JPS59203737A - Glass for sealing metal - Google Patents

Abstract

PURPOSE:To obtain the titled glass capable of providing secure sealing for ''Kovar'' alloy and having superior water resistance consisting primarily of SiO2 and B2O3 with a coefft. of linear expansion and transition temp. close to those of ''Kovar'' alloy. CONSTITUTION:Glass for sealing ''Kovar'' alloy comprising 61.2wt% (shortly described as % hereunder) SiO2, 5.0-7.8% Al2O3, 20.2-22.6% B2O3, 1.0-1.9% Na2O, 1.5-2.5% K2O, 1.0-2.0% Li2O, 0-2.0% BaO, 0-3.8% ZnO, 0.2-1.0% P2P5, 0-0.3% As2O3, and 0-0.3% Sb2O3, and having (44-48)X10<-7>/ deg.C mean coefft. of linear expansion at 30-380 deg.C and 470-480 deg.C transition temp. Since the glass has a coefft. of linear expansion and transition temp. close to those of ''Kovar'' alloy, secure sealing of ''Kovar'' is possible. Moreover, the proportion of B2O3 is reduced while adding P2O5 and increasing the proportion of Al2O3, the water resistance is improved without elevating the transition temp. Since no fluorine-contg. component is contained, liberation of fluorine which is harmful for cathodes of thermionic tube in the state of heat-sealing of the glass is avoided.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an alloy plate of iron, nickel, and cobalt known under the trade name Kovar, which is used for sealing an alloy of similar metals (1) Glass. Regarding the composition of

Generally, in order to obtain a stable sealed body by sealing glass to a copper alloy, the coefficient of linear expansion of the glass must be determined.

It is necessary that the transition temperature matches the linear expansion coefficient and transition temperature of the copper alloy. To this end, it is desirable that the copper alloy sealing glass has an average linear expansion coefficient of 10/°C and a transition temperature of 470°C to 480°C between 30°C and 380°C.

Conventionally, borosilicate glass containing a large amount of boric acid component has been mainly used as this type of glass for sealing Kovar alloy. Among them, 7050 is a borosilicate glass whose linear expansion coefficient and transition temperature are close to those of copper alloys. C4, O.

Glasses called by symbols such as FCN have been used because they can provide a stable sealed body of glass and copper alloy. [Glass referred to by these codes is written by: Materials of Hypercuum Technology
2 volumes of silicate (1&terialsof High
Vacuum Technology Volume2
5ilicates).

Author: Werner Espe
rPublisher: 1”9) Pergamon Press, UK.
Ltd.

0xford ) r Publication year: 1968 In the book,
7050 glass is 8-! ! - Second, C40 glass is 1
6 pieces, FCN glass is 18 pieces! ! - Each S self is listed in the page. ] However, these glasses have the disadvantage of poor water resistance.

Reducing the boric acid component in borosilicate glass, which has a high boric acid content, improves water resistance, but it also makes it difficult to melt the glass.
Also, the transition temperature of the glass is too high. As a countermeasure to this problem, adding a small amount of fluorine to the glass improves the water resistance and meltability of the glass, and lowers the transition temperature. Corning Glass Work of the United States has made use of this fact to improve the properties of glass.
There is glass with the code 7052 manufactured by S, U, S, A, ). However, this 7052 glass has the disadvantage that it releases harmful fluorine compounds during the encapsulation process of the vacuum tube, which reacts with the cathode of the vacuum tube and impairs electron emission from the cathode. [This is explained in the book title: Materials and Techniques for Electron Tubes (
Materials and Techniques
forE]ectron Tubes) rAuthor: Walter H-Kohl
), Publisher: Reinhold Noe, New York, USA
Pricing Corporation (Re1nhold P
Publishing Corporation) r Publication year: 1960, pageo: 563.

] There is also the glass described in US Pat. No. 2,392,314 as a glass with good water resistance other than 7052 glass, but this also contains fluorine and is not preferred for the same reason as the drawback of 7052 glass.

An object of the present invention is to provide a glass that can be safely sealed with a copper alloy.

