Technical Library | 2015-06-30 22:02:41.0
This paper describes the losses from defects at the placement process in the SMT line. Two case studies of European and Taiwanese SMT manufacturers illustrate the actual losses from their defects. An evaluation method to select a pre-reflow AOI system maximizing the return on investment (ROI) is introduced. In the end, ROIs of three commercial pre-reflow AOI systems are compared to demonstrate the importance of selecting an appropriate AOI system. This paper will increase the probability that anyone installing an AOI system during the pre-reflow process will obtain a successful gain with short payback period.
Technical Library | 2021-04-15 14:49:27.0
In this study, a predefined template-based image processing system is proposed to automatically detect of PCB soldering defects that negatively affect circuit operation. The proposed system consists of a scaled inspection structure, a camera, an image processing algorithm merged with Fuzzy and template guided inspection process. The prototype is produced using a plastic material, depending on the focal length of the camera and the PCB size. Image processing step comprises two steps. Firstly, solder joints are determined and boxed using Fuzzy C-means clustering algorithm.
Technical Library | 2022-06-20 21:01:37.0
We've been doing a lot of print testing in our lab. In our first set of published results, "The Impact of Reduced Solder Alloy Powder Size on Solder Paste Print Performance1" from IPC/APEX 2016, we revealed a hierarchy of input variables to maximize solder paste transfer efficiency and minimize variation. In that study, we used a fully-optioned stencil as part of the equipment set. In order to tease out the data we were looking for, we could not lose critical information to the noise of stencil-induced variations.
Technical Library | 2023-05-22 16:42:56.0
Nano-coatings are applied to solder paste stencils with the intent of improving the solder paste printing process. Do they really make a noticeable improvement? The effect of Nano-coatings on solder paste print performance was investigated. Transfer efficiencies were studied across aperture sizes ranging from 0.30 to 0.80 area ratio. Also investigated were the effects of Nano-coatings on transfer efficiencies of tin-lead, lead-free, water soluble, no-clean, and type 3, 4, and 5 solder pastes. Solder paste print performance for each Nano-coating was summarized with respect to all of these variables.
Technical Library | 2023-10-19 22:03:14.0
Koh Young Technology, the industry leader in True 3D measurement-based inspection solutions, proudly releases another customer success story with Matric Group. This case study shows how Matric Group has leveraged their partnership with Koh Young to be one of the first in the industry to use pre-reflow AOI as a game-changer for line efficiency and improved yield. All while creating a central inspection war room to allow just one person to manage all inline inspection, increasing automation, and control and mitigating talent shortages.
Technical Library | 2009-05-07 23:23:00.0
Thermal fatigue has been one of the most serious problems for solder joint reliability. Thermo-mechanical fatigue failure is considered to be closely related to micro-structural coarsening (grain/phase growth). Factors that influence the phase growth are studied and measurement methods are discussed, including the preparation of the eutectic solder sample for phase size measurement. Three categories of models used to predict grain growth in polycrystalline materials are presented. Finally, phase growth in solder during high temperature aging and temperature cycling and its use as a damage correlation factor are discussed.
Technical Library | 2013-10-03 16:05:39.0
Printed Circuit Board (PCB) is an essential component of almost all electrical and electronic equipments. The rapid growth of the use of such equipments has contributed enormously to the generation of large quantity of waste PCBs. The WPCBs not only contain valuable metals but also a large variety of hazardous materials. Conventional treatments of such WPCBs have their own limitations. By pyrolysis of WPCBs, it is not only possible to obtain the organic part of it as a fuel or useful chemical but can make further processing to recover metals much easier and efficient. In the present work, a kinetic study on the low temperature pyrolysis of WPCBs using a thermogravimetric analyser has been attempted...
Technical Library | 2013-12-19 16:57:50.0
With the adoption of RoHS and implementation of Lead Free solders a major concern is how this will impact reliability. Both commercial and military hardware are impacted by this change even though military hardware is considered exempt from the requirements of RoHS. As the supply chain has moved to the new lead free alloys both markets are being forced to understand these impacts and form risk mitigation strategies to deal with the change. This paper documents the effect of mixing Leaded and Lead Free alloys on BGA devices and how this impacts reliability. Three of the most common pitch BGA packages are included in the study to determine if the risk is the same as pitches decrease
Technical Library | 2014-05-01 15:14:12.0
Bilayer graphene has been a subject of intense study in recent years. The interlayer registry between the layers can have dramatic effects on the electronic properties: for example, in the presence of a perpendicular electric field, a band gap appears in the electronic spectrum of so-called Bernal-stacked graphene. This band gap is intimately tied to a structural spontaneous symmetry breaking in bilayer graphene, where one of the graphene layers shifts by an atomic spacing with respect to the other. This shift can happen in multiple directions, resulting in multiple stacking domains with soliton-like structural boundaries between them
Technical Library | 2014-10-23 18:10:10.0
The functional reliability of electronic circuits determines the overall reliability of the product in which the final products are used. Market forces including more functionality in smaller components, no-clean lead-free solder technologies, competitive forces and automated assembly create process challenges. Cleanliness under the bottom terminations must be maintained in harsh environments. Residues under components can attract moisture and lead to leakage currents and the potential for electrochemical migration (...) The purpose of this research study is to evaluate innovative spray and soak methods for removing low residue flux residues and thoroughly rinsing under Bottom Termination and Leadless Components
