KR20220090703A - Folding plate and manufacturing method thereof - Google Patents

Abstract

The present invention relates to a folding plate and a method for manufacturing the same, comprising: a first metal sheet having a folding part to be folded, a second metal sheet and a third metal sheet joined to both sides of the first metal sheet, and the second metal sheet; and a magnetic shield bonded to a predetermined region of the third metal sheet. The folding plate according to the present invention may be applied to a foldable phone to support the display, and may have a magnetic shielding effect.

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.

In foldable phones, magnets are placed on both edges to close the liquid crystal frame, but due to the magnetism of these magnets, there is a problem in that an error occurs in the recognition of liquid crystal input when using the electronic pen or an error such as frequency shift occurs.

It is an object of the present invention to provide a folding plate having a magnetic shielding effect by having a magnetic shielding unit to prevent errors such as liquid crystal input recognition and frequency displacement due to a magnet used to open and close a foldable phone, and a method for manufacturing the same.

In addition, the present invention has a heat dissipation function and a support function of a display through dissimilar metal bonding of a metal sheet with excellent bending repeatability and a metal sheet with excellent heat dissipation properties, and provides a folding plate with excellent flexibility and excellent durability, and a method for manufacturing the same will provide

According to a feature of the present invention for achieving the object as described above, the present invention provides a first metal sheet having a folding part formed therein, a second metal sheet and a third metal sheet joined to both sides of the first metal sheet, The second metal sheet and the third metal sheet may include a magnetic shield bonded to a predetermined region.

The magnetic shielding unit may be made of a metal material different from that of the second metal sheet and the third metal sheet.

The second metal sheet and the third metal sheet may be made of copper, and the magnetic shield may be made of a cold rolled steel sheet.

The predetermined region includes a hole formed through the second metal sheet and the third metal sheet, and a bonding area formed at the edge of the hole, the magnetic shielding part is disposed in the hole, and the bonding part formed at the edge of the magnetic shielding part is bonded to the bonding area. can

The junction region and the junction portion may be a stepped surface.

The second metal sheet, the third metal sheet, and the magnetic shielding portion may have upper surfaces that are coplanar with each other, and lower surfaces of the second metal sheet that may form the same plane with each other.

In addition, the folding plate may further include a brazing filler, and the brazing filler may bond the magnetic shielding portion to a predetermined region of the second metal sheet and the third metal sheet.

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

In a state where the second metal sheet and the third metal sheet face each other, the magnetic shielding unit bonded to the second metal sheet and the magnetic shielding unit bonded to the third metal sheet may be disposed at positions facing each other.

The first metal sheet has first and second support portions formed on both sides thereof, a folding portion is formed in the center, the second metal sheet is bonded to the lower surface of the first support portion, and the third metal sheet is formed on the lower surface of the second support portion. are bonded, the second metal sheet, the third metal sheet, and the magnetic shielding portion may form a coplanar top surface with each other.

The method for manufacturing a folding plate according to the present embodiment includes the steps of preparing a first metal sheet having a folding part to be folded, preparing a second metal sheet and a third metal sheet having a predetermined region, the second metal sheet and the second metal sheet 3 It may include bonding the magnetic shielding portion to a predetermined region of the metal sheet, and bonding the second metal sheet and the third metal sheet to both sides of the first metal sheet.

The predetermined region includes a hole formed through the second metal sheet and the third metal sheet, and a bonding area formed at the edge of the hole, the magnetic shielding part is disposed in the hole, and the bonding part formed at the edge of the magnetic shielding part is bonded to the bonding area. can

The magnetic shielding part may form a junction part corresponding to the junction area of a predetermined area by half-etching the edge.

The steps of preparing the second metal sheet and the third metal sheet include the steps of forming a hole by penetrating the second metal sheet and the third metal sheet in the thickness direction, and half-etching the peripheral area of the hole to form a stepped junction area. It may include the step of forming.

On the other hand, the step of preparing the second metal sheet and the third metal sheet includes the steps of half-etching the second metal sheet and the third metal sheet in the thickness direction to form a stepped junction region, and a central portion of the junction region. It may include the step of through-etching to form the hole.

The step of bonding the magnetic shielding part may include disposing a brazing filler between the bonding area of the second metal sheet and the magnetic shielding part and between the bonding area of the third metal sheet and the magnetic shielding part, and brazing bonding. have.

In the step of disposing the brazing filler, a brazing filler having a thickness of 1.0 μm or more and 10 μm or less may be disposed by any one of sputtering, paste application, foil attachment, and P-filler.

In addition, between the bonding of the magnetic shielding part and the bonding of the second metal sheet and the third metal sheet, hot press forming or cold press forming of the second metal sheet and the third metal sheet to which the magnetic shielding part is bonded; may further include.

