JPH0241877Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] In this invention, a board on which electronic components, etc. are mounted is fitted into one of the open ends, the inside of the case is filled with sealing resin, and the other end is fitted. The present invention relates to an electronic device case for configuring an electronic device, with a lid disposed at an open end.

[Prior Art] FIG. 3 shows the appearance of a conventional electronic device of this type. In the figure, an electronic device 1 has a rectangular cylindrical case 2 made of insulating resin that is open at both upper and lower ends in this figure, and electronic components, etc. are mounted on the lower open end of this rectangular cylindrical case 2. A substrate 4 is disposed, and a lid 3 provided with terminals 4' is disposed at the upper open end of the rectangular cylindrical case 2 after filling the inside of the case with a sealing resin. ing.

Further, case-side mounting holes 5 for screwing to an external member or the like are formed in the lower left and right outer sides of the rectangular cylindrical case 2 in the figure.

As shown in the sectional view of FIG. 4, a bulge 6 is formed around the case-side mounting hole 5 and projects downward. A stepped portion 7 is formed along the inner periphery of the rectangular cylindrical case 2 so as to be substantially flush with the lower end of the bulged portion 6, and the substrate 4 is fitted into this stepped portion 7. There is.

The above substrate 4 may have any structure, such as one in which a predetermined conductive pattern 8 is formed on an insulating plate, or a three-layer structure in which a conductive pattern 8 is formed on a metal plate through an insulating layer. .

Then, when the above board 4 is fitted into the stepped portion 7 of the square tubular case 2, the upper surface of the board 4 as shown in the figure and the lower end surface 6a of the bulging portion 6 of the square tubular case 2 are in contact with each other. The structure is such that the hole 4a and the case-side mounting hole 5 of the rectangular cylindrical case 2 communicate with each other.

In the above configuration, after the substrate 4 is fitted into the stepped portion 7 of the square tubular case 2, the square tubular case 2
By filling the required amount of sealing resin from the other open end of the case, the fluid sealing resin flows into the gap between the rectangular cylindrical case 2 and the substrate 4, and the sealing resin hardens. It serves as an adhesive and fixes the rectangular cylindrical case 2 and the substrate 4.

By the way, due to the accuracy of the machining dimensions of the rectangular cylindrical case 2 and the substrate 4, the rectangular cylindrical case 2 and
There are cases where the gap between the substrate 4 fitted into the stepped portion 7 becomes larger than a specified value, and in that case, the sealing resin to be filled may leak out through the gap.

The outflow of the resin is particularly related to the size of the gap, but the length of the gap, that is, the leakage length, is also significantly related to the amount of resin outflow.

These relationships will be explained in more detail with reference to FIG.

In FIG. 4, the length of the contact part with the substrate 4 fitted into the stepped part 7 is calculated in a vertical section as a
+b.

When we examine the dimensions of a and b above for products actually used, we find that a=0.5mm, b=
Since it is 1.5mm, a+b=2.0mm.
Furthermore, the dimension of the contact area between the outer periphery of the board-side mounting hole 4a of the board 4 and the bulging part 6 is c, and this dimension c is c=0.5 mm in the actual product, so a+b>
c, that is, the leakage length, is shorter at the contact area between the outer periphery of the board-side mounting hole 4a of the board 4 and the bulge 6, so the filled resin mainly flows out from this part.

In order to prevent the filled sealing resin from flowing out as described above, it is sufficient to increase the dimension c, but this can be done by reducing the size of the board-side mounting hole 4a provided in the board 4, or On the other hand, there are two methods of increasing the outer diameter of the bulging portion 6.

However, in order to reliably screw the assembled electronic device to an external member, the board-side mounting hole 4a cannot be made extremely small.

On the other hand, if the outer diameter of the bulging portion 6 on the side of the rectangular cylindrical case 2 is made too large, the conductive pattern 8 formed on the substrate 4 will have to be moved toward the center of the substrate 4.

However, miniaturization of this type of electronic equipment has become the most important issue due to various demands, and the formation position of the conductive pattern 8 has already been designed to be most suitable for miniaturization. It is difficult to move the position of the conductive pattern 8 further inward.

[Problems that the invention attempts to solve] In conventional cases for electronic devices, the rectangular cylindrical case 2
Since the substrate 4 fitted into the rectangular cylindrical case 2 is constructed as described above, the rectangular tube can be removed from the gap between the bulge 6 formed in the rectangular cylindrical case 2 and the contact portion of the substrate 4. There have been problems in that the sealing resin filled inside the case 2 may leak out to the outside, resulting in product defects.