Another object of the invention is to provide a glass with excellent water resistance.

Still another object of the present invention is to heat-seal glass.
The objective is to provide a glass that releases harmful fluorine to the cathode of a vacuum tube.

The composition of this invention is 1% by weight r 5I0261.2
~65.0, AA2035.0~7.8, B2
0320.2-22.6.

Na2O1,0~1.9, K2O1,5~2.5
, Li2O1, O~2.0゜BaOO~2.0,
ZnOO~3.8, P2O50,2~1.01As
2o30~o, 3,5b2030~0.3 depending on the synthetic composition of each component selected, 30℃~380℃
The average linear expansion coefficient between ℃ is 44~48 x 10-'/℃
, relates to a copper alloy sealing glass characterized by a transition temperature of 470°C to 480°C.

The glass according to the present invention has a coefficient of linear expansion and a transition temperature close to those of a copper alloy, so that when the glass according to the present invention is sealed to a copper alloy, the glass will not be damaged and will be safe. Can be sealed,
Add P2O5 and increase the amount of At2o3 used r B2
By selecting the composition of the glass to reduce the amount of O3 used, the water resistance of the glass is improved without increasing the transition temperature of the glass.Furthermore, since it does not contain fluorine components, when the glass is used as a vacuum tube container, the glass When heat-sealing the glass, harmful fluorine is not emitted to the cathode of the vacuum tube, so the life of the vacuum tube is not impaired, and the disadvantages of this type of conventional glass mentioned earlier are largely eliminated. .

(5) Next, various components constituting the copper alloy sealing glass of the present invention and reasons for limiting the range of properties will be explained.

Moatless Sio2 forms the framework of the glass and is also useful for improving water resistance. However, the content is 65.0 in weight percentage.
If the amount is more than %, the glass is difficult to melt and can be used. On the other hand, if it is less than 612 degrees, the coefficient of linear expansion is too large, the residual stress at the sealing part with the copper alloy becomes too large, and the occurrence of glass cracks increases, which is unsuitable.

A/, 03 is added to suppress devitrification of glass and improve water resistance, but if it exceeds 7.8% by weight, the glass becomes poorly soluble, causing striae and bubbles in the glass. etc. will increase, degrading the quality of the glass, and if it is less than 5.01, the water resistance will deteriorate rapidly, which is not preferable.

B2O5 is an effective component that not only helps glass meltability but also lowers the transition temperature, but at 1% by weight it is 22.6%.
If it exceeds %, the water resistance of the glass will deteriorate.

If it is less than 202%, the transition temperature of the glass will be too high (6) and the occurrence of lath cracks will increase in the sealing area with the copper alloy, which is not appropriate.

Na 2 O is used to improve the meltability of the glass and to increase or decrease the linear expansion coefficient of the glass.

If the weight percentage is more than 1.9 parts, the linear expansion coefficient becomes too large, and if it is less than 1.0 dl, the glass meltability deteriorates rapidly, which is inappropriate.

When used in combination with *Na2O, KO improves the thermal insulation properties of the stain and, like +Na2O, has the effect of improving the meltability of glass and increasing/decreasing the coefficient of linear expansion.20
If you add more than 2.5 yen in weight percentage, the coefficient of linear expansion will be too large! If the amount is less than 1.5 inches, the meltability of the glass will deteriorate, and it is unsuitable as in the case of Na2O.

Li2O increases or decreases the coefficient of linear expansion and significantly improves the melting properties of glass, but if used in large quantities, it deteriorates water resistance, and if more than 2.0% by weight is added, the coefficient of linear expansion becomes too large, and Water resistance also worsens, 1.0%
If it is less than that, the coefficient of linear expansion will be too small and the life will be too long. In any case, if it is outside the specified range, it is inappropriate because it increases the occurrence of lath cracks at the sealing part with the Kovar alloy.

