JPH05152779A - Circuit board - Google Patents

Abstract

PURPOSE:To provide a dew condensation preventing circuit board which does not require any dew condensation preventing measure and is excellent in maintainability. CONSTITUTION:This circuit board 1 is constituted in such a way that an electric resistor 10 which generates heat when it is energized is printed on the board 1 so that the board 1 can be maintained at a temperature higher than the dew- point temperature of the board 1 by the heat generated from the resistor 10. Therefore, the circuit board does not require any dew condensation preventing measure and becomes excellent in maintainability.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circuit board for preventing dew condensation.

[0002]

2. Description of the Related Art FIG. 4 is a perspective view showing an outline of the entire structure of a refrigerator, FIG. 7 is a partial sectional view showing a state in which an example 3 of a conventional circuit board is arranged in a refrigerator, and FIG. FIG. 3 is a partial cross-sectional view showing a state in which the example 3 ′ of FIG. Generally, as shown in FIG. 4, the door portion 2 of the refrigerator body 2 is
At 0, a display unit 21 and an operation unit 22 are provided. The circuit board 3 to which the electronic components 5 for controlling the display unit 21 and the operation unit 22 are connected is arranged in the arrangement unit 23 provided in the door portion 20 as shown in FIG. 7. However,
Since the arrangement portion 23 is formed on the urethane foam heat insulating layer 24, the thickness of the urethane heat insulating layer 24 at that portion is thin, and dew condensation easily occurs on the circuit board 3. Therefore, conventionally, in order to prevent the occurrence of dew condensation on the circuit board 3, the heater 4 is embedded in the urethane foam heat insulating layer 24 in the vicinity of the arrangement portion 23, and the heat radiation of the heater 4 causes dew condensation on the circuit board 3. It was designed to prevent you from doing so. Also,
As shown in FIG. 8, a metal oxide resistor 9 is formed on the surface of the circuit board 3 '.
It has also been known to insert a resistor (hereinafter abbreviated as “resistor”) to prevent dew condensation similar to the above by radiating heat from the resistor 9.

[0003]

However, in the case of the conventional circuit board 3 shown in FIG. 7 described above, it is necessary to take a dew condensation prevention measure such as burying the heater 4 in the urethane foam heat insulating layer 24, and the burying thereof. This causes inconvenience such as troublesome work. In addition, since the heater 4 is embedded in the urethane foam heat insulating layer 24 in this manner, if the heater 4 is defective or malfunctions, the entire door portion 20 must be discarded and replaced. Become. On the other hand, in the case of the circuit board 3'shown in FIG. 8, since the circuit board 3'can be independently replaced, the above inconvenience is eliminated. However, since the resistor 9 attached to the surface of the circuit board 3'is a large resistance such as a metal oxide resistor, the installation space for electronic parts may be narrowed, and the rear surface of the circuit board (pattern surface) that requires a temperature rise. ) In some cases, good heat conduction to the vicinity was not achieved. The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a circuit board for preventing dew condensation that does not require any other dew condensation prevention measures and is excellent in maintainability.

[0004]

In order to solve the above-mentioned problems, a circuit board of the present invention is a circuit board mounted in a place where the ambient temperature is relatively low. Is printed, and the circuit board is kept above the dew point temperature by the heat generation of the electric resistor. Furthermore, the circuit board is mounted on the pattern surface of the circuit board in a circuit board mounted in a place where the ambient temperature is relatively low, and a chip resistor that generates heat when energized is appropriately arranged.

[0005]

According to the circuit board of the present invention, by energizing the electric resistor printed on the circuit board, the circuit board can be kept at the dew condensation temperature or higher and the dew condensation can be prevented. Further, the circuit board can be kept above the dew point temperature and the occurrence of dew condensation can be prevented also by mounting the chip resistors that are mounted on the pattern surface of the circuit board and generate heat when energized. As a result, it is possible to obtain a circuit board for preventing dew condensation that is excellent in maintainability without the need to take other dew condensation prevention measures.

[0006]

Embodiments of the present invention will be described below with reference to the accompanying drawings for the understanding of the present invention. The following embodiments are examples of embodying the present invention and are not of the nature to limit the technical scope of the present invention. 1 is a perspective view showing an outline of an overall configuration of a circuit board 1 according to a first embodiment of the present invention, FIG. 2 is an exploded perspective view showing a state in which the circuit board 1 is arranged in a refrigerator, and FIG. 3 is a circuit board 1 4 is a partial cross-sectional view showing a state in which the refrigerator is arranged, FIG. 4 is a perspective view showing the outline of the entire structure of the refrigerator (shared with the conventional example), and FIG. 5 is a circuit board 1 ′ according to a second embodiment of the present invention. FIG. 6 is a perspective view showing the outline of the overall structure of FIG. 6, and FIG. As shown in FIG. 1, the circuit board 1 according to the first embodiment of the present invention is one in which an electric resistor 10 which generates heat when energized is printed on the circuit board 1. A wiring circuit (not shown) for connecting various electronic components 5 is formed on the circuit board 1 by a copper foil pattern. The electric resistor 10 can be printed on the substrate surface (partial insertion surface) opposite to the wiring circuit. The position where the electric resistor 10 is printed is a position where it does not interfere with various electronic components 5 connected to this wiring circuit,
It can be printed anywhere on the substrate. However, in order to prevent the generation of dew condensation due to the heat generation of the electric resistor 10, it is preferable to print the entire surface of the substrate instead of printing it locally. The circuit board 1 thus configured is
As shown in FIGS. 2 to 4, it is attached to the door portion 20 of the refrigerator main body 2, for example. That is, the circuit board 1 to which the electronic component 5 is connected, the display section 21 and the operation section 22 are connected, and the circuit board 1, the display section 21 and the operation section 22 are arranged in the arrangement section 23 provided in the door section 20. It is constructed by incorporating. In this case, since the urethane foam insulation layer 24 is thinner than the other portions in the arrangement portion 23, dew condensation is likely to occur on the circuit board 1, but
By energizing the electric resistor 10, the circuit board 1 can be maintained at the dew point temperature or higher, and the occurrence of dew condensation can be prevented.

