Electronic – smd orientation for pick and place

eaglepcb-assemblysurface-mount

I am trying to confirm the right orientation for all the packages I am using in Eagle before sending for pick and place assembly. After reading a bit, I understand that there is no standard from one chip company to another.

My question is simple: can I know for sure the proper orientation based on the way the chip is positioned in the reel ?

SOT25 package I want to know rotation 0 orientation

Looking at the way leds are packaged, and knowing that rotation 0 for leds is cathode on the left and anode on the right, I would tend to think that I can get the rotation 0 orientation by looking at chip with the holes on the left: is that correct ?enter image description here

Best Answer

It's also worth considering the direction the board passes through the pick-and-place/wave solder line. In my experience, the pick-and-place programmers can handle the part rotation issue when they set up their programs.

However, ICs, especially those with fine pin-pitch, should generally be sent through the wave solder process with pins perpendicular to the wave. Otherwise, solder bridges between pins are much more likely to form, ruining your PCB assembly or setting you up for lots of rework.