US6487083B1
Expired / Lapsed
US
⏱️ 0.0 years remaining
Multilayer circuit board
Assignee: RPX Clearinghouse LLC
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Filing: 2000-08-10
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Granted: 2002-11-26
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Expires: 2020-08-10
Abstract
Abstract A technique for improving electrical signal performance in multilayer circuit boards by eliminating the need for electrically conductive vias is disclosed. In one embodiment, the technique is realized as an improved multilayer circuit board having an electrically conductive signal layer disposed beneath at least one dielectric layer. The improvement comprises a cavity in the multilayer circuit board extending through the at least one dielectric layer so as to expose at least a portion of the electrically conductive signal layer within the cavity. The cavity is sized to accommodate an electronic component therein such that the electronic component makes electrical contact with the exposed portion of the electrically conductive signal layer, thereby eliminating the need for an electrically conductive via electrically connected to the electrically conductive signal layer and formed through the at least one dielectric layer or any other layer of the multilayer circuit board.
Inventors
- 👤 Herman Kwong
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 17:46
CPC Classifications
H; H05; H05K; H05K1/00; H05K1/18; H05K1/182; H05K1/183; H05K1/185; H05K1/186; H05K1/02; H05K1/0296; H05K1/0298; H10; H10W; H10W90/00; H10W90/701; H10W90/751; H10W90/754; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49117; Y10T29/49124; Y10T29/4913; Y10T29/49155; Y10T29/49165
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
125 words
An improved multilayer circuit board, the multilayer circuit board having an electrically conductive signal layer disposed beneath at least one dielectric layer, the improvement comprising: a cavity in the multilayer circuit board extending through the at least one dielectric layer so as to expose at least a portion of the electrically conductive signal layer within the cavity, wherein the cavity is sized to accommodate an electronic component therein such that the electronic component is mounted on and makes electrical contact with the exposed portion of the electrically conductive signal layer, thereby eliminating the need for an electrically conductive via electrically connected to the electrically conductive signal layer and formed through the at least one dielectric layer or any other layer of the multilayer circuit board.
Claim 2
Dependent Claim
125 words
An improved multilayer circuit board, the multilayer circuit board having an electrically conductive signal layer disposed beneath at least one dielectric layer, the improvement comprising: a cavity in the multilayer circuit board extending through the at least one dielectric layer so as to expose at least a portion of the electrically conductive signal layer within the cavity, wherein the cavity is sized to accommodate an electronic component therein such that the electronic component is mounted on and makes electrical contact with the exposed portion of the electrically conductive signal layer, thereby eliminating the need for an electrically conductive via electrically connected to the electrically conductive signal layer and formed through the at least one dielectric layer or any other layer of the multilayer circuit board.
Claim 3
Dependent Claim
26 words
The improved multilayer circuit board as defined in claim 1 , wherein the electronic component is one of an integrated circuit component and a discrete component.
Claim 4
Dependent Claim
35 words
The improved multilayer circuit board as defined in claim 1 , wherein at least the lateral dimensions of the cavity are sized to directly coincide with at least the lateral dimensions of the electronic component.
Claim 5
Dependent Claim
30 words
The improved multilayer circuit board as defined in claim 1 , wherein the cavity is a channel through which air may be forced for cooling at least the electronic component.
Claim 6
Dependent Claim
79 words
The improved multilayer circuit board as defined in claim 1 , wherein the electrically conductive signal layer is a first electrically conductive layer, wherein the multilayer circuit board has a second electrically conductive layer disposed above the at least one dielectric layer, wherein the cavity also extends through the second electrically conductive layer, the improvement further comprising: an electrically conductive shield electrically connected to the second electrically conductive layer for shielding electromagnetic interference to and from the electronic component.
Claim 7
Dependent Claim
24 words
The improved multilayer circuit board as defined in claim 5 , wherein the second electrically conductive layer is an electrically conductive power/ground plane layer.
Claim 8
Dependent Claim
38 words
The improved multilayer circuit board as defined in claim 5 , wherein the electrically conductive signal layer is a first electrically conductive signal layer, and wherein the second electrically conductive layer is a second electrically conductive signal layer.
Claim 9
Dependent Claim
30 words
The improved multilayer circuit board as defined in claim 5 , wherein the electrically conductive shield is in contact with the electronic component for dissipating heat from the electronic component.
Claim 10
Dependent Claim
104 words
The improved multilayer circuit board as defined in claim 5 , wherein the cavity is a first cavity, wherein the at least one dielectric layer is at least one first dielectric layer, wherein the multilayer circuit board has at least one second dielectric layer disposed above the second electrically conductive layer, the improvement further comprising: a second cavity in the multilayer circuit board extending through the at least one second dielectric layer so as to expose at least a portion of the second electrically conductive layer within the second cavity where the electrically conductive shield is electrically connected to the second electrically conductive layer.
Claim 11
Dependent Claim
29 words
The improved multilayer circuit board as defined in claim 9 , wherein the second cavity is sized so as to be larger in lateral dimension than the first cavity.
Claim 12
Dependent Claim
218 words
The improved multilayer circuit board as defined in claim 1 , wherein the multilayer circuit board is a double-sided multilayer circuit board, wherein the cavity is a first cavity on a first side of the multilayer circuit board, wherein the electrically conductive signal layer is a first electrically conductive signal layer, wherein the at least one dielectric layer is at least one first dielectric layer, wherein the electronic component is a first electronic component, wherein the multilayer circuit board has a second electrically conductive signal layer disposed beneath at least one second dielectric layer relative to a second side of the multilayer circuit board, the improvement further comprising: a second cavity on the second side of the multilayer circuit board extending through the at least one second dielectric layer so as to expose at least a portion of the second electrically conductive signal layer within the second cavity, wherein the second cavity is sized to accommodate a second electronic component therein such that the second electronic component makes electrical contact with the exposed portion of the second electrically conductive signal layer, thereby eliminating the need for an electrically conductive via electrically connected to the second electrically conductive signal layer and formed through the at least one second dielectric layer or any other layer of the multilayer circuit board.
