Process Manuals

Lead-Free Assembly Process Manual
Author: Michael Meilunas
Description:  This document provides material requirements, inspection guidelines and process recommendations for Pb-free area array assembly based upon our consortium sponsored research which covered a range of laminate and flex based BGAs and CSPs with pitches down to 0.5mm including Wafer Level CSPs (WL-CSPs). Much of the following is also relevant to other components such as ceramic BGAs and 0.4mm pitch WL-CSPs, except that the latter may be assembled without the use of solder paste. Very different considerations apply to flip chip and MLF/QFN/LGA assembly for which separate process guides are provided.
Assembly cannot be viewed independently of quality and reliability requirements and this document offers critical comments and recommendations pertaining to thermal cycle testing. 

Lead Free Thermal Cycling:
Accounting for the Dwell Time Dependence in Thermal Cycling of Lead Free Solder
Solder Joint Strain Evolution during Thermal Cycling
Thermal Cycle Reliability Assessment of Surface Mount Devices

Lead Free Isothermal Cycling Test Protocols and Recommendations:
Damage Accumulation in Pb-Free Solder Joints for Complex Loading Histories
Effects of Variable Amplitude Loading on Lead Free Solder Joint Properties and Damage Accumulation

Lead Free Rework and Repair:
AREA Consortium Rework Process Manual - Version 2014
Update Submitted by: Harry Schoeller
Added to this version:
  • Rework of Fine Pitch Components:
    • Rework and Re-ball process for 0.3mm CSP
    • Reliability of Reworked assemblies in ATC and drop testing
  • Vapor Phase Rework:
    • Description of VP desoldering fixture
    • VP desoldering procedure

Flip Chip Underfilling:
Flip Chip Underfill Process Manual

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