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AssigneeInternational Business Machines Corporation
InventorsRobert M. Japp, Mark D. Poliks
Estimating the term…
Power and ground planes that are used in Printed Circuit Boards (PCBs) and that comprise porous, conductive materials are disclosed. Using porous power and ground plane materials in PCBs allows liquids (e.g., water and/or other solvents) to pass through the power and ground planes, thus decreasing failures in PCBs (or PCBs used as laminate chip carriers) caused by cathodic/anodic filament growth and delamination of insulators. Porous conductive materials suitable for use in PCBs may be formed by using metal-coated organic cloths (such as polyester or liquid crystal polymers) or fabrics (such as those made from carbon/graphite or glass fibers), using metal wire mesh instead of metal sheets, using sintered metal, or making metal sheets porous by forming an array of holes in the metal sheets. Fabrics and mesh may be woven or random. If an array of holes is formed in a metal sheet, such an array may be formed with no additional processing steps than are performed using conventional PCB assembly methods.
A power/ground core for use in printed circuit boards the power/ground core comprising:
A printed circuit board (PCB), the PCB comprising:
A method for making a printed circuit board (PCB), the method comprising the steps of:
A method for making a printed circuit board (PCB), the method comprising the steps of:
Dependencies are inferred from the claim text.
From the US filing history. Foreign family members aren’t listed.
Backward citations are indexed for grants only.
Apparatus or processes for manufacturing printed circuits: improvement of the adhesion between the insulating substrate and the metal
By laminating two or more circuit boards: having integrally laminated metal sheets or special power cores
Plated through-holes or plated via connections: plated through-holes specially for multilayer circuits, e.g. having connections to inner circuit…
Properties and characteristics in general: porous, e.g. foam
Term end not estimated
1. Technical Field
The present invention relates generally to the field of computer manufacturing and more specifically to reducing delamination of, and cathodic/anodic filament growth on, boards used in computers.
2. Background Art
The preferred exemplary embodiment of the present invention will hereinafter be described in conjunction with the appended drawings, where like designations denote like elements, and:
FIG. 1 is a perspective view of a cross-section of a power core patterned in accordance with a preferred embodiment of the present invention;
FIG. 2 is a top view of a power core patterned in accordance with another preferred embodiment of the present invention;
The preferred embodiments of the present invention overcome the limitations of the prior art by providing Printed Circuit Boards (PCBs) having conductive, porous materials for power and ground planes. The materials are preferably porous to water and other solvents. The present invention relates to manufacturing of PCBs. A short introduction to general manufacturing techniques for PCBs will now be given, followed by the preferred embodiments.
In order to make a printed circuit board, the starting material is usually a sheet consisting of fiberglass and epoxy resin. This is often termed “prepreg” because the fiber is impregnated with resin during preliminary processing. The resin essentially acts a binder to bind fiber into a board. In place of the fiberglass cloth, it is possible to use compressed paper or other suitable materials. The basic board is therefore a flat, rigid or lightly flexible dielectric material that will be fabricated into the final printed circuit. This starting material can be laminated with a thin layer of copper on both sides of the board with suitable adhesion. The combination is commonly called copper clad laminate (CCL). These CCLs can either become simple double sided boards (having two sides of copper lines) or they can be circuitized and laminated with additional dielectric into multilayer composites.
In most cases, holes are provided through these boards (usually by drilling) to accommodate electrical connection of the various electronic components that will be attached. The holes are usually drilled using high speed drilling machines and the locations of the holes are specified in the drawings or design for the boards.