Methods and apparatus for an assembly having first and second circuit cards mated together with a ball stack on the first circuit card extending into a through hole in the second circuit card. A wirebond connects the first ball stack to a bond pad on the first surface of the second circuit card forming a low profile connector-less interconnect. The ball stack comprises at least two balls stacked on top of each other and bonded to each other, wherein the balls are generated from wire.

A bonding tool that executes an ultrasonic vibration processing of applying ultrasonic vibration to an application portion on a lead wire from a direct contact tip portion and a pair of press mechanisms having a pair of press rollers capable of performing a rotational operation. The pair of press mechanisms executes a press processing of pressing both sides of the application portion on the lead wire by the pair of press rollers at a time of execution of the ultrasonic vibration processing by the bonding tool and a movement processing of executing a rotational operation performed by the pair of press rollers to move the pair of press rollers on the lead wire while pressing the lead wire at a time of non-execution of the ultrasonic vibration processing.

Systems and methods for cold forming one or more features (106) in a flex circuit (100). The flex circuit (100) includes: an electronic circuit (102) connected to a substrate (104). When the substrate (104) is in a planar state, one or more areas deemed to be bent (or otherwise augmented) in the cold forming process, are additionally and selectively plated with an extra layer of metal (108), such as copper, so that only these one or more areas are now capable of being cold formed into shapes accurately.

A bonding tool that executes an ultrasonic vibration processing of applying ultrasonic vibration to an application portion on a lead wire from a direct contact tip portion and a pair of press mechanisms having a pair of press rollers capable of performing a rotational operation. The pair of press mechanisms executes a press processing of pressing both sides of the application portion on the lead wire by the pair of press rollers at a time of execution of the ultrasonic vibration processing by the bonding tool and a movement processing of executing a rotational operation performed by the pair of press rollers to move the pair of press rollers on the lead wire while pressing the lead wire at a time of non-execution of the ultrasonic vibration processing.

An electronic circuit, comprising at least three circuit boards (2.1, 2.2, 2.3) fastened at a frame (1) and electrically connected via contact pins (7) arranged therein, and an electric connection (11), connected to a third of the circuit boards (2.1). The circuit shall show a low structural space and here be cost-effective in its production and assembly. The circuit boards (2.1, 2.2, 2.3) are arranged in levels parallel in reference to each other and are fastened at a predetermined mutual distance at the frame (1), with bases (4, 5, 6) being embodied at the faces of the frame (1), with the ends being parallel to the faces of at least two of the bases (4, 5, 6) in one level, arranged in groups, and with the embodiment of the frame (1) and the circuit boards (2.1, 2.2, 2.3) being adjusted to each other.