JP2000277870A - Printed circuit board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To constitute a printed circuit board, wherein the short circuit or leakage can be surely prevented in any environment. SOLUTION: In a printed circuit board 1 with circuit patterns formed on the substrate surface, open holes 8 for preventing scattered contaminants from forming bridges are formed between the circuit patterns, in the form of elongated slits substantially crossing a straight line passing through the adjacent circuit patterns 2, 3 and a plurality of photocouplers 11 to be mounted components are arranged in substantially a straight line, so as to step over the slit-like formed single open holes 8.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printed circuit board on which a circuit pattern is formed on the surface of a board and on which electronic components and the like are mounted, and which can reliably maintain an insulation state between adjacent circuit patterns. A printed circuit board configured as described above.

[0002]

2. Description of the Related Art Conventionally, a printed circuit board having a circuit pattern formed on the surface of the board is known, and has been configured by mounting various electronic components and mounting components such as semiconductor elements on the circuit pattern of the board. . In such a printed circuit board, in order to prevent solder from adhering to a portion other than a necessary portion, or to prevent a short circuit between different circuit patterns due to a foreign material adhering to the surface of the substrate, the printed circuit board is used. A protective film such as a solder resist was formed on the surface to cover the circuit pattern. Then, a land portion is formed on the mounting surface of the mounting component on the surface of the substrate where the circuit pattern is exposed without being covered with the protective film, and a lead of the mounting component is connected to the land by soldering or the like. Was. Further, in the printed circuit board on which the mounting components are mounted on the board as described above, the respective circuit patterns are arranged adjacently for reasons such as wiring many circuit patterns in a limited space. In many cases, for example, a circuit pattern to which an input-side lead of a mounted component is connected and a circuit pattern to which an output-side lead is connected are arranged adjacent to each other, or a circuit pattern on a ground side and a circuit on a high voltage side in a power supply circuit. The pattern was arranged adjacently.

[0003]

As described above, between the input-side circuit pattern and the output-side circuit pattern, or between the ground-side circuit pattern and the high-voltage-side circuit pattern, which are arranged adjacent to each other. It is necessary to ensure the insulation state, but since the solder is exposed at the land portion of each circuit pattern, foreign matter is present between the input side and the output side or between the ground side and the high voltage side. When they adhere, there is a possibility that both patterns may be electrically short-circuited or leak. When it is important for the mounted component to maintain an insulation state between the input side and the output side, for example, as in a photocoupler, or when the voltage on the high voltage side of the power supply circuit is high, there is a gap between the two patterns. In particular, it is necessary to maintain the insulation state. Further, when the printed circuit board is incorporated in a device installed in an environment where fibrous foreign matter such as fly waste is scattered, such as in a textile machine factory, fly waste and the like easily adhere to the substrate surface. As a result, the probability of occurrence of a short circuit or leakage increases. In view of the above, the present invention provides a printed circuit board so that a short circuit or a leak can be reliably prevented even in such an environment.

[0004]

The present invention uses the following means in order to solve the above problems. That is, in the first aspect, in the printed circuit board having the circuit pattern formed on the substrate surface, an opening hole is formed between adjacent circuit patterns so that the scattered foreign matter does not form a bridge.

According to a second aspect of the present invention, in the printed circuit board, the opening is formed in an elongated slit shape in a direction substantially orthogonal to a straight line connecting adjacent circuit patterns.

According to a third aspect of the present invention, in the printed circuit board, a plurality of mounted components are arranged in a substantially straight line so as to straddle the single opening formed in a slit shape.

[0007]

Embodiments of the present invention will be described with reference to the accompanying drawings. 1 is a partial plan view showing one surface side of the printed circuit board of the present invention, FIG. 2 is a partial plan view showing the other surface side of the printed circuit board, and FIG. 3 is a partial cross-sectional view showing the same.

A printed circuit board according to the present invention will be described with reference to FIGS. The printed circuit board 1 is, for example, a double-sided board having a circuit pattern formed on both sides. On one side 1a of the printed circuit board 1, for example, electronic components such as a plurality of photocouplers 11 constituting a signal circuit are provided. Has been implemented. On the other side 1b of the printed circuit board 1, an input circuit pattern 2 and an output circuit pattern 3 connected to the photocoupler 11 are formed. On the other side 1b of the printed circuit board 1, a protective film 6 such as a solder resist is formed, and covers the input / output side circuit patterns 2.3.

The printed circuit board 1 has an input lead mounting hole 7a for inserting an input (light emitting) lead 11a of the photocoupler 11 and an output lead mounting hole 7b for inserting an output (light receiving) lead 11b. The input-side land pattern 2a is formed in the input-side lead mounting hole 7a forming portion of the input-side circuit pattern 2, and the output-side land portion 3a is formed in the output-side lead mounting hole 7b forming portion of the output-side circuit pattern 3. Are formed. The input / output land portions 2a and 3a are exposed without being covered by the protective film 6.

