METHOD FOR THE SELECTIVE ETCHING OF A LAYER OR A STACK OF LAYERS ON A GLASS SUBSTRATE

Abstract

A process for depositing on a glass substrate a mineral functional layer or stack, includes depositing on the substrate a laser-crosslinkable organic photosensitive resin liquid composition, locally crosslinking the resin by a laser, removing the non-crosslinked liquid composition, depositing on the substrate thus coated a mineral functional layer or stack, and then performing combustion of the crosslinked solid resin via a heat treatment, completing its removal and that of the mineral layer or stack via a mechanical action, so as to obtain the mineral layer or stack in a pattern corresponding to the negative of that made with the crosslinked solid resin.

Claims

1. A process for depositing on a glass substrate an essentially mineral functional layer or stack of layers, the process comprising: depositing on the glass substrate a precursor liquid composition of a laser-crosslinkable essentially organic photosensitive resin, locally crosslinking the resin by a laser, removing the non-crosslinked liquid composition, depositing on the glass substrate thus coated an essentially mineral functional layer or stack of layers, and then subjecting an assembly formed by the glass substrate thus coated and the essentially mineral functional layer or stack of layers to a heat treatment so as to effect combustion of the crosslinked solid resin, completing a removal of said resin and of the essentially mineral functional layer or stack of layers covering it by a mechanical action, the heat treatment not being necessary if the width of the crosslinked solid resin pattern is at most equal to 40 μm, so as to obtain the essentially mineral functional layer or stack of layers in a pattern corresponding to a negative of that made with the crosslinked solid resin.

2. The process as claimed in claim 1, wherein the deposition of the precursor liquid composition of a photosensitive resin is performed using a Mayer rod, a film spreader, a spin coater, or by dipping.

3. The process as claimed in claim 2, wherein the precursor liquid composition of a photosensitive resin is usable for photolithography and comprises an epoxy resin in a solvent or any organic material that is crosslinkable under ultraviolet, infrared or visible radiation, alone or as a mixture of several thereof.

4. The process as claimed in claim 1, wherein the precursor liquid composition of a photosensitive resin is deposited on the substrate in a thickness of between 1 and 40 μm.

5. The process as claimed in claim 1, wherein the crosslinked solid resin pattern comprises lines with widths of between 5 and 20 μm.

6. The process as claimed in claim 1, wherein, to remove the non-crosslinked liquid composition, the coated glass substrate is immersed in a good solvent for the non-crosslinked liquid composition, it is then extracted therefrom, good solvent is then sprayed delicately onto the substrate, a surface of the glass substrate is then washed by delicately spraying with a solvent to remove the good solvent therefrom and in the vicinity of the crosslinked solid resin pattern, and the glass substrate and the crosslinked solid resin pattern are then dried with a stream of gas.

7. The process as claimed in claim 1, wherein the essentially mineral functional layer or stack of layers is formed by a process of physical vapor deposition (PVD) under vacuum, evaporation or plasma-enhanced chemical vapor deposition (PECVD) or via a liquid route.

8. The process as claimed in claim 7, wherein the essentially mineral functional layer or stack of layers is constituted of Ag, transparent conductive oxide (TCO) Al, Nb, Cu, Au, a compound of Si and N such as Si.sub.3N.sub.4, an afferent dielectric stack, alone or as a combination of several thereof.

9. The process as claimed in claim 1, wherein a thickness of the essentially mineral functional layer or stack of layers is at least 10 times smaller than that of the crosslinked solid resin pattern.

10. The process as claimed in claim 1, wherein the heat treatment forms part of a thermal tempering of the glass substrate.

11. The process as claimed in claim 1, wherein the heat treatment forms part of a bending of the glass substrate.

12. The process as claimed in claim 11, wherein the bending is performed by pressing.

13. The process as claimed in claim 1, wherein, after the deposition of the essentially mineral functional layer or stack of layers, at least one essentially organic photosensitive resin—essentially mineral functional layer or stack of layers sequence is deposited again.

14. A glass substrate coated with at least one sequence comprising: a solid essentially organic photosensitive resin which is crosslinked, over a part but not all of its surface, in accordance with a pattern comprising lines with widths of between 5 and 100 μm and heights of between 1 and 40 μm; covered with an essentially mineral functional layer or stack of layers with thicknesses at most equal to 300 nm, and which extends substantially over the entire surface of the substrate.

15. A method comprising utilizing a glazing with an essentially mineral functional layer or stack of layers, obtained via a process as claimed in claim 1, as a functional glazing with decreased transmission attenuation of waves with frequencies of between 0.4 and 5 GHz.

16. The process as claimed in claim 1, wherein the resin and the essentially mineral functional layer or stack of layers are removed by wiping with a cloth and/or blowing with gas and/or washing.

17. The process as claimed in claim 3, wherein the photosensitive resin comprises cyclopentanone, a monomer and/or oligomer of acrylate, epoxyacrylate, polyester acrylate, polyurethane acrylate, polyvinylpyrrolidone+EDTA composition, polyamide, polyvinyl butyral, positive photosensitive resin of diazonaphthoquinone-novolac type.

