In a message dated 12/22/98 11:28:25 AM US Eastern Standard Time,
[log in to unmask] writes:

> -STD-001B Cleaning Options:
>
>  Paragraph 8.3.2 has a default cleanliness designator of C-22 which is
>  cleaning both sides of the assembly (the first 2) and performing tests for
>  Ionic residues per 8.3.6 and/or 8.3.7 (the second 2).

Correct.

>
>  In addition, paragraph 8.3.5 Flux Residues states "Assemblies shall be
>  tested in accordance with IPC-TM-650, Test Method 2.3.7 and shall comply
>  with the following requirements..."
>
>  Does this mean that on a Class 3 program, with a designator of C-22 (which
>  does not require test method 2.3.7), that test method 2.3.7 must still be
>  performed based on the "shall" requirement of 8.3.5, OR that 8.3.5 does not
>  apply because it is not part of the C-22 designator?

The way I read it, the answer is no.  If you had to do cleaning, ionic
cleanliness testing, *and* cleanliness by method 2.3.27, th cleanliness
designator would be C-221.  If you had to prove cleanliness by the above three
tests, plus SIR testing, the designator would be C-2213, etc.  So, I believe
that a designator of C-22 means that you do not have to do that additional
testing.  Of course, if your customer wants to see that data, the designator
is open to negotiation.

Method 2.3.27 is residual rosin by UV-Vis spectroscopy.  It has meaning for
high solids rosin fluxes, but is next to meaningless for water solubles and
low solids fluxes, due to the low amount of rosin in both types of fluxes.
The limits listed in para 8.3.5 were taken from the IPC Phase 1,2,3
Cleanliness study, which was based on high solids RA flux.  Due to the manual
agitation, this test method also has a fair amount of variability to it.  If
you **really* want a quantitative measure of residual rosin, have the
assemblies tested to method 2.3.27.1, which is high pressure liquid
chromatography (HPLC).  Much more accurate.

The J-STD-001 Handbook, chapter 8 goes into all of this in greater detail.

>
>  Thanks in advance.

Hope this helps.

Doug Pauls
Technical Director
CSL

################################################################
TechNet E-Mail Forum 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's web site (http://www.ipc.org) "On-Line Services" section for additional information.
For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312
################################################################