WO2019078712A1

WO2019078712A1 - Method for applying a layer on a part of a substrate surface

Info

Publication number: WO2019078712A1
Application number: PCT/NL2018/050679
Authority: WO
Inventors: Henricus Gerardus Maria VERVOORT; Augustinus Cornelis Maria Van De Ven
Original assignee: Meco Equipment Engineers B.V.
Priority date: 2017-10-17
Filing date: 2018-10-16
Publication date: 2019-04-25
Also published as: NL2019743B1; TW201928122A

Abstract

The invention relates to a method for applying a layer on a substrate surface, comprising applying the layer on a plating part of the substrate surface by plating to which end the plating part is brought into contact with an electrolyte. A first part of the part of the substrate surface situated outside the plating part is kept free from contact with the electrolyte, wherein a second part, which at least partly deviates from the first part, of the part of the substrate surface situated outside the plating part is masked during application of the layer by plating due to a masking layer having been printed thereon by means of inkjet printing, with the plating part adjoining the second part.

Description

Title: Method for applying a layer on a part of a substrate surface

Description

The invention relates to a method for applying a layer on a plating part of a substrate surface in which the layer is applied on the plating part of the substrate surface by plating, to which end the plating part is brought into contact with an electrolyte. The term plating part is understood to mean the part of the substrate surface which is to be covered with the layer and which will be covered with the layer after application of the method. An electrolyte is a liquid in which metal ions have been dissolved. The expression by plating is understood to mean the process in which the metal ions dissolved in the electrolyte adhere to the plating part of the substrate surface during application of the layer. The layer may be made, for example, of tin, gold, silver, palladium, nickel, gallium, indium, zinc, lead, copper or cobalt. The plating may be performed both electroless and by electrolysis. When applying the layer by electrolysis, a cathode voltage is applied on the substrate in order to deposit the metal ions from the electrolyte. The plating part does not involve the entire substrate surface, but only a part thereof. The plating part may be formed by a number of areas on the substrate surface which do not adjoin one another, but may also be formed by a continuous area.

The invention aims to provide a method by means of which, on the one hand, both the material of the layer and the material which is used and consumed during application of the method or before or after are used in an efficient manner. On the other hand, the invention aims to provide a method by means of which it is possible to apply the layer on the plating part with a great degree of accuracy. To this end, the invention provides a method according to the preamble wherein a first part of the part of the substrate surface situated outside the plating part is kept free from contact with the electrolyte, wherein a second part, which at least partly deviates from the first part, of the part of the substrate surface situated outside the plating part is masked during application of the layer due to a masking layer having been printed thereon by means of inkjet printing, with the plating part adjoining the second part. By means of inkjet printing, it is possible to produce an accurate delimitation for the plating part of the substrate surface, as a result of which it is also possible to apply the layer with a great degree of accuracy on the plating part. The surface of the second part of the substrate surface situated outside the plating part is thus formed by the printed masking layer. By keeping the first part of the part of the substrate surface situated outside the plating part free, it is not necessary to provide the entire surface of the substrate, insofar as that is situated outside the plating part of the substrate surface, with a masking layer by means of inkjet printing, which may, in practice, be an unattractive option from a commercial point of view. In addition, the first part of the part of the substrate surface situated outside the plating part may be used to provide an electrical contact via this first part in order to apply a cathode voltage to the substrate in case the plating of the layer is performed by electrolysis. The second part on which the masking layer is provided may thus only be used where a great degree of accuracy is required which may offer both technical and commercial advantages. The first part may be used where no great degree of accuracy is required. In order to prevent misunderstandings, it should be noted that neither the first part, nor the second part involve the entire surface of the substrate insofar as situated outside the plating part. The first part is thus formed by only a part of the entire surface of the substrate insofar as situated outside the plating part, while the second part is formed by only another part of the entire surface of the substrate insofar as situated outside the plating part, in which case it is possible for the first part and the second part to partly overlap. In general, the aim when carrying out the method according to the invention will be to reduce the size of the second part as masking by means of a printed masking layer in order to prevent undesirable deposition of metal ions outside the plating part is relatively more expensive than other measures which could be taken to this end, such as for the purpose of keeping the part of the substrate surface situated outside the plating part free from contact with the electrolyte or by simply keeping it beyond the range of the respective part of the electrolyte or by masking by means of a masking body, as will be explained below. However, in any case, the options to reduce the size of the second part will in practice greatly depend on the form of the substrate and the position and size of the plating part. Thus, in practice, the size of the second part will often in any case have to be at least 5% of the size of the part of the substrate surface situated outside the plating part, which percentage may also be significantly higher, for example more than 80%.

