JP4702174B2 - Printed circuit board control device - Google Patents

Description

  The present invention relates to pattern printing of a fuse formed of a patterned conductor in a printed circuit board control device of an electronic circuit device.

  Conventionally, in an electrical device that is connected to a commercial power source and used when an overcurrent flows, the current fuse is blown to prevent burning of electric parts or the like and to prevent electric shock. The current fuse is installed in a circuit through which the entire current of the device flows, and is blown when an excessive current such as 130% or 150% flows from the rated current of the device.

  In the example of the conventional electronic circuit as shown in FIG. 10, in the circuit connected by the 100V commercial power supply 20 and the connector 10, the electronic member such as the capacitor 12, the ZNR 11 and the transformer 13 are connected in parallel to the secondary side. The current fuse 15 is connected to a circuit where all currents are concentrated, and these circuits are formed by a wiring pattern of a printed circuit board.

  There are two types of the current fuse 15, and the role of the fuse is given by using an electronic component such as a tube-type fuse in which a line fuse is enclosed in a glass tube and by making the wiring pattern thinner than other patterns. A pattern fuse is generally used.

  The tube-type fuse has terminal fittings at both ends, and has a structure in which a fusible substance is housed in a transparent glass tube, which is soldered to a printed circuit board via a fuse holder, and the overcurrent is cut off by the fuse. To determine whether overcurrent flows through these current fuses, they can be visually checked, removed from the fuse holder to check the details, or using a measuring instrument such as a tester, I was judging.

Further, as a conventional technique that makes it easier to understand the fusing state by visual observation, a background pattern having a lighter color than the color of the printed circuit board is printed on a portion of the glass tube fuse that faces the glass tube (for example, Patent Document 1). reference). Thus, a configuration is described in which confirmation can be easily performed without removing the fuse from the printed circuit board.
Japanese Patent Laid-Open No. 11-17293

  However, in the conventional configuration, when electronic parts such as a glass tube are used, it has an advantage that the fusing state is easy to understand visually, but on the other hand, due to the problem that the cost is increased and the fuse holder having a glass tube size and height. There was a problem that it was difficult to make the wiring board compact by taking up space.

  On the other hand, when a pattern fuse that is frequently used in recent years is used as a current fuse, there is a problem that variation occurs in the manner of fusing depending on the shape of the pattern fuse, and further, variation occurs depending on the magnitude and timing of the overcurrent flow.

  When the above variations occur, if the pattern fuse shape part is blown cleanly, on the other hand, there are various cases, such as a case where only a part of the pattern fuse is blown out. Sometimes I missed a blown fuse.

  For this, the printed wiring board has a dark brown or brown color, and the resist printing that protects the copper foil generally has a dark green or other dark color. Was also one of the causes.

As a result, it takes time for the service person in charge of repair to notice that the pattern fuse is blown, or without knowing the cause of the blow (for example, applying 200 V despite the 100 V rating) In some cases, since the printed circuit board was replaced, the pattern fuse was repeatedly blown.

  SUMMARY OF THE INVENTION The present invention solves the above-described conventional problems, and provides a printed circuit board control device that can easily check whether or not a fuse is blown when a costly pattern fuse is used. The purpose is to do.

In order to achieve the above object, the printed circuit board control apparatus of the present invention includes a wiring pattern in which a commercial power source and an electrical component are formed in a closed circuit on a printed circuit board, and at least a part of the wiring pattern as another part. A printed circuit board having a pattern fuse formed by fusing the thin wiring pattern when the electrical component or the closed circuit is short-circuited. A printed pattern having a lighter color than the color is applied, and this printed pattern has a portion that is not printed by being cut out along the thin wiring pattern shape so as not to cover the pattern fuse shape of the thin wiring pattern. .

Thus, without destabilizing the blowing of the pattern fuse, because occurs blown traces printed pattern at the same time when the pattern fuse is blown, be determined by clearly visually locations are blown by the difference in contrast It becomes possible. Therefore, an effect equivalent to visibility can be obtained without using a current fuse such as a glass tube which is costly.

