KR20220028609A - Folding plate and manufacturing method thereof - Google Patents

Abstract

The present invention relates to a folding plate and a manufacturing method thereof. The folding plate comprises: a first metal sheet (110) having support units (111, 112) formed on both sides thereof and a bending unit (113) formed in the middle thereof; a second metal sheet (120) joined to the support unit (111) of one side of the first metal sheet (110); a third metal sheet (130) joined to the support unit (112) of the other side of the first metal sheet (110); and a thin film filler layer (140) arranged on the support unit (111) of one side and the support unit (112) of the other side of the first metal sheet (110) to braze and join the first metal sheet (110) and the second metal sheet (120) and braze and join the first metal sheet (110) and the third metal sheet (130). The present invention contributes to reducing the thickness of a foldable phone by manufacturing in a thin thickness, has a heat radiation function and a support function of a display, has excellent bendability, and can prevent bending unit wrinkles even if bending is repeated.

Description

FOLDING PLATE AND MANUFACTURING METHOD THEREOF

The present invention relates to a folding plate and a method for manufacturing the same, and more particularly, to a folding plate applied to a foldable phone to support a display and a method for manufacturing the same.

A foldable phone uses a flexible OLED display so that the screen can be folded. A foldable phone can improve portability through the folding process and has the advantage of being able to use it as a wide screen when unfolded.

The foldable phone can fold or unfold the screen using a hinge, and by placing a folding plate on the back of the display, the folding part is completely folded when folded, and when unfolded, a flat wide screen can be displayed without traces of the folded border.

Such a folding plate should have durability that can be folded and unfolded tens of thousands of times, and it is important to have mechanical durability to support and protect the display part from mechanical stress that may occur during folding.

In addition, it is necessary that the folding plate has a heat dissipation performance capable of dissipating the heat generated by the display by making it thin.

Patent Document 1: Unexamined Patent Publication No. 10-2018-0026598 (published on March 13, 2018)

It is an object of the present invention to provide a folding plate which contributes to reducing the thickness of a foldable phone by manufacturing it to a thin thickness, has a heat dissipation function and a support function of a display, has excellent flexibility and excellent durability, and a manufacturing method thereof.

Another object of the present invention is to provide a folding plate that is thin, light and strong through bonding of dissimilar metals, can prevent wrinkling in bent portions, and can easily dissipate heat, and a method for manufacturing the same.

According to a feature of the present invention for achieving the object as described above, the present invention provides a first metal sheet in which support portions are formed on both sides and a bent portion is formed in the center, and a second metal sheet bonded to one side support portion of the first metal sheet. and a third metal sheet joined to the other support portion of the first metal sheet, and disposed in one support portion and the other support portion of the first metal sheet to braze the first metal sheet and the second metal sheet, and the first metal sheet and the third and a thin film filler layer for brazing bonding metal sheets.

The thin film filler layer may be made of an alloy material including at least one of Ag, AgCu, and AgCuTi.

The thickness of the thin film filler layer may be in the range of 1.0 μm to 10 μm.

The first metal sheet is formed of a stainless (SUS) material, and the second metal sheet and the third metal sheet are formed of copper or a copper alloy material.

The bonding surface of the second metal sheet bonded to the support portion of one side of the first metal sheet and the bonding surface of the third metal sheet bonded to the support portion of the other side of the first metal sheet are the stepped surfaces.

The stepped surface of the second metal sheet and the stepped surface of the third metal sheet overlap the bent portion by a predetermined region and include a non-bonding region that is not bonded to the first metal sheet.

The first metal sheet, the second metal sheet and the third metal sheet form the same plane.

The bent portion is formed of a mesh and the support portion is formed of a flat plate.

The mesh preferably has a line width of at least 0.11 μm.

The second metal sheet and the third metal sheet include recessed grooves etched in a predetermined area.

The depth of the concave groove is 0.05mm~0.25mm.

A step of preparing a first metal sheet having support portions formed on both sides and a bent portion formed in the center, a step of preparing a second metal sheet and a third metal sheet having a stepped surface and a concave groove formed therein, a support portion of one side of the first metal sheet, and disposing a thin film filler layer between the stepped surfaces of the second metal sheet, and between the support portion on the other side of the first metal sheet and the stepped surface of the third metal sheet, and brazing bonding.

