JPH04182065A - Method for joining materials to be joined selected from metal or ceramics and joining material used therefor - Google Patents

Abstract

PURPOSE:To firmly join a joined material by interposing a polymer combined substance wherein fine metallic particles of <= specified nm are diffused in a polymer layer between the joined surfaces of a metallic combined material and decomposing and evaporating the polymer layer of the combined substance to metallize the fine particles. CONSTITUTION:Polymer combined substance 2 wherein fine particles selected from metal or metallic oxide of <=1000nm are diffused is interposed between composite materials 1, 3 selected from metal or ceramics and the polymer layer 2 of the combined substance is decomposed and evaporated in the air, then, the fine particles are metallized to join the joined materials 1, 3 firmly.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for joining objects selected from metals or ceramics using a polymer composite in which fine particles are dispersed, and a joining material used therefor. , for details 1,000
The present invention relates to a method and a bonding material for bonding metals together, metals and ceramics, or ceramics together using a polymer composite in which fine particles selected from metals or metal oxides of nm or less are uniformly dispersed in a polymer layer.

[Prior Art] Ceramics have the characteristics of high heat resistance and high hardness, but on the other hand, they have the disadvantage of being weak against mechanical and thermal shock.

To compensate for this, it is necessary to combine ceramics with metals, and the range of uses can be expanded by combining ceramics with different characteristics. In this way, a composite wave of ceramics and ceramics or metals I! (Joining technology) has become one of the important elemental technologies of ceramic processing technology.

By the way, methods for joining ceramics and metals include PbO, CaO1A1203, Mg
A method using a paste containing metal oxides such as O as a bonding material, or a method using a paste bonding material containing active metals such as Tl-based, Zr-based, Be-based, TiH2-based, etc. - After metallizing the surface of the adherend with a high-melting point metal such as Mn-based, Mo-based, or W-based metal, applying Ni plating and metal solder to that surface, and then plating the other adherend with Ni. , a high temperature bonding method is used.

In addition, as another method, a DC voltage application method has been adopted in which ceramics and metals are bonded by applying a voltage at high temperature with the ceramic side set as a positive pole and the metal side set as a negative pole.

[Problems to be Solved by the Invention] However, with the bonding method that uses a paste containing the metal oxide and active metal as a bonding material, strong bonding can be obtained regardless of the type of ceramic, but the bonding temperature is high and Since the metal used for the bonding material is easily oxidized, there is a problem in that strong bonding force cannot be obtained unless the adherends are bonded together in a vacuum or in an inert gas.

In addition, the method using MO-Mn metal requires metallizing, plating, and metal soldering, which increases the number of man-hours, and above all, the metal is metallized at a high temperature higher than the melting point of Mo-Mn. There was a need.

The present invention solves these problems, and by using a bonding material in which fine particles of metal or metal oxide are dispersed in a polymer layer, bonding can be performed even in the air. An object of the present invention is to provide a method for joining materials selected from metals or ceramics, which enables joining at a temperature far lower than the melting temperature of the material, and a joining material used in the method.

[Means for Solving the Problems] That is, the bonding method of the present invention has a 1,000 nm thickness in the polymer layer.
A polymer composite in which fine particles selected from the following metals or metal oxides are dispersed is interposed between the joining surfaces of objects to be joined selected from metals and ceramics, and the polymer layer of the composite is placed in the air. The present invention is a method of joining materials selected from metals and ceramics by decomposing and evaporating the particles and then metalizing the fine particles.

In addition, the polymer composite used as the bonding material is a film,
It may be a thin film made of a vapor-deposited film or a paste.

According to the present invention, a polymer composite in which fine particles of 1,000 nm or less made of metal or metal oxide used as a bonding material are dispersed in a polymer layer can be used even when exposed to high temperatures in an air atmosphere during bonding. Since the polymer layer is oxidatively decomposed at or before the sintering temperature of the particles, it is placed in a reducing atmosphere. In this reducing atmosphere state, the metal fine particles are metallized and the materials to be joined are strongly joined together. Furthermore, since the fine particles are ultrafine metal or metal oxide, they have the effect of lowering the sintering temperature.

