KR20140147259A - Thermal imaging donor film improving laser conversion - Google Patents

Abstract

The present invention relates to a thermal transfer donor film with enhanced laser transfer attributes. A light-heat conversion layer and an intermediate layer are formed on a support substrate which has multiple base substrates laminated onto each other. The a thermal transfer donor film according to the present invention can minimize the laser transfer failures by reducing the foreign matter defects increasing as the base substrate becomes thicker through laminating the base substrates to form a multi-layer structure. The present invention also reduces the surface energy of the intermediate layer to improve the releasability of a transfer layer and the donor film to improve the quality and laser transfer attributes.

Description

[0001] THERMAL IMAGING DONOR FILM IMPROVING LASER CONVERSION [0002]

The present invention relates to a thermally-assisted donor film having improved laser transfer characteristics, and more particularly, to a structure in which a photo-thermal conversion layer and an intermediate layer are formed on a support substrate on which a base substrate is laminated, , It is possible to minimize defects due to internal defects of the base substrate during laser transfer and lower the surface energy of the intermediate layer to improve the releasability between the transfer layer and the donor film to improve the transfer characteristics and transfer quality in the laser transfer process And more particularly to a donor film for thermoelectric conversion.

Thermal image processing using a laser beam is generally referred to as laser induced thermal imaging (LITI) or hybrid patterning system (HPS), and a donor film as a heat transfer donor element is used Refers to a technique relating to all thermal transfer elements that transfer an organic or inorganic material to another substrate and substrate.

Typically, in a flat panel display, the most common pixel formation method in an organic electroluminescent device is to align a fine metal mask (FMM) on a substrate in a vacuum chamber to sublimate a low molecular weight organic light emitting material to be deposited, The light emitting layer is formed only in the region. In the FMM method, due to the nature of the mask frame, the difficulty of stretching the mask, the deflection of the mask itself, and the expansion due to the temperature, many problems are pointed out in the large-area application. Therefore, a new concept of a process technology for forming a large-area pixel of an organic electroluminescent device is required.

As a representative method for replacing the method of separately forming the R, G, and B light emitting layers using the conventional FMM in accordance with this demand, there are a laser transfer method (LITI), a solution process ink jet ) Method, a white OLED, and a color filter method.

Of these, in the laser technology represented by LITI and LIPS (Laser Induced Pattern-wise Sublimation) or RIST (Radiation Induced Sublimation Transfer), when a laser is irradiated on a donor film or a donor substrate on which a luminescent layer has been formed in advance, And transferred to the acceptor substrate side to form pixels.

In the case of the LITI process used for forming the pixels of the organic electroluminescent device utilizing the above-described donor film / donor substrate including the photo-thermal conversion layer, several methods for manufacturing the donor film have been proposed.

1 is a schematic cross-sectional view of a conventional laser thermal transfer element, which includes a base substrate, a light-to-heat conversion layer, an interlayer, and a transfer layer. layer. A method of forming an organic light emitting layer using such a conventional thermal transfer element will be described. When a laser is irradiated while a substrate on which an organic light emitting layer is to be formed is in close contact with the thermal transfer element, the light heat conversion layer converts laser light into heat As the heat is released, the transfer layer is transferred to the substrate to form an organic light emitting layer.

As described above, the conventional donor film is a constitution including a base substrate composed of a polymer film, a photo-thermal conversion layer, and an intermediate layer, in which light absorbers (pigments or dyes) are irradiated with light by a laser and converted into heat and transferred to an acceptor substrate And has been developed to be mainly used in organic electroluminescent devices (OLEDs).

For example, Korean Patent Laid-Open Publication No. 2005-0023001 relates to a donor film having improved adhesion properties with a transfer layer. By introducing a buffer film between the photo-thermal conversion layer and the transfer layer, the adhesion of the transfer layer to the donor substrate is improved A technology is disclosed.

Korean Patent Publication No. 2007-0024816 discloses a laser thermal transfer apparatus and a method of manufacturing an organic light emitting device using the same. In order to solve the adverse effect on the reliability and lifetime of the conventional product, A donor film for laser induced thermal imaging comprising a conversion layer, wherein the donor film comprises a permanent magnet layer in at least one position between the base substrate and the transfer layer. This transfer method is described in Korean Patent No. 700828. The above-described laser transfer method (LITI) has an advantage of high-resolution pattern formation and large area.

