DE102008025108A1 - Process for the production of nanoscale electrically conductive multilayer systems - Google Patents

Abstract

The invention relates to a method for producing nanoscale electrically conductive multilayer systems on surfaces, wherein the coated surfaces are used in particular for heat or sun protection or in heating elements. The invention has for its object to provide a way that overcomes the disadvantages of the established methods for the deposition of electrically conductive layers. According to the invention, this object is achieved in a method for coating substrates with an electrically conductive layer system in that at least one electrically conductive layer is applied by a flame pyrolysis method.

Description

The The invention relates to a method for the production of nanoscale electrically conductive multilayer systems on surfaces, the coated surfaces being used in particular for heat or sunscreen or in heating elements are used.

PVD (Physical vapor deposition) have long been state of the art. By bombarding atoms of a material with high energy Inert gas ions (sputtering process) make it possible for these tear out the composite and deposit it on the substrate.

For deposition of metal layers predominantly these PVD methods (eg. DE 10 2004 001 655 A1 ) used. However, these require a very complex and at the same time very expensive equipment construction, since very low pressures and / or special atmospheres are needed.

Methods are also known in which organometallic and / or organometallic compounds (precursors) are introduced into a flame and decomposed by combustion processes and deposited on a surface. These processes are referred to as combustion CVD processes or flame pyrolysis processes. In the patent application DE 10 2006 029 617 A1 hot glass surfaces are coated by this method.

The thermal CVD requires high substrate temperatures and is therefore only suitable for a few materials. (Lit .: HJ glasses, thin-film technology on flat glass, Schorndorf, Verlag Karl Hofman, 1999 )

Also are from the patent application DE 43 20 931 A1 Coatings with electrically conductive layers known. Here, the multilayer systems of adhesion-promoting layers, barrier layers and protective layers are constructed, between which the electrically conductive layer is arranged.

Of the Invention is based on the object, a possibility indicate the disadvantages of the established methods for the deposition of electrically conductive layers overcomes.

According to the invention this task in a process for coating substrates solved with an electrically conductive layer system thereby that at least one electrically conductive layer by a flame pyrolysis method is applied. The main advantage of the invention is in the relatively simple and especially inexpensive construction of the coating apparatus. The used Combustion-CVD method is under atmospheric pressure and operated without shielding gases. Another advantage of the invention is in the use of a relatively cold substrate (maximum 80 ° C Preheating temperature) which also thermally not highly resilient Materials, such as plastics, can be coated. In addition, the use and the combination of special precursors needed to get the desired property of the multilayer system to obtain.

According to the invention sets The multi-layer system of individual layers together, which fulfill different purposes. These include Barrier effect and protection. Between these individual layers is at least one electrically conductive layer, which elemental or oxidic can be incorporated. The multi-layer system can also be composed of several such basic modules. The total layer thickness of the multilayer system should be less than 200 nm, the layer thicknesses the individual layers are 10 to 50 nm.

The electrically conductive layers are made of silver or gold, which from a layer thickness of a few nanometers (<10 nm) a good electrical conductivity own and thus for applications where a high IR reflection is important to consider. silver layers also offer up to a certain layer thickness (up to about 20 nm) a high transmission in the UV and visible range.

According to the invention such deposition also with an atmospheric pressure plasma conceivable. The film formation processes in the conversion of the corresponding Precursors are very similar to those in the flame, so that also used to deposit electrically conductive nanoscale multilayer systems can be.

The Invention will be described below with reference to embodiments be explained in more detail. In the corresponding Drawing shows

1 the construction of a multi-layer system.

The inventive method is directed to the production of a multi-layer system 1 based on tungsten oxide 3 , Zirconium oxide 4 , electrically conductive layer (silver, gold, ...) 5 and a protective layer 6 on a substrate 2 , substrates 2 can be glass, plastic or even metals.

example 1

The deposition of a multilayer system 1 on glass can be used as heat protection glazing application. The electrically conductive layer, which primarily but not necessarily consists of silver, thereby carries the property of the reflection of the IR radiation. Silver still has a high transmission in the UV and visible range with good IR reflection.