18. The process as claimed in claim 6, wherein the solvent is isopropanol and the stream of gas is nitrogen or air.

19. The process as claimed in claim 7, wherein the essentially mineral functional layer or stack of layers is formed by cathode-enhanced magnetron sputtering.

20. The process as claimed in claim 9, wherein the thickness of the essentially mineral functional layer or stack of layers is at most equal to 300 nm.

Description

EXAMPLE 1

[0050] A uniform thickness of a precursor liquid composition of an organic photosensitive resin, sold by the company MicroChem Corp under the registered brand name MicroChem® SU-8 2015, is applied by spin coating to a 15 cm×15 cm glass substrate 4 mm thick, sold by the company Saint-Gobain Glass under the registered brand name Planiclear®.

[0051] This liquid composition contains, as mass percentages: [0052] epoxy resin (CAS No. 28906-96-9): 3-75% [0053] cyclopentanone (CAS No. 120-92-3): 23-96% [0054] hexafluoroantimonate salt (CAS No. 71449-78-0): 0.3-5% [0055] propylene carbonate (CAS No. 108-32-7): 0.3-5% [0056] triarylsulfonium salt (CAS No. 89452-37-9): 0.3-5%

[0057] A uniform liquid thickness of 21 μm is deposited at a spin-coating spin speed of 2000 rpm. A spin coater machine of registered brand name Semiconductor Production Systems Europe® (SPS) sold under the reference SPIN150 is used.

[0058] The resin is crosslinked locally using a laser sold under the registered brand name Trumpf®, TruMark Station 5000 model. The laser is used at a power of 100%, a focal length of 4.3 mm, a speed of 1000 mm/s and a frequency of 70000 Hz.

[0059] The substrate, the crosslinked solid resin pattern and the non-crosslinked liquid resin are placed for one minute in a bath of good solvent for the non-crosslinked resin. It is, in mass percentages: [0060] more than 99.5% of 1-methoxy-2-propanol acetate (CAS No. 108-65-6) and [0061] less than 0.5% of 2-methoxy-1-propanol acetate (CAS No. 70657-70-4).

[0062] The substrate, the crosslinked solid resin pattern and the non-crosslinked liquid resin are then removed from the bath and good solvent is then delicately sprayed on using a pipette so as to complete the washing (removal) of the non-crosslinked liquid resin. The good solvent is washed from the surface of the substrate and of the crosslinked solid resin pattern with isopropanol using a pipette. Finally, the substrate and the crosslinked solid resin pattern are dried with a stream of nitrogen.

[0063] The lines of the crosslinked solid resin pattern have a width of 30±2 μm and a height of 20±5 μm. The crosslinked resin pattern is a square lattice network with a side length of 3 mm (distance between the centers of two consecutive parallel lines).

[0064] A stack of thin layers is deposited in a compliant manner by cathode-enhanced magnetron sputtering onto the glass+crosslinked solid resin pattern system. This stack of thin layers has the following constitution, in which the thicknesses are in nm: Si.sub.3N.sub.4 20/SnZnO 6/ZnO 7/NiCr 0.5/Ag 9/NiCr 0.5/ZnO 5/Si.sub.3N.sub.4 40/SnZnO 30/ZnO 5/NiCr 0.5/Ag 14/NiCr 0.5/ZnO 5/Si.sub.3N.sub.4 28. The ZnO layers are nonporous. This stack with a thermal control function is temperable.

[0065] The glass substrate, the crosslinked solid resin pattern and the stack of mineral layers are tempered in a thermal annealing furnace sold under the registered brand name Nabertherm® (N41/H model), at 650° C. for 10 minutes, so as to give the substrate and its stack of mineral layers their final mechanical properties. Tempering also makes it possible to partially remove the crosslinked solid resin pattern, thus detaching the mineral layers which cover it. A mechanical action should be applied so as to fully remove the resin residues; to this end, this mechanical action is sufficient in the absence of the heat treatment since the lines of the crosslinked solid resin pattern have a width of less than 40 μm.

[0066] The final product has the stack of thin layers described above structured in a pattern corresponding to the negative of that made with the resin.

[0067] The transmission of electromagnetic waves through this glazing and through a comparative glazing, which differs from the glazing of the invention only in the presence of the stack of magnetron mineral layers over its entire surface, is measured.

[0068] For frequencies of 0.9, or 2.4, or 5 GHz, respectively, the transmission attenuation of the glazing of the invention, including the magnetron stack except in a grating pattern of 3 mm×3 mm, with a line width of 30 μm, is −9, or −19, or −25 dB, respectively. For the comparative glazing without the grating pattern free of the magnetron stack, it is −25, or −40, or −54 dB, respectively.

[0069] Thus, the invention provides a functional glazing with decreased transmission attenuation of waves with frequencies of between 0.4 and 5 GHz.