Further, the printed circuit board control apparatus of the present invention includes a printed circuit board that constitutes a double-sided print having both front and back copper foils disposed therein, a shallow protective case with an open top surface that embeds the printed circuit board, and a filling in the protective case A moisture-proof material such as urethane resin having transmission visibility that protects the entire circumference of the printed circuit board against moisture, a wiring pattern in which a commercial power source and electrical components are formed in a closed circuit on the printed circuit board, and the wiring pattern A printed circuit board on which at least a part is formed with a wiring pattern thinner than the other part, and a pattern fuse for fusing the thin wiring pattern when the electrical component or the closed circuit is short-circuited. Constructed on the open side of the upper surface of the protective case, brighter than the color of the printed circuit board on the thin wiring pattern Subjected to have color printing pattern, the printing pattern, so as not suffer to the shape of the pattern fuse the fine wiring pattern, and has a portion not to be printed hollowed out along the narrow wiring pattern.

Thereby, even when the moisture-proof material is configured without making the fusing of the pattern fuse unstable, it is possible to clearly visually determine the location where the pattern fuse is blown.

The printed circuit board control device of the present invention applies a printed pattern having a lighter color than the printed wiring board substrate color on the pattern fuse, and the printed pattern does not cover the shape of the pattern fuse of the thin wiring pattern. In addition, since it has a part that is not printed by being cut out along a thin wiring pattern shape, the state of the pattern fuse is surely visually confirmed from the difference in contrast when the pattern fuse is blown without destabilizing it. can do.

According to a first aspect of the present invention, there is provided a wiring pattern in which a commercial power source and an electrical component are formed in a closed circuit on a printed circuit board, and at least a part of the wiring pattern is formed in a wiring pattern narrower than other portions, and the electrical component or the closed circuit during the short circuit, and a printed substrate provided with the pattern fuse to blow the fine wiring pattern, the bright color of the print pattern than the color of the printed circuit board applied over the narrow wiring pattern in the printed circuit board, the printed pattern It is so as not suffer to the shape of the pattern fuse the fine wiring pattern, by have a portion not to be printed hollowed out along the narrow wiring pattern, without destabilizing the blowing of the pattern fuse, cost Easy to check whether or not the pattern fuse is blown even when using a pattern fuse that does not cost It can be carried out.

The second invention, the print is filled with printed circuit board constitutes a double-sided printed decor table back double-sided copper foil, a shallow bottom of protective case with the top-surface opening to interior of said printed circuit board, and the protection in the case Moisture-proof material such as urethane resin that has permeation visibility that protects the entire circumference of the substrate against moisture, a wiring pattern in which a commercial power source and electrical components are formed in a closed circuit on the printed circuit board, and at least a part of the wiring pattern And a printed circuit board on which a pattern fuse is formed that melts the thin wiring pattern when the electrical component or closed circuit is short-circuited, and the pattern fuse is opened on the upper surface of the protective case of the printed circuit board. constitute the part side, facilities bright color of the print pattern than the color of the printed board on the narrow wiring pattern in the printed circuit board The printed pattern, so as not suffer to the shape of the pattern fuse the fine wiring pattern is one having a portion not to be printed hollowed out along the narrow wiring pattern, the control unit even over that moisture-proofed Without making the fusing of the pattern fuse unstable, the fusing status of the pattern fuse can be confirmed visually by the difference in contrast .

Following, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 is a plan view seen from the solder surface of a single-sided printed circuit board according to the first embodiment of the present invention, and FIG. 2 is a plan view after the pattern fuse of the printed circuit board is blown. .

  In FIG. 1, the printed circuit board 1 is often composed of an insulating plate having a dark color such as brown, brown, or dark green, and the parts on the back surface are connected to a 100 V power source at the locations indicated by the map 3. A map state in which electronic components such as the connector 10 and the ZNR 11, the capacitor 12, and the transformer 13 are connected and wired is shown, and a large number of lands 2 on which solder wires are inserted and soldered are arranged on the solder surface.

  The hatched portion (shaded portion) 4 is a wiring pattern printed with copper foil on one side of the printed circuit board 1, connecting between the terminal portions of each electronic component, and soldering at the land 2 for electrical connection. ing.

  By setting the width of the wiring pattern 4 to be narrower than the normal pattern width, the pattern fuse 4a can melt this pattern portion first when an overcurrent flows.

  The printed circuit board 1 is formed by attaching a copper foil on an insulating plate and performing an etching process to form a necessary wiring pattern 4, and then printing a resist for preventing corrosion and soldering of the copper foil. The land 2 is formed in a shape in which the soldering portion of the resist is removed.

