JPS6012291Y2 - Sealing structure - Google Patents

Description

[Detailed description of the invention] This invention relates to a sealed structure in which lead wires are led out from a metal case through a bushing, and the inside of the case is sealed with a filler such as resin, which improves moisture resistance. The main purpose is to

For example, electrical components such as automobile igniters that are installed in places subject to a lot of vibration are formed of sealed structures as shown in FIGS. 1 and 2.

1 and 2, 1 is a case made of metal such as aluminum, 2 is a substrate made of ceramic or the like fixed on the bottom surface 1a of case 1, and 3 is a cutout provided on side wall 1b of case 1. A rubber bushing 5 fitted into the notch 4 is a plurality of lead wires led out from inside the case 1 via the bushing 3.

Electronic components 6 such as ICs, transistors, and resistors are wired and fixed on the substrate 2, and furthermore, terminals 7 are formed protruding from predetermined locations on the substrate 2, and the lead wires 5 are connected to the protruding tips of the terminals 7. The ends are soldered.

Further, 8 is a buffer material such as a silicone resin, and 9 is a filler material with excellent sealing properties such as an epoxy resin.
, 9 are sequentially filled into the case to airtightly seal the inside of the case.

Further, 10 is a socket that supports the plurality of lead wires 5 so that their ends are aligned.

The silicone resin 8 is poured into the bottom of the case 1 and solidified to the extent that it sufficiently covers the board 2 and electronic components 6, and its buffering effect absorbs external shocks and protects the electronic components 6 and their soldered locations. protection and improved impact resistance.

However, the silicone resin 8 has poor adhesion to the metal case 1, and simply filling it inside the case will deteriorate the moisture resistance inside the case. The case is filled with an epoxy resin 9 of good quality, and this epoxy resin 9 is used to improve the moisture resistance inside the case.

By the way, the silicone resin 8 is inserted into the notch 4 of the case side wall 1b.
The case is filled to a sufficiently distant and low position, and the epoxy resin 9 is filled on top of the case.

However, when the case 1 is filled with the silicone resin 8, its periphery creeps up along the inner surface of the case 1 as shown in FIG. 3, and remains firmly attached to the inner surface of the case 1.

Therefore, the adhesive area (adhesion height) between the inner surface of the case below the notch 4 and the epoxy resin 9 becomes small due to the rising portion 8' of the silicone resin 8. Moisture may enter and the moisture resistance may deteriorate.

In view of the above-mentioned drawbacks, the present invention has been improved and eliminated.The following describes the case where the present invention is applied to the above-mentioned electrical components.
This will be explained with reference to FIGS. 4 to 6.

4 and 5, the same reference numerals as in FIG. 1 indicate the same contents as in FIG. 1.

A feature of the present invention is that the protrusion 12 is integrally formed on the bottom 11a of the case 11.

This protrusion 12 is located on the bottom surface 11a of the case 11 at a predetermined distance 1 from the side wall 11b into which the bushing 3 is fitted.
It protrudes upward, and both ends are attached to separate side walls 11cwlf.
d.

That is, the bottom part of the case 11 is divided into two spaces by the protrusion 12, and the protrusion 12 and the three side walls 11ce
A substrate on which electronic components 6 are attached is fixed on the bottom part A surrounded by lldw lle, and a cushioning resin, such as silicone resin 8, is poured onto this substrate 2 to a height slightly lower than the protrusion 12 and hardened, and then , the case 11 is filled with a filler having excellent sealing properties, such as an epoxy resin 9, and then cured.

According to the above configuration, the silicone resin 8 is attached to one bottom surface portion A.
The projection 12 and each side wall 11b, llc,
The epoxy resin 9 does not flow onto the bottom portion B surrounded by 11d, and only the epoxy resin 9 is filled onto this bottom portion B.

Moreover, even if the silicone resin 8 climbs up the protrusion 12, the protrusion 12
Moreover, even if the silicone resin 8 exceeds the protrusion 12, the amount is small and there is no problem as it will not further climb onto the side wall 11b.

In the case where the bushing 3 is arranged on the side wall of the case, the linear distance from the bushing 3 to the board 2 is short, which poses a problem in terms of moisture resistance, but since the protruding wall 12 extends from the bottom of the case 11, Since the distance is sufficiently long and the epoxy resin 9 adheres to the inner surface of the side wall 11b, the bottom portion B, and one side of the protrusion 12, the adhesive area of the epoxy resin 9 to the case 11 increases significantly, improving moisture resistance. do.

In the above configuration, the case 11 is filled with the silicone resin 8 and the epoxy resin 9, but the filling material is not limited to this, and other side walls or the like may be filled.

Furthermore, the present invention is not limited to sealing structures for parts such as automobile igniters, but can be applied to all sealing structures where moisture resistance is an issue.

As explained above, in the present invention, a protrusion is formed on the bottom of the case along the side wall of the case into which the bushing is fitted.
The adhesive area between the filler and the case increases, improving sealing performance, improving moisture resistance, and extending the life of the product.

[Brief explanation of drawings]

Figure 1 is a side cross-sectional view of a component having a sealing structure, which is the premise of the present invention, Figure 2 is a plan view of Figure 1, Figure 3 is an enlarged view of the main part of Figure 1, and Figure 4 is the main part of the main part. FIG. 5 is a plan view of FIG. 4, and FIG. 6 is an enlarged view of the main part of FIG. 4. 3...Bushing, 5...Lead wire,
8...Buffer material, 9...Filling material,
11...Case, 11a...Bottom, l
lb...Side wall, 12...Protrusion.

Claims (1)

[Scope of utility model registration request] A lead wire is led out through a bushing fitted to a side wall of a box-shaped case, a board on which electronic components are wired and fixed is placed on the bottom of the case, and the board is covered with a first resin, The first resin layer is filled with a second resin to fix the bushing, and is characterized in that a protrusion is formed along the side wall of the case, into which the bushing is fitted, at a predetermined interval and extends from the bottom of the case. A sealed structure.