However, in the conventional technique disclosed in the above-mentioned document, there has been no study on the defect of laser transfer due to water inside the PET which is the base substrate, and the range of the laser transfer process suitable for the laser transfer process is very narrow, There is a disadvantage that it has a limited transfer quality. Further, when forming a fine pattern by a laser, there is a problem that an organic material transfer of a desired type of low molecular weight fluorescent substance is not smooth due to a lot of pattern defects.

The present inventors have made efforts to overcome the problems of the prior art. As a result, the present inventors have found that, when a donor film is manufactured, a base substrate is formed in a multilayer structure to minimize defects caused by internal defects of a base substrate during laser transfer, And the donor film to improve the transfer characteristics and the transfer quality in the laser transfer process, thereby completing the present invention.

It is an object of the present invention to provide a thermoelectric conversion donor film having improved laser transfer properties.

Another object of the present invention is to provide a thermoelectric conversion donor film on which a photo-thermal conversion layer and an intermediate layer are formed on a support substrate on which a base substrate is laminated.

According to an aspect of the present invention, there is provided a semiconductor device comprising: a support substrate on which a base substrate is laminated with at least two layers; And a photo-thermal conversion layer and an intermediate layer are formed on the support substrate, wherein the laser transfer property is improved.

In the thermally-transferable donor film of the present invention, the thickness of the base substrate is 10 to 75 mu m, and the thickness of the support substrate is 75 to 125 mu m.

In the thermally-transferable donor film of the present invention, the base substrate is laminated with an adhesive material composed of a polyurethane resin and an isocyanate-based curing agent, and an adhesive layer having a thickness of 1 to 5 m is formed by an adhesive material.

In the thermally-dissertive donor film of the present invention, the intermediate layer may be composed of a resin composition selected from the group consisting of a polyurethane resin, an alkyd resin, a silicone-based polymer, a melamine resin and a polybutadiene acrylate, Or a fluorine-based additive. At this time, the surface energy of the intermediate layer is controlled to be 22 dyne / cm or less. Further, in the thermoelectric use donor film of the present invention, the thickness of the intermediate layer is 1 to 3 占 퐉.

As described above, the thermoelectric conversion donor film of the present invention can reduce the size and number of foreign matter existing in the base substrate by thickening the base substrate and thickening the base substrate, thereby minimizing transfer defects during laser transfer.

Further, the thermoelectric use donor film of the present invention improves the releasing property between the transfer layer and the donor film by lowering the surface energy of the intermediate layer, thereby improving the transfer characteristics and the transfer quality during laser transfer

1 is a schematic cross-sectional view of a conventional donor film,
2 is a schematic cross-sectional view of the donor film according to the present invention,
Figure 3 is a photo untransferred by the water base substrate (PET) naebuyi,
FIG. 4 is a diagram showing a transfer process of the laser transfer method according to the present invention,
5 is a schematic diagram of a laser transfer test according to the present invention.

Hereinafter, the present invention will be described in detail.

FIG. 2 is a schematic cross-sectional view of a thermally-transferable donor film according to the present invention. Specifically, FIG . 2 shows a supporting substrate on which a base substrate 100 is laminated with at least two layers;

The thermally-transferable donor film of the present invention comprises a photo-thermal conversion layer 110, an intermediate layer 120, and a transfer layer 130 on the support substrate, wherein the photo-thermal conversion layer 110 and the intermediate layer 120 ) Are formed.

More specifically, it is impossible to control the internal defects (defects) of the base substrate in the process of forming the thermally conductive donor film. However, when such base substrate is used as it is, defective transfer occurs in the laser transfer process.

FIG. 3 is an untransferred photograph of the inside of the base substrate (PET). Generally, the thicker the base substrate, the larger the size and number of the internal base of the base substrate. As shown in Fig. 3, when there is an internal substance in the donor film, it affects the cell portion (transferred portion), resulting in insufficient transfer and causing pixel defects.

Accordingly, the present invention provides a thermoelectric conversion donor film in which a photo-thermal conversion layer and an intermediate layer are formed on a support substrate laminated on at least two layers of a base substrate having a relatively small thickness and a relatively small thickness.

Thus, since the non-transfer flaws are reduced according to the lamination of the base substrate, the transfer failure during the laser transfer process can be reduced.

More specifically, in the thermoelectric conversion donor film of the present invention, the thickness of the base substrate is 10 to 75 μm, and the thickness of the support substrate is 75 to 125 μm.

