JP6034228B2 - Manufacturing method of organic EL thin film forming substrate - Google Patents

Description

  The present invention relates to a method for producing an organic EL thin film forming substrate.

  In order to form an organic EL thin film, a vacuum vapor deposition method is generally used to manufacture a low molecular type organic EL element. In the vacuum deposition method, a method of forming a film with the film formation surface of the glass substrate on which the organic EL thin film is formed facing downward (depot up), and a method of forming a film from the lateral direction with the film formation surface facing sideways (Side depot).

  In recent years, the substrate size of a glass substrate processed by an organic EL thin film forming substrate manufacturing apparatus for manufacturing an organic EL thin film forming substrate has been increased. When forming an organic EL thin film on a glass substrate, after positioning the glass substrate with a vapor deposition mask with high accuracy, the organic EL thin film is formed on the glass substrate by a vacuum vapor deposition method.

  At this time, in a large glass substrate (G5 or more), bending occurs due to its own weight. The bending of the glass substrate has an adverse effect on the alignment of the glass substrate and the vapor deposition mask and the uniformity of the thickness of the film formed by vacuum vapor deposition.

In order to reduce the deflection of the glass substrate, there is a method in which the glass substrate is attached to a flat holding plate using an adhesive sheet or an electrostatic chuck.
Prior art related to substrate bending is described in the following document.

JP 2006-176809 A JP 2005-248249 A

After forming the organic EL thin film by attaching the substrate to the holding plate with an adhesive sheet, it is necessary to remove the substrate from the apparatus. At this time, when the substrate is peeled from the adhesive sheet in vacuum, the substrate is charged, and when the charge amount of the substrate is increased, the substrate is discharged. When a discharge current flows through the organic EL thin film after the organic EL thin film is formed, the light emission characteristics of the organic EL thin film deteriorate, and an organic EL element manufactured using the organic EL thin film becomes a defective product.
An object of the present invention is to reduce the occurrence of defective products due to charging of a substrate.

In order to solve the above-mentioned problems, the present invention is a method in which a back surface of a substrate is pasted to a surface of a substrate holding plate with a substrate adhesive, and an organic EL thin film is formed on the exposed surface of the substrate in a first vacuum atmosphere. The substrate patch is set to one of a low temperature range of 30 ° C. or lower or a high temperature range of 45 ° C. or higher, and a peeling force is provided between the substrate and the substrate holding plate in a second vacuum atmosphere. In addition, the organic EL thin film forming substrate having the organic EL thin film formed on the substrate is peeled from the substrate patch.
This invention is a manufacturing method of the organic electroluminescent thin film formation board | substrate which makes said 2nd vacuum atmosphere the same pressure as said 1st vacuum atmosphere.
This invention is a manufacturing method of the organic electroluminescent thin film formation board | substrate which makes said 1st vacuum atmosphere and said 2nd vacuum atmosphere the pressure below 1.0 * 10 <^-4> Pa.
This invention is a manufacturing method of the organic electroluminescent thin film formation board | substrate which applies the said peeling force and peels from the said board | substrate patch, removing the said board | substrate with the static elimination apparatus.
According to the present invention, a pin is moved with respect to the substrate holding plate from the back side of the substrate holding plate, the pin is inserted into a through-hole formed in the substrate holding plate, and the tip of the pin is connected to the back surface of the substrate. And then the pin is further moved at a relative speed of 1 mm / second or less with respect to the substrate holding plate, and the substrate is pressed to apply a peeling force to the substrate. It is.

  The amount of charge on the substrate can be reduced. Further, since the step of peeling the substrate from the holding plate is performed in a vacuum atmosphere, contamination of the substrate and the organic EL thin film can be prevented.

