Rf Micro Devices, Inc.

T Scott Morris

Milind Shah

Donald Joseph Leahy

Mohsen Haji-Rahim

The present invention relates to a manufacturing process of a sub-module having an electromagnetic shield. Initially, a meta-module having circuitry for two or more sub-modules is formed. An overmold body is placed over the circuitry for all of the sub-modules. The overmold body of the meta-module is sub-diced to expose a metallic layer grid around each of the sub-modules. Next, an electromagnetic shield is applied to the exterior surface of the overmold body of each of the sub-modules and in contact with the metallic layer grid. The meta-module is then singulated to form modules having two or more sub-modules.

Sub-module conformal electromagnetic interference shield

The present invention provides a unique way of connecting a flip-chip die to a substrate. Initially, metallic posts are formed on the flip-chip die and solder bumps are placed on the substrate where the metallic post will ultimately connect to the substrate. The tip layer of flash gold, tin, or other wettable electroplated material is applied to the tips of the metallic posts to prevent oxidation and enhance wettability. The sides of the metallic posts are allowed to oxidize to reduce wettability. To attach the flip-chip die to the substrate, the flip-chip die is initially positioned over the substrate, such that the metallic posts align with and come into contact with the solder bumps. Once the flip-chip die is in place over the substrate, the substrate and the flip-chip are heated to cause the solder bumps to reflow and bond to the tip layers of the metallic posts.

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Clemmons, NC, United States of America

T Scott Morris