In one embodiment, the plating part does not adjoin the first part in order to achieve a relatively high accuracy.

In one embodiment, the first part of the surface and the second part of the surface partly overlap in order to prevent the undesirable growth of a layer between the first part and the second part. In this case, the region of overlap involves preferably at most 15 % of the part of the substrate surface situated outside the plating part in order to reduce the amount of material required for the printed masking layer.

In particular the commercial advantages of the invention can often be used in an optimum manner in practice if the size of the first part of the surface is greater than the size of the second part of the surface. The invention may furthermore be used advantageously if the substrate is panel-shaped or is at least made of panel- shaped material. In this case, it is not necessary for the substrate to be flat. The invention is also particularly suitable for use with a panel-shaped substrate which is partly, or even completely, bent. The invention is suitable for use with both panel- shaped substrates in which the plating part is situated on only one side of the substrate and with substrates in which the plating part is situated on two sides of the substrate.

It is possible to achieve an advantageous use of the invention if the plating part is situated on an, at least substantially, projecting part of the substrate. The layer which can, according to the invention, in this case be applied on the plating part of the substrate may serve, for example, as a bonding layer for a solder connection for which purpose the layer is made, for example, of tin or as a contact pad for a plug connection, to which end the layer is made of, for example, a noble metal, such as gold, silver or palladium.

In one embodiment, the projecting part has a cross section of which the masking layer is printed on a part of the periphery thereof and the layer is applied on another part of the periphery thereof by plating.

More specifically, it is in this case possible for the cross section to have a rectangular shape or at least have four edges adjoining each other between neighbouring longitudinal sides, wherein the rectangular shape is determined by four longitudinal sides of the projecting part, wherein the plating part extends over at least a part of a first longitudinal side, wherein a third longitudinal side is situated opposite the first longitudinal side and the masking layer is provided on the second longitudinal side which adjoins both the first longitudinal side and the third longitudinal side, and/or on the fourth longitudinal side which likewise adjoins both the first longitudinal side and the third longitudinal side. Thus, it is not necessary to provide the entire surface of the projecting part with a layer by plating.

If the plating part extends only over a part of the first longitudinal side and the masking layer is also provided on the first longitudinal side and then in particular if the plating part is situated at a distance from the periphery of the first longitudinal side over its entire periphery and/or if the masking layer is also provided on the third longitudinal side and/or if the projecting part, at a free end thereof, has an end side on which the masking layer is printed, the size of the layer may be reduced to the dimensions which are necessary for it to function. Thus, the material of the layer, which material, for example a noble metal, is often relatively expensive, may be used in an efficient manner.

The invention is suitable to be used in an embodiment in which the plating part is a bent part of the substrate surface and/or in which the second part is a bent part of the substrate surface. Such a situation may exist, for example, if the abovementioned projecting part is bent, for example at its free end. Bending the projecting part may take place both before the masking layer is printed on the second part and after.

Overall, the invention is also suitable for use with band-shaped or strip-shaped substrates.

With the method according to the invention, the substrate may be suspended from a band-shaped carrier during application of the layer, for example by means of clamping members which clamp the substrate against the carrier, as is known per se to those skilled in the art, and/or the substrate may be transported during application of the layer.

A practical embodiment of the method according to the invention may be achieved if the first part is at least partly masked by at least one masking body during application of the layer, to which end the at least one masking body is positioned against the first part before application of the layer and is moved away from the first part after application of the layer. By means of the masking body, the first part of the substrate surface can be kept free from contact with the electrolyte in a very effective and efficient manner.

It is possible to achieve a considerable saving on the amount of ink required if the at least one masking body is also positioned against a part of the second part before application of the layer and is also moved away from that part of the second part after application of the layer. Thus, there is a case of overlap, namely to a degree which is determined by the accuracy with which the at least one masking body can be positioned against the substrate, between the printed second part of the surface and the second part of the surface masked by the at least one masking body. In particular, if the substrate is band-shaped, the method can be carried out efficiently if the at least one masking body comprises at least two belts which, at a distance apart, mask edges of the substrate which are situated opposite each other. Between the two belts, there is then a strip-shaped area where the plating part is at least partly situated. In addition to the plating part, at least a part of the printed part of the surface is also situated in the strip-shaped area.

