... the mating surface. Two methods can be used. 1)nickel plating the entire contact, then gold plating the selected area, 2) nickel plating and then | MULTILAYER CIRCUITS PRODUCTION | gold flash over the entire contact, and finally a selective heavy gold plating in the desired contact area. | SEMI-ADDITIVE-PROCESS | An additive process for | MULTILAYER CIRCUITS PRODUCTION | obtaining conductive patterns which combines an electroless metal deposition on an unclad substrate with electroplating or with etching, or with both | SMOBC SOLDER MASK | MULTILAYER CIRCUITS PRODUCTION | OVER BARE COPPER. | A method of fabricating a printed wiring board which results in the final metallization being copper with no other protective metal | MULTILAYER CIRCUITS PRODUCTION | but the non soldered areas are coated by a solder resist, exposing only the component terminal areas. | SOLDER LEVELING |The process of dipping PCB's | MULTILAYER CIRCUITS PRODUCTION | into hot liquids, or exposing them to liquid waves to achieve fusion. First, flux is applied to the board by dipping or brushing. Then the | MULTILAYER CIRCUITS PRODUCTION | board is preheated in a liquid (maintained at 250 F). Next, the board is immersed ...
[ Multilayer Circuits Production ]


... of each chiefly depend upon the material being drilled and the optical properties of the laser. | PERFORMANCE IS EVERYTHING GENERALLY |, lasers remove | MULTILAYER CIRCUITS PRODUCTION | material by vaporizing it through one of two mechanisms that depend on the wavelength. CO2 lasers vaporize the material through photothermal ablation. UV lasers remove | MULTILAYER CIRCUITS PRODUCTION | material through a process called photochemical ablation, in which the higher-energy UV photons literally sever the chemical bonds of the absorbing material. Photochemical ablation forms | MULTILAYER CIRCUITS PRODUCTION | cleaner microvias, while photothermal ablation creates more debris in and around the microvia that must be removed. However, the debris is non-tenacious and is easily | MULTILAYER CIRCUITS PRODUCTION | removed by conventional cleaning techniques such as permangate desmear. Regardless of the ablation mechanism, high peak powers and short laser pulses give the best microvia | MULTILAYER CIRCUITS PRODUCTION | results. Each material has a unique ablation threshold, above which vaporization occurs for a given wavelength and laser fluence (energy/area). | ...
[ Multilayer Circuits Production ]


... and crash photoplotters. After the basic prep work is completed, step into the fabrication analysis arena, where the game is one of checks and | MULTILAYER CIRCUITS PRODUCTION | balances. You've got your design rules; fabricators have theirs. Checks and balances can resolve any conflicts between the two. Take soldermask layers, for instance. Often, | MULTILAYER CIRCUITS PRODUCTION | these layers are not "intelligent" layers within a CAD tool; that is, there is not much in the way of capability checking within the tool. | MULTILAYER CIRCUITS PRODUCTION | As a result, these are among the more troublesome layers for fabricators. The solution here is a fabrication analysis tool that can handle such issues | MULTILAYER CIRCUITS PRODUCTION | as clearances, coverage, webbing, and so forth. For instance, most fab shops want the largest possible clearances in a solder layer so that mask doesn't | MULTILAYER CIRCUITS PRODUCTION | end up on pads. On the flip side, copper is not supposed to be exposed. The two requirements - no mask on pads and unwanted | MULTILAYER CIRCUITS PRODUCTION | exposed copper - must be balanced. It is not easy to do. How can the designer help? Devise a standardized ...
[ Multilayer Circuits Production ]