In the step of preparing the first metal sheet in which the support portions are formed on both sides and the bent portion is formed in the center, the bent portion is formed in a mesh shape by photo-etching the first metal sheet.

In the step of preparing the second metal sheet and the third metal sheet on which the stepped surface and the concave groove are formed, the stepped surface and the indented groove may be formed by half-etching the second metal sheet and the third metal sheet.

In the step of disposing the thin film filler layer between the one side support of the first metal sheet and the stepped surface of the second metal sheet, the other support of the first metal sheet and the stepped surface of the third metal sheet, paste application, foil (foil) A thin film filler layer having a thickness of 1.0 μm or more and 10 μm or less is disposed by either method of adhesion or P-filer.

In the step of disposing the thin film filler layer between the one side support of the first metal sheet and the stepped surface of the second metal sheet, the other support of the first metal sheet and the stepped surface of the third metal sheet, The stepped surface and the stepped surface of the third metal sheet overlap the bent portion in a predetermined area, and the thin film filler layer is not disposed in a region where the stepped surface of the second metal sheet and the stepped surface of the third metal sheet overlap the curved portion.

The step of brazing bonding is performed at 780 to 900° C., and the upper weight or pressure may be applied during brazing bonding.

The present invention etches a first metal sheet having rigidity to form a mesh-shaped bent portion in the center, and braze-bonds a second metal sheet and a third metal sheet having high heat dissipation performance on both sides to form the same plane. There is an effect that it is possible to manufacture a folding plate of a thin thickness.

In addition, according to the present invention, a thin film filler layer in which a second metal sheet and a third metal sheet are bonded to both sides of the first metal sheet has high bonding strength and heats from the first metal sheet to the second metal sheet and the third metal sheet. It has an excellent effect of heat dissipation efficiency because it transfers heat quickly to

In addition, according to the present invention, the concave groove formed by half-etching the second metal sheet and the third metal sheet has an effect of reducing the weight of the folding plate.

In addition, according to the present invention, the non-bonding region of the second metal sheet and the third metal sheet extended to the rear surface of the bent portion reinforces the rear surface of the bent portion, thereby increasing bending repeatability and preventing wrinkles of the bent portion.

Accordingly, the folding plate of the present invention has an effect of being easily applied to a foldable phone that requires heat dissipation, light weight, and anti-wrinkle protection at the bent portion, which is necessary to secure bending repeatability, has a high demand for heat dissipation, and requires weight reduction.

1 is a diagram illustrating an example of a foldable phone.
2 is a perspective view showing a folding plate according to an embodiment of the present invention.
3 is an exploded perspective view showing a folding plate according to an embodiment of the present invention.
4 is a cross-sectional view showing a folding plate according to an embodiment of the present invention.
5 is a cross-sectional view showing a state in which the folding plate according to the embodiment of the present invention is bent.
6 is a cross-sectional view showing a folding plate according to another embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

The folding plate according to an embodiment of the present invention may be applied to a foldable phone.

The folding plate may be attached to the back of the display of the foldable phone to perform a heat dissipation function and support function of the display.

A foldable phone is a smartphone with a foldable display.

1 is a diagram illustrating an example of a foldable phone.

1 illustrates an in-folding foldable phone 10 in which the left and right sides of the display 11 are folded inward around a vertical axis. The foldable phone 10 includes a secondary display 13 that is viewed in a folded state.

The foldable phone 10 arranges the folding plate 100 on the back side of the display 11 so that the folding part is completely folded when folded, and a flat wide screen can be displayed without traces of the folded border when unfolded.

The folding plate according to the embodiment of the present invention will be described with reference to the shape applied to the foldable phone of the inbolding method shown in FIG. 1 as an example.

2 is a perspective view showing a folding plate according to an embodiment of the present invention.

As shown in FIG. 2 , the folding plate 100 includes a first metal sheet 110 , a second metal sheet 120 , and a third metal sheet 130 . In the folding plate 100 , the first metal sheet 110 is connected between the second metal sheet 130 and the third metal sheet 130 . That is, in the folding plate 100 , the second metal sheet 120 and the third metal sheet 130 are connected to both sides of the first metal sheet 110 like wings.

