Method for forming a microelectronic assembly

A method for forming a microelectronic assembly, the method comprising:

• fabricating a substrate that includes a via having an opening, and a contact adjacent the via remote from the opening;
• dispensing a bonding agent into the via through the opening to partially fill the via;
• applying a film onto the substrate, the film formed of a thermoset prepolymer that is curable to form a thermoset resin and covers the via and is spaced apart from the bonding agent by a gap;
• superposing an integrated circuit component comprising a conductive bump onto the substrate to form a preassembly such that the conductive bump perforates the film and extends into the partially filled via, said gap providing clearance for material of the film displaced during perforation;
• and
• heating the preassembly to bond the bonding agent to the conductive bump and to concurrently cure the film.

A method for forming a microelectronic assembly, the method comprising:

• fabricating a flexible substrate comprising a top face, a bottom face opposite the top face, a via having a predetermined volume and an opening at the top face, and a metallic bond pad closing the via at the bottom face;
• dispensing a solder paste into the via through the opening in an amount less than the predetermined volume to form a partially filed via, the solder paste comprising solder particles dispersed in a liquid vehicle;
• applying a film to the top face, the film formed of a prepolymer that is thermally curable to form an epoxy resin, the film covering the partially filled via and spaced apart from the solder paste by a gap;
• superposing an integrated circuit die onto the flexible substrate to form a preassembly comprising the film interposed between the flexible substrate and the integrated circuit die, the integrated circuit die comprising a conductive bump and being superposed such that the conductive bump perforates the film, thereby forming a portion about the body that extends into the partially filled via into contact with the solder paste, the gap providing clearance for the portion;
• heating the preassembly to coalesce the solder particles into a molten body and to concurrently cure the film and bond the film to the integrated circuit die and to the flexible substrate to form an integral microelectronic assembly;
• and
• cooling to solidify the molten body to bond the solder bump to the metallic bond pad.

A method for forming a microelectronic assembly, the method comprising:

• fabricating a flexible substrate comprising a top face, a bottom face opposite the top face, a via having an opening at the top face, and a metallic bond pad closing the via at the bottom face;
• dispensing a prepolymeric material into the via through the opening to form a partially filled via, the prepolymeric material comprising metal particulate dispersed in a conductive resin body;
• applying a film to the top face, the film formed of a prepolymer that is thermally curable to form an epoxy resin, the film covering the partially filled via and spaced apart from the solder paste by a gap;
• superposing an integrated circuit die onto the flexible substrate to form a preassembly comprising the film interposed between the flexible substrate and the integrated circuit die, the integrated circuit die comprising a conductive bump and being superposed such that the conductive bump perforates the film, thereby forming a portion about the body that extends into the partially filled via into contact with the solder paste, the gap providing clearance for the portion;
• and
• heating the preassembly to cure the prepolymeric material and to concurrently cure the film and bond the film to the integrated circuit die to the flexible substrate to form an integral microelectronic assembly.