Contents of the solution according to the invention is the coupling of an oxide multilayer system with a silver layer 5 , This silver layer 5 is here directly on the oxide multilayer system consisting of tungsten oxide 3 and zirconia 4 or applied to a multi-layer system consisting of several additional layers. At least the silver layer 5 is deposited by flame pyrolysis. As precursor substances, organometallic and / or organometallic compounds containing the corresponding element are used for the flame pyrolytic deposition of the metal and metal oxide layers. However, it is important to tailor the individual precursors in order to obtain the desired multilayer system with the desired properties.

The parameter range for the flame pyrolytic deposition of the individual layers is given below: Flame pyrolysis system with temperature-controlled travel table and burner Gas mixture: Fuel gas mixture (propane / air) Volume flow of gas: 1-2 l / min Volume flow air: 20-50 l / min Burner: Hole burner with homogenizer attachment (width 220 mm) Preheating temperature traversing table: 30-80 ° C Speed traversing: 15-100 mm / s Distance substrate burner: 4-8 mm Parameter range for tungsten oxide film deposition precursor: Ammonium (meta) tungstate in methanol / water (2: 1) precursor concentration: 0.01-0.5 mol / l Number of passes: 5-20 Layer thickness: up to 30 nm Parameter range for zirconium oxide layer deposition precursor: Zircon (IV) acetylacetonate in ethanol / water precursor concentration: 0.05-0.5 mol / l Number of passes: 5-20 Layer thickness: up to 20 nm Parameter range for silver layer deposition precursor: Silver (I) carboxylate in ethanol / water (2: 1) precursor concentration: 0.1-0.2 mol / l Number of passes: 10-100 Layer thickness: up to 70 nm

Example 2

Also The use of gold as an electrically conductive layer is conceivable. On a large scale, the gold separation is rather unrealistic, because the enormously high raw material prices prevent mass production. However, for low quantities and / or not flat substrates where high IR reflection is required can, with the flame pyrolysis this multilayer system very much be applied inexpensively.

Content of the solution according to the invention is the coupling of an oxide multilayer system with a gold layer. This gold layer is here directly on the oxide multilayer system consisting of tungsten oxide 3 and zirconia 4 or applied to a multi-layer system consisting of several additional layers. At least the gold layer 5 is deposited by flame pyrolysis. As precursor substances, organometallic and / or organometallic compounds containing the corresponding element are used for the flame pyrolytic deposition of the metal and metal oxide layers. However, it is important to match the individual precursors to one another in order to obtain the desired multilayer system

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• DE 102004001655 A1 [0003]
• DE 102006029617 A1 [0004]
• - DE 4320931 A1 [0006]

Cited non-patent literature

• - HJ glasses, thin-film technology on flat glass, Schorndorf, Verlag Karl Hofman, 1999 [0005]

Claims (9)

A process for the production of nano-scale electrically conductive multi-layer systems, which consists of a substrate and the overlying layers for adhesion, barrier effect and protection, characterized in that at least one electrically conductive layer is deposited by means of a flame pyrolysis process at atmospheric pressure. Method according to claim 1, characterized in that that the electrically conductive layer as a metallic layer is deposited. Method according to claim 1, characterized by first apply a layer to the adhesion promoter substrate Tungsten oxide is applied. Method according to claim 1, characterized by that as a second layer for barrier action, a layer of zirconium oxide is applied. Method according to claim 1, characterized in that that on the substrate first, a layer consisting of molybdenum oxide is applied. Method according to claim 1, characterized in that that on the substrate, first, a layer consisting of chromium oxide is applied. Method according to claim 1, 2 5 or 6, characterized that on the first layer, a second layer consisting of tin oxide is applied. Method according to claim 1, 2 5 or 6, characterized that on the first layer, a second layer consisting of titanium oxide is applied. Method according to one of the preceding claims, characterized in that as the final layer a protective layer consisting of Al oxide, Si oxide, Sn oxide or Zn oxide is applied.