JP2778490B2 - Resin-coated circuit and method of manufacturing resin-coated circuit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin-coated circuit coated with a cured product of a moisture-proof insulating resin and a method for producing the resin-coated circuit.

[0002]

2. Description of the Related Art In water-related equipment, various waterproof and moisture-proof measures are taken in its electric circuit. One of them is a resin-coated circuit. For example, as shown in Japanese Utility Model Application Laid-Open No. 61-114876, the entire circuit board on which electronic components are mounted is covered with a moisture-proof insulating resin. That is, as shown in FIG. 7, the charged portions of all the mounted electronic components 101 are covered with the cured product 103 of the moisture-proof insulating resin together with the entire circuit board 102,
Since there is no exposed charged part, it performs excellent moisture-proof and waterproof function.

[0003] The above-mentioned resin-coated circuit is obtained by molding a moisture-proof insulating resin with a mold so that the circuit board 102 is buried. The circuit board 102 is placed in a simple container corresponding to the mold. Fill the container with moisture-proof insulating resin,
There is also a so-called potting type in which the entire container is handled as a resin-coated circuit.

[0004]

In the above-mentioned conventional resin-coated circuit, under the condition that water accumulates on the upper surface of the cured product 103 of the moisture-proof insulating resin, the cured product 103 deteriorates due to the accumulated water, The insulation properties may be gradually reduced, which may affect the circuit function. In the potting type in which the circuit board 102 is sealed in a container, water adhering to the surface of the cured product of the moisture-proof insulating resin is not drained by the container and accumulates. Further, in order to maintain the waterproof and moisture-proof function, the moisture-proof insulating resin needs to have a certain thickness. However, conventionally, the thickness of the moisture-proof insulating resin is uniform over the entire area of the circuit board 102. There is also a problem that a large amount is required and the cost is high.

The present invention has been made to solve the above-mentioned conventional problems, and an object thereof is to provide a resin-coated circuit in which water adhering to the surface of a cured product of a moisture-proof insulating resin does not remain. That is, to obtain a resin-coated circuit that can maintain the moisture-proof and waterproof function with a small amount of moisture-proof insulating resin, and further establish a method of manufacturing a resin-coated circuit that can maintain the moisture-proof and waterproof function with a small amount of moisture-proof insulating resin. It is.

[0006]

In order to achieve the above-mentioned object, the invention according to claim 1 comprises a flat bottom and an open bottom surface of a container.
A circuit board with electronic components mounted on it
In addition to being fixed, the exposed part that is the charged part of each electronic component
The entire circuit board surface together with the lead portion is buried in a cured product of the moisture-proof insulating resin filled in the container and the surface of which is inclined in one direction with a plane , corresponding to the inclined lower end of the surface of the cured product of the container. A means for providing a drainage structure on the side wall is employed.

According to a second aspect of the present invention, an electronic component having a long standing portion of a lead portion, which is a charged portion, is shifted toward one side, and electronic components having a short standing portion of a lead portion are successively shifted toward an opposite side. circuit board mounted with electronic components in an arrangement such as, solid contained in the top mounting side of this circuit board on the bottom surface
Container which is open at the top at a constant to a flat bottom, filling of this container
With a cured product made of cured and moisture-proof insulating resin.
Is the top surface so that the entire circuit board surface is buried together with each lead at a depth corresponding to the vertical dimension of the lead of each electronic component.
The adopted means letting inclined at a plane in one direction.

According to a third aspect of the present invention, an electronic component having a long standing portion of a lead portion, which is a charged portion, is moved to one side on a circuit board, and an electronic component having a short standing portion of a lead portion is placed on a circuit board. Each electronic component is mounted in a position that is sequentially shifted to the side, and the circuit board on which this electronic component is mounted is stored and fixed almost horizontally on the bottom of the container that is flat and open at the top with the mounting side of the electronic component facing up At the same time, a moisture-proof insulating resin is poured into the container, and the container is tilted so that the entire circuit board surface is buried together with each lead at a depth corresponding to the vertical dimension of the lead of each electronic component. A means is employed in which the moisture-proof insulating resin filled and cured as a cured product having a flat upper surface .

According to a fourth aspect of the present invention, an electronic component having a long standing portion of a lead portion, which is a charged portion, is shifted toward one side, and electronic components having a short standing portion of a lead portion are sequentially shifted toward an opposite side. circuit board mounted with electronic components in an arrangement such as, moisture-proof upper surface to bury the lead portions in the thickness corresponding to the trailing dimension of the lead portion of the electronic parts as well as covers the entire circuit board surface is inclined at a planar from sexual insulating resin
Adopting means comprising a cured product obtained.

