Abstract: A multi-chip device includes a first material within a substrate. The first material has a first coefficient of thermal expansion different than a second coefficient of thermal expansion of the substrate. A first chip overlies a first portion of the first material and a first portion of the substrate. A second chip overlies a second portion of the first material and a second portion of the substrate. The first material is between the first portion of the substrate and the second portion of the substrate.

Abstract: A semi-automatic manhole assembly assisted by a hydraulic device consists essentially of a circular frame (1), a cover (2) provided on the top, a hydraulic device (3) and a supporting unit (5) provide therebetween and jointed with both the frame (1) and cover (2) respectively, and a locking mechanism (4) disposed on an opposite end of the hydraulic device (3) and supporting unit (5) for sealing the cover (2) and frame (1) tightly. The supporting unit (5) is partially concealed within a trough (2), disposed at the bottom of the frame (1), and the hydraulic device (3) is prestored with pressure to lift the cover (2) when the locking mechanism (4) is released.

Abstract: A manhole assembly which is designed to be opened with less strength consists of a circular frame (1) with a cup (11) provided on an end, and a cover (2) with an arm (21) which joints said cup (11) provided on an end thereof, characterized in that a first bracket (12) is disposed in an inner wall of the frame (1) where the cup (11) is provided, and a second bracket (22) is provided on a bottom of the cover (2). A hydraulic device (3) is provide therebetween and pin joints with both first and second brackets (12, 22) respectively, and a locking mechanism (4) is disposed on an opposite end of the arm (21) for sealing the cover (2) and frame (1) tightly.