In the present invention, the second and third metal sheets made of copper are joined to the first and second support portions of the first metal sheet made of stainless material to have a heat dissipation effect, and a cold rolled steel sheet material similar to the thermal expansion coefficient of copper material. A folding plate having a magnetic shielding function may be manufactured by brazing the magnetic shielding portion to the second and third metal sheets.

In addition, the present invention can be manufactured in the form of an integrated thin film sheet having a thin thickness by forming a stepped surface through half-etching and bonding the magnetic shielding part to the second and third metal sheets.

In addition, according to the present invention, the second and third metal sheets made of a copper alloy material having a thin film, high strength and high heat dissipation function and the first metal sheet made of stainless steel having excellent bending repeatability can be manufactured thinly through brazing using a thin film filler layer. , it is possible to manufacture a folding plate that is light, strong, and particularly easy to heat diffusion.

1 is a diagram illustrating an in-folding type foldable phone in which a display screen of a mobile terminal is folded inward around a vertical axis as an example of a foldable phone.
2 is a plan view illustrating a folding plate according to an embodiment of the present invention.
3 is a plan view showing an exploded folding plate according to an embodiment of the present invention.
4 is a cross-sectional view illustrating a folding plate according to an embodiment of the present invention.
5 is an exploded cross-sectional view illustrating a folding plate according to an embodiment of the present invention.
6 is a cross-sectional view illustrating a state in which the folding plate of FIG. 4 is folded.
7 is a cross-sectional view illustrating a modified example of a folding plate according to an embodiment of the present invention.
8 is an exploded cross-sectional view illustrating a modified example of a folding plate according to an embodiment of the present invention.
9 is a flowchart illustrating a method for manufacturing a folding plate according to an embodiment of the present invention.
10 is a flowchart illustrating the steps of preparing a second metal sheet and a third metal sheet in a method for manufacturing a folding plate according to an embodiment of the present invention.
11 is a flowchart illustrating another example of a step of preparing a second metal sheet and a third metal sheet in a method for manufacturing a folding plate according to an embodiment of the present invention.
12 is a flowchart illustrating a step of bonding a magnetic shield in a method for manufacturing a folding plate according to an 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, which is a mobile terminal of a folding type in which a display is folded. 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.

1 is a diagram illustrating an in-folding type foldable phone in which a display screen of a mobile terminal is folded inward around a vertical axis as an example of a foldable phone, and FIG. 2 is a plan view illustrating a folding plate according to an embodiment of the present invention. 3 is a plan view showing an exploded folding plate according to an embodiment of the present invention.

As shown in FIG. 1 , the foldable phone 10 is an in-folding method in which the left and right sides of the display 11 are folded inward around a vertical axis (a), and the foldable phone 10 is an auxiliary shown in a folded state. A display 12 may be provided. The display 11 may be an OLED.

The foldable phone 10 arranges a folding plate 100 (refer to FIG. 2 ) on the back of the display 11 so that the folding part is completely folded when folded, and when unfolded, the display 11 screen is supported so that the screen is not wrinkled and flat during use. to be able to keep the In addition, the folding plate 100 may be formed of a material having excellent thermal conductivity to dissipate heat generated from the display 11 .

The foldable phone 10 may include a first magnet 13a and a second magnet 13b therein. Here, the first magnet 13a and the second magnet 13b may be disposed at positions facing each other when the foldable phone 10 is folded. The folded state of the foldable phone 10 may be maintained by an attractive force between the first magnet 13a and the second magnet 13b. That is, the attractive force between the first magnet 13a and the second magnet 13b corresponds to the elasticity of the folding plate 100 (the restoring force to be unfolded when the folding part 113 of the first metal sheet 110 is folded). This can be maintained in a folded state.

The magnetic fields from the first magnet 13a and the second magnet 13b may cause an error when inputting through an electronic pen (not shown). For example, when the display 11 screen is input (touch input or hovering input) using an electronic pen utilizing an electromagnetic field in a state in which the display 11 is unfolded, the first and second magnets 13a, The magnetic field from 13b) may cause errors such as liquid crystal input recognition or frequency shift.

1 to 3, the folding plate 100 according to the embodiment of the present invention is provided with a magnetic shielding unit 140, so that the magnetic fields of the first and second magnets 13a and 13b are displayed ( 11) and reduce the impact on the interaction between the electronic pen. That is, the folding plate 100 is disposed between the rear surface of the display 11 and the upper surfaces of the first and second magnets 13a and 13b so that the magnetic fields from the first and second magnets 13a and 13b are generated by the display 11 . ) can be reduced. The first and second magnets 13a and 13b may be bonded to a lower portion of the folding plate 100 through a laminating process, and a display 11 may be bonded to an upper portion of the folding plate 100 .

