KR102343828B1 - Metal hinge for foldable phone and method thereof - Google Patents

Abstract

The present invention relates to a metal hinge for a foldable phone and a method for manufacturing the same, which is manufactured based on amorphous liquid metal so that folding and unfolding operations are freely performed in response to a flexible display with a very simple configuration, and repeated folding and unfolding over a long period of time It is designed so that it is not easily damaged even when unfolding.

Description

Metal hinge for foldable phone and manufacturing method thereof

The present invention relates to a hinge for a foldable phone, and in particular, it is manufactured based on amorphous liquid metal so that folding and unfolding operations can be freely performed in response to a flexible display with a very simple configuration, and it is easy to perform repeated folding and unfolding operations over a long period of time It relates to a metal hinge for a foldable phone that is not damaged and a method for manufacturing the same.

With the recent development of display technology, as the size of a portable display screen increases, various methods for simultaneously satisfying portability and large-screen display are being studied.

In order to satisfy the large-screen display while maintaining portability, recently, flexible displays that can be folded and unfolded to maximize visibility without breaking the middle fold are on the rise. It is about to be released as a next-generation smartphone.

In such a foldable phone, it is important to secure a flexible display technology that can maintain performance and durability during repeated folding and unfolding operations. It is important.

However, in the case of a hinge for a foldable phone, as can be seen in Korean Patent Application Laid-Open No. 2015-0096827 (2015.08.26.), it has a very complicated structure by itself, and also takes into account the process of manufacturing and assembling each part belonging to the hinge. If so, there was a problem in that huge expenditures were required in the manufacturing process and cost.

Korea Patent Publication No. 2015-0096827 (2015.08.26.)

Accordingly, the present invention has been proposed to solve the problems of the related art as described above, and the object of the present invention is to be manufactured based on amorphous liquid metal so that folding and unfolding operations are freely performed in response to a flexible display with a very simple configuration. , to provide a metal hinge for a foldable phone that is not easily damaged even by repeated folding and unfolding operations over a long period of time, and a method for manufacturing the same.

In order to achieve the above object, the metal hinge for a foldable phone according to the technical idea of the present invention connects the first body and the second body supporting the left and right portions of the flexible display installed on the front, respectively, and at least some of them are folded and It consists of a body having a folded portion less than 1 mm thick to enable an unfolding operation, and is characterized in its technical configuration that it is made of an amorphous alloy as a material.

Here, the amorphous alloy comprises 48 to 68 wt% of zirconium, 9 to 34 wt% of titanium, 9 to 30 wt% of copper, 7 to 9wt% of nickel and 1.2 to 4 wt% of beryllium based on the total weight can do.

In addition, the metal hinge may be characterized in that it consists of a flat body.

In addition, it may be characterized in that a plurality of buffering micropores are formed in the folded portion of the body of the metal hinge to facilitate folding and unfolding operations.

In addition, the buffering micropores of the metal hinge may be characterized in that it is formed by press working or etching.

In addition, the amorphous alloy may have a tensile strength of 780 to 1100 GPa, a hardness of 526 to 630 Hv, and a specific gravity of 4.5 to 6.4, and an elastic modulus of 70 to 100 GPa.

In addition, the metal hinge, at a vacuum degree of 10 ^-3 to 10 ^-2 torr, 3 to 10 wt% of zirconium, 9 to 30 wt% of copper, 7 to 9 wt% of nickel and 1.2 to 4 wt% of beryllium 900 to 950 After preparing the first melt at ℃ temperature, 45 to 58wt% of zirconium is additionally added to the first melt heated to a temperature of 950~1050℃ to prepare a second melt, and 9~34wt in the second melt It may be characterized in that the amorphous alloy manufactured through the processes of preparing a tertiary melt by adding % titanium is injection-molded.

In addition, the tertiary melt is injected into an ingot molding mold in the middle of the amorphous alloy being molded into a metal hinge by injection molding, and then cooled and molded into an ingot having a constant mass shape. It can be characterized.

In addition, after the liquid alloy is injection molded, it is cooled to room temperature at a temperature of 600 to 1200° C. and shrunk with a shrinkage ratio of 0.002 to 0.8% until it is hardened into a metal hinge.

