METHOD FOR INK JET PRINTING OF A SUBSTRATE

Abstract

A method for ink jet printing of a substrate, as well as an ink jet printed layer. To provide a method for ink jet printing of a substrate that is particularly fast and energy-conserving and does not require any systems with high procurement and operating costs, initially a substrate is supplied, which is then coated with a layer of a print medium on at least one surface. A labeling of the substrate is carried out by applying the same print medium to result in a different color shade of the printed layer.

Claims

1. A method for ink jet printing of a substrate comprising the steps of: supplying a substrate, coating at least one surface of the substrate with a layer of a print medium, wherein a labeling of the substrate is carried out by applying the same print medium to result in a different color shade of the printed layer.

2. The method for producing a labeled printed circuit board according to claim 1, wherein the coating and the labeling are simultaneous.

3. The method for producing a labeled printed circuit board according to claim 1, wherein the at least one different color shade of the labeling is achieved by a different layer thickness, or a different color density of the applied layer of the print medium.

4. The method for producing a labeled printed circuit board according to claim 1, wherein the coating and labeling are both carried out using an inkjet printing method.

5. The method for producing a labeled printed circuit board according to claim 1, wherein the different color shades of the coating and the labeling are achieved by a local variation in the inkjet print points per area.

6. The method for producing a labeled printed circuit board according to claim 1, wherein a functional laquer is used to produce the layer of print medium.

7. The method for producing a labeled printed circuit board according to claim 1, wherein the layer of the print medium forms the outer surface of the substrate, and/or no additional labeling is applied on the layer of the print medium.

8. The method for producing a labeled printed circuit board according to claim 1, wherein the labeling is produced or reinforced by a second application of the same print medium of the layer.

9. The method for producing a labeled printed circuit board according to claim 1, wherein an individual labeling is carried out for each individual substrate to be coated and to be labeled.

10. The method for producing a labeled printed circuit board according to claim 1, wherein labeling occurs at an even and/or unchanged printing speed.

11. A printed substrate, comprising: at least one surface of a substrate, an at least partial surface coating with a layer of print medium on the surface of the substrate, and a labeling of the substrate carried out by applying the same print medium to result in a different color shade of the printed layer.

Description

[0026] An exemplary embodiment of the method according to the invention is explained in greater detail below with reference to the drawing. In the FIGURE:

[0027] FIG. 1 shows a schematic sectional view of a coated and labeled printed circuit board.

[0028] A labeled printed circuit board 1 shown in FIG. 1 is produced according to an embodiment of the method according to the invention. To accomplish this, a substrate 3 consisting of fiber-reinforced plastic and coated with copper conductive tracks 2 is fed to an inkjet printing system. The conductive tracks 2 are produced by illumination and subsequent etching.

[0029] In the inkjet printing system, there is a substantially extensive coating of the surface of the substrate 3 as well as the conductive tracks 2 with a functional solder resist 4, in particular based on epoxy resin, to ensure a precise soldered connection when populating the printed circuit board 1 with electronic components and subsequently soldering the components, and to avoid the formation of undesirable solder bridges. Moreover, the solder resist 4 increases the electric strength, protects the conductive tracks 2 from corrosion, and reduces the consumption of tin solder while soldering the electronic components.

[0030] The coating with the functional solder resist 4 is done nearly of the entire surface, wherein the lands 7 on the surface of the conductive tracks 2 are omitted to allow components to be soldered.

[0031] Moreover, a labeling of the substrate 3 is also carried out simultaneous to the extensive coating by means of the inkjet printing system. To accomplish this, a solder resist 4 is used that cures colored and partially transparent. At the positions at which labeling is to occur on the surface of the substrate 3, the solder resist 4 is applied with a high printing density during the extensive coating so that a contrast in color results in comparison to the other coated surface. By means of different print densities in individual regions in comparison to the functional solder resist layer 4, it is possible to produce labelings with darker color shades 5, 6.

[0032] These labelings can be both batch or lot IDs, as well as comprise any characters, trademarks or other information such as barcodes or QR codes. Given the greater layer thickness of the regions labeled with a higher print density, a quite visually apparent and haptically perceptible labeling results with a darker color shade 5, 6.