IP Library Granted Patent US 9,560,774
Granted Patent B2
US 9,560,774 · App. 13/420,167 · Granted Jan 31, 2017

Method of fabricating a circuit board

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Quick Facts
Patent No.
US 9,560,774
App. No.
13/420,167
Granted
Jan 31, 2017
Kind
B2
Abstract

A high-speed router backplane is disclosed. The router backplane uses differential signal pairs on multiple signal layers, each sandwiched between a pair of digital ground layers. Thru-holes are used to connect the differential signal pairs to external components. To reduce routing complexity, at least some of the differential signal pairs route through a via pair, somewhere along their path, to a different signal layer. At least some of the thru-holes and vias are drilled to reduce an electrically conductive stub length portion of the hole. The drilled portion of a hole includes a transition from a first profile to a second profile to reduce radio frequency reflections from the end of the drilled hole.

Claims (14)

1. A method for manufacturing a circuit board, comprising:

providing a panel including a first major surface, a second major surface opposite the panel from the first major surface, and a first conductive layer that includes a first signaling trace having a first pad and that is located between the first major surface and second major surface;

drilling and plating the panel to provide a plated hole that extends from the first major surface to the second major surface and through the first pad of the first signaling trace;

back-drilling the plated hole from the first major surface of the panel such that a first portion of the plated hole is removed to provide a first remaining portion of the plated hole having a plated hole diameter and a first transition from the first remaining portion of the plated hole to a first portion of an unplated hole that includes a first unplated hole diameter that is larger than the plated hole diameter; and

back-drilling the first portion of the unplated hole from the first major surface of the panel to provide a second transition from the first portion of the unplated hole to a second portion of the unplated hole that includes a second unplated hole diameter that is larger than the first unplated hole diameter.

2. The method of claim 1 , wherein the second transition is located approximately halfway between the first transition and the first surface of the panel.

3. The method of claim 1 , wherein the panel includes a second conductive layer that includes a second signaling trace having a second pad and that is located between the first major surface and the second major surface, and wherein the first remaining portion of the plated hole extends through the second pad of the second signaling trace.

4. The method of claim 1 , further comprising:

back-drilling the first remaining portion of the plated hole from the second major surface of the panel such that a second portion of the plated hole is removed to provide a second remaining portion of the plated hole having the plated hole diameter and a third transition from the second remaining portion of the plated hole to a third portion of the unplated hole that includes a third unplated hole diameter that is larger than the plated hole diameter; and

back-drilling the third portion of the unplated hole from the second major surface of the panel to provide a fourth transition from the third portion of the unplated hole to a fourth portion of the unplated hole that includes a fourth unplated hole diameter that is larger than the third unplated hole diameter.

5. The method of claim 1 ,

wherein the back-drilling the plated hole from the first major surface of the panel includes drilling using a first drill bit having a diameter that is approximately equal to the first unplated hole diameter, and

wherein the back-drilling the first portion of the unplated hole from the first major surface of the panel includes drilling using a second drill bit having a diameter that is approximately equal to the second unplated hole diameter.

6. The method of claim 1 , wherein the back-drilling the plated hole from the first major surface of the panel and the back-drilling the first portion of the unplated hole from the first major surface of the panel includes using a drill bit having a first portion with a diameter that is approximately equal to the first unplated hole diameter and a second portion with a diameter that is approximately equal to the second unplated hole diameter.

