JPH069291B2 - Ink for lift-off - Google Patents

Description

The present invention relates to a lift-off ink for forming a pattern in a screen printing process.

In the prior art] Generally, the flat panel display transparent conductive glass substrate having an ITO film or S _n O ₂ film. This glass substrate is subjected to patterning necessary for forming an electric circuit.

As a pattern processing method for such a transparent conductive film, an etching method, a laser scribing method, an electrolytic corrosion method, and a lift-off method are used. Among these methods, the manufacturing cost,
The lift-off method is superior in terms of mass productivity.

The lift-off method is carried out by a simple process as shown in FIG.

In FIG. 2, (A) shows a printing process, in which the ink 12 is screen-printed on the glass substrate 11. Then B
In the heating step, the glass substrate 11 is heated to desorb the gas from the ink 12. Next, in the film forming step (C), the transparent conductive film 13 having a predetermined thickness is formed on the glass substrate 11 and the ink 12 by the thermal CVD method. Next, in the ink peeling step (D), the ink 12 is removed and the transparent conductive film 13 is removed.
To form a pattern.

The above steps have been described by taking the thermal CVD process as an example.
As can be seen from these steps, the composition of the ink to be printed has a very significant meaning in the pattern processing by the lift-off method.

And, generally, the required performance of the ink is as described below.

(1) Good heat resistance.

(2) The ink and glass do not react.

(3) The ink should not turn up or break during the heating process.

(4) High CVD gas shielding performance.

(5) The ink can be easily dropped in the peeling process after the CVD film formation.

(6) The ink composition has no toxicity.

By the way, conventionally, as a lift-off ink, one having a chlorine group of polyvinyl chloride in its composition has been used for patterning.

[Problems to be Solved by the Invention] However, since such a conventional lift-off ink has a chlorine group of polyvinyl chloride in its composition, the chlorine group reacts with Na on the glass surface, There is a problem that the adhesion between the glass and the ink deteriorates, and when the ink is printed on the glass substrate, the ink peels off after heating.

In order to deal with such a problem, S is preliminarily attached to the glass surface.
_{When the iO 2} film is used as an undercoat, the S _i O ₂ film plays a role of preventing diffusion of Na ions in the glass, so that the ink does not react with Na and the ink can be prevented from peeling off. However, in this case, since the previously formed S _i O ₂ film, a problem that the manufacturing cost of the glass substrate is increased occurs.

In addition, as described above, when the ink is peeled off, the peeled ink scatters in the furnace and is deposited on another glass substrate, and when the film is formed on the glass substrate by the thermal CVD method, the scattered ink part is pinned. There was also a drawback that it would be a hole (film missing).

Further, when chlorine is generated, the chlorine reacts with H ₂ O in the atmosphere and water to generate HCl, which requires a gas treatment facility.

The present invention has been made in view of such conventional problems, by removing the highly reactive chlorine of Na in the glass substrate from the ink composition, it is possible to print directly on the glass substrate, It is an object of the present invention to provide an ink for a lift-off method that can process a good pattern without peeling.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a weight ratio of 30 to 30.
Phenol novolac acrylate, oligoester acrylate, trimethylolpropaine triacrylate in the range of 70%, anthraquinone in the range of 1 to 2%, talc in the range of 30% or more, and the ratio of 8 to 20. % Of titanium oxide, the same ratio of 0.3 to 1% of silicon oil, the same ratio of 1 to 3% of silica, and the same ratio of 0.01 to 1%.
And hydroquinone in the range of.

[Operation] In the present invention, Na of the glass substrate is selected from the ink composition.
Since chlorine that reacts with is removed, it does not peel off from the glass surface even after the ink is baked.

Therefore, the ink can be printed directly on the glass substrate.

Also, pre-S _i O ₂ film need not be formed as an undercoat on a glass substrate, it is possible to greatly reduce the manufacturing cost of the patterned transparent conductive film glass substrates.

Also, since the ink does not peel off, unlike the conventional case, the peeled ink does not scatter and ride on other glass substrates,
Pinholes (film attachment) can be reduced.

Further, since chlorine-free ink is used, there is also an advantage that gas processing equipment for processing gas generated after heating the ink is not required.

EXAMPLES Hereinafter, examples of the present invention will be described in order to more specifically clarify the present invention, but the present invention is not limited by the description of the examples.

In this example, the composition of the lift-off ink was configured as follows.

Composition Weight ratio Phenol novolac acrylate 2.9% Oligoester acrylate 23.5% Trimethylolpropain acrylate 32.1% Anthraquinone 0.75% Talc 30% Titanium oxide 0.2% Silicon oil 0.3% Silica 2.24% Hydroquinone 0.01% Oligoester acrylate (oligomer) is photocurable While phenol novolac acrylate (monomer) and trimethylolpropaine acrylate (monomer) are used for dilution. Of these three, if the total amount of phenol novolac acrylate and trimethylolpropain acrylate exceeds 50% of the total of the three, the properties are not good. Therefore,
It is necessary to reduce these two to 50% or less. Neither oligoester acrylate, phenol novolac acrylate, nor trimethylpropaine acrylate contains chlorine. Moreover, chlorine is not contained in other compositions.

