Hi everyone, long time reader, first time poster.
Back on topic, the "heart" of all electronics in all F1 cars is TAG-310B
(PDF File). (not sure if they use 310B, 210 or 400 module)
As McLaren state, its power consumption when operational is about 40W (~14Vdc/~3Adc) and the internal temperature should not increase 70 deg C. It is not an easy task to accomplish this even it is not heated by other car internals, its cooling is obligatory.
The MPU they use, i believe, is PowerPC 476FP
, and for the tasks it is designed, is better than any PC-processor (they are different though). As I can see, they use some weird method for programming - "Application code is autocoded using our Graphical Development Environment (GDE) from Matlab/Simulink control modules." - this adds some overhead for both code and time (this means a directly programmed less powerful MPU should be capable of doing exactly the same work), but the benefit of using their system is that they can change the firmware very fast without the need of highly experienced software developers with thorough knowledge in engine and transmission control.
But there are other electronic units that require cooling (well, may be not all of them), for example ingnition and injection modules: IGN310
In general, electronic components are divided into temperature grades, with general purpose grade 0-70 deg C (rarely used), industrial grade (-20 to 105/125 deg C - lower and upper limits vary upon manufacturer and part), and military grade (-40/60 to +150/+175 - again vary upon manufacturer and part). I doubt if they use anything else than military grade components. Any decent electronic device should be capable of working at 100 deg C, but keep in mind, that the crystal temperature of every heatsink-mounted semiconductor is at least 5 to 20 deg C (and may be more, depending on the design) more than the temperature that you can measure on the heatsink surface.
The design of the unit would be closer to military spec in hardware especially the wiring. Vibration/Shock design of the internal board(s) is of a very high level for obvious reasons. Thicker PC boards and surface mount technology in use here (as you can see from the PC board picture posted)
Though the processor may not be as highly functional or powerful as the new Intel or AMD processors as one might think. They don't need to be, as their job isn't as expansive as a desktop or a laptop. The processor mainly needs to function in math calculations and equation comparisons. In most cases doing calculations in a "3D" graphical form (for instance drawing from a lambda number through the rpm range with values at every 100rpm and comparing to an ignition map at the same time with similar values of rpm) and most ECU's have logging capability, which also doesn't tax a processor and is essentially a recording volt meter (Does need an A_to_D conversion processor however).
The "worst" period of time for the electronics is when a hot car pulls into the pits and has to sit for a length of time. The body panels contain the built up heat and will reach the max that the systems will ever see. This why you will see fans put into the radiator ducting, not so much for the radiator cooling but for cooling off the chimney effect of the exhaust and engine components. Most of the time if the car is going to sit for a length of time, you will see them remove the engine cover for this very reason.
With no fueling this year and short stops for tires, this will help remove this problem. But will create a new one, running the for a lengthy time (building a higher heat level).
"Driving a car as fast as possible (in a race) is all about maintaining the highest possible acceleration level in the appropriate direction." Peter Wright,Techical Director, Team Lotus