PRINTED CIRCUIT BOARD

• US 20070184675A1
• Filed: 02/06/2007
• Published: 08/09/2007
• Est. Priority Date: 02/06/2006
• Status: Active Grant

• Current Assignee: Canon Ayutthaya Limited (Canon Inc.)
• Original Assignee: Canon Ayutthaya Limited (Canon Inc.)
• Inventors: ISHIKAWA, Koji
• Granted Patent: US 7,445,456 B2
• Time in Patent Office: Days
• US Class Current: 439/61
• CPC Class Codes: H05K 2201/09181 Notches in edge pads
• CPC Class Codes: H05K 2201/09727 Varying width along a single conductor; Conductors or pads having different widths
• CPC Class Codes: H05K 2201/0989 Coating free areas, e.g. areas other than pads or lands free of solder resist
• CPC Class Codes: H05K 3/3452 Solder masks
• CPC Class Codes: H05K 3/363 by soldering

Abstract

A highly reliable printed circuit board which is capable of preventing a short circuit between traces from being caused by a solder bridge formed by excess solder. The printed circuit board has a solder resist covering copper foil traces formed on a substrate and the substrate, for insulation. The solder resist is formed such that exposed portions of the substrate between adjacent ones of the conductive traces each have a shape protruding in a direction of where the other printed circuit board is connected, with respect to exposed portions of the adjacent ones of the conductive traces, in a boundary between the connection part and a portion on which an insulating layer is formed.

Claims

1. A printed circuit board comprising:

a substrate as a base of a printed circuit board;

a plurality of conductive traces formed on said substrate;

an insulating layer covering said conductive traces and said substrate, for insulation; and

a connection part for connection with another printed circuit board, said connection part being not covered with said insulating layer but having said conductive traces and said substrate exposed therefrom,

wherein said insulating layer is formed such that exposed portions of said substrate between adjacent ones of said conductive traces each have a shape protruding in a direction of where the other printed circuit board is connected, with respect to exposed portions of the adjacent ones of said conductive traces, in a boundary between said connection part and a portion on which said insulating layer is formed.

2. A printed circuit board according to claim 1, wherein said conductive traces are each formed to have a trace width progressively reduced from said connection part toward the portion on which said insulating layer is formed.

3. A printed circuit board comprising:

a substrate as a base of a printed circuit board;

a plurality of conductive traces formed on said substrate;

an insulating layer covering said conductive traces and said substrate, for insulation; and

a connection part for connection with another printed circuit board, said connection part being not covered with said insulating layer but having said conductive traces and said substrate exposed therefrom,

wherein said insulating layer is formed such that portions for covering between said conductive traces on said substrate each have a shape recessed in a direction of where the other printed circuit board is connected, with respect to portions for covering said conductive traces, in a boundary between said connection part and a portion on which said insulating layer is formed.

4. A printed circuit board according to claim 3, wherein said conductive traces are each formed to have a trace width progressively reduced from said connection part toward the portion on which said insulating layer is formed.

5. A printed circuit board comprising:

a substrate as a base of a printed circuit board;

a plurality of conductive traces formed on said substrate;

an insulating layer covering said conductive traces and said substrate, for insulation; and

a connection part for connection with another printed circuit board, said connection part being not covered with said insulating layer but having said conductive traces and said substrate exposed therefrom,

wherein said insulating layer is formed such that substrate portions between said insulated conductive traces are exposed in a boundary between said connection part and a portion on which said insulating layer is formed.

6. A printed circuit board according to claim 5, wherein said conductive traces are each formed to have a trace width progressively reduced from said connection part toward the portion on which said insulating layer is formed.