The plating part is situated completely between the two belts if the at least one masking body comprises a belt which is closed, in other words does not comprise any openings.

Alternatively, it is also possible for the at least one masking body to comprise a belt which comprises openings, wherein the second part of the surface partly extends inside the openings during application of the layer. The accuracy with which the layer can be applied on the substrate is then not primarily determined by the accuracy with which the belt is positioned against the substrate, as is the case with the prior art from US 2006/0226017 A1 , but by the accuracy with which the masking layer is printed on the substrate.

The at least one masking body can move along with the substrate during transportation thereof during application of the layer.

Furthermore, the use of a masking body makes it possible for the substrate to be completely immersed in the electrolyte which may benefit the simplicity of the process.

In one embodiment, it is also possible for the plating part to be immersed in the electrolyte and for the first part to be, at least partly, held above the electrolyte in order to apply the layer. Insofar as the first part is immersed, a masking body could be used for the first part, as is explained above.

In case the first part is held completely above the electrolyte, this effectively results in the first part being kept free from contact with the electrolyte.

It is also possible for the second part to be partly held above the electrolyte, as a result of which it is possible to prevent, with a higher degree of certainty, a layer from inadvertently forming on the substrate above the electrolyte or at least above the level at which the electrolyte is normally. The actual highest level of the electrolyte may be above the normal level, due to, for example, wave action.

In an embodiment which can be implemented relatively simply, a cathode voltage is applied to the substrate via the first part in order to apply the layer on the plating part of the substrate surface. In that case, the application of the layer by plating involves applying the layer by electrolysis. The cathode voltage will reduce the metal ions from the electrolyte, so that these are deposited on the plating part.

In case of a partial or complete immersion of the substrate in the electrolyte and of applying the layer by electrolysis, it is preferred if the cathode voltage is applied via a position above the electrolyte.

The contact between the plating part of the substrate surface and the electrolyte may also be brought about by supplying electrolyte to the plating part in order to apply the layer instead of by immersing it in the electrolyte.

In this case, in a practical embodiment, the electrolyte is supplied to the plating part via a contact member which is in contact with the plating part at the periphery thereof, which contact member optionally rotates and partly extends into the electrolyte. In the optional situation in question, electrolyte is continuously absorbed by the contact member and, due to the rotation, supplied to the plating part which is situated outside the electrolyte.

Alternatively, it is also possible for the contact member to be stationary, for example to be of the cloth type, brush type or sponge type, wherein the electrolyte is supplied to the stationary contact member. In this case, the substrate may be transported along the contact member in a dragging manner, in which case the substrate is brought into contact with the electrolyte via the contact member, as is the case, for example, with so-called brush-plating.

In general, it will be preferred to remove the masking layer from the surface after application of the layer. This may be effected, for example, by stripping the masking layer, as is known per se to a person skilled in the art.

The method according to the invention may comprise the active step of printing the masking layer on the second part of the substrate surface by means of inkjet printing before application of the layer on the plating part. Obviously, it is also possible to already provide the masking layer at the start of the method in a state in which the masking layer has already been printed thereon by means of inkjet printing. This may have been carried out by a different party and optionally also in a different country.

In particular for the application of layers on bent parts and/or on surfaces oriented at an angle with respect to each other and adjoining each other, for example of a projecting part of a substrate, in one embodiment, the masking layer is printed on the second part of the substrate surface by means of a printhead whose orientation with respect to the substrate changes during printing.

The invention also relates to a substrate obtained by means of a method according to the invention, as explained above.

The present invention will be explained in more detail by means of the description of a number of possible embodiments of the invention with reference to the following figures, in which:

Fig. 1 shows, in isometric view, an embodiment of a device for carrying out the method according to the invention;

Fig. 2 shows, in a cross section l l-l l according to Fig. 3, the bath such as that which forms part of the device according to Fig. 1 ;

Fig. 3 shows, in isometric view, a substrate such as that which is treated in the bath according to Fig. 2;

Fig. 4 shows a frontal view of the substrate according to Fig. 4;

Figs. 5a to 5d show, in isometric views, successive stages while the method according to the invention is being carried out, at the location of pin-shaped ends of a substrate;

Fig. 6 diagrammatically shows a vertical cross section of a second embodiment of a device by means of which the method according to the invention can be carried out;

Figs. 7a and 7b each show, in isometric view, the same cross- sectional part from Fig. 6 with two different substrates;

Fig. 8 diagrammatically shows, in vertical cross section, a third embodiment of a device according to the invention for carrying out the method according to the invention.

