These days many of the maximum "exiting" chips come handiest in leadless programs, consisting of bga and qfn which might be tough or impossible to solder simply by soldering iron,reflow oven Malaysia because leads are below the chip in which they cannot be reached. Those varieties of chips are typically soldered the usage of reflow soldering. In reflow process solder paste is used in preference to solder wire. It contains very small balls of solder in flux, diameter of the balls is just few micrometers. First this paste is put on the touch pads, then additives are located at the pads and entire board is heated in reflow oven where solder balls within the paste soften and attaches the components firmly in location. Temperature profile in reflow soldering. Source: wikipedia

for the solder paste to paintings effectively temperature of the oven must observe accurate temperature profile as it should be. If the temperature rises too speedy it can harm the additives and if the temperature rises too slowly, too much flux can evaporate and the additives aren't soldered reliably. Actual reflow ovens are commonly highly-priced, like many other manufacturing gear, however ordinary toaster ovens can be used in reflow soldering with few modifications. They're plenty less expensive than real reflow ovens, but temperature cannot be set programmatically or appropriately. Outside controller board can be used to govern those ovens. Reflow oven controller

toaster oven reflow controllers had been executed before typically (for example 1 and a pair of). I desired to make a simple and reasonably-priced controller that would not use previous parts. In preference to buttons and dedicated show, it ought to use usb port for placing the temperature profile and monitoring the temperature if wished. This would be inexpensive to make and smooth to apply. If the pc is not related, it ought to be able to be switched on with the aid of simply connecting the strength deliver, load the temperature profile from non-volatile reminiscence and run without consumer intervention. Due to the fact the oven receives particularly warm, it's no longer possible to feature any electronics inner it. Controlling is carried out through switching the electricity on and rancid rapidly with solid country relay that is linked on extension wire.

Temperature is measured the usage of thermocouple in the oven. Microcontroller will study the temperature and output pwm signal for the strong state relay which can be used to as it should be manipulate the temperature of the oven. 1380w toaster oven with convection. Offered 2nd hand for 20€. I determined to use atmega8u2 microcontroller, because i am familiar with avrs and this is the most inexpensive avr with hardware usb assist. Because oven can get pretty warm i had to use thermocouple for measuring the temperature, in place of cheaper temperature sensors ics.

I take advantage of max31855 as a thermocouple-to-virtual converter. This is the most highly-priced aspect within the board costing 6. 21€ at digikey, even the strong nation relay from dealextreme turned into less expensive costing best 5. 08€. Regrettably i made a few mistakes with the pcb and wired the usb connector pins in reverse order. One hint became additionally left in part unrouted, after i accidentally removed part of it in eagle earlier than producing the gerber files. I did not have tools to restoration the usb connector lines, so i simply reduce them out and soldered an usb cable on the board. Lacking trace became replaced with enameled wire.click here