Method, apparatus, and structure for determining interposer thickness

摘要

The present invention includes the following steps: setting the thickness of an interposer to an initial value; determining the axial force of the interposer and the radius of curvature of the warpage caused by the difference in the thermal expansion coefficients of the supporting substrate, the joined layer and the interposer at the set thickness; determining the absolute value of the stress on the chip-connecting surface of the interposer from the stress due to the axial force of the interposer and the stress due to the warpage using the determined axial force and the radius of curvature; determining whether or not the absolute value of the stress is within a tolerance; changing the thickness of the interposer by a predetermined value; and confirming the set thickness as the thickness of the interposer when the determined absolute value of the stress is within the tolerance.

主权项

1. A chip mounting structure comprising:
a flip chip, an interposer whose obverse surface is connected to the flip chip, a supporting substrate connected to the reverse surface of the interposer, and a joined layer provided between the interposer and the supporting substrate, wherein the thickness of the interposer is determined by:
setting the thickness of the interposer to an initial value;determining an axial force of the interposer and a radius of curvature of a warpage caused by a difference in thermal expansion coefficients of the supporting substrate, the joined layer, and the interposer at the set thickness;determining, using the determined axial force and radius of curvature, the absolute value of a first stress on a chip-connecting surface of the interposer from a second stress due to the axial force of the interposer and a third stress due to the warpage;determining whether the absolute value of the first stress is within a tolerance;changing the thickness of the interposer by a predetermined value, when the determined absolute value of the first stress is not within the tolerance, and repeating the steps of determining the axial force of the interposer and the radius of curvature, determining the absolute value of the first stress on the chip-connecting surface of the interposer, and determining whether the determined absolute value of the first stress is within the tolerance; andconfirming the set thickness as the thickness of the interposer when determined absolute value of the first stress is within the tolerance.