FLOW GENERATOR, DEPOSITION DEVICE AND METHOD FOR THE DEPOSITION OF A MATERIAL

Abstract

A flow generator has an electrolyte feed device for feeding an electrolyte and an electrolyte distribution device. There is also described a deposition device having such a flow generator and a method for the deposition of a material on a surface of an object.

Claims

1-22. (canceled)

23. A flow generator, comprising: an electrolyte supply apparatus for supplying an electrolyte; and an electrolyte distribution apparatus.

24. The flow generator according to claim 23, wherein said electrolyte distribution apparatus comprises at least one first distributor plate.

25. The flow generator according to claim 24, wherein said electrolyte distribution apparatus comprises at least one further distributor plate arranged opposite said at least one first distributor plate, downstream in a flow direction of the electrolyte.

26. The flow generator according to claim 24, wherein at least one of said distributor plates is a plate formed with openings through which the electrolyte can flow.

27. The flow generator according to claim 24, wherein said electrolyte distribution apparatus comprises at least one distributor pipe disposed opposite said at least one first distributor plate, upstream in a flow direction of the electrolyte, and formed with outlet openings on a side that faces away from said at least one first distributor plate.

28. A deposition device for depositing material on a surface of an object, the deposition device comprising a flow generator according to claim 23, and an object holder for holding the object.

29. The deposition device according to claim 28, wherein said flow generator comprises a housing that is open on one side, with an outflow opening facing said object holder, wherein said housing is connected to an electrolyte supply apparatus so that the electrolyte can be guided by way of the electrolyte supply apparatus into said housing, and wherein said electrolyte distribution apparatus is arranged in said housing.

30. The deposition device according to claim 29, wherein said housing is arranged at a distance of no more than 2 cm from the object holder.

31. The deposition device according to claim 29, wherein a width of said outflow opening of said housing corresponds to at least 80% of a width of an opening of said object holder provided to accommodate the object, and/or a height of said outflow opening corresponds to at least 80% of a height of the opening of said object holder provided to accommodate the object.

32. The deposition device according to claim 28, further comprising: an anode through which the electrolyte can flow arranged between said electrolyte distribution apparatus and said object holder; said anode being dimensioned with a width that corresponds to at least 80% of a width of an opening of the object holder provided to accommodate the object and/or with a height that corresponds to at least 80% of a height of the opening of the object holder provided to accommodate the object.

33. The deposition device according to claim 32, wherein said flow generator comprises a flow baffle arranged between said anode and said object holder for a partial screening of an electrolyte flow and/or for partial screening of electric field lines originating from said anode.

34. The deposition device according to claim 28, wherein said object holder comprises a plurality of contact points for electrically contacting the object distributed equidistantly over an edge of an opening of said object holder provided to accommodate the object.

35. The deposition device according to claim 28, further comprising an overflow basin with an overflow weir and a drain pipe for drawing the electrolyte away from said overflow basin, and wherein said flow generator is arranged in said overflow basin.

36. The deposition device according to claim 35, further comprising: a retention basin in which at least a part of said overflow basin is arranged; a first pump connected to said retention basin for pumping the electrolyte away from said retention basin and for conveying the electrolyte pumped out of said retention basin to said electrolyte supply apparatus of said flow generator; and a second pump connected to said drain pipe for pumping the electrolyte out of said drain pipe and for conveying the electrolyte pumped out of said drain pipe into said retention basin.

37. The deposition device according to claim 28, wherein said flow generator is one of two flow generators and said object holder is arranged between said two flow generators.

38. A method for depositing a material onto a surface of an object, the method which comprises bringing an electrolyte to the surface of the object.

39. The method according to claim 38, which comprises developing a flow of the electrolyte that is directed parallel or substantially parallel to a surface normal of the surface of the object.

40. The method according to claim 39, which comprises bringing the electrolyte to the surface of the object by way of the flow of the electrolyte.

41. The method according to claim 39, which comprises diverting the flow and guiding away the flow of the electrolyte along the surface of the object.

42. The method according to claim 39, which comprises diverting a part of the flow of the electrolyte upward to form an upwardly directed partial flow, and diverting a further part of the flow of the electrolyte downward to form a downwardly directed partial flow, and adjusting a volumetric flow rate of the downwardly directed partial flow such that the volumetric flow rate of the downwardly directed partial flow equals, or substantially equals, a volumetric flow rate of the upwardly directed partial flow.

43. The method according to claim 38, wherein an electrolyte flow directed at the object flows onto the object both at a front side and a rear side of the object, and adjusting a volumetric flow rate of a front-side electrolyte flow and of a rear-side electrolyte flow to be substantially equal.

