After using SMT laser stencil printing, you need an SMT placement machine to mount. There are many types of placement machines, which are specifically divided into the following types:

Frame type

The component feeder and the substrate (PCB) are fixed, and the placement head (installed with multiple vacuum suction nozzles) moves back and forth between the feeder and the substrate, and the components are taken out from the feeder. After adjusting the position and direction of the components, then Paste on the substrate. Because the patch head is installed on the X/Y coordinate moving beam of the arch type, it is named.

The adjustment method of the position and direction of the components of the arch mounter:

1) Adjust the position by mechanical centering and adjust the direction by rotating the suction nozzle. This method can achieve limited accuracy, and it is no longer used in later models.

2) Laser recognition, X/Y coordinate system adjustment position, suction nozzle rotation adjustment direction, this method can realize the identification during the flight, but it cannot be used for the ball grid display component BGA.

3) Camera identification, X/Y coordinate system adjustment position, suction nozzle rotation adjustment direction, generally the camera is fixed, and the placement head flies across the camera for imaging identification, which takes a little longer than laser identification, but it can identify any component, and there are also The camera recognition system that realizes the recognition during the flight has other sacrifices in terms of mechanical structure.

In this form, the speed is limited due to the long distance that the placement head moves back and forth. Generally, multiple vacuum suction nozzles are used to pick up materials at the same time (up to ten) and a double-beam system is used to increase the speed, that is, the placement head on one beam is picking up materials, while the placement head on the other beam is placing components. , almost twice as fast as the single-beam system. However, in practical applications, it is difficult to achieve the condition of taking materials at the same time, and different types of components need to be replaced with different vacuum suction nozzles, and there is a time delay in changing the suction nozzles.

The advantages of this type of machine are: the system structure is simple, it can achieve high precision, it is suitable for components of various sizes and shapes, even special-shaped components, and the feeders are in the form of strips, tubes, and trays. It is suitable for small and medium batch production, and can also be combined with multiple machines for mass production.

Turret type

The component feeder is placed on a single-coordinate moving feeder, the substrate (PCB) is placed on a worktable that moves in an X/Y coordinate system, and the placement head is installed on a turret. When working, the material feeder puts the component feeder Move to the pick-up position, the vacuum suction nozzle on the patch head picks up the components at the pick-up position, and rotates to the pick-up position through the turret (180 degrees from the pick-up position). Adjust and place the components on the substrate.

Adjustment method for component position and direction:

1) Adjust the position by mechanical centering and adjust the direction by rotating the suction nozzle. This method can achieve limited accuracy, and it is no longer used in later models.

2) Camera identification, X/Y coordinate system adjustment position, suction nozzle self-rotation adjustment direction, fixed camera, placement head flying across the camera for imaging identification.

Generally, more than a dozen to twenty patch heads are installed on the turret, and each patch head is equipped with 2~4 vacuum nozzles (earlier models) to 5~6 vacuum nozzles (existing models) . Due to the characteristics of the turret, the actions are miniaturized, such as selecting and changing the suction nozzle, moving the feeder in place, picking up components, component recognition, angle adjustment, worktable movement (including position adjustment), and placing components can all be performed in the same time period. It is completed within, so it achieves high speed in the true sense. At present, the fastest time period reaches 0.08~0.10 seconds for one component.

This model is superior in speed and is suitable for mass production, but it can only use tape-packed components. If it is a dense-foot, large-scale integrated circuit (IC), it cannot be completed with only tray packaging, so it is still available. Depends on other models to work together. This kind of equipment has complex structure and high cost. The latest model is about US$500,000, which is more than three times that of the arch type.

constitute

At present, there are many types of placement machines, but whether it is a fully automatic high-speed placement machine or a manual low-speed placement machine, its overall layout is similar. The automatic placement machine is controlled by a computer and is a high-precision automation equipment integrating optics, machinery and electronics. The recognition system consists of sensors and computer control systems, which realize the rapid and accurate placement of SMD components through functions such as pick-up-displacement-position-placement.

frame

The frame is the foundation of the machine, and all the transmission, positioning mechanisms and feeders are firmly fixed on it, so it must have sufficient mechanical strength and rigidity. At present, there are various types of racks for placement machines, mainly including overall casting type and steel plate welding type. The first type has strong integrity, good rigidity, small deformation, and stable operation, and is usually used in high-end machines; the second type has the characteristics of simple processing and low cost. The specific structure of the frame for the machine depends on the overall design and load-bearing of the machine, and it should be stable, relaxed, and vibration-free during operation.

PCB Transfer and Carrying Organization

The transmission mechanism is an ultra-thin belt transmission system placed on the guide rail. Usually, the belt is installed on the edge of the track. Its function is to send the PCB to the predetermined position, and then send it to the next process after placement. The transmission mechanism is mainly divided into two types: integral type and segmented type. In the integral type, the entry, placement and delivery of the PCB are always on the same guide rail. The limit block is used to limit the position, the positioning pin is positioned upward, and the compression mechanism compresses the PCB. Tight, the support bar on the support plate moves up to support to complete the positioning and fixing of the PCB. The positioning accuracy of the positioning pin is low, and the optical system can also be used when high precision is required, but the positioning time is longer. Segmented type is usually divided into three sections. The first section is responsible for receiving the PCB from the upper process, the middle end is responsible for positioning and pressing the PCB, and the latter section is responsible for sending the PCB to the next process. Its advantage is to reduce the PCB transfer time.

drive system

The drive system is the key structure of the placement machine, and it is also an important indicator for evaluating the accuracy of the placement machine. It includes the XYZ transmission structure and the servo system, and its functions include supporting the movement of the placement head and supporting the PCB load-bearing level.

Send us an inquiry , we will get back to you soon ,thank you !