Details
| Original language | English |
|---|---|
| Title of host publication | 2016 Pan Pacific Microelectronics Symposium, Pan Pacific 2016 |
| Publisher | Institute of Electrical and Electronics Engineers Inc. |
| ISBN (electronic) | 9780988887398 |
| Publication status | Published - 7 Mar 2016 |
| Event | Pan Pacific Microelectronics Symposium, Pan Pacific 2016 - Big Island, United States Duration: 25 Jan 2016 → 28 Jan 2016 |
Abstract
For some applications like ship, aircraft and car, electronic systems are submitted to salt environment. In this case, the main reliability issue is the corrosion of the metals from the pads and the solder alloys. More than 20% of failures in microelectronic devices can be attributed to corrosion. Nevertheless this phenomenon is little studied on microelectronic assemblies. This paper presents ageing tests in salt spray chamber performed on BGA (Ball Grid Array) assemblies. The test vehicle is composed of BGA components with SnAgCu ball mounted on FR4 board. This BGA is a daisy chained component. So the electrical continuity of the assembly can be tested thanks to the electrical resistance measurement of the solder joint chain. The assemblies are put in a salt spray chamber at 35°C with 5% sodium chloride (NaCl) aqua according to the ASTM B117-09 standard, which is an accelerated test to stimulate the effects of a severe marine atmosphere on exposed surfaces. The assemblies are removed at 24, 48, 72 and 96 hours. The electrical resistance and the weight are measured during the test. The solder joints and the copper pads are observed and analysed with optical microscope. Then samples are cross-sectioned and polished to reveal the solder microstructure, in order to be examined by a scanning electron microscope (SEM) equipped with an energy-dispersive x-ray (EDX) system. The corrosion of some Cu pads is observed, in particular for the pads without solder alloy. The solder joint deterioration is visible but no electrical failure is detected. The microstructure is observed in order to determine the corroded residues found on the surface solder balls after the salt spray test. The Ag3Sn contained in SnAgCu solder joints seems to accelerate the corrosion of tin because of the galvanic corrosion mechanism.
Keywords
- BGA assembly, corrosion, lead-free solder, salt spray test
ASJC Scopus subject areas
- Engineering(all)
- Electrical and Electronic Engineering
- Materials Science(all)
- Electronic, Optical and Magnetic Materials
Sustainable Development Goals
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2016 Pan Pacific Microelectronics Symposium, Pan Pacific 2016. Institute of Electrical and Electronics Engineers Inc., 2016. 7428402.
Research output: Chapter in book/report/conference proceeding › Conference contribution › Research › peer review
}
TY - GEN
T1 - Corrosion study on BGA assemblies
AU - Guedon-Gracia, A.
AU - Fremont, H.
AU - Deletage, J. Y.
AU - Weide-Zaage, K.
N1 - Publisher Copyright: © 2016 SMTA. Copyright: Copyright 2017 Elsevier B.V., All rights reserved.
PY - 2016/3/7
Y1 - 2016/3/7
N2 - For some applications like ship, aircraft and car, electronic systems are submitted to salt environment. In this case, the main reliability issue is the corrosion of the metals from the pads and the solder alloys. More than 20% of failures in microelectronic devices can be attributed to corrosion. Nevertheless this phenomenon is little studied on microelectronic assemblies. This paper presents ageing tests in salt spray chamber performed on BGA (Ball Grid Array) assemblies. The test vehicle is composed of BGA components with SnAgCu ball mounted on FR4 board. This BGA is a daisy chained component. So the electrical continuity of the assembly can be tested thanks to the electrical resistance measurement of the solder joint chain. The assemblies are put in a salt spray chamber at 35°C with 5% sodium chloride (NaCl) aqua according to the ASTM B117-09 standard, which is an accelerated test to stimulate the effects of a severe marine atmosphere on exposed surfaces. The assemblies are removed at 24, 48, 72 and 96 hours. The electrical resistance and the weight are measured during the test. The solder joints and the copper pads are observed and analysed with optical microscope. Then samples are cross-sectioned and polished to reveal the solder microstructure, in order to be examined by a scanning electron microscope (SEM) equipped with an energy-dispersive x-ray (EDX) system. The corrosion of some Cu pads is observed, in particular for the pads without solder alloy. The solder joint deterioration is visible but no electrical failure is detected. The microstructure is observed in order to determine the corroded residues found on the surface solder balls after the salt spray test. The Ag3Sn contained in SnAgCu solder joints seems to accelerate the corrosion of tin because of the galvanic corrosion mechanism.
AB - For some applications like ship, aircraft and car, electronic systems are submitted to salt environment. In this case, the main reliability issue is the corrosion of the metals from the pads and the solder alloys. More than 20% of failures in microelectronic devices can be attributed to corrosion. Nevertheless this phenomenon is little studied on microelectronic assemblies. This paper presents ageing tests in salt spray chamber performed on BGA (Ball Grid Array) assemblies. The test vehicle is composed of BGA components with SnAgCu ball mounted on FR4 board. This BGA is a daisy chained component. So the electrical continuity of the assembly can be tested thanks to the electrical resistance measurement of the solder joint chain. The assemblies are put in a salt spray chamber at 35°C with 5% sodium chloride (NaCl) aqua according to the ASTM B117-09 standard, which is an accelerated test to stimulate the effects of a severe marine atmosphere on exposed surfaces. The assemblies are removed at 24, 48, 72 and 96 hours. The electrical resistance and the weight are measured during the test. The solder joints and the copper pads are observed and analysed with optical microscope. Then samples are cross-sectioned and polished to reveal the solder microstructure, in order to be examined by a scanning electron microscope (SEM) equipped with an energy-dispersive x-ray (EDX) system. The corrosion of some Cu pads is observed, in particular for the pads without solder alloy. The solder joint deterioration is visible but no electrical failure is detected. The microstructure is observed in order to determine the corroded residues found on the surface solder balls after the salt spray test. The Ag3Sn contained in SnAgCu solder joints seems to accelerate the corrosion of tin because of the galvanic corrosion mechanism.
KW - BGA assembly
KW - corrosion
KW - lead-free solder
KW - salt spray test
UR - http://www.scopus.com/inward/record.url?scp=84964988373&partnerID=8YFLogxK
U2 - 10.1109/panpacific.2016.7428402
DO - 10.1109/panpacific.2016.7428402
M3 - Conference contribution
AN - SCOPUS:84964988373
BT - 2016 Pan Pacific Microelectronics Symposium, Pan Pacific 2016
PB - Institute of Electrical and Electronics Engineers Inc.
T2 - Pan Pacific Microelectronics Symposium, Pan Pacific 2016
Y2 - 25 January 2016 through 28 January 2016
ER -