Hello William, When a visible staining or water marking is apparent on PCB¹s or PCBA¹s, the primary concern is the cleanliness of the Board. Dirty PCB¹s or PCBA¹s can provide an environment that will stimulate ElectroChemical migration and can cause product failure. You can test whether the staining is ionic in nature with basic ROSE type of Alcohol/DI water wash or you can test with Ion Chromatography to get details on the contaminates (if any) present. Best Regards, Bob Neves Chairman/CTO Microtek Laboratories [log in to unmask] www.TheTestLab.com Anaheim, CA +1 (714) 999-1616 Changzhou, China +86 (519) 8548-7805 On 1/20/09 7:10 PM, "William Yeoh" <[log in to unmask]> wrote: > Hi, > > If solder mask is having so called Stain/water mark, can we accept? If we > can¹t, why? > > Thank you! > > Best Regards, > William Yeoh > Aeroteq Solutions Sdn. Bhd. > mailto:[log in to unmask] <mailto:[log in to unmask]> > Tel#6-04-640-3665 > Fax#6-04-640-3666 > Hp#6-012-477-0720 > > Internet E-mail Confidentiality Disclaimer: This e-mail message may contain privileged or confidential information. If you are not the intended recipient, you may not disclose, use, disseminate, distribute, copy or rely upon this message or attachment in any way. If you received this e-mail in error, please return by forwarding the message and its attachments to the sender. Microtek Laboratories and its employees and agents do not accept liability for any errors, omissions, corruptions or virus in the contents of this message or any attachments.