On the other hand, a foldable phone according to the present invention, a flexible display; first and second bodies respectively supporting left and right portions of the flexible display; and a metal hinge that connects the first body and the second body to enable folding and unfolding operations, wherein the metal hinge is the aforementioned metal hinge.

In addition, the present invention folder block manufacturing method of the metal hinge phones according to the degree of vacuum at 10 ^-3 to 10 ^-2 torr for 3 ~ 10wt% zirconium, 9 ~ 30wt% of copper, 7 ~ 9 wt% nickel and 1.2 to 4wt% of beryllium to prepare a first melt at a temperature of 900 ~ 950 ℃; Preparing a secondary melt by additionally adding 45 to 58 wt% of zirconium to the first melt heated to a temperature of 950 to 1050° C. while maintaining a vacuum degree of 10 ^-3 to 10 ^{-2 torr;} Preparing a third melt by adding 9 to 34 wt% of titanium to the second melt while maintaining a vacuum degree of 10 ^-3 to 10 ^{-2 torr;} molding the ingot by injecting the tertiary melt into an ingot forming mold and then cooling; Melting the ingot at a temperature of 600 ~ 1200 ℃ to make a liquid alloy; It is characterized in that it includes a; the step of injecting the liquid alloy into the product mold, injection molding in the shape of a metal hinge, and then cooling.

Here, it may be characterized in that the amounts of oxygen and nitrogen are adjusted to 2500 to 3000 ppm and 200 to 500 ppm, respectively, in the process of preparing the secondary melt by adding the zirconium additionally.

In addition, when the ingot is melted to form a liquid alloy, the temperature may be raised by high-frequency induction heating applying a high frequency while passing the ingot through an induction coil.

In addition, in the step of preparing the tertiary melt, 9 to 34 wt% of titanium added to the secondary melt may be divided and added at least in a plurality of times.

The metal hinge for a foldable phone according to the present invention is manufactured based on amorphous liquid metal so that folding and unfolding operations can be freely performed in response to a flexible display with a very simple configuration, and it is not easily damaged even with repeated folding and unfolding operations over a long period of time It has the advantage that it does not.

In addition, the present invention completely breaks away from the complicated hinge structure so far, and the process for manufacturing and assembling a plurality of parts is not required by the remarkably simplified flat plate structure, thus significantly reducing the manufacturing cost and time required for the manufacturing process. can be significantly shortened.

1 and 2 are diagrams of a use state of a foldable phone to which a metal hinge is applied according to an embodiment of the present invention;
3 is a rear perspective view of a foldable phone to which a metal hinge is applied according to an embodiment of the present invention;
4 is a flowchart for explaining a method of manufacturing a metal hinge according to an embodiment of the present invention;
5 is a graph of experimental results for a metal hinge according to an embodiment of the present invention;
6 is a reference view for explaining an experimental apparatus and an experimental method for a metal hinge according to an embodiment of the present invention;

A metal hinge for a foldable phone and a manufacturing method thereof according to embodiments of the present invention will be described in detail with reference to the accompanying drawings. Since the present invention can have various changes and can have various forms, specific embodiments are illustrated in the drawings and described in detail in the text. However, this is not intended to limit the present invention to the specific disclosed form, it should be understood to include all modifications, equivalents and substitutes included in the spirit and scope of the present invention. In describing each figure, like reference numerals have been used for like elements. In the accompanying drawings, the dimensions of the structures are enlarged than actual for clarity of the present invention, or reduced than actual in order to understand the schematic configuration.

Also, terms such as first and second may be used to describe various elements, but the elements should not be limited by the terms. The above terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, a first component may be referred to as a second component, and similarly, a second component may also be referred to as a first component. Meanwhile, unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by those of ordinary skill in the art to which the present invention belongs. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the related art, and should not be interpreted in an ideal or excessively formal meaning unless explicitly defined in the present application. does not

<Example>

1 and 2 are diagrams of a use state of a foldable phone to which a metal hinge is applied according to an embodiment of the present invention. 3 is a rear perspective view of a foldable phone to which a metal hinge is applied according to an embodiment of the present invention.

As shown, the metal hinge 130 according to the embodiment of the present invention has a first body 120a and a second body 120b that support the left and right sides of the flexible display 110 installed on the front side of the foldable phone, respectively. ) with a simple flat body.

