US5284554A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrochemical micromachining tool and process for through-mask patterning of thin metallic films supported by non-conducting or poorly conducting surfaces
Assignee: International Business Machines Corp
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Filing: 1992-01-09
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Granted: 1994-02-08
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Expires: 2012-01-09
Abstract
Abstract The present invention describes a high speed, high precision electrochemical micromachining tool, chemical solution and method for the one sided through-mask micropatterning of conducting foils and films supported by insulating material. The tool of the present invention can include either a movable plate means allowing for the movement of the workpiece to and fro above the cathode assembly, or a movable cathode assembly means allowing for the movement of said cathode assembly to and fro beneath the workpiece. Said cathode assembly also consists of a nozzle assembly from which the electrolytic solution emerges as electrolytic shower and impinges upon the workpiece. Methods to resolve the problems related to the loss of electrical contact during the electrochemical micromachining process are also described.
Inventors
- 👤 Madhav Datta
- 👤 Lubomyr T. Romankiw
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 07:08
CPC Classifications
C; C25; C25F; C25F3/00; C25F3/02; C25F3/14; H; H05; H05K; H05K3/00; H05K3/02; H05K3/06; H05K3/07
Claims Analysis
Total Claims: 33
Claim 1
Independent Claim
140 words
A tool for electrochemical micromachining of a sample comprising: container means for receiving and temporarily retaining an electrolytic solution from a supply source for said solution; a cathode assembly positionable within said container means, said cathode assembly comprising receptacle means for supplying the electrolytic solution from said container means, and nozzle means for receiving said electrolytic solution from said receptacle means and directing said electrolytic solution against said sample; plate means for holding the sample facing towards said cathode assembly at a variable distance therefrom, said sample having a photoresist mask deposited on a portion of one side of the surface of said sample, lateral movement means for providing relative lateral movement between said sample and said cathode assembly; and power supply means having a negative terminal connected to said cathode assembly and a positive terminal connected to said sample.
Claim 2
Dependent Claim
140 words
A tool for electrochemical micromachining of a sample comprising: container means for receiving and temporarily retaining an electrolytic solution from a supply source for said solution; a cathode assembly positionable within said container means, said cathode assembly comprising receptacle means for supplying the electrolytic solution from said container means, and nozzle means for receiving said electrolytic solution from said receptacle means and directing said electrolytic solution against said sample; plate means for holding the sample facing towards said cathode assembly at a variable distance therefrom, said sample having a photoresist mask deposited on a portion of one side of the surface of said sample, lateral movement means for providing relative lateral movement between said sample and said cathode assembly; and power supply means having a negative terminal connected to said cathode assembly and a positive terminal connected to said sample.
Claim 3
Dependent Claim
30 words
A tool according to claim 1, wherein said lateral movement means provides lateral movement to said plate means to provide lateral displacement of the sample relative to said cathode assembly.
Claim 4
Dependent Claim
30 words
A tool according to claim 1, wherein said lateral movement means provides lateral movement to said cathode assembly to provide lateral displacement of said cathode assembly relative to the sample.
Claim 5
Dependent Claim
30 words
A tool according to claim 1, wherein an enclosure encompasses said cathode assembly and a nozzle plate mounting said enclosure means is arranged thereon so as to form a cover.
Claim 6
Dependent Claim
33 words
A tool according to claim 4, wherein said nozzle plate has an array of circular holes comprising said nozzle means from which the electrolytic solution impinges against the sample as an electrolytic shower.
Claim 7
Dependent Claim
25 words
A tool according to claim 1, wherein said container means is operatively connected to a pump, filter and said receptacle means of said cathode assembly.
Claim 8
Independent Claim
126 words
A method for electrochemical micromachining of a sample comprising the steps of: (a) mounting a sample on a plate means facing towards a cathode assembly; (b) making the sample and said cathode assembly respectively an anode and cathode in an electrical circuit; (c) adjusting the interelectrode spacing between the sample and said cathode assembly to a distance effective to keep the anode and cathode from interfering with one another while also maintaining a charge therebetween; (d) providing relative lateral movement between said sample and said cathode assembly; (e) continuously conducting an electric current through the electrical circuit; and (f) continuously circulating an electrolytic solution through said cathode assembly so that the electrolytic solution impinges against the sample as an electrolytic shower to effectively etch the sample.