Assignments (15)
RELEASE OF SECURITY INTEREST IN PATENTS PREVIOUSLY RECORDED AT REEL/FRAME (053546/0001) Recorded Jun 23, 2022
From: THE BANK OF NEW YORK MELLON TRUST COMPANY, N.A., AS NOTES COLLATERAL AGENT
To: DELL MARKETING L.P. (ON BEHALF OF ITSELF AND AS SUCCESSOR-IN-INTEREST TO CREDANT TECHNOLOGIES, INC.); DELL INTERNATIONAL L.L.C.; DELL PRODUCTS L.P.; DELL USA L.P.; EMC CORPORATION; DELL MARKETING CORPORATION (SUCCESSOR-IN-INTEREST TO FORCE10 NETWORKS, INC. AND WYSE TECHNOLOGY L.L.C.); EMC IP HOLDING COMPANY LLC
Reel/Frame 071642/0001 →
RELEASE OF SECURITY INTEREST IN PATENTS PREVIOUSLY RECORDED AT REEL/FRAME (045455/0001) Recorded May 20, 2022
From: THE BANK OF NEW YORK MELLON TRUST COMPANY, N.A., AS NOTES COLLATERAL AGENT
To: DELL MARKETING CORPORATION (SUCCESSOR-IN-INTEREST TO ASAP SOFTWARE EXPRESS, INC.); DELL MARKETING L.P. (ON BEHALF OF ITSELF AND AS SUCCESSOR-IN-INTEREST TO CREDANT TECHNOLOGIES, INC.); DELL USA L.P.; DELL INTERNATIONAL L.L.C.; DELL PRODUCTS L.P.; DELL MARKETING CORPORATION (SUCCESSOR-IN-INTEREST TO FORCE10 NETWORKS, INC. AND WYSE TECHNOLOGY L.L.C.); EMC CORPORATION (ON BEHALF OF ITSELF AND AS SUCCESSOR-IN-INTEREST TO MAGINATICS LLC); EMC IP HOLDING COMPANY LLC (ON BEHALF OF ITSELF AND AS SUCCESSOR-IN-INTEREST TO MOZY, INC.); SCALEIO LLC
Reel/Frame 061753/0001 →
RELEASE OF SECURITY INTEREST IN PATENTS PREVIOUSLY RECORDED AT REEL/FRAME (040136/0001) Recorded Apr 26, 2022
From: THE BANK OF NEW YORK MELLON TRUST COMPANY, N.A., AS NOTES COLLATERAL AGENT
To: DELL MARKETING CORPORATION (SUCCESSOR-IN-INTEREST TO ASAP SOFTWARE EXPRESS, INC.); DELL MARKETING L.P. (ON BEHALF OF ITSELF AND AS SUCCESSOR-IN-INTEREST TO CREDANT TECHNOLOGIES, INC.); DELL USA L.P.; DELL INTERNATIONAL L.L.C.; DELL PRODUCTS L.P.; DELL MARKETING CORPORATION (SUCCESSOR-IN-INTEREST TO FORCE10 NETWORKS, INC. AND WYSE TECHNOLOGY L.L.C.); EMC CORPORATION (ON BEHALF OF ITSELF AND AS SUCCESSOR-IN-INTEREST TO MAGINATICS LLC); EMC IP HOLDING COMPANY LLC (ON BEHALF OF ITSELF AND AS SUCCESSOR-IN-INTEREST TO MOZY, INC.); SCALEIO LLC
Reel/Frame 061324/0001 →
RELEASE OF SECURITY INTEREST Recorded Nov 3, 2021
From: CREDIT SUISSE AG, CAYMAN ISLANDS BRANCH
To: DELL USA L.P.; ASAP SOFTWARE EXPRESS, INC.; AVENTAIL LLC; CREDANT TECHNOLOGIES, INC.; DELL INTERNATIONAL, L.L.C.; DELL MARKETING L.P.; DELL PRODUCTS L.P.; DELL SOFTWARE INC.; DELL SYSTEMS CORPORATION; EMC CORPORATION; EMC IP HOLDING COMPANY LLC; FORCE10 NETWORKS, INC.; MAGINATICS LLC; MOZY, INC.; SCALEIO LLC; WYSE TECHNOLOGY L.L.C.
Reel/Frame 058216/0001 →
MERGER Recorded Mar 4, 2021
From: FORCE10 NETWORKS, INC.
To: DELL MARKETING CORPORATION
Reel/Frame 056104/0988 →
SECURITY AGREEMENT Recorded Mar 21, 2019
From: CREDANT TECHNOLOGIES, INC.; DELL INTERNATIONAL L.L.C.; DELL MARKETING L.P.; DELL PRODUCTS L.P.; DELL USA L.P.; EMC CORPORATION; FORCE10 NETWORKS, INC.; WYSE TECHNOLOGY L.L.C.; EMC IP HOLDING COMPANY LLC
To: THE BANK OF NEW YORK MELLON TRUST COMPANY, N.A.
Reel/Frame 049452/0223 →
SECURITY AGREEMENT Recorded Sep 21, 2016
From: ASAP SOFTWARE EXPRESS, INC.; AVENTAIL LLC; CREDANT TECHNOLOGIES, INC.; DELL USA L.P.; DELL INTERNATIONAL L.L.C.; DELL MARKETING L.P.; DELL PRODUCTS L.P.; DELL SOFTWARE INC.; DELL SYSTEMS CORPORATION; EMC CORPORATION; EMC IP HOLDING COMPANY LLC; FORCE10 NETWORKS, INC.; MAGINATICS LLC; MOZY, INC.; SCALEIO LLC; SPANNING CLOUD APPS LLC; WYSE TECHNOLOGY L.L.C.
To: CREDIT SUISSE AG, CAYMAN ISLANDS BRANCH, AS COLLATERAL AGENT
