Method and arrangement for transferring electrically conductive material in fluid form on a substrate to be printed
A method and an arrangement are disclosed for transferring electrically conductive material in fluid form onto a substrate. Said substrate is preheated to a first temperature, and of said electrically conductive material there is produced fluid electrically conductive material. The fluid electrically conductive material is sprayed onto the preheated substrate to form a pattern of predetermined kind. The substrate onto which said fluid electrically conductive material was sprayed is cooled to a third temperature, which is lower than the melting point of said electrically conductive material.
1. A method for transferring electrically conductive material in fluid form onto a substrate, said method comprising:
providing a substrate, wherein at least a surface of said substrate is electrically isolating,
preheating said substrate to a first temperature,
heating said electrically conductive material to a second temperature, which is higher than a melting point of said electrically conductive material, thus producing fluid electrically conductive material,
spraying said fluid electrically conductive material onto the preheated substrate to form a pattern of predetermined kind, and
cooling the substrate onto which said fluid electrically conductive material was sprayed to a third temperature, which is lower than or equal to said melting point of said electrically conductive material;
wherein said cooling comprises pressing that surface of the substrate, onto which said fluid electrically conductive material was sprayed, against a roller, and actively keeping a surface temperature of said roller lower than said melting point of said electrically conductive material, wherein pressing against said roller implements said cooling of the substrate.
2. A method according to claim 1 , wherein said preheating of the substrate comprises at least one of the following: pressing against a heating roller, subjecting to heating radiation, subjecting to a heating gas flow.
3. A method according to claim 1 , which comprises unwinding said substrate from a roll prior to said preheating.
4. A method according to claim 1 , which comprises winding the substrate, onto which said fluid electrically conductive material was sprayed, to a roll after said cooling.
5. A method according to claim 1 , wherein said substrate is one of the following: paper, paperboard, cardboard, tissue paper, polymer film, nonwoven fabric, woven fabric, or felt.
6. A method according to claim 1 ,
wherein the step of producing fluid electrically conductive material comprises heating electrically conductive material to a second temperature, which is higher than a melting point of said electrically conductive material, and
wherein the step of spraying said fluid electrically conductive material onto the preheated substrate comprises spraying said fluid electrically conductive material in liquid form onto an area of predefined form by using a controllable nozzle, which responds to a control signal coupled to said controllable nozzle by ejecting some of said fluid electrically conductive material towards the substrate.
7. A method according to claim 1 , wherein the step of spraying said fluid electrically conductive material onto the preheated substrate comprises spraying said fluid electrically conductive material in the form of vapour or colloidal suspension onto an area of predefined form.
8. A method according to claim 7 , which comprises using a controllable combination of a spraying nozzle and a suction nozzle, adapted to remove vapour or colloidal suspension sprayed by said spraying nozzle from the vicinity of said substrate before said vapour or colloidal suspension adheres to said substrate.
9. A method according to claim 1 , comprising spraying said fluid electrically conductive material onto the preheated substrate, then reheating the pattern formed by said electrically conductive material on the surface of the substrate, and subsequently cooling the substrate.
10. A method according to claim 1 , which comprises producing printed electronics on an electrically isolating substrate.
11. A method according to claim 1 , which comprises preconditioning said substrate with an agent that promotes the spreading of fluid electrically conductive material on said substrate.