Device 1 according to Fig. 1 shows a transport system comprising a carrying band 2 which is wound around two pulleys 3, 4. In use, one of the two pulleys 3, 4 is driven so as to rotate about its central axis by drive means which are not shown in any more detail. Immediately downstream of pulley 3, at the location of reference numeral 24, substrates 5 may be suspended from the carrying band 2 in an automated fashion by means of sprung wire clamps 6 (see Fig. 2). Immediately upstream from pulley 4, at the location of reference numeral 44, these substrates 5 may again be removed from carrying band 2 in an automated fashion.

Fig. 1 shows two substrates 5. While the substrates 5 are transported while being suspended from carrying band 2, they are passed through a bath 7 containing an electrolyte 8. At the two opposite ends of bath 7, bath 7 is provided with locks (not shown in any more detail), via which locks the substrates 5 are successively moved into the bath 7 and moved out of the bath 7 again, as a result of the transporting activity of the transport system. As has been described above, devices such as device 1 are known per se to a person skilled in the art, for which reason a more detailed description may be omitted here.

In the present example, substrates 5 have a plating part on one side which is configured as small square areas 9 which are arranged in three parallel rows, which small areas 9 are intended to be coated with a metallic layer by plating, more specifically by electrolysis. Apart from an top strip-shaped part 10 of substrate 5, the part of the surface of the substrate 5 situated outside the small areas 9 is provided with a masking layer 1 1 which is printed on the substrate 5 by means of inkjet printing. All small areas 9 are thus completely surrounded by the masking layer 1 1 . The liquid level of electrolyte 8 is chosen such that all small areas 9 are in any case immersed in the electrolyte 8, so that they can be exposed to the plating/electrolytical action of the electrolyte 8. The unprinted part 10 of substrate 5 is situated completely above, or outside, the electrolyte 8 in bath 7, so that the unprinted part 10 of substrate 5 is not exposed to the plating/electrolytical action of the electrolyte 8 in bath 7. A top edge of the masking layer 1 1 , denoted by reference numeral 1 1 ', is situated just above the electrolyte 8. The unprinted part 10 situated above the electrolyte 8 is used to apply a cathode voltage to the substrate 5 via the abovementioned clamps 6, so that the metal ions in the electrolyte 8 are attracted by the substrate 5 at the location of the small areas 9 and will adhere to these small areas 9.

Fig. 2 shows the bath 7 of device 1 in vertical cross section. Substrates 15, which are illustrated in Figs. 3 and 4 in isometric and in front view, respectively, are suspended from carrying band 2 by means of filament-type spring clamps 6 provided at equal distances from one another in the length direction of carrying band 2. Substrate 15 relates to a lead frame with ten inwardly directed projecting parts 16 which, on areas 17 at their respective free ends and on areas 18 at longitudinal positions situated between the ends of the projecting parts 16, have to be metallized, for example with tin or gold, in order to make it possible to bring about a soldered connection between the projecting parts 16, more specifically between each of the areas 17 and 18 on the one hand and an electrically conductive wire on the other hand or to form a contact pad for a plug connection or solder connection. Metallizing takes place by electrolysis, to which end the substrate 15 is largely immersed in the electrolyte 19.

Outside the areas 17 and 18 which are intended to be plated, the substrate 15 is virtually completely printed with a masking layer 20 which is printed by means of inkjet printing and is shown hatched in Fig. 4. Furthermore, a top strip 21 of the substrate 15 is unprinted. This strip 21 is engaged by the bottom ends of clamps 6 and the substrate 15 is clamped against the underside of the carrying band 2 by clamps 6. Via the clamps 6, which are made of electrically conductive material, the cathode voltage required for application of the metallic layer on the areas 17, 18 by electrolysis is applied to the substrate 15.

As can be seen in Figs. 3 and 4, the areas 17 do not extend across the entire width of the projecting parts 16 at the ends thereof and the ends of the projecting parts 16 are provided with the masking layer 20 near the edges also by means of inkjet printing. Due to the inkjet-printed masking layer 20, the areas 17, 18 can be defined very accurately, as a result of which the consumption of material of the metal with which the areas 17, 18 are plated can be reduced. Incidentally, the masking layer 20 is only shown diagrammatically in Fig. 2 and not to scale.