Anthraquinone causes a radical reaction and acts as a sensitizer.

The filler, talc, acts as a dimensional stabilizer and a thickener, and improves peelability.

Titanium oxide, which is a filler, causes a radical reaction,
By acting as a pigment, a dimensional stabilizer, a thickener, and a sensitizer and having a small diameter, for example, 1 μm or less and a small specific gravity, the effect of shielding the thermal CVD gas can be enhanced. However, if it is too large, the peelability is lowered.

Silicone oil acts as an antifoaming agent and silica as a filler acts as a thickening agent. In addition, silica is thermal CVD
If it has a gas shielding effect or is too much, the peelability is reduced.

Hydroquinone acts as an inhibitor, suppressing radical reactions and preventing curing in the sun or under fluorescent light.

Therefore, the pot life (ink life) can be maintained.

As described above, this ink has the composition of Na in glass.
Since chlorine, which has a high reactivity with, is removed, it does not peel off from the glass surface even after the ink is baked.

[Example] Next, an example use of forming a pattern by S _n O ₂ film on a glass substrate by a thermal CVD method using the above ink.

1A to 1D are cross-sectional views showing steps for forming a pattern. Hereinafter, each step will be sequentially described.

Step (a); First, after the ink 2 was adjusted to have a viscosity of 230 to 260 poise, it was applied on the glass substrate 1 of the cleaning agent with a screen printing machine to form a required printing pattern. In this case, the thickness of the ink 2 was set to 10 to 20 μm in terms of long-term stability and ease of ink peeling.

Step (b); Next, the glass substrate 1 on which the ink 2 was directly printed on the glass surface was put into a hot air circulation firing furnace and preheated at a temperature of 300 to 400 ° C. for 10 minutes.

Step (c); Next, the temperature of the preheated glass substrate 1 is 500 to 60.
0 ℃ to put on the adjusted belt-type normal-pressure gas-phase generating device to form a S _n O ₂ film 3 having a predetermined thickness by a thermal CVD method.

Step (d); Next, S _n O ₂ film 3 is gradually cooled glass substrate 1 formed with, and then peeling off the unnecessary ink 2, S with the pattern
_n O ₂ film was obtained glass substrate 1 generated.

As described above, since the ink 2 according to the present invention does not contain chlorine in the ink composition, there is no gas generated by the reaction with Na on the surface of the glass substrate 1, and the ink 2 is peeled from the glass substrate 1 after being heated. There is nothing to do. Therefore, the ink 2 can be printed directly on the glass substrate 1.

When using the ink containing the conventional chlorine, in order to prevent delamination in advance but the S _i O ₂ film had to be under-coat the entire surface of the glass, to print directly ink 2 in the glass substrate 1 Therefore, the manufacturing cost of the glass substrate 2 with the transparent conductive film can be greatly reduced.

Further, conventionally, the ink that has peeled off after the heating step scatters in the furnace and is deposited on another glass, and when a film is formed on it, the scattered ink part becomes a pinhole. Since 2 does not peel off, pinholes can be reduced.

Further, since the ink 2 containing no chlorine is used, a gas facility for processing the gas generated after heating the ink is not required.

In addition, although the case of film formation by the thermal CVD method has been described in this usage example, the invention is not limited to this and the ink of the present invention can be applied to vacuum film formation.

A film forming method using a vacuum process, for example, a resistance heating method, E
In the case of the method B or the sputtering method, it is necessary to sufficiently heat the glass substrate on which the ink is printed to remove the gas component in the ink. Therefore, it is desirable that the preheating is performed in the air at a temperature of 300 to 400 ° C. and the heating time is about 10 minutes.

EFFECTS OF THE INVENTION As described above, according to the present invention, since the ink composition does not contain chlorine, the ink does not peel off from the glass substrate, and as a result, the ink is printed directly on the glass substrate. be able to.

Also, pre-S _i O ₂ film is not necessary to form the glass substrate, it is possible to reduce the manufacturing costs of the transparent conductive film glass substrate with pattern greatly.

Further, since the ink does not peel off, the ink does not scatter and the pinholes can be reduced.

Furthermore, since chlorine-free ink is used, there is no need for a gas processing facility for processing the gas generated after heating the ink.

[Brief description of drawings]

Figure 1 (a) ~ (d) are sectional views showing steps of forming a pattern by S _n O ₂ film on a glass substrate using a lift plate for ink according to the present invention, FIG. 2 (A) ~ (D) is sectional drawing which shows each conventional process. In the figure, 1 ... glass substrate, 2 ... ink, 3 _... S n _{O 2} film.

Claims (1)

[Claims] 1. A phenol novolac acrylate, an oligoester acrylate, and a trimethylolpropaine triacrylate in a weight ratio of 30 to 70%,
Anthraquinone having the same ratio in the range of 1 to 2%, talc having the same ratio of 30% or more, titanium oxide having the same ratio of 8 to 20%, and silicon having the same ratio of 0.3 to 1%. A lift-off ink comprising oil, silica having the same ratio in the range of 1 to 3%, and hydroquinone having the same ratio in the range of 0.01 to 1%.