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Method for a universal daisy chain design concept

IP.com Disclosure Number: IPCOM000008386D
Publication Date: 2002-Jun-11
Document File: 3 page(s) / 116K

Publishing Venue

The IP.com Prior Art Database

Abstract

Disclosed is a method for a universal daisy chain (UDC) design concept. Benefits include improved test environment and improved reliability.

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Method for a universal daisy chain design concept

Disclosed is a method for a universal daisy chain (UDC) design concept. Benefits include improved test environment and improved reliability.

Background

              Products with different ball patterns require a daisy chain unit for level-2 interconnect integrity and test contact characterization/qualification.

              The conventional method is to design a specific daisy chain unit for every product for acceptance/test readiness and mechanical model validation.

General description

              The disclosed method is a single daisy-chain test vehicle that supports multiple ball patterns, driven by product needs. The key elements include:

·        Routing concept that enables multiple depopulation without losing electrical testing capability

·        Different ball patterns using solder ball masking

·        Boundary conditions that define the scope of UDC

Advantages

              The disclosed method provides advantages, including:

·        Cost avoidance of multiple daisy chain units with tooling costs

·        Elimination of design cycles for multiple designs, saving resources, time, and subsequent development cycles

Detailed description

              The disclosed method is a daisy chain unit that is a mechanical test vehicle. The method enables the following:

·        Solder-joint reliability characterizations

·        Model validation

·        Test-module collaterals qualification

·        New product introduction (NPI) readiness in assembly process

              Ball grid array (BGA) fields come with various ball patterns, ranging from fully populated pure square matrix to face center square. Ball pattern depopulation depends on product requirements. The goal of o...