Laser Drilled Blind and Buried Vias
Common Issues / Saturn Solutions
Saturn is one of the 50 largest PCB fabricators in North America, and is regularly studying new materials and methods to help save costs. Over the past year, we have taken delivery on 4 Mania Micronics drilling machines that utilize the latest in PCB Via Formation technology including linear X, Y, and Z drives, contact drilling sensing systems, and latest PLC instrumentation. These advancements combine to allow for only a 0.5 mil z-axis tolerance, which enables us to use mechanical drilling for vias down to 4 mils in diameter and 4 mils deep (1:1 aspect ratio) without the use of more expensive, and rare, laser drilling systems. Should you have blind via designs that are more aggressive than can be drilled on these latest technology mechanical drilling systems, we also have an in-house CO2 / YAG laser drilling system.
Voids—Desmear / DeAsh
To insure that blind vias are properly desmeared and deashed (if laser drilled), we utilize a two-step desmear process. This process first requires that the panels be submitted to a plasma conditioning process in our March Plasma System. We then process through a chemical desmear that has been optimized for micro- and blind vias. This line has been outfitted with long-stroke agitation and flight bar vibration to enhance fluid movement and prevent air bubble entrapment.
We have installed a Hollmuller Shadow hole preparation line that has been outfitted with advanced spray technologies. These spray technologies allow us to use this high-reliability hole preparation process for blind vias.
Further, our copper plating lines have been outfitted with long-stroke agitation and flight bar vibration to enhance fluid movement and prevent air bubble entrapment. By 2010, we expect to have installed Reverse Pulse Plating in our facility to plate even the most aggressive designs, and also to copper fill these so that your blind vias can also be used as via-in-pad technology.