Jeff,
Thanks for the help (and ribbing!)
This is our qualification run!! We are running 3 types of solder, and so far
the first two are doing it. We did not consult IPC for paste test
parameters, but we in the process of making sure we have the necessary
documents to satisfy QC.
I did get a temp/humidity recorder back in June and have had it running
since July. Neither temp or humidity shows any siginificant variations over
any 24 hour or weekly comparison.
Any other thoughts? And thanks again.
Richard Hamilton
Clemar Mfg. / Rain Bird
[log in to unmask]
> -----Original Message-----
> From: Jeff Hempton [SMTP:[log in to unmask]]
> Sent: Friday, August 21, 1998 11:54 AM
> To: [log in to unmask]
> Subject: [TN] Paste Printing
>
> Richard,
> I ran into this in a previous life, and it drove me crazy for a
> couple of weeks.
> A couple of quick points & things to check:
> Before you blame the paste, check:
> - the humidity, if too dry, this could cause a problem. I had one
> paste which would show problems every fall ,surprisingly it was the
> same time the plant furnaces were fired-up and we had drier air! Also
> check the temp/humidity inside the screen printer at the paste
> location. I also had an instance where fans that normally helped keep
> heat out of the printer quit working, and the area was hotter then
> norm.
> - If old metal blades, get new ones! they may not be releasing well.
>
> Now I would recommend getting your supplier involved immediately, and
> ask for some paste from another lot pronto...I have had unexplainably
> bad lots before.
> Also, obviously, dig deep to find any process changes from the
> norm...operators leaving it out of the fridge 4 days, bulk storage
> refrigerator at correct temp, etc....and since you mentioned you were
> new at this, this is NOT the norm. Most good pastes out there have
> excellent drop-off characteristics. Again, the key is to get your
> supplier involved ASAP.
> Oh, and are these results different then when you qualified your
> vendor/paste? You DID qualify your paste for your process, using IPC
> tests, didn't you? If not, now you know why we run all of those
> preliminary tests to choose a paste!
> (Just some friendly Friday ribbing %^)
> Good Luck.
> United Technology Electronic Controls
> Jeff L. Hempton, Sr. SMD Engineer
> 3650 West 200 North
> Huntington, In
> 46750-9002
> E-mail: [log in to unmask]
>
>
>
> ______________________________ Forward Header
> __________________________________
> Subject: [TN] Paste Printing
> Author: "Hamilton; Richard -4454" <[log in to unmask]> at Internet
> Date: 8/21/98 10:30 AM
>
>
> Hello to all,
>
> Well we are finally testing our SM capabilities, we are brand new at this.
> We have an issue at paste printing that I would like everyone's input on.
>
> When the squeege makes it's pass on the stencil and then lifts upward off
> the stencil, the majority of the paste remains with the squeege instead of
> on the stencil.
>
> What factors are there in the paste charactistics when applied?
>
> Thank you all in advance.
>
> Richard Hamilton
> Clemar Mfg. / Rain Bird
> [log in to unmask]
>
> ################################################################
> 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
> ################################################################
>
> ################################################################
> 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
> ################################################################
################################################################
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
################################################################
################################################################
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
################################################################
|
