JP5545802B2 - Conductive pattern manufacturing method - Google Patents

Description

The present invention relates to a conductive pattern manufacturing method for manufacturing a conductive pattern by firing.

  Conventionally, a photolithography method has been used to manufacture a metal conductive pattern as a wiring of an electronic circuit, an integrated circuit, or the like. This is a method in which a conductive layer made of metal is formed on a substrate, a so-called resist as a photosensitizer is applied, exposed and developed using a mask of a conductive pattern, and unnecessary conductive layer portions are removed. . In this method, there are many devices and processes required for formation, productivity may be lowered, and manufacturing costs are increased.

  Therefore, as disclosed in Japanese Patent Application Laid-Open No. 2002-134878, a method of manufacturing a conductive pattern by performing ink jet printing directly on a substrate using a conductive ink jet ink without using a mask, and Japanese Patent No. 4042497. Developed a method to produce a conductive pattern by firing by forming an ink receiving layer containing fine particles on a substrate without using a mask, performing inkjet printing using a conductive inkjet ink, and firing Has been.

JP 2002-134878 A Japanese Patent No. 4042497

  When ink jet printing is directly performed on a substrate, it may be blurred. In order to manufacture a conductive pattern set without bleeding, there is a method of forming an ink receiving layer on a substrate, and an ink receiving layer such as the above-mentioned Japanese Patent No. 4042497 has been developed, however, the manufactured conductive pattern The adhesion between the substrate and the substrate was not good.

  The problem to be solved by the present invention is to provide a film having good adhesion between a conductive pattern produced by baking and a substrate without being blurred even when inkjet printing is performed using a conductive inkjet ink. is there.

  In order to solve these problems, the ink solvent is absorbed by the swelling type ink receiving layer without containing fine particles and the bleeding is suppressed, and the silicon in the resin of the ink receiving layer adheres to the substrate. It is what improved.

The present invention does not contain fine particles, and is composed of at least an acrylic silicon resin and an ink solvent absorption resin. These resins can be formed into a film by drying at 25 ° C. to 150 ° C. with only one of the resins. An ink receptive layer coating liquid having a silicon content of 0.1 wt% to 0.5 wt% in a solid content ratio is applied to a polyimide substrate and dried at 25 ° C. to 150 ° C. An ink receiving layer is formed as a single layer, printed using conductive ink jet ink composed of conductive metal nanoparticles having an organic protective colloid, and baked at 200 ° C. or higher, an acrylic silicon resin or an ink solvent absorbing resin features of the organic component is volatilized first, followed by the metal nanoparticles are sintered, it together with the silicon is conductive pattern to improve the adhesion between the metal and the polyimide substrate A conductive pattern producing method of.

  According to the present invention, it is possible to provide an ink having good adhesion between a conductive pattern produced by baking and a substrate without being blurred even when ink-jet printing is performed using a conductive ink-jet ink.

It is explanatory drawing which showed the cross section which formed the ink receiving layer in the board | substrate. It is explanatory drawing which showed the printing part which carried out the inkjet printing in FIG. It is explanatory drawing which showed the electroconductive part formed by baking FIG.

  The ink receiving layer coating liquid of the present invention is applied to a substrate and dried at 25 ° C. to 150 ° C. to form an ink receiving layer as a single layer. It does not contain fine particles, absorbs the ink solvent by the swelling type ink receiving layer, suppresses bleeding, and improves the adhesion to the substrate by silicon in the resin of the ink receiving layer.

The substrate is not particularly limited as long as it meets the purpose of the conductive pattern. However, the substrate needs to be able to withstand baking at 200 ° C. or higher, and the material is preferably polyimide . The substrate can be formed into a film as long as it is a heat-resistant resin such as polyimide. In the case of a film, the ink receiving layer coating solution can be applied with a so-called coater.

  It is a swelling type ink receiving layer that absorbs the ink solvent, and is composed of at least an acrylic silicon resin and an ink solvent absorbing resin, and these resins can be dried at 25 ° C. to 150 ° C. with only one resin. It must be filmable and compatible with each other.

  The film formation is drying at 25 ° C. to 150 ° C. If the temperature is lower than this, the film formation may be difficult.

When they are mixed with each other and applied to a substrate to form a film, only one resin forms a film, so the ink-receiving layer formed by intricately intertwining the acrylic silicon resin network and the ink solvent absorbing resin network It becomes.

