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PPI Home > Applications > Via Drilling |
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PWB Via Drilling |
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Printed wiring boards require small via holes through the dielectric material that separates the copper layer. These holes are then plated in the PWB manufacturing process, making electrical connections between the layers for increased board functionality. The trend in the industry has been towards smaller holes, recently as small as 100mm to 150mm in diameter. Such holes are progressively more difficult to drill mechanically, and the PWB industry has turned to lasers to provide precise drilling of holes in both the dielectric (resin or resin/glass materials) and copper. Dielectric drilling is most effectively accomplished with a CO2 laser operating in the 9mm band. This has proven to be the laser wavelength of choice for high speed drilling of both the resin in RCC materials as well as resin/glass composites in FR4 materials. Copper drilling requires UV light from a high repetition rate diode-pumped solid state laser for good control and high speed.
Via Drilling in Ceramic Tape |
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| Similar to pressures in the rigid PWB industry to reduce via size, LTCC circuit manufacturers are looking what is beyond the limits of punch technology and seeing lasers. Green (unfired) ceramic tape is a very soft material that drills quite easily (including the mylar® backing sheet) and high drilling rates can be achieved with high repetition rate laser sources. The laser can create the signal vias, the thermal vias as well as the registration holes, ensuring very tight accuracy tolerances. | |||||||||||||||||||||||||||||||||||||||||
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