A bump electrode is formed on an electrode pad using a Cu core ball in which a core material is covered with solder plating, and a board which has bump electrodes such as semiconductor chip or printed circuit board mounts such a bump electrode. Flux is coated on a substrate and the bump electrodes are then mounted on the electrode pad. In a step of heating the electrode pad and the Cu core ball to melt the solder plating, a heating rate of the substrate is set to have not less than 0.01 C./sec and less than 0.3.

A bump electrode is formed on an electrode pad using a Cu core ball in which a core material is covered with solder plating, and a board which has bump electrodes such as semiconductor chip or printed circuit board mounts such a bump electrode. Flux is coated on a substrate and the bump electrodes are then mounted on the electrode pad. In a step of heating the electrode pad and the Cu core ball to melt the solder plating, a heating rate of the substrate is set to have not less than 0.01 C./sec and less than 0.3.

A method of manufacturing a bonding structure includes (a) providing a substrate, wherein the substrate includes a top surface and at least one bonding pad disposed adjacent to the top surface of the substrate, at least one bonding pad having a sloped surface with a first slope; (b) providing a semiconductor element, wherein the semiconductor element includes at least one pillar, and at least one pillar has a sidewall with a second slope, wherein the absolute value of the first slope is smaller than the absolute value of the second slope; and (c) bonding at least one pillar to a portion of the sloped surface of corresponding ones of the at least one bonding pad.

A method of manufacturing a bonding structure includes (a) providing a substrate, wherein the substrate includes a top surface and at least one bonding pad disposed adjacent to the top surface of the substrate, at least one bonding pad having a sloped surface with a first slope; (b) providing a semiconductor element, wherein the semiconductor element includes at least one pillar, and at least one pillar has a sidewall with a second slope, wherein the absolute value of the first slope is smaller than the absolute value of the second slope; and (c) bonding at least one pillar to a portion of the sloped surface of corresponding ones of the at least one bonding pad.

A semiconductor package is provided. The semiconductor package includes: a first stack including a first semiconductor substrate; a through via that penetrates the first semiconductor substrate in a first direction; a second stack that includes a second face facing a first face of the first stack, on the first stack; a first pad that is in contact with the through via, on the first face of the first stack; a second pad including a concave inner side face that defines an insertion recess, the second pad located on the second face of the second stack; and a bump that connects the first pad and the second pad, wherein the bump includes a first upper bump on the first pad, and a first lower bump between the first upper bump and the first pad.

A method for fabricating a semiconductor package may include: providing a first stack including a first pad; forming a lower bump including a first metal on the first pad; forming an upper bump including a second metal different from the first metal on the lower bump, wherein a Young's modulus of the second metal is lower than a Young's modulus of the first metal, and a melting point of the second metal is 400 degrees Celsius or higher; providing a second stack including a second pad, wherein the second pad includes a concave inner face defining an insertion recess; and bonding the first stack and the second stack by inserting the upper bump into the insertion recess of the second pad.

A microelectronic device includes a die with input/output (I/O) terminals, and a dielectric layer on the die. The microelectronic device includes electrically conductive pillars which are electrically coupled to the I/O terminals, and extend through the dielectric layer to an exterior of the microelectronic device. Each pillar includes a column electrically coupled to one of the I/O terminals, and a head contacting the column at an opposite end of the column from the I/O terminal. The head extends laterally past the column in at least one lateral direction. Methods of forming the pillars and the dielectric layer are disclosed.

A microelectronic device includes a die with input/output (I/O) terminals, and a dielectric layer on the die. The microelectronic device includes electrically conductive pillars which are electrically coupled to the I/O terminals, and extend through the dielectric layer to an exterior of the microelectronic device. Each pillar includes a column electrically coupled to one of the I/O terminals, and a head contacting the column at an opposite end of the column from the I/O terminal. The head extends laterally past the column in at least one lateral direction. Methods of forming the pillars and the dielectric layer are disclosed.