MATERIAL DEPOSITION IN A MAGNETIC FIELD

Abstract

The present invention provides for depositing a desired pattern (31) of magnetic material (30) on a non-magnetic substrate (20). Control of the deposition pattern (31) is achieved by use of a magnetised template (10) shaped to correspond to the desired deposition pattern. In use, the template (10) is placed behind the substrate (20). Subsequently, the front surface of the substrate (20) is exposed to a solution containing the magnetic material (30) to be deposited. The magnetic material (30) is attracted to the magnetised template (10) and consequently is deposited in a pattern (31) covering areas corresponding to the shape of the template (10).

Claims

1. A method of selectively depositing a desired pattern of a material on a front surface of a non-conductive substrate, the method comprising the steps of: providing a magnetised template corresponding to the pattern to be deposited; positioning the template behind the substrate; and exposing at least the front surface of the substrate to one or more solutions containing magnetic catalytic material to be deposited and selectively depositing a desired secondary material on the deposited catalyst pattern.

2-5. (canceled)

6. A method as claimed in claim 1 wherein the catalytic material comprise ions, colloid or nanoparticles of a catalytic material that exhibits magnetic properties.

7. A method as claimed in claim 6 wherein the nanoparticles comprise both catalytic material and magnetic material.

8. A method as claimed in claim 7 wherein the nanoparticles comprise a core of magnetic material provided with an outer layer, shell or coating of catalytic material.

9. A method as claimed in claim 7 wherein the nanoparticles comprise Janus particles having one end formed of magnetic material and a second end formed of catalytic material.

10. A method as claimed in claim 1 wherein the catalytic material comprises a material for catalysing an electroless plating process.

11. A method as claimed in claim 1 wherein the catalytic material is Carbon, Palladium, Gold, Silver, Copper, Nickel, Tin, Iron, Cobalt, Zinc or Platinum or alloys comprising said substances.

12. A method as claimed in claim 1 wherein the non-conducting substrate is a dielectric.

13. A method as claimed in claim 12 wherein the substrate is formed from a polymer, plastic, ceramic, silicon, glass, fabric or textile.

14. A method as claimed in claim 1 wherein the front surface of the substrate is polished or smoothed before exposure to the solution.

15. (canceled)

16. A method as claimed in claim 15 wherein the secondary material is deposited by use of electroless plating techniques.

17. A method as claimed in claim 15 wherein the secondary material is: Copper, Nickel or Cobalt or alloys or composites comprising Copper, Nickel or Cobalt or wherein the secondary material is: Palladium, Silver, Tin, Zinc or Platinum or Gold or alloys or composites containing such materials.

18. A method as claimed in claim 1 wherein the magnetised template is formed from a ferromagnetic substance.

19. A method as claimed in claim 1 wherein the method is applied to the manufacture of electronic devices.

20. An electronic device comprising one or more electrical components mounted on a non-magnetic substrate, the electrical components connected together via a conducting pattern of magnetic material wherein the electrical device is manufactured using the method of claim 1.

21. (canceled)

Description

DETAILED DESCRIPTION OF THE INVENTION

[0024] In order that the invention may be more clearly understood an embodiment thereof will now be described, by way of example only, with reference to the accompanying drawings, of which:

[0025] FIG. 1 is a schematic illustration of an exemplary magnetised template according to the present invention;

[0026] FIG. 2 is a schematic cross-sectional illustration of the deposition of a magnetic catalytic material on to a substrate using the magnetised template of FIG. 1 according to the method of the present invention;

[0027] FIG. 3 is a schematic illustration of the resultant pattern of material deposited on the substrate of FIG. 2 according to the method of the present invention;

[0028] FIG. 4a is a schematic illustration of a type of compound particle that may be used to implement the method of the present invention;

[0029] FIG. 4b is a schematic illustration of another type of compound particle that may be used to implement the method of the present invention;

[0030] FIG. 5 is a schematic cross-sectional illustration of the deposition of a magnetic material and a catalytic material on to a substrate using the magnetised template of FIG. 1 according to the method of the present invention; and

[0031] FIG. 6 is a schematic illustration of the resultant pattern of material deposited on the substrate of FIG. 5 according to the method of the present invention.

