JPH1146097A - Resin-molded circuit board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To temporarily fix an electronic component mounted on a resin-molded circuit board which utilizes the characteristics of the board on the board, without using a special member or a special process until the component is soldered to the board. SOLUTION: When resin-molding, wherein the both surfaces of a conductor plate 2 formed with a circuit pattern are covered with a resin layer 3 is performed, lead insertion holes 6 and soldered open parts 8 are formed in positions, which correspond to lead connection holes 4 formed in the plate 2 on the layer 3. A plurality of elastic energizing pieces 10, which turn from the peripheral edge part of each of the holes 6 towards the center of the hole 6, and formed in the hole 6. When leads 7 of an electronic component 5 are inserted in the holes 6, the pieces 10 are extended in the directions of penetration of the leads 7, and the leads 7 are respectively inserted in each hole 6 to a prescribed position in the hole 6. As the inserted leads 7 are held at the prescribed positions through the energization of the pieces 10, the component 5 is fixed temporarily on a resin-molded circuit board.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin-molded circuit board obtained by coating a conductor plate on which a circuit pattern is formed with a resin by resin molding, and is inserted into a lead insertion hole provided in the resin-molded circuit board. The present invention relates to a resin molded circuit board having a structure for holding leads of electronic components and temporarily fixing the leads until they are fixed to a conductive plate by soldering.

[0002]

2. Description of the Related Art In contrast to a general circuit board configuration in which a circuit pattern is formed on a conductor such as a copper foil adhered on an insulating plate, a conductor such as a copper plate processed into a circuit pattern shape is formed by resin molding. BACKGROUND ART A resin-molded circuit board covered with a resin layer has attracted attention as a circuit board structure useful for forming a power supply circuit or the like having a large circuit current because a conductor plate having a large thickness can be used.

[0003] Regardless of the circuit board structure, it is well known that in order to manufacture an electronic circuit board, it is necessary to mount electronic components at predetermined positions on the circuit board and solder the leads of the electronic components to conductors. It is as follows. In the manufacture of an electronic circuit board using an electronic component mounting apparatus, after mounting a plurality of electronic components on a circuit board, the electronic components are transported to a soldering process, and the mounted electronic components are collectively soldered. It is important that the electronic component mounted by the movement in the soldering process is temporarily fixed so as not to be detached from a predetermined position. In order to perform the temporary fixing of the electronic component, in the related art, FIGS. The processing shown in FIG.

The processing for temporary fixing shown in FIG. 4 is performed by bending a lead 32 of an electronic component 33 inserted into a lead insertion hole 31 formed in a circuit board 30 on the conductor 30b side of the circuit board 30. By processing, it is temporarily fixed to prevent the electronic components from falling off or floating.
In the electronic component 33 mounted as described above, the conductor 30b and the lead 32 are connected by welding the solder 35 to a portion where the surface of the conductor 30b is not covered with the mask 34 in the soldering process.

The processing for temporary fixing shown in FIG. 5A is mainly used for mounting relatively large electronic components, for example, electrolytic capacitors and the like. A fixing agent 37 as an adhesive or a sealing agent is applied to the side, and the electronic component 36 in which the lead 32 is inserted into the lead insertion hole 31 is temporarily fixed at a predetermined position by the fixing agent 37. Further, in a soldering step in which soldering means such as dip soldering is used, gas is generated along with the soldering. Thus, in the case of the electronic component 36 which is attached in close contact with the insulating plate 30a, When the lead insertion hole 31 is closed by the electronic component 36, there is no gas escape path,
Poor soldering occurs due to gas accumulation.

Therefore, as shown in FIG. 5B, a ring 38 for forming a gas vent passage at the base of the lead 32 is used.
Are also used for the purpose of temporarily fixing the electronic component 36 at the same time as degassing.

