Electronics Forum | Wed Mar 28 11:41:31 EST 2001 | jax
......So the more it weighs the better??? I'm not sure I follow. Did you mean to put "equal/less than" or were you answering a different question?
Electronics Forum | Thu Nov 01 17:42:45 EST 2001 | davef
Wolfgang is correct. Search the fine SMTnet Archives to find information on the component weight versus pad size during adhesiveless double sided reflow. Do not mess with different solder materials.
Electronics Forum | Mon Mar 09 11:43:59 EDT 2009 | pcbrown
Here is a formula that may help. C/P C= Component's weight in grams P= Total pad area in Sq. in. Must be less than or equal to 30 Parts larger than a 68 pin PLCC should use an adhesive. Hope this helps.
Electronics Forum | Mon Aug 19 20:45:31 EDT 2002 | davef
Bob Willis and Phil Zarrow have had a running commentary on the ability of reflowed solder to hold components on the bottom side during reflow. You can find references to their component weight to pad area rations in the fine SMTnet Archives. The
Electronics Forum | Thu Aug 25 20:00:31 EDT 2005 | Dave
Try Heller Industrie's website at http://www.hellerindustries.com They have a formula that they offer for free that calculates land pad geometry to component weight to prevent drop off of components during second reflow. If you can't find it, give t
Electronics Forum | Mon Jun 12 22:00:51 EDT 2000 | Dave F
Could be. What are your profiles? 2) Au finish fail => Could be, but that the connections can be made with hand soldering makes this a low probability cause, assuming the activity of the flux used in hand soldering is not significantly different fr
Electronics Forum | Tue Dec 04 09:48:43 EST 2001 | davef
Defining the thickness of solder between the lead and the pad, J-001 states "Properly wetted fillet shall be evident." J-001 is available from http://www.ipc.org. Factors that affect this are: * Amount and composition of solder * Amount and compo
Electronics Forum | Wed May 19 04:27:18 EDT 2004 | johnwnz
Also look at IPC 7095 which is all abotu BGA processes including rework. the profile will be 100% based on your board - how many layers, how many are ground & signal, how many of those are the BGA connected to directly or indirectly, the component we
Electronics Forum | Mon Jul 06 18:00:16 EDT 2015 | jwqc
Does any one know how to calculate BGA height change after reflow oven? I guess the calculation will be based on the component size, weight, ball diameter and ball count of the BGA, but how to get the actual height?
Electronics Forum | Fri Jul 24 02:32:35 EDT 1998 | Frank J. de Klein
| Hi, | We have encountered one serious problem that heavy packages falling down during second side reflow, especially for PLCC 84. I believe it caused by temperature profile setting. | Any good suggestion would be highly appreciated! | Stoney Tsai *
