The invention provides a method for attaching a flip chip to a printed wiring board. A bumped opto-electronic or electromechanical flip chip is provided. An underfill material is applied to a first portion of the flip chip, wherein a second portion of the flip chip is free of the underfill material. The flip chip is positioned on a printed wiring board, and a bumped portion of the flip chip is heated to electrically connect the flip chip to the printed wiring board. The second portion of the flip chip remains free of the underfill material when the flip chip is electrically connected to the printed wiring board.