Hi calexanian
i run myself a assembly house for 10 year
and personally 4% failure on 0805 / 0603 part board whit less that 100 part on each PCB was bit over expected rate
even if assemble "blind" 0805 / 0603 was a 20 year old assembly process so if parameter control was right you have no defect
and normally today shop have automated optical inspection system ,and operator manually inspect critical part
but many shop skip or do it fast for final inspection since it very labor intensive ,so cost money ..
Qoute"
bad plating , Via separation, Thermal shock that leads to latent failure, material incompatibility , Solder mask pealing or under oxidation, board washdown or defluxing issues"
all this was trouble that not normal and was clear sing that PCB fab not follow any of the IPC standard and quality control
as example final rinse water must have Resistivity over 1 to 5 M?·cm (cleaning solvent and flux was quite very conductive)
so easy to see if still have ionic contamination present on PCB whit a simple TDS meter reading of < 1PPM
Excavatoree
on video solder volume look good ,so it likely that it caused by ,wrong pressure on pick place head for push part on the past
and / or bad thermal profile of the reflow oven , for small batch it may bit harder to control the reflow ,put to many cold board on it may change to much it temperature ,so heat become non uniform and one side of the solder may melt before and surface tension twist part so one pad lift a bit and not solder (if part was push well on the part it stick a bit so it help)
that a huge issue on smaller part like 0402 that not have big mass so part flip (Tombstoning)
normally the guy at inspection find that part whit uneven pad or thermal mass and closely inspect it on every board
p.s. i not tell Dave PCB fail rate was really bad , ONLY a BIT over expected rate for that board ..
Best regard