Although the metal hinge 130 according to the embodiment of the present invention is made in the form of a very simple flat plate, it is manufactured based on an amorphous liquid metal material so that folding and unfolding operations are freely performed, and even in folding and unfolding operations over a long period of time. It has physical properties that are not easily damaged.

Hereinafter, the metal hinge 130 according to an embodiment of the present invention will be described in more detail.

The metal hinge 130 according to the embodiment of the present invention can connect the first body 120a and the second body 120b of the foldable phone as simply as possible, unlike the prior art, as shown in FIGS. 1 to 3 . It is possible to make it with only a thin flat body.

The metal hinge 130 of the present invention enables folding and unfolding operations while connecting between the first body 120a and the second body 120b only with such a remarkably simple configuration, and is not easily damaged even in long-term use. The reason is because it was manufactured based on an amorphous liquid metal material, as described above.

In the case of an amorphous alloy, as is known, it was developed to overcome the limitations of crystalline general metals or alloys. There is no crystal lattice, so it has superior wear resistance, corrosion resistance, and oxidation resistance than general metals or alloys. In the case of alloy, since it can soften and flow when heated, injection molding is possible, so it can be said that it is a material suitable for mass production of high-quality foldable phone hinges intended by the present invention.

Furthermore, in the case of the metal hinge 130 according to the embodiment of the present invention, the generally known amorphous alloy is not simply adopted, but a new composition ratio and manufacturing that maximizes the characteristics of the amorphous alloy while excluding beryllium, which is expensive and toxic to the human body. It is noteworthy in that a new amorphous alloy is manufactured and adopted through the process.

The amorphous alloy employed in the metal hinge 130 according to the embodiment of the present invention is 48 to 68wt% of zirconium, 9 to 34wt% of titanium, 9 to 30wt% of copper, 7 to 9wt% of nickel and 1.2 to 4wt % of beryllium, it can be injected at 900~1050℃, has a tensile strength of 780~1100GPa, a hardness of 526~630Hv, a specific gravity of 4.5~6.4, and a modulus of elasticity of 70~100 GPa .

Zirconium (Zr), which is contained in the largest amount in such an amorphous alloy, is an element corresponding to atomic number 40 and has a specific gravity of 6.49 at 20 ° C. According to an embodiment of the present invention, zirconium may be made into an amorphous alloy-like shape or a bulk amorphous alloy-like shape during a manufacturing process. Zirconium can function to improve elasticity and strength, and can improve elasticity, strength, hardness, thermal conductivity, or straightness characteristics while being fused with other metals, and can function to prevent oxidation of metals such as copper.

Titanium (Ti) is a metal having a high hardness corresponding to an atomic number of 22 and a specific hardness about twice that of iron. Titanium is strong enough to have a strength comparable to steel, yet weighs less than half that of steel, does not rust, is silvery and shiny, does not stick to magnets unlike iron, and has low thermal and electrical conductivity. The strength is more than double that of titanium, it has the highest corrosion resistance among stainless steel alloys, and it has a number of advantages that make it an essential element of a lightweight alloy because of its shape memory. As titanium is fused with zirconium, the strength of the amorphous alloy is improved due to the properties of titanium.

Copper (Cu) has an atomic number of 29, an atomic weight of 63.546, a melting point of 1,083°C, and a specific gravity of 8.93 at 20°C. Although copper is soft, it has the strength to resist corrosion and acid, and has the property of being well fused with other metals. In addition, it is rich in malleability and ductility, has good heat and electricity conductivity, and is chemically relatively stable, and the change occurs only on the surface. However, copper does not oxidize in dry air, but is oxidized in moist air, so there is a problem in that it is easily used for rust. As copper is fused with zirconium, it enables compression and melting to a thin thickness due to the low melting temperature of copper. In addition, copper has the advantage of reducing the weight of the alloy as a whole and increasing the elasticity while reducing the manufacturing cost. According to an embodiment of the present invention, zirconium and copper have a function of complementing each other's properties, and the entire alloy has amorphous-like properties. Titanium and copper are melted at a lower temperature than the actual melting temperature of the entire metal in a vacuum state and are mixed with each other.