Here, it is considered that the network of the acrylic silicon resin mainly serves as a skeleton that maintains the ink receiving layer, and the network of the ink solvent absorbing resin mainly serves as a portion that swells and absorbs the ink solvent. As a result, even if the swelling type ink receiving layer does not contain fine particles, the ink receiving layer does not swell greatly even if it swells, and the ink solvent can be absorbed. In addition, since the ink is entangled in a complicated manner, the ink solvent is absorbed almost uniformly by the ink receiving layer wherever printing is performed, and bleeding is less likely to occur than the ink receiving layer containing fine particles.

  When the amount of the ink solvent absorbing resin is small, there is a tendency that the ink solvent is poorly absorbed and bleeds. In the solid content ratio, the ink solvent absorbing resin is preferably 50% by weight to 95% by weight, and more preferably 60% by weight to 90% by weight. The coating liquid may contain various additives.

  As the ink solvent absorbing resin, it can absorb the solvent of the conductive ink-jet ink, can be compatible with the acrylic silicon resin and applied to the substrate, and can be formed into a film by drying at 25 ° C. to 150 ° C. Anything is acceptable. For example, polyvinyl alcohol, polyvinyl pyrrolidone, melamine resin, urea resin, polyurethane resin, unsaturated polyester resin, maleic anhydride resin, styrene butadiene resin and the like having such properties can be used.

  When the solvent used for the ink is water, polyvinyl alcohol is preferable, and when the solvent is an organic solvent, a polyurethane resin is preferable.

Silicon is not a fine particle but an acrylic silicon resin obtained by modifying an acrylic resin with silicon. Since the silicon modified into such an acrylic resin is compatible with the ink solvent absorbing resin and applied to the polyimide substrate , the silicon is distributed evenly in the ink receiving layer. By baking this, the organic components of the acrylic silicon resin and ink solvent absorbing resin are volatilized first, followed by the sintering of the metal nanoparticles, and the silicon improves the adhesion between the metal and the polyimide substrate. It is what you are doing.

  The silicon content is preferably 0.1% by weight to 5.0% by weight in terms of solid content. Even if less or more than this, the effect which improves adhesiveness is not seen. When the amount is small, silicon cannot improve the adhesion between the metal and the substrate, but when the amount is large, the adhesion between the silicon becomes strong and the effect of improving the adhesion between the metal and the substrate is obtained. I guess it is not. The silicon content is more preferably 0.3% by weight to 0.5% by weight in terms of solid content.

  A conductive pattern manufacturing method using this receiving layer coating solution will be described with reference to the drawings.

  FIG. 1 is an explanatory view showing a cross section in which an ink receiving layer 2 is formed on a substrate 1. The ink receiving layer coating liquid is applied to the substrate 1 and formed into a film by drying at 25 ° C. to 150 ° C. to form the ink receiving layer 2 as a single layer.

  FIG. 2 is an explanatory diagram showing the printing unit 3 that has been ink-jet printed in FIG. The ink receiving layer 2 in FIG. 1 is ink-jet printed using a conductive ink-jet ink.

  The conductive inkjet ink is generally made of conductive metal nanoparticles having an organic protective colloid. By having an organic protective colloid, it can be dispersed in an ink solvent, and ink jet printing can be performed.

  As a discharge method of ink jet printing, a piezo method that discharges ink from a head nozzle by pressure using a piezoelectric element is suitable. In the thermal method, where heat is instantaneously applied to the ink and ink is ejected from the head nozzle, the ink itself and the organic protective colloid become unstable with respect to the heat, resulting in dot chipping, flying bends, bleeding, repelling, and firing. In some cases, the conductive pattern manufactured by the method has a problem such as a large variation in resistance value.

  The average particle diameter of the metal nanoparticles is 100 nm or less, and those having a size of about 10 nm are suitable. It has an organic protective colloid around the metal nanoparticles. Therefore, in the printing part 3 of the printed ink receiving layer 2, the ink solvent is absorbed by the ink receiving layer 2, but the metal nanoparticles remain on the surface of the receiving layer 2. Further, even if the ink solvent is absorbed, it is assumed that the organic protective colloid causes the accumulated thickness without bleeding.

  FIG. 3 is an explanatory view showing the conductive portion 4 formed by firing FIG. Firing at 200 ° C. or higher is performed. Since the drawing is a cross section, the conductive portions 4 are not adjacent to each other in the drawing, but the conductive portion 4 has a conductive pattern like a circuit as long as it is a plane viewed from above.

