Technical Library | 2018-09-21 10:12:53.0
Moisture accumulates during storage and industry practice recommends specific levels of baking to avoid delamination. This paper will discuss the use of capacitance measurements to follow the absorption and desorption behaviour of moisture. The PCB design used in this work, focused on the issue of baking out moisture trapped between copper planes. The PCB was designed with different densities of plated through holes and drilled holes in external copper planes, with capacitance sensors located on the inner layers. For trapped volumes between copper planes, the distance between holes proved to be critical in affecting the desorption rate. For fully saturated PCBs, the desorption time at elevated temperatures was observed to be in the order of hundreds of hours. Finite difference diffusion modelling was carried out for moisture desorption behaviour for plated through holes and drilled holes in copper planes. A meshed copper plane was also modelled evaluating its effectiveness for assisting moisture removal and decreasing bake times. Results also showed, that in certain circumstances, regions of the PCB under copper planes initially increase in moisture during baking.
Technical Library | 2019-08-14 22:20:55.0
Cleanliness is a product of design, including component density, standoff height and the cleaning equipment’s ability to deliver the cleaning agent to the source of residue. The presence of manufacturing process soil, such as flux residue, incompletely activated flux, incompletely cured solder masks, debris from handling and processing fixtures, and incomplete removal of cleaning fluids can hinder the functional lifetime of the product. Contaminates trapped under a component are more problematic to failure. Advanced test methods are needed to obtain "objective evidence" for removing flux residues under leadless components.Cleaning process performance is a function of cleaning capacity and defined cleanliness. Cleaning performance can be influenced by the PCB design, cleaning material, cleaning machine, reflow conditions and a wide range of process parameters.This research project is designed to study visual flux residues trapped under the bottom termination of leadless components. This paper will research a non-destructive visual method that can be used to study the cleanability of solder pastes, cleaning material effectiveness for the soil, cleaning machine effectiveness and process parameters needed to render a clean part.
Industry News | 2017-03-10 16:38:39.0
On Wednesday, March 29 Kester’s Bruno Tolla and Kyzen’s Mike Bixenman will present “Development of a Risk Profile from Flux Residues Trapped under Leadless Components” at the SMTA South East Asia Technical Conference on Electronics Assembly.
Swiftmode's Hyperclean Under Stencil SMT Wiper Rolls are the only product in the market that has beed developed specifically for the application. Best vacuum performance, less IPA usage and No loose fibres making the solder paste printing process mor
BTU’s Pyramax™ family of high-throughput thermal processing systems is widely recognized as the global standard of excellence for both printed circuit board solder reflow and for semiconductor packaging. Pyramax™ systems provi
Used SMT Equipment | Soldering - Reflow
The SMRO-4000 Scirocco Reflow oven has been developed for reflow soldering of Hybrid boards, SMT boards and Curing Glue or thin film pastes. The machine is developed for medium to large series of assembly. The Scirocco is based on hot air convection.
Used SMT Equipment | Soldering - Reflow
The SMRO-4000 Scirocco Reflow oven has been developed for reflow soldering of Hybrid boards, SMT boards and Curing Glue or thin film pastes. The machine is developed for medium to large series of assembly. The Scirocco is based on hot air convection.
Used SMT Equipment | Soldering - Reflow
The SMRO-4000 Scirocco Reflow oven has been developed for reflow soldering of Hybrid boards, SMT boards and Curing Glue or thin film pastes. The machine is developed for medium to large series of assembly. The Scirocco is based on hot air convection.
Industry News | 2002-05-13 08:43:26.0
Microscopic Cage that Traps Heat and Light that Would Normally Escape from a System and Transforms It into Usable Energy
In many cases the casting process is carried out under a vacuum to prevent air pockets. Trapped air bubbles reduce heat dissipation, since air is a good heat insulator, or they give rise to disruptive electrical charges in high-voltage applications,
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