JP2020001986A - Low thermal expansible low melting point composition, joint material, and conjugate - Google Patents

Abstract

To provide a low melting point joint material applied to a joint target having a surface consisting of low thermal expansible inorganic oxide and/or metal and capable of jointing them excellently by a heat treatment in air and a temperature range of not exceeding 500°C.SOLUTION: There is provided a low melting point composition containing Ag, I and O, and containing an aggregate of various compound manufactured by binding cation and anion and represented by the formula MQ, wherein M represents cation with valence of m and Q represents anion with valence of q, and satisfying following conditions based on percentage of the compounds (mol%), which are AgI is over 82 to 99, and AgOis 0.1 to 17, when anions other than oxide ion (O) are represented as binding with Ag ion, and containing one or more kind selected from VO, MoO, WO, MnO, ZnO, BO, GeO, PO, SbO, BiO, and TeOof total 0.1 to 7.9.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an inorganic composition, and more specifically, to a low-thermal-expansion low-melting-point composition, a bonding material containing the same, and a bonded body using the same.

Low thermal expansion of _{SiO 2 -ZnO-B 2 O 3} -Li 2 O-Al 2 O 3 based glass, known as materials which can be printed on the thermal expansion properties of low substrate _(Si 3 _{N 4} or quartz glass) ing. The temperature required for baking this glass is 600-700 ° C. (Patent Document 1).

On the other hand, inorganic sealing materials containing Ag ₂ O, MoO ₃ or WO ₃ , and AgI are known as low melting point sealing materials (Patent Documents 2 and 3).

  However, there has not been developed any inorganic composition which can be baked on a material having low thermal expansion and has a temperature required for baking lower than the above. For this reason, a low melting point inorganic bonding material suitable for bonding such materials is not known.

JP 2013-103871 A International Publication No. 2017/068802 WO 2017/068864 A

  An object of the present invention is to apply to a joining object having a surface made of a low thermal expansion inorganic oxide and / or metal, and to have a low temperature range of not more than 500 ° C., preferably not more than 450 ° C. in air. An object of the present invention is to provide a low-melting-point joining material that can favorably join them by heat treatment. A further object of the present invention is to provide a joined body such as an electronic component joined by such a joining material.

  The present inventors have studied the thermal expansion coefficient of a low melting point composition containing AgI as a constituent element. When AgI is contained in a certain amount or more, the thermal expansion coefficient after being heated and melted and cooled and solidified is reduced. It was unexpectedly found to drop sharply. It has also been discovered that such a composition also has joint properties by heat treatment at a temperature not exceeding 500 ° C. The present invention has been completed by further studying the composition ratio of the composition and the bondable temperature. That is, the present invention provides the following.

1. A low melting point composition comprising Ag, I, and O as essential constituents, wherein a cation and an anion are combined, wherein a formula MQ _{m / q} [where M is a cation having a valence of m, Q represents an anion having a valence of q. And the anion other than the oxide ion (O ²⁻ ) is all bound to the Ag ion, the ratio of these compounds is as follows:
AgI More than 82 mol% to 99 mol%,
AgO _1/2 0.1 mol% to 17 mol%,
The filled, and _{VO 5/2, MoO 3, WO 3} , MnO 2, ZnO, BO 3/2, GeO 2, PO 5/2, SbO 5/2, BiO 3/2, 1 kind selected from the TeO ₂ Or containing at least 0.1 mol% to less than 7.9 mol% in total.
Low melting point composition.
2. The low melting point composition according to 1 above, which has fluidity at 500 ° C. and has a coefficient of thermal expansion of 40 × 10 ⁻⁷ / K or less after being heated, melted and solidified by cooling.
3. The low melting point composition according to 1 or 2, wherein the composition contains at least 0.1 mol% in total of one or more selected from VO _5/2 , MoO ₃ , WO ₃ , GeO ₂ , and TeO ₂ .
4. A low melting point bonding material comprising the low melting point composition according to any one of the above 1 to 3.
5. 4. The low melting point bonding material according to 4 above, comprising 50 to 100% by volume of the low melting point composition and 0 to 50% by volume of a filler.
6. A joined body joined by the low-melting-point joining material according to 4 or 5 above.