Therefore, in the present invention, the melting temperature is 200 to
Metal fine particles can be metallized even at temperatures as low as 400°C.

The bonding material used in the present invention melts a polymer material, and then rapidly solidifies the resulting evaporated material on the underlying surface to form a thermodynamically non-equilibrium polymer layer. After a metal film is brought into close contact with the surface of the polymer, the metal film is relaxed until it reaches an equilibrium state, and the finely divided metal or metal oxide from the metal layer is permeated into the polymer layer and dispersed.

That is, as shown in FIGS. 1 to 4, the bonding process of the bonding material is as follows: (1) First, as a first step, the polymer layer is molded into a thermodynamically non-equilibrium state; Specifically, this process includes, for example, a vacuum evaporation method in which a polymer material is heated in a vacuum to melt and evaporate to solidify a polymer layer 2 on a base 1, or a polymer material is melted at a temperature higher than its melting temperature. death,
There is a melting and rapid solidification method in which the polymer layer 2 is immediately poured into liquid nitrogen or the like in this state and rapidly cooled to solidify the polymer layer 2 on the base 1. Specifically, in the case of a vacuum evaporation method, a known vacuum evaporation apparatus is used at a vacuum degree of 10-4 to 1 O-Torr and a evaporation rate of 0.1 to 100 μm/min, preferably 0.
The polymer layer 2 can be obtained on a substrate such as glass at a rate of 5 to 5 μm/min. In addition, in the melting and rapid solidification method, a polymer material is melted, cooled at a cooling rate higher than the critical cooling rate unique to the polymer material, and then poured into, for example, liquid nitrogen to obtain a polymer layer. (As shown in FIG. 1) The polymer layer 2 thus obtained is laminated on the base 1 and placed in a thermodynamically non-equilibrium state, which transitions to an equilibrium state with the passage of time.

The polymer material used here is a thermoplastic polymer, such as nylon 6, nylon 66, nylon 11
, nylon 12, nylon 69, high density polyethylene (
HDPE), low density polyethylene (LDPE), polyvinylidene fluoride (PVDF), polyvinyl chloride, polyoxymethylene, etc., but are not particularly limited.

(2) Next, as shown in FIG. 2, the polymer layer 2 in a thermodynamically non-equilibrium state is coated with a metal layer 3 on its surface.
The process moves on to the step of attaching.゛In this step, the metal layer 3 is deposited on the polymer layer 2 using the vacuum evaporation device, or the metal layer 3 is deposited on the polymer layer 2 by a method such as directly adhering a metal foil or metal plate to the solidified polymer layer 2. Laminated on. The metal material includes gold, silver, copper, iron, zinc, cerium, etc., and is not particularly limited.

(3) The thus obtained composite in which the metal layer 3 and the polymer layer 2 are in close contact with each other is heated or allowed to stand naturally to bring the polymer layer 2t into an equilibrium state. In this step, it is desirable to promote the relaxation state of the polymer layer with the metal layer in a constant temperature bath at a temperature below the melting temperature of the polymer material.

As a result, as shown in FIG. 3, the metal in the metal layer 3 becomes fine particles 4 of metal or metal oxide with a particle size of 1,000 nm or less, preferably 300 nm or less, more preferably 1,100 nm or less, and forms within the polymer layer. This state continues until the polymer layer 2 is completely relaxed, and the thickness of the metal layer 3 adhering to the polymer layer 2 decreases until it finally disappears.

(See FIGS. 3 and 4) Therefore, in order for all of the metal layer 3 to become fine particles 4 of metal or metal oxide and to be dispersed in the polymer layer 2, it is necessary to adjust the thickness of the metal layer 3.

The fine particles 4 are made of metal such as gold, silver, platinum, etc., and Cu2O.
, Fe3O4, ZnO, and other metal oxides.

Note that when the polymer layer 2 is heated in this step, the polymer layer 2 exhibits a unique coloration depending on the particle size of the metal or metal oxide, and the fine particles 4 of the metal or metal oxide penetrate into the polymer layer 2. You can see that Further, this color changes depending on the type of metal or metal oxide, the particle size of the metal or metal oxide, and the type of polymer.

