Applications and Implications

Final project planning for: SMT Pick and place machine

What will it do?

The machine will pick a smd device from a dispenser and place it on a pcb. The purpose is to automate the stuffing of the circuit boards, enhancing precision and confiability, and saving time also.

Who has done this before?

There are commercial machines (which are expensive) and also DIY machines.This machine is in the concept of the MTM machines, ie low cost machines that can be made with the tools available in a Fab Lab. By the type construction this machine is also known as MTM snap.

Figure 1. Commercial (1st and 2nd) and DIY pick and place machines (Red frog DIY PnP Machine)

What materials and components will be used?

The machine cabinet is based in the MTM machine snap lock system, we have changed the form of the cabinet (proposed in assignment 2) to allow ease of positioning of the board to be assembled, it also will have a dispenser for the components, as shown in the computer design assignment. The dispenser will be printed with the 3D printer as shown in the week assignment.

The prototype cabinet will be manufactured in MDF (Medium Density Fiberboard) and for the final cabinet we will use probably HDPE (High Density Polyethylene)

Figure 2. Cabinet and dispenser as proposed in assignments 2 (computer aided design) and 9 (3D scanning and printing)

The z axis will hold a pick and place tool which is build with a hypodermic syringe, wire spring and a vacuum pick up tip.

Figure 3. Pick and Place tool build with a syringe, a wire spring and a vacuum pick up tip

For the X-Y-Z movement, we will use stepper motors, these motors will be drived by an electronic controller made with the Allegro A3982 Stepper controller, following the design of the Arduino shield for the MIT MTM. We will also use an Arduino for developing the program and once the program is finished we expect change it by a Fabduino like the designed by Andy Bardagjy Anduino.

Where will they come from?

We planned to buy locally some of the mechanical components and materials, but we couldn't got them with the necessary tolerances, although we are going to use them in the prototype. All the electronic components must be imported also.

I include the complete bill of materials PnP Machine BOM

How much will it cost?

It will cost about $600 Dollars with imported components. After finishing the project we can establish what components could be replaced by local components in order to reduce the cost.

What parts and systems will be made?

The following parts will be made

• The cabinet for the X-Y-Z movement and the tool base

• The dispenser

• The pick and place tool

• The Arduino's electronic shield for motors control

• The program for the machine control

What processes will be used?

• Mechanical and Machine designs

• Computer Controlled Machining for the cabinet

• 3D printing for the dispenser

• Electronics Production for the board and assembly of the control system

What tasks need to be completed?

• Cabinet manufacturing

• Arduino shield for driving the stepper motors

• Pick and place tool base

• Make the program

What questions need to be answered?

• How to load the position of the electronic components to the program?

• How to improve the suction of the pick and place tool?

What is the schedule?

Machine design: To be finished on May 22

Manufacturing and assembling the cabinet: May 23 to May 25

Manufacturing and assembling the electronics: May 26 - 27

Making the program: May 25 to May 28

Final test: May 29

How it will be evaluated?

It will be evaluated by the following:

• Three axis movement to position the tool to pick the component
• Move the tool with the component to its position on the board
• Place the component on the board

Final comments

We are on the way to the goal