JPS6163081A - Electronic circuit part and its mounting method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to electronic circuit components used in a wide range of electronic devices such as television receivers and magnetic recording/reproducing devices, and a method for mounting the same.

Conventional configurations and their problems In recent years, as the demand for smaller and lighter electronic devices has increased, mounting technology to increase the density of these electronic device circuits has become an extremely important technical issue. There is.

Under these circumstances, various attempts have been made to increase the density of electronic circuits in recent years, and in particular, many electronic devices are using methods to increase the density of circuits by creating functional blocks. 0 This mounting method divides a circuit into small functional blocks, gathers the circuit elements that make up these functional blocks on a circuit board at high density, and creates a circuit block9. An electronic circuit is constructed by mounting the circuit on a mother printed wiring board together with circuit elements of the circuit.

This circuit block body is also called a module component or a hybrid integrated circuit component, but here, this circuit block body will be referred to as an electronic circuit component.

By the way, various shapes and structures are currently used for such electronic circuit components, and they play a major role in increasing the density of electronic circuits. In the past, an application was filed for the method shown in Figure 1 as a mounting method for electronic circuit boards (Japanese patent application filed in 1983).
-174919). This consists of a circuit conductor layer 2 made of copper foil on the main surface of a flexible insulating substrate 1, and a conductor layer 3a serving as external connection terminals along a pair of opposing end surfaces.
, 3b is formed on a part of the back side of the flexible wiring board.
- As a small circuit element 5 necessary for configuring a functional block circuit on a printed wiring board having a special shape formed by gluing a hard support substrate 4 so that the lexiple wiring board can be bent into a U-shaped cross section. It is equipped with planar connection type circuit elements such as chip resistors, chip capacitors, mini-molded ICs, transistors, etc., and the connection terminals are connected to the circuit conductor layer 2 of the flexible wiring board using solder 6.
Two elongated slit holes 9 are formed in the mother printed wiring board 7 by bending an electronic circuit component electrically connected to the mother printed circuit board 7 into a U-shape and providing external connection terminals 3a and 3b facing each other.
a, 9b respectively, and connect the circuit conductor layer 8 of the mother printed wiring board to the external connection terminals 3a, 3 by solder dipping method.
This was a mounting method in which a large-scale electronic circuit board was constructed by connecting the parts 1 and 1 with solder 1o.

However, in electronic circuit components having such a structure, the external connection terminals are formed on a flexible wiring board with a fixed pitch, and are not independent terminals like lead wires, so mother printing is difficult. To mount it on a wiring board, the external connection terminals must be inserted all at once using elongated slit holes, which reduces the degree of freedom in circuit design due to the provision of slit holes on the mother printed wiring board, and reduces the flexibility of mother printed wiring. Problems such as reduced mechanical strength of the board, weak solder joint strength between external connection terminals and mother printed wiring, and
When an electronic circuit component is bent into a U-shape, the radius of a part of the corner must be made as large as possible, otherwise the circuit conductor layer at the bent part may not be able to follow the elongation of the flexible insulating board, resulting in disconnection or other problems. OBJECTS OF THE INVENTION The purpose of the present invention is to solve the above-mentioned drawbacks of the conventional example, to improve solderability without reducing the degree of freedom in circuit design of the mother printed wiring board. It is an object of the present invention to provide an electronic circuit component that has good stability, prevents a decrease in its mechanical strength, further improves the bending durability of the bent portion, and allows high-density mounting, and a method for mounting the same.

Structure of the Invention The electronic circuit component according to the present invention has a circuit conductor layer made of metal foil on at least one main surface of an insulating substrate, and the bent portion is made of only metal foil so that the cross section is bent into a U-shape. It has a shape in which the conductor layer is independently drawn out in the shape of a beam lead. A small circuit element is mounted on a printed wiring board and electrically connected to it.It is bent so that the cross section is U-shaped, and the facing external connection terminals are attached to the mother printed wiring board independently. By inserting it into the through hole and soldering it, an electronic circuit board with high density and excellent reliability can be realized.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 2 is a sectional view of an electronic circuit component according to an embodiment of the present invention, and FIG. 3 is a perspective view thereof.

In FIGS. 2 and 3, 11 is an insulating substrate, 12 is a circuit conductor layer, 13a and 13b are external connection terminals, 14 is a small circuit element, and 16 is a solder.

The method for configuring the electronic circuit component of this embodiment configured as described above will be explained in detail below.