The figure for demonstrating the manufacturing apparatus of the organic electroluminescent thin film substrate used for this invention (A): a diagram for explaining a substrate holding plate and a substrate (b): a diagram for explaining a film formation target Diagram for explaining the object to be transported The figure for demonstrating the conveyance target object to which the organic EL thin film was adhered (A): The figure for demonstrating the temperature control board and pin raising / lowering device of a temperature control mechanism (b): The figure for demonstrating the temperature adjustment board and pin raising / lowering device in which the film-forming target was mounted. c): A diagram for explaining a state where the substrate is peeled off from the substrate holding plate. Graph showing the relationship between the temperature of the substrate patch and the adhesive strength of the substrate patch Graph showing the relationship between substrate patch temperature and substrate charge

  FIG. 1 shows an organic EL thin film forming substrate manufacturing apparatus 2 used in the method for manufacturing an organic EL thin film forming substrate of the present invention. As shown in FIG. 1, the manufacturing apparatus 2 includes a front chamber 16, a substrate pasting chamber 11, a first inversion chamber 17, a mask pasting chamber 18, a film forming chamber 13, a mask separation chamber 19, The second inversion chamber 25, the substrate peeling chamber 14, the delivery chamber 26, and the rear chamber 15 are provided. Each chamber 11, 13 to 19, 25, 26 is connected via a gate valve 21. When the substrate is loaded from the chambers 11, 13 to 19, 25, 26 into the chambers 11, 13-19, 25, 26 following the chambers, the substrate is provided between the chambers 11, 13-19, 25, 26. The gate valve 21 is opened and the substrate is loaded into the chambers 11, 13 to 19, 25, and 26 that follow each chamber, and the gate valve 21 is closed. Hereinafter, the opening and closing of the gate valve 21 when moving the substrate will be described. Omitted.

  Each chamber 11, 13 to 19, 25, 26 is connected to the evacuation device 22. When each gate valve 21 is closed, each chamber 11, 13 to 19, 25, 26 is connected to the evacuation device 22. Can be individually evacuated.

In advance, each of the gate valves 21 is closed, and each of the chambers 11, 13 to 19, 25, and 26 is evacuated.
When forming the organic EL thin film, the substrate on which the organic EL thin film is to be formed is carried from the front chamber 16 to the substrate pasting chamber 11.
A substrate holding plate 32 is disposed in the substrate pasting chamber 11.

  The substrate holding plate 32 is a plate-like member made of a hard material such as metal (for example, aluminum), and the substrate holding plate 32 is provided with a plurality of holding plate through holes 36 as shown in FIG. ing.

  Assuming that one side of the substrate holding plate 32 is the substrate pasting surface 34 and the opposite side is the back side 54, the holding plate through hole 36 is formed at a portion between the opening located on the surface of the substrate pasting surface 34 and the opening. The substrate patch 33 is affixed. Here, the substrate patch 33 is a sheet-like or flat plate-like substance having adhesiveness. The substrate holding plate 32 is arranged with the substrate sticking surface 34 facing upward, and the loaded substrate 31 faces the film forming surface 37 on which the organic EL thin film is formed facing upward, and the non-film forming on the opposite side thereof. The surface 38 is affixed to the substrate patch 33, and the substrate holding plate 32, the substrate patch 33, and the substrate 31 constitute the film formation target 40 shown in FIG. It is moved to the one reversing chamber 17, and is turned upside down in the first reversing chamber 17, and is moved to the mask bonding chamber 18 with the film formation surface 37 directed vertically downward.

A mask 80 is disposed in the mask bonding chamber 18, and the substrate 31 and the mask 80 are aligned in the mask bonding chamber 18. As shown in FIG. A mask 80 is disposed on the film surface 37, and the mask 80 is fixed to the film formation target 40.
A window portion 81 that is a through hole is formed in the mask 80, and the film formation surface 37 is exposed on the bottom surface of the window portion 81.

  When the mask 80 and the film formation target 40 are referred to as a transfer target 44, the transfer target 44 is moved from the mask bonding chamber 18 to the film formation chamber 13, and the substrate transport provided in the film formation chamber 13 is performed. Arranged in the apparatus 41 and moved inside the film forming chamber 13 with the film forming surface 37 facing downward.

  A plurality of vapor release devices 43 (here, 10 to 15 units) are provided on the bottom side inside the film forming chamber 13. Each of the vapor discharge devices 43 has a vapor discharge port (not shown) that discharges vapor, so that the organic compound vapor of the organic EL thin film material can be discharged from the vapor discharge port into the film forming chamber 13. Has been.

