Process for producing a structured metal layer on a substrate body, and substrate body having a structured metal layer

Abstract

Process for producing a structured metal layer on a substrate body, in which either a structured bonding layer is applied to the substrate body, in order for a metal foil or a metal powder to be fixed on this bonding layer, or in which a metal foil or a metal layer is applied to the entire surface of a substrate body made from a plastics material and is pressed onto the substrate body with the aid of a structured, heated ram and fixed by a subsequent setting of the substrate body. The metal layer is structured by mechanical removal of those regions of the metal foil or of the metal powder which are not joined to the adhesive or to the substrate body.

Description

CROSS-REFERENCE TO RELATED APPLICATION [0001] This application is a continuation of International Patent Application Serial No. PCT / DE02 / 03305, filed Sep. 5, 2002, which published in German on Apr. 3, 2003 as WO 03 / 028416, and is incorporated herein by reference in its entirety.FIELD OF THE INVENTION [0002] The invention relates to a process for producing a structured metal layer on a substrate body, and to a substrate body produced using this process. BACKGROUND OF THE INVENTION [0003] Structured metal layers are required, for example, in printed-circuit boards, in chip cards operated without contact, in RFID tags or in other substrates in which various electrical components are to be electrically connected to one another. There are various processes which can be used to produce structured metal layers at greater or lesser cost and in a shorter or longer time. In particular, it is a regular objective for the structured metal layers to have low electrical resistances and, in the cas...

AI Technical Summary

Benefits of technology

[0012] The invention is based on an object of providing a different process for producing a metal layer on a substrate body, in which the production of a structured metal layer of any desired thickness can be achieved in a simple and time-saving manner.

[0013] Furthermore, it is also intended to provide a substrate body having a structured metal layer which can be produced at low cost and is highly reliable.

[0018] The process described can be used for substrate bodies made from any desired material, for example plastics, metal, glass and so on. The bonding layer is preferably designed as a layer of adhesive with good adhesion properties. The bonding layer can be applied to the substrate body for example using a screen-printing process, which is known per se, or using a ram-printing process. Of course, it would also be possible for the bonding layer initially to be applied to the entire surface and then to be structured photolithographically. However, applying the bonding layer by means of a printing process has the advantage of lower costs compared to a photolithographic process, on account of high working speeds and the fact that only small amounts of chemicals are used. The bonding layer used may in principle be any desired material, provided that its adhesive properties are such that, during the mechanical removal of the metal foil, the regions which are joined to the bonding layer are not also removed. The adhesive properties of the bonding layer are essentially responsible for the conductor structures which are to be produced having sharp contours.

[0028] Despite this low thickness, the metal foils are easy to handle with success, so that the processes according to the invention can be carried out without problems using simple means. In addition to the low costs resulting from the high working speeds and the possibility of using existing installations, the processes according to the invention are distinguished by the fact that there is intimate bonding between the metal foil and the bonding layer or between the metal foil and the substrate body. As a result, it is possible to produce components with a high level of reliability. The fact that there is little use of chemicals means that the processes are also environmentally friendly.

Problems solved by technology

Apart from high production costs, this procedure has the drawback that the bonding between metal foil and substrate body is insufficient, and the structured metal foil can become detached.

These pastes have the drawback of often having high electrical resistances and of being expensive if the conductive paste contains conductive silver particles.

However, this procedure is unsuitable for production in large numbers, since a multiplicity of production tools are required, there is a high wastage of material, the metal foil has to have at least a predetermined minimum thickness and the time required to produce one unit is very long.

However, complete removal of the metal powder which is not joined to the substrate sheet purely under the force of gravity must be unlikely, and consequently the conductor structure will not be clearly defined or subsequent removal steps are required.

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