JP3299447B2 - Back wiring board structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a back wiring board used for connecting a plurality of printed wiring boards in a subrack structure for accommodating a printed wiring board.

[0002]

2. Description of the Related Art Conventionally, in an apparatus in which a plurality of packages are housed in a cabinet to form a circuit, a printed wiring board is housed in a subrack, and a back wiring is used as means for connecting the circuits of each printed wiring board. A wiring board and a press-in contact type connector are used.

FIGS. 7 and 8 show the configuration of a conventional back wiring board. FIG.
FIG. 8 is a sectional view thereof. 7 and 8, reference numeral 51 denotes a back wiring board on which a circuit (not shown) is formed; 52, a printed wiring board; 53, a housing of a connector 54 for connecting the printed wiring board 52 to the back wiring board 51; Press-in contact,
Reference numeral 56 denotes a through hole formed in the back wiring board 51 for press-fitting the press-in contact 55.

In this structure, the press-in contact 55 is pressed into the through hole 56 of the back wiring board 51 to attach the housing 53 to the back wiring board 51, and the press-in contact 55 is connected to the circuit of the back wiring board 51. Then, the connector 54 is fitted into the housing 53, and the printed wiring board 52 is connected to the back wiring board 51.
Attached to. Further, although the number of circuits tends to increase today, when the number of circuits increases, conventionally, the number of circuit layers in the back wiring board has been increased to cope with the increase.

[0005]

However, in the above-mentioned conventional structure, when the number of layers in the back wiring board is increased, the lamination position accuracy of each layer becomes extremely strict and the manufacturing becomes difficult. , Costs increase exponentially. In addition, today, high speed transmission signals require impedance matching, which also requires strict accuracy. For this reason, the substantial circuit scale of the back wiring board is limited, and the present situation is that there is a limit to achieving higher density and lower cost of the device.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to provide a back wiring structure capable of easily realizing high-density circuits at low cost.

[0007]

Means for Solving the Problems The present invention is characterized by taking the following technical means in order to achieve the above object.
That is, a back wiring board structure in which a connector provided with a contact pin press-fitted into a through hole and attached thereto, and a printed wiring board housed in a subrack is attached via the connector, has the through hole. a main back wiring board, along with and a secondary back wiring board having a through hole that support and the through hole of the main back wiring board, the main back
Wiring board and said auxiliary back wiring board
And the length of the contact pins is set to a size that allows the contact pins to penetrate through the through holes of the main back wiring board and press-fit into the through holes of the sub back wiring board. It is configured.

According to this, a sub back wiring board having a circuit formed in the same manner as the main back wiring board is arranged on the main back wiring board surface, and thereafter, the contact pins are press-fitted in common with the main back wiring board and the sub back wiring board. Then, a circuit can be integrated in a necessary part. Therefore, by changing or adding the auxiliary back wiring board, it is easy to change or add circuit components in that part.

[0009]

1 and 2 show an embodiment of a back wiring board structure according to the present invention. FIG. 1 is a schematic perspective view of the back wiring board structure.
FIG. 2 is a sectional view schematically showing a main part of the back wiring board structure. 1 and 2, this structure includes a main back wiring board 1, a sub back wiring board 2, a connector 3, and the like.

More specifically, a circuit (not shown) is formed in the main back wiring board 1 and a through hole 4 is formed. In addition, a circuit (not shown) is formed on the sub-back wiring board 2, and a through hole 5 is formed. In addition,
The circuit formed on the main back wiring board 1 is a basic circuit, and the circuit formed on the sub back wiring board 2 is a circuit that cannot be accommodated in the main back wiring board 1, a circuit added later, Circuits that are changed depending on the application, circuits that should be separated from circuits on the main back wiring board in terms of performance, and the like, and various types of the sub back wiring board 2 are prepared. Therefore, the size of the auxiliary back wiring board 2 may be the minimum size, and is generally formed smaller than the shape of the main back wiring board 1. That is, in the present embodiment, the size of the sub back wiring board 2 is about half the size of the main back wiring board 1. The through-hole 5 is formed corresponding to the size and the position of the through-hole 4.

The connector 3 is used to connect the printed wiring board 6 to the main back wiring board 1 and the sub back wiring board 2, and includes a housing 7 and contact pins 8. Of these, housing 7
Is formed in a box shape with one surface opened by a resin material.
On the other hand, a plurality of contact pins 8 are provided in such a manner as to penetrate the bottom surface 7a of the housing 7 back and forth, and each is fixed to the bottom surface 7a. The size of the contact pins 8 protruding from the bottom surface of the housing 7a is at least equal to or slightly larger than the total thickness of the main back wiring board 1 and the sub back wiring board 2. Is set. Further, the thickness (outer diameter) of the contact pin 8 is substantially equal to or slightly larger than the inner diameter of the through hole 4 and the through hole 5, and the contact pin 8 is formed in the through hole 4 and the through hole 5. Are press-fitted and attached, that is, pins for a press-in contact type.

The connector 3 has contact pins 8
Is press-fitted into the through-hole 4 and press-contacted to the main back wiring board 1, and the through-hole 5 is made to correspond to the contact pin 8 penetrating through the main back wiring board 1 and projecting to the back surface side. When the sub back wiring board 2 is press-contacted, the sub back wiring board 2 can be assembled in a state where the sub back wiring board 2 is stacked on the main back wiring board 1. In the actual assembling operation, when the contact pins 8 of the connector 3 are press-fitted, a method is adopted in which the contact pins 8 are inserted in a state where the main back wiring board 1 and the sub-back wiring board 2 are overlapped with each other and assembled at once. . Further, the connector 9 on the printed wiring board 6 side is fitted to the connector 3 connecting the main back wiring board 1 and the sub back wiring board 2 in this manner, and is housed in a subrack (not shown). The respective printed wiring boards 6 are connected. Thus, the circuits of the printed wiring boards 6 housed in the subrack are connected via the main back wiring board 1 and the sub back wiring board 2.