In the above, when the thickness of the supporting substrate is 75 m, it does not mean the maximum thickness of the single base substrate of 75 m. That is, the supporting substrate is defined as at least two layers of base substrates laminated together.

Therefore, in the embodiment of the present invention, preferably, when the thickness of the supporting substrate is 100 mu m, the combination of the base substrate is a laminate of 25 and 75 mu m, a laminate of 50 and 50 mu m, Mu] m and a lamination of 50 [mu] m. However, it will be understood that the present invention can be modified and designed within the range of the supporting substrate.

If the thickness of the support substrate of the base substrate 100 is less than 75 mu m, the support layer may not sufficiently function. If the thickness exceeds 125 mu m, the cost may increase. In addition, There is a problem that transmission is disturbed and efficiency is hindered.

In the thermally conductive donor film of the present invention, when the base substrate 100 is laminated, it is laminated by an adhesive material composed of a polyurethane resin and an isocyanate-based curing agent, and an adhesive layer having a thickness of 1 to 5 m is formed by the adhesive material will be.

At this time, the thickness of the adhesive layer influences the transfer characteristics after the laser transfer, and is preferably formed to a thickness of 1 to 5 mu m. If the thickness of the adhesive layer is less than 1 mu m, the two base substrates can not sufficiently laminate. On the contrary, if the thickness exceeds 5 mu m, thermal efficiency during laser transfer is reduced, and sufficient light heat conversion efficiency can not be realized in the photo-

In the thermally-conductive donor film of the present invention, the photo-thermal conversion layer 110 and the intermediate layer 120 are continuously formed on the support substrate. The photo-thermal conversion layer 110 may contain near infrared absorbing dyes as well as carbon black , And the near infrared absorbing dye is a dye which absorbs near infrared rays in a wavelength band of 800 to 1200 nm and is selected from the group consisting of diimmonium dyes, phthalocyanine dyes, naphthalocyanine dyes, anthraquinone dyes, metal- One or more of them may be used, but they may be selected from a group of known materials used for the same purpose in this technical field.

In addition, it is preferable that the photothermal conversion layer forming material contains 20 wt% or less of the photothermal conversion layer forming material. In this case, if the content exceeds 20% by weight, the film may be wrinkled due to damage to the film due to excessive heat transfer.

In the thermoelectric conversion donor film of the present invention, the preferable thickness of the photo-thermal conversion layer 110 is 3 mu m or less, more preferably 1 to 3 mu m. At this time, if the thickness of the photo-thermal conversion layer 110 is more than 3 mu m, there is a problem that the fluorescent layer as a transfer material is damaged due to excessive heat transfer during laser transfer.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. In the present invention, the surface energy of the donor film intermediate layer 120 is reduced to adjust the releasing force so that the adhesion between the transfer layer and the transfer layer becomes greater than the adhesion between the transfer layer and the intermediate layer. The donor film can be easily transferred to the substrate side, thereby improving the transfer characteristics and transfer defects.

The coating liquid for forming the intermediate layer 120 is a polymer resin having soft properties at room temperature during coating and excellent in thermoforming in which transfer is started in a low region due to a low glass transition temperature (Tg).

Examples of the polymer resin include a polyurethane resin, an alkyd resin, a silicone-based polymer, a melamine resin, and a polybutadiene acrylate resin. However, in the art, have.

In order to enhance thermoforming of the intermediate layer 120, one or more selected from a thermosetting resin or a UV curing resin may be used in addition to the above composition.

To increase the cross-linking density of the intermediate layer, a network can be formed by crosslinking using two or more functional groups of acrylate.

Alpha-hydroxy ketones or alpha amino ketones may also be used as UV initiators in the intermediate layer 120 or initiators having a maximum absorption wavelength of 170 to 300 nm corresponding to a short wavelength region may be used .

Particularly, in the thermally-transferable donor film of the present invention, the intermediate layer 120 is formed containing a polymethylsiloxane-based or fluorine-based additive in order to improve the leveling and wettability of the coating solution and to lower the surface energy.

Thus, the surface energy of the intermediate layer 120 of the present invention can be lowered to 22 dyne / cm or less, more preferably 14 to 22 dyne / cm. At this time, if the surface energy exceeds 22 dyne / cm, the transfer characteristic is lowered in the laser transfer process after phosphor deposition.

