阅读说明：本技术 掩膜框架组件以及采用该掩膜框架组件的沉积装置 (Mask frame assembly and deposition apparatus using the same ) 是由 安鼎铉 文在皙 李丞赈 于 2019-11-05 设计创作，主要内容包括：本发明的一实施例公开一种掩膜框架组件以及采用该掩膜框架组件的沉积装置,所述掩膜框架组件包括：掩膜,配备有用于沉积的图案区域；以及框架,以层叠有相对强磁性层和相对弱磁性层的包覆结构来支撑掩膜。(An embodiment of the present invention discloses a mask frame assembly and a deposition apparatus using the same, the mask frame assembly including: a mask provided with a pattern area for deposition; and a frame supporting the mask in a clad structure in which a relatively strong magnetic layer and a relatively weak magnetic layer are laminated.)

1. A mask frame assembly including a frame and a mask coupled to the frame and having a pattern region for deposition on a substrate,

the frame includes a clad structure in which a relatively strong magnetic layer and a relatively weak magnetic layer are laminated.

2. The mask frame assembly of claim 1, wherein,

the strong magnetic layer comprises an invar alloy material and the weak magnetic layer comprises a stainless steel material.

3. The mask frame assembly of claim 1, wherein,

the mask is bonded to the weakly magnetic layer.

4. The mask frame assembly of claim 1, wherein,

the mask has a magnetic property relatively stronger than the weak magnetic layer.

5. The mask frame assembly of claim 1, further comprising:

and a long bar coupled to the frame to divide a pattern region of the mask into unit cell patterns.

6. A deposition apparatus, comprising:

a mask frame assembly including a frame and a mask coupled to the frame and having a pattern region for deposition on a substrate;

a magnet for applying magnetic force to the mask frame assembly to make the mask tightly attached to the substrate;

the frame includes a clad structure in which a relatively strong magnetic layer and a relatively weak magnetic layer are laminated.

7. The deposition apparatus of claim 6,

the strong magnetic layer comprises an invar alloy material and the weak magnetic layer comprises a stainless steel material.

8. The deposition apparatus of claim 6,

the magnet is arranged to face the mask frame assembly with the substrate interposed therebetween, and the mask is bonded to the weak magnetic layer of the frame.

9. The deposition apparatus of claim 6,

the mask has a magnetic property relatively stronger than the weak magnetic layer.

10. The deposition apparatus of claim 6,

the mask frame assembly further comprises: and a long-side bar coupled to the frame to divide a pattern region of the mask into unit cell patterns.

Technical Field

The present invention relates to a mask frame assembly used for deposition work and a deposition apparatus using the same.

Background

In general, an organic light emitting display device can represent colors by using the principle that holes and electrons injected from an anode and a cathode are recombined in a light emitting layer to emit light, wherein a pixel is configured by a structure in which a light emitting layer is interposed between a pixel electrode as an anode and an opposite electrode as a cathode.

Each of the pixels may be, for example, a sub-pixel of any one of a red pixel, a green pixel, and a blue pixel, and a desired color may be displayed by a color combination of the sub-pixels of the 3 colors. That is, each sub-pixel has a structure in which a light-emitting layer that emits light of any one of red, green, and blue is interposed between two electrodes, and the color of one unit pixel is displayed by an appropriate combination of the light of these 3 colors.

The electrodes, the light emitting layer, and the like of the organic light emitting display device as described above may be formed by deposition. That is, a mask having pattern holes identical to the pattern of a thin film layer desired to be formed is arranged on a substrate, and a raw material of the thin film is deposited on the substrate through the pattern holes of the mask, thereby forming a thin film of a desired pattern.

The mask is often used in the form of a mask frame assembly together with a frame supporting the end portions thereof and a long bar dividing the pattern hole into a plurality of unit cell patterns, and the mask is closely attached to the substrate by the magnetic force of a magnet when performing deposition work. That is, the magnet is brought close to the surface opposite to the surface of the substrate in contact with the mask, and the magnetic force is exerted to cause the mask to adhere to the substrate, followed by deposition.

And if the deposition for one substrate is finished, the magnet is removed and the substrate is replaced by another one, and then the mask frame assembly is attached to the replaced new substrate, so that the next deposition operation is performed.