BaO has an effect on the increase/decrease in the linear expansion coefficient of glass.
O, KO+ Li2O is effective in improving the meltability without exerting a significant influence, but if more than 2.0% (2% by weight) is added, the transition temperature becomes too high. However, BaO
Since glass melting is possible even without the addition of ZnO, the limited range is limited to 0.2% and the lower limit is set to 0.ZnO not only improves water resistance but also has the effect of lowering the transition temperature when added in small amounts. However, if more than 38% by weight is added, the transition temperature becomes too high, which is inappropriate. Also ZnO
If the amount added is less than 0.5%, the effect of improving water resistance and lowering the transition temperature will be weakened, but if BaO is not added to the glass component, the transition temperature will be 4 even without adding ZnO.
Temperatures range from 70℃ to 480℃, water resistance is 10m9/
Good glass can be obtained below El.

The lower limit of the limited range was set to 0.

P2O5 has the effect of lowering the transition temperature, but if it is added in an amount greater than 1.0% by weight, the glass tends to devitrify, so it is not suitable for cine. Further, if it is less than 0.2%, the effect of lowering the transition temperature is insufficient.

As　O and 5b203 are for melting glass and removing bubbles.

3 are used to aid in clarification, but the effect is not particularly noticeable even if each is added in a weight percentage of more than 0.3%.

Next, the average linear expansion coefficient of glass between 30℃ and 380℃ is 4
．． 4. Even if it is less than X 10-7/℃, it is also 48
Even if the temperature exceeds 1°C, there is a large difference in linear expansion coefficient from that of the copper alloy, so if the two are sealed together, cracks are likely to occur in the glass.

The average linear expansion coefficient of glass between 30℃ and 380℃ is 44~
When limited within the range of 48 x 10-7/°C.

Even if the transition temperature of the glass is lower than 470°C.

Furthermore, even if the temperature is higher than 480°C, the incidence of lath cracks in the glass and copper alloy sealed body increases. This invention was conceived by integrating the various data mentioned above.

The present invention will be described below with reference to Examples.

To obtain glasses having the compositions shown in Tables 1 to 9.

(9) According to a conventional method, glass raw materials containing the components were prepared so that the weight component ratio of the glass was the numerical value described in the mixing ratio (weight ratio) column of the same table. The value obtained by converting this blending ratio (weight ratio) into a weight percentage is also written in the converted composition (weight percentage) column. Batch prepared according to each composition is heated and melted at 1440°C to 1450°C over 10 hours using a platinum crucible in a small electric melting furnace to form molten glass, and then slowly cooled and subjected to glass testing. I created a piece.

The properties of the glasses thus obtained are shown in the properties column of each table. The coefficient of linear expansion described herein is the average value between 30° C. and 380° C. measured using a standard type thermal dilatometer manufactured by Rigaku Denki Co., Ltd., 8095-TMA. In addition, when measuring the coefficient of linear expansion, when increasing the temperature at the same heating rate, there is a temperature at which expansion begins to increase rapidly. A line close to a straight line of the curve was extended, and the temperature at the intersection of the eight straight lines was defined as the transition temperature. In addition, for each person, the linear expansion coefficient and transition temperature r10) The values below the decimal point in the degree column are reference values that include errors. Furthermore, the water resistance is a value measured in a first-order manner using the quartz glass water resistance testing device shown in FIG. That is, 20 minutes of distilled water 2 was added to flask 1 of the water resistance test device.
Add 0cc and place it on top of electric heater 3. Meanwhile, the glass obtained by melting is crushed.

Using a JIS Z 8801 (1956) sieve, the particle size was adjusted to a particle size between 42 mesh and 28 mesh, and 6 grams to 7 grams of the strain-removed glass sample 4 was precisely weighed using a chemical balance.
A quartz glass pass (51C) case is hung from a key 7 at the bottom of a quartz glass cooler 6 with a platinum wire 8. key 7
are installed at three locations approximately 120° apart. - The bottom 9 of the gasket 5 is made of sintered plate-shaped particles of fused silica with a size of 80 mesh to 65 mesh. As shown in FIG. 1, these are gently placed together with the mating parts 10. The cooler 6 performs cooling by causing cold water to flow into a cooling water outlet 11 and flowing out through a cooling water outlet 12. Turn on electric heater 3 and start heating. When the distilled water 2 begins to boil, water vapor rises rapidly and flows through the hole 1 in the cooler 6.
3 to the cooling section 14.