[0010]

According to the first aspect of the present invention, the surface of the cured product of the moisture-proof insulating resin is inclined in one direction.
Water adhering to the surface of the cured product flows down along the gradient, and is drained to the outside from a drainage structure provided on the side wall of the container corresponding to the lower end of the slope.

According to the second aspect of the present invention, the leads of each electronic component are buried together with the circuit board with a moisture-proof insulating resin having a thickness corresponding to the length of the vertical dimension of the leads of the electronic components. The amount of the moisture-proof insulating resin can be reduced, and the surface of the cured product of the moisture-proof insulating resin is inclined, so that moisture hardly remains on the surface.

According to the third aspect of the present invention, the amount of the moisture-proof insulating resin used is small, and a resin-coated circuit in which the surface of the cured product of the moisture-proof insulating resin is inclined can be easily manufactured.

In the above-mentioned means, the leads of each electronic component are buried together with the circuit board with a moisture-proof insulating resin having a thickness corresponding to the length of the vertical dimension of the leads of the electronic components, so that the leads are covered. The amount of the moisture-proof insulating resin may be small, and since the surface of the cured product of the moisture-proof insulating resin is inclined, the water is drained without remaining on the surface.

[0014]

An embodiment of the present invention will be described below with reference to the drawings. Embodiment 1 FIG. FIG. 1 is a plan view before filling a resin-coated circuit according to a first embodiment of the present invention, FIG. 2 is a longitudinal sectional side view after the filling, and FIG. 3 is an enlarged view of a main part. The resin-coated circuit shown in each of these figures is composed of a flat-bottomed, shallow-bottom container 1 with a flat bottom and an open top, a circuit board 3 on which various electronic components 2 are mounted, and a cured product 4 of a moisture-proof insulating resin. It is configured. A mounting structure 5 for mounting to a device is formed on a part of the side wall of the shallow container 1, and one of the long side walls has a cut-out window as a drainage structure at the upper edge thereof. 6 are formed.

Circuit board 3 on which various electronic components 2 are mounted
Is lifted up by a boss 7 provided in the same shape on the bottom surface of the shallow container 1 substantially horizontally on the bottom surface of the shallow container 1, and is stored and fixed. The cured product 4 is obtained by curing a moisture-proof insulating resin such as a urethane resin, and the entire surface of the circuit board 3 housed and fixed in the shallow-bottomed container 1 is exposed leads that are charged portions of the electronic components 2. It is covered with the part 8 in a buried state. As shown in FIG. 2, the upper surface, which is the filling surface of the cured product 4, is inclined with a plane in one direction, and the lower edges of several cut windows 6 of the shallow container 1 are located at positions corresponding to the inclined lower ends. Are facing each other. The inclined upper end side of the upper surface of the cured product 4 is located substantially at the upper end of one long side wall of the shallow container 1.

The resin-coated circuit having the above-mentioned structure is mounted on the apparatus substantially horizontally using the mounting structure 5 of the shallow container 1, and is put into a functional state. If devices that are deeply concerned with water, such as hand dryers and dishwashers, are to be installed,
Water may drop or adhere to the surface of the cured product 4. In such a case, since the surface of the cured product 4 is inclined in one direction in this resin-coated circuit, water on the surface flows down along the gradient, and drains to the outside through the slit 6 at a position corresponding to the lower end of the inclination. And does not remain on the cured product 4. That is, the deterioration of the moisture-proof insulating resin due to the residual water is prevented, the stable moisture-proof waterproof function is maintained for a long time, and the circuit function is also maintained. The cut window 6 has a drainage structure, and may be a through hole or a slit.

As shown in FIG. 4, the cured product 4 is a
Is filled with a moisture-proof insulating resin 9, and is molded by placing the shallow container 1 on an inclined curing shelf 10 or the like and curing the resin, but it is easy to move from filling to a curing place. In other words, the filling is performed with the shallow container 1 in a substantially horizontal position, but the filling amount is not fully filled because the filling amount is finally inclined.
It is convenient whether performed manually or by an automatic machine.

Embodiment 2 FIG. In the second embodiment, the arrangement of the electronic component 2 on the circuit board 3 of the first embodiment is devised, and is basically the same as that of the first embodiment. Therefore, this embodiment will be described with reference to FIGS. 1, 2 and 4 respectively.

