AU775221B2

AU775221B2 - Electro-plating apparatus and a method of electro-plating

Info

Publication number: AU775221B2
Application number: AU40804/01A
Authority: AU
Inventors: John Michael Lowe
Original assignee: TDAO Ltd
Current assignee: TDAO Ltd
Priority date: 2000-03-13
Filing date: 2001-03-13
Publication date: 2004-07-22
Anticipated expiration: 2021-03-13
Also published as: EP1266052A1; JP2003527489A; MXPA02008976A; KR20030007464A; CA2403116A1; WO2001068951A1; AU4080401A; RU2244767C2; CN1425080A; GB0005883D0; HK1053153A1; BR0109301A

Description

31/05 2004 15:35 FAX 61 3 92438333 GRIFFITH HACK 007 -1- ELECTRO-PLATING APPARATUS AND A METHOD OF ELEC TRO-PLATING The present invention related to electro-plating apparatus and a method of clectroplating.

In a conventional electro-plating process, the object to be plated is imaersed in a bath of electrolyte together with, but not touching, one or more pieces of the metal with which it is to be plated. Connections are made to a source of electrical current such that the item to be plated becomes the cathode and the pieces of metal become the anode.

When an electric current is supplied, ions flow towards the cathode and are reduced thereon to give a coating of the metal from which the anodes are made In another electro-plating process, described in International Patent Application No.

WO 99/52336, conductive tracks are provided on a printed circuit by i.se of a tool having an absorptive member carrying a plating solution.

According to the present invention, there is provided an electro-plating apparatus comprising a cathode connector for contact with a substrate onto whic it material is to be deposited, wherein the cathode connector has means to contact a plural ity of discrete regions extending substantially across the width of the substrate and mnrmal to the direction of movement of the substrate, when present, and not in the plane of the substrate.

0 *0 0 2 5 Preferably the cathode connector is elongate and adapted for movement relative to the substrate, the cathode connector having a main body lying along the loigitudinal axis of the cathode connector and at least one projection which extends away from the main body.

0000 0000 9900 eo 0 *e *eee *•ee COMS ID No: SBMI-00772100 Received by IP Australia: Time 15:43 Date 2004-05-31 31/05 2004 15:35 FAX 61 3 92438333 GRIFFITH BACK Z008 In this way, electrical contact is maintained with portons Of tile subst-ate Which would be otherwise electrically isolated fr'om the main body of the substrate.

The present invention may include any one or more of the following ]preferred features:- "the cathode connector comprises a comb-shaped element having aii elongate body and at least one tooth extending away from the main body section 'owards a location for a substrate on which material is to be deposited, to COT! tact in use a portion of the substrateat least one tooth is flexibly biased towards a location for a substra, e on which mnaterial is to be deposited.

"each tooth comprises an end portion inclined, relative to the remindler of the tooth, is in a direction towards a location of the substrate to provide flexible bias towards a location for a substrate on which material is to be deposited.

the cathode connector comprises a roller having at least one disk ex,,ending away ftrm the roller towards a location for a substrate on COMS ID No: SBMI-00772100 Received by IP Australia: Time 15:43 Date 2004-05-31 vvu U II~j~1 Mage 4or ~4 WV V1/D~IY~~ -age 4 ol14 WO 01/68951 PCT/GB01/01086 3 which material is to be deposited, to contact in use a portion of the substrate.

the cathode connector is formed of copper, or beryllium copper, or phosphor bronze, or stainless steel, or any other material with the required electrical and mechanical properties.

means to pass a substrate, onto which material is to be deposited, over the cathode the length of which extends a substantial part of, or all, the width of the substrate.

an electro-plating bath into which the substrate is immersed for deposition of material.

the cathode connector is located adjacent to the path of a substrate to contact, in use, the substrate before entering the bath.

the cathode connector is located adjacent to the path of a substrate to contact, in use, the substrate after leaving the bath.

cleaning means to remove electrolyte from the substrate downstream of the cathode connector.

cleaning means to remove electrolyte from the substrate upstream of the cathode connector.

at least one nozzle means to direct cleansing fluid towards the substrate.

electro-plating means to effect dry plating of material onto a substrate.

31/05 2004 15:35 FAX 61 3 92438333 GRIFFITH HACK 0009 -4a tool having an absorptive member to carry plating solution.

the electrode comprises a plurality of teeth or discs, one or more contact electrically with a separate region which is isolated from other regions oft ie substrate on the substrate.

the teeth or discs are adjustably spaced along the main portion.

According to the present invention there is also provided an electro-pl.iting method for 1 o depositing a material onto a substrate, the method comprising applying a cathode connector to contact with a plurality of discrete regions extending substantially across the width of the substrate and normal to the direction of movement of tile substrate and not in the plane of the substrate.