Nickel (Ni) has an atomic number of 28, an atomic weight of 58.70, a melting point of 1455°C, and a specific gravity of 8.9 at 20°C. Like iron, it can be forged and welded, and has great malleability and ductility. Nickel has strong magnetism, but is weaker than iron. The electrical conductivity is 14.9% of that of copper, and it is safer than iron against air and moisture and is not easily oxidized. It has strong corrosion resistance to alkali.

Beryllium (Be) is an element with atomic number 4, with an element symbol of Be, and is a silver-gray metal at the top of Group 2 element in the periodic table. You can see the improvement effect. In addition, it has a specific gravity of 1.85, is light and hard, and has high thermal conductivity, so it is used in the aerospace field, electricity, electronics, nuclear power, and alloys. However, since beryllium (Be) has a small specific gravity every week, it has the effect of lowering the specific gravity of the entire alloy during alloy manufacturing. In certain countries, such as those using beryllium, products using beryllium are subject to close monitoring, and products with reduced beryllium content are required to be used.

The strength, hardness, and specific gravity of zirconium, titanium, copper, nickel and beryllium can be appropriately adjusted depending on the field of application, and the present invention is optimized with a metal hinge for a foldable phone in mind.

Hereinafter, a method for manufacturing a metal hinge according to an embodiment of the present invention will be described.

4 is a flowchart for explaining a method of manufacturing a metal hinge according to an embodiment of the present invention.

As shown, the method for manufacturing a metal hinge according to an embodiment of the present invention includes a first melt manufacturing step (S110), a second melt manufacturing step (S120), a tertiary melt manufacturing step (S130), and an ingot forming step (S140). , including a liquid alloy forming step (S150), an injection molding step (S160), and a surface processing step (S170).

In the first melt manufacturing step (S110), 3 to 10 wt% of zirconium, 9 to 30 wt% of copper, 7 to 9 wt% of nickel, and 1.2 to 4 wt% of beryllium are mixed in a vacuum melting furnace at a temperature of 900 to 950 ° C. to prepare the first melt. At this time, the chamber in which the melting furnace is installed is formed in a vacuum state so ^{that the degree of vacuum is 10 -3} to 10 ^{-2 torr.} In general, the melting point of zirconium at room temperature becomes 2128K, but some of zirconium begins to melt before reaching the melting point. According to an embodiment of the present invention, zirconium is gradually melted at a low temperature by injecting a part of zirconium together with other metals having a low melting point while vacuuming the melting furnace, so that the zirconium is combined with other metals to form an alloy. To form an alloy, the melting furnace is heated to a temperature of 900 ~ 950 °C in a vacuum.

In this step, vacuum formation facilitates the discharge of gases or gases contained in each component used in the manufacture of the amorphous alloy to remove defects such as bubbles and pores existing in the amorphous alloy. Oxygen and nitrogen are completely It is preferable to maintain the ^{vacuum melting furnace at a vacuum degree of 10 -3} to 10 ^-2 torr in a state in which argon gas, which is removed and an inert gas, is injected. Instead of the argon gas, other inert gases such as helium may be used.

After that, the secondary melt manufacturing step (S120) proceeds. In this step, ^{while maintaining the vacuum degree of 10 -3} to 10 ^-2 torr, the vacuum melting furnace is again heated to 950 to 1050 ° C through high frequency induction heating, and then 45 to 58 wt% of zirconium is additionally added to the first melt to add zirconium as a whole. It is increased so that it becomes 48~68wt%.

As such, the reason for first melting only a portion of zirconium and copper, nickel and beryllium among the entire amorphous alloy composition and then adding zirconium is to suppress excessive emission of gases or bubbles generated inside the alloy composition during the first melting. . Physical properties such as hardness, tensile strength, and elasticity of the resulting amorphous alloy are further improved.

After that, the third melt manufacturing step (S130) proceeds. In this step, a tertiary melt is prepared by adding 9 to 34 wt% of titanium to the secondary melt while continuously maintaining the ^{vacuum degree of 10 -3} to 10 ^{-2 torr.}

Here, 9 to 34 wt% of titanium, which is added to and melted in the secondary melt, is preferably divided and added at least several times. The reason that titanium is divided and melted by adding small amounts in multiple times is because in the case of sponge titanium, which is generally used titanium, if a large amount is added at once within a relatively early time, it causes excessive generation of gas and smoke due to the characteristics of sponge titanium, thereby controlling the vacuum melting furnace. This is because it is difficult and may cause deterioration of the physical properties of the finished amorphous alloy. For reference, sponge titanium refers to the primary alloy used to make titanium products. Titanium ore is reacted with chlorine gas to make titanium tetrachloride, refined, and then reduced with metallic magnesium or metallic sodium. This metallic titanium is made of sponge. Because it is in a state, it is generally called sponge titanium.