The low melting point composition of the present invention can be used as a bonding material as it is or in the form of a mixture with a filler. This joining material is applied to at least one of the joining surfaces (consisting of inorganic oxide and / or metal) of each joining object, and in a state where the surfaces are superimposed, does not exceed 500 ° C. in the air, for example, 450 ° C. Heating in a wide temperature range that does not exceed the melting point allows it to melt and flow well and spread between the planes, and then solidifies by subsequent cooling to cause crystallization, resulting in a relatively low coefficient of thermal expansion of the joining object Even in this case, it is possible to achieve good adhesion with the surface. In particular, according to the low melting point bonding material of the present invention, a good bonding can be achieved even when the thermal expansion coefficient of the bonding target is 40 × 10 ⁻⁷ / K or less.

FIG. 1 is a graph in which the thermal expansion coefficients of Reference Examples 1 to 5 and Examples 1 to 5 are plotted against the AgI content.

  As used herein, the term “low melting point” means that the melting point does not exceed 500 ° C., preferably that the melting point does not exceed 450 ° C.

In defining the composition of the present invention by its components and their quantitative relationships, for convenience, the composition is formed by combining a cation and an anion derived from the raw material for production with the formula MQ _{m / q} [wherein M Represents a cation having a valence of m, and Q represents an anion having a valence of q. ], And all anions other than the oxide ion (O ²⁻ ) are considered to be bonded to the Ag ion. Under the above-mentioned quantitative conditions satisfied by these compounds, the relationship of [moles of Ag ions]> [moles of anions other than oxides × sum of valences] holds.

  The low melting point composition of the present invention has fluidity at a temperature not exceeding 500 ° C, for example, preferably in the range of 250 to 450 ° C, more preferably in the range of 300 to 350 ° C. Accordingly, the composition (or bonding material comprising it) is applied to a set of bonding surfaces of a low thermal expansion set, for example in the form of particles (eg, powder or paste), and the surfaces are bonded. By overlapping and heating to the above-mentioned temperature, it can be made to flow and spread between the surfaces, and then cooled and solidified, so that both are brought into a state of being in intimate contact with the joining surface and can be joined.

  AgI is an essential component in the composition of the present invention. When the content of AgI exceeds 82 mol%, the thermal expansion coefficient of the composition after melt-solidification sharply decreases, and a composition having low thermal expansion is obtained. For lower thermal expansion, the AgI content is preferably more than 85 mol%. Further, in order to obtain a composition suitable for a member having extremely low thermal expansion such as quartz glass, the content is preferably more than 92 mol%.

  On the other hand, AgI alone does not result in a flowable material at temperatures not exceeding 500 ° C. In order to be able to flow at such a temperature, the AgI content is preferably at most 99 mol%, more preferably at most 98 mol%.

AgO _{1/2 is} also an essential component of the composition of the present invention. AgO _1/2 has the effect of lowering the liquidus temperature of the composition. For its effect, the content of AgO _1/2 is 0.1 to 17 mol%, preferably 0.2 to 16 mol%, more preferably 0.3 to 15 mol%.

_{VO 5/2, MoO 3, WO 3} , MnO 2, ZnO, BO 3/2, GeO 2, PO 5/2, SbO 5/2, BiO 3/2, 1 or 2 or more selected from TeO ₂ Is also an essential component of the composition of the present invention, and has the effect of lowering the liquidus temperature of the composition, allowing flow at 500 ° C. or lower, and thus enabling bonding of objects at such temperatures. Having. For the use of these _{effects, VO 5/2, MoO 3, WO} 3, MnO 2, ZnO, BO 3/2, GeO 2, PO 5/2 in the _composition, SbO 5/2, _{BiO 3/2,} the total content of TeO ₂ is preferably less than 0.1 to 7.9 mol%, more preferably 0.2 to 7 mol%, more preferably 0.3 to 6 mol%.

VO _5/2 , MoO ₃ , WO ₃ , GeO ₂ , and TeO ₂ are particularly easy to lower the liquidus temperature of the composition, and their contents are preferably 0.1 mol% or more, more preferably 0 mol% or more in total. 0.2 mol% or more, more preferably 0.3 mol% or more.

In the low melting point composition of the present invention, the content of PO _5/2 is preferably 3 mol% or less, more preferably 1 mol%, since there is a possibility of corroding the iron-based metal when the object to be bonded is an iron-based metal. Mol% or less.