As a result, the water vapor is cooled and liquefied, passes through the side wall of the cooler 6, passes through the corrugated pipe 15 below the cooler T6, and falls.During this time, the water vapor rising outside the corrugated pipe 15 reheats the water vapor to a temperature close to its boiling point. and drips into the basket 5. The temperature of the electric heater 3 is adjusted so that the glass sample 4 is constantly immersed in high-temperature water and the water does not overflow. After the glass sample 4 is completely immersed in warm water and heating is continued for 3 hours, the shim joint 10 is removed, the glass sample 4 is transferred to a beaker, dried, and then weighed. Subtract the sample weight after boiling from the sample weight before boiling to determine the weight loss due to the water resistance test, and divide this by the sample weight before boiling.

The weight loss calculated in milligrams per gram of the sample is shown in the characteristics column for each person as water resistance. The numerical values listed in this characteristic column are the average values obtained by repeating measurements three times for the same lot. The smaller this value is, the better the water resistance is.

Table 1 shows the case where the proportions of components other than S + 02 are kept almost constant and an arbitrary amount of SiO2 is added.

S i related to the linear expansion coefficient, transition temperature, and water resistance of glass
This shows the influence of O2. Similar experiments were conducted below. For comparative reference, compositions outside the scope of the claims are also marked with an asterisk (*) in the left margin.

When the amount of S102 exceeds 65.0%, the glass becomes difficult to melt, and when it is less than 9.61.2%, the coefficient of linear expansion becomes 48.
It becomes larger than ×10/°C.

Margin below (13) Table 2 shows the case where the proportions of components other than At203 were kept almost constant and an arbitrary amount of At203 was added.

If the amount of At203 exceeds 7.8%, the glass will be difficult to melt, and if it is less than 5.0%, the water resistance will suddenly deteriorate.

Table 3 below shows the case where the proportions of components other than B2O3 were kept almost constant and an arbitrary amount of B2O3 was added.

If the amount of B2O3 exceeds 22.6%, the water resistance of the glass will be poor, and if it is less than 20.2%, the transition temperature of the glass will become higher than 480°C.

, below, margin (17) (18 Table 4 shows the case where the proportions of the components other than Na 20 were kept almost constant and an arbitrary amount of Na 20 was added thereto.

When Na20 exceeds a coefficient of 1.9, the coefficient of linear expansion is 48X1
If the temperature is less than 0-7/°C, it becomes difficult to melt the glass.

Margin below (19) Table 5 shows the case where the proportions of the components other than 20 are kept almost constant and an arbitrary amount of 20 is added.

If the added 2O exceeds 2.5%, the linear expansion coefficient will be 48.
×107°C If the content is less than 1.5%, it will be difficult to melt the glass.

Margin below (22) Table 6 shows the case where the proportions of components other than L120 were kept almost constant and an arbitrary amount of Li2O was added thereto.

When the added Li2O exceeds 2°0%, the linear expansion coefficient increases to 4.
8X10 7℃ It is very thick and its water resistance deteriorates, exceeding 10m9/J. If L120 is less than 1.0%, the coefficient of linear expansion will be smaller than 44 x 10"-7/℃. This is the case when an arbitrary amount of BaO is added to this.Although aO is a component that is effective in improving the melting properties of glass, it is possible to melt glass without adding BaO.
A case in which BaO was not contained was also described as an example.

When the amount of BaO exceeds 20%, the transition temperature increases to 480°C.
It gets really expensive. Even without adding BaO, a glass with characteristics within the claimed range can be obtained, and the water resistance is also good.

Table 8 below shows the case where the proportions of components other than ZnO were kept almost constant and an arbitrary amount of ZnO was added thereto. Even for compositions in which no aO is added, the proportions of components other than r ZnO are kept almost constant, and cases in which an arbitrary amount of ZnO is added are also listed in the lower four rows of the same table.