Disclosure of Invention

However, if the magnetic force acting on the mask frame assembly is too strong, the following problems may occur when the magnet is removed for the replacement of the substrate: the mask frame assembly is drawn together by the magnetic force so that the position is deviated little by little. That is, the mask frame assembly needs to be continuously maintained at the same position so that the replacement substrate can be always deposited at the same position, but if the position is deviated like this, accurate deposition cannot be performed on the next substrate.

However, if a magnet with a weak magnetic force is used, the mask and the substrate may be lifted up and may not be satisfactorily attached to each other, and a so-called icicle defect in which a serious excessive deposition occurs at the lifted portion or a so-called Shadow (Shadow) defect in which a deposition occurs even in the outline of the originally intended deposition region may easily occur. That is, if the magnetic force acting on the mask frame assembly is too large, a positional variation occurs at the time of substrate replacement, and deposition failure occurs due to weakening of the adhesion force between the substrate and the mask if the magnetic force is too small.

Accordingly, embodiments of the present invention provide a mask frame assembly improved so that positional variation of the mask frame assembly when a substrate is replaced can be suppressed without reducing the adhesion between the mask and the substrate as described above, and a deposition apparatus using the mask frame assembly.

An embodiment of the present invention provides a mask frame assembly, which includes a frame and a mask coupled to the frame and having a pattern region for deposition on a substrate, the frame including a coating structure in which a relatively strong magnetic layer and a relatively weak magnetic layer are stacked.

The ferromagnetic layer may comprise an INVAR (INVAR) material and the weakly magnetic layer comprises a stainless steel material.

The mask may be bonded to the weak magnetic layer.

The mask may have a magnetic property relatively stronger than the weak magnetic layer.

The mask frame assembly, wherein, can also include: and a long bar coupled to the frame to divide a pattern region of the mask into unit cell patterns.

Also, an embodiment of the present invention provides a deposition apparatus, including: a mask frame assembly including a frame and a mask coupled to the frame and having a pattern region for deposition on a substrate; a magnet for applying magnetic force to the mask frame assembly to make the mask tightly attached to the substrate; the frame includes a clad structure in which a relatively strong magnetic layer and a relatively weak magnetic layer are laminated.

The ferromagnetic layer may comprise an INVAR (INVAR) material and the weakly magnetic layer comprises a stainless steel material.

The magnet may be disposed to face the mask frame assembly with the substrate interposed therebetween, and the mask may be bonded to the weak magnetic layer of the frame.

The mask may have a magnetic property relatively stronger than the weak magnetic layer.

The mask frame assembly may further include: and a long-side bar coupled to the frame to divide a pattern region of the mask into unit cell patterns.

Other aspects, features, and advantages in addition to those described above may become apparent from the following drawings, claims, and detailed description.

Drawings

Fig. 1 is a view illustrating a structure of a deposition apparatus using a mask frame assembly according to an embodiment of the present invention.

Fig. 2 is an exploded perspective view of the mask frame assembly shown in fig. 1.

Fig. 3 is a sectional view of the mask frame assembly shown in fig. 1.

Fig. 4a is a graph illustrating magnetization characteristics of a ferromagnetic layer in the mask frame assembly shown in fig. 1.

Fig. 4b is a graph illustrating magnetization characteristics of a weak magnetic layer in the mask frame assembly shown in fig. 1.

Fig. 5 is a sectional view illustrating a variable structure in the mask frame assembly shown in fig. 3.

Fig. 6 is a sectional view showing a detailed structure of the substrate shown in fig. 1.

Detailed Description

While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown in the drawings and will herein be described in detail. The effects and features of the present invention and the methods for achieving the effects and features can be clarified by referring to the embodiments described in detail together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, and may be implemented in various forms.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings, and in the description with reference to the drawings, the same or corresponding constituent elements are given the same reference numerals and repeated description thereof will be omitted.

In the following embodiments, the singular expressions are included unless the context clearly indicates otherwise.

In the following embodiments, the term "include" or "have" indicates the presence of the feature or the constituent element described in the specification, and does not exclude the possibility of addition of one or more other features or constituent elements.