After that, the ingot forming step (S140) proceeds. In this step, the tertiary melt is injected into an ingot molding die and cooled to form an ingot having a lump shape, preferably a spherical or similar spherical shape. After the ingot is formed, cooling to room temperature interferes with crystallization so that an amorphous alloy ingot can be manufactured.

In this way, if the ingot forming step (S140) proceeds, it is not necessary to continuously proceed with the processes for manufacturing the amorphous alloy and the process for manufacturing the metal hinge 130 by injection molding from the amorphous alloy, and division of labor can also be performed. Therefore, it is advantageous to build a more efficient production system.

After that, the liquid alloy forming step (S150) proceeds. In this step, the ingot formed in the previous step is melted at a temperature of 600~1200℃ to make a liquid alloy. For this purpose, it is preferable to melt the ingot by applying a high frequency while passing it through an induction coil. The frequency applied to the induction coil may be, for example, 100 Hz to 500 kHz, and melt the ingot into a liquid alloy by bringing it to a temperature of 600 to 1200 °C. Here, the induction coil may have a circular coil shape, a rectangular coil shape, an elliptical coil shape, a pancake coil shape, or a helical coil shape, but is not limited thereto. As such, when the ingot is in a molten state into a liquid alloy, it is ready for injection molding in the product mold.

After that, the injection molding step (S160) proceeds. In this step, the liquid alloy is injected into the product mold to be injection molded into the shape of the metal hinge 130 . What is important here is that the metal hinge 130 is molded inside the closed space while the molten liquid alloy is injected into the product mold. After the metal hinge 130 is molded, the level of shrinkage in the process of cooling the product mold depends on how much. affect product performance. Therefore, the level of contraction needs to be properly controlled. Accordingly, the shrinkage level at this time is preferably 0.002 to 0.8% until cooled to room temperature from a temperature of 600 to 1200° C. at ^{10 −4 Torr to 2 atm.}

After that, the surface processing step (S170) proceeds. In this step, a plurality of buffering micropores 131 are formed by intensively processing the folded portion of the body of the injection-molded metal hinge 130 in which folding and unfolding operations are actually performed. As such, when the buffering micropores 131 are formed in the folded part of the metal hinge 130, the shock caused by the tensile stress and the compressive stress, which are opposite forces generated inside and outside the metal hinge 130 during the folding operation, are buffered. It is possible to effectively suppress damage while the ball 131 absorbs and buffers in the middle. Here, in order to form the buffering micropores 131 in the folded portion of the metal hinge 130, various methods such as press working or etching may be used.

Continuing, below, the physical properties of the metal hinge 130 according to an embodiment of the present invention will be compared and described from various cases of manufacturing the amorphous alloy as the base.

<Example 1>

Step 1: Make the test furnace where the alloy is produced in a ^{vacuum state with a pressure of 10 -3} torr, and put 5 kg of zirconium, 17 kg of copper, 9 kg of nickel, and 3 kg of beryllium into the furnace for testing, and melt the first melt while maintaining the temperature at 930 ° C. was prepared.

Step 2: 45 kg of zirconium was added to the first melt heated to a temperature of 1000° C. and melted to form a second melt.

Step 3: After dividing 21 kg of titanium in the secondary melt, it was added three times to finally form an alloy melt, and then cooled to make an ingot.

<Example 2>

Step 1: Make the test furnace where the alloy is produced in a ^{vacuum state with a pressure of 10 -3} torr, and put 5 kg of zirconium, 21 kg of copper, 9 kg of nickel, and 3 kg of beryllium into the furnace for testing, and melt the first melt while maintaining the temperature at 900 ° C. was prepared.

Step 2: 43 kg of zirconium was added to the first melt heated to a temperature of 950° C. and melted to form a second melt.

Step 3: 17 kg of titanium was divided into the secondary melt three times to form an alloy melt and then cooled to make an ingot.

