US5401909A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Printed circuit board with locally enhanced wiring density
Assignee: International Business Machines Corp
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Filing: 1993-11-17
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Granted: 1995-03-28
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Expires: 2013-11-17
Abstract
Abstract A printed circuit board and a method for making same is disclosed whereby a very high wiring density is provided in those regions of the printed circuit board in which external components (e.g., semiconductor chips) are to be attached directly. An automated registration routine permits very precise registration and positioning in those regions.
Inventors
- 👤 Hans Arnold
- 👤 Peter Lueck
- 👤 Guenther Mohr
- 👤 Theis ZurNieden
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 13:44
CPC Classifications
H; H10; H10W; H10W70/00; H10W70/60; H10W70/611; H05; H05K; H05K1/00; H05K1/02; H05K1/0266; H05K1/0269; H05K1/11; H05K1/111; H05K1/112; H05K1/113; H05K3/00; H05K3/46; H05K3/4602; H05K3/4688; H05K3/4694; H10W70/01; H10W70/05; H10W70/67; H10W70/68; H10W70/685; H05K2201/00; H05K2201/03; H05K2201/0332; H05K2201/0335; H05K2201/0352; H05K2201/09; H05K2201/09209; H05K2201/095; H05K2201/09509; H05K2201/09818; H05K2201/09918; H05K2201/09972; H05K2201/10; H05K2201/10613; H05K2201/10621; H05K2201/10674; H05K2203/00; H05K2203/05; H05K2203/0502; H05K2203/054; H05K2203/0562; H05K2203/0574; H05K2203/06; H05K2203/068; H05K2203/10; H05K2203/107; H05K3/0011; H05K3/0017; H05K3/0073; H05K3/0082; H05K3/02; H05K3/06; H05K3/061; H05K3/064; H10W72/00; H10W72/071; H10W72/072; H10W72/07251; H10W72/20; H10W90/00; H10W90/701; H10W90/721; H10W90/724
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
173 words
A printed circuit board comprising: a dielectric material having at least one inner electrically conductive layer; electrically conducting lines located on an external surface of said dielectric material in a first region of a first width and having a first wiring density; a layer of a second dielectric material substantially covering a localized sub-region of said first region of said electrically conducting lines and including a plurality of holes therein, selected ones of said holes being located relative to respective ones of said conducting lines in said sub-region, said localized sub-region having a second width less than said first width of said first region, said layer of second dielectric material not including an internal layer of conductive wiring therein; and a plurality of electrical conductors located only on said layer of second dielectric material and electrically coupled to said respective ones of said conducting lines in said localized sub-region through said holes, said electrical conductors being of a second wiring density substantially greater than said first wiring density of said electrically conducting lines.
Claim 2
Dependent Claim
173 words
A printed circuit board comprising: a dielectric material having at least one inner electrically conductive layer; electrically conducting lines located on an external surface of said dielectric material in a first region of a first width and having a first wiring density; a layer of a second dielectric material substantially covering a localized sub-region of said first region of said electrically conducting lines and including a plurality of holes therein, selected ones of said holes being located relative to respective ones of said conducting lines in said sub-region, said localized sub-region having a second width less than said first width of said first region, said layer of second dielectric material not including an internal layer of conductive wiring therein; and a plurality of electrical conductors located only on said layer of second dielectric material and electrically coupled to said respective ones of said conducting lines in said localized sub-region through said holes, said electrical conductors being of a second wiring density substantially greater than said first wiring density of said electrically conducting lines.
Claim 3
Dependent Claim
23 words
The printed circuit board according to claim 1 wherein said second wiring density is about four times that of said first wiring density.
Claim 4
Dependent Claim
44 words
The printed circuit board according to claim 1 wherein said first wiring density is from about 5 cm/cm 2 to about 10 cm/cm 2 , and said second wiring density is from about 20 cm/cm 2 per layer to about 40 cm/cm 2 .
Claim 5
Dependent Claim
24 words
The printed circuit board according to claim 1 wherein said electrical conductors located on said layer of second dielectric material are comprised of copper.
Claim 6
Dependent Claim
25 words
The printed circuit board according to claim 1 wherein said layer of second dielectric material possesses a dielectric constant from about 2.5 to about 3.5.
Claim 7
Dependent Claim
17 words
The printed circuit board according to claim 5 wherein said second dielectric material is comprised of polyimide.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1998-03-27 | 1998-09-26 | 1999-03-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-03-27 | 2002-09-26 | 2003-03-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-03-27 | 2006-09-26 | 2007-03-28 | $7700.00 | Window Closed / Lapsed |