The printed pattern 5 is set to a shape that completely covers the pattern fuse 4a. The print pattern 5 is printed with a lighter color than the color of the printed circuit board, and is set to a light color such as white or light aqua. In addition, the printing pattern 5 targeted by the present invention may be produced as a new plate exclusively for pattern printing, but usually white is often used as the printing ink for the map 3, so in the map printing, By sharing, it is possible to print the print pattern 5 in white without increasing the cost.

  The operation and action of the printed circuit board configured as described above will be described below.

  In FIG. 2, the pattern fuse 4a in the case where an overcurrent flows due to a short mode due to a component failure such as ZNR11 or capacitor 12, a breakdown mode of ZNR11 due to application of a double voltage of 200V, a rare short of the transformer 13, etc. The melted state is shown, the closed circuit is opened, and energization is stopped.

At this time, a part of the printed pattern 5 is peeled off due to the melting of the pattern fuse 4 a, and a burn mark at the time of the melting appears in the printed pattern 5 as a burn mark 6. Since the print pattern 5 is white and the burnout mark 6 is generally a dark target, it can be determined from the difference in contrast that the pattern fuse 4a is blown at a glance.

In order to more easily understand that there is a pattern fuse 4a in the wiring pattern, something like image the glass tube fuse on the shape of the pattern wiring and (not shown), "fuse next print pattern 5 "25" is added for easier understanding.

(Embodiment 2)
FIG. 3 is a plan view seen from the solder surface of the single-sided printed board in the second embodiment of the present invention, and FIG. 4 is a plan view after the pattern fuse of the printed board is blown.

In the printed pattern 5 of FIG. 3, a shape 5a that is cut out without printing is provided so as not to overlap the shape of the pattern fuse 4a. Other configurations are the same as those of the first embodiment, and detailed description thereof is omitted.

With the above configuration, it can be seen at a glance that the pattern fuse 4a is formed inside the print pattern 5, and when the pattern fuse 4a is blown by overcurrent, the shape of the pattern fuse of the print pattern 5 as shown in FIG. As a result, the burnout marks 6 of the copper foil spread to the surroundings, so that not only a serviceman but also a person who handles the board for the first time can easily know that the pattern fuse 4a exists in this wiring place and has blown out. I can confirm.

(Embodiment 3)
FIG. 5 is a plan view seen from the component side of a double-sided printed circuit board with copper foil disposed on the front and back according to the third embodiment of the present invention, and FIG. 6 is a plan view after the pattern fuse of the printed circuit board is blown out. FIG. 7 shows a cross-sectional view when the printed circuit board is moisture-proof treated.

A broken line portion 4b in FIG. 5 represents a copper foil on the back surface wired on the solder surface, and a hatched portion 4c represents a copper foil wired on the component surface on the front surface in the figure. The printed pattern 5 is set to a shape that completely covers the pattern fuse 4a formed on the component surface.

  When a control device such as a washing machine is configured inside the upper operation surface of the device, it needs to be stored in a narrow space. For this reason, a double-sided printed circuit board is often used to make the printed circuit board compact. In addition, in products that use water or hot water, such as washing machines that tend to condense, if there is a possibility that the printed circuit board may malfunction, the printed circuit board is subjected to moisture-proof treatment to improve reliability. .

As shown in FIG. 7, the double-sided printed circuit board 30 for double-sided printing is housed in a protective case 14 made of an insulating plastic material or the like, and the steps of the protrusions 14a and 14b formed on the bottom of the protective case 14 This secures a gap between the solder surface and the bottom surface of the protective case.

  Further, the protective case 14 is formed of a shallow bottomed case having a substantially U-shaped cross section having an open portion 14c on the upper side, and a potting moisture-proof material 22 made of urethane resin or the like having transparent visibility is provided in the protective case 14. The entire peripheral surface including the front and back sides of the printed circuit board is completely filled with the potting moisture-proof material 22 by the potting injector 21 from the upper open part 14c, and the double-sided printed circuit board 30 is subjected to moisture-proof treatment, thereby providing a control case integrated controller It is composed.

The upper surface of the double-sided printed circuit board 30, that is, the open portion 14c side is a component surface side for inserting and fixing electronic components such as the ZNR 11, the capacitor 12, and the transformer 13, and the pattern fuse 4a and the printed pattern 5 are also on the same component surface side (that is, a protective case). (On the upper surface open part 14c side).

