Ribbon bonding in an electronic package
A flexible conductive ribbon is ultrasonically bonded to the surface of a die and terminals from a lead frame of a package. Multiple ribbons and/or multiple bonded areas provide various benefits, such as high current capability, reduced spreading resistance, reliable bonds due to large contact areas, lower cost and higher throughput due to less areas to bond and test.
1. An electrical interconnection between a first element and a second element, including:
a first portion of a ribbon material ultrasonically bonded to a first element, the ribbon material having a rectangular cross section;
a length of the ribbon material, continuous with the first portion, extending to a second element spaced apart from the first element; and
a second portion of the ribbon material bonded to the second element,
wherein the first portion of the ribbon material ultrasonically bonded to the first element includes a first bonded portion, a second bonded portion, and a third bonded portion, the first bonded portion being closest to the second element in comparison to a position of the second bonded portion and the third bonded portion, the second bonded portion being positioned between the first bonded portion and the third bonded portion, wherein when measured in a direction along which the ribbon material extends (1) a distance between a centerline of the second bonded portion to a centerline of the first bonded portion is less than (2) a distance between a centerline of the third bonded portion to the centerline of the second bonded portion, such that a length of ribbon material between the centerline of the third bonded portion and the centerline of the second bonded portion is greater than a length of ribbon material between the centerline of the second bonded portion and the centerline of the first bonded portion.
2. The electrical interconnection of claim 1 , wherein the first element comprises a semiconductor die, and the second element comprises a substrate supporting the semiconductor die.
3. The electrical interconnection of claim 1 , wherein each of the first element and the second element comprise a semiconductor die.
4. The electrical interconnection of claim 1 , wherein the ribbon material having the rectangular cross section has a ratio of a width of the ribbon material to a thickness of the ribbon material in a range of 7-13.
5. The electrical interconnection of claim 1 , wherein the length of the ribbon material extending to the second element follows an arc shape.
6. A semiconductor package comprising:
a first element;
a second element; and
an electrical interconnection between the first element and the second element, the electrical interconnection including (a) a first portion of a ribbon material ultrasonically bonded to a first element, the ribbon material having a rectangular cross section, (b) a length of the ribbon material, continuous with the first portion, extending to the second element spaced apart from the first element, and (c) a second portion of the ribbon material bonded to the second element, wherein the first portion of the ribbon material ultrasonically bonded to the first element includes a first bonded portion, a second bonded portion, and a third bonded portion, the first bonded portion being closest to the second element in comparison to a position of the second bonded portion and the third bonded portion, the second bonded portion being positioned between the first bonded portion and the third bonded portion, wherein when measured in a direction along which the ribbon material extends (1) a distance between a centerline of the second bonded portion to a centerline of the first bonded portion is less than (2) a distance between a centerline of the third bonded portion to the centerline of the second bonded portion such that a length of ribbon material between the centerline of the third bonded portion and the centerline of the second bonded portion is greater than a length of ribbon material between the centerline of the second bonded portion and the centerline of the first bonded portion.
7. The semiconductor package of claim 6 , wherein the first element comprises a semiconductor die, and the second element comprises a substrate supporting the semiconductor die.
8. The semiconductor package of claim 6 , wherein each of the first element and the second element comprise a semiconductor die.
9. The semiconductor package of claim 6 , wherein the ribbon material having the rectangular cross section has a ratio of a width of the ribbon material to a thickness of the ribbon material in a range of 7-13.
10. The semiconductor package of claim 6 , wherein the length of the ribbon material extending to the second element follows an arc shape.