[0007]

The above-mentioned means for temporarily fixing the electronic parts has been described by way of example of a conventional general circuit board, but the same applies to the case where a resin-molded circuit board also needs to be temporarily fixed. In order to temporarily fix the electronic component, as shown in FIG. 4, a clinch mechanism is required in the electronic component mounting device to bend the lead in the mounting process, and one process is required for the bending. Become. Also, the temporary fixing means using an adhesive or a ring requires necessary materials, devices, and steps for implementing this.

[0008] Such a temporary fixing procedure is an element that leads to an increase in manufacturing cost and a decrease in productivity. If the elements necessary for temporary fixing can be eliminated, the increase in the manufacturing cost and production Can be suppressed.

The inventors of the present invention have paid attention to this and have devised a structure for temporarily fixing an electronic component by utilizing a configuration peculiar to a resin molded circuit board. It is an object of the present invention to provide a resin molded circuit board in which a temporary fixing structure for electronic components is simultaneously formed.

[0010]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a lead insertion hole for an electronic component and a solder at a position corresponding to a lead connection hole of the electronic component provided on a conductor plate on which a circuit pattern is formed. Mounting holes are provided to cover and bond the conductor plate with a resin layer formed by resin molding. A position where the lead of the electronic component is inserted from the lead insertion hole, passes through the lead connection hole, and faces the lead insertion hole. In a resin molded circuit board configured to mount an electronic component by penetrating the soldering opening formed in the resin insertion resin, the resin holding the lead of the inserted electronic component in the lead insertion hole by elastic biasing The molded piece is formed so as to extend integrally from the resin layer.

[0011] According to the above configuration, the lead of the electronic component inserted into the lead insertion hole is elastically urged by the resin molded piece formed in the lead insertion hole and held in position, so that the mounted electronic component is not mounted. It is temporarily fixed at a predetermined position. This temporary fixing is automatically performed by performing a conventional mounting process of inserting a lead into a lead insertion hole in order to mount an electronic component, and a clinch structural element for bending the lead and its process, Alternatively, temporary fixing by bonding or the like is unnecessary.

Further, in the above-mentioned structure, a gas vent groove is formed in a peripheral portion of a lead insertion hole through a lead connection hole provided in a conductor plate to a surface of a resin coating, so that an electronic component to be mounted is in close contact with a substrate. Even if you wear it,
Degassing is performed without using a special member for degassing, thereby preventing the occurrence of defective soldering.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings to provide an understanding of the present invention.
The resin-molded circuit board is different from a generally used circuit board in which a circuit pattern is formed by etching a conductive layer such as a copper foil adhered on an insulator substrate, and is 0.1 to 2 m.
A conductor plate such as a copper plate having a thickness of m is formed into a circuit pattern shape by a method such as press working or etching work, and an electrically insulating resin layer is coated and bonded to the circuit board by resin molding. When a circuit pattern is formed on the conductor plate,
The conductor plate will be divided into a plurality of parts and will be separated.However, connecting parts connecting the divided parts are arranged at key points to prevent separation, and after the resin molding, the connecting parts are punched by a punching press or the like. To complete the circuit pattern.

Further, at the time of resin molding, a molding die is designed so that a lead insertion hole and a soldering opening for soldering an electronic component formed on a conductor plate are formed.

FIG. 1 (a) shows an electronic component 5 which is a lead component such as a resistor on a resin molded circuit board 1 according to the present embodiment.
FIG. 6 is a cross-sectional view showing a state where the is mounted and soldered. The resin-molded circuit board 1 has a resin layer 3 on both sides of a conductor plate 2 on which a circuit pattern is formed by resin molding and a resin layer 3 and a resin layer on both sides of a portion where the conductor plate 2 is separated by the formation of a circuit pattern. 3 fills and fuses the separated portion to enhance the insulation of the separated portion and at the same time, the resin layers 3 on both surfaces
Are integrated to improve the strength of the substrate. When the resin layer 3 is formed on the conductive plate 2, the lead 7 of the electronic component 5 is inserted into one surface of the resin layer 3 at a position corresponding to the lead connection hole 4 formed on the conductive plate 2. A lead insertion hole 6 and a soldering opening 8 for soldering the lead 7 to the conductor plate 2 are formed on the other surface. In resin molding, in addition to this, fixing holes for large components, fixing holes for the circuit board itself, and the like are simultaneously formed.

