KR100789533B1 - Printed circuit board for semi-conductor package and method of manufacturing the same - Google Patents

Abstract

A printed circuit board for a semiconductor package and a method for manufacturing the same are provided to simplify a solder resist forming process and a bump forming process by forming a bump using a metal tool having a specific pattern shape. A method for manufacturing a printed circuit board for a semiconductor package includes the steps of: preparing the printed circuit board for the semiconductor package including a circuit pattern and a pad part mounting a semiconductor and connecting with an outside components(S101); offering a metal tool placed for a pattern to correspond to the pad part, and having a base layer and the pattern formed on the top of the base(S102); attaching the pattern of the metal tool to one side or both sides of the printed circuit board to place the metal tool pattern corresponding to the pad part on the pad part(S103); charging and forming a solder resist layer in a space between the metal tool and the printed circuit board(S104); and patterning the base layer of the metal tool layer and forming a bump(S105).

Description

Printed circuit board for semi-conductor package and method of manufacturing the same}

1 is a flow chart showing a manufacturing process of a printed circuit board for a semiconductor package according to an embodiment of the prior art.

2A to 2F are cross-sectional views schematically illustrating a manufacturing process flow of a printed circuit board for a semiconductor package according to one embodiment of the prior art.

3 is a flowchart illustrating a manufacturing process of a printed circuit board for a semiconductor package according to an exemplary embodiment of the present invention.

4A to 4I are cross-sectional views schematically illustrating a manufacturing process flow of a printed circuit board for a semiconductor package according to an exemplary embodiment of the present invention.

※ Explanation of code about main part of drawing ※

11: first insulating resin layer 12: first circuit layer

13: 2nd insulating resin layer 14: 2nd circuit layer

15 solder resist layer 16 solder resist open portion

17 surface treatment layer 18 solder paste

19: solder ball

101: first insulating resin layer 102: first circuit layer

103: second insulating resin layer 104: second circuit layer

105: metal tool 106: solder resist

107: solder resist layer 108: photosensitive resist

109: photosensitive resist open portion 110: metal bump

111: surface treatment layer

The present invention relates to a printed circuit board for a semiconductor package and a method of manufacturing the same. More specifically, the present invention relates to a printed circuit board for a semiconductor package and a method of manufacturing the same, which can form bumps of fine pitch without misalignment between the open area of the solder resist and the bumps.

With the development of semiconductor chips, the speed at which many electronic products are miniaturized, densified, and packaged is increasing. In accordance with this trend, printed circuit boards are also required to be densified and miniaturized. In particular, in order to respond to rapid changes in the printed circuit board market and to lead the next-generation printed circuit board market while overcoming the technological gap with advanced companies, the flip chip (Flip® Chip) mounting semiconductor chip is directly mounted on the printed circuit board. There is an urgent need for technology.

In order to mount the densified semiconductor chip, it is required to refine the bumps connecting the semiconductor chip and the printed circuit board. However, current bump forming technology has a limitation in forming bumps having a fine pitch. Therefore, there is an urgent need for development of next-generation technologies for forming fine pitch bumps, and development of next-generation proprietary technologies is needed to demonstrate leadership in the printed circuit board industry.

In this regard, Figures 1 and 2a to 2f schematically illustrate the manufacturing process flow of a printed circuit board for a semiconductor package according to an embodiment of the prior art.

1 and 2, first, the first insulating resin layer 11, the first circuit layer 12, the second insulating resin layer 13, and the circuit according to a conventional circuit forming process and a build-up process. After fabricating a printed circuit board having an inner layer and an outer layer, such as a second circuit layer 14 including a pattern, pad portions for connecting semiconductor mounting and external components, and the like (S11, see FIG. 2A), on the substrate The solder resist layer 15 is formed (S12, see FIG. 2B), and only the pad portion 14 region is opened through a conventional solder resist opening process to form the solder resist opening portion 16 (see S13, FIG. 2C). ). Subsequently, a surface treatment layer 17 is formed on the pad portion 14 exposed through the solder resist opening portion 16 to prevent corrosion through normal surface treatment (S14, see FIG. 2D). After printing the solder paste 18 (S15, see FIG. 2E), a predetermined solder ball 19 is formed through a reflow and deflux process (S16, FIG. 2F).

However, when forming bumps such as solder balls by the method according to the related art, there are the following problems. That is, a lot of processes are performed to form solder resists and bumps, and as the number of processes proceeds, manufacturing costs increase and a possibility of defects increases. In addition, the possibility of misalignment between the open area of the solder resist and the bump is increased. Furthermore, when bumps having a fine pitch are formed by the conventional bump forming method, the possibility of electrical failure may increase due to coupling between adjacent bumps during reflow. Therefore, it is not possible to meet the requirements of the customer who wants a substrate in which fine pitch bumps are implemented.

