Browse Prior Art Database

Method for a package assembly with PSIP

IP.com Disclosure Number: IPCOM000074608D
Publication Date: 2005-Feb-23
Document File: 3 page(s) / 74K

Publishing Venue

The IP.com Prior Art Database

Abstract

Disclosed is a method for a package assembly with PSIP. Benefits include improved functionality.

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Method for a package assembly with PSIP

Disclosed is a method for a package assembly with PSIP. Benefits include improved functionality.

Background

              Conventionally, a PSIP is mounted on the substrate beside the first die in the stacked package. Mounting a power supply in a package (PSIP) on the substrate increases the package size. The increase in the footprint is typically 2 mm (see Figure 1).

General description

      The disclosed method mounts the PSIP on the backside of the first die of the die stack and through the cut out on the substrate. As a result, the package footprint is not increased.

              The key elements of the disclosed method include:

•             Substrate with a central cutout

•             Passives mounted on backside of a die through the substrate cutout

Advantages

              The disclosed method provides advantages, including:
•             Improved functionality due to maintaining the conventional package size with an added PSIP

Detailed description

      The disclosed method places a PSIP in a cut out in a substrate. As a result, height relief is obtained equal to the substrate thickness (typically 0.21 to 0.24 mm). The PSIP is exposed on the underside of the substrate. However, calculations indicate that the exposed portion is less than the post-reflow solder ball height of 0.19 mm (see Figure 2).

              The disclosed method does not use any technology that is available conventionally. Passive devices can be attached to the back side of the die, which can be attached to th...