Reel/Frame 040134/0001 →
SECURITY AGREEMENT Recorded Sep 21, 2016
From: ASAP SOFTWARE EXPRESS, INC.; AVENTAIL LLC; CREDANT TECHNOLOGIES, INC.; DELL USA L.P.; DELL INTERNATIONAL L.L.C.; DELL MARKETING L.P.; DELL PRODUCTS L.P.; DELL SOFTWARE INC.; DELL SYSTEMS CORPORATION; EMC CORPORATION; EMC IP HOLDING COMPANY LLC; FORCE10 NETWORKS, INC.; MAGINATICS LLC; MOZY, INC.; SCALEIO LLC; SPANNING CLOUD APPS LLC; WYSE TECHNOLOGY L.L.C.
To: THE BANK OF NEW YORK MELLON TRUST COMPANY, N.A., AS NOTES COLLATERAL AGENT
Reel/Frame 040136/0001 →
RELEASE OF SECURITY INTEREST Recorded Sep 14, 2016
From: BANK OF AMERICA, N.A., AS COLLATERAL AGENT
To: DELL MARKETING L.P.; ASAP SOFTWARE EXPRESS, INC.; APPASSURE SOFTWARE, INC.; COMPELLENT TECHNOLOGIES, INC.; CREDANT TECHNOLOGIES, INC.; DELL INC.; DELL PRODUCTS L.P.; DELL USA L.P.; DELL SOFTWARE INC.; FORCE10 NETWORKS, INC.; PEROT SYSTEMS CORPORATION; SECUREWORKS, INC.; WYSE TECHNOLOGY L.L.C.
Reel/Frame 040040/0001 →
RELEASE OF SECURITY INTEREST Recorded Sep 14, 2016
From: BANK OF NEW YORK MELLON TRUST COMPANY, N.A., AS COLLATERAL AGENT
To: DELL MARKETING L.P.; ASAP SOFTWARE EXPRESS, INC.; APPASSURE SOFTWARE, INC.; COMPELLENT TECHNOLOGIES, INC.; CREDANT TECHNOLOGIES, INC.; DELL INC.; DELL PRODUCTS L.P.; DELL USA L.P.; DELL SOFTWARE INC.; FORCE10 NETWORKS, INC.; PEROT SYSTEMS CORPORATION; SECUREWORKS, INC.; WYSE TECHNOLOGY L.L.C.
Reel/Frame 040065/0618 →
RELEASE OF SECURITY INTEREST Recorded Sep 13, 2016
From: BANK OF AMERICA, N.A., AS ADMINISTRATIVE AGENT
To: DELL MARKETING L.P.; ASAP SOFTWARE EXPRESS, INC.; APPASSURE SOFTWARE, INC.; COMPELLANT TECHNOLOGIES, INC.; CREDANT TECHNOLOGIES, INC.; DELL INC.; DELL PRODUCTS L.P.; DELL USA L.P.; DELL SOFTWARE INC.; FORCE10 NETWORKS, INC.; PEROT SYSTEMS CORPORATION; SECUREWORKS, INC.; WYSE TECHNOLOGY L.L.C.
Reel/Frame 040065/0216 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Aug 27, 2015
From: GOERGEN, JOEL R.; HUNT, GREG
To: FORCE10 NETWORKS, INC.
Reel/Frame 036442/0376 →
PATENT SECURITY AGREEMENT (ABL) Recorded Jan 2, 2014
From: DELL INC.; APPASSURE SOFTWARE, INC.; ASAP SOFTWARE EXPRESS, INC.; BOOMI, INC.; COMPELLENT TECHNOLOGIES, INC.; CREDANT TECHNOLOGIES, INC.; DELL MARKETING L.P.; DELL PRODUCTS L.P.; DELL SOFTWARE INC.; DELL USA L.P.; FORCE10 NETWORKS, INC.; GALE TECHNOLOGIES, INC.; PEROT SYSTEMS CORPORATION; SECUREWORKS, INC.; WYSE TECHNOLOGY L.L.C.
To: BANK OF AMERICA, N.A., AS ADMINISTRATIVE AGENT
Reel/Frame 031898/0001 →
PATENT SECURITY AGREEMENT (NOTES) Recorded Jan 2, 2014
From: APPASSURE SOFTWARE, INC.; ASAP SOFTWARE EXPRESS, INC.; BOOMI, INC.; COMPELLENT TECHNOLOGIES, INC.; CREDANT TECHNOLOGIES, INC.; DELL INC.; DELL MARKETING L.P.; DELL PRODUCTS L.P.; DELL SOFTWARE INC.; DELL USA L.P.; FORCE10 NETWORKS, INC.; GALE TECHNOLOGIES, INC.; PEROT SYSTEMS CORPORATION; SECUREWORKS, INC.; WYSE TECHNOLOGY L.L.C.
To: BANK OF NEW YORK MELLON TRUST COMPANY, N.A., AS FIRST LIEN COLLATERAL AGENT
Reel/Frame 031897/0348 →
PATENT SECURITY AGREEMENT (TERM LOAN) Recorded Jan 2, 2014
From: DELL INC.; APPASSURE SOFTWARE, INC.; ASAP SOFTWARE EXPRESS, INC.; BOOMI, INC.; COMPELLENT TECHNOLOGIES, INC.; CREDANT TECHNOLOGIES, INC.; DELL MARKETING L.P.; DELL PRODUCTS L.P.; DELL SOFTWARE INC.; DELL USA L.P.; FORCE10 NETWORKS, INC.; GALE TECHNOLOGIES, INC.; PEROT SYSTEMS CORPORATION; SECUREWORKS, INC.; WYSE TECHNOLOGY L.L.C.
To: BANK OF AMERICA, N.A., AS COLLATERAL AGENT
Reel/Frame 031899/0261 →