  As the temperature rises due to firing, the organic components are volatilized first, and then the metal nanoparticles are sintered to form a conductive pattern. Therefore, the volatilization of the organic protective colloid starts with the volatilization of the ink receiving layer 2, and not only the ink receiving layer 2 is volatilized directly from the portion without the printing unit 3, but the ink receiving layer 2 under the printing unit 3 is also a metal It is thought that it is volatilized through the gaps between the nanoparticles.

  In this manner, a conductive pattern using the ink receiving layer coating solution is manufactured.

  The ink receiving layer coating liquid does not contain fine particles and is composed of the following acrylic silicon resin and ink solvent absorbing resin. The solid content ratio is 40% by weight for acrylic silicon resin and 60% by weight for ink solvent absorbing resin. Then, water was used as a solvent for the solvent to prepare an ink-receiving layer coating solution. This ink receiving layer coating liquid was applied to a polyimide substrate and formed into a film by drying at 120 ° C. to form an ink receiving layer as a single layer.

  “Aquabrid 908” manufactured by Daicel Chemical Industries, Ltd. was used as the acrylic silicon resin. Since the silicon ratio of the acrylic silicon resin is 1%, the silicon content is 0.4% by weight in terms of solid content. As the ink solvent absorbing resin, polyvinyl alcohol “PVA-220E” manufactured by Kuraray Co., Ltd. was used.

  The acrylic silicone resin and ink solvent absorbing resin in this example can be formed into a film by diluting only one resin with water as a solvent and applying it to a polyimide substrate and drying at 120 ° C. It was. Moreover, even if these were mixed using water as a solvent, it was possible to achieve compatibility without layer separation.

  As the conductive inkjet ink, an aqueous ink, that is, a conductive metal nanoparticle having an organic protective colloid that can be dispersed in water is dispersed in water as a solvent. The following evaluation pattern was printed on the ink receiving layer with a piezo ink jet printer using this aqueous conductive ink jet ink. The evaluation pattern is a 10 × 10 dot pattern with a square of approximately 100 μm on a side at 100 μm intervals.

  As an evaluation of printability, an optical microscope was used to observe whether there was bleeding or repellency. As an evaluation result, it was confirmed that there was no blur or repellency, and that one side was a square of about 100 μm, and the result was OK.

  As an evaluation of adhesion, the ink receiving layer printed with the evaluation pattern was baked at 300 ° C. to volatilize the resin of the ink receiving layer, and a conductive pattern (evaluation pattern) was produced on the substrate. Cellotape (registered trademark) was attached to this evaluation pattern and peeled off in accordance with the adhesion test of JISK5600, and the number of squares having a side of approximately 100 μm was measured. It was also assumed that what was lifted off the substrate was peeled off. As an evaluation result, the number of peeling was 20 or less, and it was set as OK.

  An ink-receptive layer coating solution was prepared in the same manner as in Example 1 except that the ink solvent-absorbing resin was different from that in Example 1. A polyurethane resin “PUE930BS” manufactured by Murayama Chemical Laboratory Co., Ltd. was used as the ink solvent absorbing resin. This ink receiving layer coating liquid was applied to a polyimide substrate and formed into a film by drying at 120 ° C. to form an ink receiving layer as a single layer.

  The acrylic silicone resin and ink solvent absorbing resin in this example can be formed into a film by diluting only one resin with water as a solvent and applying it to a polyimide substrate and drying at 120 ° C. It was. Moreover, even if these were mixed using water as a solvent, it was possible to achieve compatibility without layer separation.

  As the conductive ink-jet ink, a solvent-based ink, that is, a conductive metal nanoparticle having an organic protective colloid that can be dispersed in an organic solvent is dispersed in an organic solvent as a solvent. The following evaluation pattern was printed on the ink receiving layer with a piezo ink jet printer using this solvent-based conductive ink jet ink. The evaluation pattern is a 10 × 10 dot pattern with a square of approximately 100 μm on a side at 100 μm intervals.

  As an evaluation of printability, an optical microscope was used to observe whether there was bleeding or repellency. As an evaluation result, it was confirmed that there was no blur or repellency, and that one side was a square of about 100 μm, and the result was OK.

  As an evaluation of adhesion, the ink receiving layer printed with the evaluation pattern was baked at 300 ° C. to volatilize the resin of the ink receiving layer, and a conductive pattern (evaluation pattern) was produced on the substrate. Cellotape (registered trademark) was attached to this evaluation pattern and peeled off in accordance with the adhesion test of JISK5600, and the number of squares having a side of approximately 100 μm was measured. It was also assumed that what was lifted off the substrate was peeled off. As an evaluation result, the number of peeling was 20 or less, and it was set as OK.

