JP2794360B2 - Bonding method of materials to be bonded selected from metals and ceramics, and bonding agent used therefor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for joining objects to be joined selected from metals or ceramics and a joining agent used therefor, and more particularly to a method for joining fine particles selected from metals or metal oxides having a particle diameter of 100 nm or less. The present invention relates to a method for bonding metals, a metal and ceramics or ceramics using a bonding agent in which a metal or metal oxide powder having a larger particle diameter is uniformly dispersed in a polymer layer, and a bonding agent.

[0002]

2. Description of the Related Art Ceramics have the characteristics of high heat resistance and high hardness, but have the disadvantage that they are weak to mechanical and thermal shocks. Combine this with metal to make up for this,
Alternatively, combining the same ceramics having different characteristics expands the use. As described above, the composite technology (joining technology) of ceramics and ceramics or metal is one of the important elemental technologies of the ceramic processing technology.

[0003] By the way, the joining method of ceramics and metal with ceramics is PbO, CaO, Al.
_A method using a paste containing a metal oxide such as ₂ O ₃ or MgO as a bonding agent, or a Ti-based, Zr-based, Be-based
System, a method using a paste-like bonding agent containing an active metal such as TiH ₂ system, also Mo-Mn-based, Mo system, a refractory metal W system or the like and metallizing at the welded material surface, on the surface thereof A method is used in which Ni plating and metal brazing are applied, and the other surface of the material to be joined is Ni-plated and then joined at a high temperature.

Further, as another method, a DC voltage application method of joining a ceramic and a metal by applying a voltage with the ceramic side being a positive pole and the metal side being a negative pole at a high temperature has been adopted.

[0005]

However, in the above-mentioned joining method using a paste containing a metal oxide and an active metal as a joining agent, strong joining can be obtained irrespective of the type of ceramics, but the joining temperature is high. Since the metal used for the bonding agent is easily oxidized, there is a problem that a strong bonding force cannot be obtained unless the materials to be bonded are bonded together in a vacuum or an inert gas.

In addition, the method using a Mo—Mn-based metal requires metallizing, plating, and the attachment of a metal braze, resulting in an increase in man-hours.
It was necessary to metallize the metal at a high temperature equal to or higher than the melting point of o-Mn. The present invention solves such problems. By using a metal or metal oxide fine particle dispersed in a polymer layer as a bonding agent, bonding can be performed even in air, and metal It is an object of the present invention to provide a method for joining materials to be joined selected from metals or ceramics, which can be joined at a temperature much lower than the melting temperature of the same, and a joining agent used therefor.

[0007]

That is, in the bonding method of the present invention, Ni, Co is added to a polymer composite in which fine particles selected from a metal or metal oxide having a particle diameter of 100 nm or less are dispersed in a polymer. , Cr, Mo, little has been selected from the group consisting of Mn
Kutomo one metal or in addition to the bonding agent obtained the additive powder consisting of oxides, is interposed between the bonding surfaces of the bonding material selected from metal or ceramics, the
The material to be joined is heated in the air to decompose and evaporate the polymer of the composite, metallize the fine particles , and then cool to cool the metal.
Joining the materials to be joined by forming a tarizing layer
And a method of joining materials to be joined selected from metals or ceramics.

The bonding agent of the present invention is selected from metals or metal oxides having a particle diameter of 100 nm or less dispersed in a polymer as a bonding agent used for a material to be bonded selected from metal or ceramics. And at least one metal selected from Ni, Co, Cr, Mo, and Mn having a larger particle diameter than the fine particles, or an additive powder of these oxides. The bonding agent may be in the form of a film, a thin film made of a vapor-deposited film, or a paste.

