JPH118464A - Manufacture of circuit board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide easy and accurate cutting and removal of connection parts which are prevent partial conductors from disassembling, and to cover the end surfaces of the cut and removed parts with a resin in the manufacturing process of a circuit board which has conductor patterns embedded in the resin. SOLUTION: A conductor foil material is pressed or etched to form a circuit conductor pattern conductor 1 with a plurality of partial conductors 1a, 1b and 1c which are to be independent conductors, so as to leave connection parts 2 between the partial conductors adjacent to each other in order to prevent the partial conductors 1a, 1b and 1c from disassembling. After an insulating film 9 is stuck to one surface of the circuit pattern conductor 1, the connection parts 2 are cut and removed with the corresponding parts of the insulating film to electrically isolate the partial conductors. Finally, the circuit pattern conductor 1 and the insulating film 9 are covered with a covering resin 12, while the necessary parts of the circuit pattern conductor 1 are exposed.

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 circuit board on which electronic components are mounted to form a circuit.

[0002]

2. Description of the Related Art In recent years, electronic equipment has been improved in performance and function, and there has been a demand for lighter, thinner and smaller products. 2. Description of the Related Art A circuit board on which electronic components are mounted has a structure in which a conductor on which a circuit pattern is formed is embedded in a resin. FIG. 3 shows a method of manufacturing a conventional circuit board of this type, wherein 1 denotes a conductor on which a circuit pattern is formed (hereinafter referred to as a circuit pattern conductor), and 1a, 1b, and 1c denote individual circuit patterns. Conductor (hereinafter referred to as a partial conductor), 2 is a joint, 3
Is a gap between partial conductors, 4 is a resin, 5 is a joint cavity, 6 is a component mounting portion, 7 is a cut portion, and 8 is a cut piece.

Next, a method of manufacturing the circuit board will be described. Note that, here, the partial conductors 1a, 1b, 1c constituting the circuit pattern are displayed as simple patterns such as rectangles for easy understanding. However, in actual cases, the circuit conductors have more complicated circuit patterns. The gap between partial conductors is also small,
Needless to say, it has various shapes.

First, in FIG. 3 (a), the conductor foil material is press-processed or left with the joining portion 2 left so that the plurality of partial conductors 1a, 1b, 1c, which are to be finally separated independently, do not separate apart. The circuit pattern conductor 1 is formed by etching. A gap 3 is formed between the partial conductors.

In FIG. 3B, the circuit pattern conductor 1 is put into a molding die, a resin is injected, and the circuit pattern conductor 1 is covered with a resin 4. In this case, the coupling portion cavity 5 is formed in the coupling portion 2, and the resin-free component mounting portion 6 is formed in the component mounting portion so that the circuit pattern conductor 1 is exposed.

The resin coating may be a single-sided coating or a partial coating, in addition to covering the entire circuit pattern conductor 1.
In any method, no resin is formed on the joint portion 2 and the component mounting portion 6 which are cut off later.

Next, in FIG. 3C, the joint 2 is cut off by press working or another method. That is, the partial conductor 1
The partial conductors 1a, 1b, 1b, 1c are cut off by cutting off the joint portion 2 which has been stopped so that the a, 1b, 1c do not separate apart.
1c is separated into individual electrically independent conductor portions to form predetermined circuit conductors.

[0008]

However, in the above-described conventional manufacturing method, the cutout portion 7 has a cut end surface of the conductor exposed, and an unexpected situation such as an electrical short circuit occurs.
In the case of a high-voltage circuit, there is a problem that a large space must be secured in order to obtain a predetermined insulation distance. Therefore, in a later step, the cutout 7 must be filled with an insulator, which causes insufficient filling or leakage, and since the conductor is located in the middle of the thickness of the substrate, it is difficult to cut the conductor. If the resin is left protruding from the resin surface or if the resin around the joint is cut together to avoid this protrusion, unnecessary force is applied to the resin, causing chipping or cracking, resulting in the reliability of the circuit board. Had the problem of impairing the performance.

The present invention has been made in view of the above-mentioned problems of the prior art, and provides a method of manufacturing a circuit board capable of reliably and easily cutting a joint portion and covering the cut end surface with a resin in the process of manufacturing the circuit board. The purpose is to:

[0010]

In order to achieve the above object, a method of manufacturing a circuit board according to the present invention is to provide a method of manufacturing a circuit board, comprising: temporarily fixing a partial conductor with an insulating material; To complete the circuit board.

Therefore, according to the present invention, a conductor foil material is pressed by leaving a joint at an arbitrary position between adjacent partial conductors so that a plurality of partial conductors which are to be individually independent are not decomposed. Or a step of forming a circuit pattern conductor by etching, a step of attaching an insulating film to one surface of the circuit pattern conductor, a step of cutting off the joint with the insulating film of the portion, And covering the circuit pattern conductor and the insulating film with a coating resin in a state where the portions are exposed.

