Journal article
Experimental Study of Moisture Ingress in First and Second Levels of Electronic Housings
Moisture uptake of polymer materials used for electronic packaging and moisture ingress into automotive electronic sensor housings have been studied by exposure to constant and cyclic humidity and temperature conditions. The first-level housing is made of epoxy molding compound (EMC) and encapsulates the sensor silicon-chip.
The second-level housing is made of polybutylene terephthalate and contains the EMC attached to a printed circuit board (PCB). The novel approach was to perform in situ measurements of the temperature and the relative humidity (RH) inside the EMC next to the silicon chip, and to measure the humidity transfer from outdoor to the second, and through the first-level housings up to the chip.
The effect of the presence of PCB and the self-heating of components have been investigated. The results showed that the time constants for humidity to reach 63% of outdoor conditions are about 2 and 7 days at 60 degrees C for the second-and first-level housings, respectively. Exposure to cyclic conditions showed that the internal RH tends to reach a steady state, close to the mean value of the cyclic outdoor profile, while the presence of polymeric materials (as PCB) can act as a humidity buffer and absorb and desorb water when subjected to temperature fluctuations.
Language: | English |
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Publisher: | IEEE |
Year: | 2018 |
Pages: | 1928-1937 |
ISSN: | 21563950 and 21563985 |
Types: | Journal article |
DOI: | 10.1109/TCPMT.2018.2799233 |
ORCIDs: | Ambat, Rajan |
Epoxy molding compound (EMC) Housings Humidity Moisture diffusion Printed circuit board (PCB) Temperature
EMC Electromagnetic compatibility Moisture PCB Packaging Polymers Reliability Temperature measurement automotive electronic sensor housings automotive electronics constant humidity cyclic conditions cyclic humidity cyclic outdoor profile electronic housings electronic packaging electronics packaging encapsulation epoxy molding compound experimental study first-level housing first-level housings housings humidity humidity buffer humidity transfer moisture moisture diffusion moisture ingress moisture uptake moulding polymeric materials polymers printed circuit board printed circuit board (PCB) printed circuit manufacture relative humidity second- level housings second-level housing sensor silicon-chip silicon silicon chip temperature temperature conditions time constants