Claim 13
Dependent Claim
27 words
The improved multilayer circuit board as defined in claim 11 , wherein the second cavity is located substantially opposite the first cavity in the multilayer circuit board.
Claim 14
Independent Claim
139 words
A method for eliminating the need for electrically conducting vias in a multilayer circuit board, the multilayer circuit board having an electrically conductive signal layer disposed beneath at least one dielectric layer, the method comprising the step of: forming a cavity in the multilayer circuit board extending through the at least one dielectric layer so as to expose at least a portion of the electrically conductive signal layer within the cavity, wherein the cavity is sized to accommodate an electronic component therein such that the electronic component is mounted on and makes electrical contact with the exposed portion of the electrically conductive signal layer, thereby eliminating the need for an electrically conductive via electrically connected to the electrically conductive signal layer and formed through the at least one dielectric layer or any other layer of the multilayer circuit board.
Claim 15
Independent Claim
139 words
A method for eliminating the need for electrically conducting vias in a multilayer circuit board, the multilayer circuit board having an electrically conductive signal layer disposed beneath at least one dielectric layer, the method comprising the step of: forming a cavity in the multilayer circuit board extending through the at least one dielectric layer so as to expose at least a portion of the electrically conductive signal layer within the cavity, wherein the cavity is sized to accommodate an electronic component therein such that the electronic component is mounted on and makes electrical contact with the exposed portion of the electrically conductive signal layer, thereby eliminating the need for an electrically conductive via electrically connected to the electrically conductive signal layer and formed through the at least one dielectric layer or any other layer of the multilayer circuit board.
Claim 16
Dependent Claim
27 words
The method as defined in claim 13 , wherein the step of forming a cavity comprises the step of: etching the cavity in the multilayer circuit board.
Claim 17
Dependent Claim
25 words
The method as defined in claim 14 , wherein the step of etching the cavity includes photolithographically etching the cavity in the multilayer circuit board.
Claim 18
Dependent Claim
25 words
The method as defined in claim 14 , wherein the step of etching the cavity includes plasma etching the cavity in the multilayer circuit board.
Claim 19
Dependent Claim
27 words
The method as defined in claim 13 , wherein the step of forming a cavity comprises the step of: milling the cavity in the multilayer circuit board.
Claim 20
Dependent Claim
25 words
The method as defined in claim 17 , wherein the step of milling the cavity includes laser ablating the cavity in the multilayer circuit board.
Claim 21
Dependent Claim
52 words
The method as defined in claim 13 , wherein the step of forming a cavity comprises the step of: prefabricating the at least one dielectric layer such that the cavity is formed upon assembly of the electrically conductive signal layer and the at least one dielectric layer in the multilayer circuit board.
Claim 22
Dependent Claim
79 words
The method as defined in claim 13 , wherein the electrically conductive signal layer is a first electrically conductive layer, wherein the multilayer circuit board has a second electrically conductive layer disposed above the at least one dielectric layer, wherein the cavity also extends through the second electrically conductive layer, the method further comprising the step of: electrically connecting an electrically conductive shield to the second electrically conductive layer for shielding electromagnetic interference to and from the electronic component.
Claim 23
Dependent Claim
105 words
The method as defined in claim 20 , wherein the cavity is a first cavity, wherein the at least one dielectric layer is at least one first dielectric layer, wherein the multilayer circuit board has at least one second dielectric layer disposed above the second electrically conductive layer, the method further comprising the step of: forming a second cavity in the multilayer circuit board extending through the at least one second dielectric layer so as to expose at least a portion of the second electrically conductive layer within the second cavity where the electrically conductive shield is electrically connected to the second electrically conductive layer.
Claim 24
Dependent Claim
216 words
The method as defined in claim 13 , wherein the multilayer circuit board is a double-sided multilayer circuit board, wherein the cavity is a first cavity on a first side of the multilayer circuit board, wherein the electrically conductive signal layer is a first electrically conductive signal layer, wherein the at least one dielectric layer is at least one first dielectric layer, wherein the electronic component is a first electronic component, wherein the multilayer circuit board has a second electrically conductive signal layer disposed beneath at least one second dielectric layer relative to a second side of the multilayer circuit board, the method further comprising: forming a second cavity on the second side of the multilayer circuit board extending through the at least one second dielectric layer so as to expose at least a portion of the second electrically conductive signal layer within the second cavity, wherein the second cavity is sized to accommodate a second electronic component therein such that the second electronic component makes electrical contact with the exposed portion of the second electrically conductive signal layer, thereby eliminating the need for an electrically conductive via electrically connected to the second electrically conductive signal layer and formed through the at least one second dielectric layer or any other layer of the multilayer circuit board.
References Cited (Backward Citations)
US4296456A
Cited
US5285352A
Cited
US5371321A
Cited
US5450046A
Cited
US5359488A
Cited
US5420460A
Cited
US5679978A
Cited
US5567654A
Cited
US5625166A
Cited
US5798014A
Cited
US5994771A
Cited
US5796165A
Cited
US5831810A
Cited
US6225570B1
Cited
US6107683A
Cited
US6121679A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2005-11-25 | 2006-05-27 | 2006-11-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2009-11-25 | 2010-05-27 | 2010-11-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2013-11-25 | 2014-05-27 | 2014-11-26 | $7700.00 | Window Closed / Lapsed |