Mr. Chee,

     Concerning preheating, recommendations are to measure 107'C. in RSS
     side or 120'C in WSS side prior entrance in the wave solder pot. This
     is to minimize SMT WSS component crack due to "delta t" temperature
     gradient and to have flux activation without having pcb wet. In this
     conditions, you should have minimum residue formation.

     Concerning running non-stop wave solder, you should consider that stop
     function bewteen boards will reduce dross formation but increase
     concern in controlling wave heigth precision. So in my case I work
     with continous pumping and I do a periodical machine de-dross cleaning


______________________________ Reply Separator _________________________________
Subject: [TN] To On or Not to On -Reply
Author:  "TechNet E-Mail Forum." <[log in to unmask]>, at CCGATE
Date:    16/2/98 8:20


Mr. Chee

Please advice the tech. to present a rose to the prod. supervisor.
It is not a good idea to argue with a lady in a work place.  Men
usually lose out at the end regardless of who wins.  This doesn't
mean she is right.  Tell the tech. ( when you are alone with him)
keep the preheat temp at 120'c and leave the sensor on (or
increase the sensor on time to prevent some miss-outs)

regards
Matthew
NII

>>> Hew How Chee <[log in to unmask]> February
13, 1998  7:23 pm >>>
Hello,

Can anybody please help or advice.

I am trying to settle a dispute between my company's production
supervisor and the maintenance technician on the wave
soldering
machine.

1) The maintenance technician insisted that the wave should be
switched
on and off between boards to prevent/lessen "damage" to the
wave
creation mechanism.
(The wave can be switched on and off automatically by a sensor
on the
conveyor). My production supervisor think otherwise. She
covered the
sensor so that the wave would not be off.(She says the sensor
can
miss a board) So, who is right ?

2) My production supervisor sets the preheat to about 95 degree
C so
that
the flux would not dry up when the PCB board reaches the wave
and to
increase
solderability.(but this created a lotof residue on the solder
bath,according to maintenance).
My maintenance technician says the temperature should be
about 120
degree C
so that it dry up the flux before the board reaches the wave. The
reason
is so that
not much residue is created. Who is right again ??

Thanks in advance.

How Chee
Malaysia

################################################################
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 web site (http://jefry.ipc.org/forum.htm) for
additional information.
For the technical support contact Dmitriy Sklyar at
[log in to unmask] or 847-509-9700 ext.311
################################################################

################################################################
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 web site (http://jefry.ipc.org/forum.htm) for additional
information.
For the technical support contact Dmitriy Sklyar at [log in to unmask] or
847-509-9700 ext.311
################################################################

################################################################
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 web site (http://jefry.ipc.org/forum.htm) for additional information.
For the technical support contact Dmitriy Sklyar at [log in to unmask] or 847-509-9700 ext.311
################################################################