WO2007046623A1

WO2007046623A1 - Apparatus for continuous metal deposition for mass production

Info

Publication number: WO2007046623A1
Application number: PCT/KR2006/004215
Authority: WO
Inventors: Chang-Hun Hwang; Kyoung-Ook Lee; Jeong-Su Ann; Ki-Ju Park; You-Tae Won
Original assignee: Doosan Mecatec Co., Ltd.
Priority date: 2005-10-19
Filing date: 2006-10-17
Publication date: 2007-04-26
Also published as: TW200718270A; KR100697699B1

Abstract

Disclosed herein is an apparatus for continuous metal deposition. The apparatus comprises at least one casing (20) located on a bottom surface of a deposition chamber, two or more metal boats (30) received in the casing, and a cooling unit to cool the casing (20) and the metal boats (30). Specifically, the chamber is provided with a pair of casings (20), each of which has four metal boats (30) received therein. The apparatus further comprises a transfer unit to horizontally move the casings (20) within the chamber. The apparatus enables continuous deposition of a metallic thin film without destroying vacuum of the deposition chamber for replacement of the boats.

Description

APPARATUS FOR CONTINUOUS METAL DEPOSITION FOR

MASS PRODUCTION

Technical Field

[1] The present invention relates to a metal deposition apparatus, and, more particularly, to an apparatus for continuous metal deposition for mass production of organic light emitting diodes (OLED), which enables continuous deposition of a metallic thin film such as aluminum on a substrate without replacement of a boat when manufacturing the OLED.

Background Art

[2] In recent years, with rapid advancement of information communication technology and expansion of demand in the market, flat panel displays have been in the spotlight as display devices. As for representative flat panel displays, there are liquid crystal displays, plasma display panels (PDP), organic light emitting diodes (OLED).

[3] In particular, due to its excellent characteristics, such as high response rate, light weight, lower power consumption compared with existing LCD devices, ultra thin structure resulting from elimination of a separate backlight unit, high luminance, etc., the OLED is in the spotlighted as one of next generation display devices.

[4] Such an organic light emitting diode is a self-emissive type diode, which generally comprises an anode layer, an organic thin film, and a cathode layer stacked on a substrate such that an appropriate difference in energy is created in the organic thin film via application of voltage between the anode and the cathode, thereby emitting light from the organic thin film. Specifically, holes and the electrons respectively injected from the anode and the cathode are recombined, and then light is generated as a result of energy transition from an exited state to a ground state. At this time, since wavelengths of light can be adjusted by means of an amount of dopant of organic materials, the OLED can embody full color.

[5] Although details of the OLED are not shown in the drawings, the OLED generally comprises an anode, a hole injection layer, a hole transfer layer, a light emitting layer, an electron transfer layer, an electron injection layer, and a cathode sequentially stacked on a substrate. As for the anode, ITO (indium tin oxide) is mainly used, which has small surface resistance and good permeability. In addition, an organic thin film is formed in multiple layers of the hole injection layer, hole transfer layer, emitting layer, electron transfer layer and electron injection layer, in which an organic material for the emitting layer comprises AIq , TPD, PBD, m-MTDATA, TCTA, etc. As for the cathode, a LiF-Al layer is used. [6] Thus, when manufacturing the OLED, it is necessary to deposit the LiF-Al layer for the cathode. With reference to Fig. 1, a conventional deposition apparatus will be described hereinafter.

[7] Referring to Fig. 1, a process of depositing LiF within a conventional metal deposition chamber is generally performed in such a way of heating a crucible 130 which has a vaporizable material received therein.

[8] An aluminum boat 110 is positioned on a bottom surface 100 of the deposition chamber. The aluminum boat 110 comprises a body, a pair of electrodes 111 to which power is applied to generate heat via electrical resistance, and a cavity 112 to which solid aluminum as the vaporizable material is supplied. In addition, a feeder 120 is further provided at one side of the chamber to supply an aluminum wire to the aluminum boat 110.

[9] The aluminum boat 110 is placed at a predetermined distance "d" offset from the center of the chamber to ensure uniform deposition.

[10] In view of operation of the conventional deposition apparatus having the above construction, an aluminum wire wound around a reel is drawn from the feeder 120, and continuously supplied into the cavity 112 of the aluminum boat 110. At the same time, the aluminum wire is heated, and vaporized to be deposited on a target. Disclosure of Invention Technical Problem

[11] The conventional deposition chamber comprises a single aluminum boat 110.

Meanwhile, although the lifetime of the aluminum boat 110 is different depending on size and thickness of the substrate, it is known that the aluminum boat 110 can be generally used for about 180 times of deposition (normal process amount in a day). If the aluminum boat 110 is used more than this, resistance is changed, causing a significant increase in possibility of negative deposition. Thus, conventional deposition chamber has a problem in that the aluminum boat 110 must be replaced with a new one everyday. The apparatus for manufacturing the OLED generally requires six boats, six aluminum wire feeders, and six sensors for a long period of metal deposition processing, generally six days. Thus, the deposition apparatus has a complicated inner construction and is difficult to operate, causing reduction in producibility of the OLED and increase in cost of the apparatus. Technical Solution

[12] The present invention has been made to solve the above problems, and it is an object of the present invention to provide an apparatus for continuous metal deposition for mass production, which enables continuous deposition of a metallic thin film without destroying vacuum of a deposition chamber for replacement of boats. [13] In accordance with one aspect of the present invention, the above and other objects are achieved by provision of an apparatus for continuous metal deposition for mass production, comprising: at least one casing located on a bottom surface of a chamber; two or more metal boats received in the casing; and a cooling unit to cool the casing and the metal boats. [14] The chamber may be provided with a pair of casings, each of which has four metal boats received therein. The apparatus may further comprise a transfer unit to transfer the casing horizontally within the chamber. [15] The casing may be inserted into the chamber through a slit formed in the bottom surface of the chamber. [16] The cooling unit may comprise a refrigerant supply to supply a cooling solvent; and a refrigerant passage constituted by inner walls of the casing and the metal boats.

