Many people may not knowhow to use the placement machine , the principle explanation of the placement machine and the safe operation. Today I will share with you the working principle and safe operation process of the placement machine .

SMT machine : also known as placement machine and surface mount system (Surface Mount System). In the production line, it is equipped after the dispensing machine or screen printing machine. It uses a moving placement head to place surface mount components on the surface. A device placed on a PCB pad. The placement machine is a combination of mechanical, electrical, optical and computer control skills. Through suction, displacement, positioning, placement and other functions, SMC/SMD components can be quickly attached to the designated pad position of the PCB without damaging the components and the printed circuit board.

There are three centering methods for mounting components on placement machines : mechanical centering, laser centering and visual centering. The placement machine consists of a frame, xy motion mechanism (ball screw, linear guide, drive motor), placement head, component feeder, PCB carrying mechanism, device alignment detection equipment, and computer control system. The movement of the whole machine is mainly completed by the xy motion mechanism, the power is transmitted by the ball screw, and the directional motion is completed by the rolling linear guide motion pair. This transmission method not only has small movement resistance, compact structure, but also has high transmission efficiency.

1. SMT machines are divided into two types: manual and fully automatic.

2. Principle: The arch-type component feeder and the substrate (PCB) are fixed, and the placement head (equipped with multiple vacuum suction nozzles) moves back and forth between the feeder and the substrate to take out the components from the feeder and process the components. Adjust the orientation and direction, and then place it on the substrate.

3. Because the placement head is installed on an arch-type X/Y coordinate moving beam, it gets its name.

4. Methods for adjusting the component position and direction of the arch-type chip placement machine : 1) Machine centering to adjust the position and nozzle rotation to adjust the direction. This method has limited accuracy and is no longer used in later models.

5. Laser identification, X/Y coordinate system adjustment, and nozzle rotation adjustment direction. This method can achieve identification during flight, but it cannot be used for ball grid display components BGA.

6. Camera identification, X/Y coordinate system adjustment, and suction nozzle rotation and direction adjustment. Normally, the camera is fixed, and the placement head flies over the camera for imaging identification. It takes a little longer than laser identification, but any component can be identified, and it can be completed. The camera recognition system for recognition during flight has other contributions to the mechanical structure.

7. In this method, the speed is limited due to the long interval between the placement head moving back and forth.

8. Generally, multiple vacuum suction nozzles are used to take materials at the same time (up to ten) and a double-beam system is used to increase the speed. That is, while the placement head on one beam is taking materials, the placement head on the other beam is placing materials. The speed of placing components is almost twice as fast as that of a single-beam system.

9. However, in actual application, the conditions for simultaneous material retrieval are difficult to achieve, and different types of components require different vacuum suction nozzles. There is a time delay in changing the suction nozzles.

10. The turret-type component feeder is placed on a single-coordinate moving material cart, the substrate (PCB) is placed on a workbench that moves in the X/Y coordinate system, and the placement head is installed on a turret. During operation, the material The car moves the component feeder to the picking position. The vacuum suction nozzle on the patch head picks up the components in the picking position. It rotates to the patching position through the turret (180 degrees from the picking position). During the rotation, it passes through the alignment Adjust the component position and direction and place the component on the substrate.

11. Adjustment methods for component position and direction: camera identification, X/Y coordinate system adjustment, nozzle rotation adjustment, camera fixed, placement head flying across the camera for imaging identification.

In addition, important components of the placement machine are marked, such as the device shaft, moving/stationary lens, nozzle holder and feeder. Machine vision can automatically calculate the coordinates of these symbol center systems, establish a transformation relationship between the coordinate system of the placement machine and the coordinate system of the PCB and mounted components, and calculate the coordinates of the placement machine . The placement head grabs the suction nozzle and sucks the components to the corresponding position according to the package type, component number and other parameters of the imported placement components; the static lens detects, identifies and centers the components according to the vision processing program; and after completion, the installation head Install the component on the PCB in a predetermined position. A series of actions such as component identification, alignment, detection, and installation are automatically completed by the control system after the industrial computer obtains relevant data according to corresponding instructions.

The placement machine is a device used for high-speed and high-precision placement of components. It is the most critical and complex equipment in the entire SMT production. The placement machine is a chip placement equipment used in SMT production. The SMT machine isplaced in the corresponding position, and then bonded with pre-applied red glue and solder paste, and thenfixed on the PCB through a reflow oven.

The safe operation of the placement machine should comply with the following basic safety rules and procedures:

1. The power should be turned off when inspecting the machine, replacing parts or repairing and making internal adjustments (maintenance of the machine must be carried out with the emergency button pressed or the power supply cut off).

2. When reading coordinates and adjusting the machine, ensure that the YPU (programming unit) is in your hand to stop the machine at any time.

3. Ensure that the interlocking safety equipment remains effective to shut down the machine at any time, and the safety inspection of the machine cannot be exceeded or shortened, otherwise it may easily cause personal or machine safety accidents.

4. During the production process, only one operator is allowed to operate one machine.

5. During operation, ensure that all parts of the body, such as hands and head, are outside the movement range of the machine.

6. The machine must be properly grounded (really grounded, not connected to neutral wire).

7. Do not use the machine in gas or extremely dirty environments.