The inside of the film forming chamber 13 is continuously evacuated at least while the transfer object 44 moves inside the film forming chamber 13, and the atmosphere inside the film forming chamber 13 is a first pressure within a predetermined pressure range. In a vacuum atmosphere, the organic compound vapor is released upward from the vapor discharge ports of the respective vapor discharge devices 43, and the film formation surface 37 faces the vapor discharge ports of the respective vapor discharge devices 43 in order. Then, when the organic compound vapor sequentially reaches the film formation surface 37 exposed on the bottom surface of the window portion 81, an organic EL thin film is formed on the film formation surface 37 exposed on the bottom surface of the window portion 81 as shown in FIG. 39 is formed. (At this time, an organic EL thin film is also formed on the surface of the mask 80.)
When the organic EL thin film 39 is formed, heat flows into the object to be transported 44, and the temperature of the substrate 31 and the temperature of the substrate patch 33 are less than those immediately before the organic EL thin film 39 is formed. Immediately after the formation, the temperature is higher than 30 ° C.

  Since the adhesive force of the substrate patch 33 becomes weaker as the temperature increases, the adhesive force between the substrate 31 and the substrate patch 33 is maintained in a temperature range lower than 45 ° C. in order to maintain the strength at which the substrate 31 does not fall. The organic EL thin film 39 is formed while cooling the substrate 31 and the substrate patch 33 by the cooling mechanism 35 (FIG. 1) provided in the film forming chamber 13.

In the manufacturing apparatus 2, the cooling mechanism 35 is disposed between the ceiling of the film forming chamber 13 and the vapor discharge device 43.
The conveyance object 44 having the substrate 31 on which the organic EL thin film 39 is formed is moved from the film formation chamber 13 to the mask separation chamber 19.

  In the mask separation chamber 19, the mask 80 and the film formation target 40 are separated from the conveyance target 44, and the separated mask 80 moves in a vacuum atmosphere and is returned to the mask bonding chamber 18 to be formed. The film object 40 is moved from the mask separation chamber 19 to the second inversion chamber 25.

  In the second inversion chamber 25, the moved film formation target 40 is turned upside down, the film formation surface 37 of the substrate 31 on which the organic EL thin film 39 is formed is directed upward, and the substrate holding plate 32 is moved downward. The second inversion chamber 25 is moved into the substrate peeling chamber 14 while being directed to the substrate peeling chamber 14.

The inside of the substrate peeling chamber 14 is continuously evacuated, and the second vacuum atmosphere that is the atmosphere inside the substrate peeling chamber 14 is set to the same pressure as the first vacuum atmosphere. Here, the first vacuum atmosphere and the second vacuum atmosphere are pressures less than 1 × 10 ⁻⁴ Pa.

As shown in FIG. 1, a stage 55 is disposed on the bottom surface of the substrate peeling chamber 14, and a plate-shaped temperature adjustment plate 63 included in the temperature adjustment mechanism 60 is disposed on the ceiling side.
Inside the temperature adjusting plate 63, a medium flow path 65 through which the heat medium 62 flows is provided.

  A temperature control device 67 is disposed outside the substrate peeling chamber 14. The medium flow path 65 is supplied with the heat medium 62 from the temperature control apparatus 67, and the heat medium 62 flowing through the medium flow path 65 has a temperature. It is configured to return to the control device 67.

  The temperature control device 67 includes a heating / cooling device that controls the temperature of the heat medium 62 by heating or cooling the heat medium 62, and the heat medium 62 that has returned to the temperature control device 67 is heated by the heating / cooling device. Are controlled and supplied to the medium flow path 65.

  One surface of the stage 55 is a flat mounting surface 56, and a moving hole for raising and lowering the pin 52 is formed in the stage 55. FIG. 5A shows a plurality of holes inserted through the moving holes. The upper end of the pin 52 is in a state of protruding on the placement surface 56.

