... more expensive; HAL only marginally so. Doubts - just a European attitude? So, what are the disadvantages ? European users, in particular, can list | CIRCUIT BOARDS | quite a few: the predominant one being, that for mixed components and other multi-thermic processes, the organic protection layer breaks off at temperatures above 150° | CIRCUIT BOARDS | C . All in all, the area of use for soldering at higher melting temperatures has not yet been reliably tested. In addition, OSP does | CIRCUIT BOARDS | not bond. The ability to bond with soldering paste – in particular with lead-free soldering paste – depends greatly on the soldering procedure, such as | CIRCUIT BOARDS | convection ovens with or without a nitrogen atmosphere, high cooker ovens, etc Tests so far show that bonding is not as good as with the | CIRCUIT BOARDS | other named surfaces. Therefore, the self-centralising effect is noticeably lower and requires greater precision of solder paste pressure. In addition, the test for soldering ability | CIRCUIT BOARDS | showed that emphasis should be placed on a suitable flux agent, as this, in ...
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... |Property of a material to reduce its viscosity under mechanical influence / shearing stress by means of pumping, stirring, squeegee pressure and to return | CIRCUIT BOARDS | to its original conditions after the stress has finished. Screen- printing inks, for instance, have a very high thixotropy. On account of the squeegee pressure | CIRCUIT BOARDS | and the movement the screen-printing ink becomes thinner and thus flows through the screen meshes onto the substrate to be coated. After lifting-off of the | CIRCUIT BOARDS | screen/stencil the ink must "stand"; it has to achieve its original condition rapidly and must not flow anymore, which ensures a good edge coverage. | | CIRCUIT BOARDS | TRACK / GAP: | Technical expression describing the minimum of conductor width (track or trace)  and the minimum Insulation width (gap) between two of them | CIRCUIT BOARDS | on a printed circuit board. Track/gap helps to define the degree of difficulty in the production of pcb`s. Track/gap is mostly measured in micron or | CIRCUIT BOARDS | in mil. | THROUGH CONNECTION | An electrical connection ...
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... | An additive process for obtaining conductive patterns which combines an electroless metal deposition on an unclad substrate with electroplating or with etching, or | CIRCUIT BOARDS | with both | SMOBC SOLDER MASK OVER BARE COPPER. | A method of fabricating a printed wiring board which results in the final metallization being | CIRCUIT BOARDS | copper with no other protective metal but the non soldered areas are coated by a solder resist, exposing only the component terminal areas. | SOLDER | CIRCUIT BOARDS | LEVELING |The process of dipping PCB's into hot liquids, or exposing them to liquid waves to achieve fusion. First, flux is applied to the board | CIRCUIT BOARDS | by dipping or brushing. Then the board is preheated in a liquid (maintained at 250 F). Next, the board is immersed in fusing liquid at | CIRCUIT BOARDS | 430 - 500 F. Finally, it is dipped in another 250 F liquid to cool it and reduce thermal shock. Thin fused coatings can be | CIRCUIT BOARDS | applied. | SOLDER RESISTS (SOLDERMASK) | Coatings which mask off and surface insulate those areas of a circuit where ...
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