Publication detail

Influence of heating direction on BGA solder balls structure

OTÁHAL, A. SOMER, J. SZENDIUCH, I.

Original Title

Influence of heating direction on BGA solder balls structure

English Title

Influence of heating direction on BGA solder balls structure

Type

conference paper

Language

en

Original Abstract

The soldering of BGA packages is well known process. Despite the increasing complexity of PCBs and diversity of BGA package footprints, further optimization and improvement of soldering is required. In this paper, the influence of heat flow direction during reflow soldering on the structure of ball joint was described. The SAC305 solder alloy was used for ball joint investigation under the no-clean solder flux condition. Tested samples were made from FR4 material with ENIG as a surface finish. The heating was generated by infrared heaters placed on the top, bottom and both sides of the sample. The substantial part of this work was focused on the characterization the solder joint structure with the respect to the intermetallic compounds formation. SEM and optical microscope images of cross-sectioned solder joints were used to characterize the quality of the boundary formation. Shear test method was used to evaluate the impact of intermetallic layer and inner solder joint structure on the mechanical properties of joints. This research helps to determine the influence of the direction of heat flux, i.e. direction of heating of the infrared heater used in the reflow soldering, for the formation of the solder ball joint on BGA package (primarily for rework).

English abstract

The soldering of BGA packages is well known process. Despite the increasing complexity of PCBs and diversity of BGA package footprints, further optimization and improvement of soldering is required. In this paper, the influence of heat flow direction during reflow soldering on the structure of ball joint was described. The SAC305 solder alloy was used for ball joint investigation under the no-clean solder flux condition. Tested samples were made from FR4 material with ENIG as a surface finish. The heating was generated by infrared heaters placed on the top, bottom and both sides of the sample. The substantial part of this work was focused on the characterization the solder joint structure with the respect to the intermetallic compounds formation. SEM and optical microscope images of cross-sectioned solder joints were used to characterize the quality of the boundary formation. Shear test method was used to evaluate the impact of intermetallic layer and inner solder joint structure on the mechanical properties of joints. This research helps to determine the influence of the direction of heat flux, i.e. direction of heating of the infrared heater used in the reflow soldering, for the formation of the solder ball joint on BGA package (primarily for rework).

Keywords

BGA package, reflow soldering, solder joint structure, intermetallic compounds

Released

26.04.2018

ISBN

978-0-9568086-4-6

Book

Microelectronics and Packaging Conference (EMPC) & Exhibition, 2017 21st European

Pages from

1

Pages to

4

Pages count

4

URL

BibTex


@inproceedings{BUT147119,
  author="Alexandr {Otáhal} and Jakub {Somer} and Ivan {Szendiuch}",
  title="Influence of heating direction on BGA solder balls structure",
  annote="The soldering of BGA packages is well known process. Despite the increasing complexity of PCBs and diversity of BGA package footprints, further optimization and improvement of soldering is required. In this paper, the influence of heat flow direction during reflow soldering on the structure of ball joint was described. The SAC305 solder alloy was used for ball joint investigation under the no-clean solder flux condition. Tested samples were made from FR4 material with ENIG as a surface finish. The heating was generated by infrared heaters placed on the top, bottom and both sides of the sample. The substantial part of this work was focused on the characterization the solder joint structure with the respect to the intermetallic compounds formation. SEM and optical microscope images of cross-sectioned solder joints were used to characterize the quality of the boundary formation. Shear test method was used to evaluate the impact of intermetallic layer and inner solder joint structure on the mechanical properties of joints. This research helps to determine the influence of the direction of heat flux, i.e. direction of heating of the infrared heater used in the reflow soldering, for the formation of the solder ball joint on BGA package (primarily for rework).",
  booktitle="Microelectronics and Packaging Conference (EMPC) & Exhibition, 2017 21st European",
  chapter="147119",
  doi="10.23919/EMPC.2017.8346878",
  howpublished="online",
  year="2018",
  month="april",
  pages="1--4",
  type="conference paper"
}