According to the present invention, a dispersion of fine particles having a particle diameter of 100 nm or less made of metal or metal oxide serving as a bonding agent dispersed in a polymer can be exposed to a high temperature in an atmosphere of air during bonding. Since the polymer is oxidatively decomposed, the polymer is placed in a reducing atmosphere up to the sintering temperature of the fine particles. The metal fine particles are metallized in this reducing atmosphere, and the materials to be joined are strongly joined together. Further, since the fine particles are ultrafine particles of metal or metal oxide, they have the effect of lowering the sintering temperature. Therefore, in the present invention, metal fine particles can be metallized even at a temperature lower by 200 to 400 ° C. than a normal metal melting temperature.

[0010] On the other hand, Ni, Co, Cr, Mo , Mn,
The bonding strength can be improved by adding an additive powder composed of at least one selected metal or an oxide thereof, or a polymer in which these additive powders are dispersed. This is because the added powder improves the wettability with the material to be joined, and also prevents the flow of the joining agent at the time of joining to strengthen the metallized layer.

The bonding agent used in the present invention first melts a polymer material, and then rapidly solidifies the resulting evaporant on the substrate surface to form a thermodynamically non-equilibrated polymer layer. And
After the metal film is brought into close contact with the surface of the polymer layer, the metal film is relaxed until an equilibrium state is reached, and the metal or metal oxide finely divided from the metal layer penetrates into the polymer layer and is dispersed. Was dissolved in a solvent to form a paste, and a small amount selected from Ni, Co, Cr, Mo, and Mn.
It can be obtained by adding and mixing an additive powder composed of at least one kind of metal or oxide or a dispersion of the additive powder in a polymer.

That is, the method for producing the bonding agent is shown in FIGS.
As shown in FIG. 1, the first step is to form the polymer layer in a thermodynamically non-equilibrium state. In this step, as shown in FIG. Vacuum evaporation method in which the polymer layer 2 is solidified on the substrate 1 by melting and evaporating, or the polymer material is melted at a temperature equal to or higher than the melting temperature, and immediately put into liquid nitrogen or the like in this state to be rapidly cooled. Then, there is a melting rapid solidification method of solidifying the polymer layer 2 on the substrate 1. Specifically, in the case of a vacuum evaporation method, a known vacuum evaporation apparatus is used to obtain 10 ^-4 to 10 ^-6 To.
The polymer layer 2 can be obtained on a substrate 1 such as glass at a vacuum of rr and a deposition rate of 0.1 to 100 μm / min, preferably 0.5 to 5 μm / min. In the rapid solidification method, a polymer material is melted and cooled at a cooling rate higher than a critical cooling rate inherent to the polymer material. Specifically, the polymer layer 2 is put into liquid nitrogen to obtain a polymer layer. The polymer layer 2 obtained in this manner is laminated on the substrate 1, placed in a non-equilibrium state thermodynamically, and transitions to an equilibrium state over time.

The polymer material used here is a thermoplastic polymer such as nylon 6, nylon 66, or the like.
Nylon 11, Nylon 12, Nylon 69, High density polyethylene (HDPE), Low density polyethylene (LDP
E), polyvinylidene fluoride (PVDF), polyvinyl chloride, polyoxymethylene, and the like, and are not particularly limited.

Subsequently, as shown in FIG. 2, the polymer layer 2 in the thermodynamic equilibrium state is shifted to a step of attaching a metal layer 3 to the surface thereof. In this step, the metal layer 3 is deposited on the polymer layer 2 by the vacuum deposition apparatus,
Alternatively, the metal layer 3 is laminated on the polymer layer 2 by, for example, bringing a metal foil or a metal plate into close contact with the solidified polymer layer 2. The metal material is gold, silver, copper, iron, zinc, cerium, or the like, and is not particularly limited.