Preferably the method comprises moving the cathode connector relativ,., to the substrate, the cathode connector having a main body lying along the longitudinal axis of the cathode connector and at least one projection which extends away from the main body.

The method may include any one or more the following preferred features: passing a substrate, onto which material is to be deposited, over the cathode connector the length of which extends a substantial or part of, or all, the width of the substrate.

0000 0 im-mersing the substrate, onto which material is to be deposited into :m electro- 25 plating bath containing electrolyte.

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0 0 0 COMS ID No: SBMI-00772100 Received by IP Australia: Time 15:43 Date 2004-05-31 WO 01/68951 Page 6 of 24 WO 01/68951 __Pag_6of 24 WO 01/68951 PCT/GB01/01086 passing the substrate over the cathode connector located adjacent to the path of a substrate to contact the substrate before entering the bath.

passing the substrate over the cathode connector located adjacent to the path of a substrate to contact with the substrate after leaving the bath.

cleaning the substrate downstream of the cathode connector to remove electrolyte.

cleaning the substrate upstream of the cathode connector to remove electrolyte.

effecting dry plating of material onto a substrate.

Apparatus or methods of the present invention as described herein may provide the following advantages:effective electro-plating of isolated regions not connected with one another) of the substrate is ensured.

effective electro-plating is achieved even for highly-flexible substrates.

effective electro-plating is achieved even for substrates having very roughened surface.

The present invention also provides a computer program product directly loadable into the internal memory of digital computer, comprising software WO 01/68951 Page 7of 24 WO 01168951 Page 7 of 24 WO 01/68951 PCT/GB01/01086 6 code portions for performing the steps of a method of the present invention when said product is run on a computer.

The invention is applicable to electro-plating processes including, but not limited to, those as described hereinabove.

In order that the present invention may more readily be understood, a description is now given, by way of example only, reference being made to the accompanying drawings, in which:- Figure 1 is a block schematic drawing of electro-plating apparatus embodying the present invention; Figure 2 is a schematic drawing of an alternative apparatus; Figure 3A is a detailed view of part of a conventional apparatus; Figure 3B is a detailed view of part of the apparatus of Figure 2; Figure 4 is a schematic drawing of a further embodiment of apparatus; Figure 5 is a schematic drawing of a further embodiment of apparatus.

Electro-plating apparatus 1 as shown in Figure 1 comprises an electroplating bath 2 containing electrolyte 3, an anode configuration immersed in electrolyte 3 and comprising a planar anode 4 and an arcuate solid anode In use, a continuous web of flexible substrate 6 (onto both sides of which material is to be deposited) is passed along a transport system 7 in a direction shown by arrow A. Transport system 7 comprises a set of rollers 8,9 of which rollers 8 are generally cylindrical, driving rollers while rollers 9 are cathode connector and have a number of circumferential projections 10 which ensure electrical contact (in spite of the transport speed, substrate flexibility or roughness of substrate 6) with unconnected or discrete regions on substrate 6.

Figure 2 shows another electro-plating apparatus 20 having a cathode connector configuration 21 with four comb electrodes 22 each having a WO 01/56951 Page Sot 24 WO 01/6895 1 P.age 8 of 24 WO 01/68951 PCT/GBO1/01086 7 main portion 23 with a plurality of teeth 24 each of which has end inclined in the direction of the movement of the substrate.

In each embodiment, the teeth 24 may be equi-spaced along the comb main portion 23 or they may be spaced to fit with the required region spacing of the substrate. The positioning of the teeth along the main portion 23 may be adjustable to accommodate either option.

Figure 3A show the problem associated with disconnected areas in a conventional plating bath. The inner conducting area 50 is electrically isolated from the outer conducting area 51 by the non-conducting area 52 and, therefore, the inner area 50 is not connected electrically to the negative terminal 53 of the current source.

Figure 3B shows how cathode connector 60 connects discrete areas to the negative potential and shows the use of a cathode connector 60 whereby the substrate 61 passes over the cathode connector 60 just prior to entering the electrolyte 62. All conducting areas on the substrate 61 are contacted by one or more fingers 63 of the cathode connector 60 such that contact is maintained until at least 50% the length, in the direction of substrate travel, has passed into the electrolyte 62. The gap between the cathode connector and the electrolyte 62 causes a portion of the conducting parts of the substrate not to be plated because of the loss of contact. These portions are plated at the time of exit from the electrolyte 62 when the already plated area make contact with a further cathode connector situated just above the point at which the substrate exits the electrolyte 62. Conducting area 64 on substrate 61 is surrounded by non-conducting areas 65 but fingers 63 of cathode 60 still make contact to ensure electro-plating happens.

