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


... pads are so tightly grouped that the dams between them are less than 0.003", it's better to construct a mask opening over the entire | MULTILAYER BOARDS FAB | group. That will make the fabricator's life much simpler. Bear in mind that a fabricator's spacing tolerances likely differ from yours. For example, take the | MULTILAYER BOARDS FAB | drill data. When laying out a board, you usually work with finished hole sizes. However, a fabricator must drill a hole larger than the finished | MULTILAYER BOARDS FAB | one, about 0.004" to 0.005" over, then plate down to the desired finished size. This can lead to problems in maintaining annular ring requirements and | MULTILAYER BOARDS FAB | copper spacing on internal layers. To meet manufacturing specs, the fabricator might have to modify the data, and that's the last thing you want. So | MULTILAYER BOARDS FAB | now we have an alternate reality: You've finished the PCB layout (check out those negative planes!). You output the 274X and IPC-D-356 netlist files. The | MULTILAYER BOARDS FAB | data are fed into a fab analysis tool and run through their paces. Clearances are good. No possible ...
[ Multilayer Boards Fab ]


... thus causing the thermal to be isolated from the rest of the ground plane. This may be the case with internal layer files, but | MULTILAYER BOARDS FAB | the external files can show the same data, such as the surface mount component's length and width. The operator must determine whether the aperture wheel | MULTILAYER BOARDS FAB | calls out X first and Y second or Y first and X second. The wrong choice may cause the surface mount land to short into | MULTILAYER BOARDS FAB | another feature or become oversized or undersized. A mistype of a circle instead of a square may deprive the SM component of a land that | MULTILAYER BOARDS FAB | is sufficient to ensure the component is level during wave soldering. When typed incorrectly, soldermask clearance sizes can result in mask on lands or enlarged | MULTILAYER BOARDS FAB | clearances that expose traces. Open Road: When asking a fabricator to manually manipulate the aperture wheel, the final part design is left to the front-end | MULTILAYER BOARDS FAB | operator. When a designer doesn't have the option to export files using 274X, it is always helpful to provide the plotted artwork to the ...
[ Multilayer Boards Fab ]