JP2000232263A - Circuit board manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently manufacture a thinned circuit board by a method wherein electronic components are arranged on wiring parts, the components and the wiring parts are sealed with a resin and the wiring parts are separated from a base along with the components to complete the circuit board. SOLUTION: Wiring parts 11 are formed on a base 10 in a prescribed pattern, electronic components 12, such as a resistor and a capacitor, are mounted on the wiring parts 11 and the wiring parts 11 are cured by heating to fix the components 12 on the wiring parts 11. Then the base 10, the wiring parts 11 and the components 12 are housed in a frame body 13, a resin 14 is filled in the frame body 13 to cure the resin 14 and the wiring parts 11 and the components 12 are sealed with the resin 14. After that, the wiring parts 11 and the resin 14 are separated from the base 10 along with the components 12 to complete a circuit board 20. Thereby, the members for arranging and fixing the components 12 become unnecessary separately from the wiring pattern, and the whole circuit board 20 can be thinned.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circuit board in which passive elements and active elements are electrically connected by wiring portions.

[0002]

2. Description of the Related Art Conventionally, to mount electronic components on a board,
The procedure is as follows. First, electronic components are arranged on a substrate on which a predetermined wiring pattern is formed. Then, terminals such as leads and bumps of the electronic component are electrically connected by soldering to electrode portions such as through holes and lands formed in the wiring pattern and mounted.

However, according to the above-mentioned method, a substrate for arranging and fixing electronic components is required. In addition, solder and the like for arranging and fixing the electronic components are required, which is one of the factors that reduce the efficiency of the manufacturing operation. Furthermore, since the solder contains harmful lead, there is a problem that the environment may be harmed.

In recent years, attention has been paid to a circuit board having electronic components such as a resistor and a capacitor built therein. here,
A method for manufacturing a conventional circuit board 1 typified by JP-A-8-125313 will be described. First, as shown in FIG. 3A, a conductive adhesive 3 is applied on the metal conductor 2, and as shown in FIG. 3B, the electronic component 4 is arranged on the conductive adhesive 3. Is done. Then, the conductive adhesive 3 is heated and cured, and the electronic component 4 is mounted on the conductive adhesive 3.

[0005] Thereafter, as shown in FIG. 3 (C), a frame (not shown) is arranged around the metal conductor 2, and the resin is filled into the frame and solidified. Thereby, the electronic component 4 is sealed with the resin 5. Then, after the metal conductor 2 is detached from the frame, as shown in FIG.
A predetermined wiring pattern is formed by etching. Finally, as shown in FIG. 1F, unnecessary portions of the conductive adhesive 3 are removed by etching, and the circuit board 1 is completed.

[0006]

However, in the above-described manufacturing method, the metal conductor 2 forming the wiring pattern and the conductive adhesive 3 fixing the electronic component 4 are separately formed. For this reason, there is a problem that the thickness of the completed circuit board 1 is increased and the work efficiency cannot be improved. Further, the metal conductor 2 is formed in a wiring pattern by etching. Therefore, for example, when the metal conductor 2 is made of copper, a hazardous waste liquid is discharged at the time of etching, and there is a problem that the environment may be destroyed.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems and to provide a method of manufacturing a circuit board which can be thinned, environmentally friendly and efficiently manufactured.

[0008]

According to the first aspect of the present invention, a wiring portion made of a conductive adhesive is formed on a base in a predetermined wiring pattern, and an electronic component is arranged on the wiring portion. This is achieved by a method of manufacturing a circuit board, wherein the circuit section is fixed, the wiring section and the electronic component are sealed with resin, and the wiring section is peeled off from the base together with the electronic component to form a circuit board.

According to the configuration of the first aspect, the circuit board is manufactured by directly arranging and fixing the electronic component on the wiring portion forming the wiring pattern. This eliminates the need to use both the conductive adhesive for fixing the wiring portion and the electronic component as in the related art, thereby reducing the thickness of the circuit board and reducing the number of manufacturing steps. Further, since the wiring portion is formed on the base in a state where a predetermined wiring pattern is already formed, it is not necessary to perform etching for forming the wiring pattern, and it is possible to prevent generation of harmful substances due to etching. Can be.

