US4963512A
Expired / Lapsed
US
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Method for forming conductor layers and method for fabricating multilayer substrates
Assignee: Hitachi Ltd
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Filing: 1988-12-08
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Granted: 1990-10-16
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Expires: 2008-12-08
Abstract
Abstract A method for forming conductor layers of substrates for mounting LSIs and the like and a fabrication method of multilayer substrates are disclosed. These methods comprise steps of forming a metal underlayer having a shape similar to that of a conductor pattern on the substrate, forming an insulation layer over portions of the substrate which are not covered by the metal underlayer, and disposing a plating layer on the metal underlayer by carrying out electroless plating while using the insulation layer as the resist and thereby forming conductors. As compared with a conventional conductor layer forming method, the number of fabrication steps is reduced. And the elimination of the surface grinding step facilitates the fabrication.
Inventors
- 👤 Shoichi Iwanaga
- 👤 Akio Fujiwara
- 👤 Takayoshi Sowa
- 👤 Hitoshi Yokono
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 00:08
CPC Classifications
H; H05; H05K; H05K3/00; H05K3/46; H05K3/4644; H05K3/465; H10; H10W; H10W70/00; H10W70/01; H10W70/05; H05K2201/00; H05K2201/01; H05K2201/0137; H05K2201/0154; H05K2203/00; H05K2203/07; H05K2203/0703; H05K2203/072; H05K2203/0733; H05K3/0011; H05K3/0017; H05K3/0041; H05K3/38; H05K3/388; H05K3/4661
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
177 words
A method of forming a conductor layer on a substrate comprising, in sequence, the steps of: previously forming a metal underlayer on a surface of a substrate designated to have a conductor formed thereon, said metal underlayer comprising an upper layer of chromium and said metal underlayer being patterned to have a pattern slightly larger than and similar to a desired conductor pattern; forming a polyimide insulation layer over said substrate surface, said polyimide insulation layer being patterned by dry etching to form a groove and to expose a portion of said metal underlayer on which said desired conductor pattern is to be formed; removing the upper layer of chromium with wet etching after formation of the groove to expose a metal layer of the underlayer active to electroless plating; and disposing a plating layer in the groove and on the exposed portion of said metal underlayer by carrying out electroless plating while applying said polyimide insulation layer as a mask and thereby forming a conductor layer with a high aspect ratio ranging from 0.6 to 1.5.
Claim 2
Independent Claim
177 words
A method of forming a conductor layer on a substrate comprising, in sequence, the steps of: previously forming a metal underlayer on a surface of a substrate designated to have a conductor formed thereon, said metal underlayer comprising an upper layer of chromium and said metal underlayer being patterned to have a pattern slightly larger than and similar to a desired conductor pattern; forming a polyimide insulation layer over said substrate surface, said polyimide insulation layer being patterned by dry etching to form a groove and to expose a portion of said metal underlayer on which said desired conductor pattern is to be formed; removing the upper layer of chromium with wet etching after formation of the groove to expose a metal layer of the underlayer active to electroless plating; and disposing a plating layer in the groove and on the exposed portion of said metal underlayer by carrying out electroless plating while applying said polyimide insulation layer as a mask and thereby forming a conductor layer with a high aspect ratio ranging from 0.6 to 1.5.
Claim 3
Dependent Claim
24 words
A method for forming a conductor layer according to claim 1, wherein said insulation layer is formed on the periphery of said metal underlayer.
Claim 4
Dependent Claim
30 words
A method for forming a conductor layer according to claim 14, wherein said metal underlayer comprises a chromium layer, a copper layer and a chromium layer in a sandwich structure.
Claim 5
Dependent Claim
34 words
A method for forming a conductor layer according to claim 1, wherein a photoresist layer formed by spin-coating an organosilicon polymer material and heating it is used as a mask for said dry etching.
Claim 6
Dependent Claim
33 words
A method for forming a conductor layer according to claim 1, wherein an SiO 2 layer and a photoresist layer on said insulation layer are applied as a mask for said dry etching.