  In the low melting point composition of the present invention, AgF, AgCl, and AgBr may corrode iron-based metal when the object to be bonded is iron. Therefore, the total content of AgF, AgCl, and AgBr is preferably 3%. Mol% or less, more preferably 0.1 mol% or less.

  The compositions of the present invention may contain components not listed above. However, from the viewpoint of preventing adverse effects on the water resistance of the composition of the present invention, the total amount of the alkali metal oxides is preferably 5 mol% or less, more preferably 1 mol% or less, and 0.1 mol% or less. % Is more preferable.

  The composition of the present invention may be provided in the form of a mixture of various raw material reagent powders that have been prepared in advance so that the raw material mixture is heated, melted, and solidified by cooling to give the desired low melting point composition. In addition, a material in which a solid solution, a double halide, and a glass phase are formed, which is obtained by heating and melting such a mixture and then rapidly cooling the mixture, can also be used. If a solid solution, a double halide, or a glass phase is formed, the composition is likely to be melted by heating for a shorter time, and thus a composition in such a form is more preferable. The composition of the present invention can also be produced by reacting and precipitating an aqueous solution containing an acid, a base, or a salt according to the composition.

  Further, the bonding material of the present invention can be processed into powder, beads, sheets, rods, or the like and used as the bonding material. From the viewpoint of improving workability, a powdery material can be mixed with water, an organic solvent, a dispersant, a thickener, or the like, and used as a paste-like joining material.

  Further, from the viewpoint of adding performance, for example, in order to impart conductivity, the bonding material of the present invention has a form containing a conductive filler such as metal (for example, metallic silver) or carbon nanotube. In order to provide thermal conductivity, a filler containing high thermal conductivity (for example, aluminum nitride, silicon carbide, etc.) can be used. Further, in order to improve the mechanical strength of the joining material, the joining material may be in a form containing a fibrous or plate-like filler.

  These fillers may be blended as part of the components of the joining material of the present invention in accordance with the performance required according to the use mode and use environment of the joining object. The upper limit of the filler content in the joining material for maintaining the fluidity of the joining material is approximately 50% by volume.

  When the joining material of the present invention is used, the joining object may be one whose surface is made of various metals and nonmetals (such as inorganic oxides). When the object to be joined is Ti, Cr, Cu, Zn, Al, or an alloy containing many of these, the object to be joined is present on the surface to be joined by heating the object in an oxygen atmosphere or performing alumite treatment. It is preferable to use the oxide film after thickening it.

The joining material of the present invention is particularly preferably used when the coefficient of thermal expansion of the member to be joined is very small (for example, 40 × 10 ⁻⁷ / K or less, 30 × 10 ⁻⁷ / K or less). is there. The coefficient of thermal expansion referred to here is an average coefficient of linear expansion between 30 and 100 ° C.

  The joining material of the present invention crystallizes during cooling after heating and melting in the joining process, and has a low thermal expansion coefficient. In order to make the degree of crystallinity close to 100%, it is possible to carry out a treatment for maintaining the bonding material at a temperature higher than the glass transition point of the low melting point composition and lower than the liquidus temperature for a certain time. Such a treatment can be performed, for example, by holding at 150 ° C. for about 1 minute to 1 hour, but is not limited to this.

  When joining objects using the joining material of the present invention, the working atmosphere may or may not contain oxygen. At the time of joining, pressure can be applied to the joining object to further enhance the adhesiveness, and the joining material can be subjected to vibration such as ultrasonic waves to promote melting.

  The bonding material of the present invention is used not only as a bonding material alone, but also to improve the airtightness of the bonding portion by overcoating a portion already bonded with a heat-resistant resin such as a silicone resin. However, it can be used. The bonding conditions (temperature and time) at the time of overcoating are preferably as low as possible and / or as short as possible in order to prevent deterioration of the heat-resistant resin.

  The bonding material of the present invention can be used for bonding members in the manufacture of various electronic components, for example, quartz oscillators, semiconductor devices, SAW devices, and organic EL devices. In addition, it can be used to join members in the manufacture of various components that require the prevention of leakage of low molecular weight and low atomic weight gas such as hydrogen and helium and the maintenance of vacuum.