According to this manufacturing method, a thin resin film is attached to the circuit pattern conductor to which the partial conductors are joined at the joints, and the partial conductors are fixed, and the joints are cut off before the resin coating. Since the work is easy and accurate, and the cut end face is covered with the coating resin, it is not necessary to fill only the cut portion with the resin later, so that the workability is improved and the reliability is improved.

According to a second aspect of the present invention, a conductor foil material is pressed by leaving a joint at an arbitrary position between adjacent partial conductors so that a plurality of partial conductors which are to be independent from each other are not decomposed. Or a step of forming a circuit pattern conductor by etching, a step of temporarily bonding any part between adjacent partial conductors except for the connection part of the circuit pattern conductor with a temporary fixing resin, and a step of bonding the circuit pattern conductor. The method includes a cutting step and a step of covering the circuit pattern conductor and the temporary fixing resin with a coating resin in a state where required portions of the circuit pattern conductor are exposed.

According to this manufacturing method, the partial conductors joined at the joints are fixed with the temporary fixing resin, and the joints are cut off before the resin coating, so that the cutting operation is easy and accurate.
In addition, since the cut end surface is also covered with the coating resin, there is no need to fill the cut portion with resin later, and workability is improved,
In addition, reliability is improved.

When the same kind of resin is used for the temporary fixing resin and the coating resin, the resins are integrally fused to form a uniform resin layer.

[0016]

Embodiments of the present invention will be described below in detail with reference to the drawings. (Embodiment 1) FIGS. 1A to 1D show a method of manufacturing a circuit board according to Embodiment 1 of the present invention.
Is a circuit pattern conductor, 1a, 1b, 1c are partial conductors, 2 is a coupling portion, 3 is a gap between partial conductors, 9 is an insulating film, 10
Denotes a cut portion, 11 denotes a cut piece, 12 denotes a coating resin, and 13 denotes an exposed portion of the circuit pattern conductor 1.

Next, a method of manufacturing the circuit board according to the first embodiment will be described. First, in FIG. 1 (a), the conductor foil material is pressed or etched so as to leave the joining portion 2 so that the plurality of partial conductors 1a, 1b, 1c which are to be finally separated independently do not separate apart. The circuit pattern conductor 1 is formed. A gap 3 is formed between the partial conductors.

Although the material for forming the circuit pattern conductor 1 is a conductor foil material, a plate-shaped material having a thickness greater than that of the foil is also included therein. Also, the partial conductors 1a, 1b, 1
As described in the description of the conventional example, c actually has a more complicated shape.

In FIG. 1B, an insulating film 9 is adhered to one surface of the circuit pattern conductor 1. Various methods such as adhesives and heat bonding can be applied as the bonding method. The type of the insulating film 9 to be used is not particularly limited as long as it can prevent the partial conductors from being separated from each other until the covering resin 12 is covered after the joint portion 2 is cut off. However, when the insulating film 9 is coated with the coating resin 12 to cover the circuit pattern conductor 1, it is better if the insulating film 9 is integrated with the coating resin 12 or is made of a material having good adhesion to the circuit pattern conductor 1. Needless to say. It is also conceivable to make a hole in the insulating film 9 at a position corresponding to the component mounting portion of the circuit pattern conductor 1 in advance.

Next, in FIG. 1 (c), the joint 2 of the circuit pattern conductor 1 is cut off together with the insulating film 9 at that portion by press working or another method. In other words, by cutting off the joint portion 2 which has been stopped so that the partial conductors 1a, 1b, 1c do not separate apart, the partial conductors 1a, 1b, 1c are cut off.
1b and 1c are separated into individual conductors which are electrically independent from each other, and become predetermined circuit conductors.

However, in this state, the partial conductors 1a, 1a
Since the fixing of b and 1c is extremely weak, there is a problem in quality and reliability. Further, as shown in FIG.
Resin 12 covering circuit pattern conductor 1 and insulating film 9
Cover with. That is, the circuit pattern conductor 1 from which the coupling portion 2 is cut off
Then, the insulating film 9 is put into a molding die (not shown), and a resin is injected to mold the resin. In this case, an exposed portion 13 of the circuit pattern conductor 1 is formed in a portion corresponding to the component mounting portion on the circuit pattern conductor 1. In this way, after a series of steps, the circuit board is completed.