  Each pin 52 is attached to a pin lifting / lowering device 53 (FIG. 1), and the pin 52 is lowered below the placement surface 56 by the pin lifting / lowering device 53 and then carried into the substrate peeling chamber 14. The film object 40 is inserted between the stage 55 and the temperature adjustment plate 63, aligned so that the holding plate through-hole 36 is positioned above the pin 52, and then lowered, as shown in FIG. As shown in FIG. 3, the film formation surface 37 is placed on the placement surface 56 with the upper surface thereof directed upward.

In this state, the holding plate through hole 36 communicates with the moving hole. The film formation surface 37 faces the temperature adjusting plate 63 in close proximity to each other, and the temperature adjusting plate 63 makes the radiant heat incident on the substrate 31 or absorbs the radiant heat of the substrate 31. Thus, the temperature of the substrate 31 is raised or cooled, and the temperature of the substrate 31 and the substrate patch 33 can be controlled by controlling the temperature of the heat medium 62.
The temperature of the board | substrate 31 and the board | substrate patch 33 when it carries in in the board | substrate peeling chamber 14 is a temperature range higher than 30 degreeC and lower than 45 degreeC.

  When the temperature of the substrate patch 33 placed on the stage 55 in the temperature range is controlled by the temperature adjustment plate 63, either the low temperature range of the substrate patch 33 is 30 ° C. or lower or the high temperature range of 45 ° C. or higher. The temperature of the heat medium 62 within the temperature range and the time for facing are determined in advance, and the film formation target 40 placed on the stage 55 is heated by the heat medium 62 supplied by the temperature controller 67. The temperature of the substrate patch 33 is controlled to be a low temperature range or a high temperature range.

In the case of the low temperature range, it is usually a temperature range of room temperature (20 ° C.) or more. In the case of the high temperature range, the thin film formed on the substrate 31 is not damaged. It is normal.
When the temperature is in the low temperature range or the high temperature range, the pin 52 is raised.

  Above the pins 52, the non-deposition surface 38 of the substrate 31 is exposed. The substrate holding plate 32 is fixed to the stage 55, and the tip of the rising pin 52 comes into contact with the non-film-formation surface 38. When further rising is attempted, a pressing force is applied to the substrate 31 from below, and the pressing force is applied. Becomes the peeling force. When the peeling force is larger than the contact force, the substrate 31 peels from the substrate patch 33.

A neutralization device (in this case, an ultraviolet lamp 72) is disposed at a side position of the stage 55 inside the substrate peeling chamber 14, and a lamp power source 73 is disposed outside the substrate peeling chamber 14.
When the lamp power source 73 is activated, the ultraviolet lamp 72 is energized, the ultraviolet lamp 72 is turned on, and ultraviolet rays are emitted from the ultraviolet lamp 72 toward the space on the mounting surface 56.
The ultraviolet lamp 72 is turned on when the substrate 31 is peeled from the substrate patch 33 so that the non-film-forming surface 38 is irradiated with ultraviolet rays.

  When the substrate 31 is peeled off, the temperature of the substrate patch 33 is set to a low temperature range or a high temperature range so that the charge amount is reduced. Further, the substrate 31 is less charged by irradiating the non-deposition surface 38 with ultraviolet rays.

  The pin lifting device is configured to be able to raise the pin 52 at a desired speed. Here, after the pin 52 comes into contact with the non-film-forming surface 38, the pin 52 is 0.1 mm / second. The speed is increased at a speed of 1 mm / second or less, and the speed is made slower than the conventional pin moving speed so as to reduce charging.

FIG. 5C shows the substrate 31 peeled from the substrate holding plate 32.
In the above-described peeling method of the substrate 31, the pins 52 are pressed against the substrate 31 and the substrate 31 is peeled off from the substrate holding plate 32 by the pressing force, but the substrate 31 is peeled off by the tensile force that pulls the substrate 31. It may be peeled off.

Further, at the time of peeling, an inert gas may be introduced into the substrate peeling chamber 14 so that the second vacuum atmosphere has a pressure of 1 × 10 ⁻⁴ Pa or higher, and the static eliminator is not the ultraviolet lamp 72. May be. Further, it is not necessary to provide a static eliminator inside the substrate peeling chamber 14.