31/05 2004 15:35 FAX 61 3 92438333 GRIFFITH HACK 0010 -8- Figure 4 shows an electro-plating apparatus 30 for plating a rigid subt trate 31 which hence cannot be immersed in an electrolyte bath in the manner of Figures 1 and 2.

Apparatus 30 comprises a hollow anode 32 through the centre of which electrolyte 33 is directed onto a portion of substrate 31 moving in direction B and then removed along side channels 34. Cathode connectors 35 are in the form of comb maia portions 36 with teeth 37 to ensure that unconnected regions of substrate 31 are electrically connected to cathode connectors 35 before and after impingement of electrolyte 33 lo ensure that there is adequate deposition of material onto all required parts of substrate 31.

Two cleaners 38 with nozzles 39 are provided to direct de-ionised wat,'r onto the substrate 30 before and after contact with cathodes In a variant, roller 8 or main comb portion 23 may have a brush instead of projections disc or teeth 24 to contact the discrete or unconnected regions on substrate 6.

is Figure 5 shows a variant of the apparatus of Figure 4 but wherein both ;ides of substrate 31 are plated.

For the purposes of this specification it will be clearly understood that the word "comprising" means "including but not limited to", and that the word ":omprises" has a corresponding meaning.

Further, any reference herein to prior art is not intended to imply that such prior art forms or formed a part of the common general knowledge.

gee.

o*oo **oo *oo* o*eo* COMS ID No: SBMI-00772100 Received by IP Australia: Time 15:43 Date 2004-05-31