Thus, the preferable thickness of the intermediate layer 120 in the thermally-transferable donor film of the present invention is 3 mu m or less, more preferably 1 to 3 mu m. At this time, if the thickness of the intermediate layer exceeds 3 탆, the heat transfer which is required by the fluorescent layer may be interrupted, and the problem that the transfer can not be performed may occur.

The photo-thermal conversion layer 110 and the intermediate layer 120 may be formed by a coating method using a nip coater, a bar coater, a gravure coating, and a slot die, do.

Hereinafter, the present invention will be described in more detail with reference to Examples.

The present invention is intended to more specifically illustrate the present invention, and the scope of the present invention is not limited to these embodiments.

< Example  1>

(AD-1) of a polyurethane resin (AD-1 of Adcam Co., Ltd.), 4.5 wt% of an isocyanate curing agent (Aekyung Chemical DN980S) and a solvent of methyl ethyl ketone 25.0% by weight was coated in a thickness of 3 탆 by a bar coater method to form an adhesive layer and dried at 100 캜 for 90 seconds. Thereafter, the same film as above (XU42, 50 mu m, manufactured by Toray Advanced Material Co., Ltd.) was laminated using a lamination machine (GMP EXCELAM Plus 355RM) to prepare a supporting substrate.

A photothermal conversion layer coating liquid having the following composition was coated on one surface of the above-mentioned supported support substrate using a bar coater, dried at 100 ° C for 1 minute, and irradiated with a light quantity of 300 to 500 mJ / Respectively.

After the formation of the photothermal conversion layer, an intermediate layer was formed by the same method using the coating liquid for forming an intermediate layer having the following composition to prepare a donor film. In this case, a metal halide lamp is used for the UV lamp for the LTHC, and a mercury lamp is used for the UV lamp for the intermediate layer.

Composition of photothermal conversion layer coating liquid

Polybutadiene diacrylate (Sartomer CN303): 15.9 wt%

- Crosslinking agent (Sartomer SR344): 5.0 wt%

- CB dispersion (Cabot TPX3301): 12 wt%

- initiator (Iragacure 819): 2.1 wt%

- Silica-based additive (BYK322): 0.2 wt%

- methyl ethyl ketone: 32.40 wt%

- Toluene: 32.4 wt%

Composition of intermediate layer coating liquid

- Polybutadiene diacrylate (Sartomer Corp. CN303): 26.8 wt%

- Crosslinking agent (Sartomer SR238): 5.0 wt%

- initiator (Iragacure 184): 3.0 wt%

- Fluorine Additive (FC4432): 2 wt%

- methyl ethyl ketone: 31.6 wt%

- xylene: 31.6 wt%

< Example  2>

A donor film was produced in the same manner as in Example 1 except that the base substrate (XU42, manufactured by Toray Advanced Material Co., Ltd.) had a thickness of 25 mu m and 75 mu m, respectively.

< Example  3>

Except that a base substrate (XU42, manufactured by Toray Advanced Material Co., Ltd.) having a thickness of 25 占 퐉 was laminated in a four-layer structure with a thickness of 1 占 퐉 as an interlayer adhesive layer to prepare a support substrate, .

< Example  4>

Two layers of a base substrate (XU42, manufactured by Toray Advanced Material Co., Ltd.) having a thickness of 25 mu m and one base layer having a thickness of 50 mu m (XU42, Toray Advanced Material Co., Ltd.) were laminated with a thickness of 1 mu m to form a supporting substrate , A donor film was produced in the same manner as in Example 1 above.

< Comparative Example  1>

A donor film was produced in the same manner as in Example 1, except that a base substrate (XU42, manufactured by Toray Advanced Material Co., Ltd.) having a thickness of 100 mu m was used without any joint.

< Comparative Example  2>

A donor film was produced in the same manner as in Example 1 except that the fluorine-based additive (FC4432) in the composition of the intermediate layer was changed to a silica additive (BYK322).

< Comparative Example  3>

A donor film was prepared in the same manner as in Example 1 except that the thickness of the adhesive layer was 10 mu m.

< Experimental Example  1>

1. Transcriptional characterization test

An organic material (Alq3) was deposited to a thickness of 200 nm on the donor film prepared in Examples 1 and 2 and Comparative Examples 1 to 3, and DNTPD, which is an HTL material, was deposited to a thickness of 300 nm. The transferred donor film was subjected to a transfer test using a LITI apparatus, and the detailed conditions were as follows. Further, in detail, refer to the transfer of a laser-induced thermal imaging process chart shown in FIG.

