An electronic device includes a first electronic part, a second electronic part opposite the first electronic part, and a bonding portion between the first electronic part and the second electronic part. The bonding portion contains a solder containing a substance whose crystal structure reversibly changes in temperature rise and fall processes which accompany the operation of the electronic device or electronic equipment including the electronic device. A change in the crystal structure of the substance contained in the solder promotes recovery and recrystallization of the solder in the temperature rise and fall processes which accompany the operation of the electronic device or the electronic equipment. As a result, the coarsening of crystal grains in the solder is suppressed.

An approach to provide an electronic assembly process that includes receiving at least one electronic assembly after a solder reflow process using a Sn-containing solder and a water-soluble flux. The approach includes baking the at least one electronic assembly in an oxygen containing environment and, then cleaning the at least one electronic assembly in an aqueous cleaning process.

An approach to provide an electronic assembly process that includes receiving at least one electronic assembly after a solder reflow process using a Sn-containing solder and a water-soluble flux. The approach includes baking the at least one electronic assembly in an oxygen containing environment and, then cleaning the at least one electronic assembly in an aqueous cleaning process.

A method of ultrasonically bonding semiconductor elements includes the steps of: (a) aligning surfaces of a plurality of first conductive structures of a first semiconductor element to respective surfaces of a plurality of second conductive structures of a second semiconductor element; and (b) ultrasonically bonding ones of the first conductive structures to respective ones of the second conductive structures. A bonding surface of at least one of the first conductive structures and the second conductive structures includes a frangible coating.

A method of ultrasonically bonding semiconductor elements includes the steps of: (a) aligning surfaces of a plurality of first conductive structures of a first semiconductor element to respective surfaces of a plurality of second conductive structures of a second semiconductor element; (b) ultrasonically forming tack bonds between ones of the first conductive structures and respective ones of the second conductive structures; and (c) forming completed bonds between the first conductive structures and the second conductive structures.

The present invention relates to an adhesive film for a semiconductor that can more easily bury unevenness such as through wires of a semiconductor substrate or a wire attached to a semiconductor chip and the like, and yet can be applied to various cutting methods without specific limitations to realize excellent cuttability, thus improving reliability and efficiency of a semiconductor packaging process.

An underfill material enabling voidless packaging and excellent solder bonding properties, and a method for manufacturing a semiconductor device using the same are provided. An underfill material is used which contains an epoxy resin and a curing agent, and a time for a reaction rate to reach 20% at 240 C. calculated by Ozawa method using a differential scanning calorimeter is 2.0 sec or less and a time for the reaction rate to reach 60% is 3.0 sec or more. This enables voidless packaging and excellent solder connection properties.

The present invention relates to an adhesive composition for a semiconductor including: a thermoplastic resin having a glass transition temperature of 10 C. to 20 C.; a curing agent containing a phenol resin having a softening point of 70 C. or more; a solid epoxy resin; and a liquid epoxy resin, wherein a weight ratio of the total contents of the solid epoxy resin and the liquid epoxy resin to the thermoplastic resin is 1.6 to 2.6, an adhesive film for a semiconductor including the adhesive composition for a semiconductor, a dicing die bonding film including an adhesive layer including the adhesive composition for a semiconductor, and a method for dicing a semiconductor wafer using the dicing die bonding film.

A method of ultrasonically bonding semiconductor elements includes the steps of: (a) aligning surfaces of a plurality of first conductive structures of a first semiconductor element to respective surfaces of a plurality of second conductive structures of a second semiconductor element; and (b) ultrasonically bonding ones of the first conductive structures to respective ones of the second conductive structures. A bonding surface of at least one of the first conductive structures and the second conductive structures includes a frangible coating.

A method of ultrasonically bonding semiconductor elements includes the steps of: (a) aligning surfaces of a plurality of first conductive structures of a first semiconductor element to respective surfaces of a plurality of second conductive structures of a second semiconductor element; (b) ultrasonically forming tack bonds between ones of the first conductive structures and respective ones of the second conductive structures; and (c) forming completed bonds between the first conductive structures and the second conductive structures.