The sizes of the constituent elements in the drawings may be exaggerated or reduced for convenience of explanation. For example, the size and thickness of each component shown in the drawings are arbitrarily set for convenience of explanation, and thus the present invention is not necessarily limited to the contents shown in the drawings.

When certain embodiments may be implemented differently, certain steps may be performed out of order from that described. For example, two steps described in succession may be executed substantially simultaneously, or may be executed in the reverse order to the order described.

Fig. 1 is a view schematically illustrating the structure of a deposition apparatus employing a mask frame assembly 100 according to an embodiment of the present invention.

As shown, the deposition apparatus is equipped with: a mask frame assembly 100 for forming a desired pattern on the substrate 300; a deposition source 200 for spraying a deposition gas toward the substrate 300 in the deposition chamber 400; and a magnet 500 for applying a magnetic force to closely attach the mask 120 of the mask frame assembly 100 to the substrate 300.

Accordingly, if the deposition source 200 ejects a deposition gas within the deposition chamber 400, the deposition gas is adhered to the substrate 300 through the pattern holes 121a (refer to fig. 2) formed in the mask 120 of the mask frame assembly 100, thereby forming a thin film of a predetermined pattern.

Then, if the deposition for one substrate 300 is completed, the magnet 500 is spaced far from the substrate 300 as described above, and after the substrate 300 is replaced with a new substrate, the mask frame assembly 100 is attached to the replaced new substrate 300, and the next deposition operation is performed. The magnet 500 may be in close contact with the substrate 300 as shown in fig. 1 during the deposition operation, or may be in close contact with the substrate 300 at a distance.

In addition, as shown in fig. 2, the mask frame assembly 100 includes a mask 120 formed with pattern holes 121a, a frame 130 supporting both ends of the mask 120, and a long-side bar 110 supported to the frame 130 to perpendicularly cross the mask 120.

The frame 130 is configured to form an outer frame of the mask frame assembly 100, and has a four-sided shape with an opening 132 formed at the center thereof. As shown in fig. 3, the frame 130 is a coated structure in which a plurality of metal layers are laminated.

That is, the structure is formed by stacking the first layer 130a as a relatively strong magnetic layer and the second layer 130b as a relatively weak magnetic layer. The first layer 130a may be formed of an INVAR (INVAR) material, which is an iron-nickel alloy, and the second layer 130b may be formed of a stainless steel material.

The reason why the frame 130 is formed as a coating structure in which the first layer 130a as a relatively strong magnetic layer and the second layer 130b as a relatively weak magnetic layer are laminated in this manner will be described in detail later.

Both ends in the longitudinal direction (X direction) of the long-side rod 110 are fixed to a pair of sides of the frame 130 that face each other by welding, and both ends in the longitudinal direction (Y direction) of the mask 120 are fixed to a pair of sides perpendicular to the sides to which the long-side rod 110 is welded by welding.

The mask 120 is an elongated member, and has a plurality of pattern holes 121a formed in the pattern region 121 located in the opening 132, and both ends of the pattern holes are welded to the frame 130 as described above. Reference numeral 122 denotes a support portion, and when the mask 120 is welded to the frame 130, the support portion 122 is held and welded in a state of being stretched in the longitudinal direction, and a portion protruding outward of the frame 130 is removed by cutting after the welding. Although the mask 120 may be manufactured by using a large member, since the sagging phenomenon due to its own weight may be increased, the mask is divided into a plurality of strips as shown in the drawing. The mask 120 may be made of INVAR (INVAR) or the like.

The pattern holes 121a are holes through which deposition vapor passes when a deposition process is performed, and the deposition vapor passing through the pattern holes 121a adheres to the substrate 300 (see fig. 1) to form a thin film layer.

Here, the pattern regions 121 are not divided into unit cells (cells) of a predetermined specification, but are connected in a long manner, and the long-side bars 110 are formed by dividing the pattern regions 121 into unit cells. That is, as shown in the drawing, the masks 120 and the long-side bars 110 are perpendicularly crossed and closely attached to each other on the frame 130, and thus the long-side bars 110 span the pattern regions 121 of the respective masks 120 and divide the same into unit cells. That is, the long-side bars 110 serve to delimit the boundary lines between the unit cells.

