Hi Reuven - I think that is a possible idea, however, what void percentage do you suggest and what technical data/investigative studies do you have to support the recommended void percentage? One thing to consider is that if a workmanship topic is missing from the JSTD-001/IPC-610 documents, it doesn't mean that the topic hasn't been reviewed. The IPC committees work hard to only put workmanship criteria in the specifications that is necessary and is supported by data. An example - the IPC-7093 BTC committee completed extensive efforts looking at the voiding of QFN thermal pads and found no industry consensus on a void percentage requirement. The JSTD-001 committee therefore has not included a maximum void percentage requirement in the 001 specification and the IPC-610 specification shows no examples of voiding requirements of QFN thermal pads. The workmanship criteria show in the JSTD-001/IPC-610 specifications results in added costs to products and processes so the committees are very careful to not add requirements unless there is technical data/justification. I know a number of OEMs/CEMS who have a 50% maximum void requirement on the QFN thermal pad unless the component has specific thermal or electrical functional requirements. The IPC-7093 specification has some good information on the topic of BTC thermal pads and voids. The committees would welcome any investigative data on the topic too. Happy Holidays! Dave Hillman Rockwell Collins [log in to unmask] From: Reuven Rokah <[log in to unmask]> To: <[log in to unmask]> Date: 12/20/2013 12:48 AM Subject: [TN] IPC-A-610E, Voids in Thermal exposed pad of QFNs Sent by: TechNet <[log in to unmask]> Hi TechNets, I didn't see in the IPC-A-610E any acceptability reference in regards with the percentage of voids in solder joints of exposed thermal pads of QFNs or other components with exposed thermal pads. I recommend to add it in the next revision. -- Best Regards, *Reuven Rokah* Mobile: 972-52-6012018 Tel: 972-3-9360688 Fax: 076-5100674 <http://www.rokah-technologies.com/>[log in to unmask] [log in to unmask] www.rokah-technologies.com This e-mail message is intended for the recipient only and contains information which is CONFIDENTIAL and which may be proprietary of RokahTechnologies. If you have received this transmission in error, please inform me by e-mail, phone or fax, and then please delete all of the original files and all other copies exist. ______________________________________________________________________ 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] ______________________________________________________________________