Claim 9
Independent Claim
126 words
A method for electrochemical micromachining of a sample comprising the steps of: (a) mounting a sample on a plate means facing towards a cathode assembly; (b) making the sample and said cathode assembly respectively an anode and cathode in an electrical circuit; (c) adjusting the interelectrode spacing between the sample and said cathode assembly to a distance effective to keep the anode and cathode from interfering with one another while also maintaining a charge therebetween; (d) providing relative lateral movement between said sample and said cathode assembly; (e) continuously conducting an electric current through the electrical circuit; and (f) continuously circulating an electrolytic solution through said cathode assembly so that the electrolytic solution impinges against the sample as an electrolytic shower to effectively etch the sample.
Claim 10
Dependent Claim
15 words
A method according to claim 7, wherein said electrolytic solution comprises a neutral salt solution.
Claim 11
Dependent Claim
16 words
A method according to claim 8, wherein said neutral salt solution essentially consists of sodium nitrate.
Claim 12
Dependent Claim
16 words
A method according to claim 8, wherein said neutral salt solution essentially consists of sodium chloride.
Claim 13
Dependent Claim
14 words
A method according to claim 7, wherein said electrolytic solution includes a non-foaming surfactant.
Claim 14
Dependent Claim
19 words
A method according to claim 11, wherein said electrolytic solution is comprised of sodium nitrate and 100 ppm surfactant.
Claim 15
Dependent Claim
19 words
A method according to claim 11, wherein said electrolytic solution is comprised of sodium chloride and 100 ppm surfactant.
Claim 16
Dependent Claim
19 words
A method according to claim 7, wherein the cell voltage is between about 5 volts and about 15 volts.
Claim 17
Dependent Claim
19 words
A method according to claim 7, wherein the cell voltage is between about 9 volts and about 12 volts.
Claim 18
Dependent Claim
23 words
A method according to claim 7, wherein said interelectrode spacing is at a distance of from about 1 mm to about 3 mm.
Claim 19
Dependent Claim
14 words
A method according to claim 16, wherein said interelectrode spacing is about 1.5 mm.
Claim 20
Dependent Claim
22 words
A method according to claim 7, wherein the electrolytic solution impinges against the sample at a flow rate of about 1 gpm.
Claim 21
Dependent Claim
28 words
A method according to claim 7, wherein said plate means is laterally movable to displace the sample at a speed of about 0.2 cm/s to about 0.6 cm/s.
Claim 22
Dependent Claim
27 words
A method according to claim 7, wherein said plate means is laterally movable to displace the sample at a speed of 0.4 cm/s over said cathode assembly.
Claim 23
Dependent Claim
28 words
A method according to claim 7, wherein said cathode assembly is laterally movable to displace the sample at a speed of about 0.2 cm/s to about 0.6 cm/s.
Claim 24
Dependent Claim
25 words
A method according to claim 7, wherein said cathode assembly is laterally movable to displace the cathode assembly at a speed of about 0.4 cm/s.
Claim 25
Dependent Claim
25 words
A method according to claim 7, which comprises the step of initially masking a region of a maximum opening in the sample before step (a).
Claim 26
Dependent Claim
18 words
A method according to claim 23, wherein said region of maximum opening is masked with a plating tape.
Claim 27
Dependent Claim
27 words
A method according to claim 7 which comprises the step of introducing dummy photoresist artwork into regions of wide openings in the sample prior to step (a).
Claim 28
Dependent Claim
23 words
A method according to claim 25, wherein said dummy photoresist artwork matches the undercutting of said dummy photoresist artwork from opposite sides thereof.
Claim 29
Dependent Claim
27 words
A method according to claim 23, which comprises the step of introducing dummy photoresist artwork into regions of wide openings in the sample prior to step (a).
Claim 30
Dependent Claim
23 words
A method according to claim 27, wherein said dummy photoresist artwork matches the undercutting of said dummy photoresist artwork from opposite sides thereof.
Claim 31
Dependent Claim
21 words
The method according to claim 7, wherein the sample is a thin metallic film supported by non-conducting or poorly conducting surfaces.
Claim 32
Dependent Claim
15 words
The method according to claim 29, wherein the thin metallic film is a slider suspension.
Claim 33
Dependent Claim
15 words
The method according to claim 30, wherein said slider suspension is a integrated slider suspension.
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1997-02-07 | 1997-08-09 | 1998-02-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-02-07 | 2001-08-09 | 2002-02-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-02-07 | 2005-08-09 | 2006-02-08 | $7700.00 | Window Closed / Lapsed |