Therefore, in this structure, the following (1) to (1)
There are advantages as described in (5). (1) The sub-back wiring board 2 can be attached to the main back wiring board 1 to add or change a circuit simply by making a press-in contact using the contact pins 8 of the connector 3, thereby simplifying the assembly. (2) A highly accurate multilayer back wiring board can be easily realized at low cost. (3) Since only necessary parts can be multi-layered, it is economical. (4) For example, if only the power supply circuit is provided on the sub-back wiring board 2 side and only the signal circuit is provided on the main back wiring board 1 side, the power supply capacity can be secured, and the noise from the power supply can be reduced. The effect of not being transmitted to is obtained. (5) When the auxiliary back wiring board 2 is formed of a metal such as a copper plate, it can be used as a bus bar for large-capacity power supply.

3 and 4 show another embodiment of the back wiring board structure according to the present invention. FIG. 3 is a schematic perspective view of the back wiring board structure, and FIG. It is sectional drawing which shows a part typically. 3 and 4, the same reference numerals as those in FIGS. 1 and 2 denote the same components as those in FIGS. 1 and 2. 3 and 4, in this embodiment, two main back wiring boards 1 (A) and 1 (B) are connected to one.
This structure employs a structure in which two sub-back wiring boards 2 are connected, and the other structure is the same as the structure shown in FIGS. In the case of the structure according to the present embodiment, the main back wiring boards 1 (A) and 1 (B) may be housed in the same subrack or may be housed in another subrack. .

When the structure is configured as in this embodiment, in addition to the advantages described in the embodiment shown in FIGS. 1 and 2, the following effects (1) and (2) can be obtained. Can be (1) A plurality of main back wiring boards 1 (A), 1 (B), etc. can be connected without using cables with connectors. (2) For example, if the main back wiring board 1 (A) is separated by an analog circuit and the main back wiring board 1 (B) is separated by a type of signal such as a digital circuit, the back wiring board structure resistant to noise is relatively simple. Can be realized.

FIGS. 5 and 6 show still another embodiment of the back wiring board structure according to the present invention. FIG. 5 is a schematic perspective view of the back wiring board structure.
FIG. 6 is a sectional view schematically showing a main part of the back wiring board structure. In FIGS. 5 and 6, the same reference numerals as those in FIGS. 1 and 2 denote the same components as those in FIGS. 1 and 2. 5 and 6, this embodiment employs a laminated structure in which two sub back wiring boards 2 (A) and 2 (B) of different types are stacked on one main back wiring board 1 and connected. The other structure is the same as the structure shown in FIGS.
It should be noted that the number of the sub back wiring boards 2 to be laminated may be more than two as long as it is two or more.

When the structure is configured as in this embodiment, in addition to the advantages described in the embodiment shown in FIGS. 1 and 2, the following effects (1) and (2) can be obtained. Can be (1) A circuit can be added only to a necessary part. (2) Sub-back wiring board 2 (A), 2
If (B) is formed of a relatively thin printed wiring board and circuit components such as resistors are mounted, circuit components can be added to necessary parts.

[0018]

As described above, according to the present invention,
The auxiliary back wiring board can be attached to the main back wiring board simply by press-in contact using the contact pins of the connector. By adding this auxiliary back wiring board, it is possible to add and change circuits easily and at low cost. It can be expected to have an effect such as

[Brief description of the drawings]

FIG. 1 is a schematic perspective view of a back wiring board structure shown as an embodiment of the present invention.

FIG. 2 is a cross-sectional view schematically illustrating a back wiring board structure according to an embodiment of the present invention.

FIG. 3 is a schematic perspective view of a back wiring board structure shown as another embodiment of the present invention.

FIG. 4 is a cross-sectional view schematically showing a back wiring board structure according to another embodiment of the present invention.

FIG. 5 is a schematic perspective view of a back wiring board structure shown as another embodiment of the present invention.

FIG. 6 is a cross-sectional view schematically illustrating a back wiring board structure according to another embodiment of the present invention.

FIG. 7 is a schematic perspective view showing an example of a conventional back wiring board structure.

FIG. 8 is a cross-sectional view schematically showing one example of a conventional back wiring board structure.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Main back wiring board 2 Secondary back wiring board 3 Connector 4,5 Through hole 6 Printed wiring board 8 Contact pin

Claims (3)

(57) [Claims] 1. A back wiring board structure comprising a connector which is mounted by press-fitting a contact pin into a through hole, and wherein a printed wiring board housed in a subrack is mounted via said connector. A main back wiring board having a main back wiring board, and a sub back wiring board having a through hole corresponding to the through hole of the main back wiring board, and the main back wiring board and the sub back wire
A ring board is closely adhered and laminated, and the length of the contact pin is set to a length that can penetrate the through hole of the main back wiring board and press-fit into the through hole of the sub back wiring board. A back wiring board structure, characterized in that: 2. The apparatus according to claim 1, wherein the auxiliary back wiring board is formed of a board smaller than the main back wiring board, and is arranged at a necessary portion so that a circuit can be integrated at the arranged portion. Back wiring board structure. 3. The back wiring board structure according to claim 1, wherein the length of the contact pin is set to a length that can commonly penetrate the plurality of sub back wiring boards stacked at the same position. .