Referring to fig. 3, the frame 130 of the mask frame assembly 100 is configured as a clad structure in which a first layer 130a of INVAR (INVAR) material, which is a relatively strong magnetic layer, and a second layer 130b of stainless material, which is a relatively weak magnetic layer, are stacked as described above.

The reason why the frame 130 is configured as a covering structure in this way is to maintain the magnetic force acting on the mask frame assembly 100 by the magnet 500 at an appropriate level, which is not strong but weak.

If the entire frame 130 is made of the same INVAR material as the mask 120, which is a ferromagnetic layer, a position variation phenomenon of the mask frame assembly 100 frequently occurs when the substrate 300 is replaced. That is, as described above, if deposition on one substrate 300 is finished, the magnet 500 may be lifted to be away from the substrate 300 in order to replace the next substrate 300, but if the magnetic force acting on the mask frame assembly 100 is too large, the mask frame assembly 100 may be pulled by the magnetic force, and a position deviation may occur.

However, if the magnetic force of magnet 500 is reduced, mask 120 and substrate 300 may be lifted and may not be satisfactorily attached to each other, and deposition defects such as so-called icicle defects and shadow defects may easily occur. Therefore, if the magnetic force applied to the mask frame assembly 100 is too large, a positional variation occurs when the substrate 300 is replaced, and a deposition failure occurs because the adhesion force between the substrate 300 and the mask 120 becomes weak when the magnetic force is too small.

In order to solve this problem, in the present embodiment, the frame 130 is prepared as a stacked body of the first layer 130a as a relatively strong magnetic layer and the second layer 130b as a relatively weak magnetic layer, so that it can achieve an appropriate adhesion force by a combination of these strong and weak magnetic properties.

And, the mask 120 is bonded to the second layer 130b, which is a relatively weak magnetic layer. That is, the second layer 130b, which is a relatively weak magnetic layer, is disposed at a side close to the magnet 500, so that a proper relieving effect of the magnetic force is more clearly exhibited.

In this way, the second layer 130b, which is a relatively weak magnetic layer, is inserted into the frame 130, so that the tendency of the entire mask frame assembly 100 to be pulled by the magnet 500 is alleviated, and the mask 120, which is a ferromagnetic material, can be still strongly adhered to the substrate 300 due to the magnetic force of the magnet 500. Therefore, deposition failure can be prevented while maintaining the precision of the deposition position.

Such a frame 130 of a coating structure may be prepared through a hot pressing process, and a detailed manufacturing process for the mask frame assembly 100 including the frame 130 will be described later, and an example of a substrate 300 that may be deposited using the mask frame assembly 100 is briefly described with reference to fig. 6.

The mask frame assembly 100 may be used for deposition of various thin films, for example, may be used for forming a light emitting layer pattern of an organic light emitting display device.

Fig. 6 is an example of a substrate 300 on which a thin film may be deposited using the mask frame assembly 100 of the present invention, and is a view illustrating the structure of the organic light emitting display device.

Referring to fig. 6, a buffer layer 330 is formed on a base plate 320, and a thin film transistor TFT is provided on the buffer layer 330.

The thin film transistor TFT has an active layer 331 and a gate electrode 333 formed to cover the gate insulating film 332 of the active layer 331 and the upper portion of the gate insulating film 332.

The interlayer insulating film 334 is formed to cover the gate electrode 333, and a source electrode 335a and a drain electrode 335b are formed on the interlayer insulating film 334.

The source electrode 335a and the drain electrode 335b are in contact with the source region and the drain region of the active layer 331 through contact holes formed in the gate insulating film 332 and the interlayer insulating film 334, respectively.

