Process for surface mounting flip chip carrier modules
AssigneeInternational Business Machines Corporation
InventorLawrence H. White
Life of this patent
Estimating the term…
Abstract
A process for handling and storing surface-mount, encapsulated flip-chip carrier modules to prevent the formation of amoeba-like solder bridges between the flip-chip C4 connections along the boundary between the encapsulant and the chip surface and/or between the encapsulant and the chip carrier substrate surface. The concentration of free moisture in the encapsulant is maintained below a predetermined safe limit during reflow heating used to mount the modules on a circuit board.
Claims42
A process for producing handling, and storing a surface-mount, flip-chip carrier, comprising
- the steps of:
- producing an organic chip carrier substrate;
- connecting a flip-chip directly to the chip carrier substrate using a array of reflow solder connections, with the chip separated from the substrate by a volume around the connections;
- encapsulating the volume between the flip-chip and the carrier substrate with an organic encapsulant material to protect the solder connections;
- and
- controlling the level of moisture in the encapsulant between the flip-chip and carrier substrate at a sufficiently low level for subsequent solder attachment without forming solder brides between the connections.
A process for manufacturing an interconnect assembly, comprising the steps of:
- producing an organic chip carrier substrate;
- connecting a flip-chip directly to the chip carrier substrate using an array of reflow solder connections, with the chip separated from the substrate by a volume around the connections, to form a chip carrier;
- encapsulating the volume between the flip-chip and the carrier substrate with an organic encapsulant material to protect the solder connections;
- providing a circuit board with an array of surface contacts for surface mount connection of the chip carrier;
- reflow soldering the chip carrier to surface connections of the circuit board;
- controlling the level of moisture in the encapsulant between the flip-chip and carrier substrate at a sufficiently low level for subsequent solder attachment without forming solder bridges between the connections.
A process for manufacturing an information handling system, comprising the steps of:
- producing an organic chip carrier substrate;
- connecting a flip-chip directly to the chip carrier substrate using an array of reflow solder connections, with the chip separated from the substrate by a volume around the connections to form a chip carrier;
- encapsulating the volume between the flip-chip and the chip carrier substrate with an organic encapsulant material to protect the solder connections;
- providing a circuit board with an array of surface contacts for surface mount connection of the chip carrier;
- reflow soldering the chip carrier to surface contacts of the circuit board;
- controlling the level of moisture in the encapsulant between the flip-chip and carrier substrate at a sufficiently low level for subsequent solder attachment without forming solder bridges between the connections;
- mounting the circuit board in an enclosure;
- connecting signal I/O means to the circuit board, for communicating with computer peripherals;
- connecting a power supply means to the circuit board.
A process for manufacturing an interconnect assembly, comprising the steps of:
- producing an organic carrier substrate;
- connecting a surface mount component directly to the carrier substrate using an array of reflow solder connections, with the component separated from the substrate by a volume around the connections, to form the interconnect assembly;
- encapsulating the volume between the component and the carrier substrate;
- and
- controlling the level of moisture in the encapsulant between the component and substrate at a sufficiently low level for subsequent solder attachment without forming solder bridges between the connections.
Dependencies are inferred from the claim text.