Import Dfa Into Orcad Download And That

We provide the.dra,.psm, and.pad files for Allegro in the download and that should be sufficient to import it.

You can import a DXF file into it and get a footprint out of it.

The metal parts can still be in contact but not bound to one another.

Things have improved for the environment but Im not so sure I can say that about the workers.

Through-hole components were a breeze to install and rework if necessary.

Weve come a long way towards shrinking the products and that comes with the cost of shrinking the components.

Surface mount resistors and capacitors were just becoming a thing.

Up to that point, we measured the pin to pin pitch in fractions of an inch.

The leads were formed so that they could be inserted into holes that were a half of an inch apart.

They go all of the way around in a quad-flat-pack arrangement.

Those devices have evolved from 1.27 mm pitch down to 1 mm then 0.8 mm followed by 0.65, mm, 0.5 mm, 0.4 mm and now 0.35 mm and even 0.3 mm in some cases.

Electronic component assembly that had 0.1 to work with now got down to 0.016 or less.

Get ready to work with values up to 0.1F, 6.3vdc caps in 008004 (.25x.125mm) packages.

That is the magic formula of eutectic solder, 63 tin and 37 lead.

The beauty of eutectic solder is that it has a nice low melting point and that it solidifies over a very narrow temperature range.

Common lead-free solders have a higher melting point and are not so forgiving in the process window.

The PCB materials have to withstand searing heat that can cause all kinds of problems.

Any imbalance of copper in the boards construction will have a greater tendency to cause warpage and twist as the board comes out of the IR oven.

Imperfections in the finish coatings can result in blistering, measling, lifted pads, delamination or any number of solder defects.

In its pure form, tin has a nasty habit of spreading out and causing shorts.

Not only in the solder joints where tin whiskers are common but on the traces themselves.

Dendritic growth can form and cause shorts between adjacent traces.

This is where the dielectric materials break down and conductive salts can creep through the micro-cracks between the conductors.

Again, this is all related to the greener board materials we are compelled to use to save our planet from toxic pollution.

Meanwhile, the most important thing we can give to the Marketing team is a super-small PCB.

We designers have to walk a tightrope at the intersection of marketability, quality and reliability.

The result can actually crack a ceramic capacitor or pull the wire of an inductor or wire-wound resistor away from the terminal.