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Crystalline Substances Coating for BGA Package Overheating Detection

IP.com Disclosure Number: IPCOM000028049D
Publication Date: 2004-Apr-21
Document File: 2 page(s) / 36K

Publishing Venue

The IP.com Prior Art Database

Abstract

Disclosed is a method that uses crystalline substances to detect package overheating; the crystalline substances change appearance when the package reaches or passes the maximum allowable temperature.

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Crystalline Substances Coating for BGA Package Overheating Detection

Disclosed is a method that uses crystalline substances to detect package overheating; the crystalline substances change appearance when the package reaches or passes the maximum allowable temperature.

Background

Electronic components are sensitive to maximum temperatures in the solder reflow process or rework process in motherboard manufacturing. High temperatures can significantly degrade the BGA package first-level interconnect, and can cause the BGA package to prematurely fail in a computer system. Additionally, the substrate of the BGA package can delaminate if overheated. These failure modes are well known, however a detection device for the BGA component does not exist for these conditions. This makes failure analysis difficult or impossible, making Intel liable for out-of-specifications conditions at the board manufacturing factory.

General Description

The disclosed method uses liquid crystals to detect any out-of-specification package processing, specifically due to overheating either during the in-line reflow soldering process or during rework. Liquid crystals have the qualities of crystalline solids and isotropic liquids: in different states they either flow like liquids or appear like solid crystals. Heating a crystal to a critical temperature changes the crystal from one structure to another. Changing the crystalline structure usually changes many physical properties of crystals, such as density...