44. The method according to claim 38, wherein the method is a galvanic coating method in which a layer of a metal is deposited onto the object.

Description

[0069] The invention is explained in more detail below with reference to figures. Whenever expedient, elements that are identical or have the same effect are here given the same reference signs. The invention is not restricted to the embodiments illustrated in the figures—this refers also to functional features. The description given so far and the subsequent description of the figures contain numerous features, some of which are summarized as groups in the dependent claims. A person skilled in the art will, however, also consider the features individually and combine them into useful further combinations. These features can in particular be combined, individually and in any appropriate combination, with the flow generator according to the invention and/or the deposition device according to the invention and/or the method according to the invention.

[0070] Here:

[0071] FIG. 1 shows a schematic illustration of deposition device according to a first exemplary embodiment of the invention;

[0072] FIG. 2 shows a front view of an object holder of the deposition device and an object to be coated that is fastened releasably to the object holder;

[0073] FIG. 3 shows a schematic illustration of a deposition device according to a second exemplary embodiment of the invention;

[0074] FIG. 4 shows a schematic illustration of a deposition device according to a third exemplary embodiment of the invention.

[0075] FIG. 1 shows a schematic illustration of a deposition device 1. The deposition device 1 serves for the deposition of a material, in particular for the galvanic deposition of a metal layer on a surface of an object.

[0076] The deposition device 1 comprises two flow generators 2a, 2b with the same design as each other, as well as a vertically suspended object holder 3 at which an object 4 to be coated is releasably fastened. As can be seen from FIG. 1, the two flow generators 2a, 2b are arranged with mirror symmetry with reference to the object holder 3. For the sake of terminological distinction, the two flow generators 2a, 2b will sometimes be referred to below as the first flow generator 2a and the second flow generator 2b.

[0077] In the present exemplary embodiment, the object 4 that is to be coated is a substrate, in particular a ceramic substrate, with elements arranged thereon such as, for example, active or passive semiconductor components, and a thin metal base layer surrounding the substrate. The object to be coated has a rectangular shape, and has an edge length of about 200 mm and a thickness between 200 μm and 1000 μm. Said metal base layer (also sometimes known in expert circles as the “seed layer”) surrounds the full area of the substrate, including over the substrate edges.

[0078] In the present case, the metal base layer is a copper layer, in particular a masked and structured copper layer. The metal base layer is reinforced in a galvanic deposition process with the aid of the deposition device 1. This means that, in the present exemplary embodiment, copper is deposited with the aid of the deposition device 1 onto the existing copper layer, which forms the metal base layer.

[0079] It should be obvious that the previously mentioned features of the object 4 are merely to be deemed as exemplary, and that the deposition device 1 is in principle suitable for coating other kinds of object.

[0080] In addition to the two flow generators 2a, 2b the deposition device 1 comprises an overflow basin 5 with an overflow weir 6. Both flow generators 2a, 2b are arranged in the overflow basin 5. FIG. 1 shows the deposition device 1 in a state in which the overflow basin 5 is filled up to the edge of its overflow weir 6 with an electrolyte 7.

[0081] The deposition device 1 further comprises a retention basin 8 in which the overflow basin 5 is arranged. The deposition device 1 further comprises a drain pipe 9 provided with holes whose longitudinal extent runs in a horizontal direction and that is arranged underneath the object holder 3 in such a way that the drain pipe 9 and the object holder 3 have a common symmetry plane.

[0082] The two flow generators 2a, 2b of the deposition device 1 each comprise a housing 10 arranged at a distance from the object holder 3 and open on one side, with an outflow opening 11 that faces toward the object 4 to be coated. The two flow generators 2a, 2b each also comprise an electrolyte supply apparatus 12 and an electrolyte distribution apparatus 13.

[0083] The electrolyte distribution apparatus 13 of the respective flow generator 2a, 2b comprises a first distributor plate 14 and a further distributor plate 15, wherein the two distributor plates 14, 15 are arranged parallel to one another as well as parallel to the object holder 3, and are implemented as perforated plates with openings through which electrolyte 7 can flow.

[0084] As can be seen in FIG. 1, the two distributor plates 14, 15 of the respective flow generators 2a, 2b are arranged in its housing 10. The two distributor plates 14, 15 of the respective flow generator 2a, 2b divide its housing 10 into a first chamber 16, a second chamber 17 and a flow channel 18, wherein the first chamber 16 extends from a side wall 19 of the housing 10 that is arranged parallel to the outflow opening 11 to the first distributor plate 14, the second chamber 17 extends from the first distributor plate 14 to the second distributor plate 15, and the flow channel 18 extends from the second distributor plate 15 over the remaining part of the housing 10.