In addition, in the folding plate 100 of the present invention, the magnetic shielding unit 140 is brazed to the regions corresponding to the first and second magnets 13a and 13b in the second and third metal sheets 120 and 130 made of copper. Therefore, it is possible to manufacture in a thin thickness, and to increase the magnetic shielding effect, and it is possible to efficiently dissipate heat generated by the display 11 .

The folding plate 100 according to the embodiment of the present invention will be described by taking as an example a shape applied to an in-folding type foldable phone that is folded inward around the vertical axis (a) shown in FIG. 1 . However, the present invention is not limited thereto, and it may be applied to a flip phone of a clam shell type that is folded in the width direction.

4 is a cross-sectional view illustrating a folding plate according to an embodiment of the present invention, FIG. 5 is an exploded cross-sectional view illustrating a folding plate according to an embodiment of the present invention, and FIG. 6 is a state in which the folding plate of FIG. 4 is folded. is a cross-sectional view showing

4 to 6 , the folding plate 100 according to an embodiment of the present invention includes a first metal sheet 110 , a second metal sheet 120 , a third metal sheet 130 , and a magnetic field. A shielding unit 140 may be included. The folding plate 100 may have a shape in which the first metal sheet 110 connects between the second metal sheet 130 and the third metal sheet 130 . In this case, upper surfaces of the first metal sheet 110 , the second metal sheet 120 , and the third metal sheet 130 may form the same plane.

The first metal sheet 110 is to perform a supporting function and a folding function of the display 11, and first and second supporting parts 111 and 112 for maintaining the screen of the display 11 flat are provided on both sides. The folding part 113 may be formed in the center of the first and second support parts 111 and 112 . The first and second support parts 111 and 112 may be formed of a flat plate, and the folding part 113 may be formed of a mesh.

According to this embodiment, the first metal sheet 110 may be formed of a material having a rigidity so that the display 11 is not wrinkled. However, since the rigid material is difficult to fold in the folding part 113, the central portion of the rigid material is formed as a mesh to function as a spring. The first metal sheet 110 is completely folded by the folding part 113 formed of a mesh, and when unfolded, sagging or wrinkling of the display 11 can be prevented by the first and second support parts 111 and 112 .

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

The mesh-shaped folding part 113 may be formed by photo-etching the central portion of the first metal sheet 110 . However, the present invention is not limited thereto and various processes for forming the mesh may be used. However, if the mesh is formed by punching it with a press, the mesh pattern may not be precise, and if the mesh pattern is not precise, it is difficult to form the folding part 113 having the desired elasticity, so a process such as press punching is not used. it is preferable

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. As an example of the amorphous alloy, iron-based amorphous may be used. According to this embodiment, the first metal sheet 110 may form the folding part 113 through photo-etching. In this case, the first metal sheet 110 is preferably made of a stainless material. This is because amorphous has rigidity but poor etching properties, whereas stainless steel has good etching properties while being rigid.

As an example of the stainless material, SUS 304 and SUS 316 may be used. 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 have a thickness of 150 μm to 300 μm, and in the embodiment, SUS 304 or SUS 316 uses a thickness of 150 μm for weight reduction. At this time, when the mesh pattern forming the folding part 113 is precisely formed, flexibility is improved, and it is preferable to provide a line width of about 0.110 μm to have excellent bending function and elastic restoring force.

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

The second metal sheet 120 and the third metal sheet 130 are formed of a metal material having a heat dissipation function, and an adhesive material having thermal conductivity with the first and second support parts 111 and 112 of the first metal sheet 110 . It is bonded to the phosphorous thin film filler layer 150 to emit heat generated in the display 11 . The second metal sheet 120 and the third metal sheet 130 may be formed of copper or a copper alloy material. Here, the second metal sheet 120 and the third metal sheet 130 have high strength and high strength to further reinforce the strength of the first metal sheet 110 made of stainless steel as well as the heat dissipation function of the first metal sheet 110 . It may be formed of a copper alloy material having a function of high heat dissipation.

As an example, the copper alloy material may be one of C7025, C7035, and PH-1000HS Series. C7025, C7035, PH-1000HS have a tensile strength of 900 MPa or more, a thermal conductivity of 170 W/m.K, high strength and high heat dissipation.

