JPH0533466U - Airtight terminal - Google Patents

Abstract

(57) [Summary] [Object] To provide a reliable and inexpensive hermetic terminal having excellent heat resistance and mechanical strength as compared with a conventional glass-sealed hermetic terminal. [Composition] A metal frame 2 is erected on an insulating material substrate 1 to form an airtight space 3, and a metal lead terminal 4 is sealed on the insulating material substrate 1 so as to penetrate the airtight space and the outside. In the terminal, the insulating material substrate 1 is formed by stacking a plurality of layers having a coefficient of thermal expansion sequentially lower than the bottom surface 11,
3 is an insulating material having the same or similar thermal expansion coefficient as that of the metal frame. As a substrate, a plurality of layers having a coefficient of thermal expansion sequentially higher than that of the uppermost layer are laminated, so that the lowermost layer, which is the bottom of the airtight terminal, is glass having high strength and high softening point. Therefore, as compared with the case where one kind of sealing glass is used as in the related art, there is an advantage that it has good strength. On the other hand, since the uppermost surface is the glass for sealing which has the same or similar coefficient of thermal expansion as the metal frame and the metal lead terminal, it does not affect the sealing strength between the metal frame and the substrate.

Description

[Detailed description of the device]

[0001]

[Technical field of invention]

 The present invention relates to a hermetic terminal, and more particularly to a hermetic terminal having good strength and excellent reliability.

[0002]

[Prior art and problems]

 As shown in FIGS. 5 and 6, the airtight terminal comprises a metal frame 2 erected on a substrate 1 made of an insulating material, and a metal lead terminal 4 in an airtight space 3 formed by the metal frame 2 and an airtight space 3 and the outside. The structure is sealed so that it penetrates.

Such an airtight terminal has circuit parts and the like mounted in the airtight space 3 and is electrically connected to the metal lead terminal 4 described above, and then covered with a metal lid (not shown). The metal frame 2 and the lid are adhered to hermetically seal the circuit parts and the like.

Glass is used as an insulating material forming the airtight terminal shown in FIGS. 5 and 6 as described above. This is because the glass is easily sealed to the metal, and the lead terminals and the metal frame are easily sealed or bonded. However, glass-sealed airtight terminals have problems in mechanical strength and heat resistance, and especially in surface-mounted airtight terminals as described above, external physical stress is directly applied to the glass bottom surface. Therefore, there is a possibility that cracks and eventually package damage may occur.

[0005]

[The purpose of the device]

 The present invention has been made in view of the above points, and provides a reliable and inexpensive airtight terminal that has better heat resistance and mechanical strength than conventional glass-sealed airtight terminals. The purpose is to

[0006]

[Means for Solving the Problems] To achieve the above object, an airtight terminal according to the present invention comprises a metal frame standing on an insulating material substrate to form an airtight space, and a metal lead terminal on the insulating material substrate. In an airtight terminal that is sealed so as to penetrate the airtight space and the outside, the insulating material substrate is formed by stacking a plurality of layers whose thermal expansion coefficients are successively smaller than the bottom surface, and the uppermost layer is the thermal expansion of the metal frame. It is characterized in that the insulating material is the same as or close to the rate.

According to the present invention, since the substrate is formed by laminating a plurality of layers having a coefficient of thermal expansion higher than that of the uppermost layer, the bottom layer of the bottom of the hermetic terminal has a large coefficient of thermal expansion. It is possible to employ so-called glass ceramics to which a large amount of high strength, high softening point ceramic powder or the like is added as a filler. Therefore, compared with the case where one kind of sealing glass is used as in the conventional case, there is an advantage that it has good strength. On the other hand, since the uppermost surface is glass for sealing, which has a coefficient of thermal expansion similar to that of a metal frame, it does not affect the sealing strength between the metal frame and the substrate.

[0008]

【Example】

 FIG. 1 is a sectional view of an embodiment of the airtight terminal of the present invention. As is apparent from this embodiment, the airtight terminal according to the present invention has a metal frame 2 erected on a substrate 1 and a metal structure. The lead terminals 4 are sealed so as to penetrate the inside and outside of the airtight space 3. The metal lead terminal 4 has a crank-shaped cross-section similar to that shown in FIGS. 5 and 6, and is sealed so that the bottom of the airtight terminal (bottom of the substrate) extends and projects vertically to the airtight space 3. Has been done.

In the present invention, as is apparent from FIG. 1, glass is laminated so that the coefficient of thermal expansion gradually decreases from the lowermost layer 11 to the uppermost layer 13. Although one intermediate layer 12 is shown in this embodiment, it may have a plurality of layers or may be omitted.

Since the uppermost layer 13 needs to seal the metal frame 2, it needs to have the same or similar thermal expansion coefficient as the material of the metal frame 2.

In this embodiment, the metal lead terminals 4 are sealed by the uppermost layer 13. That is, when the substrate 1 is manufactured, as shown in FIG. 2a, when the lowermost layer 11 to the intermediate layer 12 and the uppermost layer 13 are laminated, holes 14 are formed at the portions where the respective lead terminals of the glass block are sealed. The holes 14 are provided, and the holes 14 are formed so as to become gradually smaller from the lowermost layer 11 to the uppermost layer 13. Next, when the lead terminal sealing hole 14 is pushed in from the direction of the uppermost layer 13 with the punch 5 or the like, the lead terminal sealing hole 15 whose surface is covered with the uppermost layer 13 is formed as shown in FIG. 2B. ..

