JPH0357021Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to an improvement in an airtight terminal used in an airtight package that hermetically encapsulates circuit elements and the like.

[Prior art]

The conventional airtight package is as shown in Figure 1.
Lead wire insertion hole 3 drilled in the upper wall 2 of the base 1
An airtight terminal T in which a lead wire 4 is inserted and sealed within the base 1 with a sealing insulating material 5 such as glass or ceramic, and a peripheral wall 6 of this airtight terminal T.
It consists of a cap C which is placed over the outer surface to enclose circuit elements 7 in an airtight space. and,
After the circuit element 7 is connected to one end of the lead wire 4, it is placed in the airtight package by covering it with the cap C and crimping the crimp flange 8 of the cap C and the crimp flange 9 of the base 1 to each other. Enclosed.

When bonding such an airtight terminal T and a cap C, the crimping flange 8 of the cap C and the crimping flange 9 of the base 1 are overlapped and crimped as described above, but in this case, the airtight terminal T Since a considerable amount of pressure is applied to the whole, distortion occurs near the connecting part R between the peripheral wall 6 and the crimping flange 9.
As a result, cracks may occur in the sealing insulating material 5. Moreover, the pressure of this press-contact propagates laterally through the base 1 as shown by arrows A and B, and is transmitted to the portion of the sealing insulating material 5, which may cause a crack.

If such a crack occurs, the airtightness of the airtight terminal will be impaired, so an airtight terminal T as shown in Fig. 2 has been developed.
No. 13116). That is, using a base 1 consisting of an upper wall 2, a peripheral wall 6, and a crimping flange 9 provided on the peripheral edge of the peripheral wall 6, a lead wire insertion hole 3 is formed in the upper wall 2.
At the same time, an insulating flange 10 is formed that hangs down from the periphery of the lead wire insertion hole 3, and the lead wire 4 is inserted into the lead wire insertion hole 3 having the insulating flange 10, and the lead wire is This is an airtight terminal with a wire 4 sealed. In the airtight terminal having such a structure, the force from the crimping flange 9 hardly propagates during crimping, so there is no risk of cracking the sealing insulating material 5, and the back surface of the base 1 is completely covered with the sealing insulating material 5. Since there is no burying, it has the advantage of being lighter than conventional methods.

By the way, as mentioned above, the lead wire 4 is inserted into the lead wire insertion hole 3 as shown in FIGS. 1 and 2,
When sealing with the sealing insulating material 5, the above-mentioned insulating material 5
In this case, it is known that the insulating material 5 forms a bulge 50 along the length of the lead wire 4 due to wetting and diffusion.

In recent years, airtight terminals have been required to be smaller and lighter in response to the demand for smaller electrical equipment, so the circuit element 7 and the insulating material 5 have tended to be closer to each other.
Therefore, if the bulge 50 of the insulating material 5 is large,
A situation may occur in which the lead wire 4 swells up to the vicinity 51 where the circuit element 7 is attached. In such a case, there is a possibility that the circuit element 7 connected to the lead wire 4 may not operate normally. Furthermore, it is desirable to flatten such a bulge 50 since it is a place where cracks are likely to occur during crimping.

[Summary of the idea]

The present invention was developed in view of the current situation, and when sealing the lead wire into the lead wire insertion hole formed in the base, at least on the inner side where the circuit element is connected, the lead wire is attached in the longitudinal direction. Another object of the present invention is to provide an airtight terminal in which the insulating material does not bulge.

In order to achieve such an object, in the airtight terminal of the present invention, a lead wire is inserted into a lead wire insertion hole provided in a base having a predetermined shape, and the airtight terminal is sealed with an insulating material for sealing. An insulating ring having a melting point higher than that of the sealing insulating material is placed around the lead wire on at least the inner surface of the donning insulating material, and the sealing insulating material is melted and solidified to seal the lead wire. This is a characteristic feature.

〔Example〕

Hereinafter, one embodiment of the present invention will be described in detail based on the drawings.

FIG. 3 is a sectional view of an embodiment of the airtight terminal according to the present invention, and in the figure, the same reference numerals as in FIGS. 1 and 2 indicate the same members.

As is clear from FIG. 3, the airtight terminal T ₁ according to one embodiment of the present invention has a base consisting of a peripheral wall 6 vertically erected from the crimp flange 10 and an upper wall 2 extending horizontally from the peripheral wall 6. 1. A lead wire insertion hole 3 is formed in the upper wall 2 of the base 1, and the lead wire insertion hole 3 has an insulating material flange 10 hanging down from its periphery. Each lead wire 4 is inserted through this lead wire insertion hole 3, and
The gap formed by the insulating flange 10 is filled with an insulating material 5, and the lead wire 4 is sealed by melting and solidifying the insulating material 5. In the present invention, an insulating material block as shown in FIG. 5 is prepared. I'll do it. That is,
After placing the ring-shaped high melting point insulating material 12 on the sealing insulating material block 5' which has a hole 11 for inserting the lead wire 4, the insulating material block 5' and the insulating material ring 12 are connected to each other. Insert the lead wire 4. Thereafter, the structure thus constructed is fitted into the lead wire insertion hole 3 formed in the base 1, and the lead wire is inserted at a temperature where the sealing insulating material block 5' melts and the high melting point insulating material ring 12 does not melt. 4 to the base 1.