C7025, C7035, and PH-1000HS can be used with a thickness of 50㎛ ~ 150㎛, in the embodiment, C7025, C7035, PH-1000HS has a thickness of 80㎛ (0.08mm) in consideration of both the thin thickness and heat dissipation efficiency that can be used

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 bonding surface 121a of the second metal sheet 120 that is bonded to the first support 111 of the first metal sheet 110 and the second support 112 of the first metal sheet 110 are bonded to each other. The bonding surface 131a of the third metal sheet 130 to be used 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 folding part 113 by a predetermined area and are not bonded to the first metal sheet 110 . and bonding regions 121b and 131b. The non-bonding regions 121b and 131b are for preventing wrinkles of the folding part 113 . If there are no non-bonding regions 121b and 131b for reinforcing the rear surface of the folding part 113, wrinkles of the folding part 113 may occur due to repeated bending, and the portion corresponding to the non-bonding regions 121b and 131b may be When joined to the folding part 113 , the bendability of the folding part 113 may be deteriorated.

The thin film filler layer 150 is formed by brazing bonding the first support part 111 and the second metal sheet 120 of the first metal sheet 110 , and the second support part 112 and the second support part 112 of the first metal sheet 110 . 3 The metal sheet 130 can be brazed.

The thin film filler layer 150 may be made of an alloy material including at least one of Ag, AgCu, and AgCuTi. The Ag, AgCu, and AgCu alloy may increase bonding strength between the first metal sheet 110 made of a stainless material, which is a dissimilar metal, and the second and third metal sheets 120 and 130 made of a copper material. As such, when the thin film filler layer 150 is formed of an alloy of Ag, AgCu and AgCu having higher thermal conductivity than the first metal sheet 110 made of a stainless material, it is generated in the display 11 provided with an OLED and the first metal sheet ( The heat transferred to 110) may be smoothly transferred to the second and third metal sheets 120 and 130 made of copper to facilitate heat dissipation.

According to the present embodiment, the thickness of the thin film filler layer 150 may be formed in a range of 1.0 μm to 10 μm. Preferably, the thickness of the thin film filler layer 150 is preferably formed in a range of 3.0 μm to 10 μm.

The thin film filler layer 150 may be formed as a thin film having a multilayer structure. For example, the thin film filler layer 150 is a multi-layered thin film including an Ag layer and a Cu layer formed on the Ag layer, or a multilayer 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 150 may include, for example, 65 to 75 wt% of Ag and 35 to 25 wt% of Cu.

In addition, the thin film filler layer 150 may include Ti as a seed layer. Ti may be formed to a thickness of 0.1 μm to 0.2 μm. For example, the thin film filler layer 150 may be formed in a multilayer structure of Ti/Cu/Ag/Cu. At this time, the Ti layer is formed to a thickness of 0.1 μm to 0.2 μm, the Cu layer formed on the Ti layer is formed to a thickness of 0.2 μm to 0.5 μm, and the Ag layer formed on the Cu layer is formed to have a thickness of 1.5 μm. It may be formed to a thickness of 1.5 μm, and a Cu layer formed on the Ag layer may be formed to a thickness of 1.5 μm. The multilayer structure of the thin film filler layer 150 may have ambiguous boundaries after brazing bonding.

The magnetic shielding unit 140 is provided to reduce the effect of the magnetic field on the display 11 by blocking the magnetic force generated from the first and second magnets 13a and 13b shown in FIG. 1 from being directed to the display 11 . can be The magnetic shielding unit 140 may be bonded to predetermined regions 122 and 132 of the second metal sheet 120 and the third metal sheet 130 . The predetermined regions 122 and 132 of the second metal sheet 120 and the third metal sheet 130 may include holes 122a and 132a and bonding regions 122b and 132b formed at edges of the holes 122a and 132a. can The holes 122a and 132a may be formed by penetrating the second metal sheet 120 and the third metal sheet 130 in the thickness direction, and the bonding regions 122b and 132b are formed in the second and third metal sheets ( It may be a stepped surface formed by half-etching the peripheral regions of the holes 122a and 132a in 120 and 130 . On the other hand, the second metal sheet 120 and the third metal sheet 130 are half-etched in the thickness direction to form stepped junction regions 122b and 132b, and penetrate the central portion of the junction regions 122b and 132b. Holes 122a and 132a may be formed by etching. Regardless of the etching order, the junction regions 122b and 132b may be formed as a stepped surface to be bonded to the junction 142 , which is a stepped surface of the magnetic shielding unit 140 .

The insertion part 142 formed in the center of the magnetic shielding part 140 may be disposed in the holes 122a and 132a of the second and third metal sheets 120 and 130 . As described above, since the magnetic shielding unit 140 is provided in a shape corresponding to the predetermined regions 122 and 132 and is inserted into and bonded to the predetermined regions 122 and 132, it can be manufactured in the form of one integrated thin film sheet.

