JPS601894A - Electronic part - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in the structure of an electronic component in which internal elements such as a piezoelectric resonator and a thermistor are housed in a case and sealed with resin.

DESCRIPTION OF PRIOR ART FIGS. 1 and 2 are a perspective view and a sectional view taken along the line I-1 showing an example of a conventional electronic component, and this electronic component 1 is manufactured in the following order. That is, after housing an internal element 3 such as a piezoelectric element and terminals 4 and 5 in a case 2 consisting of an inner case 2a and an outer case 2b, the case opening 2c is sealed with molten a resin 6. However, there are problems in that during heat sealing, the pressure inside the case 2 increases and a via hole may be formed in the resin 6, and that it is difficult to obtain a complete IeV sealed state.

For this reason, conventionally, the case 2 has been provided with n through holes 7 in order to prevent fluctuations in the pressure inside the case. Note that after the through hole 7 is sealed with the resin 6, it is sealed with a room temperature curing resin 9.

The shape of this n through hole 7 is shown in FIGS. 3 and 4.
As shown in the partially cutaway perspective view, a case having a recess 8 having a relatively large diameter on the outer surface of the case is used. The recess 8 facilitates resin injection into the n-through hole 7 having a relatively small diameter.

However, in the example shown in FIG. 3, as shown in a partial cross-sectional view in FIG. .

On the other hand, in the example shown in FIG. 4, in order to prevent the sealing resin 9 from flowing into the case 2, a protrusion 10 is provided to increase the length of the through hole 7. It is virtually impossible to form such a protrusion 10 in a small electronic component, and even if such a protrusion 10 is formed, the sealing resin 9 still cannot be avoided.

Although through-holes having shapes other than those shown in FIGS. 3 and 4 have been proposed, in either case it is not possible to control the flow of the sealing resin into the inside of the case.

OBJECT OF THE INVENTION Therefore, an object of the present invention is to reliably prevent the sealing resin from flowing into the above-mentioned n-holes.
Our objective is to provide electronic components with excellent sealing properties.

Structure of the Invention Simply put, the present invention is an electronic component characterized in that a recess having a relatively larger diameter than the through hole is formed on the inner and outer sides of the case of the through hole. .

Other features of the invention will become clear from the following description of embodiments with reference to the drawings.

DESCRIPTION OF EMBODIMENTS FIG. 6 is a longitudinal sectional view showing an embodiment of the present invention.
FIG. 7 also shows a plan view. The feature of this embodiment is that, as is clear from the enlarged portion of FIG. 6 indicated by a circle, a recess 11. 12 is formed.

Other patterns are the same as those of the conventional electronic component shown in FIGS. 1 and 2, so their explanation will be omitted.

In this embodiment, the recess 11. has a larger diameter than the different through hole 7.
12 is formed, and when the n through hole 7 is sealed with resin, the sealing tree 1119 can easily enter the through hole 7 because the outer surface side recess 11 exists.
When the internal pressure is higher than the external pressure, it is possible to reliably prevent the sealing resin 9 from blowing out to the outer surface of the case. Furthermore, since the recess 12 is present on the inner surface of the case, when the pressure inside the case 2 is lower than that outside, it is possible to reliably prevent the sealing resin 9 from entering the inner surface of the case 2. This was confirmed by the following experiment. In other words, when the n through hole 7 is sealed with resin, when the sealing resin 9 is relatively soft, if the pressure inside the outer case 2b is high, the surface tension of the sealing resin 9 will cause damage as shown in FIG. The sealing resin 9 swelled on the side of the recess 11, and when the pressure inside the outer case 2b was low, the sealing resin 9 swelled on the side of the fourth part 12 due to its surface tension.

From these facts, since the n-through hole 7 of this embodiment has the recesses 11 and 12 on the inner and outer sides of the case, the force based on pressure changes inside and outside the case 2 is absorbed by the seals stored in the recesses 11 and 12. It will be understood that it can be absorbed by the sealing resin 9, and therefore it is possible to completely prevent the sealing resin 9 from entering the electronic component or spewing out to the outside.

In the embodiments shown in FIGS. 6 and 7, the diameters of the recesses 11 and 12 provided on the inner and outer surfaces of the case were different, but the diameters of the recesses on the inner and outer surfaces of the case were the same. They may be the same. The four parts 11 and 12 may have enough capacity to store a certain amount of resin for sealing the through hole 1.

Effects of the Invention As described above, according to the present invention, recesses are formed on the inner and outer sides of the case of the N through-hole, and the recesses are filled with sealing resin, so that when sealing the through-hole, It is possible to reliably prevent the sealing resin from entering the inside of the case or spouting out to the outside of the case. Therefore, it is possible to prevent an adverse effect on the internal elements due to the entry of the sealing resin into the inside of the case, and it is also possible to obtain an electronic component with an excellent appearance. Furthermore, since the bonding area between the resin sealing the n-through hole and the case is increased, the sealing performance of the through-hole is improved, and it becomes possible to provide an electronic component with excellent reliability. Furthermore, since there is no need to make the case wall thickness particularly thick at the through-hole portion, it can be applied to extremely small electronic components. In addition, since recesses with relatively large diameters are formed on both sides of the through hole and have a capacity, it is possible to absorb variations in the viscosity of the sealing resin, so the condition of the sealing resin used can be strictly controlled. It has various effects such as no need for control.

It should be pointed out that this invention is generally applicable to all electronic components that require complete sealing.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing an example of a conventional electronic component. , FIG. 2 is a sectional view taken along line 1-1 of the electronic component shown in FIG. FIG. 3 is a partially cutaway perspective view showing an example of the shape of a through hole in a conventional electronic component. FIG. 4 is a partially cutaway perspective view showing another example of the shape of a through hole in a conventional electronic component. FIG. 5 is a partially cutaway sectional view for explaining the flow of the sealing resin into the n through hole shown in FIG. 6th
The figure shows an embodiment of this application (it is a sectional view and corresponds to FIG. 2. FIG. 7 is a plan view of the embodiment shown in FIG. 6. FIG. 9 is a partially cutaway sectional view showing the state of the sealing resin in the F1 through hole of the embodiment shown in FIG. 6, FIG. 8 shows a case where the pressure inside the case is high, and FIG. Indicates when the pressure outside the case is too high. J01...Electronic component, 2...Case, 3...Internal element, 7...N through hole, 9...Resin for sealing the through hole. 71゜12...concavity. (2 idiots) Figure 4 Centroid Figure 5 Figure 6 Figure 8 Center Figure 7

Claims (1)

[Claims] The case includes an internal element and a case with a frontage for accommodating the internal element, the case opening is sealed with resin, and the case has a resin-sealed case opening. In an electronic component in which a through hole is formed in order to prevent fluctuations in the internal pressure of the case, and the through hole is sealed with resin after the case frontage is sealed with resin, the inner side of the case of the through hole and An electronic component characterized in that a recess having a relatively larger diameter than the n-hole is formed on the outer surface of the case.