TWI611016B - Screen cleaning solutions and methods of using the same - Google Patents

Abstract

A screen cleaning solution comprising: a basic compound and a resin stripper, and the screen cleaning solution has a pH of between 10 and 14. By using a basic compound and a resin stripper to react with the resin layer of the screen, the screen cleaning solution of the present invention is used as a regenerated screen, which can effectively remove the resin layer of the screen and effectively prevent the metal of the screen. Oxidation and dark reaction occur in the mesh to improve the yield and quality of screen printing.

Description

Screen cleaning solution and using method thereof

The present invention relates to a cleaning solution and a method of using the same, and more particularly to a screen cleaning solution for printing and a method of using the same.

With the multiplex and miniaturization of electronic devices, circuit boards of electronic devices must be equipped with high-density electronic components and wiring. Metal screen printing has been applied to the process of such circuit substrates to meet the requirements of miniature electronic components and wiring. Claim. The process of the metal screen printing electronic circuit comprises the following steps: first, coating a photosensitive emulsion (for example, an acrylic resin) on a metal mesh having a warp and weft structure; secondly, exposing and developing the emulsion to form a screen pattern (ie, developing) Thereafter, the emulsion layer having the micronized ink permeation holes is pressed; then, the conductive ink is applied by pressure coating, and the conductive ink is transmitted through the ink permeation holes of the screen pattern to print the conductive ink on the circuit substrate. If the screen pattern is poorly formed or damaged after use, since it is impossible to regenerate the patterned emulsion layer and reproduce the screen, it is necessary to remove the patterned emulsion layer with a cleaning solution, and then re-make the screen according to the above process ( Recycled version).

The emulsion contains a photoacid generating group (for example, a diazo group), so that the emulsion can be cured by exposure, and the photoacid generating group contained in the emulsion easily precipitates iron ions of the metal mesh, and the photoacid generating group further The iron ion reacts to form a film (dark reaction), which affects the degree of bonding between the emulsion and the metal mesh, resulting in poor pattern formation. Most of the commercially available screen cleaning solutions are neutral or acidic cleaning solutions. The main cleaning method is to remove them with a soft brushing tool (eg sponge). A patterned emulsion layer. For high-precision metal mesh, the commercially available screen cleaning solution and its cleaning method cannot effectively remove the residue of the emulsion attached to the warp and weft of the metal mesh or the mesh.

Fig. 1A is a top plan view of a poorly cleaned metal mesh, and Fig. 1B is a side view of the warp and weft interlaced portion in Fig. 1A. As shown in FIG. 1A, the metal mesh 1 has a warp thread 11, a weft thread 12, a warp and weft interlacing portion 13 and a mesh 14, on which a dark reaction film 15 is formed on the surface of the warp 11 or the weft 12 on the poorly cleaned metal mesh 1. The photographic emulsion 2 is easily left in the warp and weft interlaced portion 13 and the high-precision mesh 14, and in particular, as shown in Fig. 1B, the cleaning method of the commercially available cleaning liquid cannot penetrate the gap between the warp and weft interlacing portions 13 of the warp threads 11 and the weft threads 12. , causing the emulsion 2 to remain therein.

Therefore, how to solve the above problems and effectively clean the metal mesh of the screen to improve the yield and quality of the screen printing is to develop the main purpose of the present invention.

To achieve the above object, the present invention provides a screen cleaning solution comprising: a basic compound and a resin stripper having a pH of from 10 to 14 in the screen cleaning solution.

In one embodiment, the basic compound is selected from the group consisting of an alkali metal hydroxide, an alkaline earth metal hydroxide, ammonium hydroxide, or a combination thereof.

In one embodiment, the resin stripper is selected from the group consisting of ketones, ethers, aliphatics, aromatics, or combinations thereof.

In one embodiment, the screen cleaning solution of the present invention comprises: a surfactant and a thickener.

In one embodiment, the basic compound is not more than 45% by weight, the resin stripper is not more than 1% by weight, and the surfactant is not more than 5% by weight, based on the total weight of the screen cleaning solution. The thickener is not more than 1% by weight, and the balance is water.

In one embodiment, the surfactant is selected from the group consisting of polyoxyethylene or polyol. a surfactant; the thickener is selected from the group consisting of inorganic salts, fatty alcohols, fatty acids, alkanolamines, ethers, amine oxides, soaps, inorganic celluloses, polyacryls, polyurethanes, Polysaccharides, or polyoxyethylenes.

In one embodiment, the viscosity of the screen cleaning solution is not less than 400 C.P.S.