The circuit board 3 is designed so that the electronic components 2 having a long vertical dimension of the lead portion 8 can be mounted on one side, and the electronic components 2 having a short vertical dimension of the lead portion 8 can be sequentially mounted on the opposite side. Each electronic component 2 is mounted in such an arrangement. The circuit board 3 is housed and fixed on the bottom surface of the shallow container 1 with the mounting side up as in the case of the first embodiment. As in the first embodiment, the cured product 4 itself has a top surface inclined in one direction with a plane, but the cured product 4 made of the moisture-proof insulating resin of the second embodiment has a vertical dimension of the lead portion 8 of each electronic component 2. The upper surface also has a flat surface in one direction so that the entire surface of the circuit board 3 including each lead portion 8 is buried at a depth corresponding to
It is hardened inclined me. Other configurations are basically the same as those of the first embodiment, and a description thereof will be omitted.

The feature of this resin-coated circuit is that the amount of moisture-proof insulating resin 9 to be filled in the shallow container 1 can be reduced without impairing the moisture-proof insulating function. As a result, the surface of the cured product 4, which is the filling surface, is inclined to prevent water from remaining. That is, as shown in FIG. 5, electronic components having different heights of the lead portions are randomly mounted, and all exposed portions of the lead portions, which are the charged portions, are buried with the moisture-proof insulating resin. It is necessary to fill the depth of FIG. 5A with the moisture-proof insulating resin 9 so that the filling surface in which the highest lead portion is buried is formed. The filling amount at this time corresponds to the hatched portion in FIG. On the other hand, in the case of the second embodiment, the electronic components 2 are arranged in accordance with the length of the vertical dimension of the lead portion 8, and the cured product has a depth that is inclined according to the length of the lead portion 8. 4, the filling surface of the moisture-proof insulating resin 9 has a depth of B in FIG. 5, and finally the upper surface is inclined as shown in C of FIG. 5. The filling amount at this time corresponds to the dot pattern portion in FIG. 5, and is significantly smaller than the hatched portion. The other functions are the same as those of the first embodiment, and the description thereof will be omitted.

This resin-coated circuit is basically similar to that of the first embodiment.
Can be manufactured in a manner similar to that of That is, the electronic components 2 having the long vertical dimension of the lead portion 8 are shifted to one side on the circuit board 3 and the electronic components 2 having the short vertical dimension of the lead portion 8 are sequentially shifted to the opposite side to mount the electronic components 2 respectively. Then, the circuit board 3 on which the electronic component 2 is mounted is attached to the electronic component 2.
4 is stored and fixed substantially horizontally on the bottom surface of the shallow container 1 with its mounting side facing up, and a predetermined amount of moisture-proof insulating resin 9 is poured into the shallow container 1 as shown in FIG. What is necessary is just to put on the curing shelf 10 etc. which can adjust a degree of inclination, and to cure and harden it in the state which had a predetermined inclination. Of course, the inclination during curing needs to be maintained such that the entire circuit board 3 including each lead 8 is buried at a depth corresponding to the standing dimension of the lead 8 of each electronic component 2.

Embodiment 3 FIG. As described above, the first and second embodiments are of a so-called potting type in which the circuit board 3 is sealed in the shallow container 1, whereas this embodiment shows a resin-coated circuit having no container. It is. The configuration is the same as that of the second embodiment except for the configuration regarding the presence or absence of the container, but the features of the second embodiment will be described with reference to FIG. 2 according to the first embodiment.

In the resin-coated circuit of the third embodiment, the shallow vessel 1 shown in the second embodiment is used as
It is configured to be used only for molding. Therefore, as shown in FIG. 6, the form of application to the device is composed of the cured product 4 and the circuit board 3 embedded therein, and the shallow container 1 is not provided. Other than this, the manufacturing method and the function are the same as those of the second embodiment, so that the description thereof will be omitted.

[0024]

As is apparent from the above description of the embodiment, according to the first aspect of the present invention, since the surface of the cured product of the moisture-proof insulating resin is inclined in one direction, it adheres to the surface of the cured product. The water that has flowed down along the gradient is drained to the outside from the drainage structure provided on the side wall of the container corresponding to the lower end of the slope, and deterioration of the cured product due to water is avoided, and the circuit function is stable for a long time Not only the entire electronic component, but also
The buried part is buried, so a small amount of moisture-proof insulating resin
The moisture-proof and waterproof function can be maintained and the cost can be reduced.

