JPH1117318A - Method and structure for fixing electronic parts - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily and economically fix electronic parts in a earthquake- resistant state by forming annular bodies of a highly viscous curing agent by heaping up the agent around electronic parts on an electronic circuit board and fixing the parts by pouring a low-viscosity fluid curing agent into the insides of the annular bodies. SOLUTION: After a plurality of electronic parts 2 is mounted on an electronic circuit board 1, annular bodies 3 of a high-viscosity curing agent, such as the silicone rubber, etc., having a prescribed height are formed by applying the curing agent in a heaping-up state so as to surround the electronic parts 3 group. Then a low-viscosity curing agent 4, such as the silicone rubber, epoxy resin, etc., is poured into the insides of the annular bodies 3. The curing agent 4 fills up the periphery of each parts 2 and seals and fixes the parts 4 after curing. The thickness of the curing agent 4 is set to such a degree that the parts 2 can be fixed with a sufficiently high earthquake-resisting property. It is possible to prepare the curing agent 4 by mixing an insulator, such as ceramic powder, etc., having high thermal conductivity in a silicon-based resin, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for fixing an electronic component mounted on an electronic circuit board and a structure for fixing the electronic component.

[0002]

2. Description of the Related Art In recent years, various electronic functions have been introduced into automobiles, and accordingly, many electronic circuit boards on which electronic components are mounted are mounted in the automobile. The fixing structure of an electronic component mounted on such an electronic circuit board, unlike a general electric product, requires a high level of vibration resistance against vibrations caused by running of an automobile or the like.

Generally, an electronic component that controls a large amount of electric power has a large shape and a high height, so that sufficient vibration resistance cannot be obtained when the electronic component is simply mounted (connected with solder or the like) on an electronic circuit board. For this reason, as for the fixing structure of these electronic components, as shown in FIG. 4, the entire electronic circuit board 1 housed in the case 11 is sealed in a filler 14 made of a hardening material such as silicone rubber. The structure is taken away.

A case 11 shown in FIG. 4 houses the electronic circuit board 1, and the case 11 itself includes a bottom plate 12 and a side plate 13, and the side plate 13 has a size enough to accommodate a filler 14 therein. Have a height. When housing the filler 14, the electronic circuit board 1 is placed in the case 11.
And the filler 14 is poured into the case 11, and the entire electronic circuit board 1 including the electronic component 2 is buried in the filler.

[0005]

As shown in the above prior art, in a structure in which the entire electronic circuit board 1 and electronic components 2 housed in a case 11 are buried in a filler, the filler 14 is used. Case 1
Care must be taken when designing 1.

In the method using such a case 11, a case 11 having a size equal to or larger than the size of the electronic circuit board 1 and the electronic components 2 is required. In this case, an installation space for the case 11 mounted on a vehicle is required. , The size of the electronic circuit board 1 accommodated therein is also limited, which causes a problem that the degree of freedom in circuit design is reduced.

Further, since the entire electronic circuit board 1 in the case 11 is buried in the filler, it is difficult to take out the signal line from the connector of the electronic circuit board 1 or the like. is there.

If the electronic component 2 includes, for example, an electrolytic capacitor 2a, the electrolytic capacitor 2a
Is completely buried in the filler, so that the gas generated from the electrolytic capacitor 2a cannot be released, thereby causing a problem that the inside is corroded. As shown in FIG. 5, there is a method of radiating heat of the electronic component 2b that generates heat by using the copper pattern 7 of the electronic circuit board 1. In this case, the electronic component 2b and the copper pattern 7 are usually used. In this case, a structure is used in which a connection is made by using a solder 15, and in this case, a reflow device for heating the connection portion is required, and there is a problem that the work is troublesome.

The present invention has been made in view of the above problems, and a method of fixing an electronic component mounted on an electronic circuit board can be easily and economically performed and has excellent vibration resistance. And an electronic component fixing structure.

[0010]

In order to solve the above-mentioned technical problems, a method for fixing an electronic component according to the present invention, as shown in FIG. 1, uses one or more electronic components mounted on an electronic circuit board. In the fixing method, a high-viscosity hardening material is raised on an electronic circuit board around the one or more electronic components to form an annular body of the hardening material having a predetermined height, and the inside of the annular body of the hardening material is formed. Then, a flowable hardening material having a low viscosity is poured into the space, and the hardening material is filled around the electronic component to fix the electronic component.

