KR20160121895A - Method for manufacturing Electrical Contact Material using diffusion bonding by jig - Google Patents

Abstract

(A) mixing and sintering silver (Ag) and a contact material comprising a first metal to produce a first billet; (b) casting a second billet using nickel (Ni) or a nickel alloy; (c) forming a third billet by cutting and assembling the first billet and the second billet at a predetermined ratio, and performing diffusion bonding using a jig; (d) extruding and rolling the third billet to form an alloy sheet; And (e) increasing the weldability of the alloy plate through shaping. The present invention also provides a method for manufacturing an alloy-nickel-based electrical contact for a thermostat.
In the present invention, the silver (Ag) alloy layer serving as a contact point is directly bonded to the nickel layer using the diffusion bonding method, thereby forming a sound bonding interface as well as controlling the formation of an oxide layer, The life of the contact can be improved. In addition, the manufacturing cost and manufacturing time required for the degassing process can be reduced through the joining method using a jig. Further, the lower nickel layer can be processed into a button shape through shape processing, thereby improving the welding strength.

Description

TECHNICAL FIELD [0001] The present invention relates to a method of manufacturing an electrical contact for a thermostat using a diffusion bonding method using a jig,

The present invention relates to a diffusion bonding method using a jig and a method of manufacturing a silver-nickel-based electrical contact for a thermostat using the same.

Among the diffusion bonding methods, hot isostatic pressing (HIP) is a method of diffusing the object to be processed under high temperature by applying pressure to the object in the same direction. The isotropic pressure bonding method is used for diffusion of large raw materials such as billets It is a way to enable bonding. However, The degassing process must be carried out to obtain adequate strength.

In the degassing process, a can made of Sus is sized to fit into a can, and then a billet to be bonded to the inside of the can is sealed and sealed by welding. Thereafter, It is a process to remove gas. In the canning process, a degassing process is required to remove the gas inside the can in the form of a large capsule in order to prevent oxidation and the like. In addition to this, degassing costs are relatively high, and after the HIP process, The process cost for removing it is required.

Disclosure of Invention Technical Problem [8] Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and it is an object of the present invention to provide a method of manufacturing a semiconductor device, And it is an object of the present invention to provide a novel manufacturing method of an electrical contact capable of reducing the process cost and shortening the process time without further performing the removing process.

In order to achieve the above object, the present invention provides a method for manufacturing a billet, comprising the steps of: (a) mixing and sintering silver (Ag) and a contact material comprising a first metal to produce a first billet; (b) casting a second billet using nickel (Ni) or a nickel alloy; (c) forming a third billet by cutting and assembling the first billet and the second billet at a predetermined ratio, and performing diffusion bonding using a jig; (d) extruding and rolling the third billet to form an alloy sheet; And (e) increasing the weldability of the alloy plate by shaping the alloy plate. The present invention also provides a method of manufacturing an alloy-nickel-based electrical contact for a thermostat.

The first metal in step (a) may be at least one selected from the group consisting of tin (Sn) and nickel (Ni), wherein the content of the first metal is in the range of 100 wt% And more preferably 10% by weight or more.

According to another preferred embodiment of the present invention, the step (c) may be carried out by diffusion at a temperature of 700-850 ° C and a pressure of 50-110 MPa for 1 to 10 hours.

Meanwhile, the present invention provides an alloy-nickel alloy-based electrical contact for a thermostat manufactured by the above method.

The present invention can produce an electrical contact having a good bonding interface and a good bonding strength by directly bonding the base material and the electrical contact using a diffusion bonding method.

In addition, it is possible to reduce manufacturing cost and manufacturing time according to existing degassing and can removing process through joining using a jig.

Fig. 1 is an FE-SEM image showing cross-sections of electrical contacts manufactured in Comparative Example 1 (Fig. 1A) and Example 1 (Fig. 1B).
Fig. 2 is a graph showing the results of bonding strength of the electrical contacts manufactured in Example 1 and Comparative Example 1. Fig.

Hereinafter, the present invention will be described in detail.

In the present invention, the diffusion contact is applied to manufacture the electrical contact for a thermostat, thereby improving the life of the electrical contact by controlling the formation of the oxide layer, which is likely to occur on the bonding interface, as well as forming a healthy bonding interface .

More specifically, the joining proceeds in the state of a billet, and the same pressure is applied by using a jig for joining with a round billet.