In the polymer composite 5 in which fine particles of metal or metal oxide thus obtained are dispersed, the fine particles 4 are separated and dispersed independently, as shown in FIG. 4. That is, in the polymer composite 5, fine particles 4 of metal or metal oxide
Although they are not in contact with each other and the content is small, they have good conductivity. Moreover, since the metal or metal oxide fine particles 4 are stably dispersed in the polymer layer 2, the polymer composite 5 of the present invention has excellent oxidation resistance and stable physical properties such as conductivity. Moreover, it has excellent stability over time.

In the bonding material, the fine particles 4 made of metal or metal oxide are Q, 1vo1% or more, preferably 1vo1% or more,
More preferably 5vo1% or more, 0°1vo1%
If it is less than this, the metallizing layer of fine particles at the bonding interface may not be uniform, making it difficult to bond the materials to be bonded.

The bonding material is a polymer composite film, a thin film made of a vapor-deposited film, or a paste obtained by dissolving the polymer composite in m-cresol, 1,2-dichloroethane, acetone, etc. It can be attached to the bonding surface of Aseptically, the polymer composite can also be deposited directly on the surface of the material to be joined by vapor deposition. Particularly, in a paste of a polymer composite material, the fine particles are uniformly dispersed without agglomeration due to the presence of the polymer dissolved in the solvent.

Bonding material in this way? : After the material to be joined is placed in the darkness,
The metal particles are metallized by heating to decompose and evaporate the polymer in the bonding material. In this case, the metal particles are metalized even if the heating temperature is 200 to 400 degrees Celsius lower than the melting temperature of the metal. Bonding materials bond together.

The reason for this is that the particle size of the metal or metal oxide fine particles in the bonding material used in the present invention is 17.
Since it is about 10 to 1/100 times smaller, it has the effect of lowering the sintering temperature of the fine particles. Specifically, when gold (melting temperature: 1063°C) or copper (melting temperature: 1083°C) is used as the material for the fine particles, this bonding material can be metallized even at a temperature of 750°C.

In addition, the copper mixture Cu2, which is difficult to use in the air,
When a polymer composite containing fine particles of O is used as a bonding material, Cu2O in the polymer composite is reduced by C due to the reducing atmosphere.
It is reduced to u and the materials to be joined are joined.

In addition, the materials to be joined used in the present invention include Au,
Ag, Cu, Ti, Ni, Mo, Mn.

Metals such as W, Ta, Fe, Cr and their alloys, as well as SiC, Si3N4, Al2O3, ZrO2,
Ceramics such as MgO, TiN, Si02 glass, etc. Combinations of materials to be joined include metals together, metals and ceramics, or ceramics together.

Furthermore, the polymer composite used in the joining method of the present invention is
The metal layer 3 may be slightly attached to the surface of the polymer composite 5 shown in the figure. In this case, the amount of the metal or metal oxide fine particles 4 added in the polymer layer may be at least 1% O.1vo. The attached metal layer 3 is sintered at a low temperature due to the reaction of the fine particles dispersed in the polymer layer, and participates in bonding the composite materials, producing the same effect as when the amount of fine particles in the polymer layer is significantly increased. bring.

[Example] Next, the present invention will be explained in more detail with reference to specific examples.

[Example 1] (Preparation of bonding material) First, a predetermined polymer pellet is placed in a tungsten board using a vacuum evaporation device, and the pressure is reduced to 10 −6 Torr. Next, a voltage is applied between the electrodes to heat the tungsten board in a vacuum to melt the polymer, and the tungsten board is mounted on the base (glass plate) placed on the top of the stand.
A polymer layer, which is a vapor-deposited film having a thickness of about 5 μm, was obtained at a vacuum level of 10 −6 Torr at a rate of about 1 μm/min. The molecular weight of this polymer layer is about 1/2 to 1/10 of that of the pellet. Furthermore, the gold wire was wrapped around the tungsten wire, heated and melted, and evaporated under a vacuum of 10-4 to 1 Q-6 Torr to deposit a gold evaporated film on the polymer layer, and this laminated film was attached. The glass plate was taken out from the vacuum evaporation apparatus and left in a constant temperature bath kept at 120° C. for 10 minutes to obtain a composite. As a result, the gold color on the film surface disappeared and the entire film turned transparent red.