As shown in the plan view of FIG. 1B, the lead insertion hole 6 has a plurality of elastic biasing pieces (resin molded pieces) 10 tapered from the peripheral edge of the hole toward the center.
Are formed integrally with the resin layer 3. This elastic biasing piece 1
In the case of No. 0, as shown in the cross section of FIG. 1A, an inclined surface is formed from the peripheral portion toward the center, and the tip portion is formed so that the resin molding thickness becomes thin. In addition, a plurality of elastic biasing pieces 1
The space diameter of the center part surrounded by the 0
Is formed so as to be slightly smaller than the diameter of the lead 7 of the electronic component 5 to be inserted. Accordingly, when the lead 7 is inserted into the center of the lead insertion hole 6 formed in such a form, the lead 7 enters the elastic urging piece 10 in such a manner as to push the distal end of the elastic urging piece 10 in the entering direction. When inserted to the predetermined mounting position shown in FIG. 1 (a), each elastic biasing piece 10 expanded by the lead 7 presses the lead 7 from the surroundings by elastic bias. And the electronic component 5 is mounted on the resin molded circuit board 1
Will be temporarily fixed. Further, since the elastic biasing piece 10 of the lead insertion hole 6 forms an inclined surface from the peripheral edge toward the center, there is a slight error in the spacing between the leads 7 of the electronic component 5. Is also guided to the center by the inclined surface and inserted into the center of the lead connection hole.

The shape of the elastic biasing piece 10 formed in the lead insertion hole 6 as described above may be configured as shown in FIG. 2 as a modified example of (a), (b), and (c). FIG.
The configuration of the lead insertion hole 6a shown in FIG.
Since the number of Oa is increased, it is ensured that the lead 7 is guided to the center part, so that the present invention can be applied to a case where there is a large error in the insertion interval between the leads 7,7. In the lead insertion hole 6b shown in FIG. 2B, a rib-like elastic biasing piece 10b is formed along one diameter line of the lead insertion hole 6b. In the example shown in the figure, the elastic biasing piece 10b is formed in a wave shape and bridges the opposing portion of the lead insertion hole 6b.
Can be formed in a shape such as a straight line. Then, the electronic component 5 is temporarily fixed by urging the lead 7 from the lead insertion hole 6b toward the lead connection hole 4 from the side by the elastic urging piece 10b. Further, in the lead insertion hole 6c shown in FIG. 2C, a rib-shaped elastic urging piece 10c bridging the lead insertion hole 6c is formed so that its cross-sectional shape becomes triangular. As shown in d), the inserted lead 7 is guided by a triangular inclined surface so as to be sandwiched between the peripheral edge of the lead insertion hole 6c and the elastic biasing piece 10c. The lead 7 is held by the elastic pressure, and the electronic component 5 is temporarily fixed.

After a plurality of electronic components are mounted and temporarily fixed on the resin-molded circuit board 1 according to the above configuration, the resin-molded circuit board 1 is transferred to a soldering step to remove the leads 7 of the temporarily fixed electronic components 5. The step of soldering to the conductor plate 2 is performed. As shown in FIG. 1C, the resin molded circuit board 1
A soldering opening 8 is formed on the other surface side of the substrate, and the conductor plate 2 is exposed in the soldering opening 8, so that a soldering process such as dip soldering is performed to obtain a soldering opening 8 shown in FIG. As shown in (1), the lead 7 and the conductor plate 2 are joined by solder 9.

