User Guide Reflow Toaster Oven Controller Version 1.5-01/10/12 DROTEK Web shop: www.drotek.fr
SOMMAIRE 1. Introduction... 3 2. Preparation of THE REFLOW CONTROLLER... 4 2.1. Power supply... 4 2.2. USB connector... 4 2.3. Thermocouple... 5 2.4. LCD Display... 6 2.5. Connection between the main and second board... 7 2.6. Buzzer... 8 2.7. Push buttons... 8 2.8. LED... 9 3. Configuration of the reflow profile... 10 3.1. Setup menu... 10 4. Steps of the reflow process... 12 4.1. Preheating... 12 5. Human Machine Interface (HMI) Software... 14 Référence : Indice : Page 2 sur 15
1. INTRODUCTION Reflow soldering is a process in which a solder paste (a sticky mixture of powdered solder and flux) is used to temporarily attach one or several electrical components to their contact pads, after which the entire assembly is subjected to controlled heat, which melts the solder, permanently connecting the joint. Heating may be accomplished by passing the assembly through a reflow oven or under an infrared lamp or by soldering individual joints with a hot air pencil. Reflow soldering is the most common method of attaching surface mount components to a circuit board. The goal of the reflow process is to melt the solder and heat the adjoining surfaces, without overheating and damaging the electrical components. In the conventional reflow soldering process, there are usually four stages, called "zones", each having a distinct thermal profile: preheat, thermal soak (often shortened to just soak), reflow, and cooling. Référence : Indice : Page 3 sur 15
2. PREPARATION OF THE REFLOW CONTROLLER 2.1. Power supply The card operates under a DC supply voltage between 6V and 12V. The consumption is very low. Figure 1 - power supply connector You can use a wall adaptor or a clip for 9v battery (option: sold on the web shop). 2.2. USB connector Référence : Indice : Page 4 sur 15
When the REFLOW CONTROLLER is power supplied and when the green LED is blinking, the temperature of the thermocouple is sent to the PC via the USB port. The configuration of the USB port is: - Speed (baud) = 9600 - Data bits = 8 - Stop bits = 1 - Parity = None 2.3. Thermocouple The thermocouple has to connect to the blue terminal block. Figure 2 - thermocouple on blue terminal block If when the oven heats, the temperature displayed on the LCD decrease, it means that the thermocouple is connected in reverse. Kindly reverse the two ends of the thermocouple located in the blue terminal. The thermocouple shall be placed at the bottom of the oven. Référence : Indice : Page 5 sur 15
2.4. LCD Display Figure 3- before assembly Figure 4 - after assembly Référence : Indice : Page 6 sur 15
2.5. Connection between the main and second board Warning: we cannot be held responsible for any damage caused by this kit. The presence of high voltage on this card can be extremely dangerous and cause death. We do not recommend this kit to anyone who is not familiar with electronics. The 5v, GND and signal pins of each board have to be connected together. The phase wires of the power supply cable and the oven cable have to be cut and connected to the red board like represented on the picture below. Figure 5 connection Référence : Indice : Page 7 sur 15
2.6. Buzzer The buzzer can alert the user when the reflow cycle is complete and the oven door must be opened to allow cooling of the PCB. It can be disabled in the setup menu. Figure 6 - buzzer 2.7. Push buttons The reflow controller has 3 push buttons that can run the reflow, navigate the menu, set variables and the reflow profile. It is important to note that the PB3 button can stop the reflow Emergency. Figure 7 - push buttons Référence : Indice : Page 8 sur 15
2.8. LED The blue LED indicates that the card is powered. The green LED is blinking at each time the card send the temperature to the PC via the serial port COM. The red LED lights when the relay is activated and therefore when the oven heats. Figure 8 - blue, green and red LED Référence : Indice : Page 9 sur 15
3. CONFIGURATION OF THE REFLOW PROFILE Once the card is started, two choices available to you. Either you press the PB1 button to configure the reflow profile, or you press the PB2 button to start the cycle reflow. Figure 9 - display 3.1. Setup menu Once you pushed the PB1 button, the display below appears and you have 3 possibilities. - PB1 = left the setup menu and flashing the EEPROM - PB2 = configure the variable Preheat degree - PB3 = go to the next variable of the setup menu Figure 10- first variable of the setup menu If you press the PB1button, this display appears: Figure 11 - flashing eeprom Référence : Indice : Page 10 sur 15
If you press the PB2 button, the display below appears and you have 3 possibilities. - PB1 = decrease the temperature of the Preheat variable - PB2 = back to the setup menu - PB3 = increase the temperature of the Preheat variable Figure 12 - temperature If you press the PB3 button several times, the last variable of the setup menu appears and you have 3 possibilities. - PB1 = go to the previous variable of the setup menu - PB2 = configure the variable Cooling degr Max - PB3 = left the setup menu and flashing the EEPROM Figure 13 - last variable of the setup menu If you press the PB2 button PB2, the display below appears and you have 3 possibilities. - PB1 = decrease the time of the Cooling variable - PB2 = back to the setup menu - PB3 = increase the temperature of the Cooling variable Figure 14 - secondes Référence : Indice : Page 11 sur 15
4. STEPS OF THE REFLOW PROCESS If you want to launch the reflow, you have to press the PB2 button at the beginning and wait. 4.1. Preheating The relay opens, the red LED lights and the oven heats. The rise in temperature will not exceed the variable Preheat Temp Max that you have set in the setup Menu. Figure 15 - preheating Once the preheating temp temperature reached, the microcontroller will control the temperature during soaking time seconds to reach the soaking temp temperature. Figure 16 - soaking Once the soaking temp temperature exceeded, the oven will heat up until it reaches the reflow temperature. Figure 17 - reflow Référence : Indice : Page 12 sur 15
Then the temperature will remain constant for a time defined in the setup menu. Now opening the oven door is requested and the buzzer sounds until the temperature decrease (the buzzer can be disabled in the setup menu). Figure 18 - open the door The cooling temperature will not exceed the Cooling degr Max temperature. Figure 19 - cooling Once the oven has cooled, the screen below appears. The reflow process is finished and the components of your PCB are soldered! Figure 20 - the end Référence : Indice : Page 13 sur 15
5. HUMAN MACHINE INTERFACE (HMI) SOFTWARE The HMI software is able to display the temperature of the thermocouple in real time. The reflow controller sends the temperature via the serial port COM. The picture below is a screenshot made during a reflow process. The setpoint temperature is represented by red lines. I will let you observe the accuracy of the result. Have fun... Figure 21- HMI Référence : Indice : Page 14 sur 15
Figure 22 - setpoint temperature Référence : Indice : Page 15 sur 15