JPH037969Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to a double-sided wiring board formed by electrically connecting copper foil circuits on both sides.

[Conventional technology]

Conventionally, a double-sided wiring board in which copper foil circuits on both sides are electrically connected has been constructed as shown in FIGS. Copper foil circuits 4 are formed on the upper and lower surfaces of the substrate 1, and the copper foil circuits 2 and 3 are formed on the inner surface of a through hole 5 formed in a portion of the substrate 1 containing the copper foil circuits 2 and 3 by through-hole plating technology. The copper foil 6 is solder, and the through hole 5 is soldered by a method called dip soldering.
The copper foil circuits 2 and 3 are electrically connected together with the copper foil 4 from the bottom side.

In addition, conventionally, there is a device as shown in FIG. 7, in which an eyelet 8 is inserted into a hole 7 made transparent in a portion of the board 1 including both copper foil circuits 2 and 3, and the eyelet 8 is attached to the lower surface. It is formed by filling the solder 9 with solder.

Furthermore, Japanese Patent Application Laid-open No. 59-31092 discloses that copper foil circuits that are to be connected to each other are provided on the front and back sides of an insulating substrate so as not to overlap, and that a portion containing only one of the copper foil circuits is penetrated. A hole is provided, an eyelet is inserted and fixed in the through hole, and a conductor or component is provided to electrically connect the other of the copper foil circuits and the eyelet with solder, and one of the copper foil circuits and the eyelet are provided. A printed wiring board is shown in which the eyelets are electrically connected by solder.

[The problem that the idea aims to solve]

In the prior art described above, in the case of the one shown in FIGS. 5 and 6, when using dip solder from the bottom side, the solder 6 is only filled up to the position indicated by the broken line in FIG. Due to the difference in thermal expansion caused by the change, there is a problem in that the copper foil tends to break, called a shoulder crack, at the boundary between the solder 6 and the copper foil circuit 2, and at the joint between the bottom copper foil 4 and the copper foil 2 on the top surface. be.

To prevent this shoulder crack,
As shown in the figure, it is effective to perform additional soldering from the top surface of the board 1, but this increases the number of soldering steps, resulting in a decrease in work efficiency.

Here, as a method for electrically connecting the copper foil circuits on both sides without causing the aforementioned shoulder cracks and reducing work efficiency, it has been considered to fill the aforementioned through holes 5 with a conductive material such as silver. However, the double-sided wiring board using this method is
It has the disadvantage that it is inferior to the through-hole plating described above in terms of reliability and performance, is limited to a specific range of use, and lacks versatility.

In addition, in the case of the one shown in Fig. 7, since the eyelet 8 is used, it is necessary to swage it after inserting it into the hole 7, which has the disadvantage that a special machine is required to insert the eyelet 8. If the eyelet 8 is securely caulked, both copper foil circuits 2 and 3 can be connected using only dip solder 9 to the position indicated by the broken line in the same figure, but due to aging or thermal changes, the eyelet 8 and There is a problem that the contact with the copper foil circuit 2 on the top surface becomes unstable and additional soldering is required as shown in the figure.Furthermore, in mass production, soldering including additional soldering must be performed uniformly. This method has disadvantages in that it is difficult to apply the solder 9 to each double-sided wiring board, causing variations in the filling status of the solder 9 for each double-sided wiring board, and resulting in a decrease in quality.

Furthermore, in the method described in the above-mentioned publication, in order to use a conductor or a resistive component as part of the connection part, an eyelet is inserted and the conductor or resistive component is attached to an insulating board with adhesive in advance, and then soldered as described above. Both ends of the conductor, etc. are electrically connected to the copper foil circuit and the eyelet, which increases the number of steps, takes a long time, and reduces work efficiency.

This invention was made in consideration of such problems of the conventional technology, and its purpose is to facilitate the insertion and attachment of the connecting body to the board.
To provide a double-sided wiring board that can be soldered without causing shoulder cracks or reducing work efficiency, and is excellent in mass production without causing variations in solder filling.

[Means to solve the problem]

In order to achieve the above object, the double-sided wiring board of this invention includes an insulating substrate, copper foil circuits formed on both the upper and lower surfaces of this substrate, and a transparent portion of the substrate including both copper foil circuits. a conductive connecting body that is inserted into the through hole from above and has a solder entry path formed in the vertical direction; and a sloped part for guiding insertion into the through hole formed at the bottom of the connecting body. , for positioning the connecting body, which is formed at the upper end of the sloping part and engages with the copper foil circuit on the upper surface or the lower surface of the board. and solder that fills the entry path and connects both copper foil circuits.

[Effect]

According to the above-mentioned configuration, the connecting body is inserted into the through hole of the insulating substrate from above, the step part is brought into contact with the copper foil circuit on the top surface, and the claw body of the connecting body is directly attached to the bottom surface of the board or the copper foil circuit on the bottom surface. By engaging through
The connecting body is positioned on the substrate without temporary fixing with an adhesive or the like, and at this time, insertion into the through hole is guided by the inclined portion at the bottom of the connecting body, so that the connecting body can be easily inserted into the through hole.

Then, if you solder the connection body from the bottom side,
The molten solder moves up the entry path of the connection body due to surface tension, and the solder fills the stepped opening of the entry path, and the copper foil circuits on both sides are electrically connected by the solder and the connection body. .

〔Example〕

Next, this invention will be described in the first part showing its practical example.
This will be explained in detail with reference to FIGS.

First, FIG. 1 and FIG. 2 showing one embodiment will be explained.