The folding plate 100 is composed of three metal sheets of the first metal sheet 110 , the second metal sheet 120 , and the third metal sheet 130 and forms the same plane. When the folding plate 100 is formed in the same plane, the thickness is reduced compared to the case where it is formed in multiple layers, so it can contribute to reducing the thickness of the foldable phone.

The first metal sheet 110 is for performing a supporting function and a folding and bending function.

The first metal sheet 110 has a bent portion for a bending function. Specifically, in the first metal sheet 110, the support portions 111 and 112 are formed on both sides in the width direction, and the bent portion 113 is formed in the center between the support portions 111 and 112 on both sides. The bent portion 113 is for improving the flexibility (bending property) of the first metal sheet 110 . The support portions 111 and 112 positioned on both sides of the bent portion 113 are for improving the restoring force of the first metal sheet 110 .

The bent portion 113 is formed of a mesh, and the support portions 111 and 112 are formed of a flat plate. Since the rigid material is difficult to fold, the central part of the rigid material is formed into a mesh so that it can act as a spring. In addition, flat support portions 111 and 112 are formed on both sides of the bent portion 113 to be flattened without any border marks when unfolded. The first metal sheet 110 is completely folded by the bent portion 113 formed of a mesh, and when unfolded, it may be a flat plane without border marks that were folded by the support portions 111 and 112 on both sides.

The mesh constituting the bent portion 113 is formed in a shape in which lines cross each other. Since the bent portion 113 has to have the durability to be folded and unfolded tens of thousands of times, the durability is improved by adopting a shape in which the lines cross each other.

The mesh is formed by photo-etching the central portion of the first metal sheet 110 . If the mesh is formed by punching it with a press, the mesh pattern is not precise. If the mesh pattern is not precise, it is difficult to form the bent portion 113 having a desired elastic force.

The first metal sheet 110 is made of a metal material having rigidity for elasticity and support function. The first metal sheet 110 may be made of an amorphous alloy or stainless (SUS) material. Amorphous may be used as an example of the amorphous alloy. Amorphous is rigid but has poor etching properties. On the other hand, stainless steel has good etchability while being rigid. Therefore, the first metal sheet 110 is preferably made of a stainless material. As the stainless material, SUS 304 and SUS 316 may be used as an example. SUS 304 and SUS 316 have a tensile strength of 550 MPa or more. When SUS 304 or SUS 316 is used as the first metal sheet 110 , it is possible to form a mesh pattern shape having a desired shape due to good etching properties. SUS 304 or SUS 316 may be used with a thickness of 150㎛ ~ 300㎛, SUS 304 or SUS 316 in the embodiment uses a thickness of 150㎛ for weight reduction. The mesh has a minimum line width of 0.11 μm for good bending function.

The second metal sheet 120 is bonded to one side support portion 111 of the first metal sheet 110 , and the third metal sheet 130 is bonded to the other side support portion 112 of the first metal sheet 110 .

The second metal sheet 120 and the third metal sheet 130 are for performing a heat dissipation function and a support function. The second metal sheet 120 and the third metal sheet 130 are formed of a metal material having heat dissipation performance. The second metal sheet 120 and the third metal sheet 130 may be formed of copper or a copper alloy material. When the second metal sheet 120 and the third metal sheet 130 are formed of pure copper, strength may be insufficient. Therefore, the second metal sheet 120 and the third metal sheet 130 are preferably formed of a copper alloy material in order to secure strength as well as a heat dissipation function. As an example, the copper alloy material may be one of C7025, C7035, and PH-1000HS Series. C7025 is a precipitation hardening alloy obtained by precipitation by adding Ni and Si to Cu. It is an alloy with improved strength through precipitation. C7025 and C7035 have a tensile strength of 900 MPa or more and an electrical conductivity of 100 W/m.K.

3 is an exploded perspective view showing a folding plate according to an embodiment of the present invention, and FIG. 4 is a cross-sectional view showing a folding plate according to an embodiment of the present invention.

