Browse Prior Art Database

Method for a package cavity and projection designs for stacked packages

IP.com Disclosure Number: IPCOM000008394D
Publication Date: 2002-Jun-11
Document File: 5 page(s) / 75K

Publishing Venue

The IP.com Prior Art Database

Abstract

Disclosed is a method for a package cavity and projection designs for stacked packages. Benefits include improved capability to meet customer requirements.

This text was extracted from a Microsoft Word document.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 50% of the total text.

Method for a package cavity and projection designs for stacked packages

Disclosed is a method for a package cavity and projection designs for stacked packages. Benefits include improved capability to meet customer requirements.

Background

              Conventionally, stacking packages involves gluing packages together with a layer of adhesive material. The adhesive increases the total thickness of the stacked packages by 25 to 50 µm for a 2-package stackup (see Figure 1) and by 50 to 100 µm for a 3-package stackup.

                 Reducing the standoff height is critical for applications such as cellular phones and hand held devices where the total stacked standoff height is targeted at 1 mm. The problem is addressed by trying to decrease the package thickness by decreasing the die thickness. Handling thin die is a process concern. The conventional technology trend is to increase the number of stacked packages to increase the functionality of the product. However, the total thickness of the stacked packages increases beyond the 1-mm target thickness that customers require.

General description

      The disclosed method supplements the thin-die strategy and is more effective as the number of stacked packages increases. A cavity design in one package and a corresponding projection design on the mating package is used to join or stack packages without increasing the total height of the stacked packages.

              For the stacking of molded packages, a cavity is made in the molding compound surface of one package and a corresponding projection is made on the mating surface of the stacked package. Adhesive is placed in the cavity region and used to join the two packages. The geometries of the cavity and the projection are designed so that a reservoir for the adhesive exi...