Title :
Observation of copper ionic migration in insulation layer by pulsed electroacoustic method [metal-base PWBs]
Author :
Okamoto, Kenji ; Fukunaga, Kaori ; Maeno, Takashi ; Tsukui, Tsutomu
Author_Institution :
Fuji Electr. Corp. R&D Ltd., Yokosuka, Japan
fDate :
6/1/2002 12:00:00 AM
Abstract :
We have studied the behavior of ionic impurities in the insulation layer of metal-base PWBs and carried out nondestructive detection of copper ionic migration using the pulsed electroacoustic method for measuring the space charge. Space charge polarization was observed initially and after pre-absorption under high-temperature, high-humidity conditions. It appears to be attributable to the ions present initially in the insulation layer. The space charge measurement detected a conductive region formed in the insulation layer near the anode after bias testing under high-temperature, high-humidity conditions (THB test). Element distribution analysis verified, it as a region of copper ionic migration. Growth of copper ionic migration in the insulation layer was detected nondestructively
Keywords :
charge measurement; copper; environmental testing; impurities; insulating thin films; printed circuit testing; space charge; Cu; Cu ionic migration; THB test; bias testing; conductive region formed; element distribution analysis; high-humidity conditions; high-temperature conditions; insulation layer; ionic impurities; metal-base PWBs; nondestructive detection; pulsed electroacoustic method; space charge measurement; space charge polarization; Charge measurement; Conductivity measurement; Copper; Current measurement; Impurities; Insulation testing; Polarization; Pulse measurements; Pulsed electroacoustic methods; Space charge;
Journal_Title :
Components and Packaging Technologies, IEEE Transactions on
DOI :
10.1109/TCAPT.2002.1010012