The input side (light emitting side) lead 11a of the photocoupler 11 is inserted into the input side lead mounting hole 7a from one side 1a, and is connected to the input side land 2a formed on the other side 1b. The input-side circuit pattern 2 and the input-side (light-emitting-side) lead 11a are connected. On the other hand, the output side (light receiving side) lead 11b of the photocoupler 11 is inserted into the output side lead mounting hole 7b from one side 1a,
The output-side circuit pattern 3 is connected to the output-side (light-receiving-side) lead 11b at an output-side land portion 3a formed on the other surface side 1b.

The plurality of input-side lead mounting holes 7 are formed.
a and the output-side lead mounting holes 7b are arranged side by side in a line, and are disposed adjacent to each other. An opening 8 penetrating the printed circuit board 1 is provided between the input-side lead mounting hole 7a and the output-side lead mounting hole 7b. The opening 8 is formed in an elongated slit shape and is opened between the plurality of input / output side lead mounting holes 7a and 7b. The photocoupler 11 is mounted on the one surface 1a of the printed circuit board 1 so as to straddle the opening 8, and the plurality of photocouplers 11 are arranged substantially linearly.

Here, the photocoupler 11 is an electronic component that transmits and receives signals in the form of light using a set of a light emitting element and a light receiving element, and is connected to the input side (light emitting side) of the photocoupler 11. Since it is electrically insulated from the output side (light receiving side), it is often used in places where it is necessary to suppress electrical noise. Therefore, in the mounted components such as the photocoupler 11, the input side (light emitting side) lead 11a
It is important to maintain an insulating state between the output side (light receiving side) lead 11b and the output side (light receiving side) lead 11b. It should be noted that the input side circuit pattern 2 and the output side circuit pattern 3 sandwiching the opening 8 are not subject to tracking even when a high voltage is applied in a state of being exposed to a high humidity atmosphere without forming the opening 8. The patterns are separated by a distance large enough to prevent a short circuit between the patterns 2 and 3 due to the phenomenon.

However, when the printed circuit board 1 on which the photocoupler 11 and the like are mounted is incorporated in a device installed in a textile machine factory or the like in an environment where fibrous foreign matter such as fly waste is scattered, Fly fly or the like adheres to the other surface side 1b of the printed circuit board 1, and the input land portion 2a and the output land portion 3a formed on the other surface side 1b are connected by the attached fly waste or the like, There is a possibility that the input and output sides of the photocoupler 11 may be electrically short-circuited (short-circuited) or leak.

Therefore, in the present invention, as described above,
The opening 8 is opened between the input side land 2a and the output side land 3a so that foreign matter such as fly cotton does not adhere to the other side 1b of the printed circuit board 1. The size of the opening 8 is such that both edges are not connected to each other by foreign matter such as flying fly.
A size of 5 mm or more is required, and a size of about 2.0 mm is preferable. That is, the input side land 2
printed circuit board 1 between a and the output side land portion 3a
On the other surface side 1b, an opening hole 8 penetrating the printed circuit board 1 is formed, so that even if foreign matter such as fly fly scatters between the adjacent input / output land portions 2a and 3a, The other side 1b does not have a surface to which foreign matter only adheres, and the foreign matter cannot adhere. As a result, the input / output land portions 2a and 3a are not connected by the foreign matter, and the adjacent input side circuit pattern 2 and output side circuit pattern 3 are electrically short-circuited (short) or leaked. Can be prevented.

Since the photocoupler 11 is mounted on the printed circuit board 1 so as to straddle the opening 8,
An electrical short circuit between the input side (light emitting side) lead 11a and the output side (light receiving side) lead 11b of the photocoupler 11, that is, between the input side and the output side, or leakage may occur. Thus, the insulation state can be reliably maintained, the normal operation of the photocoupler 11 can be reliably maintained, and the reliability of the printed circuit board 1 can be improved.

Further, the opening 8 is formed in an elongated slit shape, and a plurality of photocouplers 1 are provided so as to straddle the opening 8.
1 are arranged in a substantially straight line so that the input / output circuit patterns 2 adjacent to each other in the plurality of photocouplers 11 are arranged.
-The insulation state between the three can be maintained collectively. Furthermore, the input / output circuit patterns 2 adjacent to each other as compared with the case where the opening holes 8 are formed in the mounting portions of the photocouplers 11 respectively.
-The insulation distance between the three can be configured to be long, and the insulation state can be maintained more reliably.

When an opening is formed between adjacent circuit patterns, not only the photocoupler 11 but also a connector having a plurality of leads, a semiconductor element, or other electronic components are mounted so as to straddle the opening. However, the insulation between the adjacent circuit patterns of these mounted components can be reliably maintained. Further, these mounted components are transferred to the printed circuit board 1.
The opening hole 8 as described above can be formed either when mounted on only the one surface side 1a or only on the other surface side 1b, or when mounted on both the one surface side 1a and the other surface side 1b. . Further, the printed circuit board 1 may be configured as a single-sided board or a multilayer board as long as a circuit pattern is formed on the board surface.