The composite in which the metal layer 3 and the polymer layer 2 thus obtained are in close contact with each other is heated or allowed to stand, and the polymer layer 2 is shifted to an equilibrium state. In this step, it is desirable to promote the relaxation state of the metal-coated polymer layer in a thermostat at a temperature lower than the melting temperature of the polymer material. As a result, as shown in FIGS. 3 and 4, the metal of the metal layer 3 becomes metal or metal oxide fine particles 4 having a particle diameter of 100 nm or less, preferably 50 nm or less, and more preferably 15 nm or less. 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 also decreases and eventually disappears. Therefore, in order for the entire metal layer 3 to become the metal or metal oxide fine particles 4 and be dispersed in the polymer layer 2, it is necessary to adjust the thickness thereof. The fine particles 4 include a metal such as gold, silver, and platinum, and a metal oxide such as Cu ₂ O, Fe ₃ O ₄ , and ZnO.

When the polymer layer 2 is heated in this step,
The polymer layer 2 shows a specific coloring depending on the particle diameter of the metal or metal oxide, and the metal or metal oxide fine particles 4
It can be seen that has penetrated into the polymer layer 2. The color varies 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 the fine particles 4 are dispersed, as shown in FIG. 4, the fine particles 4 are separated and dispersed independently without being aggregated. Moreover, since the metal or metal oxide fine particles 4 are dispersed in the polymer layer 2 in a stable state, the polymer composite 5 of the present invention has excellent oxidation resistance and stable physical properties such as conductivity. Moreover, it is excellent in stability over time.

When the amount of the fine particles 4 made of a metal or metal oxide in the polymer composite 5 is 0.1 vol% or more, preferably 1 vol% or more, more preferably 5 vol% or more, and when less than 0.1 vol%, The metallizing layer of fine particles at the joint interface may not be uniform,
It becomes difficult to join the materials to be joined.

Subsequently, as shown in FIG. 5, the polymer composite 5 is made of a small material selected from Ni, Co, Cr, Mo, and Mn.
At least one kind of additive powder 6 made of a metal or an oxide thereof having a particle diameter of 0.1 to 100 μm or a polymer in which the additive powder 6 is dispersed is mixed with the polymer composite 5 at this time. -A paste dissolved in cresol, 1.2-dichloroethane, acetone or the like. Also, a mixture of the polymer composite 5 and the additive powder 6 or a polymer in which the additive powder 6 is dispersed can be dissolved in the solvent to form a paste.

The bonding agent 7 is preferably a paste,
It may be a solid such as a film. The solid bonding agent 7 can be made into a paste dissolved in a solvent, and can be adhered to the bonding surface of the material to be bonded. In particular, in the paste of the bonding agent 7, the fine particles 4 are uniformly dispersed without aggregation due to the presence of the polymer 8 dissolved in the solvent. In the bonding agent 7, the weight ratio of the added amount of the metal or metal oxide fine particles 4 to the added powder 6 having a larger particle diameter is 0.1 to 5 for the fine particles 4 and 1 for the added powder 6. .

Thus, the bonding agent 7 isFewer materials to be joined
Apply to at least one joint surfaceInterposed between materials to be joineddid
rear,thisThe polymer 8 of the bonding agent 7 is decomposed and evaporated by heating.
Metallizing metal fine particlesThen cool and metallidine
The members to be joined are joined by forming a metal layer.In this case
The heating temperature is 200-400 ° C lower than the melting temperature of the metal.
The metal particles are metallizedLayer formed
ReAs a result, the materials to be joined are joined.

The reason is that the fine particles 4 made of metal or metal oxide in the bonding agent 7 used in the present invention are used.
Is smaller by about 1/10 to 1/100 than the particle diameter of the metal fine particles used for ordinary various applications, and has an effect of lowering the sintering temperature of the fine particles 4. Specifically, when gold (melting temperature 1063 ° C.) and copper (melting temperature 1083 ° C.) are used as the material of the fine particles, this bonding agent is metallized even at a temperature of 750 ° C.

Further, it is difficult to use C in air.
When a polymer composite containing fine particles of u ₂ O is used as the bonding agent 7, Cu ₂ O in the polymer 8 is reduced to Cu in a reducing atmosphere state, and the materials to be bonded are bonded.
Moreover, the additive powder 6 improves the wettability with the material to be joined, prevents flow during joining, and strengthens the metallized layer.