That is, in the case of the joining method using the conventional can, the pressure is applied isostatically but in the case of joining using a jig, the pressure is applied in the vertical or horizontal direction, (Plat), the bonding strength can be increased rather than the method using the can. As a result of this bonding, it is confirmed that the bonding strength is similar to or higher than that of the billet using the existing Can, and it has a sound bonding interface (see FIGS. 1 and 2).

In addition, the canning process using a conventional can requires a relatively expensive degassing cost of several hundred thousand won per billet, and the process cost of easily bonding the SUS material can and silver billet during the process is removed . In contrast, according to the present invention, the use of a jig not only reduces the process cost to a level of 1/10 to 1/20, but also improves the fairness and economical efficiency since no SUS material is used.

≪ Manufacturing method of electrical contact >

Hereinafter, a method of manufacturing an alloy-nickel-based electrical contact for a thermostat according to the present invention will be described. However, the present invention is not limited to the following production methods, and the steps of each process may be modified or optionally mixed as required.

(A) mixing and sintering a contact material comprising silver (Ag) and a first metal to produce a first billet ('S10'); (b) casting a second billet using nickel (Ni) or a nickel alloy ('S20'); (c) cutting and assembling the first billet and the second billet at a predetermined ratio, and forming a third billet by diffusion bonding them using a jig ('S30'); (d) extruding and rolling the third billet to form an alloy sheet ('S40'); And (e) increasing the weldability of the alloy plate through shaping ('S50').

Here, the step (e) can be further embodied by forming a strip formed after slitting the alloy plate into a button shape.

Hereinafter, the manufacturing method will be described separately for each process step as follows.

(a) a first billet casting (hereinafter referred to as 'S10 step'),

First, a first billet is manufactured using a contact material containing silver (Ag) and a first metal.

More specifically, after a composition of a contact material containing silver (Ag) as a main component and containing a first metal is designed, a metal powder having such a composition is mixed and charged into a mold and sintered to form a circular first billet do.

Here, the size of the circular first billet is not particularly limited, and may be, for example, 110 +/- 10 mm in diameter and 200 +/- 10 mm in length.

The first metal may be selected from the group consisting of cadmium (Cd), tin (Sn), indium (In), and nickel (Ni), as long as it is a contact material capable of forming a silver- , And more preferably at least one of nickel (Ni). The content of the first metal is preferably 10% by weight or more, more preferably 15 to 40% by weight based on 100% by weight of the first billet.

(b) Second billet casting (hereinafter referred to as " S20 step &

In step S20, the second billet is cast using nickel (Ni) or a nickel alloy.

Here, the casting means that the molten material is made into a billet, which is a metal ingot in a form that can be easily extruded later. At this time, the size and shape of the billet are not particularly limited, and may be the same as or different from the step S10. For example, it is preferably the same as the first billet in the step S10.

The nickel alloy may have a composition containing nickel (Ni) as a main component and a second metal contained therein.

In this case, the second metal is not particularly limited as long as it is a contact material capable of forming an alloy with nickel in the art, and may be copper (Cu), for example, and its content is not particularly limited either.

(c) Manufacturing of a third billet (hereinafter referred to as 'step S30') through diffusion bonding using a jig

In step S30, the first billet and the second billet are cut at a predetermined ratio, and the first billet and the second billet are cut together to form a third billet.

 Wherein the cutting ratio of the first billet to the second billet is suitably adjustable within the conventional range known in the art.

On the other hand, in step S30, a silver (Ag) alloy layer and a nickel (Ni) or copper-nickel alloy layer are bonded to each other through equi-direction diffusion bonding to form a third billet, do.

When the jig is used as described above, the same effect as that of utilizing the conventional canning can be exhibited. At this time, canning requires canning removal process after diffusion bonding, and it is an important way to reduce the manufacturing process and reduce the cost by using the jig several times.

In the case of joining without using a conventional jig, the pressure required for diffusion is not sufficiently applied, so that there is a problem that the joining is not performed due to insufficient driving force, or only the joining is partially performed. On the other hand, the jig employed in the present invention presses the jig in a vertical direction so that the jig can be well bonded over the entire surface, so that the bonding strength can be increased.

The material of the jig usable in the present invention is not particularly limited, and it is preferable to use a material that does not react with the first billet and the second billet and does not react during the heat treatment. The jig is mainly made of a carbon material, for example, graphite or alumina. Although the shape of the jig is not particularly limited, it is preferable that the shape of the jig is designed to be the same size as the billet or slightly smaller than the size of the billet, and to provide an appropriate coupling force.

