JPH11186700A - Circuit board and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a circuit board manufacturing method which can manufacture a circuit board equipped with an electric circuit containing a coil, in stable quality at low cost. SOLUTION: A comb-shaped part where a plurality of branches 5 are extended from a trunk 6 is molded in a conductor 2, an iron core 10 is placed in roughly parallel with the trunk 6 on the branches 5, and the branches 5 are molded to roll in the iron core 10. Each tip is joined with the root of the adjacent branch 5, and then the trunk 6 is cut down. As a result, a coil 11 is made on the board 1, and the lead wire winding process in manufacture of the coil 11 is replaced with the process of die cutting of the conductor 2 in the board 1, the process of forming, and the process of joining.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a switching power supply used for a rice cooker and an air conditioner, an inverter circuit, and the like.
The present invention relates to a circuit board forming method including an electric circuit including a coil used for an audio circuit and the like, and a circuit board.

[0002]

2. Description of the Related Art Conventionally, when manufacturing a circuit board provided with an electric circuit including a coil, a separately manufactured coil is mounted on a surface of a substrate having a wiring pattern formed of conductors on the back surface. The two ends of the conductor wire are inserted into a pair of mounting through holes provided on the board, and soldered to the wiring patterns and mounting terminals on the back side of the board to secure the coil and achieve electrical continuity, forming a circuit board Was. Further, the coil is formed by spirally winding a thin conductive wire around the annular core along the circumference thereof.

FIGS. 11 and 12 show a conventional circuit board having a smoothing circuit as an example of a circuit board having an electric circuit including a coil. 11 and 12, reference numeral 21 denotes a circuit board on which one coil 22 and two capacitors 23 are mounted. The coil 22 is formed by spirally winding a conducting wire 25 around an annular core 24, and both ends of the conducting wire 25 penetrate the substrate 21 and are soldered to a conductor pattern 26 on the back surface.
Are joined together.

A lead 28 of the capacitor 23 also penetrates the substrate 21 and is joined to a conductor pattern 26 on the back surface by solder 27.

[0005]

However, in the manufacturing process of the coil 22, the annular core 24 serving as a core is used.
The step of spirally winding the conductive wire 25 is performed by using a winding machine, and depending on the case, depending on the manual operation, time is required for manufacturing the coil 22 and the number of turns of the conductive wire 25 wound around the annular core 24 is required. As the number increases, processing time is required, and there is a problem that productivity is low.

[0006] The low productivity affects the cost, and the processing cost of the coil is higher than other electronic parts. Therefore, in the case of a circuit board using a coil,
There is a problem that component costs are higher than a circuit board that does not use a coil, and it is difficult to reduce the cost of the circuit board itself.

In addition, when a manual operation is interposed in the manufacturing process, there is a possibility that a required characteristic value is not realized or a quality problem such as a shape distortion occurs.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and has as its object to provide a circuit board forming method and a circuit board capable of manufacturing a circuit board having an electric circuit including a coil at low cost and with stable quality. I have.

[0009]

According to the present invention, there is provided a circuit board forming method for forming an electric circuit including a coil on a substrate formed of a conductor and a resin covering the conductor, wherein a plurality of branches extend from a trunk to the conductor. Formed comb-shaped part, put the iron core on the branch part almost parallel to the trunk, shape the branch part so as to wind the core, join the tip to the root of the adjacent branch part, and then The coil is formed on the substrate by cutting off the trunk, and the winding process of the conductor wire in the manufacture of the coil can be replaced by the punching, forming, and joining processes of the conductor, and the time can be greatly reduced. The cost can be reduced, and the quality can be stabilized by automation.

[0010] Further, by using an integral iron core, the electrical characteristics and quality of the coil can be stabilized.

Further, when joining the tip of the branch portion and the root portion together with other mounted components, one step of coil manufacturing can be reduced, and the cost can be further reduced.

Further, a pair of rectangular portions are formed in parallel on the conductor, and cuts are alternately formed in the rectangular portions from both sides thereof, and the pieces formed by the cuts are alternately moved up and down to form a gap between the upper and lower pieces. When a coil is formed on a board by forming a space in the space and inserting an iron core into the space from the direction perpendicular to the notch, it is necessary to join using multiple iron cores, and an integral iron core can not be used, but conductors Can be reduced, and the reliability can be improved.

