JPH04350147A - Alloy for glass sealing - Google Patents

Abstract

PURPOSE:To obtain an allay in which its thermal expansibility is equal to those of the conventional 42%Ni-6%Cr-Fe allay having excellent low thermal expansibility, and, furthermore by the reduction of nonferrous elements, Fe3O4 having high bonding strength with glass is made to easy to form to increase the working efficiency of glass sealing and superior to the 42%Ni-6%Cr-Fe allay in the overall sealability. CONSTITUTION:This is an allay for glass sealing constituted of, by weight, 30 to 37% Ni, 1 to 10% Cr, <=0.1% C, <=0.015% O, <=0.025% N, <=0.05% P and <=0.05% S, furthermoer constituted of, as auxiliary components, one or two kinds of 0.1 to 1% Si and 0.05 to 1% Al and the balance Fe with inevitable impurities, and an allay for glass sealing in which its grain size is regulated to >=8.0 in size number.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an alloy for sealing soft glass in electronic parts.

0002

[Prior art and problems] As an alloy conventionally used for sealing with soft glass, 42%Ni-6%Cr-Fe alloy has a coefficient of thermal expansion that matches that of soft glass, and has a high sealing strength. It is often used because it is good.

This conventional 42%Ni-6%Cr-Fe alloy is first treated with Cr in wet hydrogen as a preliminary treatment for sealing.
is preferentially oxidized and then sealed with glass in the atmosphere. At this time, Fe3O4 having a strong bonding force with glass is formed, and good sealing strength with glass is obtained.

However, since the 42%Ni-6%Cr-Fe alloy contains 48% of non-ferrous elements including Ni and Cr,
In normal processing, Fe3O4 is not sufficiently formed, and it takes too much time to form Fe3O4 sufficiently.

[0005]

[Means for solving the problems] The present invention has been made in view of this point, and provides an alloy that has a low coefficient of thermal expansion, excellent glass sealing properties, and can be efficiently sealed with glass. It is something to do.

[0006] Namely, Ni is less than 30 to 37%, Cr is 1 to 10%, C is less than 0.1%, O is less than 0.015%, N is less than 0.025%, P is less than 0.05%, S0.0
5% or less, Si0.1-1% and Al0.
The present invention relates to an alloy for glass sealing comprising one or two of 05 to 1%, the balance being Fe and unavoidable impurities, and an alloy for glass sealing having a crystal grain size of 8.0 or more in the alloy.

[0007]

DETAILED DESCRIPTION OF THE INVENTION Next, the reasons for limiting the composition of the alloy of the present invention will be explained. Ni has the greatest influence as an element on compatibility with glass, that is, on adapting to the thermal expansion characteristics of glass. If the Ni content is less than 30%, the thermal expansion coefficient becomes high and the thermal expansion characteristics become incompatible with glass. Moreover, if it exceeds 37%, the content of non-ferrous elements becomes too high and it becomes difficult to form Fe3O4, which is also economically disadvantageous. For this reason, the Ni content was set to less than 30 to 37%.

Cr is an element that greatly affects compatibility with glass and sealing strength. As the content of Cr increases, the coefficient of thermal expansion increases. Therefore, by controlling the contents of Ni and Cr in accordance with the glass used for sealing, it is possible to finely adjust the thermal expansion characteristics of the alloy of the present invention to the optimum one. However, the Cr content is 10%
If it exceeds , the coefficient of thermal expansion becomes too large, making it unsuitable for glass sealing.

Furthermore, prior to sealing the alloy of the present invention with glass, an oxide film is formed on the surface as a preliminary treatment, and the glass is sealed through this oxide film, but the sealing strength depends on this oxide film and the alloy base. It also depends on the adhesion with gold. In order to improve the adhesion between the oxide film and the alloy base metal, it is necessary to preferentially oxidize chromium and form a chromium oxide film in the preliminary treatment. For this purpose, the Cr content must be 1% or more. Based on the above, the Cr content was set to 1 to 10%.

[0010] When C is contained in an amount exceeding 0.1%, bubbles are likely to be formed in the glass during sealing, and the sealing strength is significantly deteriorated. For this reason, the upper limit of the C content was set at 0.1%.

