Sandwich assembly scheme for thin film electrode array and integrated circuits on both sides of printed circuit board (PCB) and method of manufacture

A method of manufacturing a thin film electrode receiving apparatus, the method comprising:

• providing a thin film having embedded wire traces, the wire traces leading from electrodes at a distal end of the thin film to a two-dimensional (2D) array of conductive pads, wherein some of the wire traces connect with a first row of the conductive pads and other of the wire traces connect with a second row of the conductive pads, the second row being farther from the distal end than the first row, the thin film having a hole through the thin film;
• sandwiching the thin film between a printed circuit board (PCB) having a via and an analog-to-digital converter (ADC);
• electrically connecting a first set of ADC inputs with at least one of the first and second rows of conductive pads of the thin film;
• heating and forming a solder connection running from an output of the ADC through the thin film hole to the PCB via;
• attaching an integrated circuit chip to a side of the PCB opposite the thin film and ADC;
• and
• connecting the PCB via to the integrated circuit chip.

A method of aligning and joining a thin film flex circuit with a rigid component, the method comprising:

• depositing, using a ball bonder, a bottom metal ball on a rigid component;
• stacking, using the ball bonder, another metal ball on top of the bottom metal ball to form a first pillar of stacked metal balls;
• forming, using the ball bonder, a second pillar of stacked metal balls;
• and
• aligning and placing a thin film flex circuit such that the first and second pillars of stacked metal balls project through holes in the thin film flex circuit;
• wherein the pillars keep the thin film flex circuit taut and prevent wrinkling.