In a preferred example of step S30, the circular first billet and the second billet are charged into the jig device, respectively, and subjected to diffusion bonding by application of heat and pressure. At this time, the positions of the first billet and the second billet are not particularly limited, and the upper and lower positions can be appropriately changed as necessary. Further, the configuration and the shape of the jig device are not particularly limited, and may have a configuration or a shape similar to the mold device known in the art, for example.

The method and conditions for the diffusion bonding using the jig can be appropriately adjusted within the range known in the art. As a preferable example of step S40, the third billet may be maintained at a temperature of 700-850 DEG C and a pressure of 50-110 MPa for 1-10 hours.

When the Ag alloy-nickel (Ni) or copper-nickel contacts are maintained under the above-described conditions, junctions are formed by diffusion between atomic phases across their entire contact surfaces. That is, the bonding is performed by diffusion between the silver (Ag) alloy layer and the nickel layer or the copper-nickel layer interface. At this time, if it is lower than the above condition, a local alloy layer is formed only at the interface, and if it is higher than the above condition, the settling of the contact becomes large, and the contact performance can be deteriorated.

The bonding layer formed by the diffusion bonding is mainly composed of silver alloy, nickel, and copper-nickel, and when the contact is an alloy, the alloy component is further included. Such a bonding layer has a melting point higher than that of a conventionally used silver-containing layer and also has a high-temperature strength, so that it is difficult to peel off the temperature rise due to energization of a large current. The bonding strength can be equivalent to the contact strength by soldering.

In addition, since the thickness of the bonding layer can be controlled by heating temperature, heating time, pressure, etc., it is possible to control to a desired value according to the characteristics of the bonding portion.

The third billet produced through the diffusion bonding as described above can further improve the bonding strength through a process such as hot compression.

(d) Alloy plate formation (hereinafter referred to as 'S40 step')

In this step S40, the diffusion-bonded third billet is extruded and rolled to form a silver alloy-nickel or nickel alloy plate (or strip).

As a preferable example of the method for forming the alloy plate, the third billet is put into a metal mold in a strip form and then hot extruded at a pressure of 160 to 180 kgf / cm ² at a temperature of 600 ° C to 700 ° C .

In this step S40, the extrusion is a step of manufacturing the contact material in a form to press-contact. As such, when the extrusion is carried out, depending on the mold, the surface may be rough, foreign matter, and oxides may be generated, and it is necessary to finish the surface through a brush or an acid treatment process if necessary.

The contact material in the form of a strip or plate contact can be produced by the extrusion process. When the extrusion method is carried out in this way, the distribution of the oxides which are likely to be formed on the crystal grains and the bonding surfaces can be controlled. Therefore, the strip material (alloy plate) manufactured in this manner is less likely to cause cracks and defects in the base material, thereby improving the durability and reliability of the product.

Then, the contact material is rolled to a desired thickness to match the desired thickness.

The rolling may be performed by conventional hot rolling, cold rolling or both, which are known in the art. More specifically, the strip may be subjected to hot rolling at a temperature of 300 to 450 DEG C or by cold rolling to a desired dimension . And can be manufactured by cutting to a desired width through a slitting process.

(e) slitting and button shape fabrication (hereinafter referred to as 'S50 step'),

Then, the alloy plate is subjected to a brushing process and a leveling process according to a conventional method known in the art, and then a slitting process is performed. At this time, depending on the surface condition required by the user, it is possible to adjust the degree of processing of the surface.

A process of increasing the weldability through shaping of the slitted alloy plate is performed. For example, the slit strip material is shaped into a button shape by rolling.

The method of producing the above button shape is not particularly limited, and can be produced under the conventional methods and conditions known in the art. For example, a button can be manufactured by rolling using a shape rolling roll.

At this time, the button shape may be formed in both the upper and lower portions, or the button may be formed in the lower layer and the upper layer may be formed in a round shape.

In the present invention, welding is mainly performed using a resistance welding method. In this case, when a button shape is provided, the current is concentrated to the button side and is easily bonded. Actually, the bonding strength is about 30% depending on the presence or absence of the button shape.

The present invention also provides an alloy-nickel-based electrical contact for a thermostat produced by the above-described method.