[Purpose of the invention] This invention was made in order to solve the above-mentioned problems, and the sealing resin filled inside the case of the electronic device is leaked from the contact area between the rectangular cylindrical case and the board. The purpose of the present invention is to provide a case for electronic equipment that does not leak outside and does not cause product defects.

[Means for Solving the Problems] The electronic device case according to this invention does not form a gap between the bulge formed in the rectangular cylindrical case and the contact portion with the substrate, and maintains the close contact between the portion. In order to improve this, a tapered part is formed on the outer periphery of the distal end of the bulging part, and this tapered part is fitted into the mounting hole on the board side.

[Function] In the electronic device case of this invention, the tapered part formed at the tip of the bulging part of the rectangular cylindrical case fits into the mounting hole on the board side, so no gap is formed between the contact parts. Therefore, the sealing resin filled inside the case will not leak out to the outside, and product defects will be eliminated.

[Example] An example of this invention will be described below with reference to FIGS. 1 and 2.

In this invention, similarly to the conventional example, mounting holes 5 on the case side for screwing to external members etc. are provided at the lower left and right outer sides of the rectangular cylindrical case 6 which is open at both the upper and lower ends.
A bulge 6 is formed around the mounting hole 5, the lower end of which abuts against the periphery of the board-side mounting hole 4a of the board 4.

In this invention, a tapered portion 60 is formed on the outer periphery of the distal end of the bulged portion 6.

A step portion 7 having dimensions a and b similar to the conventional one is formed along the side wall continuous with the bulge portion 6, that is, along the inner periphery of the open end of the rectangular cylindrical case 6. The structure is such that the substrate 4 is fitted into the housing.

In this case, the tapered part 60 formed on the outer periphery of the tip of the bulged part 6 enters the board-side mounting hole 4a of the board 4, and the outer periphery of the tapered part 60 and the board-side mounting hole 4a
Since the opening edge 4b of the opening 4b is crimped, no gap is formed between them.

In addition, the mouth edge 4b of the board side mounting hole 4a also has a
A chamfer that matches the taper of the tapered portion 60 may be applied.

With the above configuration, when the prismatic cylindrical case 2 is filled with sealing resin, the prismatic cylindrical case 2
A gap is not formed at the contact portion between the cylindrical case 2 and the substrate 1, so that the sealing resin is not leaked out of the rectangular cylindrical case 2, and product defects are not caused.

Since the dimensions a, b, and c of the contact portions are the same as those of the conventional structure, there is no adverse effect on the formation position of the conductive pattern 8 on the substrate 4.

[Effects of the invention] As described above, according to this invention, a tapered part is formed on the outer periphery of the tip of the bulging part of the rectangular cylindrical case, and this tapered part is configured to fit into the mounting hole on the board side. Therefore, there is no gap formed between these contact areas, preventing the sealing resin filled inside the rectangular cylindrical case from flowing out, effectively suppressing product defects, and reducing the effective area of the conductive pattern on the board. It has excellent effects such as not causing any reduction in size.

[Brief explanation of the drawing]

FIG. 1 is a partial sectional view of an electronic device case showing an embodiment of the invention, FIG. 2 is a partially cutaway sectional view of the electronic device case, and FIG. 3 is a conventional electronic device case. FIG. 4 is a partially cutaway sectional view of the conventional electronic device case described above. 1...Electronic equipment, 2...Square cylindrical case, 3...
Lid body, 4... Board, 4a... Board side mounting hole, 4b
... Mouth edge, 5 ... Case side mounting hole, 6 ... Swelling portion, 7 ... Step portion, 8 ... Conductive pattern, 60 ...
...Tapered part.

Claims (1)

[Scope of utility model registration request] A case-side mounting hole to an external member formed on the lower left and right outer sides of a rectangular cylindrical case with both upper and lower ends open, and a board-side mounting hole formed around this case-side mounting hole, and whose bottom end is a board-side mounting hole on the board. a bulge that abuts the periphery of the case, a stepped portion formed along the inner periphery of the open end of the rectangular cylindrical case where the bulged portion is located, and a board for mounting electronic components that is fitted into the stepped portion. and filling a sealing resin into the rectangular cylindrical case by bringing the bulging part around the case-side mounting hole into contact with the periphery of the board-side mounting hole of the board fitted into the stepped part. In an electronic device case for manufacturing a predetermined electronic device, a tapered portion is formed on the outer periphery of the tip of the bulge formed around the case side mounting hole of the rectangular cylindrical case; A case for an electronic device, characterized in that the cylindrical case is fitted into a mounting hole on the board side of the board to prevent a sealing resin filled in the square tubular case from leaking out.