KR20110066365A - Element having circuit pattern and buried printed circuit board using same and each fabrication method thereof - Google Patents

Abstract

PURPOSE: A circuit pattern forming member, embedded printed circuit board using the same, and method for manufacturing the same are provided to eliminate a conductive material filling process and a surface polishing process which need high technologies, thereby reducing defects of a circuit. CONSTITUTION: A Cu layer and a photosensitive agent are formed on a base board to form a member(S1). A circuit pattern is formed on the photosensitive agent(S2). A first circuit pattern is formed by isotropic etching. An etching mask is peeled off. Plating preprocessing is performed. A secondary circuit pattern is formed by electroplating. A circuit forming layer and an inner layer circuit are laminated by a press. An insulating layer is formed between the circuit forming layer and the inner layer circuit.

Description

ELEMENT HAVING CIRCUIT PATTERN AND BURIED PRINTED CIRCUIT BOARD USING SAME AND EACH FABRICATION METHOD THEREOF}

The present invention relates to a circuit pattern forming member, a buried printed circuit board using the same, and a manufacturing method thereof.

A printed circuit board (PCB) is a printed circuit board formed of a conductive material such as copper on an electrically insulating board, and refers to a board immediately before mounting an electronic component. That is, it means a circuit board which fixed the mounting position of each component, and printed and fixed the circuit line which connects components on the flat surface in order to mount many electronic components of various types densely on a flat plate.

As a technology to cope with the recent high density of semiconductor chips and high signal transmission speed, there is a demand for a technology for directly mounting a semiconductor chip on a printed circuit board instead of CSP (Chip-Sized Package) or wire bonding. Is growing. In order to directly mount a semiconductor chip on a printed circuit board, it is necessary to develop a high density and high reliability printed circuit board capable of coping with a higher density of semiconductors.

The requirements for high density and high reliability printed circuit boards are closely related to the specifications of semiconductor chips, and there are many problems such as miniaturization of circuits, high electrical characteristics, high speed signal transmission structure, high reliability, and high functionality. There is a need for a printed circuit board technology capable of forming a fine circuit pattern and a micro via hole corresponding to the requirements.

As a method for improving the reliability of the high-density pattern, a technique for the structure of embedding the via hole and the circuit pattern in the insulating layer is mainstream.

Two methods are widely used for filling via holes and circuit patterns.

First, there is a method of forming a final circuit by first implementing a circuit pattern, impregnating an insulating layer, and then removing a seed layer used to implement a circuit.

The second method is to form a mold having an embossed pattern having the same shape as the circuit pattern, to implement the intaglio pattern on the insulating layer, and then fill the intaglio pattern with a conductive material to form a final circuit pattern by surface polishing.

In the first method, in order to implement a buried pattern, a corresponding circuit pattern must be manufactured in advance, and the pattern is limited to one-time. In addition, the pre-fabricated circuit pattern is reduced in thickness from the bottom of the circuit pattern upward due to isotropic etching. As a result, when the pitch is reduced, the upper part of the circuit pattern collapses, so that there is a limit to the fine circuit formation.

Also, in order to solve the problem of fabricating the one-time circuit pattern, the second method is considered. The mold method allows one to manufacture many circuits of the same specification through one mold.

However, when the intaglio pattern is produced by the mold, it is required to have a high level of difficulty in filling the intaglio pattern with a conductive material, and surface polishing is used, thereby reducing the precision of the circuit.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a printed circuit board having improved density and reliability in a form in which a circuit is embedded in an insulating layer, and a method used for forming a circuit in general and at a cost. It is to provide a method using this inexpensive process and omitting the step of filling the conductive material of the existing process.

The circuit pattern forming member according to the present invention includes a circuit pattern layer formed on a base substrate, wherein the circuit pattern layer is composed of a copper circuit pattern portion narrowing toward an upper portion and a plating portion plated to surround the narrow portion. It is done.

In addition, the buried printed circuit board using the circuit pattern forming member according to the present invention, the insulating layer formed on the base substrate; And first and second circuit pattern layers embedded in upper and lower surfaces of the insulating layer, respectively, wherein the first circuit pattern layer is plated to surround the narrow portion and the copper circuit pattern portion that is narrowed toward the lower portion. The second circuit pattern layer may be formed of a copper circuit pattern portion that narrows toward the upper portion and a plated portion that is plated to surround the narrow portion.

In addition, a method of manufacturing a circuit pattern forming member according to the present invention is to (a) form a photosensitive agent on a copper layer formed on a base substrate, and then expose a copper layer portion corresponding to the circuit pattern through a photolithography process. step; (b) isotropically etching the exposed copper layer to form a copper circuit pattern portion that narrows toward the top; (c) peeling off the photosensitive agent; (d) plating the narrow portion of the copper circuit pattern portion to form a first circuit pattern layer.

