KR20190074556A - Invar prame manufacturing method - Google Patents

Abstract

The present invention relates to an invar frame manufacturing method, which firstly forges an edge portion of a rectangular frame to form a target thickness, rolls a side portion to form the same thickness with the edge portion, and implements forging and rolling processes in a hot state. Therefore, the present invention is possible to obtain a uniform microstructure all over the frame.

Description

{INVAR PRAME MANUFACTURING METHOD}

BACKGROUND OF THE INVENTION 1. Field of the Invention [0002] The present invention relates to a manufacturing method of an Invar frame, and more particularly, to a method of manufacturing an Invar frame supporting a shadow mask in manufacturing an OLED substrate.

OLED (Organic Light Emitting Diode) is a device that emits light by using the electroluminescence phenomenon of an organic material. It is a process in which electrons and holes are injected from electrodes, The light emitted from the light source is used.

OLEDs are attracting a great deal of attention in the display field and illumination field because they have characteristics such as emotional screen realization, high-speed response speed, self-emission, thin manufacturing, low power, wide viewing angle and can use flexible substrates.

OLED display panels are fabricated by vacuum evaporation of RGB (Red, Green, Blue) pixel forming materials, which are three primary colors that form color, from the bottom to the top of the substrate. At this time, the shadow mask, which is a thin thin plate formed with a minute number of fine holes, is positioned below the substrate so that the pixel material passes through the fine holes to accurately deposit the RGB pixel material in a desired region of the substrate. The finer the hole of the shadow mask, the higher resolution image quality can be realized.

Since vacuum deposition is performed at a high temperature, deformation occurs in a shadow mask made of a metal. When such a deformation occurs, the positions of fine holes are changed. As a result, the deposition material can not be deposited at an accurate position, do.

Therefore, the shadow mask is mainly made of INVAR material in order to prevent deformation due to temperature.

In order to keep the shadow mask at a predetermined position in the lower space of the substrate, a frame-shaped frame that supports the shadow mask and does not interfere with the passage of the evaporation material is required. It is made of the same invar material as the mask, and is commonly referred to as the " invar frame ".

The Invar frame was manufactured by drilling a columnar ingot into a cylinder, molding the cylinder into a tube having a flat cross section, and cutting the tube into a required thickness.

However, according to the conventional manufacturing method of Invar frame as described above, when the tube is forged to produce a tube having a rectangular cross section, there is a large difference in the amount of deformation between the corner portion and the side portion, Lt; / RTI >

As described above, the deformation of the Invar frame changes the position of the fine holes of the shadow mask and adversely affects the quality of the OLED panel. Therefore, This uniformly formed invar frame is required.

Korean Patent Publication No. 10-2016-0146105 (December 21, 2016)

Accordingly, the present invention has been made in view of the above-described needs, and it is an object of the present invention to provide an inverted frame capable of improving the quality of an OLED substrate by preventing the deformation during use by uniformly forming internal micro- And a manufacturing method thereof.

According to another aspect of the present invention, there is provided a method of manufacturing a circular cylinder, comprising the steps of: forming a disk by cutting an ingot to form an original plate; forming a cylinder by vertically bending the original plate; A rectangular section forming step for forming a rectangular frame by freely forging the bulged cylindrical body; an edge forming step for shaping the corner section to a target thickness first by freely forging the corner section of the rectangular frame; And a step of shaping the side portions into the same thickness as the edge portions.

The rectangular frame forming step, the corner forming step and the marginal forming step are carried out under conditions of a material temperature of 900 ° C or higher and 1100 ° C or lower and a processing time of 0.5h or higher to 4.0h or lower.

A final heat treatment step is performed after the edge rolling step, and the final heat treatment step is performed under conditions of a material temperature of 950 ° C or higher to 1050 ° C or lower and a temperature holding time of 0.5h or higher to 4.0h or lower.

According to the present invention as described above, the corners of the corners can be made as uniform as possible by performing the corner forming step in which the corners which are severely deformed in the small areas are pressed first through forging with a large deformation amount.

Thereafter, the edge forming step in which the edge portion having a relatively small amount of deformation with respect to the edge portion is pressed through rolling as a whole is carried out, thereby making it possible to uniformize a wide range of texture.

Thereafter, the final heat treatment step is performed, so that there is an effect that the entire structure of the invar frame becomes uniform without any deviation without any difference between the corner part and the side part.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram illustrating a method for manufacturing an Invar frame according to the present invention; FIG.
2 is a block diagram showing a procedure of a method of manufacturing an invar frame according to the present invention;
Figs. 3 (a1) to 3 (a3) are photographs of tissues in the initial state in which no tissue change due to processing has occurred after the disc forming step of Fig.
Fig. 4 is a photograph of the tissues after the rectangular frame molding step of Fig. 2, wherein a1 and a2 are photographs of the corners, and b1 and b2 are photographs of the sides.
Fig. 5 is a photograph of the tissues after the corner forming step of Fig. 2, wherein a1 and a2 are photographs of the corners, and b1 and b2 are photographs of the sides.
Fig. 6 is a photograph of the tissues after the step of forming the marginal portion of Fig. 2, wherein a1 and a2 are photographs of the corners, and b1 and b2 are photographs of the sides.
Fig. 7 is a photograph of the tissue after the final heat treatment step of Fig. 2, wherein a1, a2, and a3 are photographs of the corners, and b1, b2, and b3 are photographs of the edges.

