Microelectronic assemblies with integrated circuits and interposers with cavities, and methods of manufacture

Abstract

Semiconductor integrated circuits (110) or assemblies are disposed at least partially in cavities between two interposers (120). Conductive vias (204M) pass through at least one of the interposers or at least through the interposer's substrate, and reach a semiconductor integrated circuit or an assembly. Other conductive vias (204M.1) pass at least partially through multiple interposers and are connected to conductive vias that reach, or are capacitively coupled to, a semiconductor IC or an assembly. Other features are also provided.

Description

BACKGROUND OF THE INVENTION[0001]This document relates to semiconductor integrated circuits (ICs), and more particularly to assemblies with semiconductor integrated circuits.[0002]Multiple ICs can be combined in a high-density assembly to provide needed functionality. High density is desired for small assembly size and also to shorten electrical paths as needed for high speed and low power consumption. However, a small IC is a fragile device with tiny, densely packed contact pads which must be connected to possibly larger contact pads of other integrated or non-integrated (discrete) circuits. To enable such connections, an intermediate IC (interposer) can be provided. Interposers may also increase the mechanical strength of the assembly, absorb stresses generated due to differences in coefficients of thermal expansion (CTE), and improve the ability to dissipate heat that can be generated during operation or manufacture. However, interposers increase the assembly size and complexity,...

AI Technical Summary

Benefits of technology

[0009]Some manufacturing techniques described below reduce the assembly size and improve the mechanical strength and heat-dissipation capabilities of IC assemblies and intermediate structures. For example, in some embodiments, the structure of FIG. 1 is modified by providing the interposer 120.2 with a cavity on the bottom (shown as cavity 202.2 in FIG. 2), and the die 110.2 can be placed in the cavity; or the die can be placed in a cavity 202.1 in the top surface of interposer 120.1; in FIG. 2, the die enters both cavities. Therefore, the interposers 120.1 and 120.2 can be brought closer together, shortening the studs 154 interconnecting the two interposers. The assembly size is reduced, and so is the amount of encapsulant 180 (the encapsulant amount can be reduced both in the absolute terms and in the relative terms, i.e. measured as a fraction of the assembly volume). The mechanical strength is increased, partly because of the reduced size (and in particular shorter studs 154) and partly because a smaller fraction of the assembly volume is taken by the encapsulant which is softer than other parts of the assembly.

[0010]Due to the increased strength, it is easier to manufacture other circuits on inte

Problems solved by technology

However, a small IC is a fragile device with tiny, densely packed contact pads which must be connected to possibly larger contact pads of other integrated or non-integrated (discr

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