the number of circuit layers can be varied according to the application purpose, and the insulating resin and the metal for circuits used in each layer are not particularly limited, and any ones commonly used in the art can be used.

Meanwhile, a panel 104 having a pattern shape formed at a position corresponding to the pad portion 102 is prepared. The panel 104 is a material having good releasability and somewhat flexible material, and can be used without particular limitation as long as the panel 104 is made of a material that is usually used as a mold in an imprint process. As a preferred example, the panel may be one made of a polymer material of polyurethane, polyester, silicone rubber, epoxy, PTFE alone or in combination of two or more thereof. In addition, a panel in which nickel is plated on the surface of the polymer material may be used. Nickel panels are also available. The manufacturing method of such a panel is not particularly limited, and any method known in the art may be applied.

In the pattern portion of the panel 104, a conventional release layer may be further formed to facilitate panel separation in a subsequent process. The mold release agent used for forming the release layer is not particularly limited as long as it is usually applied to the mold surface of the imprint method. For example, conventional release agents such as epoxy, PTFE or silicone can be used.

The panel 104 fabricated as described above is positioned and stacked on the printed circuit board, and aligned so that the pattern of the panel 104 corresponding to the pad portion 102 of the printed circuit board is positioned, under a predetermined pressure and temperature. Lamination (see FIG. 2B). At this time, the pressure and temperature conditions are enough that the panel 104 and the printed circuit board does not fall. The lamination temperature may preferably be selected in the same range as the curing temperature of the subsequent process, for example, the temperature range may be about 90 ~ 170 ℃.

Subsequently, a liquid thermosetting solder resist 105 is applied, filled and cured in the space between the panel 104 and the printed circuit board to form a solder resist layer 105 that can protect the outermost layer of the substrate (Fig. 2c). In the present invention, the solder resist filling is performed in such a way that the resin flows into the empty space by capillary force after the resin is dispensed near the edge during filling of the resin in the underfill process. It can be charged according to this principle, and any method known in the art is not particularly limited and can be applied to anything.

Next, the panel 104 is separated from the printed circuit board to expose the pad portion 102 through the solder resist open portion 106 formed at the portion where the pattern portion of the panel 104 is located (see FIG. 2D).

Preferably, in the process of FIG. 2C, the solder resist is temporarily dried by primary curing, and after the separation of the panel, the secondary curing process is further performed to completely dry. At this time, the primary curing temperature is about 90 ~ 110 ℃ and the secondary curing temperature is preferably 150 ~ 170 ℃ in terms of workability and reliability. In addition, hardening time is although it does not specifically limit, For example, it may be about 30 to 60 minutes.

Meanwhile, a surface treatment layer for preventing corrosion may be further formed on the pad portion 102 exposed through the solder resist open portion 106 by selectively performing a conventional surface treatment as necessary. The surface treatment is not particularly limited as long as it is known in the art, for example, electrolytic gold plating, electroplating gold plating, organic solderability preservative or electroless tin plating (Immersion Tin Plating), Electroless Silver Plating, Direct Immersion Gold Plating, and Hot Air Solder Leveling (HASL). The pad part formed through the above process may be used as a pad for wire bonding or a pad for bumps or as a pad for solder bowl for mounting a solder ball.

As described above, according to the manufacturing method of the present invention, by applying a thermosetting solder resist in a state in which a panel is laminated on a substrate, a solder resist open portion is realized without a solder resist opening process through separate exposure and development, thereby simplifying a process compared to the existing process. This increases the productivity and the design freedom. In addition, the pad portion and the solder resist open portion may be formed to have the same area, thereby increasing design freedom.

Although the present invention has been described in detail through specific embodiments, this is for describing the present invention in detail, and the method of manufacturing a printed circuit board according to the present invention is not limited thereto, and the technical features of the present disclosure It is apparent that modifications and improvements are possible to those skilled in the art.

As described above, according to the present invention, a solder resist open portion may be formed to expose a pad portion without a separate solder resist opening process such as exposure, development, and drying, thereby reducing costs and improving productivity by shortening the number of processes. have. In addition, there is an advantage that can increase the design freedom as the area of the pad portion and the solder resist open portion match.

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

Claims (9)

(a) providing a printed circuit board having a circuit pattern including a pad portion for connecting the semiconductor mounting and external components; (b) providing a panel having a pattern shape corresponding to the pad portion; (c) arranging and stacking the panels so that the corresponding pattern of the panel is positioned on the pad portion of the printed circuit board; (d) applying and filling a liquid thermosetting solder resist into a space between the panel and the printed circuit board; (e) thermosetting the solder resist to form a solder resist layer; And (f) separating the panel from the printed circuit board and exposing the pad portion through a solder resist open portion; Method of manufacturing a printed circuit board comprising a. The method of claim 1, wherein the panel is made of a polymer material selected from the group consisting of polyurethane, polyester, silicone rubber, epoxy, polytetrafluoroethylene (PTFE), and combinations thereof. The method of claim 1, wherein the panel is formed by plating nickel on a surface of a polymer panel selected from the group consisting of polyurethane, polyester, silicone rubber, epoxy, PTFE, and a combination thereof. . The method of claim 1, wherein the panel is a nickel panel. The method of claim 1, wherein the panel further comprises a release layer on the pattern portion. The method of claim 1, wherein the lamination of step (c) and the curing of step (e) are performed at the same temperature range. The method of claim 6, wherein the temperature range is 90 to 170 ° C. 8. The method of claim 1, further comprising: (g) secondary thermal curing the solder resist layer from which the panel is separated. The method of claim 1, wherein the curing temperature of step (e) and the curing temperature of step (g) are 90 to 110 ° C. and 150 to 170 ° C., respectively.

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