The effect of thermal cycle profiles on solder joint damage

The relationship between the damage caused at different thermal cycles is very important. The whole of accelerated thermal cycle testing is based on the premise that damage at one cycle is representative of damage at a different cycle. In this paper, the relative damage caused by six thermal cycle profiles are predicted using Finite Element (FE) modelling and the results validated against experiments. Both creep strain and strain energy density were used as damage indicators and creep strain was found to correlate better with experiment. The validated FE model is then used to investigate the effect of altering each of the thermal profile parameters (ramp and swell times, hot and cold temperatures). The components used for testing are surface mount resistors - 1206, 0805 and 0603. The solders investigated are eutectic SnAgCu and eutectic SnAg.

Resulting trusts, joint borrowers and beneficial share

Reviews case law illustrating the courts' approach to beneficial ownership of property purchased in joint name by means of a joint mortgage but without any declaration of beneficial interest, the resulting trust and joint beneficial interest presumptions. Contrast the approach adopted in cases where one party made no contribution to the mortgage payments with those where both parties made a contribution. Highlights the courts' treatment of the right to buy discount afforded tenant purchasers and property purchased as a commercial venture rather than a home.

The role of joint training in practitioner development for learning disability services

The presentation explores and evaluates an innovation in education and training in which two different professional trainings (nursing and social work) are integrated to produce jointly qualified specialist practitioners.