Abstract: A multi-level package, and method for making same, that offers a small size with compartmentalized areas that allow for radiation shielding is disclosed. In its simplest embodiment, the invention comprises two cards and an interposer interposed between the two cards. The interposer preferably has an opening, and the combination of the interposer's opening and the two cards form a cavity. The cavity allows for a high amount of components to be packed into a small, three-dimensional space. The interposer supports can act like a Faraday shield. The two cards and interposer can be multi-layered and support any type of chip or package connection on each side of each card or interposer, including through-hole, surface mount, and direct-chip attachment connections. Finally, pick-up plates or heat sinks can be attached to the package.

Abstract: A method and structure for a solder interconnection, using solder balls for making a low temperature chip attachment directly to any of the higher levels of packaging substrate is disclosed. After a solder ball has been formed using standard methods it is reflowed to give the solder ball a smooth surface. A layer of low melting point metal, such as, bismuth, indium or tin, preferably, pure tin, is deposited on the top of the solder balls. This structure results in localizing of the eutectic alloy, formed upon subsequent low temperature joining cycle, to the top of the high melting solder ball even after multiple low temperature reflow cycles. This method does not need tinning of the substrate to which the chip is to be joined, which makes this method economical. It has also been noticed that whenever temperature is raised slightly above the eutectic temperature, the structure always forms a liquid fillet around the joint with copper wires.

Abstract: A capacitor having a multilevel interconnection technology and process thereof. Also disclosed is a process of electrically connecting a capacitor to an object, comprising the steps of first obtaining a capacitor. At least one solder ball is reflowed and secured onto the capacitor. The solder ball is in electrical communication with the capacitor through a contacting means. On this reflowed solder ball a cap of low melting point metal is secured. This can be done in a number of ways. The preferred way is to positioning a mask over the solder ball such that a portion of the solder ball is exposed through openings in the mask. At least one layer of a low melting point metal is deposited on the exposed surface of the solder ball through the mask, and thereby forming a capacitor with a multilevel interconnect cap. The low melting point metal can interact with the surface of the solder ball to form a cap of an eutectic or a liquefied portion. The cap portion can then be joined to the object.

Abstract: A material deposition process is disclosed in which apertures of a contact mask used therein have a constricted opening terminating in a `knife edge` in a sidewall thereof near the top mask side, especially within the top 25% of the mask thickness above the substrate. A process is disclosed in which the mask, in addition, has apertures which have larger dimension lower openings on a bottom side of the mask contacting the substrate than constricted openings near the top side of the mask. Single solder bump and "bump on bump" over BLM (ball limiting metallurgy) processes are disclosed which utilize such contact mask to reduce the damage and detaching of such features during processing and subsequent handling.

Abstract: A material deposition contact mask is disclosed in which apertures formed therein have a larger dimension in lower openings in a bottom side of the mask contacting the substrate than in constricted openings located near the top side of the mask. Apertures of the contact mask have knife edges located within the upper sidewalls thereof, e.g. within the top 25% of the mask thickness above the substrate. A mask is disclosed which, in addition, is thermally compensated to the substrate temperature at which the deposition is performed. Methods for fabricating the mask by differential etching are disclosed.

Abstract: This invention is directed to a capacitor having a multilevel interconnection technology. At least one solder ball is reflowed and secured onto the capacitor. The solder ball is in electrical communication with the capacitor through a contact. On this reflowed solder ball a cap of low melting point metal is secured. This can be done in a number of ways. The preferred way is to positioning a mask over the solder ball such that a portion of the solder ball is exposed through openings in the mask. At least one layer of a low melting point metal is deposited on the exposed surface of the solder ball through the mask, and thereby forming a capacitor with a multilevel interconnect cap. The low melting point metal can interact with the surface of the solder ball to form a cap of an eutectic or a liquefied portion. The cap portion can then be joined to the object.