Components stand After reflow.Luo What you describe is called Tombstoning and is caused by different cooling rates between the two ends of the component. i.e. 8mil track on one side and solid plane on the other side.
The plane acts as a heatsink and pulls the component vertical before the other side can cool. to remedy match track thickness on both sides. Ian Capps ----- Original Message ----- From: Luo ; Yu-Ming (ù�ɯ� IAC-N) To: Protel EDA Forum Sent: Monday, March 03, 2003 12:35 PM Subject: [PEDA] Components stand After reflow. Dear All, I always set the polygon connect to pads directly, and it always work fine. But now, we found there are components stand after reflow, some contain pads connect to polygon, some not. I wonder if this is caused by the polygon connet style or any other reason. So my question is: 1, what are the key points to cause components stand after reflow? 2, When will components-stand always occur during reflow process? Preheat or cool. 3, How to slove this problem? I am looking forward to your constructive suggestions, any input would be great appreciated! Best Regards, Luo. * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * To post a message: mailto:[EMAIL PROTECTED] * * To leave this list visit: * http://www.techservinc.com/protelusers/leave.html * * Contact the list manager: * mailto:[EMAIL PROTECTED] * * Forum Guidelines Rules: * http://www.techservinc.com/protelusers/forumrules.html * * Browse or Search previous postings: * http://www.mail-archive.com/[EMAIL PROTECTED] * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
