JP2544459Y2 - Printed circuit board - Google Patents

Description

[Technical field] The present invention relates to a printed circuit board used for a power supply device such as a switching regulator and an adapter.

[Problems to be solved by conventional technology and device]

As a power supply for obtaining a required DC voltage from a commercial AC power supply, there are a switching regulator, an adapter, and the like.

Each of these devices mainly outputs a voltage of 50 volts or less, and supplies a large current of several amps to several tens of amps depending on the device. In order to output this DC voltage, a printed circuit board on which required functional components are mounted is incorporated in the apparatus.

In general, a printed circuit board has electronic components mounted on an insulating substrate such as a phenol resin or a glass epoxy resin, and is electrically connected to a conductor pattern disposed on the surface of the insulating substrate by soldering or the like. Then, copper foil is used for the conductor pattern and usually has a thickness of about 35 μm.

In general, a large output current flows through a conductor pattern on a printed circuit board such as a switching regulator, particularly at a site of a final stage circuit.

However, there is a limit to the allowable current capacity of the conductor pattern. For this reason, in response to the increase in output current capacity, the pattern shape should be considered so that the conductor pattern area is as large as possible, and the conductor pattern should be connected to a lead wire with a large diameter to shunt the current. That is the current situation.

However, when the area of the conductor pattern is increased,
There is a problem that the solder plating becomes easy to flow, the thickness of the solder layer becomes thin, and as a result, it becomes difficult to flow a large current.

The present invention has been made in view of the above-described problems in the prior art, and has as its object to provide a printed circuit board that can cope with an increase in current capacity without increasing manufacturing costs. To provide.

[Means for solving the problem]

In order to achieve the above object, in the printed circuit board of the present invention, there is provided a printed circuit board formed by forming a conductor pattern through which a current flows on a substrate and forming a resist thereon. A plurality of strip-shaped conductor exposed portions which are long in the length direction of the conductor pattern partitioned by a resist are provided on the upper portion, and the plurality of conductor exposed portions are provided in one conductor pattern in a width direction of the conductor pattern. And three or more are arranged in parallel and arranged at intervals shorter than the length of the conductor exposed portion in the length direction of the conductor pattern, and between two conductor exposed portions adjacent in the length direction. The seam faces the conductor exposed portion adjacent thereto in the width direction, and the plurality of conductor exposed portions are subjected to solder plating, and the solder plating is located on all cross sections in the width direction of the conductor pattern. Ri, current capacity of the conductor pattern is a printed circuit board, characterized by being substantially increased is provided.

[Action]

When solder plating is applied to the exposed conductor portion separated by the resist, the peripheral edge of the solder that contacts the edge of the resist,
Attempts to build up due to surface tension.

Due to the swelling of the solder, the capacity of the solder to be plated is increased, and the conductor exposed portion provided on the conductor pattern is divided and provided. In comparison, the total capacity to be soldered is larger, and thus the current capacity is substantially increased.

[Specific Example] Hereinafter, a printed circuit board according to the present invention will be described with reference to the accompanying drawings.

FIG. 1 is a perspective view in which a part of a power supply printed circuit board mounted on a switching regulator is crushed, for example.

In FIG. 1, reference numeral 1 denotes a printed circuit board. The front side (front side) of the figure is a pattern surface, and the other side (back side) of the figure is a surface on which required electronic components are mounted.

On the substrate 2, a conductor pattern 3 for leading the output current of the switching regulator is provided for each of a positive electrode and a ground electrode, and an output lead wire 10 connected to each is led to the outside. The conductor pattern 3 is formed in a predetermined pattern using a copper foil, and a resist 4 is applied on the conductor pattern 3. The resist 4 is applied, for example, so that the conductor pattern is exposed in an elongated rectangle so as to expose the conductor pattern. The exposed portion 6 is provided on the conductor pattern 3 by being divided into several parts. Note that, at the end of the conductor pattern 3 to which the output lead wire 10 is connected, a conductor exposed portion 9 for an electrode is provided, and a through hole 7 is formed.

The printed circuit board 1 on which predetermined electronic components are mounted on the substrate 2 is passed through a device such as an automatic solder tank, and the pattern surface is plated with solder. At this time, the solder 5 adheres to the conductor exposed portion 6 on the conductor pattern 3, and this state is shown in FIG.

