Turn-key PCB assembly services in prototype quantities or low-volume to mid-volume production runs

PCB etching thermostat

Probably many hobbyists doesn’t care much about etching solution temperature when etching PCBs. In fact warm enough liquid does job well. But if you want to be more accurate and make process more smooth and predictable then use a thermostat to control heater. This is a thermostat uses a NTC sensor that is connected to PIC 16F256 microcontroller and depending on temperature value the relay is switched ON or OFF. Temperature value is also displayed on 2×7 segment display so overall design is pretty low budget and does the job very well for task like controlling PCB etcher heater. Current firmware has temperature thresholds set to 38 and 42°C, so if you need different values you need to change two constants in source code and recompile it, or simply modify a project a little and add couple buttons to make it more flexible. Continue reading

Reflow Soldering Oven controller with graphical LCD Display

One of SMD soldering techniques is using a reflow soldering oven. Reflow soldering technique is used when it is impossible to solder components by hand. These may include ball grid arrays (BGA), small pitch quad flat packs. Or simply solder any SMD element to make board look professional and smooth. Special care has to be taken when soldering with oven. Specialized ovens have controllers built in that control overall soldering process by adjusting temperatures, but if you are using regular oven that is much cheaper than specialized soldering ovens, you need to build a controller. Controller has to adjust soldering oven temperature according to chart that is stored in memory. Together with keypad this gives great interactivity. Soldering oven controller is based on ATmega32 microcontroller that uses ADC input to read NTC temperature sensor. Current temperature is displayed on graphical LCD as chart. As authors state – system works OK, maybe additional blower could be added for cooling speed controlling as without fan it is to slow. Continue reading