Dear All,
Thanks for that all of you give me so many kind advices.
One more thing to trouble you, could you please recommend me which agency
can perform SIR test and provide independent test report ?
Best regards
Charles Lee
-----Original Message-----
From: TGAsia [mailto:[log in to unmask]] On Behalf Of Christine Poon Lai Peng
Sent: Saturday, September 27, 2008 3:41 PM
To: [log in to unmask]
Subject: Re: [TGAsia] 转发:The effec t of Flux r esi du e on PCB
Charles:
Peter is correct on SIR data of the flux. You can also check the J-STD-004A
category of the flux example ROL0 or ORM1, which gives you a better idea of
the chemistry and amount/type of activators that the flux contains.
Most important is to identify the root cause, whether flux residue alone
cause the current leakage issue or combination of flex residue + solder mask
etc.
Thanks everyone for your kind words on Kester fluxes.
Best regards,
Christine Poon
-----Original Message-----
From: TGAsia [mailto:[log in to unmask]] On Behalf Of peter gong
Sent: Friday, September 26, 2008 10:12 PM
To: [log in to unmask]
Subject: Re: [TGAsia] 转发: The effec t of Flux r esidu e on PCB
Charles,
I dont know what is your detailed process and your suppliers for both solder
paste and soldermask supplier but still have some suggestions below:
1. please let your suppliers to check the SIR test performance data and flux
component especially for activator. Normally organic acid should be paid
more attention.
2.please cowork with your supplier from PCB soldermask, their so many data
will help you understand more about this issue. there are so many
requirement for solder mask.
3.Try to fine tune your temp profile using longer soak time to reduce the
reactivtors.
Of course, you can try kester product, I like their products very much!
Good luck!
2008/9/26 Santoso, Suprapto <[log in to unmask]>
Try one of the Kester product (Flux 979) for better SIR test
performance. Maybe cost you more but solves your problem.
SUPRAPTO SANTOSO
________________________________
From: NG ENG GUAN [mailto:[log in to unmask]]
Sent: Friday, September 26, 2008 4:33 PM
To: [log in to unmask]
Subject: Re: [TGAsia] 转发: The effect of Flux residu e on PCB
Hi Leo,
No doubt , this is caused by the flux. We had faced the same problem
before .Our solution is to clean up the flux.
From: TGAsia [mailto:[log in to unmask]] On Behalf Of Leo Yang
Sent: 26 September 2008 13:03
To: [log in to unmask]
Subject: [TGAsia] 转发: The effect of Flux residue on PCB
Importance: High
FYI
B/R
Leo Yang
IPC WOFE
21-54973435-616
________________________________
From: charles.lee [mailto:[log in to unmask]]
Sent: Friday, September 26, 2008 11:51 AM
To: 'Asia Committe Task Group Forum'
Subject: The effect of Flux residue on PCB
Dear All,
Our customer complained us that flux residue resulted in dielectric
resistance reduction between two pads on PCB (From 10Mohm to 3Kohm), please
refer to the attached picture.
The flux we have been using is No-clean type supplied by Union
Soltek.
We are now puzzled with below questions:
1) What is the chemical substance around these two pads? Is it
only flux residue?
2) Will the flux residue be able to occur chemical reaction
with solder mask after elapse of a long time?
3) What is the root cause which results in dielecric
resistance variance?
We look forward to your expertised explaination, thanks!
Best reagrds
Charles Lee
--
Best Regards
龔岳曦
*Peter Gong*
cellular phone:China 13417366601
MSN: [log in to unmask] <mailto:[log in to unmask]>_
_ [log in to unmask] <mailto:[log in to unmask]>
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