3 and 4 , in the folding plate 100 , the second metal sheet 120 is bonded to one side support 111 of the first metal sheet 110 , and the other side of the first metal sheet 110 . The third metal sheet 130 is bonded to the support 112 so that the second metal sheet 120 and the third metal sheet 130 having a heat dissipation function are formed on both sides of the first metal sheet 110 having a bending function. It becomes a structure connected like wings.

Step surfaces 121 and 131 are formed in the second metal sheet 120 and the third metal sheet 130 . The stepped surfaces 121 and 131 are for bonding to the first metal sheet 110 . Specifically, the first metal sheet 110 is bonded to the bonding surface 121a of the second metal sheet 120 that is bonded to one side support 111 of the first metal sheet 110 and the other side support 112 of the first metal sheet 110 is bonded to the first metal sheet 110 . 3 The bonding surface 131a of the metal sheet 130 is the stepped surfaces 121 and 131 .

The stepped surface 121 of the second metal sheet 120 and the stepped surface 131 of the third metal sheet 130 overlap the bent portion 113 in a predetermined area and are not joined to the first metal sheet 110 , but are not joined. It includes regions 121b and 131b. The non-bonding regions 121b and 131b are for preventing wrinkles in the bent portion. If there are no non-bonding regions 121b and 131b for reinforcing the rear surface of the bent part 113, wrinkles of the bent part 113 may occur due to repeated bending, and the portion corresponding to the non-bonding region 121b, 131b is the bent part ( 113), the bendability of the bent portion 113 is reduced.

A thin film for bonding the second metal sheet 120 to one side supporting part 111 of the first metal sheet 110 and bonding the third metal sheet 130 to the other supporting part 112 of the second metal sheet 120 . A filler layer 140 is included. The thin film filler layer 140 is disposed on one side support part 111 and the other side support part 112 of the first metal sheet 110 and is disposed on the one side support part 111 of the first metal sheet 110 by the second metal sheet 120 . is brazed, and the third metal sheet 130 is brazed to the other side support 112 of the first metal sheet 110 .

The thin film filler layer 140 may be made of an alloy material including at least one of Ag, AgCu, and AgCuTi. Ag, AgCu and AgCu alloys increase the adhesion between the SUS metal sheet and Cu metal sheet, which are dissimilar metals. In addition, Ag, AgCu, and AgCu alloys have high thermal conductivity, so heat transferred to the SUS metal sheet is transferred to the Cu metal sheet to facilitate heat dissipation.

Although the SUS metal sheet and the Cu metal sheet can be adhered with an adhesive tape instead of the thin film filler layer 140 , the adhesive tape is relatively thick compared to the thin film filler layer 140 and has poor thermal conductivity, which greatly improves heat dissipation efficiency. lower it

The folding plate 100 applied to the foldable phone should be thin, have excellent flexibility, and in particular, should have excellent strength and thermal conductivity. Therefore, the folding plate 100 applies a SUS metal sheet to secure bending repeatability and strength, and applies a Cu metal sheet to increase the heat dissipation efficiency of a display (eg, OLED), and a SUS metal sheet and a Cu metal sheet The SUS metal sheet and the Cu metal sheet are bonded to each other with the thin film filler layer 140 to increase heat dissipation efficiency through thermal conductivity of the liver.

The thickness of the thin film filler layer 140 is in the range of 1.0 μm to 10 μm. The thickness of the thin film filler layer 140 may be formed to be 1.0 μm or more and 10 μm or less, so that the thickness of the folding plate 100 can be adjusted to be thin. Preferably, the thickness of the thin film filler layer 140 is in the range of 3.0 μm to 10 μm.

The thin film filler layer 140 may be formed as a thin film having a multilayer structure. For example, the thin film filler layer 140 is a multi-layered thin film including an Ag layer and a Cu layer formed on the Ag layer, or a multi-layered thin film including an Ag layer and a Cu layer formed on the Ag layer and an Ag layer formed on the Cu layer. It may be a structural thin film. Alternatively, the thin film filler layer 140 may include, for example, 65 to 75 wt% of Ag and 35 to 25 wt% of Cu.

