Mainboard PCB Design
If a desktop mainboard is not free from some design flaws, this drawback can sometimes be compensated by its additional functionality. However, if the layout of a barebone mainboard is not designed in the most optimal way, it can be crucial for the verdict about this board. In a small form-factor case inconveniently located connectors, cables running through the whole system and components staying outside the cooling airflow may turn into a serious problem. Moreover, all this may cause some problems during the system assembly that is why we considered it very important to pay special attention to the PCB layout of our Soltek SL-B9D-FRG mainboard used inside the Qbic EQ3901M system.
When you cast a glance at our mainboard you will be able to tell right away that Soltek engineers did a great job. All electronic components are located at a certain distance from one another, so that there won’t be too overheated spots on the mainboard. All jumpers are placed close to the PCB edges, so you will not have to dig your way through all the cables inside the case, once you need to adjust the jumper settings in the assembled system. I could say even more good things about this board, but let me start from the very beginning.
First come different ports and connectors. All of them are split into two groups: one is located at the front edge of the mainboard (the edge closer to the barebone front panel), and another one is at the back edge of the mainboard. Most connectors in the back are those that lead to the mainboard back panel (we have already listed them when we were talking about the barebone features). Also there you will find CDIN1 and LPT1 connectors for the audio port of the optical drive and parallel port connector respectively. The connectors in the front include connectors for PATA and SATA devices, FDD, 2 connectors for USB ports (two ports per connector) and an IEEE1394 connector. Also there is a connector for additional audio jacks and a connector for system LEDs and switches. Of course, we shouldn’t forget the power supply connectors in the front left corner of the mainboard. Besides, there is a connector for an additional system fan next to the FDD connector, although there is no fan in the system.
The memory slots are placed along the right side of the mainboard. The main system fan is the one responsible for removing hot air from them. The AGP and PCI slots are located at the left side of the mainboard PCB. The processor socket is located between the DIMM and PCI slots. In the assembled system there is a PSU fan right above the CPU socket that is why the CPU is cooled down pretty efficiently, and the warm air doesn’t stay there long.
All add-on controller chips and AC’97 codec are laid out in the area between the processor socket and the mainboard back panel. Next to the processor socket you can see a BIOS chip and CMOS memory battery. Both chipset bridges are placed between the CPU and the front edge of the mainboard, and they are both equipped with a passive heatsink.
Among the unused features I should mention the IR port, one of the USB connectors, and Fan 3.
Summing up I can conclude that the mainboard is designed in a very optimal way, and to tell the truth it would be hard to think of a better solution in this case.