  Further, the plurality of pins 52 may rise at the same speed, or may rise at different speeds between the pins 52 and 52.

  In addition, the temperature adjustment plate 63 of the temperature adjustment mechanism 60 is provided at a position facing the substrate 31 of the film formation target 40 so as to be separated from the film formation target 40. 65, and the heat medium 62 is supplied to the medium flow path 65 and circulated so that the stage 55 serves as the temperature adjustment plate 63 and the temperature adjustment plate 63 is arranged so as to be in contact with the film formation target 40. good.

After the pins 52 are raised and the substrate 31 on which the organic EL thin film is formed is peeled off from the substrate patch 33 and separated from the substrate holding plate 32 and the substrate patch 33, the substrate holding plate 32 is placed in a vacuum atmosphere. Is moved back to the substrate pasting chamber 11, and the separated substrate 31 is moved into the rear chamber 15, and the substrate 31 is subjected to the following processing.
Although the substrate 31 is a glass substrate, a dielectric substrate other than the glass substrate can be used in the present invention.

[Relationship between temperature of substrate patch, adhesive strength of substrate patch and amount of charge of substrate]
In this example, butadiene rubber was used for the substrate patch 33 and aluminum was used for the substrate holding plate 32. In addition, an approximately 50 mm square square non-film-formed glass substrate was used as the sample substrate. The substrate patch 33 is affixed to the substrate holding plate 32, the sample substrate is placed on the substrate adhesive 33, pressed with a force of 20N from above, and the sample substrate is affixed to the substrate adhesive 33 and fixed. A sample of the membrane object was obtained. Here, the relationship between the temperature of the substrate patch 33 and the adhesive force of the substrate patch 33 when a plurality of samples of the film formation target are prepared and the sample substrate is peeled off from each film formation target, The relationship between the temperature of the substrate patch 33 and the charge amount of the substrate 31 was measured.

  Table 1 shows the relationship between the temperature and the average value of the adhesive force measurement results, and Table 2 shows the relationship between the temperature and the standard value of the average value of the charge amount measurement results. The standard values shown in Table 2 are standard values when the charge amount (760.9 V) when the substrate patch 33 is peeled off at 30 ° C. is 1.

  The relationship between the temperature shown in Table 1 and the adhesive strength is shown in FIG. 6, and the relationship between the temperature shown in Table 2 and the charge amount is shown in FIG. The horizontal axis of the graphs shown in FIGS. 6 and 7 is the temperature of the substrate patch 33, the vertical axis of FIG. 6 is the average value of the measurement results of the adhesive strength, and the vertical axis of FIG. The standard value of the value is shown.

  When the adhesive force and the charge amount were measured, in addition to the temperature of the substrate patch 33, the temperature of the substrate 31 affixed to the substrate patch 33 was also measured. The measurement temperature of 31 and the board | substrate patch 33 was described.

From Table 1 and FIG. 6, in the substrate patch 33 using butadiene rubber, the adhesive strength of the high-temperature substrate patch 33 is lower in the temperature range of 23 ° C. or more and 60 ° C. or less. It is smaller than the adhesive strength.
Accordingly, the peeling force is smaller in the high temperature range than in the low temperature range.

  On the other hand, from Table 2 and FIG. 7, when the temperature of the substrate patch 33 is within a temperature range of 23 ° C. or more and 35 ° C. or less, the higher the temperature of the substrate patch 33 is, the higher the charge amount is. In the temperature range of 35 ° C. or more and 60 ° C. or less, the charge amount is smaller when the temperature of the substrate patch 33 is higher than when it is lower. As a result, when the temperature of the substrate patch 33 is 35 ° C. In addition, the charge amount of the sample substrate is the largest.