As the metal frame 2 and the metal lead terminal 4 as described above, a material generally used for an airtight terminal of this type can be effectively used. For example, Kovar, 42 Arrow, etc. can be used.

Kovar metal as described above (coefficient of thermal expansion 45 × 10^-7/ ° C.) is used, the uppermost layer 13 is made of SiO for sealing Kovar.₂-B₂O₃Al as filler for glass₂O₃, ZrO₂It is possible to use glass to which 0 to 30% by weight of one or more of the above is added. When the filler is not added, the coefficient of thermal expansion is 45 × 10. ^-7 / ° C and similar to Kovar, while the coefficient of thermal expansion tends to increase as the filler is added. If it exceeds 30% by weight, there is a problem with the adhesiveness to the metal frame or the lead terminal or the difference in the coefficient of thermal expansion.

The thermal expansion coefficient is gradually increased by sequentially increasing the amount of the filler added from the uppermost layer 13 to the lowermost layer 11. In this case, it is clear that the difference in the coefficient of thermal expansion between the layers adjacent to each other should preferably be small. The upper limit of the difference is preferably 2 × 10 ⁻⁷ / ° C. or less. Therefore, the difference in the addition amount of the filler in the layers adjacent to each other is preferably 10% by weight or less.

An example of the amount of filler added when SiO ₂ —B ₂ O ₃ based glass is used is shown below.

Composition Example 1 Amount of filler (% by weight) Thermal expansion coefficient (× 10 ⁻⁷ / ° C.) Uppermost layer 0 45 Intermediate layer 10 47 Lowermost layer 20 49

Composition Example 2 Filler amount (% by weight) Thermal expansion coefficient (× 10 ⁻⁷ / ° C.) Top layer 10 47 Intermediate layer 20 49 Bottom layer 30 51

Composition Example 3 Amount of filler (% by weight) Thermal expansion coefficient (× 10 ⁻⁷ / ° C.) Uppermost layer 20 49 Intermediate layer 30 51 Lowermost layer 40 53

The above shows a substrate having a three-layer structure, but in the case of forming a five-layer structure, for example, the layers are formed at 5 wt% intervals from the uppermost layer with an addition amount of 0, 5, 10, 15, 20 wt%. You can also do it.

The amount of the filler (Al ₂ O ₃ ) added to the SiO ₂ —B ₂ O ₃ based glass and the result of the glass load test are shown in FIG. 3, and the result of the drop impact test is shown in FIG.

In the glass load test (bending test), Shimadzu Autograph was used, and the load on which the sample was placed was evaluated.

In the drop impact test, a 0.9 g steel ball was dropped onto a sample from a predetermined height and the height at which the sample broke was measured.

As is clear from FIGS. 3 and 4, the bending strength and the drop impact strength tend to improve as the amount of filler added increases. Therefore, by constructing the substrate as in the present invention, it is possible to provide a glass-sealed hermetic terminal having excellent mechanical properties without impairing the electrical and environmental properties.

[0024]

[Effect of the device]

 According to the present invention, since the substrate is formed by laminating a plurality of layers whose coefficient of thermal expansion is sequentially higher than that of the uppermost layer, the lowermost layer which is the bottom of the hermetic terminal is made of glass having high strength and high softening point. Become. Therefore, as compared with the case where one kind of sealing glass is used as in the related art, there is an advantage that it has good strength. On the other hand, since the uppermost surface is a glass for sealing, which has the same or similar coefficient of thermal expansion as the metal frame and the metal lead terminals, it does not affect the sealing strength between the metal frame and the substrate.

[Brief description of drawings]

FIG. 1 is a sectional view of an embodiment of the airtight terminal of the present invention.

FIG. 2a is a sectional view of a method for forming a lead terminal sealing hole.

FIG. 2b is a sectional view showing the structure of a lead terminal sealing hole.

FIG. 3 is a view showing a result of a bending test.

FIG. 4 is a diagram showing the results of a drop impact test.

FIG. 5 is a perspective view of a conventional airtight terminal.

FIG. 6 is a sectional view of the conventional airtight terminal.

[Explanation of symbols]

 1 Substrate 2 Metal Frame 3 Airtight Space 4 Metal Lead Terminal 11 Bottom Layer 12 Middle Layer 13 Top Layer 15 Lead Terminal Sealing Hole

Claims (2)

[Scope of utility model registration request] 1. An airtight terminal in which a metal frame is erected on an insulating material substrate to form an airtight space, and a metal lead terminal is sealed on the insulating material substrate so as to penetrate the airtight space and the outside, The airtight terminal, wherein the insulating material substrate is formed by laminating a plurality of layers having a coefficient of thermal expansion smaller than that of the bottom surface, and the uppermost layer thereof is an insulating material having a coefficient of thermal expansion that is the same as or close to that of the metal frame. 2. The lead terminal sealing hole of the substrate is formed so as to be bent so that the uppermost layer of the substrate is the surface of the sealing hole, and at least a part of the metal lead terminal is formed on the substrate. The airtight terminal according to claim 1, wherein the airtight terminal is sealed with the uppermost layer.