The three types of samples thus obtained were subjected to X-ray diffraction pattern tl-measurement using a thin film X-ray diffraction apparatus (RINT1200 manufactured by Rigaku Denki Co., Ltd.) with an incident angle of 0° to 5°. The results are shown in FIG.

In this X-ray diffraction pattern, the solid line represents the laminate of the polymer film and metal film, and the dotted line represents the laminate at 120°C.
The composite is shown after being left in a constant temperature bath for 0 minutes and heat treated. According to this, the diffraction peaks of the respective metals and nylon 11 appear in each solid line pattern, indicating a structure in which a vapor deposited metal film is laminated on a polymer layer of nylon 11. In addition, in each dotted line pattern, the diffraction peak width (half width) of each metal becomes large, indicating that each metal has become fine particles and transformed into a composite dispersed in nylon 11. There is.

It should be noted that when copper is used, the copper changes to Cu20 (copper oxide), and it can be seen that these fine particles are dispersed in the nylon 11.

Figure 6 (metal particles) shows the results of observing the particle size distribution of gold, silver, and copper oxide particles using transmission electron micrographs.
It is shown in FIG. 7 (M fine particles) and FIG. 8 (copper oxide fine particles).

According to this, it can be seen that the average particle diameters of gold and silver are almost the same and are smaller than that of copper oxide.

[Example 2] Gold fine particles were added to the nylon 11 obtained in Example 1 at IQvo1.
% dispersed polymer composite and Cu2 in nylon 11
A polymer composite in which 18vO1% of O was dispersed was peeled off from the underlying glass plate and used.

This bonding material is 60mm long x 10mm wide x 0゜nm thick.
[[One joint area of the stainless steel plate consisting of l (4Qm
mX I Qmm), heat and melt the bonding material and apply it over the entire surface, then overlap the other stainless steel plate, sandwich this between two 5mm thick iron plates, and tighten the four corners. were screwed together with a torque of 40 kg-m, and heated at a predetermined temperature for 10 minutes to join the two stainless steel plates.

The bonding material used in Comparative Example 2-1 had an average particle size of 0°5 to 2.
The bonding material used in Comparative Example 2-2 was prepared by dispersing 5Qwt% of μm gold particles in liquid paraffin, and the average particle size was 10.
Copper particles of ~20 μm are dispersed in liquid paraffin at 5 Qwt%.

The bonding strength of the stainless steel plate thus obtained was determined in terms of tensile strength using a tensile tester. The results are shown in Table 1. Furthermore, by polishing the joint surface of the peeled stainless steel plate, the presence of the substance was confirmed from the X-ray diffraction peak obtained from the polished surface using thin wAX-ray diffraction at an incident angle of 0.5°, and the presence of the substance in the joint material was confirmed. We investigated whether or not the metals were metallized. The results are shown in Table 2.

Table 1 Table 2 Table O: According to the existing results, nylon 11 decomposes and evaporates during the heat treatment, and the metals are metallized on the stainless steel plate, so the metals are not sufficiently bonded to each other. ing.

[Example 3] In this example, Cu was added to the nylon 11 obtained in Example 1.
A polymer composite in which 18 vol 1% of 2O is dispersed is peeled off in the form of a film from an underlying glass plate, a paste prepared by dissolving the polymer composite in m-cresol at a weight ratio of 1:1, and a material to be joined. A polymer composite in which 18vO1% of Cu2O was dispersed in nylon 11 was attached to the surface of the sample in the same manner as in Example 1, and stainless steel plates were joined to each other in the same manner as in Example 2. The heat treatment was performed at 700℃ for 10
It is a minute.

The tensile strength of the stainless steel plates thus obtained and the feasibility of metallizing the joint surfaces were investigated.

The results are shown in Table 3.

