JP5099989B2 - Ink application method - Google Patents

Description

  The present invention relates to a method for applying ink onto an object to be coated having a step using an ink jet method, and is particularly suitable for forming a wiring pattern or the like on a mounting substrate or a pattern such as a biochip. The present invention relates to an ink application method.

  Conventionally, when this type of pattern is formed, methods such as metal film formation, photolithography, and etching are used. However, there are problems such as a long process, low material utilization efficiency, and generation of waste liquid. .

  Under such a background, printing methods such as screen printing have been studied. However, in the case of printing methods, a mask is necessary, and there is a disadvantage that it is not suitable for drawing on a substrate having steps.

  On the other hand, an ink jet method capable of forming a pattern without contact from digital data is superior to the above-described method as a wiring forming method for a substrate having a step.

  However, for example, when the wiring pattern 103 is formed by the inkjet method on the substrate 101 having a step as shown in FIG. 2A, as shown in FIG. 2B, the valley portion of the bent portion of the step. In 102b, the width of the wiring widened (indicated by reference numeral 103b), and in the peak portion 102a, the wiring width narrowed (indicated by reference numeral 103a) occurred.

Such widening of the wiring width increases the risk of short-circuiting due to contact with adjacent wiring, and the narrowing of the wiring width may cause an increase in wiring resistance.
JP 2002-164181 A

  The present invention has been made to solve the above-described problems of the prior art, and provides a technique capable of forming a pattern with a constant line width using an inkjet method on an object to be coated having a level difference. With the goal.

  As a result of intensive efforts to solve the above-mentioned problems, the inventors of the present invention can control the expansion and narrowing of the line width when a predetermined roundness is formed in the stepped valley portion or the peak bending portion of the application target, and the constant The inventors have found that a line width pattern can be formed and have completed the present invention.

The present invention made on the basis of such knowledge, as described in claim 1, when applying ink across the bent portion of the step on the application target having a step, the application object a method of applying ink previously formed rounded portion in the bent portion of the step, landing diameter D of the ink and the curvature radius R of the rounded portion, to satisfy the relationship of R ≧ (D / 4), In addition, the radius of curvature R of the rounded portion is 100 μm or less, and the landing diameter D of the ink is 50 μm or more and 100 μm or less .
According to a second aspect of the present invention, in the first aspect of the invention, a rounded portion that curves in a direction straddling the bent portion of the step is formed.
The invention according to claim 3 is the invention according to any one of claims 1 or 2, wherein a rounded portion is formed in the convex bent portion of the step.
The invention according to claim 4 is the invention according to any one of claims 1 to 3, wherein a rounded portion is formed in the concave bent portion of the step.
According to a fifth aspect of the present invention, in the invention according to any one of the first to fourth aspects, an ink containing metal fine particles is used as the ink, and a wiring pattern is formed on the coating object.

  In the case of the present invention, since the flow of ink can be suppressed by forming a rounded portion in advance in the convex or concave bent portion of the step of the application object, it is uniform in the application object having a step. A wiring pattern having a line width can be formed.

  In the present invention, when forming a rounded portion that curves in a direction that crosses a bent portion of a step, it is possible to form a pattern with a constant line width by reliably preventing ink from spreading or thinning in the line width direction. become.

In the present invention, landing diameter D of the radius of curvature R and the ink of the rounded portion, to satisfy the relationship of R ≧ (D / 4), and, with a radius of curvature R of the rounded portion is 100μm or less, the ink Since the landing diameter D is 50 μm or more and 100 μm or less, it becomes possible to form a pattern having a constant line width while preventing the line width from being further expanded or thinned.

  Further, in the present invention, when an ink containing metal fine particles is used as an ink and a wiring pattern is formed on an object to be coated, a pattern with a constant line width can be formed. An increase in the resistance value of the wiring can be suppressed.

  According to the present invention, a wiring pattern or the like having a certain line width can be formed using an inkjet method even for a coating object having a step.

Hereinafter, preferred embodiments of an ink coating method according to the present invention will be described in detail with reference to the drawings.
1 (a) and 1 (b) are schematic explanatory views of an embodiment of the present invention. FIG. 1 (a) shows a state before ink is applied, and FIG. 1 (b) shows ink applied. This shows the state after the operation.

Hereinafter, in the present specification, a case where a step having an inclination angle of θ and a height difference between a crest portion and a trough portion is formed on a glass substrate will be described as an example.
In consideration of ink dripping, the step inclination angle θ is preferably as small as possible, but is not particularly limited in the present invention.

  As shown in FIG. 1A, in the present embodiment, in the ink application region of a glass substrate (application object) 1 made of, for example, quartz, stepped convex and concave bent portions, that is, peaks The rounded portion 2 (2a, 2b) is formed in advance in the portion and the valley portion.

  In this case, the rounded portion 2 (2a, 2b) is formed so as to bend in a direction across the bent portion of the step, that is, in the direction of forming the pattern, from the viewpoint of making the pattern width (line width) more constant. It is preferable.

In the present invention, although not particularly limited, from the viewpoint of making the line width more constant, the radius of curvature R of the rounded portion 2 formed at the bent portion of the step and the landing of the ink to be applied It is preferable to form the rounded portion 2 so that the diameter D satisfies the relationship of R ≧ (D / 4).

In the present invention, the method for forming the rounded portion 2 is not particularly limited, but it is preferably formed by an RIE (reactive ion etching) method or the like from the viewpoint of performing an isotropic etching process.
And the wiring pattern 3 is formed by discharging the ink 11 from the inkjet head 10 with respect to the glass substrate in which such a round part 2 was formed, as shown in FIG.1 (b).