A pixel electrode 321 of the organic light emitting element OLED is connected to the drain electrode 335 b. The Pixel electrode 321 is formed on the planarization film 337, and a Pixel defining film 338(Pixel defining layer) for dividing sub-Pixel regions is formed on the Pixel electrode 321. Reference numeral 339 denotes a spacer for maintaining a space between the mask 120 at the time of deposition to prevent damage of the side member of the substrate 300 due to contact with the mask 120, and the spacer 339 may be formed in a form in which a part of the pixel defining film 338 protrudes. Then, the light-emitting layer 326 of the organic light-emitting element OLED is formed in the opening of the pixel defining film 338, and the counter electrode 327 is deposited on the top of these structures. That is, the opening surrounded by the pixel defining film 338 is a region of one sub-pixel such as a red pixel (R), a green pixel (G), and a blue pixel (B), and the light emitting layer 326 of the corresponding color is formed therein.

Accordingly, for example, if the mask 120 is prepared in such a manner that the pattern holes 121a correspond to the luminescent layer 326, the luminescent layer 326 of a desired pattern may be formed through the deposition process illustrated in fig. 1.

The manufacturing process of the mask frame assembly 100 capable of manufacturing such an organic light emitting display device may be performed as follows.

First, when the frame 130 is manufactured, a first layer 130a of an INVAR material as a strong magnetic layer and a second layer 130b of a stainless material as a weak magnetic layer are prepared. The first layer 130a of the INVAR material is a strong magnetic layer having a sharp magnetization characteristic as shown in fig. 4a, and the second layer 130b of the stainless material is a weak magnetic layer having a slow magnetization characteristic as shown in fig. 4 b.

The prepared first layer 130a and second layer 130b are stacked, heated, and pressed to prepare the frame 130 of the coating structure.

The frame of the coating structure may have magnetization characteristics represented by the following magnetic susceptibility.

The magnetic susceptibility of the coating structure (magnetic susceptibility of the ferromagnetic layer x thickness ratio) + (magnetic susceptibility of the weakly magnetic layer x thickness ratio)

Based on the above formula, the magnetic susceptibility of the coating structure is in a proper range by adjusting the thickness ratio of the strong magnetic layer and the weak magnetic layer, thereby completing the mask frame assembly of the present invention.

Next, the long-side bar 110 shown in fig. 2 is welded to the frame 130 to be fixed, and is welded to be fixed after the mask 120 is crossly disposed thereon, thereby completing the mask frame assembly 100.

Also, when performing deposition with the mask frame assembly 100 thus completed, first, the mask frame assembly 100 is disposed within the deposition chamber 400, and the substrate 300, which is a deposition object, is loaded. Then, the magnet 500 is attached to the rear surface of the substrate 300, so that the mask 120 of the mask frame assembly 100 is attached to the front surface of the substrate 300. The deposition source 200 is driven to perform deposition in this state, and if the deposition is completed, the magnet 500 is spaced apart from the substrate 300 in order to replace the substrate 300. At this time, since the second layer 130b, which is a relatively weak magnetic layer, is inserted into the frame 130, the force of the mask frame assembly 100 drawn by the magnet 500 is appropriately relaxed. Therefore, the phenomenon that the position of the mask frame assembly 100 is deviated can be sufficiently suppressed.

When a new substrate 300 is mounted, the magnet 500 is again brought into close contact with the mask 120 to be in close contact with the front surface of the substrate 300, and the mask 120, which is a ferromagnetic body, is strongly brought into close contact with the substrate 300 by the magnetic force of the magnet 500.

Therefore, if the mask frame assembly 100 and the deposition apparatus having such a configuration are used, it is possible to suppress positional variation of the mask frame assembly 100 when the substrate 300 is replaced without reducing the adhesion force between the mask 120 and the substrate 300, and thus it is possible to effectively suppress a failure in which the deposition position is displaced from the correct position, and also possible to suppress a deposition failure such as a icicle failure or a shadow failure. Therefore, stable quality of the product can be ensured.

In addition, in the foregoing embodiment, the case where the cross section of the frame 130 is a quadrangle is shown, but it may be prepared as a trapezoid as in fig. 5. That is, the shape of the display frame 130 is not limited to a certain shape, and can be used by being variously modified.

As described above, the present invention has been described with reference to an embodiment shown in the drawings, but this is merely an exemplary description, and it will be understood by those having a basic knowledge in the technical field of the present invention that various modifications can be made based on the present invention and the embodiment can be modified. Therefore, the true technical scope of the present invention should be determined based on the technical idea of the claims.