Here, the step (b), after isotropic etching using one or more chemicals of iron chloride, copper chloride, alkali, may be washed and dried to form a copper circuit pattern portion narrowing toward the top.

The method may further include forming roughness on the surface of the copper circuit pattern layer or removing foreign matter between the steps (c) and (d).

In addition, the method for manufacturing a buried printed circuit board according to the present invention, (a) a member manufactured by the above-described printed circuit pattern forming member method, the inner layer circuit and the insulating layer having a second circuit pattern formed on the insulating substrate. Arranging the first and second circuit patterns so as to face each other; (b) compressing the member and the inner layer circuits to embed the first and second circuit patterns on the insulating layer; (c) removing the base substrate of the member.

Here, the buried printed circuit board manufacturing method includes (e) forming a via hole by drilling the insulating layer; And (f) plating the via hole to electrically connect the first circuit pattern and the second circuit pattern.

According to the present invention, it is possible to reduce the production cost by utilizing the existing proven process, it is possible to omit the step of filling the conductive material that requires a high level of technology. In addition, the circuit polishing rate can be reduced by eliminating the step of surface polishing the filled conductive material.

In addition, the circuit pattern produced by the present invention covers the narrow portion of the copper circuit pattern portion with a plating layer, so that the width of the entire circuit pattern does not gradually become narrow from the bottom, thereby forming a fine pattern.

Hereinafter, a circuit pattern forming member, a buried printed circuit board using the same, and a method of manufacturing each thereof will be described in detail with reference to the accompanying drawings. In the following description, well-known functions or constructions are not described in detail to avoid unnecessarily obscuring the subject matter of the present invention.

In the description of the embodiments, "on" and "under" include both directly and "indirectly" formed through other components. The reference to the above or below will be described with reference to the drawings, and the size of each component in the drawings may be exaggerated for the purpose of description and does not mean the size to which the circuit is actually applied. The pattern layer is referred to as being shortened.

1 is a block diagram showing a procedure of a circuit pattern forming member and a method of manufacturing a buried printed circuit board using the same according to a preferred embodiment of the present invention.

2 is a cross-sectional view of a manufacturing process of a circuit pattern forming member corresponding to each step of FIG. 1 and a buried printed circuit board using the same.

1 and 2, a member in which a Cu layer 120 and a photosensitive agent 130 are sequentially formed on a base substrate 110 is prepared (S1). Here, the base substrate 110 may be a copper substrate, and the photoresist 130 may be a dry film resist (DFR) or a photo resist (PR). In addition, a seed layer may be further formed between the base substrate 110 and the copper layer 120.

Thereafter, a circuit pattern is formed on the photosensitive agent 130 (S2). The circuit pattern is exposed and developed in the shape of the circuit pattern of the printed circuit board to be formed to form an etching mask 135. Next, a primary circuit pattern 140 is formed through isotropic etching (S3) (may be referred to as a copper circuit pattern portion). Specifically, isotropic corrosion of the copper layer 120 based on the bottom of the circuit is a circuit width to be implemented using a copper-specific corrosion agent, for example, iron chloride, copper chloride, alkali, etc. on the exposed and developed material. do. Thereafter, the first circuit pattern 140 is formed by washing and drying. As shown, the primary circuit pattern 140 becomes narrower toward the top due to isotropic etching, and thus becomes a pointed shape.

Next, the etching mask 135 is peeled off and the plating pretreatment process is performed (S4). The pretreatment process forms roughness on the surface of the primary circuit pattern 140 or removes foreign matter through a soft etching or polishing process. In addition, in the above-described step S1, when the seed layer is included, the step of removing the seed layer before peeling is included.

Thereafter, the electrode is applied to the primary circuit pattern 140 to form the secondary circuit pattern 150 through electrolytic plating (S5). More specifically, by forming a plating portion to surround a portion that becomes narrower toward the upper portion of the primary circuit pattern 140, the pointed portion of the primary circuit pattern 140 is widened.

As a result, the final circuit is formed by the secondary circuit pattern 150. Therefore, the shape of the primary circuit pattern 140, which is not suitable for forming the fine pattern, can be formed to be suitable for the final circuit pattern.

Up to this step is a circuit pattern forming member used for a printed circuit board. It reduces production costs by using the etching process using chemicals, which is an existing proven process, and omits the step of filling the conductive material, which requires a high level of technology. It can also be seen that the step of surface polishing the filled conductive material is omitted.

