... information to ensure that the finished board is to your requirements. - Always required even when a drill file is supplied, to enable inspection | MULTILAYER CIRCUIT BOARDS SHOP | of panels immediately after drilling and finished boards prior to despatching. Hole sizes must be clearly represented with distinct differences between each size. Tolerances are | MULTILAYER CIRCUIT BOARDS SHOP | not required unless different to our standard of +0.1 / -0.05 mm. - Preferred with overall mechanical dimensions including notches, cutouts and slots. Also preferred | MULTILAYER CIRCUIT BOARDS SHOP | is a positioning (datum) dimension (drilled hole is best). Tolerances are not required unless different to our standard of + / -0.25 mm. Other information | MULTILAYER CIRCUIT BOARDS SHOP | required for all boards includes: board thickness (standard = 1.6mm) base copper thickness (std = 18mm) solder mask colour (std = green) solder mask type | MULTILAYER CIRCUIT BOARDS SHOP | (std = liquid photoimageable) component legend colour (std = white) bare board testing requirement (std for multilayer and fine line production runs) Extra information required | MULTILAYER CIRCUIT BOARDS SHOP | for multilayers ...
[ Multilayer Circuit Boards Shop ]


... format for fabrication. It's widely used by many of the bare-board test-fixturing machines and is one of the only true ways to identify power- | MULTILAYER CIRCUIT BOARDS SHOP | to-ground shorts. With the information in this format coming directly from the engineering CAD system, there's no danger of the fabricator "reverse engineering" the netlist | MULTILAYER CIRCUIT BOARDS SHOP | from the Gerber files. Next up are the internal | PLANE LAYERS |. For some reason, CAD engineers like them to be "positive," but those | MULTILAYER CIRCUIT BOARDS SHOP | types of layers lead to huge file sizes. Negative plane layers are usually preferred by fabricators because they're easier to work with and have smaller | MULTILAYER CIRCUIT BOARDS SHOP | file sizes than positive layers. Remember, boards are manufactured en masse and must be stepped out into a panelized form. The result: Data sets with | MULTILAYER CIRCUIT BOARDS SHOP | lots of unnecessary positive planes swell exponentially, bog down CAM systems, and crash photoplotters. After the basic | PREP WORK | is completed, step into | MULTILAYER CIRCUIT BOARDS SHOP | the fabrication analysis arena, where the game is one of checks and balances. ...
[ Multilayer Circuit Boards Shop ]


... phase is approx. 0,25 mµ thick when delivered. During storage, the diffusion of copper in the tin surface continues, causing the thickness of the | MULTILAYER CIRCUIT BOARDS SHOP | pure copper or tin layers to decrease. If the blended metal reaches the surface it becomes coated with a non- removable oxide, making soldering impossible. | MULTILAYER CIRCUIT BOARDS SHOP | Storage possibilities of immersion tin PCBs are, for this reason, considerably limited compared with conventional SnPb techniques: stored PCBs should be used up within 3 | MULTILAYER CIRCUIT BOARDS SHOP | months and if time exceeds 6 months, heavy processing problems can occur. The price of immersion tin is between that of the classical SnPb and | MULTILAYER CIRCUIT BOARDS SHOP | the immersion nickel gold surfaces. However, thiourea, which is used in the production, does not conform with environmental or effluent requirements, therefore the future costs | MULTILAYER CIRCUIT BOARDS SHOP | for disposing of wastes are difficult to calculate, particularly in view of the upcoming, stricter environmental regulations. Conclusion Immersion tin can be seen as a | MULTILAYER CIRCUIT BOARDS SHOP | viable alternative, as the surface ...
[ Multilayer Circuit Boards Shop ]