Interposer films useful in semiconductor packaging applications, and methods relating thereto

Abstract

An interposer film for IC packaging is disclosed. The interposer film comprises a substrate that supports a plurality of electrically conductive domains. The substrate is composed of a polyimide and a sub-micron filler. The polyimide is derived from at least one aromatic dianhydride component selected from rigid rod dianhydride, non-rigid rod dianhydride and combinations thereof, and at least one aromatic diamine component selected from rigid rod diamine, non-rigid rod diamine and combinations thereof. The mole ratio of dianhydride to diamine is 48-52:52-48 and the ratio of X:Y is 20-80:80-20 where X is the mole percent of rigid rod dianhydride and rigid rod diamine, and Y is the mole percent of non-rigid rod dianhydride and non-rigid rod diamine. The sub-micron filler is less than 550 nanometers in at least one dimension; has an aspect ratio greater than 3:1; is less than the thickness of the film in all dimensions.

Description

FIELD OF DISCLOSURE[0001]The present disclosure relates generally to an interposer film for integrated circuit packaging comprising a plurality of electrically conductive domains supported by a substrate. More specifically the substrate is a polyimide film comprising a sub-micron filler and a polyimide having a hybrid backbone structure.BACKGROUND OF THE DISCLOSURE[0002]IC packaging technology is applied to IC chips: (1) to provide a path for the electrical current that powers the circuits on the chip; (2) to distribute the signals on to and off of the chip; (3) to remove the heat generated directly or indirectly by the IC chip; and (4) to support and protect the chip from hostile environments. A typical ball grid array (BGA) IC package includes an IC chip affixed to a flexible polyimide interposer film. In such BGA type IC packaging applications, a thin wire bond is used to connect a pad on the IC chip to a conductive trace on the polyimide interposer film. The conductive trace is ...

AI Technical Summary

Benefits of technology

The present disclosure is about a special film used in IC packaging that has conductive domains supported by a thin substrate. The substrate is made from a special polyimide material that has been made from a combination of dianhydride and diamine components. The film also contains a small amount of a filler that is smaller than 550 nanometers and has a specific shape. The technical effect of this invention is to provide a more efficient and reliable interposer film for IC packaging.

Problems solved by technology

In such packaging applications, processing temperatures can at times be very high, e.g., above 300° C. At such high operating temperatures the interposer film can exhibit dimensional distortion.

Also, attempts to decrease processing costs can require reel-to-reel operations at increasingly higher tensions and such high tension processing can also cause an interposer film to exhibit dimensional distortion.

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