Method of making ball grid array package with deflectable interconnect
AssigneeMicron Technology, Inc.
InventorTimothy L. Jackson
Life of this patent
Estimating the term…
Abstract
A package for connecting an integrated circuit to a printed circuit board. The package includes an interconnect having a deflectable cantilever and a solder bump. When the integrated circuit is affixed to the interconnect, the solder bump deflects the cantilever. When the solder bump is heated such that the solder reflows, the cantilever springs toward its non-deflected position and is at least partially absorbed by the reflowing solder.
Claims16
A method of forming a ball grid array package for an integrated circuit by electrically connecting a plurality of integrated circuit pads to a plurality of solder balls, the method comprising:
- forming a plurality of conductive flaps over a pocket on a first side of an insulating tape, wherein the pocket is configured to at least partially accept a solder bump electrically connected to a pad of an integrated circuit;
- forming a conductive trace terminating on second side of the insulating tape at a solder ball, wherein the conductive trace electrically connects the solder ball to the conductive flaps;
- attaching the integrated circuit to the insulating tape through an attachment layer having a thickness less than a diameter of the solder bump such that when attached, the solder bump deflects a deflectable portion of each conductive flap into the pocket, thereby creating a compliant connection between the integrated circuit and the conductive flaps when the solder bump is activated;
- and
- activating the solder bump to form a ball grid array package for the integrated circuit.
A method of forming a ball grid array package for an integrated circuit, the method comprising:
- providing an integrated circuit having pads each pad being electrically connected to one of an array of solder bumps,
- providing an interposer including a plurality of deflectable conductive cantilevers positioned over a plurality of openings in the interposer, each deflectable conductive cantilever electrically communicating with interconnect routed to ones of a plurality of solder ball connections;
- affixing an array of solder balls to the plurality of solder ball connections;
- and
- forming a ball grid array package for the integrated circuit by affixing the integrated circuit to the interposer with an adhesive having a thickness less than the diameter of the one or more of the array of solder bumps, thereby deflecting the deflectable conductive cantilevers to form electrical connections from the integrated circuit to array of the solder balls.
A method of enhancing an electrical connection between an integrated circuit and an array of solder balls in a ball grid array package the method comprising:
- positioning an integrated circuit terminating in a plurality of solder connections having a thickness, over a plurality of interconnects extended over pockets in a tape, wherein the interconnects electrically connect to an array of solder balls on one side of the tape, wherein at least two interconnects extend over each pocket;
- combining the integrated circuit with the tape using an adhesive having a thickness less that the thickness of the solder connections such that the plurality of interconnects are deflected into the pockets in the tape by the solder connections;
- and
- activating the solder connections to allow the plurality of interconnects to spring towards their original position now inside the activated solder connections, thereby forming an ball grid array package for the integrated circuit.
A method for forming a ball grid array (BGA) package for an integrated circuit, the method comprising:
- forming a first pocket in a first side of an interposer;
- forming a second pocket in a second side of the interposer;
- tracing an interconnect in the interposer such that a plurality of conductive flaps extend over a portion of the first pocket forming a plurality of cantilevers;
- affixing an integrated circuit to the first side of the interposer using an adhesive having a thickness such that a solder bump attached to the integrated circuit deflects the cantilevers into the first pocket;
- at least partially absorbing the cantilevers into the solder bump;
- and
- affixing a solder ball at least partially within the second pocket, wherein the solder ball electrically connects to the interconnect, thereby forming a BGA package for the integrated circuit.
Dependencies are inferred from the claim text.