Alternatively, Ti may be included as a seed layer in the thin film filler layer 140 . Ti may be formed to a thickness of 0.1 μm to 0.2 μm. For example, the thin film filler layer 140 may be formed in a multilayer structure of Ti/Cu/Ag/Cu, in this case, the Ti layer is formed to a thickness of 0.1 μm to 0.2 μm, and Cu formed on the Ti layer. The layer may be formed to a thickness of 0.2 μm to 0.5 μm, an Ag layer formed on the Cu layer to a thickness of 1.5 μm, and a Cu layer formed on the Ag layer to a thickness of 1.5 μm. . The multilayer structure of the thin film filler layer 140 is formed by brazing the first metal sheet 110 and the second metal sheet 120 , and brazing the first metal sheet 110 and the third metal sheet 130 . The boundaries can be vague.

Concave grooves 122 and 132 are formed in the second metal sheet 120 and the third metal sheet 130 . The concave grooves 122 and 132 are formed by etching predetermined areas on one or both surfaces of the second metal sheet 120 and the third metal sheet 130 . The concave grooves 122 and 132 reduce the thickness and weight of the second metal sheet 120 and the third metal sheet 130 to lighten the folding plate 100 . For example, by reducing the thickness and weight of the second metal sheet 120 and the third metal sheet 130 by controlling the depth and area of the concave grooves 122 and 132 , the folding plate 100 may be reduced in weight.

In the embodiment, the recessed grooves 122 and 132 are formed on one surface of the second metal sheet 120 and the third metal sheet 130 . In addition, the concave grooves 122 and 132 are formed on the same surface as the surface on which the stepped surfaces 121 and 131 are formed in the second metal sheet 120 and the third metal sheet 130 . The width of the concave grooves 122 and 132 may be 50% or more of the width of each of the second metal sheet 120 and the third metal sheet 130, and the depth of the concave grooves 122 and 132 may be 0.05 mm to 0.25 mm.

The second metal sheet 120 and the third metal sheet 130 may have a thickness of 150 μm to 300 μm (0.15 mm to 0.3 mm), and in the embodiment, the second metal sheet 120 and the third metal sheet. For the sheet 130 , a thickness of 150 μm is used in the same manner as that of the first metal sheet 110 . In this case, the depth of the concave grooves 122 and 132 is preferably 0.05mm to 0.075mm.

The recessed grooves 122 and 132 may contribute to weight reduction of the foldable phone by reducing the weight of the second metal sheet 120 and the third metal sheet 130 to reduce the weight of the folding plate 100 . When a foldable phone is manufactured, a back plate is attached to the rear surface of the folding plate 100 for insulation and strength reinforcement. The folding plate 100 may be stably disposed on the rear surface of the display to perform a folding function of the display.

5 is a cross-sectional view showing a state in which the folding plate according to the embodiment of the present invention is bent.

4 and 5 , the stepped surface 121 of the second metal sheet 120 and the stepped surface 131 of the third metal sheet 130 are bonded surfaces 121a and 131a and non-bonding regions. (121b,131b).

In the stepped surfaces 121 and 131 , the bonding surfaces 121a and 131a are portions bonded to the support portions 111 and 112 on both sides of the first metal sheet 110 , and the non-bonding areas 121b and 131b overlap the bent portion 113 and a predetermined area. and is not joined to the first metal sheet 110 . The thin film filler layer 140 is disposed on the bonding surfaces 121a and 131a and the thin film filler layer 140 is not disposed on the non-bonding regions 121b and 131b. The bonding surfaces 121a and 131a are bonded to both sides of the first metal sheet 110 via the thin film filler layer 140 , and the non-bonding areas 121b and 131b overlap the bent portion 113 by a predetermined area to form a bent portion ( 113) is reinforced. The non-bonding regions 121b and 131b are not joined to the bent portion 113 and thus enable the bending of the bent portion 113 while reinforcing the rear surface of the bent portion 113 during the unfolding of the bent portion 113 of the bent portion 113 . Prevents wrinkles.

As shown in FIG. 5 , the non-bonding regions 121b and 131b do not affect the bending of the bent portion 113 so that the bending repeatability of the bent portion 113 is ensured, and as shown in FIG. 4 , the bent portion ( In the state in which the 113 is unfolded, the rear surface of the bent portion 113 is reinforced to prevent wrinkles of the bent portion 113 .

