I apologize for being wordy but the fact is that the correct application of thieving is critical to successful fabrication on the PCB - certainly as technologies continue to improve and a rounded understanding of its uses may allow for designers to grant the OK more often for in-board thief. Jeffrey Bush Director, Quality Assurance and Technical Support VERMONT CIRCUITS INCORPORATED 76 Technology Drive - POB 1890 Brattleboro, Vermont 05302 Voice: 802.257.4571.21 Fax: 802.257.0011 http://www.vtcircuits.com -----Original Message----- From: Franklin Asbell [mailto:[log in to unmask]] Sent: Friday, July 22, 2005 4:33 PM To: [log in to unmask] Subject: Re: [TN] layman's definition of theiving I'm guessing "laymen" speak different in the Great Northeast than in the rest of the country...hmmmm (grin) Franklin ----- Original Message ----- From: "Jeffrey Bush" <[log in to unmask]> To: <[log in to unmask]> Sent: Friday, July 22, 2005 3:00 PM Subject: Re: [TN] layman's definition of theiving Internal thieving is an important factor the PCB panel design. This serves to provide a uniform flow restriction to the bonding materials as it is processed in the lamination cycle under heat and pressure. The base materials are inherently instable and will be influenced in movement during lamination in relation to the resin flow conditions. This reduces positional differences that result from core to core and panel to panel. The placement of thief also provides a uniform pressure throughout the stack of panels in the lamination book being processed, which also has affects related to stability and bonding conditions of materials in the package. External thief, thus it name, is to normalize the current densities across the panel being plated. Constant ASF produces high and low current densities which cause gradients in plating thickness and also deposit characteristics due to brightener variations at the plating site. The PCB house is at liberty to add out-board thief were needed to balance the process conditions for a given design. The designers should also develop a criteria to grant the variation to the PCB house to add in-board thief where needed to further optimize the process. Many designers direct the minimum spacing required for the addition and many times "keep out areas" that are sensitive to additional basis metal. This provides needed latitude in many cases to improve the fabrication conditions of a design. Jeffrey Bush Director, Quality Assurance and Technical Support VERMONT CIRCUITS INCORPORATED 76 Technology Drive - POB 1890 Brattleboro, Vermont 05302 Voice: 802.257.4571.21 Fax: 802.257.0011 http://www.vtcircuits.com -----Original Message----- From: Phil Nutting [mailto:[log in to unmask]] Sent: Friday, July 22, 2005 2:35 PM To: [log in to unmask] Subject: [TN] layman's definition of theiving Ok, I have to admit my lack of knowledge. Can someone point me to a the Cliff's Notes version of Theiving on PC boards? Thanks in advance. Phil --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 1.8e To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 ----------------------------------------------------- --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 1.8e To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 ----------------------------------------------------- --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 1.8e To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 ----------------------------------------------------- --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 1.8e To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 -----------------------------------------------------