As described above, according to the present embodiment, the rounded portions 2a and 2b that are curved in a direction straddling the bent portion are formed in advance on the convex or concave bent portion of the step of the glass substrate 1, Since the flow of the ink 11 in the line width direction can be suppressed, it is possible to form the wiring pattern 3 having a constant line width while preventing the line width from widening or narrowing.
As a result, according to the present embodiment, it is possible to suppress a short circuit between wirings formed by an ink jet method and an increase in the resistance value of the wirings.

The present invention is not limited to the above-described embodiment, and various changes can be made.
For example, in the above embodiment, the rounded portion that curves in the direction across the bent portion of the step, that is, the direction in which the pattern is formed is formed, but the present invention is not limited to this, and the bent portion of the step is formed. It is also possible to form the rounded portion by inclining the angle with respect to the straddling direction.
The present invention can be used when forming various patterns in addition to the wiring pattern for electrical connection.

Examples of the present invention will be described below in detail together with comparative examples.
The electrode wiring of the silica gel capillary electrophoresis chip was formed by drawing Ag nanometal ink (manufactured by ULVAC Material Co., Ltd.) by the ink jet method.

  In this capillary electrophoresis chip, a sample is introduced into a microchannel made inside a glass or plastic chip, and a sample is separated while a solution flows in a separation channel by applying a voltage in the channel. Thus, it is used in the biotechnology field including DNA analysis.

<Example 1>
First, a channel was formed on a quartz substrate using a three-dimensional carbon dioxide laser device.
Specifically, a quartz glass substrate having a shape as shown in FIG. 1 and having a step height of 500 μm is used, and the bent portion is rounded by a carbon dioxide gas laser so that the radius of curvature is R1 = 25 μm and R2 = 50 μm (rounding). Processing). Then, a wiring having a width of 100 μm was formed on the glass substrate by an inkjet method using Ag nanometal ink (manufactured by ULVAC Material Co., Ltd.).

The droplet volume of the applied ink was 12 pl, and the landing diameter on the quartz glass substrate was 50 μm.
In addition, as an inkjet head, Spectra SX-128 head was used.

<Example 2>
A wiring pattern was formed in the same manner as in Example 1 except that the radius of curvature of the rounding process was R1 = 12.5 μm and R2 = 25 μm.

<Example 3>
The volume of the ink droplet to be applied was 50 pl, and the landing diameter on the quartz glass substrate was 100 μm.
In addition, Spectra SM-128 head was used as the inkjet head.
Further, the radius of curvature of the rounding process was set to R1 = 50 μm and R2 = 100 μm, and other than that, the wiring pattern was formed in the same manner as in Example 1.

<Example 4>
The volume of the ink droplet to be applied was 50 pl, and the landing diameter on the quartz glass substrate was 100 μm.
In addition, Spectra SM-128 head was used as the inkjet head.
Further, the curvature radius of the rounding process was set to R1 = 25 μm and R2 = 50 μm, and other than that, the wiring pattern was formed in the same manner as in Example 1.

<Comparative Example 1>
A wiring pattern was formed in the same manner as in Example 1 except that the radius of curvature for rounding was R1 = 5 μm and R2 = 10 μm.

<Comparative example 2>
A wiring pattern was formed in the same manner as in Example 1 except that the rounding process was not performed.

< Reference example >
The volume of ink droplets to be applied was 50 pl, and the landing diameter on quartz glass was 100 μm.
In addition, Spectra SM-128 head was used as the inkjet head.
In addition, the radius of curvature of the rounding process was set to R1 = 15 μm and R2 = 25 μm, and a wiring pattern was formed in the same manner as in Example 1 except that.

  As understood from Table 1, in Examples 1 to 4, the line widths 1 and 2 of the pattern at the convex or concave bent portions are 100 μm, and the line width is narrower or wider than the other portions. Did not occur.

In contrast, in Comparative Example 1 in which the curvature radii R1 and R2 of the rounded portion are smaller than the ink landing diameter (D / 4), the line width of the pattern narrows and widens at the convex or concave bent portion.

  On the other hand, in Comparative Example 2 in which the rounded portion of the step was not rounded, disconnection occurred at the convex bent portion and the line width increased at the concave bent portion.

(A): Schematic explanatory diagram showing the state before applying the ink of the embodiment of the present invention (b): Schematic explanatory diagram showing the state before applying the ink of the embodiment (A): Schematic explanatory diagram showing pattern formation on a substrate having a step (b): Schematic explanatory diagram showing narrowing and widening of the line width of a wiring pattern in the prior art

Explanation of symbols

1 ... Glass substrate (application object)
2 ... rounded part 3 ... wiring pattern 10 ... inkjet head 11 ... ink

Claims (5)

When applying the ink across the bent portion of the step on the application object having a step, the ink application method of forming a rounded portion in advance in the bent portion of the step of the application object,
Landing diameter D of the ink and the curvature radius R of the rounded portion, to satisfy the relationship of R ≧ (D / 4), and the radius of curvature R of the rounded portion is at 100μm or less, impact diameter D of the ink An ink application method having a thickness of 50 μm or more and 100 μm or less .   The ink application method according to claim 1, wherein a rounded portion that curves in a direction across the bent portion of the step is formed.   The ink application method according to claim 1, wherein a rounded portion is formed in the convex bent portion of the step.   The ink application method according to claim 1, wherein a rounded portion is formed in the concave bent portion of the step.   The ink application method according to claim 1, wherein an ink containing metal fine particles is used as the ink, and a wiring pattern is formed on the application object.

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