Materials to be joined used in the present invention include Au, Ag, Cu, Ti, Ni, Mo, Mn, W,
Metals such as Ta, Fe, Cr and alloys thereof;
iC, Si ₃ N ₄ , Al ₂ O ₃ , ZrO ₂ , MgO, T
Ceramics such as iN and SiO ₂ glass. The combination of the materials to be joined is metal-to-metal, metal-to-ceramic, or ceramic-to-ceramic.

[0025]

According to the present invention, since fine particles having a particle diameter of 100 nm or less made of a metal or a metal oxide serving as a bonding agent are dispersed in a polymer, even when exposed to a high temperature in an atmosphere of air during bonding. Since the polymer is oxidatively decomposed at or at the sintering temperature of the fine particles, the polymer is placed in a reducing atmosphere. The metal fine particles are metallized in this reducing atmosphere, and the materials to be joined are strongly joined together. Moreover,
Since the fine particles are ultrafine particles of metal or metal oxide, they have the effect of lowering the sintering temperature, so that the metal fine particles can be metallized even at a temperature 200 to 400 ° C. lower than the normal metal melting temperature. On the other hand, Ni, C
The bonding strength is increased by adding at least one kind of metal selected from o, Cr, Mo, and Mn or an additive powder composed of these oxides or a polymer in which these additive powders are dispersed. Can be improved. This is because the added powder improves the wettability with the material to be joined, and also prevents the flow of the joining agent at the time of joining to strengthen the metallized layer.

[0026]

Next, the present invention will be described in more detail with reference to specific examples. Example 1 (Preparation of bonding agent) First, a predetermined polymer pellet was put into a tungsten board by a vacuum evaporation apparatus, and the pressure was 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 base material (glass plate) placed on the upper part of the mounting base is set to 10 ⁻⁴ to 10 ⁻⁴ .
A polymer layer as a vapor-deposited film having a thickness of about 5 μm was obtained at a rate of about 1 μm / min at a degree of vacuum of 10 ⁻⁶ Torr. The molecular weight of the polymer layer is about 1/2 to 1/10 that of the pellet. Further, copper is wound around a tungsten wire, heated and melted, and vapor-deposited under a vacuum of 10 ^-4 to 10 ^-6 Torr, a copper vapor-deposited film is deposited on the polymer layer, and the glass plate on which the laminated film is deposited is removed. Take out from the vacuum deposition equipment, 12
It was left in a thermostat maintained at 0 ° C. for 10 minutes to obtain a composite. As a result, the copper color on the film surface disappears and the entire film is transparent.
It changed to yellow-green .

The sample obtained in this manner was incident at an incident angle of 0.5 °.
Thin film X-ray diffractometer (RINT1200 manufactured by Rigaku Denki)
Was used to measure the X-ray diffraction pattern of the same sample. In the X-ray diffraction pattern, it was found that copper was changed to Cu ₂ O (copper oxide) and the fine particles were dispersed in nylon 11.

When the particle diameter of the fine particles of Cu ₂ O is observed from a transmission electron micrograph, the average particle diameter is about 1 μm.
0 nm, and the addition amount was 18 vol%. A polymer composite in which 18 vol% of Cu ₂ O was atomized and dispersed in nylon 11 was dissolved in m-cresol at a weight ratio of 1: 1 to obtain a paste.
o, Cr, Ni) according to Table 1 was used as a bonding agent. The particle diameters of the Co powder, Cr powder and Ni powder were 2 μm, 10 μm, and 1 to 5 μm, respectively.

[0029]

[Table 1]

A bonding agent comprising the composition shown in Table 1 was applied to both surfaces of the material to be bonded shown in Table 2 using a knife.
After drying in the air for 0 minutes, the material to be joined was joined at 500 ° C. for 10 minutes with a load of 100 g. The sample was placed on a support having a distance between fulcrums of 60 mm, and the central part between the fulcrums was pressed at a bending speed of 1 mm / min to measure the three-point bending strength.