The level of electrolyte 19 with respect to the substrate 15 has been chosen such that the areas 17, 18 are in any case completely immersed in the electrolyte 19. A small part of the printed masking layer 20 still extends above the electrolyte 19, thus preventing a part of the unprinted strip 21 from nevertheless inadvertently being plated, for example as a result of waves on the surface of the electrolyte 19.

Although in the present example according to Figs. 2, 3 and 4, the largest part of the surface of the substrate 15 is provided with a masking layer 20 by means of inkjet printing, it is also readily possible, with other substrates or at least with substrates comprising other areas which are intended to be plated, to provide a significantly smaller part of the respective substrate with a masking layer by means of inkjet printing and to leave a considerably larger part of the surface of the substrate 15 unprinted, despite the fact that this part would not be intended to be plated. In the present example, it is possible, for example, to imagine that only the areas 17, 18 on the bottom five projecting parts 16 are intended to be plated. In such a situation, for example only the part of the substrate 15 which is situated below line 22 might be provided with a masking layer by means of inkjet printing and the liquid level of the electrolyte 19 could be equal to line 23.

The invention is also suitable for use for applying a layer by plating on specific areas which have a bent shape, as is illustrated in Figs. 5a to 5d. The figures show a bent end 25 of a projecting part 26, similar to a projecting part 16 of the substrate 15. The projecting part 26 has four longitudinal sides 27, 28, 29, 30, the longitudinal side 28 of which is not visible in Figs. 5a to 5d. In cross section, the projecting part 26 has a rectangular shape which is determined by these four longitudinal sides 27-30. The projecting part 26 furthermore has an end side 31.

In functional terms, it is only necessary for the projecting part 26 on the first longitudinal side 27 at the end 25 of projecting part 26 in area 32 to be plated. The periphery of area 32 is at a distance from the edges 33, 34 which connect the first longitudinal side with the second longitudinal side 28 and the fourth longitudinal side 30, respectively, and from the edge 35 via which the first longitudinal side 27 is connected to the end side 31 . Fig. 5b shows how a masking layer 36 is printed on the entire surface of the end 25 of the projecting part 26, with the exception of the area 32, on the projecting part 26 by means of inkjet printing. This masking layer 36 thus covers the second to fourth longitudinal sides 28, 29, 30 at the end 25 and the end side 31 completely and the first longitudinal side 27 partly, namely insofar as it is situated on the outside of the area 32. Printing the various bent surfaces and the various mutually perpendicular surfaces by means of inkjet printing is possible by changing the orientation of the printhead for inkjet printing, so that it is preferably directed perpendicularly or at least as perpendicularly as possible, onto the surface to be printed and/or by suitable manipulation of the respective substrate along the printhead.

The used ink generally in any case has to be resistant to the electrolyte to be used and has to be dielectric, so that the printed layer is not damaged by the electrolyte during the plating process and no metal ions will be deposited. The ink may be, for example, a UV-curing ink on the basis of for example acrylate or polyurethane, a 'hot-melt' ink on the basis of methacrylate or natural resins or a combination of a UV-curing ink and a hot-melt ink. Fig. 5c shows how a metallic layer 37 is applied to the area 32 in a way which has already been described with reference to the description of Figs. 1 to 4. Fig. 5d shows how the masking layer 36 has been selectively removed, as may be achieved, for example, by means of stripping, which is known to a person skilled in the art, in which the metallic layer 37 remains behind on the longitudinal side 27 on the end 25 of the projecting part 26, at a distance from edges 33, 34 and 35.

Fig. 6 shows a device 51 for applying a layer on one side or on two sides on the surface of a band-shaped substrate 52. Device 51 comprises a bath 53 containing electrolyte 54 up to level 55. Device 51 furthermore comprises a wheel unit 56 with two wheel discs 57, 58, the central axes of which coincide (Fig. 7a). On their mutually facing sides, the wheel discs 57, 58 are situated a distance d (Fig. 7b) apart. An inner masking belt 59, 60 is wound around each of the wheel discs 57, 58 which is also wound around a pulley 61 which is situated directly above the wheel unit 56. Furthermore, respective outer masking belts 62, 63 are wound around the two wheel discs 57, 58 on the outside of the two inner masking belts and also around pulleys 64-69. In this example, the widths of the masking belts 59, 60, 62, 63 are identical, but in alternative embodiments, these may also differ from each other. The masking belts 59, 60, 62, 63 are aligned with respect to wheel discs 57, 58 in such a way that the mutually facing sides of respectively the masking belts 59, 62 on one side and the masking belts 60, 63 on the other side are (also) situated a distance d apart.

