Printed circuit board with improved via design

• US 8,258,411 B2
• Filed: 08/27/2009
• Issued: 09/04/2012
• Est. Priority Date: 06/27/2002
• Status: Expired due to Fees

• Current Assignee: PPG Industries Ohio Incorporated (Nouryon BV)
• Original Assignee: PPG Industries Ohio Incorporated (Nouryon BV)
• Inventors: Wang, Alan E., Olson, Kevin C.
• Primary Examiner(s): PATEL, ISHWARBHAI B
• Application Number:
  US12/548,933
• Publication Number:
  US 20100012357A1
• Time in Patent Office: 1,104 Days
• Field of Search: 174/255
• US Class Current: 174/262
• CPC Class Codes: H01L 2224/16225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H05K 1/056 the metal substrate being covered by an organic insulating layer
• CPC Class Codes: H05K 2201/0129 Thermoplastic polymer, e.g. auto-adhesive layer; Shaping of thermoplastic polymer
• CPC Class Codes: H05K 2201/0166 Polymeric layer used for special processing, e.g. resist for etching insulating material or photoresist used as a mask during plasma etching
• CPC Class Codes: H05K 2201/0397 Tab
• CPC Class Codes: H05K 2201/0909 Preformed cutting or breaking line
• CPC Class Codes: H05K 2201/09154 Bevelled, chamferred or tapered edge
• CPC Class Codes: H05K 2201/09181 Notches in edge pads
• CPC Class Codes: H05K 2201/0919 Exposing inner circuit layers or metal planes at the side edge of the printed circuit board [PCB] or at the walls of large holes
• CPC Class Codes: H05K 2201/09554 Via connected to metal substrate
• CPC Class Codes: H05K 2201/09645 Patterning on via walls; Plural lands around one hole
• CPC Class Codes: H05K 2201/09827 Tapered, e.g. tapered hole, via or groove
• CPC Class Codes: H05K 2203/1105 Heating or thermal processing not related to soldering, firing, curing or laminating, e.g. for shaping the substrate or during finish plating
• CPC Class Codes: H05K 2203/135 Electrophoretic deposition of insulating material
• CPC Class Codes: H05K 3/002 by liquid chemical etching
• CPC Class Codes: H05K 3/0052 Depaneling, i.e. dividing a panel into circuit boards; Working of the edges of circuit boards
• CPC Class Codes: H05K 3/403 Edge contacts; Windows or holes in the substrate having plural connections on the walls thereof H05K3/4092 takes precedence
• CPC Class Codes: H05K 3/426 initial plating of through-holes in substrates without metal
• CPC Class Codes: H05K 3/44 Manufacturing insulated metal core circuits or other insulated electrically conductive core circuits H05K3/0058, H05K3/4608, and H05K3/4641 take precedence
• CPC Class Codes: H05K 3/445 having insulated holes or insulated via connections through the metal core
• CPC Class Codes: H05K 3/4614 : the electrical connections between the circuit boards being made during lamination
• CPC Class Codes: H05K 3/4641 : having integrally laminated metal sheets or special power cores
• CPC Class Codes: H05K 3/4644 : by building the multilayer layer by layer, i.e. build-up multilayer circuits making via holes in the insulating layers H05K3/0011; special circuit boards as base or core whereon the multilayer is built H05K3/4602
• CPC Class Codes: Y10T 29/49117 : Conductor or circuit manufacturing
• CPC Class Codes: Y10T 29/49124 : On flat or curved insulated base, e.g., printed circuit, etc.
• CPC Class Codes: Y10T 29/49126 : Assembling bases
• CPC Class Codes: Y10T 29/49128 : Assembling formed circuit to base
• CPC Class Codes: Y10T 29/49155 : Manufacturing circuit on or in base
• CPC Class Codes: Y10T 29/49165 : by forming conductive walled aperture in base

Abstract

A circuit board includes an electrically conductive sheet having an insulative coating surrounding the conductive sheet, with a surface of the insulative coating around an edge of the conductive sheet having an arcuate or rounded shape. At least one electrical conductor is conformally deposited on at least the rounded insulative coating around the edge of the conductive sheet and defined via photolithographic and metallization techniques. Each electrical conductor on the insulative coating thereon around the edge of the conductive sheet conforms to the arcuate or rounded shape of the insulative coating and, therefore, has an arcuate or rounded shape.

Claims

1. A circuit board comprising:

an electrically conductive sheet coated with an insulative coating that forms an insulating top layer covering one surface of the conductive sheet, an insulating bottom layer covering another surface of the conductive sheet and an insulating edge layer covering an edge of the conductive sheet;

a first electrical conductor on the insulating top layer and the insulating bottom layer and on at least part of the insulating edge layer, wherein the insulating edge layer and a portion of the first electrical conductor thereon each have an arcuate or rounded shape in a direction perpendicular to a plane of the electrically conductive sheet, and the portion of the first electrical conductor on the insulating edge layer is electrically isolated from the edge of the conductive sheet by the insulating edge layer, the combination of the portion of the first electrical conductor and the insulating edge layer it overlays being positioned in a notch defined in an outer edge of the circuit board; and

a second electrical conductor on the insulating top layer and the insulating bottom layer and on at least part of the insulating edge layer which is in the notch, wherein a portion of the second electrical conductor on the insulating edge layer is electrically isolated from the portion of the first electrical conductor in the notch, the notch has an arcuate shape in the plane of the electrically conductive sheet.

2. The circuit board of claim 1, wherein the insulative coating is initially electrodeposited and thereafter is heated until it flows thereby forming the insulating edge layer having the arcuate or rounded shape.

3. The circuit board of claim 1, further including a copper layer disposed between the electrically conductive sheet and the insulative coating.

4. A circuit board comprising:

an electrically conductive sheet including an insulating edge layer covering an edge of the conductive sheet;

wherein the insulating edge layer is in a notch in an outer edge of the circuit board;

a first electrical conductor on the insulating edge layer; and

a second electrical conductor on the insulating edge layer and electrically isolated from the first conductor, wherein the insulating edge layer and the first and second electrical conductors have an arcuate or rounded shape or outline in a direction perpendicular to a plane of″

the electrically conductive sheet, the notch has an arcuate shape in the plane of″

the electrically conductive sheet, the notch has an arcuate shape in the plane of the electrically conductive sheet.

5. The circuit board of claim 4, wherein:

the first and second electrical conductors are also on an insulating top layer overlaying a top surface of the electrically conductive sheet; and

the first and second electrical conductors are also on an insulating bottom layer overlaying a bottom surface of the electrically conductive sheet.

6. A circuit board comprising:

an electrically conductive sheet;

an insulative coating surrounding the conductive sheet with a surface of the insulative coating around an edge of the conductive sheet being rounded in a direction perpendicular to a plane of the electrically conductive sheet; and

at least two electrical conductors conformally deposited on at least the rounded insulative coating around the edge of the conductive sheet and defined via photolithographic and metallization techniques such that said electrical conductors on the rounded insulative coating around the edge of the conductive sheet have a rounded surface in a direction perpendicular to a plane of the electrically conductive sheet, wherein an outer edge of the circuit board defines a notch therein and the electrical conductors are formed on at least the rounded insulative coating in the notch, the notch has an arcuate shape in the plane of the electrically conductive sheet.