Accordingly, in the present invention, as a result of extensive research to solve the above problems of the prior art, it was possible to form bumps of fine pitch using a metal tool having a predetermined pattern shape on a printed circuit board having an outermost layer. The present invention has been completed based on this.

Accordingly, an aspect of the present invention is to provide a printed circuit board for a semiconductor package and a method of manufacturing the same, which can simplify a conventional solder resist forming process and a bump forming process relatively.

Another aspect of the present invention is to provide a printed circuit board for a semiconductor package and a method of manufacturing the same, which have no alignment error between the open area of the solder resist and the bump.

Another aspect of the present invention is to provide a printed circuit board for a semiconductor package and a method of manufacturing the same, which can form bumps having a fine pitch that is difficult to cope with existing bump forming methods.

Method for manufacturing a printed circuit board for a semiconductor package according to an embodiment of the present invention:

(a) providing a printed circuit board for a package including a circuit pattern, the pad portion having a pad portion for connection with semiconductor components and external components;

(b) providing a metal tool having a base layer and a pattern formed thereon, wherein the metal tool is positioned such that the pattern corresponds to the pad portion;

(c) attaching a metal tool pattern on one or both sides of the printed circuit board such that the metal tool pattern corresponding to the pad part is positioned on the pad part;

(d) filling and forming a solder resist layer in a space between the metal tool and the printed circuit board; And

(e) patterning the base layer of the metal tool to form bumps;

Characterized in that it comprises a.

The metal of the metal tool is preferably selected from the group consisting of copper (Cu), nickel (Ni), aluminum (Al), silver (Ag), gold (Au), tin (Sn) and mixtures thereof.

The method may further comprise (f) forming a surface treatment layer for preventing corrosion on the bumps. The surface treatment layer forming step may be performed using electrolytic gold plating, electroplating gold, impurity gold plating, organic solderability preservative or electroless tin plating, and electroless silver plating. Plating), DIG plating (Direct Immersion Gold Plating) or Hot Air Solder Leveling (HASL). The thickness of the surface treatment layer is preferably 1 to 15 µm.

On the other hand, the solder resist is preferably a thermosetting solder resist.

In addition, when the metal tool is attached to one surface of the printed circuit board in the step (c), (i) forming a solder resist layer on a portion of the back surface of the printed circuit board except for the pad portion, and (ii) The forming of the surface treatment layer on the pad portion exposed through the solder resist layer may be further performed.

The printed circuit board for a semiconductor package according to an embodiment of the present invention is:

(a) a packaged printed circuit board having a pad portion for connecting to semiconductor mounting and external components, including a circuit pattern;

(b) a solder resist layer formed on one side or both sides of the printed circuit board except for the pad unit; And

(c) a metal bump formed on the solder resist layer, the pad portion exposed through the solder resist layer;

Characterized in that it comprises a.

Preferably, it further has a surface treatment layer formed on the metal bumps to prevent corrosion.

In addition, when the solder resist layer is formed on one surface of the printed circuit board, the back surface of the printed circuit board is (i) a solder resist layer formed on the portion excluding the pad portion, and (ii) a pad exposed through the solder resist layer. It further includes a surface treatment layer formed on the portion.

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

The requirements for printed circuit boards for semiconductor packages, especially flip chip mounting boards, are closely related to high speed and high density in the electronics industry market. To satisfy these requirements, circuit miniaturization, excellent electrical characteristics, high reliability, and high speed are required. Many problems, such as signal transmission structure and high functionalization, must be solved. The heat generation problem due to the high performance of the semiconductor chip is causing a large mechanical problem, and the direction of technology development is shifting to the concept of improving performance by adopting a multi-core structure as a means to solve this problem. As a result, the number of I / Os that deliver signals has increased significantly, and the necessity for the circuit density in the substrate on which the semiconductor chip is mounted to be greatly improved also increases. In addition, the pitch of the bumps connecting the substrate and the semiconductor chip is also minutely formed, which greatly increases the necessity of smoothly connecting signals between the semiconductor chip and the substrate.

Accordingly, the present invention provides a printed circuit board for a semiconductor package having a bump of a fine pitch and a method of manufacturing the same.

According to one preferred embodiment of the present invention, a metal tool having a pattern of a predetermined shape is attached to a substrate on which an outermost layer is formed, a solder resist is dispensed and cured, and then the metal tool is patterned through a conventional etching method to fine pitch. It is characterized by forming a bump.