Table 3 (Table 3) As described above, the polymer composite used in the present invention can be fully applied as a bonding material regardless of the form of the bonding material.

Example 4] Cu20 was added to nylon 11 by the same method as in Example 1.
T! : A paste made by dissolving a polymer composite in which a Cu vapor deposited film is locally left on the surface and peeling it off from the underlying glass plate in the form of a film and dissolving it in m-cresol at a weight ratio of 1:1. material was used as a bonding material. The materials to be joined are A I 203 and Si3N4, and each material has a length of 60 mm, a width of IQoon, and a thickness of 3 mm.

After applying the above-mentioned bonding material to the surface of one of the materials to be joined, overlap it with the other material, apply a load of 100g to it, and place it in an oven at a predetermined temperature for a predetermined time to obtain a sample of the material to be joined. Ta. This sample is 80mm long x IQmm wide
X thickness is 3mm, and the area where the bonding material exists is 40mmX
It was 10 mm.

The sample was installed on a support part with a distance between fulcrums of 5 Qmm,
Press the center part between the fulcrums at a bending speed of nm/min to
Measured by point bending strength. The results are shown in Table 4.

Table 4 According to the results, even if a polymer composite is used, ceramics can be bonded together at a temperature below the melting temperature of copper and in air.

Furthermore, it can be seen that when the content of fine particles in the polymer composite is large, the bonding strength of the materials to be bonded is high.

[Effect] As described above, in the bonding method of the present invention and the bonding material used therein, a polymer composite in which fine particles of a metal or metal oxide of 1,000 nm or less are dispersed in a polymer layer, It can be used as a bonding material for materials to be bonded selected from ceramics, and even if the bonding temperature is lowered in the air, the polymer layer of the composite is decomposed and evaporated to metallize the fine particles. This has the effect of firmly joining the materials to be joined.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal cross-sectional view showing the manufacturing process of the bonding material used in the method of the present invention, showing the state after forming a polymer layer on the base, and Fig. 2 shows a metal layer on the polymer layer. FIG. 3 is a vertical cross-sectional view showing the state after heating the polymer layer with metal layer, and FIG. 4 is a vertical cross-sectional view showing the state after heating the polymer layer with metal layer. Longitudinal cross-sectional view of an object,
Fig. 5 is a thin MX-ray diffraction pattern diagram of a laminate of a polymer layer and a metal film and a polymer composite, and Fig. 6 is a diagram showing the particle size distribution of fine gold particles dispersed in the polymer composite. FIG. 7 is a diagram showing the particle size distribution of silver fine particles dispersed in the polymer composite, and FIG. 8 is a diagram showing the particle size distribution of copper oxide fine particles dispersed in the polymer composite. 1... Base layer 2... Polymer layer 3... Metal layer 4... Fine particle patent applicant Mitsuboshi Belting Co., Ltd. Figure 1 Figure 2 Figure 3 Figure 5 Figure 28 (degl S diameter (ham) ) Saitachi 4dan (nm) 0 1.25253,75 5.0 &257.513
．． 75 10.011.2512.5 Rough Il [(mouth m) February 18, 1991

Claims (1)

[Claims] 1. A polymer composite in which fine particles selected from metals or metal oxides of 1,000 nm or less are dispersed in a polymer layer is bonded to a composite material selected from metals or ceramics. 1. A method for joining materials selected from metals or ceramics, which comprises interposing the polymer layer of the composite between surfaces and decomposing and evaporating the polymer layer in the air, followed by metallizing the fine particles. 2. The method for joining materials selected from metals or ceramics according to claim 1, wherein the polymer composite is a thin film. 3. The method for joining materials selected from metals or ceramics according to claim 2, wherein the polymer composite has a metal layer on its surface. 4. The method for joining materials selected from metals or ceramics according to claim 1, wherein the polymer composite is in the form of a paste. 5. As a bonding material for materials selected from metals or ceramics, it is a polymer composite in which fine particles selected from metals or metal oxides of 1,000 nm or less are dispersed in a polymer layer. Characteristic bonding material. 6. The bonding material according to claim 5, wherein the polymer composite is a paste dissolved in a solvent.