The thickness of the second metal sheet 120 and the third metal sheet 130 and the thickness of the magnetic shielding part 140 may be formed to be the same as 80 μm (0.08 mm). In addition, the thickness of the portion where the bonding regions 122b and 132b is formed and the thickness of the portion where the bonding portion 142 is formed may be 40 μm (0.04 mm), which is a thickness obtained by half-etching the thickness of 80 μm (0.08 mm).

That is, when the bonding portion 142 of the magnetic shielding unit 140 is bonded to the bonding regions 122b and 132b of the second and third metal sheets 120 and 130 , the thickness of the bonding portion is the second and third metal sheets 120 and 130 . ) equal to the thickness of In other words, the upper surfaces of the second metal sheet 120 , the third metal sheet 130 , and the magnetic shielding unit 140 may form the same plane as each other, and the respective lower surfaces may also form the same plane with each other.

Meanwhile, although FIGS. 4 and 5 show an example in which the width of the upper surface of the magnetic shielding unit 140 is wider than the width of the lower surface, it is not limited thereto, and the width of the lower surface is wider than the width of the upper surface. may be provided. As an example, the width of the magnetic shielding unit 140 may be 7 mm, the length may be 60 mm, and the thickness may be 80 μm (0.08 mm). In addition, the magnetic shielding unit 140 may be bonded at a distance of 4.0 mm from the edges of the second and third metal sheets 120 and 130 .

The magnetic shielding unit 140 is preferably made of a cold rolled steel plate (SPCC: Steel Plate Cold Commercial) material. Since the coefficient of thermal expansion of the cold-rolled steel sheet is 17.3 ppm/K, it is similar to the coefficient of thermal expansion of copper, which is a material of the second and third metal sheets 120 and 130, of 17 ppm/K, so that deformation can be minimized. If the difference between the thermal expansion coefficient of the magnetic shielding unit 140 and the thermal expansion coefficient of the second and third metal sheets 120 and 130 is large, waving or warping may occur during the brazing bonding process. That is, when the brazing bonding process is carried out at a high temperature of about 780 to 900 ° C, the magnetic shielding unit 140 and the second and third metal sheets 120 and 130 are made of different materials, so a difference occurs during expansion and contraction due to heat. , this difference may cause waving or warping. As such, when defects such as waving or bending occur in the folding plate 100 to cause a problem in flatness, it can be transferred to the display 11 disposed on the upper side as it is. Accordingly, it is preferable that the material of the magnetic shielding unit 140 has a magnetic shielding function and a thermal expansion coefficient similar to that of the second and third metal sheets 120 and 130 .

As shown in FIGS. 4 and 5 , in the magnetic shielding part 140 , the insertion part 141 is disposed in the holes 122a and 132a of the second and third metal sheets 120 and 130 , and the junction part 142 is formed. It is seated in the bonding regions 122b and 132b and may be brazed through the brazing pillar 160 . The brazing filler 160 may be made of an alloy material including at least one of Ag, AgCu, and AgCuTi. Ag, AgCu, and AgCu alloys may increase bonding strength between the second and third metal sheets 120 and 130 made of copper, which is a dissimilar metal, and the magnetic shielding unit 140 made of, a cold rolled steel sheet.

According to this embodiment, the thickness of the brazing filler 160 may be formed in the range of 1.0㎛ ~ 10㎛. Preferably, the thickness of the brazing filler 160 is preferably formed in the range of 3.0㎛ ~ 10㎛.

When the second and third metal sheets 120 and 130 and the magnetic shielding unit 140 are attached with an adhesive tape, an adhesive, etc., the heat dissipation adhesive is expensive, so there is a problem in that it becomes a burden in terms of cost. On the other hand, the present invention has an advantage in that the magnetic shielding unit 140 can be hermetically bonded to the predetermined regions 122 and 132 of the second and third metal sheets 120 and 130 using a relatively inexpensive brazing filler 160 . In addition, since brazing is joined by applying heat as much as the base material is not damaged, it has the advantage of excellent bonding strength while minimizing damage.

Referring to FIG. 3 , when viewed in a plan view, the bonding portion 142 of the magnetic shielding unit 140 may be formed in a rectangular shape surrounding the insertion portion 141 . At this time, although not shown, the brazing filler 160 may be disposed on the entirety of the junction portion 142 in the square shape, or may be disposed only partially at a predetermined interval. In the process of brazing the magnetic shielding unit 140 and the second and third metal sheets 120 and 130 together, waving or bending may occur due to a difference between expansion and contraction due to heat. Therefore, when the brazing filler 160 is not disposed on the entire surface of the joint portion 142, but only partially, during brazing, deformation such as waving or bending can be minimized. For example, the brazing filler 160 may be disposed on a surface corresponding to half of the entire surface of the bonding portion 142 .

