Browse Prior Art Database

Panel Edges with an Identical Substrate Design to Reduce Substrate Warpage

IP.com Disclosure Number: IPCOM000083157D
Publication Date: 2005-Mar-01
Document File: 3 page(s) / 38K

Publishing Venue

The IP.com Prior Art Database

Abstract

Disclosed is a method that uses identical designs at the substrate panel edges to reduce the internal stress acting on the individual substrates in the panel. Benefits include reducing substrate warpage, and reducing the cost of scrapping test-good units.

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 69% of the total text.

Panel Edges with an Identical Substrate Design to Reduce Substrate Warpage

Disclosed is a method that uses identical designs at the substrate panel edges to reduce the internal stress acting on the individual substrates in the panel. Benefits include reducing substrate warpage, and reducing the cost of scrapping test-good units.

Background

Currently, there are high substrate co-planarity fallout issues associated with the assembly process; this results in the high cost of scrapping test-good units. To reduce substrate warpage, operator or machine handling methods are improved on the substrate panel. In addition, extra thermal treatment processes (e.g. using a stiffer core for the substrate panel) are used to reduce the internal stresses on the panel (see Figure 1); however, these approaches neglect the impact to co-planarity from the internal stress caused by the substrate panel lay-up design.

General Description

Stress concentrations at the edges of the substrate are due to a difference in the coefficient of thermal expansion (CTE) between the dummy area and the actual substrates; this results in a high stress concentration on the panel corners and edges. In the disclosed method,  there is an identical substrate pattern at the edge, so the dummy area shares the same CTE as the actual substrates; therefore, the substrate at the corners and edges do not have a significant difference in CTE.

During the substrate SAP process, a new glass mask is applied that has an identical s...