Technical Library | 2009-07-01 09:24:25.0
During the last 5 years, the processes to remove flux residues especially for lead-free and challenging geometries have demonstrated new cleaning obstacles which have to be overcome.i A new methodology has been recently developed to further increase the propensity for successful cleaning.ii At the core of this method is the thermal identification of the residue matrix. Thermal energy changes the physical state, i.e. transitions between liquid, solid and gas phases. By taking advantage of such specific information during phase transitions, the cleaning process can be tailored to such settings, which in turn increases the cleaning success significantly.
Technical Library | 2009-09-18 14:42:37.0
In recent years, various studies have been issued on cleaning under low standoff components; most however, with incomplete information. It is essential to revisit and describe the latest challenges in the market, identifying obvious gaps in available information. Such information is crucial for potential and existing users to fully address the cleanliness levels under their respective components. With the emergence of lead-free soldering and even smaller components, new challenges have arisen including cleaning in gaps of less than 1-mil.
Technical Library | 2009-09-18 14:48:58.0
The stencil cleaner can be one of the most versatile tools on the manufacturing floor. It can be used to clean electronic modules in various stages of the manufacturing process. In fact, an automated stencil cleaner can clean just about anything you come up against in your PCB assembly process.
Technical Library | 2009-07-09 17:23:07.0
Sometimes you just cannot clean with water. Good examples of this are: circuits with batteries attached, cleaning prior to encapsulation, ionic cleanliness testing, and non-sealed or other water sensitive parts. High impedance or high voltage circuits need to be cleaned of flux residues and other soils to maximize performance and reliability and, in these types of circuits; water can be just as detrimental as fluxes. When solvent cleaning is called for, Hansen solubility parameters can help target the best solvent or solvent blend to remove the residue of interest, and prevent degradation of the assembly being manufactured. In short, using this approach can time, manufacturing cost and reduce product liability.
Technical Library | 2009-09-18 14:52:06.0
Electronic assembly cleaning processes are becoming increasingly more complex because of global environmental mandates and customer driven product performance requirements. Manufacturing strategies today require process equivalence. That is to say, if a product is made or modified in different locations or processes around the world, the result should be the same. If cleaning is a requirement, will existing electronic assembly cleaning processes meet the challenge? Innovative cleaning fluid and cleaning equipment designs provide improved functionality in both batch and continuous inline cleaning processes. The purpose of this designed experiment is to report optimized cleaning process parameters for removing lead-free flux residues on populated circuit assemblies using innovative cleaning fluid and batch cleaning equipment designs.
Technical Library | 2019-11-07 08:59:14.0
Inductors realized with high permeable MnZn ferrite require, unlike iron-powder cores with an inherent dis-tributed gap, a discrete air gap in the magnetic circuit to prevent saturation of the core material and/or tune the inductance value. This large discrete gap can be divided into several partial gaps in order to reduce the air gap stray field and consequently the proximity losses in the winding. The multi-gap core, realized by stacking several thin ferrite plates and inserting a non-magnetic spacer material between the plates, however, exhibits a substan-tial increase in core losses which cannot be explained from the intrinsic properties of the ferrite. In this paper, a comprehensive overview of the scientific literature regarding machining induced core losses in ferrite, dating back to the early 1970s, is provided which suggests that the observed excess core losses could be attributed to a deterioration of ferrite properties in the surface layer of the plates caused by mechanical stress exerted during machining.