  From the above results, it can be seen that the lower the temperature of the substrate patch is lower than 35 ° C. or the higher the temperature is higher than 35 ° C., the less the organic EL thin film 39 is destroyed due to charging discharge. . When the temperature of the substrate patch 33 is set to a low temperature region of 20 ° C. to 30 ° C. lower than 35 ° C. or a high temperature region of 45 ° C. to 80 ° C. higher than 35 ° C. It has been confirmed that the problem of device failure due to deterioration of the EL thin film 39 does not occur.

[Relationship between pin movement speed and substrate charge]
In this example, butadiene rubber was used for the substrate patch 33 and aluminum was used for the substrate holding plate 32. The sample substrate was a 300 mm × 400 mm rectangular non-film-formed glass substrate. The substrate patch 33 is affixed to the substrate holding plate 32, the sample substrate is placed on the substrate adhesive 33, pressed from above, and the sample substrate is affixed to the substrate adhesive 33 and fixed. A sample was obtained. When the temperature of the substrate patch 33 was 24 ° C., the relationship between the moving speed of the pins 52 and the charge amount of the sample substrate when the sample substrate was peeled from the sample of the film formation target was measured. The measurement results are shown in Table 3 below. The values shown in Table 3 below are standard values when the charge amount (9200 V) of the sample substrate when the pin moving speed is 2 mm / second is 1.

From the numerical values in Table 3, the standard values of the charge amount of the substrate 31 when the moving speed of the pin 52 is 2 mm / second, 1 mm / second, and 0.1 mm / second are 1.00, 0.39, and 0, respectively. In the range where the moving speed is 0.1 mm / second or more and 2 mm / second or less, the charge amount of the sample substrate is smaller when the moving speed of the pin 52 is slower than when the moving speed is faster.
From Table 3, it can be seen that the moving speed is preferably 1 mm / second or less.

2 ... Organic EL thin film forming substrate manufacturing apparatus 11 ... Substrate pasting chamber 13 ... Deposition chamber 14 ... Substrate peeling chamber 22 ... Vacuum exhaust device 31 ... Substrate 39 ... Organic EL thin film 32 ... Substrate holding Plate 33 ... Substrate adhesive 34 ... Substrate attachment surface 36 ... Holding plate through hole 40 ... Film formation target 44 ... Transport target 41 ... Substrate transport device 43 ... Vapor release device 53 ... Pin lifting Device 55 ... Stage 56 ... Mounting surface 60 ... Temperature control mechanism 65 ... Medium flow path 63 ... Temperature control plate 67 ... Temperature control device 71 ... Ultraviolet irradiation device 72 ... Ultraviolet lamp

Claims (5)

Affix the back side of the substrate with the substrate adhesive on the surface of the substrate holding plate,
After forming the organic EL thin film in the first vacuum atmosphere on the exposed surface of the substrate,
The substrate patch is set to one of a low temperature range of 30 ° C. or lower or a high temperature range of 45 ° C. or higher, and a peeling force is applied between the substrate and the substrate holding plate in a second vacuum atmosphere. And the manufacturing method of the organic EL thin film formation board | substrate which peels the organic EL thin film formation board | substrate with which the said organic EL thin film was formed in the said board | substrate from the said board | substrate patch.   The method of manufacturing an organic EL thin film forming substrate according to claim 1, wherein the second vacuum atmosphere is set to the same pressure as the first vacuum atmosphere. The manufacturing method of the organic electroluminescent thin film formation board | substrate of Claim 2 which makes said 1st vacuum atmosphere and said 2nd vacuum atmosphere into the pressure of less than 1.0 * 10 <^-4> Pa.   4. The method of manufacturing an organic EL thin film forming substrate according to claim 1, wherein the substrate is peeled from the substrate patch by applying the peeling force while discharging the substrate with a static eliminator. 5. .   A pin is moved relative to the substrate holding plate from the back side of the substrate holding plate, the pin is inserted into a through hole formed in the substrate holding plate, and the tip of the pin is brought into contact with the back surface of the substrate. After that, the pin is further moved at a relative speed of 1 mm / second or less with respect to the substrate holding plate, and the substrate is pressed to apply a peeling force to the substrate. The manufacturing method of the organic electroluminescent thin film formation board | substrate of description.

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