As shown in FIG. 6 , in a state where the second metal sheet 120 and the third metal sheet 130 face each other, the magnetic shielding unit 140 bonded to the second metal sheet 120 and the third metal sheet ( The magnetic shielding unit 140 bonded to 130 may be disposed at positions facing each other. When the foldable phone 10 is in the folded state, the first magnet 13a and the second magnet 13b are disposed at positions opposite to each other so that attractive forces act, and corresponding to the first and second magnets 13a and 13b The magnetic shielding unit 140 is disposed at the position. Accordingly, when the folding plate 100 is folded around the folding part 113 so that the second metal sheet 120 and the third metal sheet 130 face each other, the second and third metal sheets 120 and 130 are respectively attached to each other. The bonded magnetic shielding units 140 may be disposed at positions facing each other.

7 is a cross-sectional view illustrating a modified example of a folding plate according to an embodiment of the present invention, and FIG. 8 is an exploded cross-sectional view illustrating a modified example of the folding plate according to an embodiment of the present invention.

7 and 8, the folding plate 100' has first and second support parts 111' and 112' formed on both sides of the first metal sheet and the folding part 113' is formed in the center. (110'), a second metal sheet 120' joined to the lower surface of the first support part 111', and a third metal sheet 130' joined to the lower surface of the second support part 112', and a second 3 It may include a magnetic shielding unit 140' bonded to the predetermined regions 122' and 132' of the metal sheet 130'.

Here, the upper surfaces 121' and 131' of the second metal sheet 120' and the third metal sheet 130' are formed with a thin film filler layer 150' on the first and second support parts 111' and 112'. The bonding surfaces 121'a and 131'a, which are brazed through the medium, and the non-bonding area 121'b that is not bonded to the first metal sheet 110' while overlapping the folding part 113' by a predetermined area; 131'b).

The insertion part 141' of the magnetic shielding part 140' is disposed in the holes 122'a and 132'a of the second and third metal sheets 120' and 130', and the junction part 142' is formed. It is seated in the bonding regions 122'b and 132'b, and may be brazed through the brazing pillar 160'.

As such, in the folding plate 100', the magnetic shielding unit 140' is bonded to the predetermined regions 122' and 132' of the second metal sheet 120' and the third metal sheet 130', and the bonding is performed. Afterwards, the second metal sheet 120 , the third metal sheet 130 , and the magnetic shielding unit 140 may have upper surfaces that are coplanar with each other. Accordingly, the second and third metal sheets 120' and 130' prevent waving or bending when bonded to both sides of the lower surface of the first metal sheet 110', that is, the first and second support parts 111' and 112'. It can be brazed without generating.

9 is a flowchart illustrating a method for manufacturing a folding plate according to an embodiment of the present invention.

As shown in FIG. 9, the method for manufacturing a folding plate according to an embodiment of the present invention includes a step (S10) of preparing the first metal sheet 110 on which a folding part 113 is formed, and predetermined regions 122 and 132. A step (S20) of preparing the formed second metal sheet 120 and the third metal sheet 130, and magnetic shielding in predetermined regions 122 and 132 of the second metal sheet 120 and the third metal sheet 130 The step of bonding the part 140 (S30) and the step of bonding the second metal sheet 120 and the third metal sheet 130 to both sides of the first metal sheet 110 (S40) are included.

In the step (S10) of preparing the first metal sheet 110 on which the folding part 113 is formed to be folded, the first metal sheet 110 has a first support part 111 and a second support part 112 formed on both sides thereof. The folding part 113 may be formed into a mesh by photo-etching the central portion of the first metal sheet 110 . The first metal sheet 110 is a stainless material sheet. For example, the first metal sheet 110 may be made of SUS304 or SUS316 having a thickness of 0.15 mm.

In the step of preparing the second metal sheet 120 and the third metal sheet 130 on which the predetermined regions 122 and 132 are formed ( S20 ), the predetermined regions 122 and 132 include holes 122a and 132a and the holes 122a and 132a. ) may include bonding regions 122b and 132b formed on the edges.

In addition, in the step of preparing the second metal sheet 120 and the third metal sheet 130 ( S20 ), the thickness of the second metal sheet 120 and the third metal sheet 130 is formed as shown in FIG. 10 . A step (S21) of forming the holes (122a, 132a) by etching through the direction (S21), and a step (S22) of forming stepped junction regions (122b, 132b) by half-etching the peripheral regions of the holes (122a, 132a) (S22) may include

On the other hand, in the step (S20) of preparing the second metal sheet 120 and the third metal sheet 130, the thickness of the second metal sheet 120 and the third metal sheet 130 is formed as shown in FIG. Forming stepped junction regions 122b and 132b by half-etching in the direction (S21'), and forming holes 122a and 132a by etching through a central portion of the junction regions 122b and 132b (S21'). S22') may be included.

