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We asked for you to send in your questions for Happy Holden, and you took us up on it! The questions you've posed run the gamut, covering technology, the worldwide fab market, and everything in between.
Quite a few of you asked about issues related to vias. Here's an example:
Q: If I use a 0.1-mm via-in-pad (non-stacked vias), is it okay to leave the via unplugged on the basis that the via is blind and very short (no significant solder wicking)?
A: Under most situations, as long as the device connection (the ball on the BGA) does not "plug" the via, it will reflow smoothly. But check with the assembler, as their process may not work well with unplugged blind vias-in-pads.
To pose your question for Happy Holden, take the survey by clicking here.
I-Connect007 Editorial Team
Any discussion about high-speed PCB design techniques would be incomplete without considering the properties and requirements of the materials. Your material selection drives much of your design strategy when you’re operating at 28 gigabits per second or faster.
We recently spoke with high-speed design expert Lee Ritchey of Speeding Edge, and electronic materials veteran Tarun Amla of Avishtech and Thintronics, about the relationship between advanced PCB materials and high-speed design techniques. They discuss the challenges facing designers and engineers working with materials at speeds that were considered unreachable not long ago, and what designers need to know about material selection as board speeds continue rising toward the stratosphere.
Anaya Vardya, American Standard Circuits
Heat cannot be efficiently exchanged with stagnant air surrounding a hot device; however, it can be transferred away from the electronic component to the PCB using thermal vias. A thermal via is a good conductor of heat that runs between the top layer and bottom layer of the PCB, dissipating heat through simple conduction. In simple terms, thermal vias are plated holes located under, or electrically connected to, a surface-mounted heat source on a PCB that allows heat transfer through the hole.
Weifeng Liu, PhD, Flex
This article will present a hybrid manufacturing process to manufacture FHE systems with a two-layer interconnect structure utilizing screen printing of silver conductive ink, filled microvias to connect ink traces at the different layers, and use of the traditional reflow process to attach the semiconductor chips to the printed substrates.