In glass with BaO added, when the amount of ZnO exceeds 3.8%, the transition temperature becomes higher than 480°C.

If the ratio is less than 1.0, the water resistance will exceed 10 μ/g.

If it is less than 0.5%, the transition temperature will also be higher than 480°C.

However, for composition glasses without BaO addition.

Even if the amount of ZnO added is less than 1.0%, a glass having the characteristics within the claimed range can be obtained, and the water resistance is also good.

The following clue (27) Table 9 shows the case where the proportions of components other than P2O5 were kept almost constant and an arbitrary amount of P2O5 was added thereto.

If the added P2O exceeds 1.0%, the glass tends to devitrify during heat processing, and if it is less than 0.2%, the transition temperature will be 4.
It will be as high as 80 degrees Celsius.

The following margins The glasses of the examples shown in Tables 1 to 9 above were sealed to a blank rod of copper alloy with a diameter of 1 inch, and the residual stress existing in the glass at the sealed portion was measured using a photoelastic device. However, the residual stress was 0.3 kid/ltm2 or less in all cases. Generally, the residual stress in the sealed area between glass and metal is 0.9k.
If it is less than g/mm2, it is safe. Therefore, the copper alloy sealing glass of the present invention can be sealed with a copper alloy sufficiently and safely.

Further, the glass of the present invention has improved water resistance, and its value is 30 to 10.277 g, #. Furthermore, the conventional 7050 glass, C40 glass, and FC mentioned at the beginning
We prototyped a glass with the same composition as N glass.

The water resistance of this prototype glass was measured using the same method as shown in the examples, and the value obtained was 72.4 as shown in Table 10.
~110.2m9/,9. It can therefore be seen that the water resistance of the glass according to the present invention is better than that of the conventional glass.

Margin below (31) Table 10 and more. Since the glass of this invention does not contain fluorine, it does not suffer from the drawbacks caused by fluorine as mentioned at the beginning, which is also a significant effect of this invention.

In the second embodiment below, an example was described in which the glass of the present invention was sealed with a copper alloy.
rnico) + Therlo, o-goo (Rodar) Sealvac
) , = o-K (lt'J+]o K) r Dilver P
It is also effective for sealing with alloys with the trademark name Con), other inorganic materials with almost the same linear expansion coefficient as copper alloys, such as C39) molybdenum, iron-nickel alloys, and other inorganic metals such as lath 1 clad metals. One thing is easy to understand.

[Brief explanation of drawings]

FIG. 1 is a sectional view of an apparatus for measuring water resistance in accordance with the present invention. The symbols used in the drawings are as follows. 1... flask, 2... distilled water, 3... electric heater,
4...Glass sample, 5...Basket, 6...Cooler. 7...Key, 8...Platinum wire, 9...Bottom of the basket. 10...Slot joint part, 11...Cooling water inlet, 12.
...Cooling water outlet, 13...hole, 14...cooling part, 1
'5...Snake pipe. (33) Procedural amendment (voluntary) 1. Case Description 1982 Patent Application No. 7. ! 5217 No. 2, Name of the invention: Glass for metal sealing 6, Name of the person making the amendment: Nippon Electric Vacuum Glass Co., Ltd. 4, Agent: 105 Address: 1-4-10-6, Nishi-Shinbashi, Minato-ku, Tokyo, Contents of the amendment ( 1) On page 8 of the specification cylinder, line 8, ``0.2J is corrected to [2, DJ.'' (2) Draw a leader line in red on Figure 1 of the attached drawing. 2 -

Claims (1)

[Claims] 1. Weight percentage: 5lo261.2-65. o, A
t2o35, 0''' 7.8, B20320.2
~22.6, Na201.0-1.9°KOl, 5~
2.5. Li201,0~2.0, BaOO~2.
0, ZnO0-3.8, P2O50,2-1.
0, As2030-0.3,5b2030-0.3
9. A synthetic composition of each component selected from within the range of 9.
Average linear expansion coefficient between 30℃ and 380℃ is 44 to 48×l
Glass for metal sealing, characterized in that it has a transition temperature of 470°C to 480°C.