6 is a cross-sectional view showing a folding plate according to another embodiment of the present invention.

As shown in FIG. 6 , in the folding plate 100 ′ of another embodiment, step surfaces 111a are also formed on both side supports 111 and 112 of the first metal sheet 110 .

The folding plate 100 of the embodiment forms stepped surfaces 121 and 131 on the second metal sheet 120 and the third metal sheet 130 , and both sides of the first metal sheet 110 on a portion of the stepped surfaces 121 and 131 . It has a structure in which the support parts 111 and 112 are joined. In the case of the embodiment, the stepped surfaces 121 and 131 are formed only on the second metal sheet 120 and the third metal sheet 130 , and the stepped surfaces are not formed on both side supports 111 and 112 of the first metal sheet 110 .

However, in another embodiment, the stepped surfaces 121 and 131 are formed on the second metal sheet 120 and the third metal sheet 130 , and the stepped surfaces 111a are also formed on the support portions 111 and 112 on both sides of the first metal sheet 110 . By forming the junction structure between the stepped surface and the stepped surface can be formed. When the stepped surface and the stepped surface are joined to each other, it has the effect of reinforcing the joint strength by expanding the joint area.

When the second metal sheet 120 and the third metal sheet 130 are joined to the support portions 111 and 112 on both sides of the first metal sheet 110 in a structure of a stepped surface and a stepped surface, the bonding area is widened, which is advantageous in securing bonding strength. can The stepped surfaces 111a formed on the both side supports 111 and 112 of the first metal sheet 110 may be formed by half-etching a portion of the both side supports 111 and 112 of the first metal sheet 110 .

The method for manufacturing a folding plate according to an embodiment of the present invention includes the steps of preparing a first metal sheet 110 having support portions 111 and 112 formed on both sides and a bent portion 113 formed in the center, and stepped surfaces 121 and 131 and yaws. The steps of preparing the second metal sheet 120 and the third metal sheet 130 in which the mouth grooves 122 and 132 are formed, and the end of the one side support 111 of the first metal sheet 110 and the second metal sheet 120 . Disposing the thin film filler layer 140 between the vehicle surface 121, the other side support 112 of the first metal sheet 110 and the step surface 131 of the third metal sheet, and brazing bonding. includes

In the step of preparing the first metal sheet in which the support portions are formed on both sides and the bent portion is formed in the center, the first metal sheet 110 is prepared using a stainless steel metal sheet.

In addition, the bent portion 113 is formed in a mesh shape by photo-etching the first metal sheet 110 . If the mesh is formed by punching it with a press, it is difficult to precisely form the mesh pattern, so it is formed by photo-etching. Photo etching can precisely form a mesh pattern. The mesh is formed so that the line width is at least 0.11㎛.

In the step of preparing the second metal sheet and the third metal sheet on which the stepped surface and the concave groove are formed, the second metal sheet 120 and the third metal sheet 130 are prepared by using a metal sheet made of copper or a copper alloy material. For example, SUS 304 or SUS 316 may be prepared for the second metal sheet 120 and the third metal sheet 130 .

In addition, the stepped surfaces 121 and 131 and the concave grooves 122 and 132 are formed by half-etching the second metal sheet 120 and the third metal sheet 130 . When the stepped surfaces 121 and 131 are formed by punching with a press, the flatness is lowered and the bonding strength is lowered. Therefore, they are formed by half-etching. Etching contributes to increasing the bonding strength by improving the flatness. The recessed grooves 122 and 132 are precisely formed by half-etching for heat dissipation and weight reduction. The stepped surfaces 121 and 131 and the concave grooves 122 and 132 may be simultaneously formed by one half-etching. The half etching for forming the stepped surfaces 121 and 131 and the concave grooves 122 and 132 may be performed in a range of 0.05 mm to 0.25 mm.

The step of disposing the thin film filler layer between the one side support of the first metal sheet and the stepped surface of the second metal sheet, and the other support of the first metal sheet and the stepped surface of the third metal sheet, includes applying a paste, a foil ( foil) and arrange a thin-film filler layer having a thickness of 1.0 µm or more and 10 µm or less by either method of P-filer. The thin film filler layer 140 may have a three-layer structure of Ti layer/Cu layer/Ag layer and a four-layer structure of Ti layer/Cu layer/Ag layer/Cu layer.