When the lead wire 4 is sealed in this way, as shown in FIG.
Airtight terminal T ₁ on which the insulating material ring 12 is arranged
is formed. In this case, when the sealing insulating material 5 is in a molten state, the insulating material ring 12 is placed on the molten sealing insulating material without melting, so that its weight causes the sealing insulating material to melt. This prevents the melt from swelling in the longitudinal direction of the lead wire 4 due to wetting and diffusion. Therefore, the sealing insulating material 5 does not swell up to the vicinity 40 of the lead wire 4 where the circuit element 7 is attached, and malfunctions and malfunctions of the circuit element 7 sealed by this airtight terminal can be prevented. At the same time, the possibility of cracks occurring in the insulating material portion can be minimized, improving the reliability of the airtight terminal.

As the sealing insulating material 5 as described above, sealing glass can be used. An example of such sealing glass is borosilicate glass. When such a borosilicate glass is used as a sealing glass, as the insulating material 12 having a higher melting point than the sealing insulating material, Al ₂ O ₃ and further SiO ₂ are added to the borosilicate glass. It can be made into high melting point glass. A preferable composition of such high melting point glass is, for example, 10 to 80% by weight of borosilicate glass, 20 to 80% by weight of Al ₂ O ₃
70% by weight, and a glass ranging from 0 to 70% _SiO2 can be used. If the composition is outside the above-mentioned range, there is a risk that the appearance of the airtight terminal may be impaired or that the working temperature may not be within the preferred temperature range.

In addition to the aforementioned Al ₂ O ₃ and SiO ₂ , it is also possible to add one or more types of ZrO ₂ , TiO _{2 ,} etc. to such high melting point glass in order to improve wettability with the sealing glass. be.

Using borosilicate glass as the sealing insulating material 5,
When an airtight terminal according to the present invention was manufactured using an insulating glass containing 50% by weight of borate silicate glass, 25% by weight of Al ₂ O ₃ and 25% by weight of SiO ₂ as the high melting point insulating material 12, the lead wire 4 was sealed. It was possible to manufacture an airtight terminal with a good appearance without causing a bulge 50 of the insulating material 5 at the attachment part.

In the above embodiment, the example of the hermetic terminal shown in FIG. 2 has been described, but it is clear that the present invention can be applied to the hermetic terminal shown in FIG. 1 without any problems.

[Effect of the invention] As explained above, according to the airtight terminal according to the invention, the lead wire is inserted into the lead wire insertion hole provided in the base of a predetermined shape, and the airtight terminal is sealed with an insulating material for sealing. , an insulating material having a melting point higher than that of the sealing insulating material is laid on at least the inner side surface of the sealing insulating material, the sealing insulating material is melted and solidified, and the lead wire is sealed. At least on the inner side where the circuit elements are connected, there is an advantage that the insulating material does not bulge along the longitudinal direction of the lead wire. Therefore, depending on the airtight terminal, there will be no malfunction or oscillation failure of the enclosed circuit elements, and the reliability of the airtight terminal will be improved. is significantly reduced, which has the advantage of improving manufacturing yield and reducing costs.

[Brief explanation of drawings]

Fig. 1 is a sectional view of an airtight package of a circuit element packaged using a conventional airtight terminal, Fig. 2 is a sectional view of another conventional airtight terminal, and Fig. 3 is an airtight package of an embodiment of the present invention. FIG. 4 is a cross-sectional view of the terminal, and FIG. 5 is a front view of an airtight terminal according to an embodiment of the present invention.
The figure is a perspective view of an insulating material block used in the embodiment according to the present invention. DESCRIPTION OF SYMBOLS 1...Base, 2...Base upper wall, 3...Lead wire insertion hole, 4...Lead wire, 5...Insulating material for sealing, 6...Peripheral wall, 7...Circuit element, 12...High melting point Insulating material.

Claims (1)

[Scope of utility model registration request] In an airtight terminal in which a lead wire is inserted into a lead wire insertion hole provided in a base having a predetermined shape and sealed with a sealing insulating material, at least the inner side surface of the sealing insulating material has a height higher than that of the sealing insulating material. An airtight terminal characterized in that an insulating ring having a melting point is placed around a lead wire, and the sealing insulating material is melted and solidified to seal the lead wire.