Motorola Corporation

Bruce R Tegge

John K Frei

Howard D Knuth

A stepped via is formed in a circuit board. Large holes are punched in a predetermined pattern in two insulating sheets and small holes are punched in the same pattern in another insulating sheet. The holes are dimensioned so that their diameters are larger than the thicknesses of their respective sheets. However, the diameters of the larger holes are less than the combined thickness of all sheets. The sheets are juxtaposed so that the sheet with the smaller holes is between the other sheets and corresponding holes from the respective sheets are aligned. The sheets are pressed together to form an integral substrate. Metallization is applied from one side of the substrate, then metallization is applied to the substrate from the other side.

Circuit board having stepped vias

A semiconductor assembly which includes a carrier and a semiconductor die is mounted on a printed wiring board. The die includes a top active surface and a bottom active surface. The two active surfaces are non-coplanar. The carrier is made from layers of a ceramic material. Holes are formed through all but one of the layers. The layers are laminated into an integral substrate, and the substrate is fired. The holes form a cavity into but not through the substrate. The number of layers, lamination pressures, and firing parameters are all adjusted in response to the thickness of the die to insure that the height of cavity walls approximately equals the thickness of the die. Continuous metallization is applied in the cavity and on a top surface of the substrate. The die is bonded in the cavity, and conductive bumps are formed on the die and the metallization.

Leveled non-coplanar semiconductor die contacts

A package and a method of packaging semiconductor devices, especially in expanded wafer form. The package is formed by sticking an adhesive backed ring to the plastic sheet upon which the expanded wafer is affixed so that the ring surrounds the wafer. The adhesive backed ring holds the plastic sheet securely and protects the surface of the wafer. The package is completed by covering the wafer with a second protective sheet and vacuum sealing in a plastic bag.

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Scottsdale, AZ, United States of America

Bruce R Tegge