a method for direct chip attach of a semiconductor chip to a circuit board by using solder bumps and an underfill layer is disclosed . in the method , a layer of in - situ polymeric mold material is first screen printed on the top surface of the semiconductor chip exposing a multiplicity of bond pads . the in - situ polymeric mold layer is formed with a multiplicity of apertures which are then filled with solder material in a molten solder screening process to form solder bumps . a thin flux - containing underfill material layer is then placed on top of a circuit board over a plurality of conductive pads which are arranged in a mirror image to the bond pads on the semiconductor chip . the semiconductor chip and the circuit board are then pressed together with the underfill layer inbetween and heated to a reflow temperature of higher than the melting temperature of the solder material until electrical communication is established between the bond pads and the conductive pads . in the bonded assembly , the in - situ polymeric mold layer and the underfill material layer forms a composite underfill to replace a conventional underfill material that must be injected between bonded chip and substrate by a capillary action in a time consuming process .