[0011] In addition to the above, the method of fixing an electronic component according to the present invention, by changing the viscosity of the high-viscosity hardening material, adjusts the degree of swelling of the hardening material,
The ring of the hardening material is formed at a desired height.

FIG. 1 shows a structure for fixing an electronic component according to the present invention.
As shown in the above, in the fixing structure of one or more electronic components mounted on the electronic circuit board, on the electronic circuit board around the one or more electronic components, a cured material formed by being raised to a predetermined height The structure includes a ring and a hardening material that is poured into the ring of the hardening material and is filled around the one or more electronic components to fix the electronic component.

Further, the fixing structure of the electronic component according to the present invention comprises:
In a fixing structure of an electronic component in which a hardening material is filled around the surface of one or more electronic components mounted on an electronic circuit board to fix the electronic component, a hardening material having high thermal conductivity is used as the hardening material, This is a structure in which heat radiated from the component is conducted to the electronic circuit board via the curing material having high thermal conductivity.

Further, according to the present invention, there is provided an electronic component fixing structure for fixing an electronic component by filling a curing material around the surface of one or more electronic components mounted on an electronic circuit board. A structure in which a necessary electronic component among the electronic components is filled with the hardening material except for a part of the electronic component itself up and down, and a gas generated from the electronic component is discharged from the removed gap. It is.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a method and structure for fixing an electronic component according to the present invention will be described below in detail with reference to the drawings.

FIG. 1 shows a structure for fixing the electronic component. The electronic circuit board 1 according to this fixing structure includes:
A plurality of electronic components 2 for controlling relatively large power are mounted.

In practice, a high-viscosity hardening material is first used, and it is raised and applied so as to surround the group of electronic components 2 to be fixed, thereby forming an annular body 3 of the hardening material. The ring 3 of the hardening material is formed by a method of forming one that surrounds the whole of the electronic component 2 on the electronic circuit board 1, and also, depending on the height of the electronic component 2, the ring 3 depends on the type of the height. There is a method of providing a plurality of rings 3 of hardening materials having different heights. When a plurality of rings 3 are provided, the structure may be such that a part of one ring 3 and a part of another ring 3 are common. In addition, electronic components and the like that do not need to be fixed
May be removed from the frame. The shape of the ring 3 is not limited to a circular shape, and the shape may be various.

As a method of applying the hardening material, for example, a hardening material is extruded from a predetermined nozzle and applied over the periphery of the electronic circuit board 1. Examples of the high-viscosity curing material include silicone rubber (high-viscosity, non-flowable paste) and epoxy resin (high-viscosity, non-flowable) such as materials having excellent mechanical strength and electrical insulation. Is preferred.

When a hardening material having a high viscosity is applied, the height of the hardening material is appropriately adjusted based on the height of the electronic component 2 group, and is slightly lower than (or equal to or less than) the height of the electronic component 2 group. In general, it is not particularly harmful to make the height higher than the height of the electronic component group).

As a standard for the viscosity of the high-viscosity hardening material, a non-fluid paste-like material that can be formed to a desired height without breaking the raised hardening material is used. In this case, for example, if the viscosity is high, even if the hard material is raised high, it does not collapse, so that the ring 3 of the hardening material having a high wall is formed. , The height that can be maintained is reduced.

From this, by changing the viscosity of the hardening material, a ring 3 having a height corresponding to the viscosity is formed. Therefore, the height of the ring 3 is changed by changing the viscosity of the hardening material. adjust. Further, in this case, if the viscosity of the hardening material is constant, the ring 3 of the hardening material is eventually formed at a relatively uniform height even if there is some difference in the height of the hardening material. .

Of course, there is also a method of applying while adjusting the height of the swelling without changing the viscosity of the hardening material. In this case, however, in order to spread the hardening material to a uniform height, the adjustment of the application is complicated. Becomes In addition, strip-shaped plate members are arranged in a ring on the inner side and the outer side at predetermined intervals along a portion of the electronic circuit board 1 where the ring body 3 is formed, and a hardening material is poured between the two plate materials. There is also a method of removing the above plate material depending on the degree of the above. According to this method, an annular body of the hardening material is formed at an accurate position. However, it takes time to dispose and remove the plate material, and it is necessary to wait for the hardening material between the plate materials to harden.

