A method of making an assembly can include juxtaposing a top surface of a first electrically conductive element at a first surface of a first substrate with a top surface of a second electrically conductive element at a major surface of a second substrate. One of: the top surface of the first conductive element can be recessed below the first surface, or the top surface of the second conductive element can be recessed below the major surface. Electrically conductive nanoparticles can be disposed between the top surfaces of the first and second conductive elements. The conductive nanoparticles can have long dimensions smaller than 100 nanometers. The method can also include elevating a temperature at least at interfaces of the juxtaposed first and second conductive elements to a joining temperature at which the conductive nanoparticles can cause metallurgical joints to form between the juxtaposed first and second conductive elements.

A microelectronic device has a bump bond structure including an electrically conductive pillar with an expanded head, and solder on the expanded head. The electrically conductive pillar includes a column extending from an I/O pad to the expanded head. The expanded head extends laterally past the column on at least one side of the electrically conductive pillar. In one aspect, the expanded head may have a rounded side profile with a radius approximately equal to a thickness of the expanded head, and a flat top surface. In another aspect, the expanded head may extend past the column by different lateral distances in different lateral directions. In a further aspect, the expanded head may have two connection areas for making electrical connections to two separate nodes. Methods for forming the microelectronic device are disclosed.

A microelectronic device has a bump bond structure including an electrically conductive pillar with an expanded head, and solder on the expanded head. The electrically conductive pillar includes a column extending from an I/O pad to the expanded head. The expanded head extends laterally past the column on at least one side of the electrically conductive pillar. In one aspect, the expanded head may have a rounded side profile with a radius approximately equal to a thickness of the expanded head, and a flat top surface. In another aspect, the expanded head may extend past the column by different lateral distances in different lateral directions. In a further aspect, the expanded head may have two connection areas for making electrical connections to two separate nodes. Methods for forming the microelectronic device are disclosed.

In an MEMS device, in a Z direction that is a direction in which a first core portion, a plurality of first bump wiring, and a plurality of first individual wiring are laminated, a width between the first core portion and a wiring substrate is wider than a maximum particle diameter of solid particles contained in an adhesive, and a width between a first wiring and a second wiring and a width between a third wiring and a fourth wiring are wider than the maximum particle diameter of the solid particles.

In an MEMS device, in a Z direction that is a direction in which a first core portion, a plurality of first bump wiring, and a plurality of first individual wiring are laminated, a width between the first core portion and a wiring substrate is wider than a maximum particle diameter of solid particles contained in an adhesive, and a width between a first wiring and a second wiring and a width between a third wiring and a fourth wiring are wider than the maximum particle diameter of the solid particles.

A semiconductor device includes an interconnect substrate, an interconnect trace disposed on an upper surface of the interconnect substrate, a semiconductor chip mounted on the upper surface of the interconnect substrate, an adhesive resin layer disposed between the upper surface of the interconnect substrate and a lower surface of the semiconductor chip to bond the interconnect substrate and the semiconductor chip, the adhesive resin layer including an opening at a bottom of which an upper surface of the interconnect trace is situated, a barrier layer covering a sidewall of the opening, and conductive paste disposed inside the opening, wherein an electrode terminal of the semiconductor chip situated at the lower surface thereof is disposed inside the opening, with the conductive paste filling a space between the barrier layer and the electrode terminal.

A semiconductor device includes an interconnect substrate, an interconnect trace disposed on an upper surface of the interconnect substrate, a semiconductor chip mounted on the upper surface of the interconnect substrate, an adhesive resin layer disposed between the upper surface of the interconnect substrate and a lower surface of the semiconductor chip to bond the interconnect substrate and the semiconductor chip, the adhesive resin layer including an opening at a bottom of which an upper surface of the interconnect trace is situated, a barrier layer covering a sidewall of the opening, and conductive paste disposed inside the opening, wherein an electrode terminal of the semiconductor chip situated at the lower surface thereof is disposed inside the opening, with the conductive paste filling a space between the barrier layer and the electrode terminal.

A substrate or semiconductor device, semiconductor device assembly, and method of forming a semiconductor device assembly that includes a barrier on a solder cup. The semiconductor device assembly includes a substrate disposed over another substrate. At least one solder cup extends from one substrate towards an under bump metal (UBM) on the other substrate. The barrier on the exterior of the solder cup may be a standoff to control a bond line between the substrates. The barrier may reduce solder bridging during the formation of a semiconductor device assembly. The barrier may help to align the solder cup with a UBM when forming a semiconductor device assembly and may reduce misalignment due to lateral movement of substrates and/or semiconductor devices.

A substrate or semiconductor device, semiconductor device assembly, and method of forming a semiconductor device assembly that includes a barrier on a solder cup. The semiconductor device assembly includes a substrate disposed over another substrate. At least one solder cup extends from one substrate towards an under bump metal (UBM) on the other substrate. The barrier on the exterior of the solder cup may be a standoff to control a bond line between the substrates. The barrier may reduce solder bridging during the formation of a semiconductor device assembly. The barrier may help to align the solder cup with a UBM when forming a semiconductor device assembly and may reduce misalignment due to lateral movement of substrates and/or semiconductor devices.

A microelectronic device has a pillar connected to an external terminal by an intermetallic joint. Either the pillar or the external terminal, or both, include copper in direct contact with the intermetallic joint. The intermetallic joint includes at least 90 weight percent of at least one copper-tin intermetallic compound. The intermetallic joint is free of voids having a combined volume greater than 10 percent of a volume of the intermetallic joint; and free of a void having a volume greater than 5 percent of the volume of the intermetallic joint. The microelectronic device may be formed using solder which includes at least 93 weight percent tin, 0.5 weight percent to 5.0 weight percent silver, and 0.4 weight percent to 1.0 weight percent copper, to form a solder joint between the pillar and the external terminal, followed by thermal aging to convert the solder joint to the intermetallic joint.