Abstract: A method of converting a land grid array (LGA) module to a ball grid array (BGA) module by removing and oxidizing portions of the LGA conductive pad features on the upper surface of the LGA module. A BGA solder ball is deposited on the remaining portion of the conductive feature of the LGA module, with subsequent reflowing of the BGA solder ball. By modifying the LGA module to support a BGA structure, excessive heat generated by components placed on the modified LGA pad can be conducted through the BGA structure and into the element on which the LGA module is attached, such as a PCB.

Abstract: Disclosed is a method of producing a flexible circuit board having gold selectively plated on only desired elements of the conductive circuits. These desired elements typically are attachment sites, such as wire bond pads or ball grid array pads, for semiconductor chips. This method eliminates the requirement to buss all circuits to a common plating contact by using a background seed metal for plating continuity. This method also provides a means to alleviate the requirement for precise registration or alignment when multiple photoresist layers are employed in order to selectively plate only a portion of the metallic elements present on the flexible circuit board. The defect of resist lifting followed by nickel/gold underplating is eliminated by conditioning the intermediate photoresist to survive the nickel/gold plating bath.

Abstract: Disclosed is a method of producing a flexible circuit board having gold selectively plated on only desired elements of the conductive circuits. These desired elements typically are attachment sites, such as wire bond pads or ball grid array pads, for semiconductor chips. This method eliminates the requirement to buss all circuits to a common plating contact by using a background seed metal for plating continuity. This method also provides a means to alleviate the requirement for precise registration or alignment when multiple photoresist layers are employed in order to selectively plate only a portion of the metallic elements present on the flexible circuit board. The defect of resist lifting followed by nickel/gold underplating is eliminated by conditioning the intermediate photoresist to survive the nickel/gold plating bath.