<Example 3>

Step 1: Make the test furnace where the alloy is produced in a ^{vacuum state with a pressure of 10 -3} torr, and put 5 kg of zirconium, 9 kg of copper, 7 kg of nickel, and 4 kg of beryllium into the furnace for testing, and melt the first melt while maintaining the temperature at 950 ° C. was prepared.

Step 2: 63 kg of zirconium was added to the first melt heated to a temperature of 1050° C. and melted to form a second melt.

Step 3: 9 kg of titanium was divided into the secondary melt twice to form an alloy melt, and then cooled to make an ingot.

<Example 4>

An amorphous alloy was prepared in the same manner as in Example 1, except that the amount of titanium input in step 3 of Example 1 was 34 kg.

<Example 5>

An amorphous alloy was prepared in the same manner as in Example 1, except that the amount of copper input in Step 1 of Example 1 was 30 kg.

<Example 6>

An amorphous alloy was prepared in the same manner as in Example 1, except that the amount of beryllium input in step 1 of Example 1 was 1.2 kg.

The alloy compositions and composition ratios of Examples 1 to 6 were compared with Comparative Examples (Korea Patent Publication No. 2014-0068246, 'alloy of 'injection molding of an amorphous alloy using an injection molding system'), as shown in Table 1 below.

Zirconium (wt%) Titanium (wt%) Copper (wt%) Nickel (wt%) Beryllium (wt%) Example 1 50 21 17 9 3 Example 2 48 17 21 9 3 Example 3 68 9 9 7 4 Example 4 50 34 17 9 3 Example 5 50 21 30 9 3 Example 6 50 21 17 9 1.2 comparative example 46.75 8.25 7.5 10 27.5

<Characteristic test>

For the ingot-shaped alloy prepared from Examples 1 to 6, a hardness test, an elasticity test, and a tensile test were performed with the amorphous alloy prepared according to the composition ratio of the comparative example. Melt viscosity was also measured. Hardness was measured according to the Rockwell Hardness measurement method according to HRC KS B 5530 and expressed as Vickers Hardness (HV), elasticity test according to KS B 5533 and tensile test according to KS B0802 did

<Characteristic test result>

Each characteristic test result of Examples 1 to 6 and Comparative Example was shown in Table 2 below.

Hardness (HV) Modulus of elasticity (GPa) Tensile strength (GPa) Melting point (℃) Example 1 531 95 1087 950 Example 2 526 75 850 973 Example 3 620 70 780 1042 Example 4 585 90 983 1012 Example 5 568 88 952 968 Example 6 594 79 980 996 comparative example 580 72 805 1350

As can be seen in Table 2, Examples 1 to 6 significantly reduced the content of beryllium compared to Comparative Examples, and were equivalent to or higher than Comparative Examples in physical properties such as hardness, elastic modulus, tensile strength and melting point. Excellent. In addition, it was concluded that precision injection was easy, and it was confirmed that the optimal example was Example 1. The reason that Examples 1 to 6 has excellent physical properties equal to or greater than that of Comparative Examples is because the generation of harmful gases or bubbles was suppressed as much as possible while the alloy composition was processed through a total tertiary melting process. analyzed.

<Result of injection processability test>

On the other hand, for the injection processability test of the amorphous alloy, which is the base material of the metal hinge according to the embodiment of the present invention, viscosity change, fluidity change, shrinkage change, and flow rate change according to temperature and pressure change were measured. The change in viscosity was measured based on the change in shear force, and the change in fluidity was measured together with the change in flow rate while changing the diameter from 0.1 mm to 10 cm based on the length of 10 cm. And the viscosity was measured while changing the temperature from 900 to 1050 ℃, and the shrinkage was measured as the volume change. The measurement temperature range was 50 to 1000° C., and the pressure change was measured while changing the pressure applied to the tube having a diameter of 10 cm in the range of 760 Torr to 1620 Torr.

As a result of the measurement, it was found that the amorphous alloy, which is a material that is the basis of the metal hinge according to the embodiment of the present invention, has a viscosity of about 10 to 960 Pas at a temperature of 900 to 1050° C., and each measurement result for the workability test indicators is shown in Table 3 below.

