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 17:22:28.0
The impact of voiding on the solder joint integrity of ball grid arrays (BGAs)/chip scale packages (CSPs) can be a topic of lengthy and energetic discussion. Detailed industry investigations have shown that voids have little effect on solder joint integrity unless they fall into specific location/geometry configurations. These investigations have focused on thermal cycle testing at 0°C-100°C, which is typically used to evaluate commercial electronic products. This paper documents an investigation to determine the impact of voids in BGA and CSP components using thermal cycle testing (-55°C to +125°C) in accordance with the IPC- 9701 specification for tin/lead solder alloys. This temperature range is more typical of military and other high performance product use environments. A proposed BGA void requirement revision for the IPC-JSTD-001 specification will be extracted from the results analysis.
Industry Directory | Manufacturer
Reflow ovens for automated SMT PCB assembly, specializing in lead free processing and nitrogen reflow. The best convection reflow ovens on the market.
This elevator format oven utilizes vertical space to accomodate curing applications of up to 4 hours while only occupying 96" (2.5m) of floorspace. Perfect for underfill and encapsulant.
Industry News | 2003-06-23 08:49:39.0
Three Organizations from the US, Europe and Japan to
ACI Technologies Inc. (ACI) is a scientific research corporation dedicated to the advancement of electronics manufacturing processes and materials for The Department of Defense and industry. This video provides an overview of our commercial service
Industry News | 2003-05-06 08:21:44.0
Will address key issues in the
Industry News | 2010-12-17 21:02:56.0
The SMTA is pleased to announce the Best Papers from SMTA International 2010. As speakers at SMTA International, individuals make contributions to the industry by sharing their research and findings. To reward exceptional achievement, $1,000 awards and plaques are given for the Best of Conference Presentation, Best of Proceedings Paper, and the Best International Paper.
ACI Technologies Inc. (ACI) is a scientific research corporation dedicated to the advancement of electronics manufacturing processes and materials for The Department of Defense and industry. This video provides an overview of our commercial service
Technical Library | 2012-12-17 22:05:22.0
Package on Package (PoP) has become a relatively common component being used in mobile electronics as it allows for saving space in the board layout due to the 3D package layout. To insure device reliability through drop tests and thermal cycling as well as for protecting proprietary programming of the device either one or both interconnect layers are typically underfilled. When underfill is applied to a PoP, or any component for that matter, there is a requirement that the board layout is such that there is room for an underfill reservoir so that the underfill material does not come in contact with surrounding components. The preferred method to dispensing the underfill material is through a jetting process that minimizes the wet out area of the fluid reservoir compared to traditional needle dispensing. To further minimize the wet out area multiple passes are used so that the material required to underfill the component is not dispensed at once requiring a greater wet out area. Dispensing the underfill material in multiple passes is an effective way to reduce the wet out area and decrease the distance that surrounding components can be placed, however, this comes with a process compromise of additional processing time in the underfill dispenser. The purpose of this paper is to provide insight to the inverse relationship that exists between the wet out area of the underfill reservoir and the production time for the underfill process.
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