Technical Library | 2020-12-10 15:49:40.0
Electronic assemblies should have longer and longer service life. Today there are partially demanded 20 years of functional capability for electronics for automotive application. On the other hand, smaller components, such as resistors of size 0201, are able to endure an increasing number of thermal cycles until fail of solder joints, so these are tested sometimes up to 4000 cycles. But testing until the end of life is essential for the determination of failure rates and the prognosis of reliability. Such tests require a lot of time, but this is often not available in developing of new modules. A further acceleration by higher cycle temperatures is usually not possible, because the materials are already operated at the upper limit of the load. However, the duration can be shortened by the use of liquids for passive tests, which allow faster temperature changes and shorter dwell times because of better heat transfer compared to air. The question is whether such tests lead to comparable results and what failure mechanisms are becoming effective. The same goes for active temperature cycles, in which the components itself are heated from inside and the substrate remains comparatively cold. This paper describes the various accelerated temperature cycling tests, compares and evaluates the related degradation of solder joints.
Technical Library | 2021-05-13 16:03:25.0
Sn-based lead-free solders such as Sn-Ag-Cu, Sn-Cu, and Sn-Bi have been used extensively for a long time in the electronic packaging field. Recently, low-temperature Sn-Bi solder alloys attract much attention from industries for flexible printed circuit board (FPCB) applications. Low melting temperatures of Sn-Bi solders avoid warpage wherein printed circuit board and electronic parts deform or deviate from the initial state due to their thermal mismatch during soldering. However, the addition of alloying elements and nanoparticles Sn-Bi solders improves the melting temperature, wettability, microstructure, and mechanical properties. Improving the brittleness of the eutecticSn-58wt%Bi solder alloy by grain refinement of the Bi-phase becomes a hot topic. In this paper, literature studies about melting temperature, microstructure, inter-metallic thickness, and mechanical properties of Sn-Bi solder alloys upon alloying and nanoparticle addition are reviewed
Technical Library | 1999-05-06 10:46:06.0
Pentium-class portables present significant packaging problems. The heat generated inside a notebook not only reduces microprocessor reliability, but the reliability of peripheries such as hard drives and video chips. Although the processor is the primary heat-generating source, it isn’t always the component least tolerant of temperature...
Technical Library | 1999-05-06 11:52:21.0
The market's demand for increasingly powerful products, in smaller and smaller packaging, creates a cooling problem. Integrated circuit (IC) lifetime is dependent upon its operating temperature, creating a trade-off situation: either you enlarge the package to accept additional cooling, or you sacrifice IC lifetime.
Technical Library | 1999-07-20 09:28:38.0
With the increase in heat dissipation from microelectronic devices and the reduction in overall form factors, thermal management bmomes a more and more important element of electronic product design. Both the performance reliability and life expectancy of electronic equipment are inversely related to the component temperature of the equipment...
Technical Library | 1999-06-23 20:29:21.0
This paper outlines the harmful effects of out-of-control process parameters and describes methods of measuring and tracking them to keep them in control. It addresses all critical variables of wave soldering: flux deposition, preheat application, conveyor speed, solder temperature and solder contact time.
Technical Library | 2007-11-08 17:35:46.0
A continuous furnace is ideal for processes requiring high production volumes, process consistency, and precision control. This overview discusses some of the newer temperature and atmosphere capabilities of continuous furnaces and addresses the various components that make up a continuous furnace.
Technical Library | 2009-12-14 20:31:18.0
In this article, I will present a basic overview of soldering for those who are new to the world of soldering and for those who could use a refresher. I will discuss the definition of soldering, the basics of metallurgy, how to choose the proper alloy, the purpose of a flux, soldering temperatures, and typical heating sources for soldering operations.
Technical Library | 2011-06-09 13:29:17.0
Flatness measurement of electronic parts and assemblies, or PCB’s, has become increasingly critical as geometries become smaller: finer pitches, smaller solder ball volumes, thinner substrates, etc. Additionally, processing temperatures vary and can pla
Technical Library | 2011-08-25 17:47:23.0
While SnAgCu (SAC) alloys still dominate Pb-free selection in North America, especially Sn3.0Ag0.5Cu (SAC305), there are alternative material systems available. Any OEM that is concerned about the high reflow temperatures of SAC or relies on ODM, it is im
