In a message dated 06/05/2000 8:41:37 AM US Eastern Standard Time,
[log in to unmask] writes:
>
> I understand using clean process, ionic contamination is one of
> the way of measuring the residue, however, it is mainly for clean
> process.
If you are looking to quantify residues, you have two choices: chemical
characterization or electrical characterization. Chemical characterization
includes things like IC, FT-IR, GC-MS, etc. Electrical characterization
includes things like SIR or burn-in testing.
If you do chemical characterization, you have two choices: extraction or
in-situ (in-place) based tests. A common in-situ test if surface reflectance
microscopy Fourier Transform Infrared spectroscopy which is useful in
measuring organic composition. If you do extraction-based testing, there are
a wide range of extract tests, such as FT-IR, IC, ROSE, atomic absorption,
etc. In extraction based testing, you must select an appropriate solvent to
dissolve the residues of interest; an appropriate extraction temperature, and
an appropriate extraction temperature.
It all depends on what you are looking for. If you are looking, as you
indicate, the amount of low solids flux residue remaining after wave
soldering, I would recommend ion chromatography using IPC-TM-650, method
2.3.28. The amount of flux applied is usually directly proportional to the
amount of weak organic acid activator remaining. Residual rosin can be
examined using the same extract solution using HPLC per IPC-TM-650, method
2.3.27.1.
Doug Pauls
CSL
##############################################################
TechNet Mail List provided as a free service by IPC using LISTSERV 1.8c
##############################################################
To subscribe/unsubscribe, send a message to [log in to unmask] with following text in
the body:
To subscribe: SUBSCRIBE TECHNET <your full name>
To unsubscribe: SIGNOFF TECHNET
##############################################################
Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional
information.
If you need assistance - contact Keach Sasamori at [log in to unmask] or
847-509-9700 ext.5315
##############################################################
|
