DE3922233A1 - Precipitating. metal layers from metal organic cpds. - by irradiating with light energy photon beam - Google Patents

Abstract

Metal layers are pptd. from metal organic cpd. such as metal carboxylate, metal acid ester, metal alcoholate, metal chelate, metal alkyl polymer and other metal complexes contg. a metal-C or metal-O bond, by irradiating with a photon beam. The substrates coated may be ceramic, glass, metal, plastic. The photon beam is provided by a high energy beam, pref. a laser beam. The process is carried out in a vacuum, normal atmos. N2, O2, or inert gas atmos. USE/ADVANTAGE - Esp. producing conduction paths in a coating during the mfr. of conductor plates Wide range of cpds. can be used in a process which is safer and more easily controlled than the prior art plasma gas method.

Description

H. Suhr describes in "Plasma Synthesis and Coatings organic and organometallic compounds ", metal surface 42 (1988), 10, 467-472, the use of plasmas according to the PECVD process.

The photolytic CVD process also describes metal deposition using organometallic compounds.

The metal compounds used in the above processes are divided into metal alkyls [e.g. B. Cd (CH₃) ₂; Gd (CH₃) ₃; Pb (CH₃) ₄], metal carbonyls [e.g. B. Cr (CO) ₆; Fe (CO) ₅], Metal chelates and metal ¶ complexes.

According to the above procedures, plasmas are used organically unsaturated compounds and those in the gas phase volatile organometallic compounds initially plasma polymers formed, depending on the starting product and atmospheric Conditions in the further course of the reaction metallic deposits deliver.

Requirement for use according to the known methods is, however, sufficient volatility and thermal stability the organometallic compound. Another disadvantage with The use of such connections is extremely critical handling. Because of its flammability and high toxicity extreme safety conditions must be taken into account. Next are the achievable deposition rates of the metal layer only difficult to control and according to the test conditions very specific.  

For us, the task was to develop a universal one Process, which no longer has the disadvantages mentioned owns. In contrast to the previously known methods allowed the method described below uses volatile and non-volatile organometallic compounds. The procedure also enables the use of inexpensive technical metal connections, the in a plasma and laser independent, external Work process are generated. In principle, everyone can organometallic compounds are used which have a Me-C or Me-O bond, especially the following:

Metal carboxylates:
e.g. B. Cu-abietate, Zn-benzoate, Cu-naphthenate, V-hexanate, bi-octoate, Pb-nonate, Ce-decanate, Cr-oleate, Fe-tallate, Co-oxalate, Mn-linoleate, Zn-acrylate, Ni stearate
Metallic acid ester:
e.g. B. propyl titanate, butylpolytitanate, tianacetate, ethyl glycol titanate, zirconium butylate, triethanolamine zirconate
Metal alcoholates:
e.g. B. Mg propylate, Al-butoxide, Ba-phenolate
Metal chelates:
e.g. B. Pd acetylacetonate, Au acetylacetonate
Metal alkyls / aryls (polymer):
e.g. B. methylpolysiloxane, phenylpolysiloxane
Metal ¶ complexes:
e.g. B. ferrocene, ethyl ferrocene, chromocene, 2,2-bis (ethylferrocenyl) propane

The organic metal compounds that can be split by photon radiation can be used as a uniformly defined connection also combined with organic compatible polymer binders, as they are known from the paint industry. The result is the use of several compound and metal mixtures After laser treatment, metal alloys of all kinds Composition.

The organometallic layers can be depending on the resulting Molar mass cross-linked in solvent or multidimensional Body of great chemical / mechanical resistance be.

As a substrate on which the metal from the organometallic Connection should be separated, all are suitable cannot be changed by the correspondingly applied laser radiation Materials such as B. metal, ceramic, glass, plastic etc.

The organometallic compounds can be mixed with all the usual applied application methods that allow defined layer thicknesses be such. B. all atomization, casting, dipping, rolling and printing process. The advantage of the respective application process is the application over wide layer thickness ranges, whereby can be worked between µ and mm.

The manufactured organometallic layers dry physically or chemically cross-linking. Radiation-curing heat processes accelerate curing.  

Prerequisite for the possibility of metal formation through Photon radiation is that the laser light interacts with the organometallic coating occurs. For optimal adjustment to achieve lasers of different wavelengths used.

Depending on the "laser conditions" and the chosen working atmosphere occurs when the organometallic films split in addition to a series of decomposition and combustion products also elemental carbon that is growing in the Can store metal layer.

Another property is that in an oxygen-containing atmosphere the oxidation of base metals progresses to the oxide or Inclusions are present.

Pure metals are most likely to result from precious metal compounds. This applies in particular to the simultaneous use of Noble gas atmosphere too.

Choosing the right atmospheric conditions therefore of crucial importance.

The metals generated by laser radiation can be used with appropriate inorganic / organic materials for insulation be treated.  

Experimental examples 1-4

Trial 1
contains the combination of metal carboxylate (Fe-ocloate) / metal acid ester (Ti-butylate) / metal alcoholate (Al-butylate)
Trial 2
includes the combination of metal carboxylate (Cu octoate) / metal acid ester (Ti butoxide) / metal alcoholate (Al butoxide)
Trial 3
contains the combination of metal carboxylate (Cu-decanate) / metal alcoholate (Al-butylate)
Trial 4
contains the combination of metal carboxylate (Cu-naphthenol) / metal acid ester (Zr-butylate)
Trial 5
contains the combination of metal carboxylate (Cu-octoate) / metal acid ester (Ti-butylate) / metal-¶ complex (ethyl ferrocene)

Recipes

According to the above manufacturing regulations prepared the organometallic compounds. Result stable liquid media. These are in a defined layer thickness (e.g. 100 µ wet film) applied to glass plates. After drying They are heat forced at 95 ° C overnight or for 15 minutes Target materials with the Nd-YAG laser, from Optronic, type 815, laser irradiated. The focus was on laser treatment. Depending on the laser processing parameters created, it works as follows put together,

• - processing speed, laser current, pulse frequency and pulse length,

different track depths and widths can be achieved. The laser treatment in cw mode, i.e. H. under continuous exposure to radiation, perform and targeted metal deposition produce.

The laser exposure results in electrical conductor tracks. The electrical resistance when applying a DC voltage of 1.5 volts is on the order of a few hundred ohms.

Claims (8)

1. A process for the deposition of metals from organometallic compounds with the aid of photon radiation, characterized in that the metal compound is a metal carboxylate, metal acid ester, metal alcoholate, metal chelate, metal alkyl (polymer), metal-¶ complex. 2. The method according to claim 1, characterized in that the above organometallic compounds can be combined. 3. The method according to claim 1-2, characterized in that the organometallic compounds with the usual application methods be applied outside the process. 4. The method according to claim 1-3, characterized in that as Ceramic, glass, metal, plastic substrates are used will. 5. The method according to claim 1-4, characterized in that High energy density photon radiation is applied. 6. The method according to claim 1-5, characterized in that laser light is used as photon radiation. 7. The method according to claim 1-6, characterized in that Vacuum / normal atmosphere, nitrogen / oxygen / rare gas atmosphere is applied. 8. The method according to claim 1-7, characterized in that through the photon radiation, electrically conductive layers result, which are used for conductor tracks / plates can.