In the soldering process, the electronic component 5
Is mounted in close contact with the surface of the resin molded circuit board 1 such as an electrolytic capacitor or the like, the electronic component 5 blocks a passage of gas generated from flux, moisture, or the like at the time of soldering. Therefore, if an appropriate degassing process is not performed, poor soldering occurs due to accumulation of gas in the soldering opening 8. In order to cope with the degassing in the prior art, as shown in FIG. 5B, it was necessary to provide a member such as a ring 38 that forms a degassing passage. According to the characteristics of the circuit board 1, the gas vent structure can be formed without providing a special member.

FIG. 3 shows an electronic component 1 having a gas release structure.
1 shows a mounting structure of the electronic component 11, which is mounted in close contact with the surface of the resin molded circuit board 1.
As shown in FIG. 3B, one gas vent groove 14 is provided on the lead insertion hole 6 side, and as shown in FIG. It is formed by molding. If there is no gas vent groove 14, the lead insertion hole 6
Although the upper portion is covered with the electronic component 11, there is no escape of gas that tends to escape upward from the lead connection hole 4, but a gas escape groove 14 forms a passage that escapes from the lead connection hole 4 to the substrate surface. The gas vent groove 1 is also provided in the soldering opening 8.
By forming the holes 3, it becomes difficult for gas to accumulate in the soldering opening 8, and it is possible to reduce gas leaking in the direction of the lead connection hole 4.

[0021]

As described above, according to the present invention, the lead of the electronic component inserted into the lead insertion hole is elastically urged by the resin molded piece formed in the lead insertion hole to be held in position. The mounted electronic component is temporarily fixed at a predetermined position. This temporary fixing is automatically performed temporarily by performing a conventional mounting process of inserting a lead into a lead insertion hole in order to mount an electronic component,
There is no need for a clinch structural element for bending the lead, its process, or temporary fixing by bonding or the like.

Further, in the above-mentioned structure, the electronic component to be mounted is in close contact with the substrate by forming a gas vent groove at the peripheral edge of the lead insertion hole from the lead connection hole provided in the conductor plate to the surface of the resin coating. Even if you wear it,
Degassing can be performed without using a special member for degassing, thereby preventing the occurrence of defective soldering.

[Brief description of the drawings]

1A and 1B show an electronic component mounting structure according to an embodiment of the present invention, wherein FIG. 1A is a cross-sectional view, FIG. 1B is a plan view of a lead insertion hole, and FIG. 1C is a plan view of a soldering opening. .

FIGS. 2A, 2B, and 2C are plan views showing modifications of a lead insertion hole, respectively, and FIG. 2D is a cross-sectional view of FIG.

3A and 3B show an electronic component mounting structure provided with a gas vent groove, in which FIG. 3A is a cross-sectional view, FIG. 3B is a plan view of a lead insertion hole, and FIG. 3C is a plan view of a soldering opening.

FIG. 4 is a cross-sectional view showing an electronic component mounting structure according to the related art.

FIGS. 5A and 5B are cross-sectional views showing a conventional electronic component mounting structure, in which FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Resin molded circuit board 2 Conductor plate 3 Resin layer 4 Lead connection hole 5 Electronic component 6 Lead insertion hole 7 Lead 8 Soldering opening 10 Elastic biasing piece (resin molded piece)

Claims (2)

[Claims] An electronic component lead insertion hole and a soldering opening are provided at positions corresponding to lead connection holes of an electronic component provided on a conductor plate on which a circuit pattern is formed. It is coated and connected, and the lead of the electronic component is inserted from the lead insertion hole, passed through the lead connection hole, and penetrated through the soldering opening formed at a position facing the lead insertion hole, and the electronic component is inserted. In the resin-molded circuit board configured to be mounted, a resin-molded piece for holding a lead of an inserted electronic component by elastic biasing is integrally extended from the resin layer in the lead insertion hole. Resin molded circuit board. 2. The resin-molded circuit board according to claim 1, wherein a gas vent groove is formed in a peripheral portion of the lead insertion hole so as to escape from a lead connection hole provided in the conductor plate to a surface of the resin coating.