Circuit board packaging structure

A circuit board packaging structure comprises a plurality of circuit boards disposed in parallel to each other and each packaged with electric circuit parts. The circuit board packaged with electric circuit parts exhibiting a larger exothermic quantity than those of the electric circuit parts packaged on the other circuit boards is disposed outermost among the plurality of circuit boards. The surface of the circuit board packed with the electric circuit parts exhibiting the larger exothermic quantity is directed outside the structure.

What is claimed is:

1. A circuit board packaging structure comprising:

a plurality of circuit boards each packaged with electric circuit parts and disposed in parallel to each other, wherein a circuit board packaged with electric circuit parts exhibiting a larger exothermic quantity than those of the electric circuit parts packaged on other circuit boards of said plurality of circuit board is disposed outermost among said plurality of circuit boards and, at the same time, disposed so that the surface of the circuit board packed with the electric circuit parts exhibiting the larger exothermic quantity is directed outside;

a first cooling fan for flowing cooling air from outside of the structure along said plurality of circuit boards to cool off the electric circuit parts packaged on said plurality of circuit boards; and

a second cooling fan for pulling said cooling air in a direction from said first cooling fan along said circuit board toward the outside of the structure.

2. A circuit board packaging structure according to claim 1, wherein the electric circuit parts include a transmission line corresponding unit of a switching equipment for accommodating a plurality of transmission lines and, at the same time, processing the data from each transmission line on a packet-basis.

3. A circuit board packaging structure according to claim 2, wherein said electric circuit parts are separated into a plurality of individual units, individually connected respectively to the plurality of transmission lines accommodated therein for individually processing packets, and separated into a common unit for batch-processing the packets processed by said individual units, each of said individual units and said common unit being mounted on a respective one of said plurality of circuit boards.

4. A circuit board packaging structure according to claim 3, wherein the electric circuit parts exhibiting the larger exothermic quantity are electric circuit parts constituting said common unit.

5. A circuit board packaging structure according to claim 4, further comprising another common unit, said two common units each having the same construction and provided respectively for active operation and standby operation.

6. A circuit board packaging structure according to claim 5, wherein said two common units are respectively packaged on separate circuit boards of said plurality of circuit boards, and

said circuit boards packaged with said common units are disposed at both ends of said plurality of circuit boards.

7. A circuit board packaging structure according to claim 6, wherein said plurality of circuit boards are connected to a same connecting board, and

an outer surface of said connecting board is provided with wires for connecting said common unit to each of said individual units.

8. A packaging structure of a circuit board according to claim 7, wherein said circuit boards packaged with said common units are connected to said connecting board in a rotationally symmetrical arrangement about an axis orthogonal to said connecting board, and

said wires provided on the outer surface of said connecting board having the same rotational symmetry as that of said respective common units.

9. A circuit board packaging comprising:

a plurality of circuit boards each packaged with electric circuit parts and disposed in parallel to each other, wherein a circuit board packaged with electric circuit parts exhibiting a larger exothermic quantity than those of the electric circuit parts packaged on other circuit boards of said plurality of circuit board is disposed outermost among said plurality of circuit boards and, at the same time, disposed so that the surface of the circuit board packed with the electric circuit parts exhibiting the larger exothermic quantity is directed outside;

a first cooling fan for flowing cooling air along said plurality of circuit boards to cool off the electric circuit parts packaged on said plurality of circuit boards;

a plate for collecting cooling air from said first cooling fan, bended to gather air, disposed outside of said circuit board packed with the electric circuit parts exhibiting the larger exothermic quantity; and

a second cooling fan for blowing said cooling air from said first cooling fan against said circuit board disposed outermost among said plurality of circuit boards from a direction perpendicular to said circuit board to cool off said electric circuit parts exhibiting the larger exothermic quantity, mounted on said plate.