Here, the thickness of the second metal sheet 120 and the third metal sheet 130 may be 80 μm (0.08 mm), and in the half etching, the bonding regions 122b and 132b have a thickness of 40 μm (0.04 mm). It can be done to have The processing precision during half etching may have a tolerance of 15 μm to a thickness of 40 μm.

In the step (S30) of bonding the magnetic shielding part 140 to the predetermined regions 122 and 132 of the second metal sheet 120 and the third metal sheet 130, the magnetic shielding part 140 is formed by half-etching the edges. A bonding portion 142 corresponding to the stepped bonding areas 122b and 132b of the second and third metal sheets 120 and 130 may be formed. The thickness of the magnetic shielding part 140 may be 80 µm (0.08 mm), and the half etching may be performed so that the junction part 142 has a thickness of 40 µm (0.04 mm). The processing precision during half etching may have a tolerance of 15 μm to a thickness of 40 μm.

In this way, when the bonding regions 122b and 132b of the second and third metal sheets 120 and 130 and the bonding portion 142 of the magnetic shielding portion 140 are half-etched and bonded, the thickness of the bonding portion is the second and third It is the same as the thickness of the metal sheets 120 and 130 . That is, the second metal sheet 120 , the third metal sheet 130 , and the magnetic shielding unit 140 may have upper surfaces that are coplanar with each other, and their lower surfaces may also form the same plane with each other. . That is, it can be manufactured in the form of an integrated thin thin film sheet.

The step of bonding the magnetic shielding unit 140 to the predetermined regions 122 and 132 ( S30 ) is performed between the bonding region 122b of the second metal sheet 120 and the magnetic shielding unit 140 as shown in FIG. 12 . , disposing the brazing filler 160 between the bonding region 132b of the third metal sheet 130 and the magnetic shielding unit 140 ( S31 ) and brazing bonding ( S32 ) may be included.

The step of disposing the brazing filler 160 (S31) is a brazing filler having a thickness of 1.0 μm or more and 10 μm or less by any one of sputtering, paste application, foil attachment, and P-filler ( 160) can be placed. The brazing filler 160 may be made of an alloy material including at least one of Ag, AgCu, and AgCuTi.

In the brazing bonding step (S32), between the bonding area 122b of the second metal sheet 120 and the magnetic shielding part 140, the bonding area 132b of the third metal sheet 130 and the magnetic shielding part ( 140) by melting the brazing filler 160 disposed in between the second and third metal sheets 120 and 130 made of copper, which is a dissimilar metal, with high-temperature heat, and the magnetic shielding unit 140 made of a cold-rolled steel sheet. have.

The brazing bonding step (S32) is performed at 780 to 900° C., and the upper weight or pressurization may be performed during the brazing bonding. Top weight or pressurization during brazing is for void-free bonding.

The step (S40) of bonding the second metal sheet 120 and the third metal sheet 130 to both sides of the first metal sheet 110 includes the first support part 111 and the second metal sheet 110 of the first metal sheet 110 . The thin film filler layer 150 is disposed between the second metal sheets 120 and between the second support part 112 of the first metal sheet 110 and the third metal sheet 130, and the thin film filler layer 150 is formed. It can be melted with high-temperature heat for brazing bonding. Brazing bonding is carried out at 780 ~ 900 °C, and the upper weight or pressure may be applied during brazing bonding.

On the other hand, the folding plate manufacturing method according to an embodiment of the present invention includes the steps of bonding the magnetic shielding unit 140 (S30), and bonding the second metal sheet 120 and the third metal sheet 130 (S30) ( The method may further include a step (S60) of hot press forming or cold press forming of the second metal sheet 120 and the third metal sheet 130 to which the magnetic shielding unit 140 is bonded (S40). When hot press forming or cold press forming is performed on the second and third metal sheets 120 and 130 to which the magnetic shielding unit 140 is bonded as described above, defects such as waving or bending are prevented by controlling the press load and temperature. It can be removed with more certainty. That is, if even a slight defect such as waving or bending occurs in the folding plate 100, it can be transferred to the display 11 disposed on the upper side as it is, so if necessary, additional hot press forming or cold press forming is performed. can be removed. In addition, dimensional control can be performed through hot press forming or cold press forming, and it can also be processed to a desired thickness.

In this way, the folding plate 100 according to the present embodiment has a magnetic shielding unit 140 in the region corresponding to the first and second magnets 13a and 13b in the second and third metal sheets 120 and 130 made of copper. Since it is brazed, it is possible to manufacture in a thin thickness, and the magnetic shielding effect can be increased, and heat generated from the display 11 can be efficiently dissipated.