According to the second aspect of the present invention, the lead portions of the electronic components are buried together with the circuit board with the moisture-proof insulating resin having a thickness corresponding to the length of the vertical dimension of the lead portions of the electronic components. With the moisture-proof insulating resin, the moisture-proof and waterproof function can be maintained and the cost can be reduced. In addition, since the surface of the cured product is inclined, moisture hardly remains on the surface, and deterioration of the cured product due to water can be prevented.

According to the third aspect of the present invention, a low-cost resin-coated circuit in which the amount of the moisture-proof insulating resin used is small and the surface of the cured product of the moisture-proof insulating resin is inclined can be easily manufactured.

According to the fourth aspect of the present invention, the lead portions of each electronic component are buried together with the circuit board with the cured product of the moisture-proof insulating resin having a thickness corresponding to the length of the vertical dimension of the lead portion of the electronic component. The amount of the moisture-proof insulating resin to be coated is small, and the surface of the cured product by the moisture-proof insulating resin is inclined, so that the cured product is prevented from being deteriorated by water,
Circuit function is stable for a long time.

[Brief description of the drawings]

FIG. 1 is a plan view of a resin-coated circuit as one embodiment of the present invention before filling.

FIG. 2 is a longitudinal sectional side view after filling of the resin-coated circuit of FIG. 1;

FIG. 3 is an enlarged view showing a part of a shallow container of the resin-coated circuit of FIG. 1;

FIG. 4 is an explanatory diagram showing a manufacturing process of the resin-coated circuit according to the embodiment of the present invention.

FIG. 5 is an explanatory diagram illustrating functions of a resin-coated circuit according to a second embodiment of the present invention.

FIG. 6 is a sectional view showing a resin-coated circuit according to a third embodiment of the present invention.

FIG. 7 is a cross-sectional view of a conventional resin-coated circuit.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Shallow bottom container 2 Electronic component 3 Circuit board 4 Cured material 6 Cut window 8 Lead part 9 Moisture-proof insulating resin

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H05K 5/00

Claims (4)

(57) [Claims] 1. A circuit board having electronic components mounted on a bottom surface of an open container having a flat bottom and an upper part, is stored and fixed with its mounting side facing upward, and an exposed lead portion as a charged portion of each of the electronic components is provided. The entire surface of the circuit board is buried in a cured product of the moisture-proof insulating resin filled in the container and the surface of which is inclined in one direction with a flat surface, and the side wall corresponding to the inclined lower end of the surface of the cured product of the container. A resin-coated circuit characterized by having a drainage structure. 2. A circuit board on which each electronic component is mounted in such an arrangement that electronic components having a long vertical dimension of a lead portion as a charged portion are shifted toward one side, and electronic components having a short vertical dimension of a lead portion are sequentially shifted toward an opposite side. A flat-bottomed, open-topped container for holding and fixing the circuit board on the bottom surface with the mounting side up, a cured product of a moisture-proof insulating resin filled and cured in the container, and the cured product is each of the electronic components described above. A resin-coated circuit characterized in that an upper surface is inclined with a plane in one direction so that the entire surface of a circuit board is buried together with each lead at a depth corresponding to a standing dimension of a lead of a component. 3. An electronic component having a long standing portion of a lead portion, which is a charged portion, is shifted to one side on a circuit board, and electronic components having a short standing portion of a lead portion are sequentially shifted to the opposite side. The electronic component is mounted, and the circuit board on which the electronic component is mounted is placed and fixed in a substantially horizontal position on the bottom surface of an open container having a flat bottom with the electronic component mounting side facing upward, and a moisture-proof insulating resin is provided in the container. the pouring, on the moisture-proof insulation resin filled in an inclined the container as a whole above the circuit board surface with its respective lead portions in a depth corresponding to the falling dimension of the said lead part of the electronic components are embedded
A method for producing a resin-coated circuit, characterized in that the surface is cured as a cured product having a flat surface . 4. A circuit board on which electronic components having a long standing dimension of a lead portion which is a charged portion are mounted on one side, and electronic components having a short standing dimension of a lead portion are successively shifted on the opposite side. , Covering the entire surface of the circuit board and having a thickness corresponding to the vertical dimension of the lead of each of the electronic components.
A resin-coated circuit made of a cured product made of a moisture-proof insulating resin whose upper surface burying each lead portion is inclined with a plane .