... first generation of single-sided PCBs, and it has proved surprisingly adaptable as via sizes decrease, densities increase, and the complexity of multilayer boards (MLBs) | MULTILAYER BOARDS | escalates. Automated mechanical drilling systems equipped with multiple spindles, control-depth positioning, and high-velocity positioning tables can process several panels simultaneously to achieve higher throughput and | MULTILAYER BOARDS | lower processing costs. Mechanical drilling is an effective method for hole diameters larger than 0.010" (250 microns). Below 0.010", however, operational costs rise exponentially. For | MULTILAYER BOARDS | example, a manufacturer might get 5,000 hits per drill bit when forming 0.008" or 0.010" vias but only 1,000 hits per bit for 0.006" vias. | MULTILAYER BOARDS | However, recent advances in mechanical drilling technology such as high-speed spindles (Figure 4a and 4b) have increased drill bit life two to three times over | MULTILAYER BOARDS | previous generations of mechanical drills. And since the PCBs can be stacked, it is possible for mechanical drills to be ...
[ Multilayer Boards ]


... project an image of the mask onto the panel, whereas the conformal process incorporates the mask onto the panel itself. In either case, laser | MULTILAYER BOARDS | light passing through the holes in the mask forms the microvias by ablation. Optical or mechanical positioning can also be used to scan the beam | MULTILAYER BOARDS | across the mask. Nonetheless, the majority of laser-formed microvias are formed sequentially using the direct method rather than en masse using masks. CO2 lasers account | MULTILAYER BOARDS | for about 80 percent of the lasers used for blind via and microvia formation. CO2 lasers can emit up to 225 watts of average power | MULTILAYER BOARDS | at a wavelength of 9.4 microns, which is a good absorption wavelength for a large number of dielectric materials such as FR-4, RCF, polyimides, PTFE, | MULTILAYER BOARDS | and aramids. This technology, however, requires capacity in wet chemistry and thermal oxidation for copper preparation. | THE PERFORMANCE CHARACTERISTICS | of RF-excited CO2 lasers | MULTILAYER BOARDS | enable them to create microvias at high speed. In most dielectrics, for ...
[ Multilayer Boards ]


... important criteria is the presence of orientation marks within the boundary of board. These marks could be the board reference so long as it | MULTILAYER BOARDS | cannot be read from the other side. (This is for your protection to prevent the boards made inside out). Images should comply with design rules | MULTILAYER BOARDS | that will result in a board that will meet performance and cost requirements. - Scale must be given, tapes securely stuck to the backing sheet, | MULTILAYER BOARDS | track to pad & track to track joints complete and the backing sheet clean. - Scale must be given and be at least 2:1. Plots | MULTILAYER BOARDS | must also offer sharp edge definition and traces dense enough for blocking light when photographing. - Preferred on 7mil (178mm) thick base for stability. Films | MULTILAYER BOARDS | should be plotted on laser photoplotter or on vector photoplotter using a minimum resolution of ½mil (13mm). - Preferred in Gerber® format although accepted in | MULTILAYER BOARDS | other formats. (Refer to CID-014 for information on Documentation in Digital Form). - files are the only acceptable form ...
[ Multilayer Boards ]