[0011]O is an element that greatly affects the formation and sealing of the oxide film, and if it is contained in an amount exceeding 0.015%, the oxide film will become uneven and the density of the oxide film will deteriorate, resulting in poor sealing strength. is significantly impaired. Furthermore, in the worst case, bubbles may be formed in the glass during sealing, which is undesirable. Therefore, the upper limit of the O content was set at 0.015%.

[0012] Like O, N is also an element that greatly affects the sealing property, and if it is contained in an amount exceeding 0.025%, the sealing strength is significantly impaired, so the upper limit of the N content is set at 0.025%.

[0013] When P is contained in an amount exceeding 0.05%, oxidation unevenness tends to occur, so the upper limit is set at 0.05%.

[0014] If S exceeds 0.05%, oxidation unevenness tends to occur and the adhesion between the oxide film and the base metal decreases, so the upper limit is set at 0.05%.

Next, as a subcomponent, Si forms a concentrated layer of Si between the Cr oxide layer and the base metal during oxidation treatment,
It improves the adhesion between the oxide film and the base metal, but if it is less than 0.1%, it is ineffective, and if it is more than 1%, the thermal expansion characteristics change and workability deteriorates, which is not preferable.

[0016] Al improves the adhesion strength between the oxide film and the alloy base metal, but if it is less than 0.05%, it has no effect, and if it is contained in more than 1%, the thermal expansion characteristics change, which is not preferable.

The alloy components of the present invention have been explained above, and it has been confirmed that even better sealing properties can be stably obtained by appropriately controlling the crystal grain size of these alloys. That is, when the crystal grain size is 8.0 or more, excellent sealing properties are obtained. Next, the present invention will be explained in detail with reference to examples.

[0018]

[Examples] Table 1 shows examples of the alloys of the present invention and comparative examples.

[Table 1] After each alloy was vacuum melted and cast, heat treatment and rolling were repeated to produce a plate with a thickness of 0.3 mm. The thermal expansion coefficient of this sample was measured, and the sealing strength was determined by degreasing the surface of this sample, heating it in wet hydrogen at 1050°C for 20 minutes to form an oxide film on the surface, and then sealing it with glass. The adhesion strength was determined and evaluated by a tensile test.

Sample No. 1 to 10 are the alloys of the present invention,
The comparative alloy for this is No. 11-18. The alloy of the present invention has a coefficient of thermal expansion α30-350 of 9×10-6/℃
It is compatible with glass and has an adhesion strength of 5.
It has a high value of 0 Kg/mm2 or more, making it suitable as a sealing alloy.

On the other hand, comparative alloy No. Since alloys Nos. 11 to 17 are out of the range of components of the present invention, their thermal expansion coefficients are too high or too low, or their adhesion strength is insufficient, making them unsuitable as sealing alloys. Also, comparative alloy No. 18
is a 42%Ni-6%Cr-Fe alloy, but its overall adhesion strength is inferior to the alloy of the present invention.

Next, regarding the influence of crystal grain size, the present invention alloy No. 2 and no. Table 2 shows the results of the test using No. 9 as the test material.

[Table 2] Table 2 shows that as the crystal grains become smaller, the adhesion strength improves. Therefore, in order to stably obtain excellent sealing properties, it is effective to set the crystal grain size to a grain size number of 8.0 or more.

As described above, the alloy of the present invention has excellent sealing properties and is an inexpensive, industrially extremely useful alloy that can sufficiently replace the conventional 42% Ni-6% Cr-Fe alloy.

[0023]

Effect of the invention: As a result, the thermal expansion properties are equivalent to the conventional 42%Ni-6%Cr-Fe alloy, which has excellent low thermal expansion properties, and the bonding strength with glass is improved by reducing the amount of non-ferrous elements. Strong Fe3O4 is easily formed, increasing glass sealing efficiency and improving overall sealing performance to 42% Ni-
An alloy superior to the 6% Cr-Fe alloy was obtained. Also,
The alloy of the present invention has a lower content of expensive Ni than conventional alloys, so it is inexpensive and is an extremely excellent alloy.

Claims (2)

[Claims] Claim 1: Ni 30 to less than 37% by weight, Cr
1 to 10%, C 0.1% or less, O 0.015% or less, N
0.025% or less, P 0.05% or less, S 0.05% or less, Si 0.1-1% and Al 0.05-1% as subcomponents.
An alloy for glass sealing consisting of one or two types of 1%, the balance being Fe and unavoidable impurities. 2. The glass sealing alloy according to claim 1, wherein the crystal grain size is 8.0 or more.