  The conductive inkjet ink is composed of silver nanoparticles having an organic protective colloid and a solvent. As the silver nanoparticles having an organic protective colloid, “NAG-09” manufactured by Daiken Chemical Industry Co., Ltd., whose solvent was changed to nonanol was used. In addition, Isopar E was added as a solvent in order to obtain suitability as an inkjet ink. This is a conductive inkjet ink in which the mixing ratio of silver nanoparticles having an organic protective colloid, nonanol, and Isopar E is 27% by weight, 27% by weight, and 46% by weight.

  The following evaluation pattern was printed on the ink receiving layer of Example 2 capable of absorbing these solvents with a piezoelectric inkjet printer using this conductive inkjet ink. The evaluation pattern is a 10 × 10 dot pattern with a square of approximately 100 μm on a side at 100 μm intervals.

  As an evaluation of printability, an optical microscope was used to observe whether there was bleeding or repellency. As an evaluation result, it was confirmed that there was no blur or repellency, and that one side was a square of about 100 μm, and the result was OK.

  As an evaluation of adhesion, the ink receiving layer printed with the evaluation pattern was baked at 300 ° C. to volatilize the resin of the ink receiving layer, and a conductive pattern (evaluation pattern) was produced on the substrate. Cellotape (registered trademark) was attached to this evaluation pattern and peeled off in accordance with the adhesion test of JISK5600, and the number of squares having a side of approximately 100 μm was measured. It was also assumed that what was lifted off the substrate was peeled off. As an evaluation result, the number of peeling was 20 or less, and it was set as OK.

(Comparative Example 1)
An ink receiving layer coating solution was prepared in the same manner as in Example 1 except that the solid content ratio of the resin was different from that in Example 1. The solid content ratio was 60% by weight for the acrylic silicon resin and 40% by weight for the ink solvent absorbing resin. Since the silicon ratio of the acrylic silicon resin is 1%, the silicon content is 0.6% by weight in terms of solid content. This ink receiving layer coating liquid was applied to a polyimide substrate and formed into a film by drying at 120 ° C. to form an ink receiving layer as a single layer.

  In the same manner as in Example 1, an evaluation pattern was printed on the ink receiving layer using a water-based conductive inkjet ink and evaluated. As a result of evaluation of printability, bleeding was observed, and as a result of evaluation of adhesion, the number of peeling was more than 20, and it was not determined as OK.

(Comparative Example 2)
An ink receiving layer coating solution was prepared in the same manner as in Example 2 except that the solid content ratio of the resin was different from that in Example 2. The solid content ratio was 60% by weight for the acrylic silicon resin and 40% by weight for the ink solvent absorbing resin. Since the silicon ratio of the acrylic silicon resin is 1%, the silicon content is 0.6% by weight in terms of solid content. This ink receiving layer coating liquid was applied to a polyimide substrate and formed into a film by drying at 120 ° C. to form an ink receiving layer as a single layer.

  In the same manner as in Example 2, an evaluation pattern was printed on the ink receiving layer using a solvent-based conductive inkjet ink and evaluated. The solvent-based conductive inkjet ink used in Example 3 was used. As a result of evaluation of printability, bleeding was observed, and as a result of evaluation of adhesion, the number of peeling was more than 20, and it was not determined as OK.

DESCRIPTION OF SYMBOLS 1 Board | substrate 2 Ink receiving layer 3 Printing part 4 Conductive part

Claims (1)

Containing at least acrylic silicon resin and ink solvent absorbing resin, which does not contain fine particles, and these resins can be formed into a film by drying at 25 ° C. to 150 ° C. with only one resin and compatible with each other. The ink receiving layer coating liquid having a silicon content of 0.1 wt% to 0.5 wt% in solid content ratio is applied to a polyimide substrate , and the ink receiving layer is dried at 25 ° C. to 150 ° C. Is formed using a single layer, printed using a conductive inkjet ink composed of conductive metal nanoparticles having an organic protective colloid, and an organic component such as an acrylic silicon resin or an ink solvent absorbing resin is formed by baking at 200 ° C. or higher. and volatilized earlier, conductive that subsequently the metal nanoparticles are sintered, silicon therewith is characterized by comprising a conductive pattern to improve the adhesion between the metal and the polyimide substrate Turn manufacturing method.

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