Potential arcing as well for the carbon black left behind.  Excessive heating might induce delam (laser setting appear to be wrong).  You need to assessing the risk based on your application and design requirements.  My 2 cents.  

Joyce Koo
Materials Researcher - Materials Interconnect Lab
Research In Motion Limited
Office: (519) 888-7465 79945
Mobile: (226) 220-4760

-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of James Mahoney
Sent: Wednesday, June 20, 2012 7:18 AM
To: [log in to unmask]
Subject: Re: [TN] Type 3 flex burnt during laser cutting

Make sure you Plasma oxygen cycle after laser to clean the carbon (Blk). Some minor black is usually acceptable but need to be careful it can become conductive around ziff style connectors (High resistance). The more the acrylic adhesive the more the burnt black adhesive appears.

Thank you, Jim Mahoney 
Mass Design Inc.
Applications Engineer 
P# 603-886-6460 X215
DDTC Registered and ITAR Compliant 
ISO 9001:2008 Certified 
 Please consider the environment before printing this e-mail
Confidentiality Notice: This page and any accompanying documents contain information that is confidential, privileged or exempt from disclosure and is intended for the exclusive use of the addressee. If you are not the intended recipient, you are hereby notified that any disclosure, copying, distribution or use of the contents of this information in any manner is strictly prohibited.

-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Paul Edwards
Sent: Tuesday, June 19, 2012 5:30 PM
To: [log in to unmask]
Subject: Re: [TN] Type 3 flex burnt during laser cutting

Change to a different laser...

Paul

Paul Edwards

Process/Quality Engineering

Surface Art Engineering

-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of [log in to unmask]
Sent: Tuesday, June 19, 2012 1:33 PM
To: [log in to unmask]
Subject: [TN] Type 3 flex burnt during laser cutting

Need guideline for acceptance.

We have a Type 3 flex that requires laser cutting. (CO2 laser) Sometimes (very rare)..we see laser burn on the flex.

What is the acceptance criteria.  Looked in IPC-600 and 6013.  Does not address the laser cutting/burn situation.

OR if you have seen this and how was it handled.

Rashesh
Accurate Engg Inc.

______________________________________________________________________
This email has been scanned by the Symantec Email Security.cloud service.
For more information please contact helpdesk at x2960 or [log in to unmask] ______________________________________________________________________

______________________________________________________________________
This email has been scanned by the Symantec Email Security.cloud service.
For more information please contact helpdesk at x2960 or [log in to unmask] ______________________________________________________________________

______________________________________________________________________
This email has been scanned by the Symantec Email Security.cloud service.
For more information please contact helpdesk at x2960 or [log in to unmask] 
______________________________________________________________________

---------------------------------------------------------------------
This transmission (including any attachments) may contain confidential information, privileged material (including material protected by the solicitor-client or other applicable privileges), or constitute non-public information. Any use of this information by anyone other than the intended recipient is prohibited. If you have received this transmission in error, please immediately reply to the sender and delete this information from your system. Use, dissemination, distribution, or reproduction of this transmission by unintended recipients is not authorized and may be unlawful.

______________________________________________________________________
This email has been scanned by the Symantec Email Security.cloud service.
For more information please contact helpdesk at x2960 or [log in to unmask] 
______________________________________________________________________