Apparatus for electroless metallization of a target surface of at least one workpiece, and method and diffuser plate for this purpose
The present invention relates to an apparatus ( 1 ) for the electroless metallization of a target surface of at least one workpiece ( 5 ), having a vessel ( 10 ) to accommodate a metallization solution having an inlet ( 15 ) and an outlet ( 16 ) for the metallization solution, and a holder ( 20 ) for accommodating the at least one workpiece ( 5 ) and can be arranged within the vessel ( 10 ), wherein at least one diffuser plate ( 30 ) is provided between the at least one inlet ( 15 ) and the holder ( 20 ) and has a multitude of diffuser openings ( 35 ) spaced apart in a plane of a plate (E), and wherein a movement device ( 40 ) is provided, which can move the diffuser plate ( 30 ) in at least one spatial direction in the vessel ( 10 ). The present invention further relates to a method for the electroless metallization of the target surface of the at least one workpiece ( 5 ).
1. An apparatus ( 1 ) for the electroless metallization of a target surface of a plurality of workpieces ( 5 ), comprising:
a vessel ( 10 ) for receiving a metallization solution with an inlet ( 15 ) and an outlet ( 16 ) for the metallization solution, and
a holder ( 20 ) for holding the plurality of workpieces ( 5 ), which can be arranged in the vessel ( 10 ),
wherein a diffuser plate ( 30 ) is provided between the at least one inlet ( 15 ) and the holder ( 20 ), which has a plurality of diffuser openings ( 35 ) spaced apart in a plane of a plate (E),
wherein a movement device ( 40 ) is provided, which can move the diffuser plate ( 30 ) in at least one direction in space in the vessel ( 10 ),
wherein a first diffuser opening ( 35 ), from among the plurality of diffuser openings ( 35 ), has:
a first cross-sectional area (A 1 ) on a first side ( 31 ) of the diffuser plate ( 30 ), and
a second cross-sectional area (A 2 ) on a second side ( 32 ) of the diffuser plate ( 30 ), opposite to the first side ( 31 ) thereof,
wherein the first cross-sectional area (A 1 ) is greater than the second cross-sectional area (A 2 ),
wherein the second side ( 32 ) of the diffuser plate ( 30 ) faces the plurality of workpieces ( 5 ),
wherein the first diffuser opening ( 35 ) is conical or cone-shaped,
wherein the diffuser plate ( 30 ) is movable in a direction parallel to a normal vector of the plane of a plate (E), and
wherein the holder ( 20 ) is connected to the movement device ( 40 ).
2. The apparatus ( 1 ) according to claim 1 , characterized in that the movement device ( 40 ) has the diffuser plate ( 30 ) in at least one recurring movement in one of the spatial directions perpendicular to the plane of a plate (E).
3. The apparatus ( 1 ) according to claim 1 , characterized in that the holder ( 20 ) is movable in the vessel ( 10 ).
4. The apparatus ( 1 ) according to claim 1 , characterized in that the holder ( 20 ) is configured to be moved by the movement device ( 40 ) or the holder ( 20 ) is fixedly arranged in the vessel ( 10 ).
5. The apparatus ( 1 ) according to claim 1 , characterized in that a ratio between the first cross-sectional area (A 1 ) and the second cross-sectional area (A 2 ) is at least 1.1, i.e. A 1 /A 2 ≥1.1.
6. The apparatus ( 1 ) according to claim 1 , characterized in that the plurality of diffuser openings ( 35 ) are aligned in the at least one spatial direction.
7. The apparatus according to claim 1 , characterized in that the plurality of diffuser openings ( 35 ) are arranged in rows in the plane of a plate (E) and that adjacent rows are arranged so as to be offset to one another.
8. The apparatus according to claim 1 , characterized in that the holder ( 20 ) can accommodate several workpieces ( 5 ) spaced apart in rows by gaps and/or that the plurality of diffuser openings ( 35 ) are directed into the gaps.
9. The apparatus ( 1 ) according to claim 1 , characterized in that the diffuser plate ( 30 ) corresponds to the shape of the vessel ( 10 ).
10. The apparatus ( 1 ) according to claim 1 , characterized in that the diffuser plate ( 30 ) has a frame ( 34 ), which projects out from the plane of a plate (E) of at least one of the first and second sides ( 31 , 32 ).
11. The apparatus ( 1 ) according to claim 10 , characterized in that the frame ( 34 ) has flow means through which the metallization solution can be guided in the direction of the plurality of diffuser openings ( 35 ).
12. A method for the electroless metallization of a target surface of at least one workpiece ( 5 ), in particular with an apparatus ( 1 ) according to claim 1 , comprising the following method steps:
inserting at least one workpiece ( 5 ) into the holder ( 20 ),
positioning the holder ( 20 ) in the vessel filled with a metallization solution, and
flushing the at least one workpiece ( 5 ) with the metallization solution by moving the diffuser plate ( 30 ) in order to form jets formed by the diffuser openings ( 35 ) in the metallization solution.
13. The method according to claim 12 , characterized in that the diffuser plate ( 30 ) is cyclically moved by the movement device ( 40 ) and that the jets exit alternately from the diffuser openings ( 35 ) and are generated by backflows flowing into the diffuser openings ( 35 ).
14. The method according to claim 12 , characterized in that the holder ( 20 ) with the least one workpiece ( 5 ) in the vessel ( 10 ) is moved by the movement device ( 40 ) or that the holder ( 20 ) is moved with the least one workpiece ( 5 ) in the vessel ( 10 ) by a further movement device independently of the diffuser plate ( 30 ).
15. A diffuser plate ( 30 ) for the apparatus ( 1 ) according to claim 1 .