In this regard, Figure 3 shows a flow chart of the manufacturing process of a printed circuit board for a semiconductor package according to an embodiment of the present invention.

Referring to FIG. 3, first, a printed circuit board having an inner layer and an outer layer formed according to a conventional circuit forming process and a buildup process is manufactured (S101). Subsequently, a metal tool having a predetermined pattern shape corresponding to the pad portion formed on the outer layer of the substrate is fabricated (S102) and attached to the substrate so that the pad portion and the corresponding pattern are attached to each other (S103). Next, a solder resist is filled and filled into the empty space between the metal tool and the substrate, for example, and then cured to form a solder resist layer (S104). Subsequently, the base layer of the metal tool is patterned according to a conventional exposure / development and etching method to form metal bumps (S105), and then the metal bumps are surface treated as necessary to form a surface treatment layer for protecting the bump surface. (S106).

Hereinafter, a method of manufacturing a printed circuit board for a semiconductor package according to an exemplary embodiment of the present invention will be described in more detail with reference to FIGS. 4A to 4I.

First, the first insulating resin layer 101, the first circuit layer 102, the second insulating resin layer 103, and the circuit pattern according to the conventional circuit forming process and build-up process known in the art, and semiconductor mounting And a printed circuit board on which an inner layer and an outer layer, such as the second circuit layer 104 including a pad portion for connection with an external component, are formed (see FIG. 4A). Although the four-layer printed circuit board is shown here as an example, the number of circuit layers can be varied depending on the application purpose. In addition, the insulating resin and the metal for the circuit used in the present invention are not particularly limited and may be used as long as it is commonly used in the art.

On the other hand, a metal tool 105 having a base layer and a pattern formed thereon is prepared (see FIG. 4B). At this time, the pattern of the metal tool 105 is formed at a position corresponding to the pad portion of the printed circuit board to be applied. The metal of the metal tool 105 is preferably an electrically conductive metal such as copper (Cu), nickel (Ni), aluminum (Al), silver (Ag), gold (Au), tin (Sn), and the like. It is selected from the group consisting of, and in addition to the metal that can be produced as a metal layer used in the art and mixtures thereof can be used without particular limitation. The manufacturing method of the metal tool is not particularly limited, but, for example, may be implemented in a predetermined range of fine pitch as desired through conventional exposure / development and etching methods. Although the thickness of the base layer of the metal tool manufactured as mentioned above is not specifically limited, It is preferable that the thickness of 10-60 micrometers mounts a semiconductor chip, and a printed circuit board and a semiconductor chip connect. The pattern specification of the metal tool corresponding to the pitch of the bumps to be formed later is not particularly limited, but the pitch between the patterns is 50 to 200 µm and the thickness of the pattern is 10 to 30 µm to fill and form the solder resist. Is preferred.

The metal tool 105 formed as described above is attached to the printed circuit board, and the pattern of the metal tool 105 corresponding thereto is attached to the pad 104 of the printed circuit board (see FIG. 4C). The attaching method may include, for example, simply aligning the printed circuit board and the metal tool, and then applying pressure to the metal tool to fix / connect the metal tool and the pad, and simply align the printed circuit board and the metal tool, and then A method of welding / fixing a pad and attaching a conductive adhesive (ACF) to the pattern end of the metal tool, aligning the printed circuit board and the metal tool, and then applying pressure to the metal tool. And a method of fixing / connecting the pad and the like, but are not particularly limited thereto.

Subsequently, the solder resist 106 is filled and cured in the space between the metal tool 105 and the printed circuit board to form a solder resist layer 107 that can protect the outermost layer of the substrate (FIGS. 4D and 4E). Reference). In the present invention, the solder resist filling is performed in such a manner that, for example, the resin is dispensed near the edge during filling of the resin in the underfill process, and then the resin naturally flows into the empty space by capillary force to be filled. According to this principle, as shown in FIG. 4D, the solder resist 106 may be dispensed and filled at the edge of the substrate. On the other hand, it is preferable to use a thermosetting solder resist as the solder resist for easier curing in structure.

Next, the photosensitive resist 108 is applied onto the base layer of the metal tool 105 (see FIG. 4F), and the photosensitive resist open portion 109 is applied to a portion except for the portion where the metal bump is to be formed through exposure / development. After forming (see FIG. 4G), the base layer of the metal tool 105 is etched using this as an etching resist to form bumps 110 of a predetermined shape (see FIG. 4H).

