HDI PCB

There is no denying that high-density interconnect (HDI) has been around a long time—over 25 years, believe it or not. we learned that while half of the respondents have less than 25% of their production in HDI boards, for some 28% it accounts for more than half their business, and a for a third of those, HDI is their main technology. In addition, 30% of all respondents expected their percentage of HDI work to grow to at least 25% and 45% expected it to represent more than half their business.

According to our respondents, the three main industry segments using HDI were telecommunications, automotive and consumer electronics. We then asked about market trends: What market trends are driving your HDI work? Obviously, a multi-answer question, but note that many of the answers have to do with density on the board.

Now, think back 25 years and you realize that fine features on a PCB were certainly not the same as they are now, and neither were the chip packages being used. Drilling, imaging and other PCB processes have made significant advances as you can imagine. And today’s densely-packed semiconductor packages are making HDI a necessity for many types of boards for many more applications—think electronics in cars, medical electronics and your incredible smartphone—all making use of components with many, many more I/Os and finer pitches (imagine what Moore’s Law has done in 25 years!). How to fit all those connections into a finite area on a PCB? So, it’s with all this in mind that we delve into this month’s issue on HDI, which is not for the faint of heart or the light reader!

Of course, we can’t talk about HDI without first hearing from the acknowledged “Father of HDI,” Happy Holden. And Happy has put together our intro article on the subject. He provides the proverbial wakeup we need to move all the faster into it. He points out concerns and obstacles and what needs to be done to overcome them.