A circuit board according to the present invention is a circuit board in which an electric circuit including a coil is formed on a board made of a conductor and a resin covering the conductor, and the conductor is provided around an iron core disposed on the conductor. It is provided with a coil formed by winding the spiral conductor portion formed in the above.Since the spiral conductor portion of the coil is constituted by the conductor of the substrate, there is no need to separately manufacture a coil, and the coil is The cost of a circuit board including the same can be reduced.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a circuit board forming method according to the present invention will be described in which one surface of a conductor is covered with a resin.
One embodiment applied to the manufacture of a circuit board formed by forming a smoothing circuit composed of one coil and two capacitors will be described with reference to FIGS.

First, in the manufacturing process of the substrate 1, FIG.
As shown in FIG. 4, the substrate 1 is formed by covering both surfaces of the conductor 2 with the resin 3. However, the required area of the surface and the back surface of the mounting location of the coil or the capacitor is formed so that the resin 3 is not formed. I have. Next, as shown in FIG. 1, the conductor 2 exposed on the surface side at the coil mounting portion is formed with a large number of branch portions 5 serving as conductor portions for winding the iron core 10 from the trunk portion 6 with a punch, a mold or the like. Punching is performed on the pair of extended comb-shaped portions 4, 4. These comb-shaped portions 4 are formed such that the branches 5 of the other comb-shaped portion 4 enter between the branches 5 of the one comb-shaped portion 4 and are slightly inclined. Further, the tip 5a of the branch 5 is processed to be thin, and an insertion hole 7 is formed in the root 5b of the branch 5 so that the tip 5a can be inserted in a later step.

Next, as shown in FIG.
An iron core 10 is placed in the middle of the trunks 6 and 6 of 4 in parallel with them, and the branch 5 is processed so as to spirally wrap the iron core 10.

At this time, each branch 5 is formed so as to wind around the iron core 10 and the tip 5a is connected to the root 5b of another adjacent branch 5.
Into the insertion hole 7.

Then, as shown in FIGS. 3 and 4, an unnecessary portion of the trunk portion 6 of the comb-shaped portions 4, 4 is punched by a punch, a mold or the like, and the coil winding 9 formed by the branch portion 5 is made of an iron core. 1
Then, the coil 11 is finished in a state where 0 is spirally wound.

Next, as shown in FIGS. 5 and 6, two capacitors 12 are mounted by inserting their leads 13 into capacitor insertion holes 8 formed at predetermined positions on the substrate 1. However, the mounting procedure of other components such as the coil 11 and the capacitor 12 is not particularly limited. Finally, the joining of the tip 5a of the branch 5 and the root 5b and the joining of the lead 13 of the capacitor 12 and the conductor 2 with the solder 14 are performed simultaneously. In this way, a circuit board having a smoothing circuit composed of one coil 11 and two capacitors 12 is manufactured.

Next, another embodiment of the circuit board forming method of the present invention will be described with reference to FIGS. Note that the same components as those in the above embodiment are denoted by the same reference numerals, description thereof will be omitted, and only different points will be described.

In this embodiment, the conductor 2 at the coil mounting location is
Next, as shown in FIG. 7, a pair of rectangular portions 15 are formed in parallel, and cuts 16 are made in these rectangular portions 15 alternately from both sides thereof. Next, as shown in FIGS. 8 and 10, the conductor 2 has a space 18 corresponding to the cross-sectional shape of the iron core 10 by bending a piece 17 formed by the cut 16 and moving the same alternately up and down. Form into a spiral. Although this step is separated from the previous step for the purpose of explanation, the step of forming the cut 16 in the conductor 2 and the step of bending and spirally forming the conductor 2 can be performed simultaneously with a mold or the like. Finally, as shown in FIGS. 9 and 10, the core 10 a divided into a pair or more is inserted into the space 18 from a direction perpendicular to the cut 16 and joined by soldering or welding. Constitute. The coil 11 is formed on the substrate 1 by the above steps.

