摘要:
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 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 O2 plasma or a microwave-generated Ar and N2O 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. The plasma treatment improves adhesion between the encapsulant and the IC chip, and between the encapsulant and the chip carrier.
摘要:
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 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 O2 plasma or a microwave-generated Ar and N2O 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 treat with the plasma before they are joined to one another. The plasma treatment improves adhesion between the encapsulant and the IC chip, and between the encapsulant and the chip carrier.
摘要:
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. The plasma treatment improves adhesion between the encapsulant and the IC chip, and between the encapsulant and the chip carrier.
摘要:
A metal alloy solder ball comprising a first metal and a second metal, the first metal having a sputtering yield greater than the second metal. The solder ball comprises a bulk portion having a bulk ratio of the first metal to the second metal, an outer surface, and a surface gradient having a depth and a gradient ratio of the first metal to the second metal that is less than the bulk ratio. The gradient ratio increases along the surface gradient depth from a minimum at the outer surface. The solder ball may be formed by the process of exposing the ball to energized ions of a sputtering gas for an effective amount of time to form the surface gradient.
摘要:
A process for altering surface properties of a mass of metal alloy solder comprising a first metal and a second metal. The process comprises exposing the mass to energized ions to preferentially sputter atoms of the first metal to form a surface layer ratio of first metal to second metal atoms that is less than the bulk ratio. The solder may be located on the surface of a substrate, wherein the process may further comprise masking the substrate to shield all but a selected area from the ion beam. The sputtering gas may comprises a reactive gas such as oxygen and the substrate may be an organic substrate. The process may further comprise simultaneously exposing the organic substrate to energized ions of the reactive gas to roughen the organic substrate surface.
摘要:
A process for altering surface properties of a mass of metal alloy solder comprising a first metal and a second metal. The process comprises exposing the mass to energized ions to preferentially sputter atoms of the first metal to form a surface layer ratio of first metal to second metal atoms that is less than the bulk ratio. The solder may be located on the surface of a substrate, wherein the process may further comprise masking the substrate to shield all but a selected area from the ion beam. The sputtering gas may comprises a reactive gas such as oxygen and the substrate may be an organic substrate. The process may further comprise simultaneously exposing the organic substrate to energized ions of the reactive gas to roughen the organic substrate surface.
摘要:
A method for bonding heat sinks to packaged electronic components comprises the steps of: (a) exposing to a plasma a surface of a molded polymer formed on a substrate; (b) allowing the plasma to at least partially convert silicon-containing residue on the surface to silica; and (c) bonding an article to the surface by applying an adherent between the article and the surface. Often, the silicon-containing residue is silicone oil, a mold release compound, which may prevent the formation of a bond when using conventional bonding methods and materials. The silica layer formed on the surface of the molded polymer assists in formation of a proper bond. The plasma may be an oxygen plasma and the adherent may be selected from either a heat cured silicone-based paste adhesive with a metal oxide filler or a heat cured porous polymer film impregnated with adhesive. In particular, the film may be polytetrafluoroethylene, the adhesive may be polybutadine, and the film may be further impregnated with a metal oxide heat transfer medium, such as zinc oxide. An alternate method comprises applying the porous polymer film without plasma treatment and heat curing the film to form a proper bond.
摘要:
A semiconductor printed circuit board assembly (PCBA) and method for making same for use in electronic packages having a core layer of copper-invar-copper (CIC) with a layer of dielectric substrate placed on the core layer. A second layer of dielectric substrate is placed on the lower surface of the core layer of CIC. The layers are laminated together. Blind vias are laser drilled into the layers of dielectric substrate. The partially completed PCBA is subjected to a reactive ion etch (RIE) plasma as a first step to clean blind vias in the PCBA. After the plasma etch, an acidic etchant liquid solution is used on the blind vias. Pre-plating cleaning of blind vias removes a majority of oxides from the blind vias. Seed copper layers are then applied to the PCBA, followed by a layer of copper plating that can be etched to meet the requirements of the PCBA.
摘要:
A method of treating a conductive layer to assure enhanced adhesion of the layer to selected dielectric layers used to form a circuitized substrate. The conductive layer includes at least one surface with the appropriate roughness to enable such adhesion and also good signal passage if the layer is used as a signal layer. The method is extendible to the formation of such substrates, including to the formation of multilayered substrates having many conductive and dielectric layers. Such substrates may include one or more electrical components (e.g., semiconductor chips) mounted thereon and may also be mounted themselves onto other substrates.
摘要:
A method for bonding heat sinks to packaged electronic components comprises the steps of: (a) exposing to a plasma a surface of a molded polymer formed on a substrate; (b) allowing the plasma to at least partially convert silicon-containing residue on the surface to silica; and (c) bonding an article to the surface by applying an adherent between the article and the surface. Often, the silicon-containing residue is silicone oil, a mold release compound, which may prevent the formation of a bond when using conventional bonding methods and materials. The silica layer formed on the surface of the molded polymer assists in formation of a proper bond. The plasma may be an oxygen plasma and the adherent may be selected from either a heat cured silicone-based paste adhesive with a metal oxide filler or a heat cured porous polymer film impregnated with adhesive. In particular, the film may be polytetrafluoroethylene, the adhesive may be polybutadine, and the film may be further impregnated with a metal oxide heat transfer medium, such as zinc oxide. An alternate method comprises applying the porous polymer film without plasma treatment and heat curing the film to form a proper bond.