  Hereinafter, the features of the present invention will be described more specifically with reference to examples, but it is not intended that the present invention be limited to these examples.

[Reference Examples 1 to 6, Examples 1 to 12]
According to Tables 1 to 3, the raw materials were weighed and blended so as to be 5 g in total at the blending ratio shown for each composition, and crushed and mixed in a mortar to obtain a powder. 5 g of the obtained powder was placed in a porcelain crucible. The crucible was placed in a furnace heated to 500 ° C. to 650 ° C. in the atmosphere, and held for 10 minutes to melt the raw material mixture. Each composition was obtained as a bulk by flowing the melt onto a graphite plate at room temperature and rapidly cooling it.

[Evaluation of physical properties]
The physical properties of each bulk obtained above were evaluated by the following methods.

1. Evaluation of coefficient of thermal expansion Each bulk of Reference Examples and Examples was heated at 150 ° C. for 1 hour to sufficiently crystallize. The crystallized bulk was cut into a column having a diameter of 5 mm and a height of 15 mm to obtain a sample. The temperature of the columnar sample and the standard sample formed of quartz glass were raised from room temperature at 10 K / min using a thermomechanical measuring device (model name “TMA8310”, manufactured by Rigaku Corporation) to obtain a thermal expansion curve. The measurement was performed, and the values of the thermal expansion coefficients observed from 30 ° C to 100 ° C were averaged to obtain the thermal expansion coefficient of each sample.

2. Evaluation of Fluidity Each of the bulks of the examples and the comparative examples was cut into a cube of 3 mm × 3 mm × 3 mm to obtain samples. Each sample sandwiched between two 26 mm square, 1.2 mm thick glass plates was placed in an electric furnace. After the temperature was raised to 350 ° C., 400 ° C., 450 ° C., or 500 ° C. at 5 ° C./min, the temperature was maintained for 1 hour, the heating was stopped, and the sample was allowed to cool. The sample was visually observed at room temperature. The observation items and evaluation criteria are as follows.
○: The sample flowed and the two glass plates were joined.
X: The sample did not flow, and the two glass plates were not joined.

As shown in Tables 1 to 3 and FIG. 1, when the AgI content exceeds 82 mol%, the coefficient of thermal expansion of the composition sharply decreases. That is, another correlation significantly different from that predicted from the correlation of AgI-thermal expansion coefficient in the lower AgI mol% region is observed at an AgI content of 82 mol% or more. Further, the composition of the example shows fluidity at 500 ° C. or less and has a coefficient of thermal expansion of 40 × 10 ⁻⁷ / K or less after cooling and solidification, whereas the composition of the reference example has these two properties. No one has been able to balance the properties.

The joining material containing the low melting point composition of the present invention can be used for joining low thermal expansion members such as silicon nitride and quartz glass, and is useful.

Claims (6)

Ag, a low melting composition comprising as a component of I, and O required, made by bonding a cation and an anion, wherein MQ m _{/ q} [the formula, M of valency m cations, Q represents an anion having a valence of q. And the anion other than the oxide ion (O ²⁻ ) is all bound to the Ag ion, the ratio of these compounds is as follows:
AgI More than 82 mol% to 99 mol%,
AgO _1/2 0.1 mol% to 17 mol%,
The filled, and _{VO 5/2, MoO 3, WO 3} , MnO 2, ZnO, BO 3/2, GeO 2, PO 5/2, SbO 5/2, BiO 3/2, 1 kind selected from the TeO ₂ Or containing at least 0.1 mol% to less than 7.9 mol% in total,
Low melting point composition. 2. The low melting point composition according to claim 1, which has fluidity at 500 ° C., and has a coefficient of thermal expansion of 40 × 10 ⁻⁷ / K or less after being heated and melted and solidified by cooling. The low melting point composition according to claim 1, wherein the composition contains at least 0.1 mol% in total of one or more selected from VO _5/2 , MoO ₃ , WO ₃ , GeO ₂ , and TeO ₂ .   A low melting point bonding material comprising the low melting point composition according to claim 1.   The low melting point bonding material according to claim 4, comprising 50 to 100% by volume of the low melting point composition and 0 to 50% by volume of a filler. A joined body joined by the low melting point joining material according to claim 4 or 5.