In order to achieve the above object, the present invention provides a method for using a screen cleaning solution, comprising: coating the screen cleaning solution to a screen comprising a resin layer and a metal mesh, and reacting the screen cleaning solution with the resin layer; And removing the above-mentioned screen cleaning liquid and resin layer after the reaction.

In one embodiment, the screen cleaning solution after the reaction and the resin layer are removed by water containing a surfactant.

In one embodiment, the method of the present invention comprises: restoring the screen of the screen cleaning solution coated above.

By using a basic compound and a resin stripper to react with the resin layer of the screen, the screen cleaning solution of the present invention is used as a regenerated screen, which can effectively remove the resin layer of the screen and effectively prevent the metal of the screen. The mesh is oxidized and dark reacted and reduces the destructive effect of the lotion on the metal mesh, thereby improving the yield and quality of the screen printing.

1‧‧‧Metal mesh

2‧‧‧Photosensitive emulsion

11‧‧‧ warp

12‧‧‧Weft

13‧‧‧ warp and weft

14‧‧‧Net

15‧‧‧Dark reaction film

Fig. 1A is a top plan view of a poorly cleaned metal mesh, and Fig. 1B is a side view of the warp and weft interlaced portion in Fig. 1A.

The embodiments of the present invention are described in the following by means of specific embodiments, and those skilled in the art can readily understand the advantages and functions of the present invention from the disclosure. It is worth noting that in order to clearly demonstrate the main features of the present invention, the first figure The relative relationship between the main elements is only shown in a schematic manner, and is not drawn according to the actual size. Therefore, the thickness, size, shape, arrangement, arrangement and the like of the main elements in the drawings are only for reference, and are not intended to limit the present invention. range.

A screen cleaning solution comprising: a basic compound and a resin stripper, the basic compound being selected from the group consisting of an alkali metal hydroxide, an alkaline earth metal hydroxide, ammonium hydroxide, or a combination thereof, for example: sodium hydroxide (NaOH) , potassium hydroxide (KOH), ammonia (NH ₄ OH), etc., so that the screen cleaning solution has a pH of between 10 and 14, for example, pH 12 to 14, and for example, pH 13 to 14. The resin stripper may be selected from a mixture of toluene and cyclohexanone N-methylpyrrolidone (NMP), wherein toluene accounts for no more than 1% by weight.

In detail, the resin material applied to the metal mesh (for example, a resin containing a diazo group) is cured to be a water resistant resin, which may be represented by RCOOR', wherein R and R' represent an organic group). The mechanism for cleaning the water resistant resin by the screen cleaning liquid of the present invention comprises: a resin stripping agent swells the water resistant resin RCOOR'; a basic compound (M ⁺ OH ^- , wherein M represents an alkali metal ion, an alkaline earth metal ion, or an ammonium ion) It reacts with the swollen water-resistant resin RCOOR' to form water-soluble organic substances RCOO ^- M ⁺ and R'OH (eluate). Thereafter, the eluate on the metal mesh is completely removed by rinsing with an aqueous solution.

Further, if the iron ions of the metal mesh are precipitated to form a dark reaction film (iron compound) with the photoacid generating group of the resin material, the metal ion M ^{+ of the} basic compound can replace the iron ions of the dark reaction film to produce water solubility. Metal compounds and iron ions. Therefore, the screen cleaning liquid of the present invention can effectively remove the water resistant resin and the dark reaction film on the metal mesh, prevent the water resistant resin and the dark reaction film from remaining on the metal mesh, and improve the efficiency and yield of the regenerated screen. Improve the accuracy and quality of screen printing.

In addition, at present, the screen of the printed electronic circuit uses a composite mesh of a metal mesh cloth and a Tedron mesh cloth, wherein the printed pattern area uses a metal mesh cloth, and is used for laying a metal mesh cloth. In the surrounding area, Tedron mesh is used to reduce the manufacturing cost of the screen. Considering the influence of the basic compound on the Tedron mesh (for example, the destruction of the polymer structure leads to a decrease in the strength and the decrease in the number of uses), in the case of cleaning the composite mesh, the screen cleaning solution of the present invention may further comprise: Surfactant and thickener.

