US5142775A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Bondable via
Assignee: International Business Machines Corp
•
Filing: 1990-10-30
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Granted: 1992-09-01
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Expires: 2010-10-30
Abstract
Abstract A method is disclosed for providing less critical alignment of vias and through holes and lower bonding stresses in the manufacture of high density circuit boards. In the invention, a via is drilled through a land which is in a plane separate from that of the signal plane.
Inventors
- 👤 John P. Wiley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 09:57
CPC Classifications
H; H05; H05K; H05K3/00; H05K3/46; H05K3/4611; H05K3/4614; H05K3/462; H05K3/44; H05K3/445; H05K1/00; H05K1/02; H05K1/0272; H05K2201/00; H05K2201/01; H05K2201/0137; H05K2201/015; H05K2201/09; H05K2201/09209; H05K2201/09372; H05K2201/09436; H05K2201/095; H05K2201/09536; H05K2201/096; H05K2203/00; H05K2203/13; H05K2203/1377; H05K2203/1383; H05K2203/1394; H05K3/0094; H05K3/40; H05K3/42; H05K3/429; H05K3/4644; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49117; Y10T29/49124; Y10T29/49126; Y10T29/49155; Y10T29/49165
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
176 words
A method of forming a multilayer printed circuit board comprising the steps of: a. circuitizing a first dielectric to form a circuitization plane having circuitization leads and first pads thereon; b. encapsulating the circuitization plane and the pads thereon with a second dielectric layer to form a relaminated core; c. drilling through the second dielectric layer, a pad on the first circuitization plane, and the first dielectric to form a via or through hole; d. depositing Cu in the via or through hole and on the second dielectric layer in proximity to the said via or through hole to form a plated via or through hole and a second pad, thereby forming a multilayer, relaminated core having a circuitization plane with circuitization leads and first pads and a bonding plane with a second pad, said second pad being separated from a corresponding first pad by the second layer of dielectric; and e. bonding said multilayer, relaminated core to another multilayer, relaminated core at facing pads thereon to form a stacked via joined at a bonding pad.
Claim 2
Independent Claim
176 words
A method of forming a multilayer printed circuit board comprising the steps of: a. circuitizing a first dielectric to form a circuitization plane having circuitization leads and first pads thereon; b. encapsulating the circuitization plane and the pads thereon with a second dielectric layer to form a relaminated core; c. drilling through the second dielectric layer, a pad on the first circuitization plane, and the first dielectric to form a via or through hole; d. depositing Cu in the via or through hole and on the second dielectric layer in proximity to the said via or through hole to form a plated via or through hole and a second pad, thereby forming a multilayer, relaminated core having a circuitization plane with circuitization leads and first pads and a bonding plane with a second pad, said second pad being separated from a corresponding first pad by the second layer of dielectric; and e. bonding said multilayer, relaminated core to another multilayer, relaminated core at facing pads thereon to form a stacked via joined at a bonding pad.
Claim 3
Dependent Claim
17 words
The method recited in claim 1, wherein the step of providing pads comprises providing centrally apertured pads.
Claim 4
Dependent Claim
19 words
The method recited in claim 1, wherein the step of encapsulating comprises encapsulating with a high performance dielectric material.
Claim 5
Dependent Claim
29 words
The method recited in claim 1, wherein the step of encapsulating comprises encapsulating with a high performance dielectric material selected from the group consisting of epoxies, fluoropolymers and cyanates.
Claim 6
Dependent Claim
16 words
The method recited in claim 1 wherein the step of providing pads comprises providing unapertured pads.
Claim 7
Dependent Claim
16 words
The method recited in claim 1 wherein the step of drilling comprises drilling by laser beam.
Claim 8
Dependent Claim
14 words
The method recited in claim 1, wherein the step of drilling comprises drilling mechanically.
Claim 9
Dependent Claim
13 words
The method recited in claim 1, wherein the step of drilling comprises punching.
Claim 10
Dependent Claim
24 words
The method recited in claim 1 wherein the step of metallizing the drilled vias includes providing at least one joining pad with joining metal.
Claim 11
Dependent Claim
24 words
The method recited in claim 1, wherein the step of providing a first circuitized power core comprises providing a first, undrilled, circuitized power core.
Claim 12
Dependent Claim
24 words
The method recited in claim 1, wherein the step of providing a first circuitized power core comprises providing a first, drilled, circuitized power core.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-09-01 | 1996-03-02 | 1996-09-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-09-01 | 2000-03-02 | 2000-09-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-09-01 | 2004-03-02 | 2004-09-01 | $7700.00 | Window Closed / Lapsed |