JPH0241189B2 - - Google Patents

Description

[Detailed description of the invention]

INDUSTRIAL APPLICATION FIELD The present invention relates to a curved surface printing method for printing a thick film paste on the edge of a substrate of an electronic component such as a hybrid integrated circuit. Structure of conventional example and its problems As a conventional curved surface printing method, the tacho printing method (also called tampo printing) is often used for printing on curved surfaces such as synthetic resins. FIG. 1 shows the principle of the octopus printing method. 1 is a transfer material called octopus or tampo, which is made of rubber or gelatin. 2 is a concave plate, 3 is ink, and 4 is an object to be printed. To explain the printing operation in the above configuration, first, ink 3 is supplied to the concave plate 2 as shown in FIG. 1a. Next, as shown in FIG. 1b, the transfer body 1 is lowered and pressed against the concave plate 2. As a result, Figure 1c
As shown in FIG. 1, when the transfer body 1 rises, the ink 3 adheres to the transfer body 1. Next, as shown in FIG. 1d, the transfer body 1 is moved onto the printing object 4 and is pressed against the printing object 4. Thereafter, as shown in FIG. 1e, when the transfer body 1 rises, the ink 3 adheres to the printing object 4,
Printing is complete. However, the above configuration utilizes the shape change due to the elasticity of the transfer body 1, and therefore has the disadvantages of poor printing accuracy, thin printing thickness, and inability to print on convex curved surfaces with small curvature radius. Purpose of the Invention In view of the above-mentioned drawbacks, the present invention provides the following:
The present invention provides a method for printing a thick film paste on a curved surface with high precision onto the edge of a substrate of an electronic component such as a hybrid integrated circuit. Structure of the Invention The present invention provides a curved surface printing method for printing on the curved surface of a plate-shaped printing object having a curved surface, which includes a step of printing a thick film paste on a thin silicone rubber plate, and a curved surface of the plate-shaped printing object. arranging the plate-shaped printing object above the thick-film paste printing side of the thin silicone rubber so as to face the thick film paste; and arranging the plate-shaped printing object of the thin silicone rubber. Two parallel rollers, which are located on the opposite side to the surface opposite to the thin plate-shaped silicone rubber and are arranged to face the thin plate-shaped silicone rubber, are pushed upward so that the thin-plate silicone rubber grips the plate-shaped printing object, and the thin plate The curved surface printing method includes the step of printing the thick film paste on the curved surface of the plate-like printing object by placing the silicone rubber along the plate-like printing object with the roller, so that it is perpendicular to the curved surface. In addition, since it uses the flexibility of the thin rubber sheet rather than its elasticity, it can transfer with little elastic deformation in the directions parallel to and perpendicular to the transfer surface of the transfer medium. Since the force applied to the thick film paste is reduced, deformation is reduced, and it is possible to improve printing accuracy, increase the printing thickness, and improve adhesion to convex curved surfaces with a small radius of curvature. DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG. FIG. 2 shows an embodiment of the invention. In FIG. 2, 5 is a thin plate of silicone rubber, 6 is a metal mask, 7 is a squeegee, 8 is a thick film paste, 9 is a plate-shaped printing object having a convex curved surface portion,
10 is a roller, and 11 is a holding part, which holds two rollers 10 and holds a plate-shaped printing object 9 between the two rollers 10 with a thin silicone rubber 5 interposed therebetween. Move the roller 10 up and down. To explain the printing transfer operation in the above configuration, first, as shown in FIG.
print. Remove excess paste with squeegee 7. Next, as shown in FIG. 2b, after fixing the plate-shaped printing object 9 on the thin silicone rubber 5, two rollers 1 are placed at a predetermined interval as shown in FIG. 2c.
0, the thin silicone rubber 5 is aligned with the plate-like printing object 9. After that, as shown in FIG. 2d, the roller 1
When the value is lowered to 0, the thick film paste 8 printed on the thin silicone rubber plate 5 adheres to the plate-shaped printing object 9, and printing is completed. As described above, in the above embodiment, by using the thin plate-like silicone rubber 5 as the transfer medium, it is possible to print on the plate-like printing object 9 with a small curvature and large irregularities. Further, since the thick film paste 8 is pressed with a weak and uniform pressure, it can be printed thickly and the thickness is also uniform. Furthermore, since the transfer medium is elastically deformed only in a portion along the curved surface, it hardly deforms in the vertical direction in FIG. 2, allowing highly accurate printing. In the above example, silicone rubber was used as the thin rubber plate to take advantage of the fact that silicone rubber has high water absorption and solvent absorption properties, and the printing paste on the surface in contact with the thin silicone rubber dried slightly. This has the effect that it becomes easier to peel off from the silicone rubber and that the thick film paste is less likely to lose its shape. In addition, since the thick film paste that does not come into contact with the thin silicone rubber does not dry easily, it remains sticky and can be completely transferred to the printing target. The effect of using this silicone rubber has been demonstrated through transfer experiments using thin rubber sheets of various materials. As an example, the table below shows the results of a transfer experiment using four types of thin rubber sheets, including silicone rubber, in the case of a paste whose main component is glass (paste printing thickness: 60 μm). In the table below, the drying time indicates the time from when the paste is applied to the thin rubber sheet until it is transferred to the object to be printed. As is clear from the table below, when silicone rubber was used as the thin rubber material, a good transfer condition was obtained with a drying time of 20 to 60 seconds, but with other rubber materials, a short drying time Insufficient drying may cause the paste to stick to the object to be printed, and if the drying time is too long, cracks may occur in the paste due to excessive drying, making it impossible to obtain a good printing condition. The above-mentioned differences in printing conditions depending on the rubber materials are considered to be due to the differences in water absorption and solvent absorption of each rubber material. That is, it can be said that the water absorption and solvent absorption properties of silicone rubber are suitable for paste transfer. In the above embodiment, a metal mask was used to apply the thick film paste 8 to the thin silicone rubber 5, but screen printing, relief printing, concave printing, or planar printing may be used.

