Abstract: An electronic module having enhanced adhesion at the chip passivation and underfill interface is disclosed. The surface of the chip passivation is chemically modified to a sufficient depth such that the cured passivation is more reactive. The modified surface is treated with a polyamine preferably having a cyclic amine group extending from a preferably aliphatic backbone. During reflow of the solder joints of the electronic module by heating, the modified passivation reacts with the polyamine at the amine functionality. Following underfill of the electronic module with a polymeric material, preferably an epoxy resin, the polyamine on the surface of the passivation reacts with the underfill material during curing of the underfill material. The resulting electronic module is more robust since the amine acts as a chemical anchoring site for both the modified passivation and the underfill material.

Abstract: An encapsulated semiconductor chip module. The chip module has the overlying encapsulant adhered directly and integrally to bare portions of the substrate to which the chip is mounted. This configuration enhances the adhesion and inhibits unintended delamination of the encapsulant from the balance of the module. The module is made by patterning anchor openings into the solder mask. The anchor openings expose corresponding portions of the substrate. It is important to locate the anchor openings over parts of the substrate that do not have circuitry on them, that is, on bare portions, so as to avoid corrosion or contamination of the circuit connections.

Abstract: Solder bumps on electronic components are encapsulated before attachment to a substrate or component carrier. A film of sealing material is pressed against top portions of the solder bumps by pressing with a layer of low durometer flexible material. Encapsulant is positioned between the component and the film and in contact with the bumps, and partially cured. The film and layer of flexible material are removed to expose the top portions of the encapsulated solder bumps.

Abstract: A method for forming a flip-chip-on-board assembly. An integrated circuit (IC) chip having a polyimide passivation layer is joined to a chip carrier via a plurality of solder bumps which electrically connect a plurality of contact pads on the IC chip to corresponding contacts on the chip carrier. A space is formed between a surface of the passivation layer and a surface of the chip carrier. A plasma is applied, to chemically modify the a surface of the chip carrier and the passivation layer of the IC chip substantially without roughening the surface of the passivation layer. The plasma is either an O.sub.2 plasma or a microwave-generated Ar and N.sub.2 O plasma. An underfill encapsulant material is applied to fill the space. The plasma treatment may be performed after the step of joining. Then, the chip and chip carrier are treated with the plasma simultaneously. Alternatively, the IC chip and chip carrier may be treated with the plasma before they are joined to one another.