While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that the invention is not intended to be limited to the particular embodiments, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention. The thicknesses of the lines and the sizes of the components shown in the accompanying drawings may be exaggerated for clarity and convenience of explanation.

In addition, the terms described below are defined in consideration of the functions of the present invention, and these may vary depending on the intention of the user, the operator, or the precedent. Therefore, definitions of these terms should be made based on the contents throughout this specification.

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

FIG. 1 is a schematic diagram of a method for manufacturing an Invar frame according to the present invention. FIG. 2 is a block diagram showing a procedure of an Invar frame manufacturing method according to the present invention. As shown in FIGS. 1 and 2, A cylindrical forming step S30, a rectangular frame forming step S40, a corner forming step S50, a marginal forming step S60, And a final heat treatment step (S70).

The disk forming step S10 is a step of cutting the columnar ingot ingot 1 at right angles to the longitudinal direction (horizontal in the drawing) to produce an original plate.

The cylindrical forming step S20 is a step of manufacturing a cylinder 2 by piercing a hole at the center of a circular plate manufactured in the disk forming step S10.

The cylindrical shrinking step S30 is a step of ring-milling the cylinder 2 manufactured in the cylindrical shaping step S20 to expand the diameter of the cylinder 2, 3) in the form of a circular ring.

The rectangular frame forming step S40 is a step of forming a rectangular framed frame (hereinafter referred to as a rectangular frame, reference numeral 3) by freely forging the cylindrical 2 whose diameter is expanded in the cylindrical enlarging step S30.

When the cylinder 2 is deformed into a rectangle, the corner portion 4 has a very large amount of deformation and has a deformation amount of about 50%, and the side portion 5 has a deformation amount of about 10%.

The forging operation in the rectangular frame forming step S40 is performed as a hot forging under conditions of a material temperature of 900 ° C or higher and 1100 ° C or lower and a processing time of 0.5h or higher to 4.0h or lower.

After the rectangular frame 3 is manufactured as described above, the corner portion 4 and the edge portion 5 are processed separately. First, the corner forming step S50 is performed.

The edge forming step S50 is a step of forming the corner portion 4 to the target thickness first by freely forging the four corner portions 4 of the rectangular frame 3.

For example, if the thickness T of the rectangular frame 3 is 80 mm, the corner portion 4 is first hit to form 40 mm (target thickness).

The reason for forging the corner portion 4 first compared to the side edge portion 5 is that the edge portion 4 is formed when the cylindrical 2 (ring-forged product) is manufactured from the rectangular frame 3 (S40) Since the deformation amount of each small section is different from that of the small section even in the corner section 4, a tissue deviation occurs in each small section. Therefore, only the edge section 4 is subjected to free forging, So as to form the internal structure as uniform as possible.

The forging operation in the corner forming step S50 is also performed as a hot forging under the conditions of a material temperature of 900 ° C or higher and 1100 ° C or lower and a processing time of 0.5h or higher to 4.0h or lower.

After the edge forming step (S50), the edge forming step (S60) is performed. The edge forming step S60 is a process of rolling the four sides 5 of the rectangular frame 3 in a state in which only the edge portion 4 is pressed to make the thickness of the edge portion 5 equal to that of the corner portion 4 .

That is, in the case where the thickness of the edge portion 4 is first processed to 40 mm as in the above example, the thickness of the edge portion 5 is also compressed to 40 mm, which is the same as the edge portion 4, by rolling.

When the step S60 is performed as described above, a rectangular frame 3 having a desired shape and dimensions can be obtained.

The rolling in the edge forming step (S60) is performed by hot rolling under conditions of a material temperature of 900 占 폚 to 1100 占 폚 and a processing time of 0.5h to 4.0h.

As described above, the heat treatment conditions for performing the forging and rolling processes in the rectangular frame forming step S40, the corner forming step S50, and the edge forming step S60 are all the same.

That is, forging and rolling are performed within the range of the material temperature of 900 ° C. or higher to 1100 ° C. or lower and the processing time of 0.5 h or more to 4.0 h or lower. The temperature range is a temperature range in which the invar material is deformed by processing, Because the time is the temperature range within which the internal microstructure of the invar material can be recrystallized to a uniform size.

In other words, when the temperature range of the forging and rolling is less than 900 ° C, the material is not smoothly deformed and machining to a desired shape is difficult. When the temperature exceeds 1100 ° C, the deformability is not greatly affected. It has a disadvantage in that it is inefficient because it has to use energy.

When the time range of the forging and rolling is less than 0.5 hours, the processing time is excessively short, which complicates the operation of the equipment and does not sufficiently change the structure. When the time exceeds 4.0 hours, the processing time is excessively long, The energy consumption required for maintaining the material temperature is increased while the organization is not changed.

