Creep strain is probably the most important time-dependent damage accrual factor affecting solder joint reliability. Under typical multi-hour loading conditions, creep-induced strain is a complex time per cycle, the system. function of solder metallurgical structure, solder temperature, loading applied stress, and the spring constant of the combined part/lead/board The complex system level cree...

QFN packages have become mainstream designs for mobile applications. As more applications adopt the QFN style packages, I/O count requirements are increasing. The typical method for increasing pin count in a QFN package is to increase the body size to accommodate the additional lead fingers. This is undesirable though, as mobile device users are pushing for smaller package sizes. By using a dua...

The electromigration-induced failure in flip-chip eutectic SnPb solder joints with a 10m-thick Cu under-bump metallization (UBM) was studied without the effect of current crowding in the solder region. The current crowding occurred inside the UBM instead of in the solder joint at the current density of 3.0 × 10 A/cm because of the spreading of current in the very thick Cu UBM. In these joints, ...

The no-flow underfill has been invented and practiced in the industry for a few years. However, due to the interfering of silica fillers with solder joint formation, most no-flow underfills are not filled with silica fillers and hence have a high coefficient of thermal expansion (CTE), which is undesirable for high reliability. In a novel invention, a double-layer no-flow underfill is implement...

Title of Document: DETECTION OF INTERCONNECT FAILURE PRECURSORS USING RF IMPEDANCE ANALYSIS Daeil Kwon, Doctor of Philosophy (Ph.D.), 2010 Directed By: Chair Professor and Director, Michael Pecht, Department of Mechanical Engineering Many failures in electronics result from the loss of electrical continuity of common board-level interconnects such as solder joints. Measurement methods based on ...

Surface mount technology (SMT) is increasingly used in microelectronics to mount components by soldering onto the printed circuit board (PCB). The solder alloys are used as the electrical and mechanical connections between the component and the board. Fatigue failure of solder joints is recognized as a major cause of failure in electronic devices. An approach to this problem is to determine the...

Article history: Received 4 July 2009 Received in revised form 16 November 2009 Available online 29 January 2010 0026-2714/$ see front matter 2009 Elsevier Ltd. A doi:10.1016/j.microrel.2009.11.010 * Corresponding author. Address: Department of M University, P.O. Box 10028, Beaumont, TX 77710, USA +1 409 880 8121. E-mail address: [email protected] (X.J. Fan). In this paper, a variety of wafe...

Single solder interconnects were subjected to a series of combined tension–shear and compression–shear tests to determine their failure load. The failure envelope of these interconnects was obtained by plotting the normal component against the shear component of the failure load. The interconnect failure force map was found to be elliptical like the failure envelopes of many materials. The fail...

This study compared fabr/cation of silver solder joints by dental students using an orthodontic blowpipe .or a Hydroflame ® soldering unit. Fifty-eight students attended a lecture and observed demonstrations of silver solder/ng. Thirty students used a Hydroflame ® to prepare one practice solder joint and two technique solder joints. These students then prepared one practice solder joint and two...

Solder reflow connection of semiconductor devices to substrates has been shown to be a reliable, effective, and readily automated technique. Rigid copper spheres, which remain rigid during solder reflow, have been used successfully for some time as a major element of the contact joint. However, to expand the capability of such joints to larger devices such as multiple-transistor chips in hybrid...