The electrical contact of the present invention includes an alloy layer in which silver (Ag) is mixed with a first metal (such as Ni), an alloy bonding layer (bonding layer) of silver (Ag) and nickel, a nickel or nickel alloy layer , Cu-Ni). Since they form a sound bonding interface, they are excellent in bonding strength, durability and reliability. The material of the electrical contact may have a structure of 2 to 4 layers, and may be formed by inserting other different materials as necessary.

The electrical contact of the present invention is mainly used for a thermostat, and can be used as a contact material for other circuit breakers, switches, relays, switches, and the like. And other technical fields in which other electrical contact materials can be usefully applied.

Hereinafter, the present invention will be described in more detail with reference to Examples. However, the following Examples are intended to illustrate one embodiment of the present invention, but the scope of the present invention is not limited by the following Examples.

[Example 1]

90 wt% of silver (Ag) and 10 wt% of nickel (Ni) were mixed, and the mixture was charged into a mold and sintered to form a circular first billet. 100 wt% of nickel (Ni) was cast and a circular second billet was cast.

The prepared first billet and second billet were cut at a ratio of 1: 1 and assembled to prepare a third billet. The third billet was maintained at 850 DEG C and 98 MPa for 4 hours using a jig.

The third billet was indirectly extruded at 190 kgf / cm ² after induction heating at 800 ° C and rolled to a thickness of 0.6 mm to form a silver alloy-nickel alloy sheet. After cutting to a width of 3.5 mm, a nickel alloy surface having a protrusion shape and a silver alloy surface having a round shape were formed. Thus, an electrical contact for the thermostat of Example 1 made of silver alloy-nickel was prepared.

[Comparative Example 1]

90 wt% of silver (Ag) and 10 wt% of nickel (Ni) were mixed, and the mixture was charged into a mold and sintered to form a circular first billet. 100 wt% of nickel (Ni) was cast and a circular second billet was cast.

The prepared first billet and second billet were cut at a ratio of 1: 1 and assembled to prepare a third billet. The third billet was degassed and maintained at 850 DEG C at 98 MPa for 4 hours.

The third billet was indirectly extruded at 190 kgf / cm ² after induction heating at 800 ° C and rolled to a thickness of 0.6 mm to form a silver alloy-nickel alloy sheet. After cutting to a width of 3.5 mm, a nickel alloy surface having a protrusion shape and a silver alloy surface having a round shape were formed. Thus, an electrical contact for a thermostat of Comparative Example 1 made of silver alloy-nickel was prepared.

[Experimental Example 1]

Fig. 1 shows a cross section of the electrical contacts manufactured in Example 1 and Comparative Example 1, respectively. The bond strength results of Example 1 and Comparative Example 1 are shown in Fig.

As a result of the experiment, it was confirmed that the electrical contact of Example 1 bonded by using the jig had a better bonded interface than that of Comparative Example 1, and had excellent bonding strength (see FIGS. 1 and 2) .

Claims (8)

(a) mixing and sintering (Ag) and a contact material comprising a first metal to produce a first billet;
(b) casting a second billet using nickel (Ni) or a nickel alloy;
(c) cutting and assembling the first billet and the second billet at a predetermined ratio, and forming a third billet by diffusion bonding using a jig;
(d) extruding and rolling the third billet to form an alloy sheet; And
(e) increasing the weldability through shaping the alloy plate
Nickel-based electrical contact for a thermostat. ≪ RTI ID = 0.0 > 8. < / RTI > The method according to claim 1,
Wherein the first metal in step (a) is at least one selected from the group consisting of nickel (Ni) and tin (Sn). The method according to claim 1,
Wherein the content of the first metal in the step (a) is 10% by weight or more based on 100% by weight of the first billet. The method according to claim 1,
Wherein the nickel alloy in step (b) is a copper (Cu) -nickel (Ni) alloy. The method according to claim 1,
The step (c) is characterized in that the bonding is carried out by diffusion between the silver (Ag) alloy layer and the nickel (Ni) layer interface by maintaining the pressure at a temperature of 700-850 ° C and a pressure of 50-110 MPa for 1-10 hours Wherein the thermostat is made of an alloy-nickel-based electrical contact. The method according to claim 1,
Wherein the step (c) is performed by using a jig instead of a degassing process using a can. The method of manufacturing a silver-nickel-based electrical contact for a thermostat, The method according to claim 1,
Wherein the step (d) is a step of forming a strip formed after slitting an alloy plate in the shape of a button through a shape rolling process, and the alloy part is formed in the form of a button. Gt; An alloy-nickel-based electrical contact for a thermostat produced by the method of any one of claims 1 to 7.

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