Claim 7
Dependent Claim
25 words
A fabrication method of multilayer conductor patterns according to claim 5, wherein said first insulation layer is formed on the periphery of said metal underlayer.
Claim 8
Dependent Claim
257 words
A fabrication method of multilayered conductor patterns comprising the steps of: (a) forming a metal underlayer on a surface of a substrate destined to have a conductor formed thereon, said metal underlayer comprising an upper layer of chromium and said metal underlayer being patterned to form a desired conductor pattern, with a slightly larger dimension than said conductor pattern; (b) forming a first polyimide insulation layer over portions of said substrate and said metal underlayer; (c) providing a conductor pattern in said first polyimide insulation layer by dry etching to from a groove and to expose a portion of said metal underlayer; (d) removing the upper layer of chromium with wet etching after formation of the groove to expose a metal layer of the underlayer active to electroless plating; (e) disposing a plating layer in the groove and on the exposed portion of the metal underlayer by conducting electroless plating while applying the first polyimide insulation layer as a mask and thereby forming a patterned conductor having a high aspect ratio ranging from 0.6 to 1.5; (f) forming a chromium layer on said patterned conductor; (g) forming a second polyimide insulation layer on said patterned conductor to form a through-hole on said conductor; (h) removing the chromium layer from the patterned conductor by wet etching; (i) filling a plating layer in said through-hole by carrying out electroless plating using said second polyimide insulation layer as a mask; and (j) forming multilayered conductor patterns comprising conductors and insulation layers alternately laminated by repeating said steps (a) to (j).
Claim 9
Dependent Claim
257 words
A fabrication method of multilayered conductor patterns comprising the steps of: (a) forming a metal underlayer on a surface of a substrate destined to have a conductor formed thereon, said metal underlayer comprising an upper layer of chromium and said metal underlayer being patterned to form a desired conductor pattern, with a slightly larger dimension than said conductor pattern; (b) forming a first polyimide insulation layer over portions of said substrate and said metal underlayer; (c) providing a conductor pattern in said first polyimide insulation layer by dry etching to from a groove and to expose a portion of said metal underlayer; (d) removing the upper layer of chromium with wet etching after formation of the groove to expose a metal layer of the underlayer active to electroless plating; (e) disposing a plating layer in the groove and on the exposed portion of the metal underlayer by conducting electroless plating while applying the first polyimide insulation layer as a mask and thereby forming a patterned conductor having a high aspect ratio ranging from 0.6 to 1.5; (f) forming a chromium layer on said patterned conductor; (g) forming a second polyimide insulation layer on said patterned conductor to form a through-hole on said conductor; (h) removing the chromium layer from the patterned conductor by wet etching; (i) filling a plating layer in said through-hole by carrying out electroless plating using said second polyimide insulation layer as a mask; and (j) forming multilayered conductor patterns comprising conductors and insulation layers alternately laminated by repeating said steps (a) to (j).
Claim 10
Dependent Claim
26 words
A fabrication method of multilayer conductor patterns according to claim 7, wherein said metal underlayer comprises a chromium layer, a copper layer and a chromium layer.
Claim 11
Dependent Claim
35 words
A fabrication method of multilayer conductor patterns according to claim 7, wherein a photoresist layer formed by spin-coating an organosilicon polymer material and heating it is applied as a resist mask for said dry etching.
Claim 12
Dependent Claim
34 words
A fabrication method of multilayer conductor patterns according to claim 7, wherein an SiO 2 layer and a photoresist layer on said first insulation layer are applied as a mask for said dry etching.
References Cited (Backward Citations)
US3935635A
Cited
US3962004A
Cited
US3993515A
Cited
US4122215A
Cited
US4184909A
Cited
US4349609A
Cited
US4339305A
Cited
US4493855A
Cited
US4670967A
Cited
US4560436A
Cited
US4692349A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-10-15 | 1994-04-16 | 1994-10-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-10-15 | 1998-04-16 | 1998-10-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-10-15 | 2002-04-16 | 2002-10-16 | $7700.00 | Window Closed / Lapsed |