With the above configuration, even when the printed circuit board is placed in the protective case 14 and subjected to moisture-proofing by potting, in the case of the double-sided printed circuit board 30, visual confirmation can be performed by forming the pattern fuse 4a on the component surface side. It becomes. In addition, even if the printed pattern 5 surface is covered with urethane resin and the printed pattern 5 surface is difficult to see, if the pattern fuse 4a is blown, the burned-out pattern as shown by the burnout mark 6 in FIG. It becomes a black lump and stays in the potting moisture-proof treatment material, and the contrast with the printed pattern 5 becomes clear. Therefore, the melting of the pattern fuse 4a in the potting moisture-proof material 22 made of urethane resin having visible visibility is visually confirmed. can do.

(Embodiment 4)
FIG. 8 is a plan view seen from the component side of a double-sided printed board with copper foil disposed on the front and back according to the fourth embodiment of the present invention, and FIG. 9 is a plan view after the pattern fuse of the printed board is blown. Is shown.

In the printed pattern 5 in FIG. 8, a shape 5a that is cut out without printing is provided so as not to overlap the shape of the pattern fuse 4a. Other configurations such as the potting moisture-proof material 22 are the same as those in the third embodiment, and a detailed description thereof is omitted.

With the above configuration, even in the case of the double-sided printed circuit board 30, it is possible to visually confirm that the pattern fuse 4a is formed inside the printed pattern 5 by forming the pattern fuse 4a on the component surface side. When the pattern fuse 4a is blown by an overcurrent, the pattern fuse 4a is blown by the overcurrent because the burnout trace 6 of the copper foil spreads around, leaving the shape of the pattern fuse 4a of the printed pattern 5 as shown in FIG. Therefore, even a service person as well as a person handling a board for the first time can easily confirm that the pattern fuse 4a is in this wiring place and has blown.

  As described above, the printed circuit board control apparatus according to the present invention uses the pattern fuse, and even when the pattern fuse is blown due to overcurrent, the state can be easily confirmed by visual inspection. It is useful as a cost reduction plan for the equipment used.

The top view seen from the solder side of the single-sided printed circuit board in Embodiment 1 of this invention Plan view after the pattern fuse on the printed circuit board has melted The top view seen from the solder side of the single-sided printed circuit board in Embodiment 2 of this invention Plan view after the pattern fuse on the printed circuit board has melted The top view seen from the component surface of the double-sided printed circuit board in Embodiment 3 of this invention Plan view after the pattern fuse on the printed circuit board has melted Sectional view when the printed circuit board is moisture-proof The top view seen from the component surface of the double-sided printed circuit board in Embodiment 4 of this invention Plan view after the pattern fuse on the printed circuit board has melted Wiring diagram showing examples of conventional electronic circuits

DESCRIPTION OF SYMBOLS 1 Printed circuit board 2 Land 3 Map 4 Wiring pattern 4a Pattern fuse 5 Print pattern 14 Protective case 14c Open part 22 Moisture-proof material 30 Double-sided printed circuit board

Claims (2)

A wiring pattern in which a commercial power source and an electrical component are formed in a closed circuit on a printed circuit board, and at least a part of the wiring pattern is formed in a wiring pattern that is thinner than the other part, and when the electrical component or the closed circuit is short-circuited, and a printed circuit board forming a pattern fuse to blow the wiring pattern, the applied light colored print pattern than the printed circuit board colors on the fine wiring pattern on the printed board, the printed pattern, the fine wiring pattern of so as not suffer to the shape of the pattern fuse, a printed circuit board controller, characterized in that have a portion not to be printed hollowed out along the narrow wiring pattern. Printed circuit board with double-sided printing with front and back double-sided copper foil, shallow protective case with an open top surface that embeds the printed circuit board, and moisture-proof protection of the entire circumference of the printed circuit board by filling the protective case A wiring pattern in which a moisture-proof material such as urethane resin having transmission visibility, a commercial power supply and an electrical component are formed in a closed circuit on the printed circuit board, and a wiring pattern in which at least a part of the wiring pattern is thinner than other parts formed, at the time of short circuit of the electrical component or closed circuit, and a printed substrate provided with the pattern fuse to blow the fine wiring pattern, the pattern fuse constitutes a protective case open-top side of the printed circuit board, wherein the bright colors of the printed pattern than the color of the printed board on the narrow wiring pattern subjected in the printed board, the printed-Pas Over down is, as not subject to the shape of the pattern fuse the fine wiring pattern, a printed circuit board control apparatus characterized by having a portion not to be printed hollowed out along the narrow wiring pattern.

Images