Abstract:
In a printed wiring board of the type that places a solder mask over bare copper circuit traces the solder mask is laid down with a flat planar surface by means of a liquid photopolymer solder mask layer deposited, photoexposed and developed to uncover those circuit trace positions such as through holes and connector pads for further processing. Then a very thin copper layer is chemically deposited over the surface area and a resist layer is laid down as a cover insulating layer on the flat surface so that a thicker layer of copper may be electrolytically plated over the uncovered circuit traces. In this manner the conductive area about each of the connector pads is significantly increased by plating on the sidewalls of the solder mask layer which surround the connector pads. Additionally the photopolymer flat surface is glossy and does not strongly adhere to the deposited thin copper layer as does the sidewall and conductor pad areas, thereby permitting the cover insulating layer and the thin copper layer to be readily removed from the flat planar surface by mechanical methods.
Abstract:
On a wiring substrate (1) one or more conductive linking portions (21) are applied and electrically connected to wiring layers (4) of the substrate. An insulating layer (3) covers the linking portions (21) and has openings (6) for exposing parts of the linking portions and carrier contact pads (2) connected to the linking portions (21) through holes (23a) in the insulating layer (3). Engineering changes in the electrical connection between the wiring layers (4) of the substrate (1) and outside elements (10) connected to the pads (2) can be made by selectively removing parts (21a) of the linking portions exposed in said holes (6), thereby to interrupt electrical connection, and/or by selectively contacting outward leads (7) to the pads (2).
Abstract:
In a printed circuit board, PCB (10, 30), a number of blind holes (16, 42, 44) are provided for soldering an end of a lead (20) of a component without the end of the lead extending through the PCB. Thus, a substantially flat surface is obtained. The substantially flat surface allows for good thermal contact with a heatsink and/or for miniaturization purposes. In order to allow use of common manufacturing methods the PCB according to the present invention comprises a first layer (12) and a second layer (14) arranged at a first surface (12A) of the first layer. An electrically conductive trace (18) is arranged on the first layer. The hole is arranged in the first layer, wherein the hole extends from the electrically conductive trace through the first layer, the hole being closed at the first surface of the first layer by the second layer. The hole is configured for accommodating an end of the lead and electrically connecting the lead and the trace.
Abstract:
A method of creating an active electrode that may include providing a flex circuit having an electrode made of a first material and providing a first mask over the flex circuit, the first mask having an offset region and an opening that exposes the electrode. The method may also include depositing a second material over the offset region and the opening, the second material being different from the first material an providing a second mask over the second material, the second mask having a opening over a portion of the second material that is over the offset region.