[0085] In each of the two housings 10 the deposition device 1 also comprises a lattice anode 20 through which electrolyte 7 can flow, arranged between the electrolyte distribution apparatus 13 of the respective flow generator 2a, 2b and the object holder 3.

[0086] Both the respective anode 20 and the outlet opening 11 of the respective housing 10 are dimensioned such that their width and height correspond approximately to the width and height of the object 4 to be coated. The term “width” relates here to an extent perpendicular to the plane of the drawing of FIG. 1.

[0087] The deposition device 1 further comprises a first pump 21 for pumping the electrolyte 7 out of the retention basin 8 and for conveying the electrolyte 7 pumped out of the retention basin 8 to the electrolyte supply apparatus 12 of the respective flow generator 2a, 2b. The deposition device 1 further comprises a second pump 22 for pumping the electrolyte 7 out of the drain pipe 9, as well as for conveying the electrolyte 7 that has been pumped out of the drain pipe 9 into the retention basin 8. The first pump 21 is connected via a fluid line 23 to the retention basin 8, and via a further fluid line 23 to the electrolyte supply apparatuses 12 of the two flow generators 2a, 2b, while the second pump 22 is connected via a fluid line 23 to the drain pipe 9 and via a further fluid line 23 to the retention basin 8.

[0088] The deposition device 1 further comprises a flow rate sensor 24 for each of its pumps 21, 22 for measuring a volumetric flow rate of an electrolyte flow that is flowing through the respective pump 21, 22.

[0089] The deposition device 1 moreover comprises a separate DC voltage source 25 for each of its flow generators 2a, 2b. The respective DC voltage source 25 is connected, as can be seen in FIG. 1, via electrical cables 26 to the anode 20 arranged in the associated flow generator 2a, 2b as well as to the object holder 3.

[0090] The respective flow generator 2a, 2b further comprises in its housing 10 a flow baffle 27 that is arranged between the anode 20 arranged in the housing 10 of the respective flow generator 2a, 2b and the object holder 3, and which serves for partially screening an electrolyte flow and for partially screening electric field lines originating from the anode 20.

[0091] FIG. 2 shows a frontal view of the previously mentioned object holder 3 as well as the object 4 that is to be coated, fastened releasably to the object holder 3.

[0092] The object holder 3 is designed as a frame, and has an opening provided to accommodate the object 4, although it is not visible in FIG. 2 since the object 4 that is to be coated is arranged therein.

[0093] One side of the object holder 3 (referred to below as the front side of the object holder 3) is visible in FIG. 2, while the other side of the object holder 3 faces away from the observer. Consequently again, only one side (referred to below as the front side of the object 4) of the object 4 that is to be coated and its surface 28 that is to be coated is visible in FIG. 2.

[0094] The object holder 3 has a plurality of contact points 29, in the present case eight contact points 29, on its front side for electrically contacting the object 4, and these are in electrical contact with the edge 30 of the object 4 at its front side. On its rear side, not visible in FIG. 2, the object holder 3 has the same number of contact points 29 for electrically contacting the object 3, and these are in electrical contact with the edge 30 of the object 4 at its rear side. The front-side contact points 29 are electrically connected to one of the two DC voltage sources 25, while the rear-side contact points 29 are electrically connected with the other of the two DC voltage sources 25.

[0095] Both on the front side and on the rear side of the object holder 3 the contact points 29 are arranged distributed equidistantly over the edge of the opening of the object holder 3 provided to accommodate the object 4, and thus also equidistantly over the edge 30 of the object 4.

[0096] The mode of operation of the deposition device 1 is described below with reference to FIG. 1. Since, as previously explained, the two flow generators 2a, 2b are designed with the same construction as one another, the mode of operation of the deposition device 1 is described, for the sake of simplicity, by way of example with reference to one of the two flow generators 2a, 2b, or, put more precisely, with reference to the first flow generator 2a. The following explanations apply analogously to the second flow generator 2b. This means that both flow generators 2a, 2b are used in order to subject the object 4 to be coated to the flow of electrolyte 7, so that the object 4 is homogeneously coated on both sides.

