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Reliability of ACA interconnections on microvia HDI PCBs in thermal cycling conditions

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review


Original languageEnglish
Title of host publicationIMAPS Nordic Annual Conference 2016 Proceedings
Editors J. Kutilainen
PublisherIMAPS-International Microelectronics and Packaging Society
ISBN (Electronic)9781510827226
Publication statusPublished - 5 Jun 2016
Publication typeA4 Article in a conference publication
EventIMAPS Nordic Annual Conference - Tonsberg, Norway
Duration: 5 Jun 20167 Jun 2016


ConferenceIMAPS Nordic Annual Conference


New packaging technologies require new high density substrates. In built up high density interconnect (HDI) printed circuit boards (PCB) high density is achieved by using built up microvia layers. Such HDI PCBs may be used in many applications. In flip chip technology a bare chip is attached directly to a substrate which enables very high density and requires often also HDI PCBs. Anisotropic conductive adhesives (ACA) are especially well suited interconnection materials for high density flip chip applications. In this study the reliability of flip chip ACA attachments on several different HDI PCBs was studied. The PCBs had similar core layers, but the microvia layers of the PCBs were different. Test chips were attached on these PCBs using an ACA film (ACF). The reliability of the interconnections was tested using fast thermal cycling between the temperatures of -40?C and 125?C. Several failures were seen with all PCB materials during the 2,000 cycles of testing. The differences in the reliability of the different microvia layers were found to be relatively small and the microvia layer composition did not seem to be critical for the thermal cycling reliability of the ACF interconnections.


  • Anisotropic conductive adhesive, Flip chip, High density interconnect, Printed circuit board, Reliability, Thermal cycling

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