In the electronic circuit component according to this embodiment, as shown in FIG. Conductor layer 13a serving as a terminal.

13b in a beam shape along a pair of opposing end surfaces of the insulating substrate 11, and partially pull out the insulating substrate so that the circuit conductor layer 12 made of metal foil can be freely bent into a U-shape at the center. A printed wiring board with no intervening structure is used, circuit elements 14 necessary for configuring a functional block circuit are mounted on the wiring circuit conductor surface of this printed wiring board, and these circuit elements 14 are connected to circuit conductors by solder 16. It has a structure in which it is electrically connected to the layer 12, and its construction method will be explained in more detail as follows.

That is, in this embodiment, the insulating substrate 11 has a thickness of 0.
．． 1 to Q, a 3 m/m glass epoxy board is used, slit holes are drilled through the glass epoxy board at necessary locations in advance, and metal foil such as copper foil is bonded to the entire surface of this insulating board 11. Thereafter, unnecessary portions of the metal foil were dissolved and removed by photoetching or the like to create a printed wiring board on which the desired circuit conductor layer 12 and external connection terminals 13a and 13b were formed.

In this case, the conductor layer 13a serves as an external connection terminal.

The circuit conductor layer 13b is formed so as to be drawn out in the shape of a beam lead on the upper surface of the elongated through slit hole provided at the opposing ends of the insulating substrate 11, while the circuit conductor layer 12 is formed in the center of the circuit conductor layer. This printed wiring board has a special shape, with two parallel slit-like holes provided so that it can be freely bent into a letter shape, and a circuit conductor layer 12 formed on the top surface.

Next, using the printed wiring board made in this way, chip resistors, chip capacitors, etc.
Furthermore, thin molded transistors, diodes,
A desired functional circuit can be created by mounting various planar connection type circuit elements such as ICs and LSIs and connecting their external connection terminals to the wiring circuit conductor layer 12 with solder 14 using the solder dipping method or solder reflow method. We made electronic circuit components that become blocks.

Then, as shown in FIG. 3, the central part of this electronic circuit component is bent so that the cross section is U-shaped, and the opposing external connection terminals 13a and 13b are connected to the mother printed wiring board 13 as shown in FIG. Independent through holes 18a, 18 provided in
The circuit conductor layer 17 and solder 19 are inserted into the circuit conductor layer 17 and soldered to connect the mother printed wiring board.
were connected to form an electronic circuit board.

Although the electronic circuit components manufactured as described above fully satisfy the basic characteristics and reliability, we aimed to achieve even higher performance, higher reliability, and higher density. Various improvements have been made, and examples thereof will be described below.

One of them is the external connection terminal 13 of the electronic circuit component mentioned above.
By configuring only a and 13b to be partially thicker than the circuit conductor layer 12, the installation to the mother printed wiring board is made easier.More specifically, the thickness of the circuit conductor layer External connection terminals 13a, 1 for 35μ
3b was configured to have a thickness of about 260μ.

Alternatively, as shown in FIG. 5, when an electronic circuit component is bent into a U-shape, a flexible insulating film 2o is partially formed on the wiring circuit conductor layer 12 at the bent portion, and the wiring circuit conductor layer 12 at the bent portion is Improved bending resistance.

Furthermore, with the aim of stabilizing the characteristics of the electronic circuit component according to the present invention, a metal foil 21 is bonded to the surface of the insulating substrate 11 on which the wiring circuit conductor layer 12 is not formed, as shown in FIG. In addition to the shielding effect of the circuit block, we devised a way to provide a heat dissipation effect.

Next, a description will be given of an example of an electronic circuit component according to the present invention, which was studied with the aim of increasing the density of the electronic circuit component.

FIG. 7 shows a planar connection type circuit element in which a circuit element 22 having a lead wire is inserted using a through hole 23 and mounted on a wiring circuit conductor surface 12 from an example in which a wiring circuit conductor layer is not formed on an insulating substrate 11. In this embodiment, an Ayual fin type IC package is used as the leaded circuit element 22 to achieve higher circuit density.