Laser transcription test conditions

1) Laser source type: Fiber laser

2) Infrared laser wavelength: 1064 nm

3) Laser transfer power output range: 1.0 ~ 6.0A (initial 1.0A spilt / 0.2A split)

4) OLED deposition materials: Alq3 (Green Fluorescent), DNTPD (HTL material)

5) Deposition thickness and speed: 1.0 Å / sec for 2000 Å thick, 1.0 Å / sec for 3000 Å thick

6) Laser line width: about 72 ㎛

2. Surface energy analysis

The surface energy of the intermediate layer was measured using a contact angle meter (Dropmaster 300). At this time, the solution used in the measurement was measured using Kaelbleui equation using purified water (water: distilled water) and n-hexadecane. The measurement results are shown in Table 1 .

3. Analysis of transcription characteristics

After the laser transfer test as in Examples 1 and 2 and Comparative Examples 1 to 3 at all times, the transfer width and the transfer range on the basis of the substrate side (transfer side), the transfer area on the transfer side Quality, and defective number of transcription. The results are shown in Table 1 (average value of 9 points).

4. Laser Transfer Test

As shown in FIG . 5 , using the donor films of Examples 1 and 2 and Comparative Examples 1 to 3, a test plate on which a pattern for measuring the thermal transfer performance of the donor film was formed, ND: YAG 1064 nm wavelength) was performed in an energy range of 60 to 140W. The experimental results are shown in Table 1 below.

As shown in Table 1, in the case of the donor film produced by laminating the base substrate in Examples 1 and 2, the number of defects untransferred by laser transfer was about 1/3 Showed a small result.

Also, by comparing the results of Example 1 and Comparative Example 2, it was confirmed that even the same laminated product affects the transfer characteristics (transfer width and transfer characteristics) and transfer surface quality depending on the surface energy difference.

From the results of Example 1 and Comparative Example 3, it was confirmed that if the thickness of the adhesive layer in the laminating step is large, the transfer characteristics after laser transfer can be lowered.

5. Internal water analysis

Five sheets of A4 size were prepared for each base board. The inner water was counted by reflection and transmission using a three-wavelength lamp, and the inner water was confirmed by using an optical microscope. And the average value thereof is summarized in Table 2 below.

It can be seen from Table 2 that when the base substrate is composed of two layers, it is possible to drastically reduce internal matters.

As described above, the present invention provides a thermoelectric conversion donor film in which a photo-thermal conversion layer and an intermediate layer are formed on a support substrate on which a base substrate is laminated.

In the thermoelectric conversion donor film of the present invention, as the thickness of the base substrate is increased, the size and number of foreign matter defects existing can be reduced to minimize transfer failure during laser transfer, and the surface energy of the intermediate layer By lowering the releasing property, the releasability between the transfer layer and the donor film can be improved, and the transfer characteristics and transfer quality during laser transfer can be improved.

While the invention has been shown and described with reference to certain exemplary embodiments thereof, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined by the appended claims.

100: base substrate 110: photo-thermal conversion layer (LTHC)
120: Interlayer 130: Transfer layer (organic luminescent layer)
140: laser irradiation device 145: laser beam

Claims (8)

A support substrate on which a base substrate is laminated with at least two layers;
A light-to-heat conversion layer on the support substrate; And an intermediate layer formed on the surface of the thermosetting donor film. The thermally-transferable donor film according to claim 1, wherein the base substrate has a thickness of 10 to 75 mu m. The thermally-transferable donor film according to claim 1, wherein the support substrate has a thickness of 75 to 125 占 퐉. The thermoelective donor film according to claim 1, wherein the base substrate is laminated with an adhesive material comprising a polyurethane resin and an isocyanate curing agent. The thermoelective donor film according to claim 4, wherein an adhesive layer having a thickness of 1 to 5 m is formed by the adhesive material. The thermoelective donor film according to claim 1, wherein the intermediate layer is formed from a coating solution containing a polymethylsiloxane-based or fluorine-based additive. The thermally-transferable donor film of claim 6, wherein the intermediate layer has a surface energy of less than or equal to 22 dyne / cm. The thermally-transferable donor film according to claim 1, wherein the intermediate layer has a thickness of 1 to 3 mu m.

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