Powder abrasion is an effective means for removing UV-curable materials.

Should finer solder particle sizes result in better process results? Our work suggests no.

In December we discussed a solder paste material evaluation for printing metric 0201 assembly. In summary, three solder pastes – two type 5 materials and one type 6 material – were analyzed by stencil printing them onto a PCB with an array of different patterns and two different pad designs of 100µm x 115µm and 125µm x 115µm, respectively, with three different component pitches of 100µm, 75µm and 50µm. In the end, the supplier A type 5 (T5) solder paste had the least variability, even with the 50µm interspace. The supplier B type 6 (T6) paste deposits appeared almost over-printed, with large deposit volumes and some wet bridging.

For component placement and reflow analysis, which were carried out on a Siplace TX placement machine and a Rehm nitrogen-capable reflow oven, the best-performing T5 paste from supplier A and the supplier B T6 paste were used. In addition to the original PCB design (PCB 1) containing discrete pad designs without traces, a second test PCB (PCB 2) integrated the same pad dimensions but with the addition of a conjoined trace between pads. Our observations were as follows:

Is automotive, not military or space, the impetus behind today’s electronics innovation?

Never say never. Every time I even think of saying “I will never,” something happens that makes me regret it. And yet here I am, once again, admitting to another of those instances of “I will never.”

This time, I allowed my experiences and background to cloud the reality on the ground. I started my career in the shadows of NASA. That great American technological juggernaut began when Kennedy challenged us to land a man on the moon and return him safely to earth. Conceptually, it all seemed so simple. For generations the US government, originally through the military and later with NASA’s help, drove dramatic technological advances by investing in new technology and the materials and processes necessary to achieve them, so that besides filling their immediate needs, those technologies would eventually become commercial standards integrated into consumer products.

As the seasons changed, so did the economic winds.

Housing price increases had outpaced the demand curve, as unit sales slowed and new starts cooled. Automotive sales dived for the longest stretch in years. The stock market tanked. Interest rates ticked up. The bond yield curve inverted, suggesting investors had turned pessimistic about short-term prospects for the economy. Foreign investment stalled. The government, having primed the consumer economic pump through huge capital inflows to the domestic economy, struggled over hard choices of whether to borrow even more in the hopes of stemming a potential recession.

Faced with all of the above, coupled with rising labor costs, a cascade of confusing new government rules, and an increasingly treacherous trade environment, manufacturers started looking for friendlier climes.