After the ring 3 of the hardening material is formed on the electronic circuit board 1, a hardening material 4 having a low viscosity is poured into the ring 3. In this case, in particular, when a quick-drying hardening material such as silicone rubber is used for forming the ring 3, the hardening material 4 can be poured into the ring 3 with little time after application. Examples of the low-viscosity curing material 4 include silicone rubber (low-viscosity fluidity),
A material having excellent electrical insulation and mechanical strength such as an epoxy resin (low-viscosity fluid) is suitable. Therefore, as a standard for the viscosity of the low-viscosity hardening material, a material having a fluidity enough to fill the surroundings of the electronic components over the details thereof is used.

The poured hardening material 4 is filled around the electronic component 2 group, and after the hardening material 4 is hardened, the individual electronic components 2 are sealed and fixed. The thickness of the hardening material 4 is such that the tip of the electronic component 2 is exposed to the outside for the electronic component 2 having a predetermined height. The point is that the thickness of the electronic component 2 hardened by the hardening material 4 against vibration during driving of the automobile or the like may be sufficient to provide sufficient vibration resistance. Needless to say, the entirety of the necessary electronic component 2 may be covered with the hardening material 4 for waterproofness or the like.

In this embodiment, in particular,
In the case where the electronic component 2 is an electrolytic capacitor 2a, consideration has been given to sufficiently release the gas in the electrolytic capacitor 2a. That is, as shown in FIG. 2, a hardening material is filled in the side wall of the electrolytic capacitor 2 a except that a part thereof is vertically removed, and the removed part is used as a gas vent hole 5.

In this case, when the hardening material 4 is poured into the ring body 3, an appropriate material (for example, clay) is attached to the wall surface of the above-mentioned part of the electrolytic capacitor 2a in advance, and this portion is formed. After swelling up and down, and after the hardening material 4 is hardened, this material is removed, so that the gas vent holes 5 are formed.
To form By forming the gas vent hole 5 in this manner, gas leaking from the lower part of the electrolytic capacitor 2a can be appropriately vented.

Another embodiment according to the present invention will be described. As the electronic component 2 mounted on the electronic circuit board 1 and controlling relatively large power, an electronic component 2b that generates a large amount of heat may be used. Such an electronic component 2
For the electronic circuit board 1 on which the b is mounted, a hardening material having a high thermal conductivity (for example, a hardening material such as a silicone-based or epoxy-based resin, and an insulating material having a high thermal conductivity such as a ceramic powder) are used. Mixture).

FIG. 3 shows a state in which a hardening material 6 having a high thermal conductivity is poured into the ring body 3 and is filled around the electronic component 2b. In this case, the hardening material 6 is filled in the gap between the electronic component 2b and the electronic circuit board 1. Therefore, if a copper pattern 7 is provided below the electronic component 2b as a part of a circuit on the substrate, the electronic component 1
The heat radiated by b is quickly transmitted to the copper pattern 7 through the hardening material 6 having high thermal conductivity, and further transmitted to the electronic circuit board 1 and radiated to the outside, thereby being generated from the electronic component 2b. Dissipation of heat is performed effectively.

Although the above embodiment has been described with reference to the case where electronic components for controlling relatively high power are mounted on the electronic circuit board 1, it is needless to say that the electronic components for controlling low power are mounted. Even so, it is possible to adopt a similar embodiment, and similar effects can be expected.

Therefore, according to the above embodiment, the ring 3 of the hardening material is formed on the electronic circuit board 1 and the hardening material 4 is poured into the inside thereof. Fixing can be performed easily and economically. Further, since a case for housing the electronic circuit board 1 is not required, the electronic circuit board 1 filled with the hardening material 4 is configured to be compact as a whole, so that no space is required even when the electronic circuit board 1 is mounted on a vehicle. This is convenient, and the restriction on the size of the electronic circuit board 1 is relaxed as compared with the method using the case, so that the degree of freedom in designing the electronic circuit is also increased.

Further, since the height of the wall of the ring 3 of the hardening material is changed depending on the degree of the viscosity of the hardening material, the ring 3 having a desired height can be easily formed. Also,
As a result, the hardening material 4 in the ring body 3 can be formed to have an appropriate thickness, so that the electronic component 2 can be appropriately and satisfactorily fixed according to its height and the like. Vibration resistance can be obtained.