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 the 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
12: secondary display 13a: first magnet
13b: second magnet 100,100': folding plate
110,110': first metal sheet 111,111': first support
112,112': second support 120,120': second metal sheet
121,131: step surface 121',131': top surface
121a, 132a, 121'a, 131'a: bonding surface 121b, 131b, 121'b, 131'b: non-bonding area
122,132,122',132': predetermined area 122a,132a,122'a,132'a: hole
122b, 132b, 122'b, 132'b: bonding area 130 and 130': third metal sheet
140,140': magnetic shielding part 141,141': insertion part
142,142': junction 150,150': thin film filler layer
160,160': brazing filler

Claims (18)

a first metal sheet formed with a folding part to be folded;
a second metal sheet and a third metal sheet joined to both sides of the first metal sheet; and
a magnetic shield joined to a predetermined region of the second metal sheet and the third metal sheet;
A folding plate comprising a. The method of claim 1,
The magnetic shielding portion is a folding plate made of a different metal from the second metal sheet and the third metal sheet. 3. The method of claim 2,
The second metal sheet and the third metal sheet are made of copper,
The magnetic shielding portion is a folding plate made of a cold rolled steel sheet material. The method of claim 1,
The predetermined area is
a hole formed through the second metal sheet and the third metal sheet; and
and a bonding area formed at the edge of the hole;
The magnetic shielding part is disposed in the hole, and a junction formed at an edge of the magnetic shielding part is joined to the junction area. 5. The method of claim 4,
The junction region and the junction portion are a stepped surface. According to claim 1,
The second metal sheet, the third metal sheet, and the magnetic shielding portion each top surface forms the same plane with each other,
The second metal sheet, the third metal sheet, and the magnetic shielding portion is a folding plate that forms the same plane with each other when the lower surface. According to claim 1,
Further comprising a brazing filler,
The brazing pillar is a folding plate for bonding the magnetic shielding portion to a predetermined region of the second metal sheet and the third metal sheet. 8. The method of claim 7,
The brazing filler is a folding plate made of an alloy material containing at least one of Ag, AgCu, AgCuTi. According to claim 1,
In a state in which the second metal sheet and the third metal sheet face each other, the magnetic shielding unit bonded to the second metal sheet and the magnetic shielding unit bonded to the third metal sheet are disposed to face each other. According to claim 1,
The first metal sheet has a first support portion and a second support portion formed on both sides, the folding portion is formed in the center,
The second metal sheet is bonded to the lower surface of the first support part, the third metal sheet is joined to the lower surface of the second support part,
A folding plate in which upper surfaces of the second metal sheet, the third metal sheet, and the magnetic shielding portion each form the same plane. preparing a first metal sheet on which a folding part to be folded is formed;
preparing a second metal sheet and a third metal sheet on which predetermined regions are formed;
bonding a magnetic shield to a predetermined region of the second metal sheet and the third metal sheet; and
bonding the second metal sheet and the third metal sheet to both sides of the first metal sheet;
A method of manufacturing a folding plate comprising a. 12. The method of claim 11,
The predetermined area is
a hole formed through the second metal sheet and the third metal sheet; and
and a bonding area formed at the edge of the hole;
The magnetic shielding part is disposed in the hole, and a junction formed at an edge of the magnetic shielding part is joined to the junction area. 13. The method of claim 12,
A method of manufacturing a folding plate in which the magnetic shield portion is half-etched to form the bonding portion corresponding to the bonding area. 13. The method of claim 12,
The step of preparing the second metal sheet and the third metal sheet,
forming the hole by penetrating the second metal sheet and the third metal sheet in a thickness direction; and
and half-etching a peripheral region of the hole to form the stepped junction region. 13. The method of claim 12,
The step of preparing the second metal sheet and the third metal sheet,
forming the stepped junction region by half-etching the second metal sheet and the third metal sheet in a thickness direction; and
and forming the hole by etching through a central partial region of the junction region. 13. The method of claim 12,
The step of bonding the magnetic shielding part is,
disposing a brazing filler between the bonding area of the second metal sheet and the magnetic shielding portion and between the bonding area of the third metal sheet and the magnetic shielding portion; and
brazing bonding;
A method of manufacturing a folding plate comprising a. 17. The method of claim 16,
The step of disposing the brazing filler is,
A folding plate manufacturing method in which a brazing filler having a thickness of 1.0 μm or more and 10 μm or less is disposed by any one of sputtering, paste application, foil attachment, and P-filler. 12. The method of claim 11,
Between the bonding of the magnetic shielding part and the bonding of the second metal sheet and the third metal sheet,
The method of claim 1 , further comprising hot press forming or cold press forming the second metal sheet and the third metal sheet to which the magnetic shielding unit is bonded.

Images