A primer on the steps for building advanced PCBs.
To get more functionality out of boards but within the same or reduced board sizes or areas, OEMs are increasing the density of the product by means of high density interconnect (HDI) boards, which are PCBs with multiple layers vertically connected with blind or buried vias.
HDI PCBs use high-performance thin materials, and have fine copper lines and microvias. While various methods are available, some patented, some not, we use what’s known as Every Layer Interconnect (ELIC) technology, which produces very thin flexible PCBs with high functional density per unit area. Advanced HDI PCBs make use of multiple layers of copper-filled stacked in-pad microvias that enable interconnections with even greater complexity.
President Donald Trump issued an executive order in March that introduced an often-threatened but rarely used measure to the world economic picture: tariffs.
Trump’s edict, which as of this writing was due to go into effect on Mar. 23, places onerous taxes on imports of steel and aluminum – 25% and 10%, respectively. The moves, the president said, were to reset trade imbalances and protect domestic metal producers, which have been decimated over the past two decades.
Or have they? The adjusted domestic steel production year-to-date through Mar. 10 was 17.2 million net tons, at a capability utilization rate of 74%. That is down 0.2% from the 17,221,000 net tons during the same period last year, when the capability utilization rate was 74.6%.
By comparison, total and finished steel imports over the same period were a combined 7.6 million NT net tons. The estimated finished steel import market share is 25% year-to-date.
One approach: Aperture designs that reduce paste volume from the inside wall.
While the primary theme of this column over the past few years has been miniaturization’s impact on stencil printing, standard SMT process challenges are alive and well. In many applications, where average device dimensions are large compared to the latest package footprints, reducing traditional defects is still a battle. One such frustration: mid-chip solder balls. To understand how to correct this well-known defect, one must appreciate the origin.
Mid-chip solder balls are most often observed with passive devices, specifically, resistors and capacitors. Since these chips have terminations on each end, solder paste material is deposited on two corresponding pads on the board; an open space of solder mask-defined PCB lies between them.
Is the bigger issue a lack of trust of those who don’t “look” like us?
A month ago I had a conversation with a guy who worked for me in my corporate days. We were discussing the #MeToo movement, and he said, “I’m no longer sure where the line is drawn.” This surprised me because over the two decades I’ve known my friend he has never been anything but great to work with. When someone like him is concerned about crossing an invisible line, it scares me. To me, the #MeToo movement has started a conversation that could end up improving opportunities and working conditions for women, or hardening the glass ceiling.
Before the “you don’t know what women have gone through” mail starts, let me say I deeply understand the pain and anger that drives #MeToo. I’ve been inappropriately propositioned in a board room and at industry events more times than I can count. But what was much harder to deal with as I moved up in my career was getting a boss who really didn’t think women should run sales organizations and dealt with that by doing everything possible to destroy my credibility with his boss and my team. I won’t go into details, but I left for a job that paid twice as much and the best boss I’ve ever had.
Explaining solder joint defects, one interruption at a time.
“Thank you all for promptly joining this morning’s webmail conference call. Today we are going to review the x-ray images our outside lab FTP’d us yesterday. Please set your phones on mute by pressing *6 if you are not speaking, and set your computers to the link provided by the meeting invite. You can unmute your phones in the same way, by pressing *6, if you wish to contribute to the conversation. You may listen via phone link, or by plugging earbuds into your laptops and activating sound. If you feel compelled to speak, unmute your phone and speak one at a time. We’d like to give equal time to as many members of our several participating engineering groups as possible. We have a big agenda, and many participants, so let’s get started.”
Here we go. Amateur hour.