JP4552354B2 - Circuit equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a circuit device in which an internal space of a case body is filled with resin to improve vibration resistance.
[0002]
[Prior art]
Conventionally, as shown in FIG. 4, there is a circuit device 100 in which a case body 103 on which a circuit board 102 on which a circuit element 101 is mounted is filled is filled with a resin material 104 in order to improve vibration resistance and waterproofness. . When the circuit element 101 mounted on the circuit board 102 is a heat generating heat generating element 101 such as a transistor or a power MOS (electrolytic effect transistor), the inside of the case body 103 is filled with a resin material having poor heat conductivity. If this is done, the temperature of the heating element 101 may rise above a predetermined temperature, leading to destruction of the heating element itself (thermal destruction phenomenon).
[0003]
Therefore, a filler such as fused silica which is an inorganic piece in the resin material 104 in order to prevent heat from the heat generating element 101 from being thermally conducted to the case body 103 through the resin material and to suppress a temperature rise of the heat generating element 101. 105 is mixed. By mixing the filler 105, the filler 105 functions as a heat conduction medium, and the heat conductivity from the heating element 101 to the case body 103 is improved. In addition, the case body 103 is formed from a resin material, and the case body 103 can be reduced in weight and molded to improve its workability.
[0004]
[Problems to be solved by the invention]
However, the circuit device 100 in which the filler is mixed in the conventional resin material 104 has the following problems. That is, as shown in FIG. 4, in the circuit device 100 using the large-sized inorganic piece (2 mm to 3 mm diameter size), the filler 105 is filled in the internal space of the case body in which the circuit board 102 is installed. Yes. The resin material 104 is injected into the gap between the circuit board 102 and the filler 105. However, when the filler 105 is filled in advance, the filler 105 is made of a hard material, so that the heating element 101 or the like that is a circuit element mounted on the circuit board 102 is damaged, and a defect as the circuit device 100 is generated. is there.
[0005]
Further, as described above, if the filler is made of a finer-sized inorganic piece so as not to damage the heating element 101 and the like by the hard filler 105 having a large size, damage to the heating element 101 and the like can be prevented. However, if this small size filler is mixed in the resin material 104 in such an amount that the thermal conductivity can be expected, the viscosity of the resin material of the mixture of the small size filler and the resin material 104 is increased, so that the filling workability is deteriorated. To do.
[0006]
As described above, the method of mixing the filler into the resin material 104 is problematic because the filler damages the heat generating element 101 and the like and it is difficult to fill the filler. Moreover, in order to mix any size filler, the process of mixing this filler is required, which increases the cost of the circuit device 100, which is a problem.
[0007]
In view of the above-described points, an object of the present invention is to provide a circuit device that can prevent a filler as a heat conduction medium from being mixed in a resin material filled between a case body and a heating element, and can suppress a temperature rise of the heating element. It is to provide.
[0008]
[Means for Solving the Problems]
In order to solve the above-described problem, according to the circuit device according to claim 1 of the present invention, the heat dissipation is formed at least in part of the case body facing the heating element and integrated with the case body. A member is provided , and the heat dissipation member is embedded in the first resin material constituting the case body .
[0009]
Thereby, the heat generated from the heating element is transferred to the case body via the second resin material filled in the internal space of the case body. At this time, the second resin material to be filled is not filled with filler and is inferior in thermal conductivity, but is disposed at least in a part of the case body made of the first resin material facing the heating element and the case body. The heat dissipating member integrally formed absorbs heat from the filled second resin material and dissipates the absorbed heat to the outside periphery of the case body. Therefore, a filler is not mixed in the second resin material filled between the case body and the heating element, and the temperature rise of the heating element can be suppressed. Moreover, by burying the heat radiating member in the first resin material constituting the case body, the heat radiating member is not peeled off from the case body, and the positional relationship between the two can be stabilized.
[0010]
According to claim 2 of this invention, a heat radiating member is arrange | positioned in the said part of case body used as a substantially parallel arrangement relationship with a circuit board, It is characterized by the above-mentioned.
[0011]
Thereby, the distance between the heat dissipating member arranged in a substantially parallel arrangement relationship with the circuit board and the heating element mounted on the circuit board can be reduced. Therefore, the heat radiating member arranged at the above-described position can efficiently absorb the heat generated from the heat generating element and suppress the temperature rise of the heat generating element.
[0014]
According to claim 3 of the present invention, the heat dissipation member is made of a metal material or a ceramic material.
[0015]
Thus, by comprising a heat radiating member from a metal material or a ceramic material, the heat capacity to be absorbed can be increased, and a heat radiating member having a stable shape can be integrated with the case body.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a circuit device according to an embodiment of the present invention will be described in detail with reference to the drawings.
In addition, the circuit device described below can prevent the filler from being mixed into the resin material filled between the case body and the heating element in the internal combustion engine ignition device as the circuit device, and can suppress the temperature rise of the heating element. Regarding technology.
[0017]
FIG. 1 is a cross-sectional view showing a main part of a circuit device according to an embodiment of the present invention.
FIG. 2 is a top view of the circuit device shown in FIG. A circuit device (hereinafter referred to as an internal combustion engine ignition device) 1 shown in FIG. 1 has an opening 3 in a case body 2 made of a first resin material, and heat is generated in the internal space of the case body 2 from the opening 3. A circuit board 5 on which an electric circuit such as a circuit element including the element 4 is mounted is installed. And the case body 2 is filled with a resin material 6 as a second resin material to constitute an igniter that controls transmission of a primary current to an ignition coil (not shown).