By means of pulleys 70, 71 , the band-shaped substrate 52 is passed between the pairs of inner masking belts 59, 60 and outer masking belts 62, 63 and clamped in between. In this way, the masking belts 59, 60, 62, 63 mask the longitudinal edges of the band-shaped substrate 52, at least in the area in which the substrate 52 is passed through the electrolyte 54.

The substrate 52 has a width B (Fig. 7b). In the example from Fig. 7a, the substrate 52 is provided on one main side with a strip-shaped central area 75 and on the other main side with a strip-shaped area 76, both of which are intended to be metallized by applying a metal layer thereon by plating. Outside the areas 75, 76, both main sides of the surface of the substrate 52 are provided, within width b (Fig. 7b), with a masking layer 77 which is applied on the substrate 52 by means of inkjet printing. The size of width b is greater than the size of distance d, so that the printed part 77, on two mutually opposite sides of the areas 75 and 76 overlaps the part of the substrate 52 which is clamped between the masking belts 59, 62 and 60, 63. In this way, the surface of the substrate 52 which is situated outside the electrolytical parts 75, 76 is kept free from contact with the electrolyte 54, partly by the masking layer 57, partly by the masking belts 59, 62 and 60, 63 which should be considered as masking bodies, partly by both the masking layer 57 and by the masking belts 59, 62 and 60, 63.

In the example from Fig. 7b, there are no strip-shaped electrolytical parts 75, 76, but square electrolytical areas 81 which are arranged together in a line on one side of the substrate 52 and square electrolytical parts 82 which are not visible in Fig. 7b and are arranged in a line on the opposite side of the substrate 52.

If a metal layer only has to be applied on the inside of the substrate

52, it is also possible, in an alternative arrangement, to use a single outer masking belt instead of the two outer masking belts 62, 63. The positions of the longitudinal edges of such a masking belt would then coincide with the positions of the mutually oppositely facing longitudinal edges of the outer masking belts 62, 63 so that in any case the entire outside of substrate 52, insofar as situated between the wheel discs 57, 58, is protected against the electrolyte 54 by the masking belt.

According to a further alternative embodiment, it is also possible to use a masking belt in which openings are provided which are aligned in such a way with a pattern of areas to plated, such as areas 81 , that these areas fall within the recesses. Thus, the surface of the printed part can be significantly reduced, whereas plating can still be performed accurately and in any case does not depend directly on the accuracy with which the aforementioned alignment between the recesses and the areas to be plated takes place, as long as there is some distance between the periphery of the recesses and the periphery of the areas to be plated.

According to a further variant, which builds on the previous embodiment, it would also be possible to use two successive devices, such as for example device 51 , in which case the substrate 52 is successively (preferably with interim flushing) passed through two different electrolytes in order to apply layers of different metals. In the first bath, it is then possible to protect a first part of the areas to be plated by means of the above-described recesses in a masking belt by the masking belt while the recesses leave another, second part of the areas to be plated free in order to apply a layer of a first metal thereon by plating. In the second bath, it is then in particular the first part of the areas to be plated which can be kept free by recesses in the masking belt associated with the second device, while the masking belt protects the second part, which has then already been plated, from the electrolyte so that a layer of another, second metal is applied by plating on the first part of the areas to be plated.

With the device 100 from Fig. 8, there is no bath containing electrolyte. Device 100 comprises a reel 101 . A band-shaped substrate 102 is passed over the upper half of reel 101 by means of pulleys 103, 104 and guided rollers 105, 106, in which case the substrate 102 bears against the outside of the reel 101 . In use, the reel 101 moves along with the substrate 102 due to the fact that the reel 101 rotates about an axis of rotation which coincides with the central axis of the reel. To this end, either the reel 101 may be provided with an autonomous drive or may be pulled along by the substrate 102 due to friction between the reel 101 and the substrate 102.

