- PP4 -
SMD-Pick and Place Machine and Paste Dispenser
This project is now mainly finished.
More details on the current state are available on the project news page.
- All linear rails are made by HiWin. The X- and Y axis are driven by BLDC-Servomotors with 2000 imp/rev (500imp/rev in X4 mode) rotary encoders. The movement is transmitted using HDT5 timing belts. Reference points for all linear rails are determined using mechanical switches.
- The first Z-axis (Z1) moves the placement head up and down. It hangs upon a piece of 2.5mm pitch timing belt that is wound up using a stepper motor with a pulley. Movement in downward direction is done by gravity. The first rotational axis (A1) uses a hollow shaft stepper motor. Nozzles are held using magnetic force. Nozzles can be automatically changed using a nozzle reservoir with three positions.
- The second Z-axis (Z2) is used to dispense paste. Its principle of linear movement is the same as for the first Z-axis. It moves a syringe up and down that contains the paste. The paste is moved out of the syringe using a linear drive stepper motor that moves a lead screw.
- All stepper motors are moved in 1/16 step mode.
- The vacuum that is used to hold the components onto the nozzle is created using a modified aquarium pump. The short pressure puff needed to place the parts is generated using an air compressor with a pressure regulator. The vacuum level when a part is lifted is controlled using a vacuum sensor that is mounted onto the placement head.
- A camera with LED lightning that is mounted onto the placement head and is used to find fiducial marks on the PCB and to do a visual placement check after placement has been finished. Another camera mounted onto the machine bed is used for part alignment. Its lightning can be switched between red and green color. Both cameras are USB cameras (Microsoft LifeCam Cinema). Their electronic components are separated from their case.
- The machine bed offers enough room for the PCB and parts that are delivered in trays and parts in cut tape strips. Additionally a vibratory feeder is mounted onto the machine bed.
- A 3D-PDF document of the whole machine is available here for download. To rotate and zoom the model, it is necessary to use the original Adobe-Reader.
- The device is controlled using an internal controller PCB. The main CPU is a Microchip PIC 32bit type. Connection to the PC is done via USB using a FTDI chip. The X- and Y axis are controlled using the UPCX530 BLDC controller. The stepper motor drivers are implemented using a TB6560AHQ made by Toshiba. Movement calculation uses a 3rd order movement profile.
- Other PCB's can be found near the BLDC motors and on the placement head.
- Separate controllers for the automatic tape feeders use a small dsPIC to control up to 20 slots each.
The software is written using Embarcadero Delphi XE4. The vision section uses openCV and the Delphi port of its library headers written by "Laex" (https://github.com/Laex/Delphi-OpenCV). The separate scripter program and the separate "CAD" program use commercial Delphi components available from TMS-Components.
Please use the left menu (or at the bottom on portable devices) for more details.