[0010] According to a second aspect of the present invention, in the structure of the first aspect, the surface of the base on which the wiring portion is formed is formed by a method of manufacturing a circuit board having a rough surface. Achieved. According to the configuration of claim 2,
When the wiring portion and the resin are applied to the base, the surface on which the wiring portion and the resin are formed is roughened, so that the wiring portion and the resin are easily separated from the base.

[0011]

Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. Note that the embodiments described below are preferred specific examples of the present invention,
Although various technically preferable limits are given, the scope of the present invention is not limited to these modes unless otherwise specified in the following description.

FIG. 1 is a process chart showing a preferred embodiment of a method for manufacturing a circuit board according to the present invention. The method for manufacturing a circuit board will be described with reference to FIG. First, as shown in FIG. 1A, a base 10 made of a metal conductor is prepared, and is processed so that one end face 10a forming the wiring portion 11 is roughened. As a result, the wiring portion 11 can be
When the resin 14 is peeled off, the resin 14 can be easily peeled off. Then, as shown in FIG. 1B, the wiring portion 11 is formed on the one end surface 10a side of the base 10. At this time,
The wiring portion 11 is formed on the base 10 by, for example, a conductive adhesive in a predetermined pattern by screen printing or the like. This eliminates the need to perform etching when forming a wiring pattern as in the related art, and can prevent generation of harmful substances discharged by etching.

Next, as shown in FIG.
An electronic component 12 such as a resistor or a capacitor is mounted (mounted) on the wiring 1, and as shown in FIG.
1 is heated and cured, and the electronic component 12 is fixed. After that, as shown in FIG.
The electronic component 12 is accommodated in the frame 13, and the resin 13 is filled in the frame 13. When the resin 14 is cured, the electronic component 12 is sealed. next,
After the base 10 is taken out of the frame 13, FIG.
As shown in FIG. 5, the base 10, the wiring portion 11, and the resin 14 are peeled off. At this time, since the surface of the one end face 10a of the base 10 is rough, the wiring portion 11 and the resin 14 are easily peeled off. Then, a circuit board 20 as shown in FIG. 1 (G) is completed.

Here, FIG.
FIG. 3 is a plan view showing a wiring pattern of the wiring portion 11 when the resin 1 and the resin 14 are peeled off. In FIG. 2, the screen printed wiring portion 11 is built in the resin 14 side, and the pattern surface 11a is also flat. You can see that it is.

According to the above embodiment, since the electronic component 12 is arranged directly on the wiring portion 11, a member for arranging and fixing the electronic component 12 separately from the wiring pattern as in the related art is unnecessary, and the circuit board is not required. The circuit board 20 can be manufactured efficiently as the thickness of the circuit board 20 decreases. Also,
Since the wiring portion 11 forms a wiring pattern by screen printing or the like, generation of harmful substances due to etching can be prevented, and environmental pollution can be prevented. further,
Since the electronic component 12 is directly embedded in the resin 14, the entire circuit board 20 can be reduced in thickness, and vibration,
It is possible to provide one that is resistant to impact.

[0016]

As described above, according to the present invention,
It is possible to manufacture a circuit board efficiently and environmentally friendly while realizing the thinning.

[Brief description of the drawings]

FIG. 1 is a process chart showing a preferred embodiment of a method for manufacturing a circuit board of the present invention.

FIG. 2 is a plan view showing an electrode portion of the circuit board manufactured according to FIG. 1;

FIG. 3 is a process chart showing an example of a conventional method for manufacturing a circuit board.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Base, 11 ... Wiring part, 12 ... Electronic components, 13 ... Frame, 14 ... Resin, 20 ... Circuit board.

Claims (3)

[Claims] 1. A wiring portion made of a conductive adhesive is formed on a base in a predetermined wiring pattern, an electronic component is arranged and fixed on the wiring portion, and the wiring portion and the electronic component are sealed with a resin. And removing the wiring portion and the resin together with the electronic component from the base to form a circuit board. 2. The method according to claim 1, wherein a surface of the base on which the wiring portion is formed is formed as a rough surface. 3. The method according to claim 1, wherein the wiring portion is formed by screen printing.