The placement machine provides highly flexible programming capabilities, so that the operator can adjust the placement mode according to SMT components with different BIN values to ensure the uniformity of the end product. Let me share with you what types of sensors of the placement machine?
1. Mounter pressure sensor
In the placement machine, including various cylinders and vacuum generators, there are certain requirements for air pressure. When the pressure is lower than the pressure required by the equipment, the machine cannot operate normally. The pressure sensor always monitors the pressure change. Once abnormal, it will alarm in time to remind the operator to deal with it in time.
2. Mounter negative pressure sensor
The suction nozzle of the placement machine sucks components by negative pressure, which consists of a negative pressure generator (jet vacuum generator) and a vacuum sensor. If the negative pressure is not enough, it will not be able to absorb the components. When the feeder has no components or the components are stuck in the material bag and cannot be sucked up, the suction nozzle will not be able to absorb the components. These situations will affect the normal operation of the machine.
The negative pressure sensor always monitors the change of negative pressure. When there is a situation where it cannot absorb or absorb components, it can alarm in time to remind the operator to replace the feeder or check whether the suction nozzle negative pressure system is blocked.
3. Mounter position sensor
The transmission positioning of the printed board, including the counting of the PCB, the real-time detection of the movement of the placement head and the table, and the movement of the auxiliary mechanism, all have strict requirements on the position, and these positions need to be realized by various forms of position sensors.
4. Mounter image sensor
The real-time display of the working status of the placement machine mainly uses a CCD image sensor, which can collect various required image signals, including PCB position, device size, and analyze and process it by computer, so that the placement head can complete the adjustment and placement work.
5. Mounter laser sensor
Lasers have been widely used in placement machines to help determine the coplanarity of device pins. When the device under test runs to the monitoring position of the laser sensor, the beam emitted by the laser irradiates the IC pin and is reflected to the laser reader. If the length of the reflected beam is the same as the emitted beam, the device coplanarity is qualified. When they are not the same, the reflected light beam becomes longer due to the upturn of the pins, and the laser sensor recognizes that the pins of the device are defective.
Likewise, the laser sensor can also identify the height of the device, which can shorten the production lead time.
6. Mounter area sensor
When the placement machine is working, for the safe operation of the placement head, a sensor is usually installed in the moving area of the placement head, and the photoelectric principle is used to monitor the running space to prevent damage caused by foreign objects.
7. SMT component inspection
Component inspection, including feeder feeding and component type and accuracy inspection. In the past, it was only used in high-end placement machines, and now it is also widely used in general-purpose placement machines. It can effectively prevent components from being misplaced, misplaced, or not working properly.
8. SMT head pressure sensor
With the improvement of the placement speed and accuracy, the requirements for the "suction and release force" of the placement head to place the components on the PCB are getting higher and higher, which is commonly referred to as the "Z-axis soft landing function". It is realized by Hall pressure sensor and load characteristic of servo motor.
When the component is placed on the PCB, it will be vibrated at the moment, and its vibration force can be transmitted to the control system in time, and then fed back to the placement head through the control of the control system, so as to realize the Z-axis soft landing function.
When the patch head with this function is working, it feels smooth and light. If you further observe, the depth of the two ends of the component immersed in the solder paste is roughly the same, which is also very beneficial to prevent welding defects such as "tombstone". The placement head without the pressure sensor will shift and cause the phenomenon of flying.