Issue link: https://iconnect007.uberflip.com/i/1484263
28 PCB007 MAGAZINE I NOVEMBER 2022 vive because there are not too many of them, and you will not see the whole industry turn into this overnight. ere will always be enough orders for those who invest today. It's almost independent of the recession that we might see in the rest of the electronics industry. Matties: Looking at equipment, the two big pieces a fabricator really needs to invest in are imaging and AOI? Pedersen: Imaging, AOI, and copper plating is needed. You must have a plating system that is able to do this resolution. Matties: Is that the equipment, or is that chem- ical? Pedersen: Both. Vertical plating is needed, when they go to mSAP. Andy Shaughnessy: Some fabricators tell us that the main hurdle to starting UHDI was getting an LDI machine, which can run $800,000 or $900,000. Pedersen: You're absolutely right. It's LDI and AOI. You need a better AOI. But it depends on what level you are starting from. If you are an HDI factory where you have vertical plating and up-to-date etching lines, you will be able to cope with using that and adding LDI and AOI. You need both. When you have an LDI that is bringing you down to 20-micron track and gap and your AOI stops at 35, what do you do now? Shaughnessy: One thing we've heard is that North America has no real clue about how big a problem cleanliness is at that level. Little par- ticulates that are not a problem at 5-mil lines and spaces can kill a board at 15 microns, right? Pedersen: Yes, now you're talking about the facilities. You have equipment that you need for the processing, but the facilities around almost need a cleanroom area, at least where you are doing imaging and solder mask. If you are producing an HDI board today, you will need this certain cleanness level, but you need to extend that further when going into UHDI. Johnson: I'll give an example. Back when IC was doing manufacturing in these sorts of dimensions, 15 microns and so forth, the clean- room would have a restriction on employ- ees. ey couldn't be smokers, for example, because if they percolated even one nicotine molecule out of the pores of their skin and it landed on an IC, it could short it out. Now we're starting to deal with these sorts of dimensions in a printed circuit board. Clean- liness is important. We're now talking about molecular shorts. Pedersen: Yes, these things are important, and they are basic when you come down to these levels. You need to take care. We have been moving from a 100-micron track and gap on the standard PCB, going into HDI where you suddenly have a cleanroom for the solder mask, and all the things you need to just go to the next level when you are going down this ladder. is will bring us to another level, down to 20-micron track and gap, and further down to 15. I have customers asking for 17-micron track and gap now, and I can't deliver to them. ere are factories that can do it, but I don't have access to them. It's similar to when I was in Taiwan 20 years ago going into the factory, you were asked to wear protective clothes to enter the facility. There will always be enough orders for those who invest today.