A power supply circuit is formed on the printed circuit board 1. For example, a ground side circuit pattern 4 is formed on the other side 1b, and a high voltage side circuit pattern 5 is formed on the one side 1a. . Since the protective film 6 is formed on one side 1a and the other side 1b of the printed circuit board 1, the ground side circuit pattern 4 and the high voltage side circuit pattern 5 are covered with the protective film 6. The land portion 4 on which the ground-side circuit pattern 4 is exposed is provided on the ground-side circuit pattern 4.
a is formed on both the first side 1a and the other side 1b, and the high voltage side circuit pattern 5 has a land portion 5a on which the high voltage side circuit pattern 5 is exposed, on both the first side 1a and the other side 1b. Is formed. The land portion 4a of the ground side circuit pattern 4 and the land portion 5a of the high voltage side circuit pattern 5 are disposed adjacent to each other, and the above-described opening hole 8 is provided between the land portion 4a and the land portion 5a. As shown in the figure, an opening hole 9 penetrating the printed circuit board 1 is opened. The land 4a and the land 5a sandwiching the opening 9 are not formed by the tracking phenomenon even when a high voltage is applied in a high humidity atmosphere or the like without forming the opening 9. The lands 4a and 5a are separated by a distance large enough to prevent a short circuit from occurring.

As described above, the opening 9 can be formed between the ground side circuit pattern 4 and the high voltage side circuit pattern 5 which constitute the power supply circuit and are arranged adjacent to each other.
As a result, similarly to the case of the above-described opening hole 8, the ground-side circuit pattern 4 and the high-voltage side circuit pattern 5 are electrically short-circuited (short-circuited) or leak due to attachment of foreign matter such as fly cotton. Can be prevented, the insulation state can be reliably maintained, and the reliability of the printed circuit board 1 can be improved. Further, the insulation distance between the ground side circuit pattern 4 and the high voltage side circuit pattern 5 can be configured to be long, and the insulation state can be maintained more reliably. The opening 9 formed to reliably maintain the insulating state works particularly effectively when the voltage of the high-voltage side circuit pattern 5 of the power supply circuit is high.

[0020]

According to the present invention, the printed circuit board having the above-described configuration has the following effects.
First, in a printed circuit board having a circuit pattern formed on the substrate surface, an opening hole is formed between adjacent circuit patterns so that scattered foreign matter does not form a bridge. Even if it scatters between adjacent circuit patterns, foreign matter cannot adhere to the surface of the printed circuit board. As a result, the adjacent circuit patterns are not connected by the foreign matter, and it is possible to prevent the path patterns from being electrically short-circuited or leaking. By forming the opening holes in this manner, the insulation state between adjacent circuit patterns that need to be maintained in an insulation state can be reliably maintained, and the reliability of the printed circuit board can be improved.

Furthermore, in the printed circuit board, since the opening is formed in an elongated slit shape in a direction substantially perpendicular to a straight line connecting the adjacent circuit patterns, the input side of the mounting component is connected to the input side of the mounted component. It is possible to prevent electrical short-circuiting and leakage between the output side and the insulation state can be reliably maintained, and the normal operation of the mounted components can be reliably maintained. The reliability of the printed circuit board can be improved. Also, since the scattered foreign matter can be reliably prevented from adhering between the adjacent circuit patterns, the foreign matter is more reliably prevented from forming a bridge between the adjacent circuit patterns, and the insulating state is reliably maintained. It is possible to do.

Further, in the printed circuit board, a plurality of mounted components are arranged in a substantially straight line so as to straddle the single opening formed in the slit shape.
The insulation state between the input / output circuit patterns adjacent to each other can be maintained collectively. In addition, each photo coupler 11
The insulation distance between adjacent input / output circuit patterns can be configured to be longer than when opening holes 8 are formed in the respective mounting portions, and the insulation state can be maintained more reliably. Further, as compared with a case where a slit-shaped opening hole is formed for each mounted component, the interval between the mounted components can be reduced, and the entire substrate can be made compact.

[Brief description of the drawings]

FIG. 1 is a partial plan view showing one surface side of a printed circuit board according to the present invention.

FIG. 2 is a partial plan view showing the other side of the printed circuit board.

FIG. 3 is a partial sectional view showing the printed circuit board.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Printed circuit board 1a One side 1b Other side 2 Input side circuit pattern 2a Input side land part 3 Output side circuit pattern 3a Output side land part 4 Ground side circuit pattern 5 High voltage side circuit pattern 7a Input side lead mounting hole 7b Output side Lead mounting hole 8.9 Opening hole 11 Photocoupler 11a Input side (light emitting side) lead 11b Output side (light receiving side) lead

Claims (3)

[Claims] 1. A printed circuit board having a circuit pattern formed on a surface of the board, the printed circuit board having an opening formed between adjacent circuit patterns to prevent scattered foreign matter from forming a bridge. 2. The printed circuit board according to claim 1, wherein the opening is formed in an elongated slit shape in a direction substantially orthogonal to a straight line connecting adjacent circuit patterns.
A printed circuit board according to claim 1. 3. The printed circuit board according to claim 2, wherein a plurality of mounted components are arranged in a substantially straight line so as to straddle a single opening formed in a slit shape. Printed circuit board.