FIG. 2 is a sectional view showing a part of the conductor exposed portion 6 on the conductor pattern 3. In FIG. 2, the solder 5 is adhered to the exposed conductor 6 and at the boundaries 16, 16 of the conductor pattern 3 partitioned by the resist 4, that is, the solder 5
Swells at the edge of the surface due to its surface tension. Due to this surface tension, the total amount of solder that swells on the exposed conductor 6 on the conductor pattern 3 is larger than when the exposed conductor 6 is not divided, that is, when the entire surface of the conductor pattern 3 is plated with solder. Then, the current capacity on the conductor pattern 3 is substantially increased.

In this specific example, as shown in FIG. 3, the shape of the conductor exposed portion 6 is 15 to 20 mm in length and 1.5 to 2 mm in width, and is provided separately on the conductor pattern 3. In FIG. 3, the adjacent exposed portions 6 arranged at intervals in the vertical direction are alternately arranged in the left and right direction, and the vertical stitch in the left and right direction becomes the center of the adjacent exposed portion 6. ing. Thereby, the current capacity of the conductor pattern 3 can secure a current capacity of about 10 amps per 10 mm width.

Thus, the output current derived from the conductor pattern 3 is:
Through the through hole 7 in which the electrode conductor exposed portion 9 is plated with solder, it is supplied to the outside from the output lead wire 10 which is electrically connected.

Note that, in FIG. 1, a land cutout portion 14 that is partially cutout is provided in a through hole 13 inside a land 15 provided in another conductor pattern 12. This part is notched in order to prevent the through hole 13 from being filled with solder when solder plating when soldering without connecting anything and connecting lead wires etc. in a later process. is there.

As described above, one specific example of the printed circuit board according to the present invention has been described. However, the present invention is not limited to the specific example, and various changes and modifications can be made without departing from the scope of the present invention.

For example, the shape and size of the exposed conductor 6 and the number of exposed conductors 6 divided on the conductor pattern 3 can be freely designed.

[Effect of the invention]

Since the present invention has the above-described configuration, the following operational effects can be obtained.

By providing a conductor exposed portion divided by a resist on the conductor pattern and applying solder plating to the exposed portion, a printed circuit board corresponding to a large current capacity is provided. In addition, a plurality of exposed conductors are arranged in three or more rows in one conductor pattern, and a joint between two exposed conductors in the longitudinal direction is opposed to the exposed conductor in the width direction. Regardless of the width direction cross section of the conductor pattern, the exposed portion of the conductor is plated with solder, so that the cross-sectional area of the conductive pattern increases over substantially the entire length of the conductive pattern, and the current flowing through the conductive pattern can be increased.

[Brief description of the drawings]

FIG. 1 is a partially broken perspective view showing a specific example of a printed circuit board according to the present invention. FIG. 2 is a sectional view of a main part of FIG. FIG. 3 is a plan view of a main part of FIG. DESCRIPTION OF SYMBOLS 1 ... Printed circuit board 2 ... Board 3 ... Conductor pattern 4 ... Resist 5 ... Solder 6 ... Conductor exposed part 7 ... Through hole 10 ... Output lead wire 16 ... Boundary part

Claims (1)

(57) [Scope of request for utility model registration] 1. A printed circuit board comprising a conductive pattern on which a current flows on a substrate, and a resist formed on the conductive pattern, wherein a length of the conductive pattern divided by the resist is formed on the conductive pattern. A plurality of strip-shaped conductor exposed portions that are long in the direction are provided in a divided manner, and the plurality of conductor exposed portions are arranged such that three or more in one conductor pattern are arranged in parallel in the width direction of the conductor pattern, and The conductor exposed portions are arranged in the length direction at intervals shorter than the length of the conductor exposed portions, and a seam between the two conductor exposed portions adjacent in the length direction is formed in the width direction in the conductor exposed portion adjacent thereto. The plurality of exposed conductor portions are plated with solder, and the solder plating is located on all cross sections in the width direction of the conductor pattern, and the current capacity of the conductor pattern is substantially increased. Printed circuit board, characterized in that there.