Further, by providing a plurality of rings having different heights, it is possible to form the hardened material 4 having an appropriate thickness according to the height of the electronic component and in consideration of vibration resistance. Further, since the side end portion or the back surface of the electronic circuit board 1 is not covered with the hardening material, it is easy to take out the signal line from the terminal of the electronic circuit board 1 such as a connector.

[0033]

As described above, according to the method for fixing an electronic component according to the present invention, a hardened material having a high viscosity is raised on an electronic circuit board around the electronic component to obtain a hardened material having a predetermined height. A ring is formed, and a hardening material having low viscosity is poured into the ring of the hardening material to fix the electronic component. There is an effect that a method for fixing components can be realized.

In addition, since a method of adjusting the degree of swelling of the hardening material by changing the viscosity of the hardening material having a high viscosity is adopted, it is possible to easily form the ring of the hardening material to a desired height. There is an effect that can be.

According to the electronic component fixing structure of the present invention, the ring of the hardened material formed by being raised to a predetermined height on the electronic circuit board around the electronic component, and the ring of the hardened material are formed. Since it adopts a structure composed of a hardening material that is poured inside and filled around the electronic components to fix the electronic components, there is no need to house the electronic circuit board in a case or the like,
There is an effect that a structure for fixing an electronic component having excellent vibration resistance can be easily and economically realized.

Further, according to the electronic component fixing structure of the present invention, a hardening material having a high thermal conductivity is used as a hardening material, and heat radiated from the electronic component is passed through the hardening material having a high thermal conductivity to the electronic circuit board. The structure is such that the heat generated from the electronic component is effectively dissipated.

Further, according to the electronic component fixing structure of the present invention, since a gap is formed by filling the hardening material around the electronic component itself except for a part thereof up and down to form a gap, so that the electronic component is vented. This is effective in preventing corrosion and the like in such electronic components.

[Brief description of the drawings]

FIG. 1 is a diagram showing a fixing structure of an electronic component according to an embodiment of the present invention.

FIG. 2 is a view showing a gas vent hole formed in a part of an electronic component according to the embodiment of the present invention, and FIG.
(B) is a plan view, respectively.

FIG. 3 is a view showing a state in which a hardening material having high thermal conductivity is filled around an electronic component according to the embodiment of the present invention.

FIG. 4 is a view showing a fixing structure of an electronic component according to a conventional technique.

FIG. 5 is a diagram showing a heat dissipation structure in an electronic component that generates heat according to the related art.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 electronic circuit board 2 electronic component 3 ring 4 hardening material 5 gap (gas vent hole) 6 hardening material with high thermal conductivity

Claims (5)

[Claims] 1. A method of fixing one or a plurality of electronic components mounted on an electronic circuit board, wherein a high-viscosity hardening material is raised on an electronic circuit board around the one or more electronic components to a predetermined height. Forming an annular body of the hardening material, pouring a hardening material having a low viscosity into the inside of the annular body of the hardening material, filling the hardening material around the electronic component and fixing the electronic component. A method for fixing an electronic component. 2. The method according to claim 1, wherein the degree of swelling of the hardening material is adjusted by changing the viscosity of the hardening material having a high viscosity to form a ring of the hardening material at a desired height. Item 7. The method for fixing an electronic component according to Item 1. 3. A fixing structure for one or a plurality of electronic components mounted on an electronic circuit board, comprising: a cured material formed to be raised to a predetermined height on an electronic circuit board around the one or more electronic components. A ring body, and a hardening material that is poured into the ring of the hardening material, and is filled around the one or more electronic components to fix the electronic component. Fixed structure. 4. An electronic component fixing structure for fixing an electronic component by filling the surface of one or more electronic components mounted on an electronic circuit board with a hardening material, wherein the hardening material has a high thermal conductivity. Wherein the heat radiated from the electronic component is conducted to the electronic circuit board through the hardening material having a high thermal conductivity. 5. An electronic component fixing structure for fixing an electronic component by filling a hardening material around a surface of one or more electronic components mounted on an electronic circuit board, wherein a necessary electronic component among the electronic components is provided. A fixing structure for an electronic component, characterized in that a periphery of the electronic component itself is partially and vertically removed and the hardening material is filled, and a gas generated from the electronic component is released from the removed gap.