The bump 110 is optionally provided with a surface treatment layer 111 to prevent corrosion through a conventional surface treatment (see FIG. 4I). The surface treatment is not particularly limited as long as it is known in the art. Tin Plating, Immersion Silver Plating, Direct Immersion Gold Plating, Hot Air Solder Leveling, or the like. The thickness of the surface treatment layer 111 formed through such a process is preferably 1 to 15㎛ in terms of the efficiency of the desired effect expression.

In the above, a case in which the bump forming process is performed on both sides of the printed circuit board is described with reference to the drawings as an example. According to the present invention, the bump forming process as described above may be performed on one side or both sides of the printed circuit board. Can be. If the bump forming process described above is performed only on one surface of the printed circuit board, the solder resist layer is formed on the back surface of the printed circuit board except for the pad part, as is known in the art. The surface treatment layer may be formed on the exposed pad portion.

Although the present invention has been described in detail through specific embodiments, this is for explaining the present invention in detail, and the printed circuit board for a semiconductor package and the manufacturing method thereof according to the present invention are not limited thereto. It will be apparent to those skilled in the art that modifications and variations are possible.

As described above, according to the present invention, bumps are formed on a printed circuit board having an outermost layer by using a metal tool having a predetermined pattern shape, thereby relatively simplifying the existing solder resist forming process and the bump forming process, thereby reducing the fine pitch. Bumps can be formed. In addition, the alignment is always consistent between the open area of the solder resist and the bumps.

Furthermore, according to the present invention, there is an advantage that it is possible to form a bump of a fine pitch difficult to cope with the existing bump forming method. In addition, since the metal tool fabricated to have a predetermined pattern corresponding to the bump is applied, there is almost no scale deviation, and thus the bump forming process can be performed at a time even on a panel having a size of 510 × 610 mm or less, which is economical.

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 (12)

(a) providing a printed circuit board for a package including a circuit pattern, the pad portion having a pad portion for connection with semiconductor components and external components; (b) providing a metal tool having a base layer and a pattern formed thereon, wherein the metal tool is positioned such that the pattern corresponds to the pad portion; (c) attaching a metal tool pattern on one or both sides of the printed circuit board such that the metal tool pattern corresponding to the pad part is positioned on the pad part; (d) filling and forming a solder resist layer in a space between the metal tool and the printed circuit board; And (e) patterning the base layer of the metal tool to form bumps; Method of manufacturing a printed circuit board for a semiconductor package comprising a. The metal of claim 1, wherein the metal of the metal tool is selected from the group consisting of copper (Cu), nickel (Ni), aluminum (Al), silver (Ag), gold (Au), tin (Sn), and mixtures thereof. Method of manufacturing a printed circuit board for a semiconductor package, characterized in that the. The method of claim 1, wherein the method further comprises (f) forming a surface treatment layer for preventing corrosion on the bumps. The method of claim 3, wherein the forming of the surface treatment layer is performed by electrolytic gold plating, electroless gold plating, organic solderability preservative, or electroless tin plating. A method of manufacturing a printed circuit board for a semiconductor package, characterized in that. The method of manufacturing a printed circuit board for a semiconductor package according to claim 3, wherein the surface treatment layer has a thickness of 1 to 15 µm. The method of claim 1, wherein the solder resist is a thermosetting solder resist. The method of claim 1, wherein when the metal tool is attached to one surface of the printed circuit board in the step (c), (i) forming a solder resist layer on the back surface of the printed circuit board except for the pad portion, and and (ii) forming a surface treatment layer on the pad portion exposed through the solder resist layer. (a) a packaged printed circuit board having a pad portion for connecting to semiconductor mounting and external components, including a circuit pattern; (b) a solder resist layer formed on one side or both sides of the printed circuit board except for the pad unit; And (c) a metal bump formed on the solder resist layer, the pad portion exposed through the solder resist layer; Printed circuit board for a semiconductor package comprising a. The metal of the metal bump is selected from the group consisting of copper (Cu), nickel (Ni), aluminum (Al), silver (Ag), gold (Au), tin (Sn) and mixtures thereof. Printed circuit board for a semiconductor package, characterized in that the. The printed circuit board of claim 8, further comprising a surface treatment layer formed on the metal bumps to prevent corrosion. The printed circuit board of claim 10, wherein the surface treatment layer has a thickness of 1 to 15 μm. The method of claim 8, wherein when the solder resist layer is formed on one surface of the printed circuit board, the back surface of the printed circuit board may include (i) a solder resist layer formed on a portion other than the pad part, and (ii) the solder resist layer. The printed circuit board for a semiconductor package, further comprising a surface treatment layer formed on the exposed pad portion.

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