Advantageous Effects [17] As apparent from the below description, the apparatus according to the present invention eliminates requirement for replacement of a metal boat with new one through destruction of a vacuum state of a deposition chamber, and thus enables a deposition process to be continuously performed, thereby improving producibility.

Brief Description of the Drawings [18] The foregoing and other objects and features of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which: [19] Fig. 1 is a perspective view of an inner construction of a conventional metal deposition apparatus; [20] Fig. 2 is a perspective view of a metal boat assembly according to the present invention;

[21] Fig. 3 is a plan view of the metal boat assembly shown in Fig. 2; and

[22] Fig. 4 is a perspective view of an inner construction of a metal deposition apparatus according to the present invention.

Mode for the Invention [23] Preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. [24] Fig. 2 is a perspective view of a metal boat assembly according to the present invention, and Fig. 3 is a plan view of the metal boat assembly shown in Fig. 2.

Referring to Figs. 2 and 3, the metal boat assembly according to the present embodiment comprises a casing 20, metal boats 30, a body 40, and a transfer unit. [25] The casing 20 has a substantially rectangular parallelepiped shape, and is opened at an upper portion. The casing 20 receives four metal boats 30 that are operated to vaporize aluminum and the like.

[26] Each of the metal boats 30 comprises a pair of electrodes 31 to generate heat via electrical resistance, and a cavity 32 formed between the electrodes 31 to receive an aluminum wire as a vaporizable material supplied from an outside.

[27] The pair of electrodes 31 are connected to a power line 54 which applies power having different polarities to the electrodes, respectively. In addition, each of the electrodes 31 are formed with a cooling water line 53 through which cooling water is supplied to and discharged from the electrodes. The cooling water line 53 is also formed in a side wall of the casing 20.

[28] The body 40 is air-tightly coupled to a chamber through a slit formed in the bottom of the chamber such that the casing 20 and the metal boats 30 can be inserted into the deposition chamber through the slit. For this purpose, the body 40 is formed with a coupling section 41 which allows the body 40 to be coupled to the chamber, and which is formed with bolt holes 42 such that the body 40 is fastened to the chamber along the slit through the bolt holes 42 by means of bolts and nuts. Here, an O-ring 43 is interposed between the coupling section 41 and the chamber to maintain air-tightness therebetween.

[29] The casing 20 and the metal boats 30 are transferred horizontally by the transfer unit. In this embodiment, the transfer unit comprises a motor (not shown) as a driving source, and a ball screw 52 to convert rotation of the motor into a horizontal movement. With this transfer unit, the casing 20 and the metal boats 30 are transferred horizontally along an LM guide 51 within the chamber. This provides the advantage that, even when the lifetime of any one of the metal boats 30 is over, another metal boat 30 can be employed, enabling a deposition process to be continuously performed.

[30] Power and cooling water are respectively delivered along the power line 54 and the cooling water line 53, as described above, which are connected to the corresponding components via bellows 60 so as to maintain air-tightness therebetween.

[31] Fig. 4 shows metal boat assemblies coupled to a deposition chamber. Referring to

Fig. 4, each casing 20 having four metal boats 30 received therein is inserted into the deposition chamber through a slit formed in a bottom surface 10 of the deposition chamber. At this time, the coupling section 41 of the body 40 is fastened to the chamber around the slit by means of bolts and nuts 11. Of course, the O-ring 43 is interposed between the coupling section 41 and the chamber to ensure air-tightness between the body 40 and the chamber.

[32] There will be described operation of a deposition chamber having metal boat assemblies according to the present invention with reference to Fig. 4.

[33] While an aluminum wire is supplied to one of eight metal boats 30 air-tightly positioned within the deposition chamber, a deposition process is performed. At this time, the wire is supplied from a feeder 70. As time goes by, the lifetime of this metal boat 30 expires, and usage thereof is stopped. Instead of replacing this metal boat 30 with another metal boat, a subsequent metal boat 30 is transferred horizontally along an LD guide 51 by a motor and a ball screw 52, and is supplied with the wire such that the deposition process can be continuously performed. In this way, when lifetimes of four metal boats 30 in a single casing 20 expire, the deposition is performed by sequentially supplying the wire to metal boats 30 of a subsequent casing 20.

[34] As apparent from the above description, the apparatus according to the present invention eliminates requirement for replacement of a metal boat with new one through destruction of a vacuum state of a deposition chamber, and thus enables a deposition process to be continuously performed, thereby improving producibility.

[35] It should be understood that the embodiments and the accompanying drawings have been described for illustrative purposes and the invention is limited only by the following claims. Further, those skilled in the art will appreciate that various modifications, additions and substitutions are allowed without departing from the scope and spirit of the invention as set forth in the accompanying claims.

Claims

[1] An apparatus for continuous metal deposition for mass production, comprising: at least one casing located on a bottom surface of a chamber; two or more metal boats received in the casing; and a cooling unit to cool the casing and the metal boats. [2] The apparatus according to claim 1, wherein the chamber is provided with a pair of casings, each having four metal boats received therein. [3] The apparatus according to claim 1, wherein the casing is inserted into the chamber through a slit formed in the bottom surface of the chamber, and is air- tightly coupled to the chamber. [4] The apparatus according to claim 1, further comprising: a transfer unit to transfer the casing horizontally within the chamber. [5] The apparatus according to claim 1, wherein the cooling unit comprises: a refrigerant supply to supply a cooling solvent; and a refrigerant passage formed constituted by inner walls of the casing and the metal boats.