Hereinafter, a process of manufacturing a buried printed circuit board using the circuit pattern forming member will be described.

The circuit pattern forming member manufactured by the above process is aligned with the inner circuit with the insulating layer 160 interposed therebetween. Steps S1 to S5 may be used to form the inner layer circuit used herein. In addition, during the alignment, the base substrate 110 and the insulating substrate 170 face the outer shell, and the circuit pattern 150 of the circuit pattern forming member and the circuit pattern 180 of the inner layer circuit face each other. Thereafter, the circuit pattern forming member and the inner layer circuit are pressed into a press to embed the respective circuit patterns 150 and 180 in the insulating layer (S7). Thereafter, the base substrate 110 is removed to complete the buried printed circuit board (S8).

3 is a cross-sectional view illustrating a buried printed circuit board in which upper and lower circuit patterns are electrically connected through via holes.

Referring to FIG. 3, the photosensitive agent 190 is formed on the circuit pattern 150 exposed by the step S8 of FIG. 2 (S1). Thereafter, through the photolithography process, the photosensitive agent 190 portion of the portion to be exposed and developed to be punctured is removed (S2). In addition, the via layer 200 is formed by drilling the insulating layer 160, and a portion of the circuit pattern 180 on the insulating substrate 170 is exposed (S3). Next, the via hole 200 is filled with plating 210, and the upper and lower circuit patterns 150 and 180 are electrically connected to each other (S4). The photosensitive agent 190 is removed (S5). As a result, the embedded printed circuit board to which the upper and lower circuit patterns 150 and 180 are electrically connected can be manufactured without a high level of filling technique and surface polishing process.

In the foregoing detailed description of the present invention, specific examples have been described. However, various modifications are possible within the scope of the present invention. The technical spirit of the present invention should not be limited to the above-described embodiments of the present invention, but should be determined by the claims and equivalents thereof.

1 is a block diagram showing a procedure of a circuit pattern forming member and a method of manufacturing a buried printed circuit board using the same according to a preferred embodiment of the present invention.

FIG. 2 is a cross-sectional view of a manufacturing process of a circuit pattern forming member corresponding to each step of FIG. 1 and a buried printed circuit board using the same;

3 is a cross-sectional view of a buried printed circuit board in which upper and lower circuit patterns are electrically connected through via holes.

Description of the Related Art [0002]

110: base substrate 120: copper layer

130, 190 photoresist 135: etching mask

140: primary circuit pattern 150: secondary circuit pattern

160: insulating layer 170: insulating substrate

180: circuit pattern on the insulating substrate 200: via hole

210: via hole plating layer

Claims (7)

Including a circuit pattern layer formed on the base substrate, The circuit pattern layer is a circuit pattern forming member comprising a copper circuit pattern portion narrowing toward the upper portion and a plating portion plated to surround the narrow portion. An insulating layer formed on the base substrate; And The first and second circuit pattern layer embedded in the upper and lower surfaces of the insulating layer, respectively, The first circuit pattern layer is composed of a copper circuit pattern portion narrowing toward the lower portion and a plating portion plated to surround the narrow portion, The second circuit pattern layer is a buried printed circuit board, characterized in that consisting of a copper circuit pattern portion narrowing toward the upper portion and a plated portion plated to surround the narrow portion. (a) forming a photoresist on the copper layer formed on the base substrate, and then exposing a portion of the copper layer corresponding to the circuit pattern through a photolithography process; (b) isotropically etching the exposed copper layer to form a copper circuit pattern portion that narrows toward the top; (c) peeling off the photosensitive agent; (d) plating the narrow portion of the copper circuit pattern portion to form a first circuit pattern layer. The method of claim 3, In step (b), A method of manufacturing a circuit pattern forming member, comprising isotropic etching with at least one chemical agent of iron chloride, copper chloride, and alkali, followed by washing and drying to form a copper circuit pattern portion that narrows toward the top. The method of claim 3, Between steps (c) and (d), Forming a roughness or removing foreign matter on the surface of the copper circuit pattern portion further comprising a circuit pattern forming member manufacturing method. (a) arranging the member manufactured according to claim 3 so that the first and second circuit patterns face each other with the inner layer circuit having the second circuit pattern formed on the insulating substrate and the insulating layer interposed therebetween. (b) compressing the member and the inner layer circuits to embed the first and second circuit patterns on the insulating layer; (c) removing the base substrate of the member. The method of claim 6, The buried printed circuit board manufacturing method, (d) perforating the insulating layer to form via holes; And (e) plating the via hole, and electrically connecting the first circuit pattern and the second circuit pattern to each other.

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