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Area in view is approx 5mm x 6 mm.. On this decoder design the square pads on the left and right hand side are for surface mount 0804 size resistors for easy hand assembly. My smaller decoder designs use 0402 resistors i.e. quarter the footprint by area. This is where micro robotic pick-and-place is needed... those little robots can do the job far better than my clumsy human digits.

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Discussion starter · #23 ·
Copper interconnect track widths are 0.15mm i.e. 150 microns.

I am 100% by the quality of the manufacture of these boards. Standard design practice avoids 90 degree corners for narrow tracks... using instead to 45 degree corners... lithography/etch can cause line thinning at 90 degree corners leading premature failures at minimum pitch. So to be avoided.

Also interesting to observe the three dimensional nature of the silk screen printed white labelling. Design rule checking prevents this printing from overlaying the windows in the solder mask.

Exposed copper areas are tinned with lead-free solder during the manufacturing process to reduce oxidation of the copper and to enhance solderability.

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Discussion starter · #25 ·
Hi Slotspeed - not sure I understand the question.

I would simply create them as a device and add to the library.

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Discussion starter · #26 ·
I mentioned a while back a plan to build a simple DIY robot pick-and-place system. The intention was to use two steps… solder paste dispense using a stepper motor driven paste syringe and then vacuum lift component pick-and-place.

My experience with the solder paste dispenser is that it functions nicely when used manually but sometimes the back-off/engage of the plunger misses a few pads. When doing things manually this is not a problem… the operator notices! but for a fully automated system it would be problematic.
Then… for the pick-and-place system… there are tried and tested designs in kit form for about 2500 euros. So that will make sense in due course.

For now I am busy prototyping designs including some with very small solder pads (e.g. WLCSP packages etc).

So my approach is…

1/ use the solder syringe for most component locations.

2/ use a stencil applied direct to the smallest parts (e.g. WLCSP parts and similar). So the solder is then placed directly onto the component. Then, position the component onto the board assisted by the placement robot.

Lets see if this works ;)

Meanwhile for QFN packages and above my current prototype assembly techniques using solder paste,tweezers, a fine tipped iron and hot air remain fine.

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