I am trying to source a system to clean misprinted PCB's from an SMT
manufacturing process. The system needs to have the capability to remove
both solder paste and (or) glue. It also needs to be able to cater for a
wide range of double sided PCB's which are already built on one side using a
No-Clean soldering process.

We are currently using a manual washing process which consists of a soft
brush which has a solvent is pumped through it ( Axarel 2200). The slovent
is circulated through a large filter and re-used. The boards are passed
through an Aqueous wash before going back into production.

Option 1 - Ultrasonic's
I have some concerns about the use of Ultrasonic's because we assemble a
wide variety of products for various customers ranging from RF devices to
P.C. motherboards and medical devices. I am nervous that the ultrasonic's
may cause damage to some of the components on the PCB of affect the overall
life-span and long term reliability of the product.
Q1. Are these concerns justified ?
Q2. Is there anyone else cleaning side 2 of PCB's which are already built on
side 1 using an ultrasonic system ?
Q3. Have there been any studies carried out on the effects of ultrasonics on
discrete components, IC's, Tantalum Capacitors, Diodes, Transistors or
Co-Axial Resonators ?

Option 2 - Spray Wash System
I have also been looking at what types of Industrial Spray cleaning systems
are available. Are spray washing systems effective for the removal of solder
paste and glue from via holes and plated through holes ? How successful is
this type of system for cleaning misprinted intrusive reflow PCB's. Most of
these systems use a water based cleaning agent in the washing cycle. This
cleaning agent then needs to be rinsed off the PCB's before the board can be
built through the rest of the process.
Q1. Is anyone out there familiar with this type of system ?
Q2. How is the rinse water treated / filtered before it goes to drain ?
Q3. Are there any problems with the cleaning agent contaminating the water
going to drain ?



Martin Bourke

##############################################################
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
##############################################################