Specifically, the surfactant may be selected from polyoxyethylene ethers, and the thickener may be selected from a thickener of the acrylic body. The addition of a surfactant enhances the cleaning power of the screen cleaning solution and the water solubility of the eluate. Adding a thickener can increase the viscosity of the screen cleaning solution, and the screen cleaning solution applied to the metal mesh area is maintained in the metal mesh area to clean the patterned resin layer (ie, the printing screen pattern) without overflowing to the periphery. The Tedron mesh area ensures the number of times the composite mesh is used. The viscosity of the screen cleaning solution containing the thickener is about 400 to 20000 C.P.S. In such a screen cleaning solution, based on the total weight of the screen cleaning solution, the basic compound is not more than 45% by weight, the resin stripping agent is not more than 1% by weight, the surfactant is not more than 5% by weight, thickening The agent is not more than 1% by weight, and the balance is water.

According to the characteristics of the screen cleaning liquid of the present invention, the present invention provides a method for using a screen cleaning solution, comprising: coating the screen cleaning liquid of the present invention to a screen comprising a resin layer and a metal mesh, and making the screen cleaning solution The reaction with the resin layer; and removal of the screen cleaning solution and the resin layer after the reaction.

Specifically, the method of coating the screen cleaning liquid may be a doctor blade coating or a slit coating, and the screen cleaning liquid and the resin layer after the reaction may be removed using water containing a surfactant. In a specific case (for example, a thicker patterned resin layer or more dark reaction film), the method of the present invention may further comprise: standing the screen of the coated screen cleaning solution for a period of time, for example: 1 to 60 For example, 5 to 30 minutes, the screen cleaning solution is sufficiently reacted with the resin layer to form a water-soluble eluate.

The screen cleaning solution of the present invention and its user are described below by way of specific embodiments. law.

Example formulation and comparative example formulation

Metal mesh specifications: 360 mesh, wire diameter 16um, yarn thickness 18um.

The screen cleaning solutions of the examples and the comparative examples were diluted to an appropriate viscosity, and then applied to a plurality of screens on which a photosensitive emulsion was formed; after standing for 10 minutes, the screen was washed with water. The metal screen which was cleaned using the screen cleaning liquids of the examples and the comparative examples was re-formed into a screen (recycled screen) to test the line width yield and the screen reproduction rate of the printing pattern. The test results are shown in Table 2.

As shown in Table 2, using the regenerated screen of the screen cleaning solution of the present invention, the yield of the printed pattern line width (the comparison object can be a new screen or a regenerated screen of the comparative example) can reach 98%, the regeneration rate It can reach 95%, and the stainless steel mesh breakage rate is less than 10%. It can be seen from the test results that the present invention reacts with the resin layer of the screen by the basic compound and the resin stripper, and uses the screen cleaning liquid of the invention to prepare the recycled screen, in addition to effectively removing the resin layer of the screen. It can effectively prevent the dark reaction of the metal mesh of the screen and reduce the destructive effect of the detergent on the steel mesh, thereby improving the yield and quality of the screen printing.

The above-described embodiments are merely illustrative of the principles of the invention and its effects, and are not intended to limit the invention. Modifications and variations of the above-described embodiments can be made by those skilled in the art without departing from the spirit and scope of the invention. Therefore, all equivalent modifications and changes may be made without departing from the spirit and scope of the invention as disclosed in the appended claims.

Claims (7)

A screen cleaning solution comprising: a basic compound; a surfactant; a thickener; and a resin stripper having a pH of between 10 and 14 and a viscosity of the screen cleaning solution Less than 400C.PS. The screen cleaning solution according to claim 1, wherein the basic compound is selected from the group consisting of an alkali metal hydroxide, an alkaline earth metal hydroxide, ammonium hydroxide, or a combination thereof. The screen cleaning solution according to claim 1, wherein the resin release agent is selected from the group consisting of ketones, ethers, aliphatics, aromatics, or a combination thereof. The screen cleaning solution according to claim 1, wherein the basic compound is not more than 45% by weight based on the total weight of the screen cleaning solution, and the resin stripping agent is not more than 1% by weight, the interface The active agent is not more than 5% by weight, the thickener is not more than 1% by weight, and the balance is water. The screen cleaning solution according to claim 1, wherein the surfactant is selected from the group consisting of polyoxyethylene or polyol surfactant; the thickener is selected from the group consisting of inorganic salts, fatty alcohols, and fatty acids. , alkanolamines, ethers, amine oxides, soaps, inorganic cellulose, polyacrylic acid, polyurethanes, polysaccharides or polyoxyethylenes. A method for using a screen cleaning solution, comprising: Coating the screen cleaning solution according to claim 1 of the patent application to a screen comprising a resin layer and a metal mesh, reacting the screen cleaning solution with the resin layer; and removing the reaction with water containing a surfactant The screen cleaning solution and the resin layer. The method for using a screen cleaning solution according to Item 6 of the patent application, wherein the method comprises: resting the screen of the screen cleaning solution.