The step of disposing the thin film filler layer between the one side support of the first metal sheet and the stepped surface of the second metal sheet and the other support of the first metal sheet and the stepped surface of the third metal sheet comprises: a second metal sheet ( Among the stepped surface 121 of 120 and the stepped surface 131 of the third metal sheet 130 , the bonding surfaces 121a and 131a in contact with the one side support part 111 and the other side support part 112 of the first metal sheet 110 . ), the thin film filler layer 140 is disposed.

The thin film filler layer 140 is not disposed in a region overlapping the bent portion 113 by a predetermined region on the stepped surface 121 of the second metal sheet 120 and the stepped surface 131 of the third metal sheet 130 .

In the brazing bonding step, between the one side support part 111 of the first metal sheet 110 and the stepped surface 121 of the second metal sheet 120 , the other side support part 112 of the first metal sheet 110 and The thin film filler layer 140 disposed between the stepped surfaces 131 of the third metal sheet 130 is melted with high-temperature heat to bond the Cu metal sheet and the SUS metal sheet, which are dissimilar metals.

Brazing bonding enables bonding of Cu (or Cu alloy) metal sheets, which are dissimilar metals, and SUS metal sheets. The step of brazing bonding is carried out at 780-900° C., and performing upper weight or pressure during brazing bonding. Applying top weight or pressing during brazing is for void-free bonding.

The brazing furnace is efficient by controlling the heating temperature in the brazing furnace to 780° C. or higher, preferably in the range of 780 to 900° C. Allow the brazing bonding process to take place.

The folding plates 100 and 100 ′ manufactured according to an embodiment of the present invention are formed in the same plane and have a thickness of 150 μm to 300 μm (0.15 mm to 0.3 mm).

When the thickness of the first metal sheet 110, the second metal sheet 120, and the third metal sheet 130 is 150 μm, the thickness of the step surfaces 121 and 131 formed by half etching and the depth of the concave grooves 122 and 132 may be 75 μm (0.075 mm).

In the above-described folding plates 100 and 100 ′, the first metal sheet 110 is formed of a rigid stainless material, and the bent portion 113 formed on the first metal sheet 110 has a folding function.

In addition, in the folding plates 100 and 100 ′, the second metal sheet 120 and the third metal sheet 130 formed of copper or copper alloy material have a heat dissipation effect, and the second metal sheet on both sides of the first metal sheet 110 . The thin film filler layer 140 bonded to the sheet 120 and the third metal sheet 130 rapidly heats the heat of the first metal sheet 110 to the second metal sheet 120 and the third metal sheet 130 . Because it transmits, it has excellent heat dissipation properties.

In addition, in the folding plates 100 and 100 ′, the concave grooves 122 and 132 formed in the second metal sheet 120 and the third metal sheet 130 contribute to weight reduction.

In addition, in the folding plates 100 and 100 ′, the non-bonding regions 121b and 131b of the second metal sheet 120 and the third metal sheet 130 extending toward the rear surface of the bent portion 113 are the rear surfaces of the bent portion 113 . to increase the bending repeatability and prevent wrinkles of the bent portion 113 . Accordingly, the folding plates 100 and 100 ′ can be perfectly folded even when folded over tens of thousands of repeated bending and become a flat flat surface without any traces of folding when unfolded.

The above-described folding plates 100 and 100 ′ are easy to apply to foldable phones that require heat dissipation, light weight, and anti-wrinkle at the bent part, so that bending repeatability is required, heat dissipation is high, and weight reduction is required.

The above-described folding plate may be applied to a foldable phone having a triple display in which three screens are folded in the form of a folding screen, an out-folding type foldable phone, and an in-folding type foldable phone to support the display.

BRIEF DESCRIPTION OF THE DRAWINGS The present invention is disclosed in the drawings and in the specification with preferred embodiments. Here, although specific terms have been used, they are used only for the purpose of describing the present invention and are not used to limit the meaning or scope of the present invention described in the claims. Therefore, it will be understood by those skilled in the art that various modifications and equivalent other embodiments of the present invention are possible therefrom. Accordingly, the true technical scope of the present invention should be defined by the technical spirit of the appended claims.