[Table] Effects of the Invention As described above, in the present invention, by using a thin plate-like silicone rubber as a transfer medium, the paste can be properly dried due to the water absorption and solvent absorption properties of the silicone rubber. By using a roller to align the thin silicone rubber to the curved surface to be printed, the thin silicone rubber is less likely to be stretched in the longitudinal direction, and it can be evenly adhered to the curved surface with almost no force applied in the direction perpendicular to it. The thick film paste can be transferred with almost no force applied to the paste itself, both in directions parallel to and perpendicular to the curved surface, so there is no need to apply any force to the thick film paste itself. It is possible to easily obtain a good transfer condition without cracking of the paste, which increases the printing film thickness and improves uniformity, and also provides good adhesion to convex curved surfaces with a small radius of curvature, such as the edges of the substrate. It has great practical effects, such as being able to print thick film pastes.

[Brief explanation of drawings]

1A to 1E are work flow diagrams of conventional tacho (tampo) printing, and FIGS. 2A to 2D are work flow diagrams of an embodiment of the present invention. 5...Thin silicon rubber, 8...Thick film paste, 9...Target for plate printing.

Claims (1)

[Claims] 1. In a curved surface printing method for printing on a curved surface of a plate-shaped printing object having a convex curved surface part, a step of printing a thick film paste on a thin plate-shaped silicone rubber, and a step of printing a thick film paste on a thin plate-shaped silicone rubber, arranging the plate-shaped printing object above the thick film paste printing surface side of the thin silicone rubber plate so as to face the paste; is located on the opposite surface and is arranged to face the thin silicone rubber.
The parallel rollers of the book are pushed upward so that the thin silicone rubber grips the plate-like printing object, and the thin silicone rubber is made to run along the plate-like printing object with the rollers, so that the thick film A curved surface printing method comprising the step of printing a paste on a curved surface portion of the plate-shaped printing object.