In FIG. 1, 10 is an insulating substrate, 11, 12
are copper foil circuits formed on the upper and lower surfaces of the substrate 10, 13 is a through hole made through the portion including the copper foil circuits 11 and 12 on both sides, 14 is a hole for fitting a connecting body, which will be described later, and 15 is a through hole. An electrically conductive connecting body whose right side is open and a groove-shaped intrusion path 16 of a predetermined width is formed in the vertical direction, and whose lower half is inserted into the through hole 13; a stepped portion 18 formed in communication with 16 and in contact with the copper foil circuit 11 on the upper surface;
20 is a claw body that is integrally formed at the tip of the inclined portion 19 at the lower end of the connecting body 15 and engages with the lower surface of the copper foil circuit 12 or the lower surface of the board 10 to position the connecting body 15; This joint is integrally provided at the right end of the upper half, and a U-shaped connecting body 21 is provided between adjacent connecting bodies 15, and the upper end of the connecting body 21 is connected to the joint 20 of the adjacent connecting bodies 15. A plurality of connecting bodies 15 are connected together by being joined together.

When only one connecting body 15 is used, cut the joint 20 at the dashed-dotted line in FIG. By inserting the connection body 15 into the hole 13, the stepped portion 17 comes into contact with the copper foil circuit 11, and the claw body 18 engages with the copper foil circuit 12 to position the connection body 15. After that, the connection body 15 is soldered from the bottom side. As a result, as shown in FIG. 2, the molten solder 22 rises up the intrusion path 16 due to surface tension, and the solder 22 is further filled up to the part of the intrusion path 16 that opens into the stepped portion 17, and the connection is completed. body 15
Solder 22 is also applied to the lower end of the board, and both the copper foil circuits 11 and 12 are connected by the solder 22 and the connecting body 15 to form a double-sided wiring board 23.

In addition, if a plurality of connecting bodies 15 are connected as described above, a large number of connecting bodies 15 can be manufactured at once, and the required number of connecting bodies 15 can be soldered while being connected. You can also.

Next, FIGS. 3 and 4 show other embodiments.
The diagram will be explained.

In those drawings, the same symbols as in FIGS. 1 and 2 indicate the same things, and
The difference from the figure is that a protrusion 24 is formed approximately at the center of the inside of the front surface of the connecting body 15.

And another single-sided wiring board 27 in which a copper foil circuit 26 is formed on one side of the double-sided wiring board 23 and the insulating substrate 25.
When connecting with the insertion part 28 of the single-sided wiring board 27
By inserting the copper foil circuit 26 into the entry path 16 of the connecting body 15 as shown in FIG. 3 with the copper foil circuit 26 facing the protrusion 24 side, as shown in FIG. The side surface of the connecting body 15 comes into contact with the rear inner surface of the connecting body 15, and the intrusion path 16 is narrowed to the gap between the copper foil circuit 26 and the front inner surface of the connecting body 15 by the protrusion 24, but the intruding path 16 is secured, Connection body 15
By soldering from the bottom side, the molten solder 22 rises through the narrow intrusion path 16, the intrusion path 16 is filled with solder 22, and the copper foil circuits 11, 12, and 26 are bonded by the solder 22 and the connecting body 15. are electrically connected.

[Effect of idea]

Since this invention is configured as described above, it produces the effects described below.

By simply soldering the connecting body inserted into the through-hole of the insulating board from the bottom side, the solder can be filled up to the entry path of the connecting body and the open part of the stepped part of the penetration path. This makes it possible to electrically connect copper foil circuits on both sides, eliminating the occurrence of shoulder cracks and the need for additional soldering, and reducing the number of manufacturing steps for double-sided wiring boards. This simplifies the work in each process, and allows high-quality wiring boards with uniform solder filling to be provided in large quantities and at low cost.

Furthermore, the inclined part formed at the lower part of the connecting body can guide the insertion of the connecting body into the through hole, and the claw body at the upper end of the inclined part can be engaged with the lower surface of the board directly or via a copper foil circuit. Since the connecting body can be positioned on the board, it can be securely fixed simply by inserting the connecting body into the through hole, and there is no need to use adhesive or the like for temporary fixing, making the work of inserting the connecting body very easy. It is what it is.

[Brief explanation of the drawing]

1 to 4 show an embodiment of the double-sided wiring board of this invention, FIGS. 1 and 2 are a perspective view and a cut front view showing the manufacturing process of one embodiment, and FIGS. 3 and 4 are a perspective view and a cut right side view showing the manufacturing process of another embodiment, FIGS. 5 and 7 are a plan view and a cut front view of a conventional double-sided wiring board, respectively, and FIG. 6 is a cut front view of FIG. It is a diagram. 10... Insulating board, 11, 12... Copper foil circuit,
13...Through hole, 15...Connection body, 16...Intrusion path, 17...Step part, 23...Double-sided wiring board.

Claims (1)

[Scope of utility model registration request] an insulating substrate, a copper foil circuit formed on both upper and lower surfaces of the substrate, a through hole formed in a portion of the substrate including both the copper foil circuits, and a solder inserted into the through hole from above. an electrically conductive connecting body in which an intrusion path is formed in the vertical direction; a sloped portion for guiding insertion into the through hole formed at a lower part of the connecting body; a stepped portion formed and in contact with the copper foil circuit on the upper surface; a claw body for positioning the connection body formed on the upper end of the slope portion and engaged with the copper foil circuit on the lower surface or the lower surface of the substrate;
A double-sided wiring board comprising: solder filled in the intrusion path and connecting both the copper foil circuits.