Direct chip attach circuit card
AssigneeInternational Business Machines Corporation
InventorsHormazdyar Minocher Dalal, Kenneth Michael Fallon
Life of this patent
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Abstract
A structure and a method is disclosed for making a laminated circuit carrier card for the purpose of making a Direct Chip Attached Module (DCAM) with low cost and high reliability. The carrier is made using an organic or an inorganic laminated carrier having at least one surface available for direct chip mount. The chip has at least one solder ball with a cap of low melting point metal. The surface of the carrier has electrical features that are directly connected to the low melting point metal on the solder ball of the chip to form the eutectic and this way the chip is directly attached to the carrier.
Claims27
An electronic card structure comprising a device carrier and at least one device electrically connected thereto by at least one solder ball, wherein said solder ball has a cap of at least one low melting point metal forming in combination with said solder ball a eutectic in assembly of said device carrier and said device, and wherein said low melting point metal caps between about 10 percent to about 90 percent of the exposed surface of said solder ball.
An electronic card structure comprising a device carrier and at least one device electrically connected thereto by at least one solder ball, wherein said solder ball has a cap of at least one low melting point metal forming in combination with said solder ball a eutectic in assembly of said device carrier and said device, and wherein said low melting point metal caps between about 10 percent to about 90 percent of the exposed surface of said solder ball and wherein said low melting point metal is selected from a group consisting of bismuth, indium, tin or alloys consisting of two or more of bismuth, indium, or tin.
An electronic structure comprising a substrate having at least one solder ball, wherein said solder ball has a cap of at least one low melting point metal, and wherein said low melting point metal caps between about 10 percent to about 90 percent of the exposed surface of said solder ball and wherein said low melting point metal is selected from a group consisting of bismuth, indium, tin or alloys consisting of two or more of bismuth, indium, or tin.
Dependencies are inferred from the claim text.