[0018]
The resin material 6 filled in the internal space of the case body 2 is made of a soft resin such as urethane resin for potting, and is filled so as to be in contact with an electric circuit such as the heating element 4 and the inner wall of the case body 2. By filling the resin material 6, the circuit board 5 is molded to improve the vibration resistance and waterproofness of the circuit board 5. On the other hand, the filled resin material 6 forms a medium for transmitting heat generated from the heating element 4 to the case body 2, and the resin material 6 is filled with a filler as a heat conduction medium. In comparison, the thermal conductivity from the heating element 4 to the case body 2 is inferior.
[0019]
Therefore, a heat radiating member 7 is provided which is disposed on a part of the case body 2 made of a resin material and is formed integrally with the case body 2. That is, the heat dissipating member 7 is made of a metal material or a ceramic material, and is embedded in a resin material that constitutes the case body 2 in a substantially parallel arrangement relationship with the circuit board 5. In the present embodiment, the circuit board 5 is embedded in the side surface of the case body 2 on the side where the heating element 4 is mounted. As shown in FIG. 2, the heat radiating member 7 is disposed in a shape that covers at least a region where the heat generating element 4 of the circuit board 5 is mounted as a region where the heat radiating member 7 is embedded in the case body 2.
[0020]
As described above, if the heat dissipating member 7 is arranged substantially parallel to the circuit board 5, the heat dissipating member 7 and the heat generating element 4 mounted on the circuit board 5 are arranged close to each other and are generated from the heat generating element 4. The heat is absorbed efficiently to prevent the heating element 4 from rising in temperature. Further, by embedding the heat radiating member 7 in the resin material constituting the case body 2, the heat radiating member 7 is prevented from being peeled off from the case body 2, and the positional relationship between the two and 7 is stabilized.
[0021]
The internal combustion engine ignition device 1 in which the heat dissipating member 7 is disposed and configured in a part of the case body 2 absorbs heat from the resin material 6 filled with the heat dissipating member 7, and the absorbed heat is absorbed by the case body 2. To dissipate heat to the outside. Therefore, a filler is not mixed in the resin material 6 filled between the case body 2 and the heating element 4, and the temperature rise of the heating element 4 can be suppressed.
[0022]
In FIG. 1, reference numeral 8 denotes a connector 9 and a connector 9 and a circuit board for connecting to an engine control device (not shown) after the resin material 6 which is a soft resin is filled in the internal space of the case body 2. 5 is a hard resin such as an epoxy resin molded for the purpose of fixing and protecting the periphery of the terminal 10 connected to the terminal 5.
[0023]
(Modification)
FIG. 3 shows a circuit device (ignition device for an internal combustion engine) 1A which is a modification of the present invention. FIG. 3 is a cross-sectional view showing a main part of a circuit device which is a modification of the present invention. Components that are substantially the same as those of the embodiment shown in FIGS. 1 and 2 are denoted by the same reference numerals, and description thereof is omitted. 3 differs from the internal combustion engine ignition device 1 shown in FIGS. 1 and 2 in that a heat radiating member 7a is provided in another part of the case body in addition to the heat radiating member 7. FIG.
[0024]
As shown in FIG. 3, the heat radiating member 7 a is embedded in the first resin material constituting the case body 2 that is in a substantially parallel arrangement relationship with the circuit board 5. And this heat radiating member 7a was embed | buried inside the case body 2 side surface of the back side in which the heat generating element 4 in the circuit board 5 is mounted. In addition, as a region where the heat radiating member 7 a is embedded in the case body 2, at least a region on the back side where the heating element 4 of the circuit board 5 is mounted is disposed.
[0025]
In carrying out the present invention, the heat dissipating members 7 and 7a are configured so as to be in a substantially parallel arrangement relationship with the circuit board 5. However, the present invention is not limited to this, and the case body 2 is integrated with the case body. If it arrange | positions and it arrange | positions, it can contribute to suppression of the temperature rise of the heat generating element 4 by absorbing the heat from the resin material 6 which is the 2nd resin material.
[0026]
In carrying out the present invention, the heat radiating members 7 and 7a are configured inside the case body 2. However, the present invention is not limited to this, and the heat radiating members 7 and 7a are exposed to the outside of the case body 2. By forming the body 2 and the heat radiation members 7 and 7a so as not to peel off, the positions of the two 2, 7, and 7a may be stabilized.
[0027]
In carrying out the present invention, the heat dissipating members 7 and 7a are made of a metal material or a ceramic material. However, the present invention is not limited to this, and heat generated from the heating element 4 can be absorbed through the resin material 6 and has a shape. The heat dissipating members 7 and 7a are variously selected as long as they are stable members.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing main parts of a circuit device according to an embodiment of the present invention.
2 is a top view of the circuit device shown in FIG. 1. FIG.
FIG. 3 is a cross-sectional view showing a main part of a circuit device which is a modification of the present invention.
FIG. 4 is a cross-sectional view showing a main part of a conventional circuit device.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Circuit apparatus 2 Case body 4 Heating element 5 Circuit board 6 (filled) 2nd resin material

Claims (3)

A circuit device in which a circuit board on which a heating element is mounted is installed in an internal space of a case body made of a first resin material, and a second resin material is filled so as to be in contact with both the case body and the heating element Because
A heat dissipating member disposed at least in part of the case body facing the heat generating element and formed integrally with the case body ;
The circuit device , wherein the heat radiating member is embedded in the first resin material constituting the case body .   The circuit device according to claim 1, wherein the heat dissipating member is disposed in the part of the case body that is disposed in a substantially parallel relationship with the circuit board. The circuit device according to claim 1 , wherein the heat dissipation member is made of a metal material or a ceramic material.

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