On the other hand, after forming the rectangular frame 3 satisfying the target shape and dimensions through the edge forming step S60, the final heat treatment step S70 is performed.

The final heat treatment step (S70) is performed under conditions of a material temperature of 950 to 1050 占 폚 and a temperature holding time of 0.5 h or more to 4.0 h or less.

The material temperature range and the time range of the final heat treatment step (S70) are such that the internal stress generated in the previous hot working (forging and rolling processes) is removed, and the texture of 30 탆 or less is uniform It grows in the form of equiaxed crystal grains, and the temperature range is such that tissues already recrystallized do not grow to a great extent.

That is, when the material temperature is less than 950 占 폚 and the temperature holding time is less than 0.5 hours, the internal stress generated in the previous processing is not sufficiently removed and the structure of 30 占 퐉 or less does not grow into a uniform structure in the range of 50 to 80 占 퐉.

Further, when the material temperature exceeds 1050 DEG C and the temperature holding time exceeds 4.0 hours, there is a problem that the already recrystallized structure grows, the structure becomes rough and brittleness occurs and the strength is lowered.

When the final heat treatment step S70 is completed as described above, the invar frame having uniform internal structure as a whole is manufactured.

The function and effect of the present invention will now be described.

FIGS. 3 to 7 are photographs of the tissues after each step of the manufacturing process of the Invar frame.

A photograph of the structure of the ingot ingot 1 serving as the material of the invar frame and the cylinder 2 cut therefrom is the same as a1 to a3 in Fig. That is, the microstructure of the material before the occurrence of the tissue change due to the processing is approximately 150 mu m in average, and thus is substantially uniform.

FIG. 4 shows a photograph of the structure after the cylindrical shrinking step (S30) and the rectangular frame forming step (S40) for performing ring-mill forging and free-forging in a hot state. In Fig. 4, a1 and a2 are photographs of the corner portion 4, and b1 and b2 are photographs of the edge portion 5. Fig. It can be confirmed that the internal structure of the corner portion 4, which has a much greater strain than the edge portion 5 having a small strain by the forging, is very dense. It can also be seen that there is a considerable variation in the size of the structure of the corner portion 4 depending on its position. On the other hand, the edge portion 5 has no significant change compared to the tissue in the previous step S10.

Then, if the edge forming step S50 is performed, the microstructures of the corner portions 4 are uniformly uniformed as a whole as in a1 and a2 in Fig.

At this time, as shown in b1 and b2 of FIG. 5 due to the reheating and air cooling between processes, the unprocessed edge (5) is somewhat compacted as compared with the previous step, but still maintains a relatively large tissue size.

FIG. 6 is a photograph of the tissue after the step S60 is performed. a1 and a2 are photographs of the corner portion 4 and it can be seen that the tissue is relatively grown as compared with the state after the previous stage (corner forming step S50) by reheating, , Showing that the structure is generally uniform and compacted by rolling.

Finally, when the final heat treatment step S70 is performed, as shown in Fig. 7, a1, a2, a3 (photographs of the corner portion 4) and b1, b2, b3 It can be seen that the structure is composed of substantially uniform equiaxed crystal grains (having a size in the range of 50 to 80 mu m and having an average size of 70 mu m) without deviation according to the position.

As described above, according to the method for manufacturing an Invar frame according to the present invention, it is possible to have a uniform microstructure throughout the entire area of the Invar frame despite the sudden change in the shape of the rectangular frame 3 formed by forging the cylinder 2 The inherent physical properties of the invar frame (properties without shape change with respect to temperature changes) are more stably expressed.

Accordingly, since the InVa frame is not deformed during the manufacture of the OLED substrate, the position of the shadow mask supported by the Invar frame is not changed, and deposition materials are deposited on the precise position of the substrate, thereby improving the quality of the OLED substrate.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, It is understandable. Accordingly, the true scope of the present invention should be determined by the following claims.

1: ingot 2: cylinder
3: Rectangular frame 4: Corner
5: side portion

Claims (3)

A plate forming step of cutting an ingot to form an original plate,
A cylinder forming step of punching the disk up and down to form a cylinder,
A cylindrical enlarging step of ring-milling the cylinder to expand its diameter,
A rectangular frame forming step of forming a rectangular frame by freely forging the bulged cylinder,
A corner forming step of free-forming the corner of the rectangular frame to first shape the corner to a target thickness,
A step of molding a side portion of the rectangular frame to mold the side portion to have the same thickness as the edge portion,
≪ / RTI > The method according to claim 1,
Wherein the rectangular frame forming step, the corner forming step and the marginal forming step are carried out under conditions of a material temperature of 900 ° C or higher and 1100 ° C or lower and a processing time of 0.5h or higher to 4.0h or lower. The method of claim 2,
After the edge rolling step, a final heat treatment step is performed,
Wherein the final heat treatment step is performed under conditions of a material temperature of not lower than 950 ° C and not higher than 1050 ° C, and a temperature holding time of not lower than 0.5h and not higher than 4.0h.

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