METHOD FOR JETTING DROPLETS OF AN ELECTRICALLY CONDUCTIVE FLUID

• US 20160107441A1
• Filed: 12/22/2015
• Published: 04/21/2016
• Est. Priority Date: 07/11/2013
• Status: Active Grant

• Current Assignee: Océ-Technologies B.V. (Canon Inc.)
• Original Assignee: Océ-Technologies B.V. (Canon Inc.)
• Inventors: JOPPEN, Sandor H.G., WIJSHOFF, Hermanus M.A.
• Granted Patent: US 9,744,763 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B22F 2005/004 Article comprising helical form elements B22F5/085 takes precedence
• CPC Class Codes: B22F 2009/084 combination of methods
• CPC Class Codes: B22F 2009/0892 casting nozzle; controlling metal stream in or after the casting nozzle
• CPC Class Codes: B22F 2202/05 Use of magnetic field
• CPC Class Codes: B22F 2202/06 Use of electric fields
• CPC Class Codes: B22F 2999/00 Aspects linked to processes or compositions used in powder metallurgy
• CPC Class Codes: B22F 9/08 by casting, e.g. through sieves or in water, by atomising or spraying using electric discharge B22F9/14
• CPC Class Codes: B41J 2/06 by electric or magnetic field
• CPC Class Codes: B41J 2/14 Structure thereof only for on-demand ink jet heads
• CPC Class Codes: B41J 2202/04 Heads using conductive ink
• CPC Class Codes: H05K 2203/104 Using magnetic force, e.g. to align particles or for a temporary connection during processing
• CPC Class Codes: H05K 2203/105 Using an electrical field; Special methods of applying an electric potential electroplating H05K2203/0723
• CPC Class Codes: H05K 2203/128 Molten metals, e.g. casting thereof, or melting by heating and excluding molten solder spraying droplets of molten metal H05K2203/1344
• CPC Class Codes: H05K 3/10 in which conductive material is applied to the insulating support in such a manner as to form the desired conductive pattern

Abstract

In a method for jetting a droplet of an electrically conductive fluid, a Lorentz force is generated in the electrically conductive fluid. The Lorentz force is directed into an actuation direction. The actuation direction is a direction opposite to the droplet ejection direction. A jetting device is provided for printing a droplet of an electrically conductive fluid.

Claims

1. Method A method for jetting a droplet of an electrically conductive fluid using a jetting device, the jetting device comprising a fluid chamber body defining a fluid chamber and having an orifice operatively coupled to the fluid chamber for ejecting a droplet in a droplet ejection direction, and an actuator, the actuator comprising:

a magnetic field generator configured to generate a magnetic field in at least a part of the fluid chamber; and

an electrical current generator configured to generate an electrical current in the electrically conductive fluid in the part of the fluid chamber provided with the magnetic field,

the method comprising the step of;

a) applying an electrical current to the electrically conductive fluid positioned in the magnetic field, thereby generating a Lorentz force in the electrically conductive fluid, the Lorentz force being directed in an actuation direction, the actuation direction being in an opposite direction compared to the droplet ejection direction,

wherein, as a result of the Lorentz force generated in step a), ejecting a droplet of the electrically conductive fluid in the droplet ejection direction.

2. The method according to claim 1, wherein at least an inner surface of the fluid chamber body is provided with a wetting coating.

3. The method according to claim 2, wherein the wetting coating comprises at least one of the group consisting of mono-tungsten-carbide (WC), di-tungsten-carbide W₂C), tri-tungsten-carbide (W₃C) and boron-nitride (BN).

4. The method according to claim 1, wherein the electrically conductive fluid is a molten metal.

5. The method according to claim 4, wherein the molten metal is selected from the group consisting of molten silver, molten copper and molten gold.

6. The method according to claim 1 for jetting a series of droplets of the electrically conductive fluid, the series of droplets comprising at least one small droplet and at least one large droplet, wherein the at least one small droplet is jetted in step a), and wherein,

in step a), the actuation direction is a first actuation direction and the droplet ejected is a small;

droplet,

and wherein the method further comprises the step of;

b) applying an electrical current to the electrically conductive fluid positioned in the magnetic field, thereby generating a Lorentz force in the electrically conductive fluid, the Lorentz force being directed in a second actuation direction, the second actuation direction being in a direction parallel to the droplet ejection direction,

as a result of the Lorentz force generated in step b), ejecting a large droplet of the electrically conductive fluid in a the droplet ejection direction.

7. A jetting device for printing a droplet of an electrically conductive fluid, the jetting device comprising:

a fluid chamber body defining a fluid chamber for holding an amount of the electrically conductive fluid;

an actuation assembly configured to expel droplets of the electrically conductive fluid from the chamber through an orifice in the droplet ejection direction, the actuation assembly comprising

a magnetic field generator configured to generate a magnetic field in at least a part of the fluid chamber; and

an electrical current generator configured to generate an electrical current in the electrically conductive fluid in the part of the fluid chamber provided with the magnetic field; and

a controller configured to in operation control at least one of the electrical current and the magnetic field such that in operation at least one small droplet and/or at least one large droplet is jetted.