In the area of the upper half of reel 101 , the substrate 102 is protected over its entire width by an outer masking belt 107 which is wound around the substrate 102 on the outer sides of the reel 101 by means of pulleys 108, 109, 1 10 and guided roller 1 1 and, in use, moves along with substrate 102. Use of the outer masking belt 107 is necessary in any case if the substrate 102 has passages.

The side of substrate 102 which forms the underside of substrate 102 in Fig. 8, is provided with a masking layer, partly by means of inkjet printing. This printed masking layer completely surrounds areas on the surface of the underside of the substrate 102 which are intended to be provided with a metallic layer by plating, collectively referred to as the plating part. The wall of the reel 101 contains recesses which are not visible in any more detail in Fig. 8 and which leave the areas of the plating part, including a part of the masking layer printed around the respective areas, free. The reel thus acts as a masking body and could also be referred to by the term spot mask. Alternatively, reel 101 could also be provided with a continuous recess in which case the reel 101 would in fact consist of two coaxial parts which are situated a distance apart in order to leave a strip-shaped part on the substrate free, on which strip-shaped part, insofar as it is not a plating part, a masking layer is printed. Such a reel could be referred to by the term line mask.

Insofar as the underside of substrate 102 is left free by the recesses, this is either an area or areas associated with the plating part, or a part of the printed masking layer. Another part of the printed masking layer also extends on the outer sides of the recesses in the wall of the reel, so that masking is performed in these overlapping areas by both the wall of the reel itself and by the other part of the printed masking layer. The upper side of the substrate 102 is not provided with a printed masking layer, but is completely protected by the masking belt 107, so that it is not possible for electrolyte to reach the upper side of the substrate 102 if the substrate 102 itself has open passages. In case substrate 102 is completely closed, the use of the masking belt 107 is not necessary.

Electrolyte is continuously supplied to the underside of the substrate 102 via the recesses, as a result of which a layer is deposited on the areas of the plating part which areas are accurately defined because of the masking layer which is printed around the areas by means of inkjet printing.

According to a further variant, the invention may also be used with the so-called brush-plating or tampon-plating, by means of which technique a part of a substrate surface is selectively provided with a metal layer by plating. The accuracy of this technique is limited. During brush-plating, a contact member, such as a brush or cloth, is brought into contact locally with a limited area of the substrate surface. The substrate surface, insofar as it is situated outside the limited area, remains free from contact with the contact member and thus also from contact with the electrolyte. The substrate is passed along the contact member in a dragging manner while electrolyte is supplied to the contact member. In the area where the contact member is in contact with the substrate, a layer of metal is formed by plating. The person skilled in the art is quite familiar with brush-plating, as a result of which a detailed description may be omitted here. Reference is made to the international patent application WO 92/22685 A1 for an example of brush-plating, Fig. 1 of which shows an example of brush-plating.

According to the invention, a masking layer is applied to the substrate surface in this area beforehand by printing a masking layer in the respective area on the substrate by means of inkjet printing except for the plating part or on those parts of the substrate surface on which a layer is intended to be applied by plating. It is thus possible to apply a metal layer on the plating part of the substrate surface with great accuracy by plating during brush-plating.

The invention is not limited to the above-described embodiments but is defined by the following claims. The invention may be used for substrates of different types, such as lead frames, optionally punched and/or etched flat band, optionally laminated film/foil and/or semi-finished products for electronic components, such as for connectors, semiconductors, solar cells, LEDs and batteries.

Claims

1 . Method for applying a layer on a plating part of a substrate surface, comprising applying the layer on the plating part by plating, to which end the plating part is brought into contact with an electrolyte, wherein a first part of the part of the substrate surface situated outside the plating part is kept free from contact with the electrolyte, wherein a second part, which at least partly deviates from the first part, of the part of the substrate surface situated outside the plating part is masked during application of the layer due to a masking layer having been printed thereon by means of inkjet printing, with the plating part adjoining the second part.

2. Method according to Claim 1 , wherein the plating part does not adjoin the first part.

3. Method according to Claim 1 or 2, wherein the first part of the surface and the second part of the surface partly overlap.

4. Method according to Claim 1 , 2 or 3, wherein the size of the first part of the surface is greater than the size of the second part of the surface.

5. Method according to one of the preceding claims, wherein the substrate is panel-shaped or is at least made of panel-shaped material.

6. Method according to one of the preceding claims, wherein the plating part is situated on an, at least substantially, projecting part of the substrate.