[0022]

According to the circuit board forming method of the present invention, as is apparent from the above description, a comb-shaped portion having a plurality of branches extending from a trunk portion is formed on a conductor, and an iron core is placed on the branches. A coil is formed on a substrate by placing the branch approximately parallel to the trunk, forming the branch so as to wind the core, joining the tip to the root of the adjacent branch, and then cutting off the trunk. , The winding process of the conductor in the manufacture of the coil,
It can be replaced by the steps of punching, forming, and joining conductors, so that time can be greatly reduced, cost can be reduced, and quality can be stabilized by automation.

Further, by using an integral core, the electrical characteristics and quality of the coil can be stabilized.

Further, when the tip of the branch portion and the root portion are joined together with other mounted components, one step of coil production can be reduced, and the cost can be further reduced.

Also, a pair of rectangular portions are formed on the conductor in parallel, and cuts are made alternately from both sides of these rectangular portions, and the pieces formed by the cuts are alternately moved up and down to form a gap between the upper and lower pieces. When a coil is formed on a substrate by forming a space in the space and inserting an iron core into the space in a direction perpendicular to the notch, the number of joints between conductors can be reduced, and reliability can be improved.

In addition, the circuit board of the present invention is a circuit board in which an electric circuit including a coil is formed on a board composed of a conductor and a resin covering the conductor. Since a coil formed by winding the formed spiral conductor is provided, the coil conductor is constituted by the conductor of the substrate, so that there is no need to separately manufacture a coil, and the circuit board including the coil is not required. Cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a plan view showing a state in which a conductor of a substrate has a comb shape in an embodiment of a circuit board forming method of the present invention.

FIG. 2 is a plan view showing a state in which an iron core is arranged on a substrate and processed so as to be wrapped by a conductor in the embodiment.

FIG. 3 is a plan view showing a state in which unnecessary conductors are cut and removed in the embodiment.

FIG. 4 is a sectional view taken along the line AA of FIG. 3;

FIG. 5 is a plan view showing a state where a smoothing circuit is formed in the embodiment.

FIG. 6 is a sectional view taken along the line BB of FIG. 5;

FIG. 7 is a plan view showing a state in which a conductor of a substrate is punched into a predetermined shape in another embodiment of the circuit board forming method of the present invention.

FIG. 8 is a plan view of the same embodiment in a state where a conductor is formed into a predetermined shape.

FIG. 9 is a plan view showing a state where a coil is formed by inserting and joining an iron core in the embodiment.

FIG. 10 is a sectional view taken along the line CC of FIG. 9;

FIG. 11 is a plan view of a circuit board having a smoothing circuit in a conventional example.

FIG. 12 is a sectional view taken along the line DD in FIG. 11;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 2 Conductor 3 Resin 4 Comb part 5 Branch part 5a Tip 5b Root part 6 Trunk part 10 Iron core 11 Coil 15 Rectangular part 16 Notch 17 Piece 18 Space

Continued on the front page (72) Inventor Yuichi Nakajima 1006 Kazuma Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (5)

[Claims] 1. A circuit board forming method for forming an electric circuit including a coil on a substrate composed of a conductor and a resin covering the conductor, wherein a comb-shaped portion having a plurality of branches extending from a trunk portion is formed on the conductor. Then, the core is placed on the branch almost parallel to the trunk, the branch is formed so as to involve the core, the tip is joined to the root of the adjacent branch, and then the trunk is cut off to mount the coil on the substrate. A method for forming a circuit board, comprising: forming a circuit board on the circuit board; 2. The circuit board forming method according to claim 1, wherein the iron core is integrated. 3. The joint between the tip of the branch and the root is simultaneously joined with another mounted component.
The method for forming a circuit board according to the above. 4. A substrate forming method for forming an electric circuit including a coil on a substrate constituted by a conductor and a resin covering the conductor, wherein a pair of rectangular portions are formed in parallel on the conductor,
In addition, cuts are made alternately from both sides of these rectangular parts, and the pieces formed by the cuts are alternately moved up and down to form a space between the upper and lower pieces, and an iron core is inserted into the space from a direction perpendicular to the cut. Forming a coil on a substrate by using the method described above. 5. A circuit board in which an electric circuit including a coil is formed on a board composed of a conductor and a resin covering the conductor, and a spiral formed by the conductor around an iron core disposed on the conductor. A circuit board comprising: a coil formed by winding a conductor.