JP2003298207A - Manufacturing method of double-side circuit board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of a double-side circuit board, by which a thin circuit board and high density mounting thereon can be preferably realized. <P>SOLUTION: Preparing an insulation base 2 having conductive layers 1, 3 on its both surfaces, through-holes 5 penetrating from its one conductor layer 1 to another conductor layer 3 are arranged in the insulation base 2. The through-holes 5 are filled with a conductive paste or a conductive ink to form conductor sections 6, and after grooves 7 needed for forming required wiring patterns are formed in the conductor layer 1, grooves 8 are formed utilizing the grooves 7 in the insulation base 2 by laser beam machining, plasma etching or wet etching. Wiring patterns 9 are formed by filling in the grooves 8 with the conductive paste or the conductive ink, and the remaining conductor layer 1 is removed. In the conductor layer 3, required wiring patterns are formed by a conventional method, or the required wiring patterns are filled and formed by applying above method. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a double-sided circuit board, and more particularly to a method for manufacturing a double-sided circuit board that can achieve a thin circuit board and high-density mounting.

[0002]

2. Description of the Related Art In recent years, miniaturization, weight reduction, and higher functionality of electronic equipment have been increasingly promoted. For this reason, the circuit board can be made thinner to support high-density mounting on the circuit board. And the demand for flattening is increasing.

Up to now, in the manufacturing process of the double-sided circuit board, a method using an NC drill or a mold has been widely adopted. However, with the recent trend toward higher density and finer circuit boards, fine via holes that cannot be achieved by these conventional methods have been demanded.

In order to form these minute through holes,
In recent years, a laser method using a carbon dioxide gas laser, a YAG laser, an excimer laser, or the like has been adopted, but the number of holes in a unit area increases because laser drilling is basically a single hole. However, there is a drawback that the productivity is deteriorated as a result.

Further, as a method for electrically connecting the first conductor layer and the second conductor layer by forming a conduction hole in the insulating material of the double-sided copper-clad plate, the first surface is positioned. After using a copper foil to form a mask layer having openings at required positions,
A method of forming a via hole by forming a conduction hole in the insulating layer by a plasma etching method or a wet etching method for the insulating layer and performing a conductive treatment and via hole plating has been adopted.

Although fine holes having a diameter of about 60 μm can be stably formed by using the laser processing, the plasma etching method, and the wet etching method, the circuit thickness is increased due to the increase in the conductor thickness due to the via hole plating. It has been difficult to thin and flatten the board by the conventional method for manufacturing a double-sided circuit board.

[0007]

DISCLOSURE OF THE INVENTION The present invention provides a method for suitably solving the above-mentioned problems of the conventional example, in which a material having conductor layers on both sides of an insulating base material is prepared. A conductive portion is formed from one conductor layer side at a position where mutual conduction is to be established in both conductor layers, and then a groove necessary for forming a wiring pattern is formed in the one conductor layer, After forming a groove in the insulating base material by laser processing, a plasma etching method, a wet etching method using this groove, a conductive paste or conductive ink is filled into the groove to form a wiring pattern, and the remaining A method for manufacturing a double-sided circuit board, which is characterized by removing one conductor layer, is adopted.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be further described below with reference to the illustrated embodiments. FIG. 1 is a manufacturing process diagram of a double-sided flexible circuit board according to an embodiment of the present invention. First, as shown in FIG. 1A, a material having conductor layers 1 and 3 on both surfaces of an insulating base material 2 such as a double-sided copper-clad plate is prepared.

Therefore, as shown in FIG. 2B, one conductor layer 1 is processed by etching to form a hole 4 for exposing a part of the insulating base material 2. The hole 4 is formed at a position where the conductor layer 1 and the other conductor layer 3 are electrically connected.

Next, as shown in FIG. 3C, using the conductor layer 1 having the holes 4 formed therein as a mask layer, the insulating base member 2 is subjected to laser processing, plasma etching method, and wet etching method to make holes. The conduction hole 5 is formed.

Thereafter, as shown in FIG. 4 (4), the conductive hole 5 formed is filled with a conductive paste or conductive ink to form a conductive portion 6 for conducting both the conductive layers 1 and 3.
Next, as shown in FIG. 5 (5), etching is performed again from the conductor layer 1 side to form the groove 7 necessary for a desired wiring pattern.
To form.

Therefore, the insulating base material 2 is formed by using the conductor layer 1 having the groove 7 as a mask layer as shown in FIG.
Then, groove processing is performed by laser processing, a plasma etching method, and a wet etching method to form the groove 8.

After that, a conductive pattern or conductive ink is filled in the groove 8 formed as shown in FIG. 7 (7) to form a wiring pattern 9, and then the remaining conductive layer 1 is removed by etching or polishing. Then, the conductive portion 10 is formed by polishing the surface and polishing and removing the upper end.

Further, by wiring the other conductor layer 3 as shown in FIG. 8 (8), the required wiring patterns 11 and 12 are formed to obtain a double-sided flexible circuit board.

Further, as shown in FIG. 2, by applying the above method to the conductor layers on both sides, the conductive portions 10 form wiring patterns 9, 13 and 14 which are partially conductive, so that both sides of the circuit board are flat. It is also possible to obtain a flexible double-sided circuit board.

[0016]

In the double-sided circuit board according to the present invention, a wiring pattern is formed by filling a conductive paste or the like into an insulating base material having holes and grooves formed on at least one surface of the circuit board. Since the surface of the circuit board is flattened, it is possible to suitably achieve thinning of the circuit board and high-density mounting, which were difficult with the conventional method for manufacturing a double-sided circuit board.

[Brief description of drawings]

FIG. 1 is a manufacturing process diagram of a double-sided flexible circuit board according to an embodiment of the present invention.

FIG. 2 is a double-sided flexible circuit of an example in which wiring patterns are filled on both sides according to the present invention.

[Explanation of symbols] 1 conductor layer 2 Insulating base material 3 conductor layers 4 holes 5 Conduction hole 6 Conducting part 7 groove 8 grooves 9 wiring patterns 10 Conducting part 11 wiring pattern 12 wiring patterns

Claims (2)

[Claims] 1. A material having conductor layers on both sides of an insulating base material is prepared, and a conducting portion is formed from one conductor layer side at a position where mutual conduction is to be established in both conductor layers, Then, a groove necessary to form a wiring pattern on the one conductor layer is formed, laser processing using this groove, a plasma etching method, after forming a groove in the insulating base material by a wet etching method, A method for producing a double-sided circuit board, characterized in that the groove is filled with a conductive paste or a conductive ink to form a wiring pattern, and the remaining one conductor layer is removed. 2. The method for manufacturing a double-sided circuit board according to claim 1, wherein the other side of the circuit board is filled with a conductive paste or conductive ink by the same method as described above to form a wiring pattern.