Next, a circuit board 1'according to a second embodiment of the present invention will be described. As shown in FIG. 5, in the circuit board 1 ′, the chip resistor 8 is mounted at a required position on the pattern surface of the circuit board 1 ′ to form a heating element portion. Although the pattern connecting the chip resistors 8 is shown in the figure,
The other circuit patterns are omitted. This circuit board 1 '
In the same manner as in the first embodiment, for example, is incorporated in the disposing portion 23 provided in the door portion 20 of the refrigerator main body 2 in FIG. In this case, too, the placement unit 23 causes the chip resistor 8
By energizing the circuit board 1 ', the circuit board 1'can be maintained at a dew point temperature or higher, and dew condensation can be prevented. As described above, according to the first and second embodiments of the present invention, the construction work can be easily performed and the cost can be reduced without providing the arrangement portion 23 with the special dew condensation preventing structure. It will be possible. Even if the electric resistor 10 of the circuit board 1 or the chip resistor 8 of the circuit board 1'causes defective conduction or failure to cause dew condensation on the circuit board 1 or 1 ', FIG. The circuit board 1 or 1'without replacing the entire door portion 20 as in the conventional example shown in FIG.
Can be easily repaired by replacing. Further, since neither circuit board 1 nor 1'is provided with the large-sized resistor 9 on the surface of the circuit board as in the conventional example shown in FIG. 8, there is no fear of narrowing the installation space for electronic parts, and the circuit board 1 ，
Condensation can be efficiently prevented by directly raising the temperature on the back surface of 1 '. Further, a temperature control element (for example, PTC) is inserted in a power supply circuit (not shown) of the electric resistor 10 of the circuit board 1 or the chip resistor 8 of the circuit board 1 ', and the power supply is turned on when there is no need of heat retention. By cutting off, power consumption can be reduced and energy saving measures can be taken. In this embodiment, the circuit boards 1 and 1'connected to the display portion 21 and the operation portion 22 of the door portion 20 are shown, but the present invention is not limited to this door portion 20, and dew condensation may occur. It can also be used for various circuit boards arranged at easy positions. In addition to the refrigerator, it can be used for various circuit boards such as air conditioners and electric appliances for cold regions.

[0008]

As described above, since the circuit board of the present invention can prevent the occurrence of dew condensation, it is not necessary to take a dew condensation prevention measure such as a heater in the portion where the circuit board is arranged, and it is possible to reduce Condensation can be easily prevented at a cost. In addition, even if the dew condensation prevention function fails, it can be easily repaired by simply replacing the circuit board, which is excellent in maintainability. In addition, since a large resistance unlike the conventional example is not provided on the front surface of the circuit board, there is no fear of narrowing the installation space for electronic components, and the back surface of the circuit board can be directly heated to effectively prevent dew condensation. it can. Further, by inserting a temperature control element into the power circuit of the electric resistor or the chip resistor of the circuit board,
When it is not necessary to keep warm, the power consumption can be reduced by turning off the power supply and energy saving measures can be taken.

[Brief description of drawings]

FIG. 1 is a perspective view showing an outline of an overall configuration of a circuit board 1 according to a first embodiment of the present invention.

FIG. 2 is an exploded perspective view showing a state in which the circuit board 1 is placed in a refrigerator.

FIG. 3 is a partial cross-sectional view showing a state in which the circuit board 1 is arranged in a refrigerator.

FIG. 4 is a perspective view showing the outline of the entire configuration of the refrigerator (shared with the conventional example).

FIG. 5 is a perspective view showing the outline of the overall configuration of a circuit board 1 ′ according to a second embodiment of the present invention.

FIG. 6 is a partial cross-sectional view showing a state in which the circuit board 1 ′ is arranged in a refrigerator.

FIG. 7 is a partial cross-sectional view showing a state where a third example of a conventional circuit board is arranged in a refrigerator.

FIG. 8 is a partial cross-sectional view showing a state in which another example 3 ′ of the conventional circuit board is arranged in a refrigerator.

[Explanation of symbols]

 1 ... Circuit board 10 ... Electric resistor

Claims (2)

[Claims] 1. A circuit board mounted in a place where the ambient temperature is relatively low, wherein an electric resistor that generates heat upon being energized is printed on the circuit board, and the heat generated by the electric resistor causes the circuit board to have a dew point temperature or higher. A circuit board characterized by being kept. 2. A circuit board to be mounted in a place having a relatively low ambient temperature, wherein a chip resistor which is mounted on the pattern surface of the circuit board and generates heat when energized is appropriately arranged. ..