Borey Advanced - How to Calculate the Actual Placement Speed of SMT Mounters

2024-01-17


There is a certain gap between the actual SMT mounting speed and the theoretical mounting speed provided by the mounting machine manufacturer. We all know that the SMT placement speed of the SMT placement machine determines the production capacity of the placement machine and the production line, and is an important limiting factor of the entire production line capacity. So how is the actual SMT mounting speed calculated?

1、 The installation cycle of SMT mounting machine

The installation cycle is the most basic parameter that indicates the installation speed. It refers to the time it takes to start from picking up the component, detect it, place it on the PCB, and then return to the picked component position. Every time this journey is carried out, one installation operation is completed, that is, one installation cycle is completed. The installation cycle for Chip components on general high-speed machines is within 0.2 seconds, and currently the highest installation cycle is 0 06-0 03 s- The installation cycle of machine mounted QFP is generally 1-2 seconds, and the installation cycle of Chip components is 0.3~0 6 seconds.

2、 The installation rate of SMT mounting machine

The installation rate refers to the number of components installed within 1 hour, measured in c/h. The installation rate is the installation speed calculated by the SMT machine manufacturer under ideal conditions. The calculation of theoretical speed does not take into account the PCB loading and unloading time. The placement distance is the closest and only a small number of components (about 150 chip type components) are placed. Then, the time required to install one component is calculated, and the number of installations per hour is calculated based on this.

3、 Auxiliary time on SMT surface mount production line

1. PCB loading/unloading time, usually takes 5-10 seconds for SMT machines.

2. The distance between the components on large (rectangular) PCBs is relatively long, which will prolong the SMT time.

3. Refueling time.

4. The maintenance time of the machine (days/weeks/months) is the advantage of a high-quality SMT mounting machine. A SMT mounting machine with good quality and no malfunctions can reduce the maintenance time of the machine.

5. Unpredictable downtime.

The actual mounting speed of SMT mounting machines is much lower than the theoretical mounting speed, usually about 65% -70% of the theoretical mounting speed. This is a problem that should be considered when selecting or calculating the production capacity of mounting machines.