Method of adjusting the parallelism of a fiber block with a chip surface

1. A method of adjusting the parallelism of a surface of a block of optical fibers with a surface of a semiconductor chip or wafer laid on an XY table, comprising the steps of:

a) providing a sensor rigidly attached to the XY table and a handling arm supporting the block, said surface facing the XY table;

b) for each of a set of points of the surface of the block, at least three of which are non-aligned, displacing with respect to each other the XY table and the block in directions X and/or Y to place the sensor opposite the point, and estimate, with the sensor, the distance along the Z direction between the point and the sensor; and

c) modifying, by taking into account the distances along the Z direction, the orientation of the block by means of the handling arm to provide the desired parallelism.

2. The method of claim 1 , wherein the sensor is a contact sensor, step b) comprising, for each point, displacing the block along the Z direction from a reference position to a position where it is placed into contact with the sensor, and determining the distance along the Z direction traveled by the block between the reference and contacting positions.

3. The method of claim 2 , wherein the displacement along the Z direction of the block is ensured by a stepping motor, associated with means for measuring the number of steps.

4. The method of claim 2 , wherein the sensor comprises an element deformable along the Z direction, a device for measuring the deformation along the Z direction, and a contacting element assembled on the deformable element, step b) comprising, for each point, displacing the block along the Z direction until the element deformable along the Z direction is deformed, and determining the distance along the Z direction traveled by the block between the reference position and a position where the point is placed into contact with the contacting element.

5. The method of claim 4 , wherein the contacting element is a ball, the element deformable along the Z direction is a flexible blade, and the deformation measurement device is a strain gauge arranged on the blade.

6. The method of claim 1 , wherein, at step b), the displacement of the XY table and of the block with respect to each other is performed by displacing the XY table.

7. The method of claim 1 , wherein each point is arranged in the vicinity of a corner of said surface.

8. The method of claim 1 , wherein after each estimation of two distances along the Z direction performed at step b), step c) is partly carried out by modifying the orientation of the block based on the displacement in the X and/or Y direction performed between these two points and on the corresponding difference between distances along the Z direction.

9. A test station comprising a handling arm and an XY table, capable of implementing the method of claim 1 .

10. The test station of claim 9 , further comprising a control and processing circuit capable of receiving the output signal of the sensor, of storing the distances along the Z direction, and of supplying control signals to the XY table and to the handling arm to automatically implement the method.