[0097] With the aid of the first pump 21, the electrolyte 7 is introduced via the electrolyte supply apparatus 12 of the first flow generator 2a into the housing 10 of the first flow generator 2a, or, put more precisely, into the first chamber 16 of the housing 10. An electrolyte flow 31 develops in the first chamber 16, which flows through the first distributor plate 14 and is thus prehomogenized by the first distributor plate 14. The prehomogenized electrolyte flow 31 then flows through the second chamber 17 of the housing 10 as well as the further distributor plate 15, and the electrolyte flow 31 is further homogenized as it flows through the further distributor plate 15. The homogenized electrolyte flow 31 then flows out of the flow channel 18 of the housing 10 via the outflow opening 11 of the housing 10 perpendicularly, or essentially perpendicularly, to the object to be coated 4.

[0098] The electrolyte flow 31 is diverted at the surface 28 that is to be coated of the object 4, and guided away from the object 4 parallel, or essentially parallel, to said surface 28. One part of the electrolyte flow 31 is diverted upward, and forms an upwardly directed partial flow 32a. A further part of the electrolyte flow 31 is diverted downward, and forms an downwardly directed partial flow 32b. Said partial flows 32a, 32b flow away through a gap between the object holder 3 and the housing 10 of the first flow generator 2a.

[0099] The volumetric flow rate of the downwardly directed partial flow 32b is adjusted such that the volumetric flow rate of the downwardly directed partial flow 32b is the same as the volumetric flow rate of the upwardly directed partial flow 32a. This can, for example, be achieved in that the conveying rates of the two pumps 21, 22 are adjusted such that the two flow rate sensors 24 measure the same volumetric flow rate.

[0100] The downwardly directed partial flow 32b flows through the holes of the drain pipe 9 into the drain pipe 9, while the upwardly directed partial flow 32a flows out of the overflow basin 5 over the overflow weir 6. The electrolyte 7 is pumped out of the drain pipe 9 with the aid of the second pump 22, and conveyed into the retention basin 8. The electrolyte 7 that is in the retention basin 8 is pumped out of the retention basin 8 with the aid of the first pump 21, and conveyed to the electrolyte supply apparatus 12 of the first flow generator 2a.

[0101] An electric voltage is present between the anode 20 that is arranged in the housing 10 of the first flow generator 2a and the object holder 3. Since the object 4 is in electrical contact with the object holder 3 via the contact points 29, the same voltage is also present between said anode 20 and the object 4. There is consequently an electric field between said anode 20 and the object holder 3, as a result of which ions contained in the electrolyte 7 are guided to the object to be coated 4. Because of the previously described design of the anode 20 and of the object holder 3, this electric field has homogeneous electric field lines, so that the object 4 is subjected to a homogeneous stream of ions.

[0102] The description of the following exemplary embodiments is primarily limited to the differences from the preceding exemplary embodiment, to which reference is made in respect of identical features and functions. Features of the preceding exemplary embodiment are adopted into the following exemplary embodiments without being described again.

[0103] FIG. 3 shows a schematic illustration of a second deposition device 33 for depositing material, in particular for the galvanic deposition of a metal layer onto a surface of an object.

[0104] This deposition device 33 again comprises a first and a second flow generator 2a, 2b, wherein the two flow generators 2a, 2b are designed with the same construction as each other.

[0105] In the present exemplary embodiment, the electrolyte distribution apparatus 13 of the respective flow generator 2a, 2b does not comprise two distributor plates, but only a single distributor plate 14. In addition to its distributor plate 14, the electrolyte distribution apparatus 13 of the respective flow generator 2a, 2b comprises a distributor pipe 34 that is arranged between the distributor plate 14 and the side wall 19 of the housing 10 that is arranged parallel to the outflow opening 11, and has a plurality of outlet openings on its side that faces away from the distributor plate 14, or the side that faces toward the side wall 19. The distributor pipe 34 of the respective flow generator 2a, 2b is connected to this electrolyte supply apparatus 12.

[0106] Since the two flow generators 2a, 2b of the deposition device 33 are designed with the same construction as one another, the mode of operation of the deposition device 33 is described, for the sake of simplicity, by way of example with reference to one of the two flow generators 2a, 2b or, put more precisely, with reference to the first flow generator 2a. The following explanations apply analogously to the second flow generator 2b.

[0107] With the aid of the first pump 21 of the deposition device 33, the electrolyte 7 is introduced via the electrolyte supply apparatus 12 of the first flow generator 2a into the distributor pipe 34 of the first flow generator 2a. The electrolyte 7 emerges from the outlet openings of the distributor pipe 34 from the distributor pipe 34, wherein a prehomogenized electrolyte flow 31 is developed. This prehomogenized electrolyte flow 31 meets the side wall 19 of the housing 10 of the first flow generator 2a, is diverted there and flows from the side wall 19 further to the distributor plate 14. The electrolyte flow 31 then flows through the distributor plate 14, and the electrolyte flow 31 is further homogenized as it flows through the distributor plate 14. After the distributor plate 14, the homogenized electrolyte flow 31 then flows via the outflow opening 11 of the housing 10 perpendicularly, or essentially perpendicularly, to the object to be coated 4. In other respects, the mode of operation of the deposition device of FIG. 3 corresponds to that of the deposition device of FIG. 1.

