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
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