Viscosity liquidity shrinkage flow rate 5-12 9-15 0.03~1 5-10 6-10 7-13 0.07 to 0.26 8-15

The temperature was measured by changing the unit of 10°C and the pressure by the unit of 10 Torr, and each value was expressed as a relative deviation in %. For example, a viscosity of 5 to 12 indicates that the minimum change in viscosity is 5% and the maximum change in viscosity is 12% at the lowest temperature of 900°C and the highest temperature of 1050°C.

As shown in Table 3, it was confirmed that the amorphous alloy has the advantage of having a small change in injection characteristics according to temperature and pressure changes.

<Result of injection processability test>

Continuingly, the experimental results conducted in order to confirm the performance of the metal hinge according to the embodiment of the present invention will be described below.

5 is a graph showing the results of experiments on a metal hinge according to an embodiment of the present invention, and FIG. 6 is a reference diagram for explaining an experimental apparatus and an experimental method for a metal hinge according to an embodiment of the present invention.

In this experiment, as shown in FIG. 6 , folding and unfolding operations were repeatedly performed over 100,000 times using a test device for the metal hinge. At this time, in order to provide the same environment as a mobile device such as a foldable phone, an insertion member (RB) having a folding radius R was inserted and supported inside as a substitute for the body of the foldable phone.

The experimental results are clearly shown in the graph of FIG. 5 , and each of the flat metal hinges having a width of 5 cm, a length of 3 cm, and a thickness of 0.1 mm, each injection molded from the ingot according to the first to sixth examples A, It was classified into B, C, D, E, and F types, and the G type was formed by additionally forming buffering micropores by etching in the folded part of the A type metal hinge.

As a result of the experiment, it was confirmed that all metal hinges were able to perform folding and unfolding operations normally without being damaged for 100,000 times of folding and unfolding operations. However, it was practically meaningless to perform the experiment more than 100,000 times, so no further progress was made. This has been difficult to use since the previous foldable display substrates had a problem of extremely low visibility even after 1,000 folding and unfolding operations. This is because it is no longer meaningless to conduct a folding and unfolding operation test exceeding 100,000 times for the metal hinge according to the embodiments of the present invention in consideration of the fact that R&D is in progress.

Here, in the case of the F-type metal hinge in which micropores are additionally formed, the level of micro-cracks was significantly lower compared to the insignificant level of micro-cracks during the folding and unfolding operations of other types of metal hinges over 90,000 times. This is because, as expected, the buffering micropores formed in the folded part of the metal hinge actually play a role of buffering the influence of tensile stress and compressive stress, which are opposite forces generated in the outer and inner internal structures during the folding operation, in the middle. do.

As such, the metal hinge according to the embodiments of the present invention has durability that maintains a function without damage over a long period of time while flexibly responding to repeated folding and unfolding operations.

Although preferred embodiments of the present invention have been described above, various changes, modifications and equivalents may be used in the present invention. It is clear that the present invention can be equally applied by appropriately modifying the above embodiments. Accordingly, the above description is not intended to limit the scope of the present invention, which is defined by the limits of the following claims.

110: display 120a: first body
120b: second body 130: metal hinge
131: buffering micropores

Claims (3)

As a metal hinge for a foldable phone,
The first body and the second body of the foldable phone that support the left and right parts of the flexible display installed on the front, respectively, are connected to be foldable and unfolded, and made of an amorphous alloy as a material,
The amorphous alloy has a tensile strength of 780 to 1100 GPa, a hardness of 526 to 630 Hv, a specific gravity of 4.5 to 6.4, and an elastic modulus of 70 to 100 GPa,
At a vacuum degree of 10 ^-3 to 10 ^-2 torr, 3 to 10 wt % of zirconium, 9 to 30 wt % of copper and 7 to 9 wt % of nickel were prepared as a primary melt at a temperature of 900 to 950 ° C, and then 950 to 1050 45 to 58 wt% of zirconium is additionally added to the first melt heated to a temperature of ℃ to prepare a second melt, and 9 to 34 wt% of titanium is added to the second melt to prepare the tertiary melt It is manufactured by injection molding an amorphous alloy manufactured through
It consists of a flat body, but at least some of the flat body has a folding part less than 1 mm thick to enable folding and unfolding operations. A metal hinge for a foldable phone, characterized in that a plurality of buffering micropores are formed by etching so as to play a role of buffering the influence of tensile stress and compressive stress, which are forces. delete delete

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