I. The SMT pick and place machine cycle
The mounting period is the most basic parameter of the marking mounting speed. It refers to the time taken from picking up the components, after testing, pasting them on PCB and returning to the location of the components. Each time this trip is made, a mounting operation is completed, that is, a mounting cycle is completed. Generally, the mounting cycle of CHIP components in high-speed machine mounting is within 0.2s, and the current maximum mounting cycle is 0.06-0.03s. - The mount cycle of machine mount QFP is 1 ~2 s, and the mount cycle of Chip component is 0.3 ~ 0.6 s.
II. Placing rate of SMT machine
Mount ratio refers to the number of mount components within 1 hour, unit is c/h. The mounting rate is the mounting speed measured by the manufacturer of the mounting mechanism under ideal conditions. The calculation of theoretical speed does not consider the loading and unloading time of PCB. The patch is closest and only a small number of components are attached (about 150 chip components). Then the time taken to attach one component is calculated, and the number of mounts in 1 hour is calculated accordingly.
III. Support time on SMT patch production line
1. The loading/unloading time of PCB is usually 5 ~ 10 s for the mounting machine.
2. large (rectangular)PCB components are far away from each other, the patch time will be extended.
3. refueling time.
4. machine maintenance time (day/week/month), this is the advantage of good quality SMT machine, good quality can reduce the machine maintenance time.
5. Unpredictable downtime.
Actual patch SMT placement machine speed is far lower than theory patch, usually about 65% of the theory of patch speed - 70%, this is SMT machine or the choose and buy when calculating placement machine production capacity problems should be considered.
