Technical Library | 2023-01-17 17:19:44.0
A test program was developed to evaluate the effectiveness of vacuum reflow processing on solder joint voiding and subsequent thermal cycling performance. Area array package test vehicles were assembled using conventional reflow processing and a solder paste that generated substantial void content in the solder joints. Half of the population of test vehicles then were re-processed (reflowed) using vacuum reflow. Transmission x-ray inspection showed a significant reduction in solder voiding after vacuum processing. The solder attachment reliability of the conventional and vacuum reflowed test vehicles was characterized and compared using two different accelerated thermal cycling profiles. The thermal cycling results are discussed in terms of the general impact of voiding on solder thermal fatigue reliability, results from the open literature, and the evolving industry standards for solder voiding. Recommendations are made for further work based on other void reduction methods and additional reliability studies.
Technical Library | 2023-01-17 17:12:33.0
Reflowed indium metal has for decades been the standard for solder thermal interface materials (solder TIMs or sTIMs) in most high-performance computing (HPC) TIM1 applications. The IEEE Heterogeneous Integration Thermal roadmap states that new thermal interface materials solutions must provide a path to the successful application of increased total-package die areas up to 100cm2. While GPU architectures are relatively isothermal during usage, CPU hotspots in complex heterogeneously-integrated modules will need to be able to handle heat flux hotspots up to 1000W/cm2 within the next two years. Indium and its alloys are used as reflowed solder thermal interface materials in both CPU and GPU "die to lid/heat spreader" (TIM1) applications. Their high bulk thermal conductivity and proven long-term reliability suit them well for extreme thermomechanical stresses. Voiding is the most important failure mode and has been studied by x-ray. The effects of surface pretreatment, pressure during reflow, solder flux type/fluxless processing, and preform design parameters, such as alloy type, are also examined. The paper includes data on both vacuum and pressure (autoclave) reflow of sTIMs, which is becoming necessary to meet upcoming requirements for ultralow voiding in some instances.
Technical Library | 2013-01-24 20:15:46.0
Being found in the search engines for a wide variety of terms directly related to my business would be my 1st priority...
Technical Library | 2021-06-02 19:43:00.0
A glossary of Industry 4.0 Terms to Know
Technical Library | 1999-05-07 09:58:23.0
From the point of view of an operating system, a computer is managed and optimized in terms of the application programming model and the management of system resources. For the TFLOPS system, the problem is to manage and optimize large scale parallelism. This paper looks at the management in terms of three key topics: memory management, communication, and input/output.
Technical Library | 2024-06-19 14:23:36.0
These guidelines on long-term storage are intended to help develop a supply strategy for components which need to be warehoused, processed and used beyond ...
Technical Library | 2011-02-24 19:20:14.0
In the selective soldering process, dross can be detrimental. Dross (and I use this term to encompass all surface contamination) is created in conjunction with the presence of Oxygen in two different areas of the process, and by separate means. Each must
Technical Library | 2011-11-16 22:11:58.0
Flexible Circuits are proven, reliable interconnect solutions for many of today's electronic packages. This article gives some general guidelines in terms of "dos" and "don'ts" that will help the engineer or designer make better decisions when using flex
Technical Library | 2011-12-15 17:21:42.0
manganese dioxide or conductive polymer cathode. Higher stability is achieved by placement of the capacitor into an SMD case filled by an inert atmosphere and hermetically sealed. The long term stability testing performed on such hermetically sealed capac
Technical Library | 2014-10-16 16:39:12.0
Key points are: *Long-term storage of BGA & QFP products may be required due to: Fab and assembly factory transfers Product obsolescence requiring customers make lifetime/EOL purchases Providing extended service (10+ years) on vehicles Other program needs * Integrity of EOL products in terms of solderability needs to be verified.
