Issue link: https://iconnect007.uberflip.com/i/1499197
32 PCB007 MAGAZINE I MAY 2023 ASC has been using out- side sources for laser. But as we get into this, it's beneficial to have our own laser in-house, so we've recently put in a pur- chase order to get a brand-new laser drill. We have quite a bit of capital acquisition right now. We've refreshed our strip/etch/ strip line (SES), and our inner layer etch/strip line with vac- uum etching technology. Of all these changes, which ones are directly related to UHDI? An additive process is critical to get those sorts of dimensions in a laser drill. Which pieces are necessary to support getting to UHDI? In a sense, they all are necessary to getting there. We have been getting into other aspects where you have embedded capacitors and resistors. We've been working quite closely with the folks at Quantic in terms of the Ticer materials and the OhmegaPly® materials as well. It all must come together because ultra HDI needs many different aspects. e Averatek process that we're using as our vehicle to get to ultra-fine lines is the cornerstone. But you can't do fine lines without ultra-fine vias. We've added copper filling ability for our microvias and we've been upgrading our plating lines. We're moving to insoluble anode technology with special brighteners and levelers to control the plating distribution better from surface to the via; there are many pieces that make ultra HDI. You mentioned embedded components. Are you finding that sort of design decision going hand-in-hand with UHDI? at technology has been around for quite a while, probably since the 1980s. It's not neces- sarily part of ultra HDI as we describe it today, but back in those days, it was a very high-den- sity board. It has a function in the boards of the future as well. Are you seeing a higher percentage of that sort of implementation as embedded is specified more often? e boards are getting smaller and it's natural when they can take those components off the surface and put it inside. It's a key method for space savings there. Yes. ere's a lot of interest these days for pack- age substrates, which is nothing more than ultra-high density; we are looking toward that side of the business as well. We all know that UHDI has a lot of value in Mil-Aero, DoD, but your UHDI work is not necessarily in that space. What non-DoD sectors are you working in? All sectors, actually. We are working with DoD customers, but in some cases, they are working on new designs that are needed. Essentially, finer pitch components are really the push. If you look at a 0.5-millimeter BGA, we have customers that are struggling to get those routed. ey need to go to 2-mil lines and spaces or finer to route them. However, 0.5 millimeter won't be around long; we will get down to 0.35 mm and 0.3 mm. at will drive the industry crazy because you must have finer lines and spaces throughout. en you get to a point where you can only build these stacked microvias so high before reliability becomes a factor. When you look at these aspects, military will need UHDI; they cannot go offshore for this technology, so they're the greatest U.S. mar- ket we'll have. e same requirements are in the chip scale packaging substrate side of the business, but there are other applications that are all over— semiconductor testing, for example. John Johnson