A cryogenic under bump metallization (UBM) stack includes an adhesion and barrier layer and a conductive pillar on the adhesion and barrier layer. The conductive pillar functions as a solder wetting layer of the UBM stack and has a thickness. An indium superconducting solder bump is on the conductive pillar. The thickness of the conductive pillar is sufficient to prevent intermetallic regions, which form in the conductive pillar at room temperature due to interdiffusion, from extending through the entire thickness of the conductive pillar to maintain the structural integrity of the UBM stack. The indium (In) solder bump may be formed through electroplating, with the conductive pillar being copper (Cu) and the adhesion and barrier layer being titanium tungsten (TiW) and a thin seed layer of copper (Cu), or a layer of titanium (Ti). The UBM stack eliminates the need for magnetic materials such as nickel (Ni) in the stack, making the stack suitable for cryogenic applications.

A cryogenic under bump metallization (UBM) stack includes an adhesion and barrier layer and a conductive pillar on the adhesion and barrier layer. The conductive pillar functions as a solder wetting layer of the UBM stack and has a thickness. An indium superconducting solder bump is on the conductive pillar. The thickness of the conductive pillar is sufficient to prevent intermetallic regions, which form in the conductive pillar at room temperature due to interdiffusion, from extending through the entire thickness of the conductive pillar to maintain the structural integrity of the UBM stack. The indium (In) solder bump may be formed through electroplating, with the conductive pillar being copper (Cu) and the adhesion and barrier layer being titanium tungsten (TiW) and a thin seed layer of copper (Cu), or a layer of titanium (Ti). The UBM stack eliminates the need for magnetic materials such as nickel (Ni) in the stack, making the stack suitable for cryogenic applications.

The invention relates to a method for forming flip chip bumps using electroplating. The method allows the formation of flip chip bumps in a way that is compatible with already-formed sensitive electronic components, such as Josephson junctions, which may be used in quantum processing units. The invention also relates to a product and a flip chip package in which flip chip bumps are formed with the disclosed method.

The invention relates to a method for forming flip chip bumps using electroplating. The method allows the formation of flip chip bumps in a way that is compatible with already-formed sensitive electronic components, such as Josephson junctions, which may be used in quantum processing units. The invention also relates to a product and a flip chip package in which flip chip bumps are formed with the disclosed method.

Embodiments of a system and methods for localized high density substrate routing are generally described herein. In one or more embodiments an apparatus includes a medium, first and second circuitry elements, an interconnect element, and a dielectric layer. The medium can include low density routing therein. The interconnect element can be embedded in the medium, and can include a plurality of electrically conductive members therein, the electrically conductive member can be electrically coupled to the first circuitry element and the second circuitry element. The interconnect element can include high density routing therein. The dielectric layer can be over the interconnect die, the dielectric layer including the first and second circuitry elements passing therethrough.

Embodiments of a system and methods for localized high density substrate routing are generally described herein. In one or more embodiments an apparatus includes a medium, first and second circuitry elements, an interconnect element, and a dielectric layer. The medium can include low density routing therein. The interconnect element can be embedded in the medium, and can include a plurality of electrically conductive members therein, the electrically conductive member can be electrically coupled to the first circuitry element and the second circuitry element. The interconnect element can include high density routing therein. The dielectric layer can be over the interconnect die, the dielectric layer including the first and second circuitry elements passing therethrough.

Embodiments of a system and methods for localized high density substrate routing are generally described herein. In one or more embodiments an apparatus includes a medium, first and second circuitry elements, an interconnect element, and a dielectric layer. The medium can include low density routing therein. The interconnect element can be embedded in the medium, and can include a plurality of electrically conductive members therein, the electrically conductive member can be electrically coupled to the first circuitry element and the second circuitry element. The interconnect element can include high density routing therein. The dielectric layer can be over the interconnect die, the dielectric layer including the first and second circuitry elements passing therethrough.

Embodiments of a system and methods for localized high density substrate routing are generally described herein. In one or more embodiments an apparatus includes a medium, first and second circuitry elements, an interconnect element, and a dielectric layer. The medium can include low density routing therein. The interconnect element can be embedded in the medium, and can include a plurality of electrically conductive members therein, the electrically conductive member can be electrically coupled to the first circuitry element and the second circuitry element. The interconnect element can include high density routing therein. The dielectric layer can be over the interconnect die, the dielectric layer including the first and second circuitry elements passing therethrough.

Microelectronic assemblies, related devices and methods, are disclosed herein. In some embodiments, a microelectronic assembly may include a first microelectronic component having a first direct bonding region, wherein the first direct bonding region includes first metal contacts and a first dielectric material between adjacent ones of the first metal contacts; a second microelectronic component having a second direct bonding region, wherein the second direct bonding region includes second metal contacts and a second dielectric material between adjacent ones of the second metal contacts, wherein the first microelectronic component is coupled to the second microelectronic component by interconnects, and wherein the interconnects include individual first metal contacts coupled to respective individual second metal contacts; and a void between an individual first metal contact that is not coupled to a respective individual second metal contact, wherein the void is in the first direct bonding region.

Microelectronic assemblies, related devices and methods, are disclosed herein. In some embodiments, a microelectronic assembly may include a first microelectronic component having a first direct bonding region, wherein the first direct bonding region includes first metal contacts and a first dielectric material between adjacent ones of the first metal contacts; a second microelectronic component having a second direct bonding region, wherein the second direct bonding region includes second metal contacts and a second dielectric material between adjacent ones of the second metal contacts, wherein the first microelectronic component is coupled to the second microelectronic component by interconnects, and wherein the interconnects include individual first metal contacts coupled to respective individual second metal contacts; and a void between an individual first metal contact that is not coupled to a respective individual second metal contact, wherein the void is in the first direct bonding region.