[0031]

[Table 2]

Table 3 shows the results. According to this, it is understood that the bending strength of the present example is improved as compared with the comparative example.

[0033]

[Table 3]

[0034]

As described above, in the present invention, the particle diameter of 100
At least one kind of metal selected from Ni, Co, Mo, and Mn, or an additive powder composed of these oxides, or an additive thereof, in a polymer in which fine particles selected from metals or metal oxides of nm or less are dispersed. When a bonding agent obtained by mixing powders dispersed in a polymer is used for a material to be bonded selected from metals or ceramics, even in the air and at a lower bonding temperature, the composite can be used. by decomposing evaporate polymer layer microparticles were metallizing
Later, by cooling to form a metallizing layer ,
This has the effect that the material to be joined can be joined more firmly.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a method for producing a bonding agent used in the present invention, showing a state after a polymer is formed on a base material.

FIG. 2 is a longitudinal sectional view showing a state in which a metal layer is attached on a polymer layer.

FIG. 3 is a longitudinal sectional view showing a state after a polymer layer with a metal layer is heated.

FIG. 4 is a longitudinal sectional view of a polymer composite constituting the bonding agent of the present invention.

FIG. 5 shows a state of a paste-like bonding agent put in a container.

[Description of Signs] 1 Base material 2 Polymer layer 3 Metal layer 4 Fine particles 5 Polymer composite 6 Additive powder 7 Binder 8 Polymer

────────────────────────────────────────────────── ─── Continuation of the front page Examiner Ryuji Hibino (56) References JP-A-62-216980 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) B23K 35/00-35 / 40 C04B 37/00-37/02 B22F 3/02 B22F 7/06

Claims (8)

(57) [Claims] 1. A polymer composite in which fine particles selected from a metal or a metal oxide having a particle diameter of 100 nm or less are dispersed in a polymer composite containing at least one selected from Ni, Co, Cr, Mo, and Mn.
Both are interposed between one of the metal or bonding surface of the bonding material bonding agent obtained by adding an additive powder consisting of oxides, selected from metal or ceramics, the target
The bonding material is heated in air, after metallizing the fine particles and decomposing vaporized polymer of the composite, meta and cooled
Joining the materials to be joined by forming a rising layer
A method for joining materials to be joined selected from metals and ceramics. 2. The polymer composite according to claim 1, wherein the polymer composite is a thin film.
A joining method of a material to be joined selected from the metals or ceramics described in the above. 3. The method according to claim 1, wherein the polymer composite is in the form of a paste. 4. A polymer mixed with at least one metal selected from Ni, Co, Cr, Mo, and Mn or an additive powder composed of these oxides, and a metal or metal oxide having a particle diameter of 100 nm or less. 2. The method according to claim 1, wherein a mixture of a polymer composite in which the selected fine particles are dispersed is used. 5. A fine particle selected from a metal or metal oxide having a particle diameter of 100 nm or less dispersed in a polymer, and a metal or metal oxide as a bonding agent used for a material to be bonded selected from ceramics. Ni with a large particle size,
A bonding agent comprising at least one kind of metal selected from Co, Cr, Mo, and Mn, or an additive powder of these oxides. 6. The bonding agent according to claim 5, wherein the polymer composite is a paste dissolved in a solvent. 7. The bonding agent according to claim 5, wherein the additive powder comprising at least one metal selected from Ni, Co, Cr, Mo, and Mn or an oxide thereof has a particle size of 0.05 to 100 μm. . 8. Fine particles selected from a metal or metal oxide having a particle size of 100 nm or less, and Ni, Co, Cr, M
The joining according to claim 5, wherein the weight ratio of the amount of the added powder of at least one metal selected from o and Mn or the oxide of these oxides is 1 to 5 for the fine particles and 0.1 to 5 for the added powder. Agent.