Claims

2. An apparatus as claimed in claim 1, wherein said cathode connector is elongate and adapted for movement relative to said substrate, the cathode connector having a main body lying along the longitudinal axis of the cathode connector and at least one projection which extends away front the main body.
3. An apparatus as claimed in either claim 1 Or 2, wherein the cathode connector comprises a comb-shaped element having an elongate body and at lea:tt one tooth extending away frm the main body section towards a location fir a substrate on which material is to be deposited, to contact in use a portion of the substrate.
4. An apparatus as claimed in claim 3 wherein the at least one tooth is flexibly biased towards a location for a substrate on which material is to be deposited, An apparatus as claimed in either claim 3 or 4 wherein said at least one tooth comprises an end portion inclined, relative to the remainder of the tooth, in a direction towards a location of the substrate to provide flexible bias towards a location of a substrate on which material is to be deposited.
6. An apparatus as claimed in either claim I or 2 wherein the cathode .connector comprises a roller having at least one disk extending away from the rol er towards a location for a substrate on which material is to be deposited, to contact in use a portion of thc stubstrate.
7. An apparatus as claimed in any one of the preceding claims wherein the c-athode connector is formed of copper or berylliiurn copper, or phosphor bronze. or stainless SBMI-00772100 Received by IP Australia: Time 15:43 Date (Y4.4-d) 2004-05-31 31/05 2004 15:36 FAX 61 3 92438333 GRIFFITH HACK @012 steel.
8. An apparatus as claimed in any one of the preceding claims comprising means to pass a substrate, onto which material is to be deposited, over the catho, le connector the length of which extends a substantial part of, or all, the width of the sub)strate. 1
9. An apparatus as claimed in any one of the preceding claims comprising an electro- plating bath into which the substrate is immersed for deposition ofmat.'rial.
10. An apparatus as claimed in claim 9 wherein the cathode connector is located adjacent to the path of a substrate to contact, in use, the substrate beforL entering the bath.
11. An apparatus as claimed in either claim 9 or 10 wherein the cathode connector is located adjacent to the path of a substrate to contact, in use, the substrato after leaving the bath.
12. An apparatus as claimed in any one of claims 9 to 11 comprising cl. :aning means to remove electrolyte from the substrate downstream of the cathode connector.
13. An apparatus as claimed in any one of claims 9 to 12 comprising claning means to S-remove electrolyte from the substrate upstream of the cathode connectoi
14. An apparatus as claimed in any one of claims 9 to 13 comprising at 'east one nozzle 0 25 to direct cleansing fluid towards the substrate. 0%.0
15. An apparatus as claimed in any one of claims 1 to 7 comprising eleero-plating means to effect dry plating of material onto a substrate.
16. An apparatus as claimed in claim 15 comprising a tool having a absorptive member to carry plating solution. A 0
17. An apparatus as claimed in any one of the preceding claims wherein .he cathode 00 *0* 0 *~o *•o COMS ID No: SBMI-00772100 Received by IP Australia: Time 15:43 Date 2004-05-31 31/05 2004 15:36 FAX 61 3 92438333 GIFT AKll1 GRIFFITH HACK Q013 -Il- connector comprises a plurality of teeth or discs, one or more to cont ti electrically with a separate region which is isolated from oilier regions of the subs: rate on the substrate.
18. An apparatus as claimed in claim 17 wherein teeth or discs are adjastably spaced along the main portion of the cathode connector.
19. An electro-plating method for depositing a material onto a substratk, the method comprising applying a cathode connector to contact with a plurality of liscrete regions extending substantially across the width of the substrate and normal to 'he direction of movement of the substrate and not in the plane of the substrate. A method as claimed in claim 19 comprising moving said cathode -;-onnector relative to said substrate, the cathode connector having a main body lyli tg along the longitudinal axis of the cathode connector and at least one projection wi] dicl extends away from the main body.
21. A mnethod as claimed in claim 19 wherein the cathode connector comprises a comb- shaped element having an elongate body and at least one finger extending away from the main body section towards a location for a substrate on which mater- al is to be deposited, to contact in use a portion of the substrate.
22. A method as claimed in claim 21 wherein said connector includes al least one tooth flexibly biased towards a location for a substrate on which material is to be deposited.
23. A mcthod as claimed in either claim 21 or 22 wherein said at least oi ie tooth comprises an end portion inclined, relative to the remaainder of the tooth, in a direction towards a location of the substrate to provide flexible bias towards a loca ion for a substrate on which material is to be deposited.
24. A method as claimed in claim 20 wherein the cathode connector comprises a roller having at least one disk extending away from the roller towards a locationl for a substrate on which material is to be deposited, to contact in use a portion the COMS ID No: SBMI-00772100 Received by IP Australia: Time 15:43 Date 2004-05-31 31/05 2004 15:37 FAX 61 3 92438333 GRIFFITH BACK 0014 -12- substrate- A method as claimed in any one of claims 19 to 24 wherein the cithode is formed of copper or beryllium copper, or phosphor bronze, or stainlcss steel.
26. A method as claimed in any one of claims 19 to 25 comprising passing a substrate, onto which material is to be deposited, over the cathode connector the length of which extends a substantial or part of, or all, the width of the substrate.
27. A method as claimed in any one of claims 19 to 26 comprising immersing the substrate, onto which material is to be deposited, into an electro-plating bath containing electrolyte.
28. A method as claimed in claim 27 comprising passing the substrate over the cathode connector located adjacent to the path of a substrate to contact the substrate before entering the bath.
29. A method as claimed in either claim 27 or 28 comprising passing ihe substrate over the cathode connector located adjacent to the path of a substrate to contact with the substrate after leaving the bath.
30. A method as claimed in any one of claims 27 to 29 comprising cleaning the oo.. substrate downstream of the cathode connector to remove electrolyte. .0 0 0 0 0o 0.'4 25 3 1. A method as claimed in any one of claims 27 to 30 comprising cleaning the substrate upstream of the cathode to remove electrolyte. 0S0. *00*0
32. A method as claimed in any one of claims 27 to 31 comprising dirccting a 00 cleansing fluid against the substrate.
33. A method as claimed in any one of claims 19 to 26 comprising efft-cting dry plating @000 o0 o of material onto a substrate. 0 0 0 COMS ID No: SBMI-00772100 Received by IP Australia: Time 15:43 Date 2004-05-31 31/05 2004 15:37 FAX 61 3 92438333 GRIFFITH HACK -13-
34. A method as claimed in claim 33 comprising a tool having a absorptive member to carry plating solution. A method as claimed in any one of claims 19 to 34 wherein the c ithode connector comprises a plurality of teeth or discs, one or more to contact electric;lly with a separate region which is isolated from other rcgions of the substrate on the substrate.
36. A method as claimed in any one of claims 19 to 35 comprising aci justing the spacing of the teeth or discs along the main portion of the cathode.
37. A computer program product directly loadable into the internal memory of a digital computer, comprising software code portions for performing the steps of a method as claimed in any one of claims 19 to 36 when said product is run on a ccmputer.
38. Electronic distribution of a computer program as claimed in claim 37.
39. An electro-plating apparatus substantially as hereinbefore describ, with reference to figure 1 or to figures 2 and 3B or to figure 4 or to figure 5 of the accompanying drawings. An electro-plating method substantially as hereinbefore described with reference to figure 1 or to figures 2 and 3B or to figure 4 or to figure 5 of the accoripanying 0*o• drawings. S 0 25 Dated this 31st day of May 2004 TDAO LIMITED S**S. t o o By their Patent Attorneys GRIFFITH HACK Fellows Institute of Patent and S 30 Trade Mark Attorneys of Australia S.* 0 0 S 0 #0^0 4 @9 O 0 S 0 COMS ID No: SBMI-00772100 Received by IP Australia: Time 15:43 Date 2004-05-31