Jason, if you help me, I will help you,
your question, yes there is a lot of job done, which follows:
1.Akay: A study of Life Prediction for PGAs
2.Akay: Experimental correlations of an energy-based fatigue life prediction for solder joints.
3.Akay: A Finite Element Study of Factors affecting Fatigure Life of Solder Joints.
4.Akay: Fatigue Prediction for Thermally loaded Solder Joints using a Volumetric Weibull averaging technique.
5.Akay: Experimental correlations of an energy based fatigue life prediction for solder joints.
6.Akay: FEM studies for PBGAs
I have been involved in intricate solder joint problems of the sort where FEM was used for simulating of solder geometries in NASTRAN. We have a whole team whose job is to predict the life for whole board and individual components. Not all is open information and modelling may not be available on the net for you. I will ask the guy what about it. G.G. if you read this, please, reply directly off-line to our friend.
During the time, mail to Hasan for copies of his famous reports above. He is professor on a Illinois Uni. E-mail: <[log in to unmask]> or <[log in to unmask]>
Now, you may help me, comrade,
have you done comparisons between 25um and 50um gold wire U/S bonding on gold thickfilm? Or have you some experienc from measuring/judging microhardness of the outmost surface of the thickfilm, on which you perform the bonding? Or do you have experience from upfloating glasses and oxides from the internal binders during firing at +850C? Or how to minimize scrren mesh imprints on the fired gold? Or what you like burnishing thickfilm gold?
You don't? Ah..I thought that was what all people talked about. Can there really be something more exciting? He-he.
See you later, alligator
Ingemar Hernefjord
Ericsson Microwave Systems
Delphi have responded already, but further replies are welcome.
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To: [log in to unmask]
Subject: Re: [TN] solder joint reliability prediction models
Is there anywhere I can obtain a model for predicting the life, strength, etc.
of a solder joint? I would like to be able to input data one of two ways to
determine what I can expect.
1. Can I input characteristics of the joint into some type of matrix i.e, hole
size, plating thk, hole fill, fillet concavity, and get a life prediction model?
2. From FEM, obtain predicted overall stress and strain for the joint then
extrapolate out into some life prediction model for reliability.
My primary concern are joints on the bottomside of a PCB either from wave solder
or the paste-in-hole process. I would appreciate direction or something
another.
Jason Smith
Process Materials Engineer
Lexmark Electronics
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