Further, FIG. 8 shows a so-called double-sided through-hole wiring board constructed by forming a desired wiring circuit conductor layer 12 on both the front and back surfaces of an insulating substrate 11 and making a hole 24 that passes through both conductive. It is an electronic circuit component constructed by connecting various planar connection type circuit elements 14 to the surface of each wiring circuit conductor layer, and by bending this electronic circuit component into a U-shape and mounting it on a mother printed wiring board. , it was possible to realize a high-density electronic circuit component with a multilayer component arrangement of substantially four layers.0 Effects of the Invention As is clear from the above explanation, the electronic circuit component according to the present invention has a relatively thin insulating substrate on at least one main surface. The circuit conductor layer has a circuit conductor layer made of metal foil, and the circuit conductor layer has a structure in which the cross section is bent in a U-shape at the center, so that there is no intervening insulating substrate, and the circuit conductor layer is continuous with the circuit conductor layer. It is made by mounting the circuit elements necessary to construct a functional circuit block on a printed wiring board with a special shape in which external connection terminals made of metal foil are drawn out in the shape of beam leads. An electronic circuit board is constructed by bending an electronic circuit component into a U-shape, inserting its external connection terminal into a through hole provided in a mother printed wiring board, and soldering the component.

As described above, since the external connection terminal of the electronic circuit component according to the present invention is integrated with the circuit conductor layer and has an independent lead shape, when it is mounted on the mother printed wiring board, it does not require the use of elongated slit holes as in the conventional example. There is no need to solder using a mother printed wiring board, which increases the degree of freedom in circuit design of the mother printed wiring board, and reduces the reduction in mechanical strength of the mother printed wiring board itself due to the provision of slit holes. Improved solderability between the external connection terminals of electronic circuit components and the circuit conductor layer of the mother printed wiring board,
On the other hand, the reliability of the electronic circuit component according to the present invention, that is, the bending durability of the bent portion when bent into a U-shape is improved. At the same time, even if the corner angle of the bending part is reduced, sufficient bending strength is ensured, which improves the mounting density of electronic circuit components, and dramatically increases the mounting density of mother printed wiring boards on which this is mounted. Effects such as improved performance were obtained.

[Brief explanation of the drawing]

FIG. 3 is a perspective view of an electronic circuit component according to an embodiment of the present invention, FIG. 4 is a sectional view of an electronic circuit component mounted on a mother printed wiring board according to an embodiment of the present invention, and FIGS. 8 are sectional views of electronic circuit components in other embodiments of the present invention. 11...Insulating substrate, 12...Circuit conductor layer, 13a. 13b...External connection terminal, 14...Small circuit element, 15.19...Solder, 16...
...Mother printed wiring board, 17...Mother printed wiring board circuit conductor, 18a, 18b...Mother printed wiring board through hole, 20...Flexible insulation Coating, 21...Metal foil, 22...Circuit element with lead wire, 23...Through hole, 24...
...A through hole that has become conductive. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 3
Figure 4 Figure 5

Claims (7)

[Claims] (1) A circuit conductor layer made of metal foil is provided on at least one main surface of an insulating substrate, the cross section is bent into a U-shape, and the bent portion is made of a circuit conductor layer made only of metal foil. At the same time, a small circuit element is mounted on a printed wiring board having a shape in which external connection terminals made of metal foil continuous with the circuit conductor layer are independently drawn out in the shape of beam leads along a pair of opposing end surfaces, An electronic circuit component characterized by being electrically connected. (2) The electronic circuit component according to claim 1, wherein the conductor layer serving as the external connection terminal is partially thick. (3) The electronic circuit component according to claim 1, wherein a circuit element having a lead wire plate is attached from inside the flat upper surface of the printed wiring board. (4) The electronic circuit component according to claim 1, wherein a metal foil is adhered to the main surface of the insulating substrate on which the wiring circuit conductor layer is not formed. (5) forming wiring circuit conductor layers on both the front and back surfaces of the insulating substrate;
2. The electronic circuit component according to claim 1, wherein both wiring circuit conductors are connected through a through hole, and a circuit element is attached to each wiring circuit surface. (6) The electronic circuit component according to claim 1, characterized in that an insulating coating layer is provided only on the bent portion of the circuit conductor layer. (7) The insulating substrate has a circuit conductor layer made of metal foil on at least one main surface, and the bent portion is made of only metal foil so that the cross section is bent into a U-shape. A small circuit element is mounted on a printed wiring having a shape in which external connection terminals made of metal foil continuous with the circuit conductor layer are independently drawn out in the shape of a beam lead along a pair of opposing end faces, and electrical Bend an electronic circuit component that has a structure connected to the central part so that the cross section is U-shaped, insert the opposing external connection terminals into an independent through hole provided in the mother printed wiring board, and insert the A method for mounting an electronic circuit component, characterized in that the electronic circuit component is connected by solder to a circuit conductor layer provided on the part.