[0108] FIG. 4 shows a schematic illustration of a third deposition device 35 for depositing material, in particular for the galvanic deposition of a metal layer onto a surface of an object.

[0109] This deposition device 35 again comprises an overflow basin 5 and a retention basin 8, wherein, in the present exemplary embodiment, only a part of the overflow basin 5, or, put more precisely, only the upper part of the overflow basin 5, is arranged inside the retention basin 8.

[0110] The deposition device 35 of FIG. 4 does not comprise two pumps, but only a single pump 21. In addition, the deposition device 35 comprises a reservoir 36 and valve 37.

[0111] Said pump 21 is connected on the inlet side via a fluid line 23 to the reservoir 36, and on the outlet side via a further fluid line 23 to the electrolyte supply apparatuses 12 of the two flow generators 2a, 2b. The reservoir 36 is connected on the inlet side via a fluid line 23 to the retention basin 8, and via a further fluid line 23, to which a flow sensor 38 is connected, to the drain pipe 9.

[0112] In the present exemplary embodiment, the electrolyte 7 that is in the retention basin 8, as well as the electrolyte 7 that is in the drain pipe 9, is drawn away from the retention basin 8 and from the drain pipe 9 with the aid of gravity. With the aid of said valve 37, or, put more precisely, through an appropriate adjustment of the valve position, it is possible to ensure that the volumetric flow rate of a partial flow of the electrolyte 7 leaving the overflow basin 5 by way of the drain pipe 9 is the same as the volumetric flow rate of a partial flow of the electrolyte 7 leaving the overflow basin 5 via the overflow weir 6.

[0113] Whether the volumetric flow rate of the partial flow leaving the overflow basin 5 by way of the drain pipe 9 is the same as the volumetric flow rate of the partial flow leaving the overflow basin 5 by way of the overflow weir 6 can be established by means of the two flow sensors 24, 38 of the deposition device 35. If the flow sensor 38 that is connected to the fluid line 23 between the reservoir 36 and the drain pipe 9 measures a value that is half as large as the other flow sensor 24 that is connected to the fluid line 23 between the pump 21 and the electrolyte supply apparatuses 12 of the two flow generators 2a, 2b, then the volumetric flow rate of the partial flow leaving the overflow basin 5 by way of the drain pipe 9 is equal to the volumetric flow rate of the partial flow leaving the overflow basin 5 by way of the overflow weir 6.

[0114] The electrolyte 7 is pumped out of the reservoir 36 with the aid of the pump 21 and is conveyed to the electrolyte supply apparatuses 12 of the two flow generators 2a, 2b.

[0115] The invention has been described in detail with reference to the illustrated embodiments. The invention is nevertheless not limited to or by the disclosed examples. Other variations can be derived by the person skilled in the art from these exemplary embodiments without deviating from the thinking underlying the invention.

LIST OF REFERENCE SIGNS

[0116] 1 Deposition device

[0117] 2a Flow generator

[0118] 2b Flow generator

[0119] 3 Object holder

[0120] 4 Object

[0121] 5 Overflow basin

[0122] 6 Overflow weir

[0123] 7 Electrolyte

[0124] 8 Retention basin

[0125] 9 Drain pipe

[0126] 10 Housing

[0127] 11 Outflow opening

[0128] 12 Electrolyte supply apparatus

[0129] 13 Electrolyte distribution apparatus

[0130] 14 Distributor plate

[0131] 15 Distributor plate

[0132] 16 Chamber

[0133] 17 Chamber

[0134] 18 Flow channel

[0135] 19 Side wall

[0136] 20 Anode

[0137] 21 Pump

[0138] 22 Pump

[0139] 23 Fluid pipe

[0140] 24 Flow sensor

[0141] 25 DC voltage source

[0142] 26 Electrical cable

[0143] 27 Flow baffle

[0144] 28 Surface

[0145] 29 Contact point

[0146] 30 Edge

[0147] 31 Electrolyte flow

[0148] 32a Partial flow

[0149] 32b Partial flow

[0150] 33 Deposition device

[0151] 34 Distributor pipe

[0152] 35 Deposition device

[0153] 36 Reservoir

[0154] 37 Valve

[0155] 38 Flow sensor