Methods of fluxless micro-piercing of solder balls, and resulting devices
View Patent ↗A method of establishing conductive connections is disclosed. The method includes providing an integrated circuit die having a plurality of solder balls each of which has an oxide layer on an outer surface of the solder ball. The method also includes performing a heating process to heat at least the solder balls and applying a force causing each of a plurality of piercing bond structures on a substrate to pierce one of the solder balls and its associated oxide layer to thereby establish a conductive connection between the solder ball and the piercing bond structure.
1. A device, comprising:
a microelectronic component having a plurality of solder balls conductively coupled to bond pads on the microelectronic component, each of the solder balls having an oxide layer on its outer surface;
a substrate having a first side and a second side facing away from the first side, the substrate having a plurality of piercing bond structures at the first side of the substrate, each of the piercing bond structures configured for penetrating the corresponding oxide layer and extending partially into the corresponding solder ball to establish a conductive connection, wherein the piercing bond structures have an outer surface that surrounds a solid core of conductive material, wherein the outer surface includes an anti-oxidation material;
a contact pad at the second side of the substrate;
a wiring trace electrically coupling the piercing bond structure with the contact pad;
a non-conductive paste at the first side of the substrate; and
a standoff structure positioned between the microelectronic component and the substrate, wherein the standoff structure spaces the microelectronic device apart from the substrate by a predetermined distance,
wherein the anti-oxidation material is a first anti-oxidation material, the device further including a second anti-oxidation material over the first anti-oxidation material, and
wherein the first anti-oxidation material is gold and the second anti-oxidation material is nickel.
2. The device of claim 1 wherein the piercing bond structure has a first end facing the first side of the substrate and a second end facing away from the first end, and wherein the second end has a pointed cross-section.
3. The device of claim 1 wherein the piercing bond structure has a first end facing the first side of the substrate and a second end facing away from the first end, and wherein the second end has a rounded cross-section.
4. The device of claim 1 wherein the substrate includes a via extending from the first side of the substrate to the second side of the substrate, wherein the wiring trace and a dielectric material are inside the via.
5. The device of claim 1 , further comprising a plurality of piercing bond structures at the first side of the substrate, the plurality of piercing bond structures having substantially triangular cross-sections.
6. The device of claim 1 , further comprising a non-conductive paste at the first side of the substrate.
7. A device, comprising:
a microelectronic component having a plurality of solder balls conductively coupled to bond pads on the microelectronic component, each of the solder balls having an oxide layer on its outer surface;
a substrate having a first side and a second side facing away from the first side, the substrate having a plurality of piercing bond structures at the first side of the substrate, each of the piercing bond structures configured for penetrating the corresponding oxide layer and extending partially into the corresponding solder ball to establish a conductive connection, wherein the piercing bond structures have an outer surface that includes an anti-oxidation material;
a contact pad at the second side of the substrate;
a wiring trace electrically coupling the piercing bond structure with the contact pad;
a non-conductive paste at the first side of the substrate; and
a standoff structure positioned between the microelectronic component and the substrate, wherein the standoff structure spaces the microelectronic device apart from the substrate by a predetermined distance,
wherein the piercing bond structure has a first end facing the first side of the substrate and a second end facing away from the first end, and wherein the second end has a cross-section with multiple peaks.