[0032] The present invention provides for depositing a desired pattern 31 of catalytic material 30 on a non-conductive substrate 20. Typically, the substrate 20 is formed from a polymer, plastic, ceramic, silicon, glass or the like.

[0033] Control of the deposition pattern 31 is achieved by use of a magnetised template 10. Turning now to FIG. 1, an example of a magnetised template 10 is provided. The template 10 is formed from a ferromagnetic material, such as iron, and is shaped to correspond to the desired deposition pattern.

[0034] In use, the template 10 is placed behind the substrate 20, as shown in FIG. 2. In some embodiments, a further magnet (not shown) may be placed behind the template 10 to ensure it is magnetised. Subsequently, the front surface of the substrate 20 is exposed to a solution containing the magnetic catalytic material 30 to be deposited. The catalytic material 30 (if paramagnetic) is attracted to the magnetic template 10 and consequently is deposited in a pattern 31 covering areas matching the shape of the template 10 as is shown in FIG. 3. The skilled man will appreciate that if the catalytic material 30 is diamagnetic, it is repelled from the magnetic template 10 and consequently is deposited in a pattern 31 covering areas except those matching the shape of the template 10.

[0035] In order to encourage the movement of the magnetic material 30 under the magnetic field across the front surface of the substrate 20 to the desired areas, the front surface of the substrate may be polished or smoothed before exposure to the solution.

[0036] Where the catalytic material 30 is not inherently magnetic, it may be provided in the form of particles, typically nanoparticles, combining both catalytic material and magnetic material. One example of such a particle 32 is shown in FIG. 4a. In this example, the particle 32 comprises a core 33 of magnetic material (such as Iron Oxide or the like) and an outer layer 33 of catalytic material. Another example of a particle 35 is the Janus particle shown in FIG. 4b. The Janus particle 35 comprises a first face 36 formed from magnetic material (such as Iron Oxide or the like) and a second face 37 formed from catalytic material.

[0037] In alternative embodiments where the catalytic material 30 is not inherently magnetic, magnetic blocker particles 40, typically microparticles, may be added to the solution. As is illustrated in FIG. 5, the magnetic material 40 (if paramagnetic) is attracted to the magnetic template 10 and consequently is deposited in a pattern 41 covering areas matching the shape of the template 10 as is shown in FIG. 6. The catalytic material 30 is consequently deposited in a pattern 31 covering areas except those matching the shape of the template 10. The skilled man will of course appreciate that if the magnetic material 40 were diamagnetic, the magnetic material 40 would instead be repelled by the template 10 and the deposition patterns 41, 31 of magnetic material 40 and catalytic material 30 would be reversed.

[0038] In embodiments using both catalytic material 30 and magnetic material 40, the materials 30, 40 may be applied in a single solution. Alternatively, a solution comprising the magnetic material 40 may be applied before the application of a solution comprising catalytic material 30. In either case, the method may involve removing the magnetic blocker particles 40 after deposition of the catalytic material 30. Typically this can be achieved by a suitable washing process.

[0039] In some instances, the catalytic material 30 is a catalyst for a subsequent process. In particular, the catalytic material 30 may be Palladium, Gold, Silver, Copper, Tin, Carbon, Iron, Cobalt, Zinc, Platinum or any other material which is catalytic for electroless plating. The catalytic material may also comprise a colloids, alloys, nanoparticles or microparticles formed from such materials. Subsequently, the method may include the further step of using an electroless plating method to deposit secondary material such as Copper, Nickel or Cobalt over the catalysed areas. In this manner, the present invention provides a ready process for forming a conductive pattern on a non-conductive substrate which minimises waste material.

[0040] The above embodiment is described by way of example only. Many variations are possible without departing from the scope of the invention as defined in the appended claims.