7. Method according to Claim 6, wherein the projecting part has a cross section of which the masking layer is printed on a part of the periphery thereof and the layer is applied on another part of the periphery thereof by plating.

8. Method according to Claim 7, wherein the cross section has a rectangular shape or at least has four edges adjoining each other between neighbouring longitudinal sides, wherein the rectangular shape is determined four longitudinal sides of the projecting part, wherein the plating part extends over at least a part of a first longitudinal side, wherein a third longitudinal side is situated opposite the first longitudinal side and the masking layer is provided on the second longitudinal side which adjoins both the first longitudinal side and the third longitudinal side, and/or on the fourth longitudinal side which likewise adjoins both the first longitudinal side and the third longitudinal side.

9. Method according to Claim 8, wherein the plating part extends only over a part of the first longitudinal side and the masking layer is also provided on the first longitudinal side.

10. Method according to Claim 9, wherein the plating part is situated at a distance from the periphery of the first longitudinal side over its entire periphery.

1 1 . Method according to Claim 8, 9 or 10, wherein the masking layer is also provided on the third longitudinal side.

12. Method according to one of Claims 6 to 1 1 , wherein the projecting part, at a free end thereof, has an end side on which the masking layer is printed.

13. Method according to one of the preceding claims, wherein the plating part is a bent part of the substrate surface.

14. Method according to one of the preceding claims, wherein the second part is a bent part of the substrate surface.

15. Method according to one of the preceding claims, wherein the substrate is band-shaped.

16. Method according to Claims 1 to 14, wherein the substrate is strip- shaped.

17. Method according to one of the preceding claims, wherein the substrate is suspended from a band-shaped carrier during the application of the layer by plating.

18. Method according to one of the preceding claims, wherein the substrate is being transported during application of the layer.

19. Method according to one of the preceding claims, wherein the first part is at least partly masked by at least one masking body during application of the layer, to which end the at least one masking body is positioned against the first part before application of the layer and is moved away from the first part after application of the layer.

20. Method according to Claim 19, wherein the at least one masking body is also positioned against a part of the second part before application of the layer and is also moved away from that part of the second part after application of the layer.

21 . Method according to Claim 19 or 20, wherein the at least one masking body comprises at least two belts which, at a distance apart, mask edges of the substrate which are situated opposite each other.

22. Method according to Claim 19, 20 or 21 , wherein the at least one masking body comprises a belt which is closed.

23. Method according to Claim 19, 20 or 21 , wherein the at least one masking body comprises a belt which comprises openings, wherein the second part of the surface partly extends inside the openings during application of the layer.

24. Method according to one of Claims 18 and according to one of Claims 19 to 23, wherein the at least one masking body moves along with the substrate during transportation thereof.

25. Method according to one of Claims 19 to 24, wherein the substrate is completely immersed in the electrolyte.

26. Method according to one of Claims 1 to 18, wherein the plating part is immersed in the electrolyte and the first part is, at least partly, held above the electrolyte in order to apply the layer.

27. Method according to Claim 26, wherein the first part is held completely above the electrolyte.

28. Method according to Claim 26 or 27, wherein the second part is partly held above the electrolyte.

29. Method according to one of the preceding claims, wherein a cathode voltage is applied to the substrate via the first part in order to apply the layer.

30. Method according to Claim 26, 27 or 28 and according to Claim 29, wherein the cathode voltage is applied via a position above the electrolyte.

31 . Method according to one of Claims 1 to 24, wherein electrolyte is supplied to the plating part in order to apply the layer.

32. Method according to Claim 31 , wherein the electrolyte is supplied to the plating part via a contact member which is in contact with the plating part at the periphery thereof.

33. Method according to Claim 32, wherein the contact member rotates and partly extends into the electrolyte.

34. Method according to Claim 32, wherein the contact member is stationary, wherein the electrolyte is supplied to the stationary contact member.

35. Method according to one of the preceding claims, wherein the masking layer is removed from the surface after application of the layer.

36. Method according to one of the preceding claims, wherein the masking layer is printed on the second part of the substrate surface by means of inkjet printing before application of the layer on the plating part.

37. Method according to Claim 36, wherein the masking layer is printed on the second part of the substrate surface by means of a printhead whose orientation with respect to the substrate changes during printing.

38. Substrate on which a layer has been applied by plating by means of a method according to one of the preceding claims.