As described above, according to the first embodiment,
Since the partial conductors 1a, 1b, and 1c are fixed by bonding the insulating film 9 to the circuit pattern conductor 1 joined by the joint 2, the joint is cut off before the resin coating.
The resection operation is easier and more accurate. Further, since the cut portion 10 is also covered with the coating resin 12, the circuit pattern conductor 1
The excision end of the will no longer remain exposed,
High reliability.

(Embodiment 2) FIGS. 2 (a) to 2 (d) show a method of manufacturing a circuit board according to Embodiment 2 of the present invention. Attached
14 is a temporary fixing resin.

In the manufacturing method according to the second embodiment, first, as shown in FIG.
The circuit pattern conductor 1 is formed by pressing or etching the conductive foil material.

Next, in FIG. 2B, an arbitrary portion between the adjacent partial conductors except for the joint 2 of the circuit pattern conductor 1 is joined with a temporary fixing resin 14. That is, the temporary fixing resin 14 is partially injected into the gap 3 using a molding die or the like, the partial conductors 1a, 1b, 1c are joined, and the partial conductors are not separated when the joint 2 is cut. To Although the temporary fixing resin 14 has a partially independent shape in the figure, it may be connected to each other, and the amount thereof may be arbitrarily set without any particular limitation.

The material of the resin to be used is optimal as long as it can be fused with the coating resin used in the subsequent step. However, if the material is not fused or hardly fused, it is possible to temporarily fix the resin as small as possible. If this is not the case, it can be said that it is better to give priority to cost.

Next, in FIG. 2C, the joint 2 of the circuit pattern conductor 1 is cut off by a method such as press working.
10 is a resected part and 11 is a resected piece. At this point, each of the partial conductors 1a, 1b, 1c is separated into individual electrically independent conductors and becomes a predetermined circuit conductor. However, such a circuit conductor is insufficient in terms of strength, safety, and the like.

Therefore, as shown in FIG. 1 (d), the circuit pattern conductor 1 and the temporary fixing resin 14 are covered with the covering resin 12 in a state where required portions of the circuit pattern conductor 1 are exposed. That is, the circuit pattern conductor 1 from which the coupling portion 2 has been cut is put into a molding die (not shown), and a resin is injected to mold the resin. In this way, after a series of steps, the circuit board is completed.

As described above, according to the second embodiment,
Since the partial conductors 1a, 1b, 1c are fixed with the temporary fixing resin 14 and the joint is cut off before coating with the resin, the cutting operation is easy and accurate, and the cutout 10 is also covered with the coating resin 12,
The cut end face of the circuit pattern conductor 1 does not remain exposed, and the reliability is high.

[0030]

As described above, according to the present invention,
After fixing the partial conductors that make up the circuit pattern in advance with an insulating film or temporary fixing resin, the joint is cut off, and then the whole is covered with the coating resin 12, so the joint is cut off after resin coating as in the past. Compared to the method, the cutting operation of the joint portion is easier and more accurate, and the cut portion is covered with the covering resin, so that there is an effect that a highly reliable circuit board can be manufactured.

[Brief description of the drawings]

FIG. 1 is a manufacturing process diagram of a circuit board according to Embodiment 1 of the present invention.

FIG. 2 is a manufacturing process diagram of a circuit board according to Embodiment 2 of the present invention.

FIG. 3 is a manufacturing process diagram of a circuit board in a conventional example.

[Explanation of symbols]

1 ... circuit pattern conductor, 2 ... joint, 3 ... gap,
9 ... insulating film, 10 ... cut part, 11 ... cut piece, 13
... exposed conductor, 14 ... temporary fixing resin.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hiroyuki Uchiyama 1006 Kazuma Kadoma, Kadoma City, Osaka Matsushita Electric Industrial Co., Ltd.

Claims (2)

[Claims] In order to prevent a plurality of partial conductors which are to be independent from each other from being decomposed, a conductor foil material is pressed or etched by leaving a joint portion at an arbitrary position between adjacent partial conductors to form a circuit pattern conductor. Forming, attaching an insulating film to one surface of the circuit pattern conductor, cutting off the joint portion together with the insulating film at that portion, and exposing a required portion of the circuit pattern conductor. Covering the circuit pattern conductor and the insulating film in a state with a coating resin. 2. A circuit pattern conductor is pressed or etched by pressing or etching a conductor foil material while leaving a connection portion at an arbitrary position between adjacent partial conductors so that a plurality of partial conductors which are to be independent from each other are not decomposed. Forming, and joining any part between the adjacent partial conductors with a temporary fixing resin except for the coupling portion of the circuit pattern conductor,
The method comprises a step of cutting off a joint of the circuit pattern conductor, and a step of covering the circuit pattern conductor and the temporary fixing resin with a coating resin in a state where required portions of the circuit pattern conductor are exposed. A method for manufacturing a circuit board.