Details
| Original language | English |
|---|---|
| Title of host publication | 7th International Conference on Thermal, Mechanical and Multiphysics Simulation and Experiments in Micro-Electronics and Micro-Systems, EuroSimE 2006 |
| Publication status | Published - 2006 |
| Event | 7th International Conference on Thermal, Mechanical and Multiphysics Simulation and Experiments in Micro-Electronics and Micro-Systems, EuroSimE 2006 - Como, Italy Duration: 24 Apr 2006 → 26 Apr 2006 |
Publication series
| Name | 7th International Conference on Thermal, Mechanical and Multiphysics Simulation and Experiments in Micro-Electronics and Micro-Systems, EuroSimE 2006 |
|---|---|
| Volume | 2006 |
Abstract
Studies made by PCB material suppliers concerning the behaviour of PCB towards moisture are mainly done on "raw" material. They don't take into account the presence and repartition of other materials for instance conductive layers. To get knowledge of the behaviour of the actual PCB's with humidity, different measurements were carried out. The desorption during baking at temperatures from 80° to 120°C, the absorption curves in ambient air (23°C/45%RH), as well as in dry pack storage conditions, and forced absorption under controlled atmosphere (85°C/85%RH) were measured. The absorption and the adsorption were determined by weighting. The saturation concentration at 85%RH/85°C for pure FR4 samples was 11,600 ppm. The moisture ingress depends on the internal track repartition, and thus cannot be directly assessed by measurements. The use of FE-simulations can give information about the moisture distribution in the structures. Under the assumption that the uptake of humidity and the desorption, in composites follow more or less a Pick's law, the measured diffusivities were used as input parameters for FE-simulations. A very good agreement between measurement and simulation for absorption as well as desorption was found for the different temperatures. From the FE-simulations it was found that 8 hours of baking to achieve a dryness of 800 ppm at T=120°C are only sufficient for pure FR4. For samples with copper layers, the baking must be longer. This result proves that copper layers act as blocking planes regarding moisture absorption or desorption. Delamination risks are also investigated. With this simplified model, an easy and fast determination of the diffusion process in actual PCB's, including the conductive layers, is possible.
ASJC Scopus subject areas
- Engineering(all)
- General Engineering
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7th International Conference on Thermal, Mechanical and Multiphysics Simulation and Experiments in Micro-Electronics and Micro-Systems, EuroSimE 2006. 2006. 1643964 (7th International Conference on Thermal, Mechanical and Multiphysics Simulation and Experiments in Micro-Electronics and Micro-Systems, EuroSimE 2006; Vol. 2006).
Research output: Chapter in book/report/conference proceeding › Conference contribution › Research › peer review
}
TY - GEN
T1 - Measurements and FE-simulations of moisture distribution in FR4 based printed circuit boards
AU - Frémont, Hélène
AU - Horaud, Walter
AU - Weide-Zaage, Kirsten
N1 - Copyright: Copyright 2011 Elsevier B.V., All rights reserved.
PY - 2006
Y1 - 2006
N2 - Studies made by PCB material suppliers concerning the behaviour of PCB towards moisture are mainly done on "raw" material. They don't take into account the presence and repartition of other materials for instance conductive layers. To get knowledge of the behaviour of the actual PCB's with humidity, different measurements were carried out. The desorption during baking at temperatures from 80° to 120°C, the absorption curves in ambient air (23°C/45%RH), as well as in dry pack storage conditions, and forced absorption under controlled atmosphere (85°C/85%RH) were measured. The absorption and the adsorption were determined by weighting. The saturation concentration at 85%RH/85°C for pure FR4 samples was 11,600 ppm. The moisture ingress depends on the internal track repartition, and thus cannot be directly assessed by measurements. The use of FE-simulations can give information about the moisture distribution in the structures. Under the assumption that the uptake of humidity and the desorption, in composites follow more or less a Pick's law, the measured diffusivities were used as input parameters for FE-simulations. A very good agreement between measurement and simulation for absorption as well as desorption was found for the different temperatures. From the FE-simulations it was found that 8 hours of baking to achieve a dryness of 800 ppm at T=120°C are only sufficient for pure FR4. For samples with copper layers, the baking must be longer. This result proves that copper layers act as blocking planes regarding moisture absorption or desorption. Delamination risks are also investigated. With this simplified model, an easy and fast determination of the diffusion process in actual PCB's, including the conductive layers, is possible.
AB - Studies made by PCB material suppliers concerning the behaviour of PCB towards moisture are mainly done on "raw" material. They don't take into account the presence and repartition of other materials for instance conductive layers. To get knowledge of the behaviour of the actual PCB's with humidity, different measurements were carried out. The desorption during baking at temperatures from 80° to 120°C, the absorption curves in ambient air (23°C/45%RH), as well as in dry pack storage conditions, and forced absorption under controlled atmosphere (85°C/85%RH) were measured. The absorption and the adsorption were determined by weighting. The saturation concentration at 85%RH/85°C for pure FR4 samples was 11,600 ppm. The moisture ingress depends on the internal track repartition, and thus cannot be directly assessed by measurements. The use of FE-simulations can give information about the moisture distribution in the structures. Under the assumption that the uptake of humidity and the desorption, in composites follow more or less a Pick's law, the measured diffusivities were used as input parameters for FE-simulations. A very good agreement between measurement and simulation for absorption as well as desorption was found for the different temperatures. From the FE-simulations it was found that 8 hours of baking to achieve a dryness of 800 ppm at T=120°C are only sufficient for pure FR4. For samples with copper layers, the baking must be longer. This result proves that copper layers act as blocking planes regarding moisture absorption or desorption. Delamination risks are also investigated. With this simplified model, an easy and fast determination of the diffusion process in actual PCB's, including the conductive layers, is possible.
UR - http://www.scopus.com/inward/record.url?scp=33847164139&partnerID=8YFLogxK
U2 - 10.1109/ESIME.2006.1643964
DO - 10.1109/ESIME.2006.1643964
M3 - Conference contribution
AN - SCOPUS:33847164139
SN - 1424402751
SN - 9781424402755
T3 - 7th International Conference on Thermal, Mechanical and Multiphysics Simulation and Experiments in Micro-Electronics and Micro-Systems, EuroSimE 2006
BT - 7th International Conference on Thermal, Mechanical and Multiphysics Simulation and Experiments in Micro-Electronics and Micro-Systems, EuroSimE 2006
T2 - 7th International Conference on Thermal, Mechanical and Multiphysics Simulation and Experiments in Micro-Electronics and Micro-Systems, EuroSimE 2006
Y2 - 24 April 2006 through 26 April 2006
ER -