Process for manufacturing assembly pads on a carrier for the self-assembly of an electronic circuit on the carrier

1. A method of self-assembly of an element onto a surface of a support comprising the steps of:

providing a support comprising:

at least one assembly pad on said surface; and

nanometer- or micrometer-range pillars on said surface around the at least one assembly pad, each nanometer- or micrometer-range pillar comprising at least one cylindrical or truncated cone amorphous silicon or polysilicon core;

depositing a drop of a liquid on the at least one assembly pad, the liquid drop having a static angle of contact on the at least one assembly pad smaller than or equal to 15°, the liquid drop having a static angle of contact on the nanometer- or micrometer-range pillars greater than or equal to 150°; and

bringing the element into contact with the drop, which results in a self-assembly of the element with respect to the support.

2. The method of claim 1 , wherein the nanometer- or micrometer-range pillars have a height H and a width a measured in a plane parallel to the surface, wherein adjacent nanometer- or micrometer-range pillars are spaced apart by an interval b measured in a plane parallel to the surface and wherein height H, width a, and interval b verify the following relations:

a

<

b

4

H

>

b

b

<

Γ

ρ

⁢

⁢

g

where Γ is equal to the surface tension of the liquid, p is equal to the density of the liquid, and g is the gravitational constant.

3. The method of claim 1 , wherein each nanometer- or micrometer-range pillar comprises at least at its surface a fluorinated material.

4. The method of claim 3 , wherein the fluorinated material is a fluorocarbon material.

5. The method of claim 1 , further comprising a protrusion comprising sides and a top, the at least one assembly pad being on the top.

6. The method of claim 5 , wherein each nanometer- or micrometer-range pillar comprises at least at its surface a fluorinated material and wherein the sides comprise at their surface the fluorinated material.

7. The method of claim 1 , wherein the step of providing the support comprises the forming, on the support, of the nanometer- or micrometer-range pillars around a location of the at least one assembly pad, a liquid drop having a static angle of contact on the at least one assembly pad smaller than or equal to 15°, the liquid drop having a static angle of contact on the nanometer- or micrometer-range pillars greater than or equal to 150°.

8. The method of claim 7 , comprising depositing an amorphous silicon or polysilicon layer on the surface and etching the amorphous silicon or polysilicon layer to form the nanometer- or micrometer-range pillars.

9. The method of claim 8 , comprising depositing a porous layer on the amorphous silicon or polysilicon layer.

10. The method of claim 7 , wherein the step of forming the nanometer- or micrometer-range pillars comprises forming at the surface of each nanometer- or micrometer-range pillar a layer of at least one fluorinated material.

11. The method of claim 7 , comprising exposing the nanometer- or micrometer-range pillars and the location to an ultraviolet treatment in the presence of ozone to form the at least one assembly pad at said location.

12. The method of claim 1 , wherein the element is an electronic circuit chip.

13. The method of claim 1 , further comprising the steps of:

drying the drop; and

bonding the element to the support.