10: foldable phone 11: display
13: secondary display 100: folding plate
110: first metal sheet 111, 112: support part
113: bent portion 120: second metal sheet
121; Step surface 121a: joint surface
121b: non-junction area 122: concave groove
130: third metal sheet 131: stepped surface
131a: bonding surface 131b: non-bonding area
132: concave groove 140: thin film filler layer

Claims (17)

a first metal sheet having support portions formed on both sides and bent portions formed in the center;
a second metal sheet joined to one side support of the first metal sheet;
a third metal sheet joined to the other support portion of the first metal sheet; and
a thin film filler layer disposed on one side support portion and the other side support portion of the first metal sheet for brazing bonding the first metal sheet and the second metal sheet, and brazing bonding the first metal sheet and the third metal sheet;
A folding plate comprising a. The method of claim 1,
The thin-film filler layer is a folding plate made of an alloy material containing at least one of Ag, AgCu, AgCuTi. The method of claim 1,
The thickness of the thin-film filler layer is in the range of 1.0㎛ ~ 10㎛ folding plate. The method of claim 1,
The first metal sheet is formed of a stainless (SUS) material,
A folding plate in which the second metal sheet and the third metal sheet are formed of copper or a copper alloy material. The method of claim 1,
A folding plate in which a bonding surface of a second metal sheet bonded to one support portion of the first metal sheet and a bonding surface of a third metal sheet bonded to the other support portion of the first metal sheet are stepped surfaces. 6. The method of claim 5,
The step surface of the second metal sheet and the step surface of the third metal sheet overlap the bent portion by a predetermined area and include a non-bonding area that is not joined to the first metal sheet. The method of claim 1,
A folding plate in which the first metal sheet, the second metal sheet, and the third metal sheet form the same plane. The method of claim 1,
A folding plate in which the bent portion is formed of a mesh and the support portion is formed of a flat plate. 9. The method of claim 8,
The mesh is a folding plate having a line width of at least 0.11 μm. The method of claim 1,
The second metal sheet and the third metal sheet may include a recessed groove etched in a predetermined region. 11. The method of claim 10,
The depth of the concave groove is a folding plate of 0.05mm to 0.25mm. Preparing a first metal sheet in which support portions are formed on both sides and a bent portion is formed in the center;
preparing a second metal sheet and a third metal sheet having stepped surfaces and concave grooves formed thereon;
disposing a thin film filler layer between the one side support part of the first metal sheet and the stepped surface of the second metal sheet, and between the other support part of the first metal sheet and the stepped surface of the third metal sheet; and
brazing bonding;
A method of manufacturing a folding plate comprising a. 13. The method of claim 12,
In the step of preparing a first metal sheet in which support portions are formed on both sides and a bent portion is formed in the center,
A method for manufacturing a folding plate wherein the bent portion is formed in a mesh shape by photo-etching the first metal sheet. 13. The method of claim 12,
In the step of preparing the second metal sheet and the third metal sheet in which the stepped surface and the concave groove are formed,
The step surface and the concave groove are formed by half-etching the second metal sheet and the third metal sheet. 13. The method of claim 12,
In the step of disposing a thin film filler layer between the step surface of the second metal sheet and the one side support of the first metal sheet, between the other side support of the first metal sheet and the step surface of the third metal sheet,
A method for manufacturing a folding plate in which a thin-film filler layer having a thickness of 1.0 μm or more and 10 μm or less is disposed by any one of paste application, foil attachment, and P-filer. 13. The method of claim 12,
In the step of disposing a thin film filler layer between the step surface of the second metal sheet and the one side support of the first metal sheet, between the other side support of the first metal sheet and the step surface of the third metal sheet,
The stepped surface of the second metal sheet and the stepped surface of the third metal sheet overlap the bent portion by a predetermined region, and the stepped surface of the second metal sheet and the stepped surface of the third metal sheet overlap the bent portion. A method for manufacturing a folding plate in which a thin-film filler layer is not disposed. 13. The method of claim 12,
The brazing bonding step is,
A method of manufacturing a power module that is performed at 780-900° C. and performs upper weight or pressurization during brazing bonding.

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