Conventionally, in order to design a multi-board made up of a plurality of substrates having electrical connection relationship by utilizing electrical design CAD (Computer Aided Design) which performs electrical design of a substrate or the like, for example, it has been necessary to create connection information for connecting each substrate after each substrate was separately designed.
Specifically, in the case where a substrate A and a substrate B being constituent elements of the multi-board are connected by a connector, design of the substrate A, design of the substrate B and design of inter-substrate connection (i.e., design of a connected state of the substrates A, B by connectors) were performed separately (refer to FIG. 1(a)), and designed design information was saved in a magnetic disc to own each design information (refer to FIG. 1(b)).
It is to be noted that FIG. 1(a) shows a case where a component 1 is connected to a pin A3 of a connector 1 in the design of the substrate A, a component 2 is connected to a pin A3 of a connector 2 in the substrate B, a pin A1 of the connector 1 provided for the substrate A and a pin A1 of the connector 2 provided for the substrate B are connected, a pin A2 of the connector 1 and a pin A2 of the connector 2 are connected, and the pin A3 of the connector 1 and the pin A3 of the connector 2 are connected in the inter-substrate connection, in which the component 1 arranged for the substrate A is designed in a connected state with the component 2 arranged for the substrate B via the pin A3 of the connector 1 and the pin A3 of the connector 2.
In the design method of such a multi-board made up of a plurality of substrates, in the case where the arrangement position of the component 2 in the substrate B is changed from the state shown in FIG. 1(a) and a connection destination of the component 2 is changed to A1 of the connector 2 with the change for example (refer to FIG. 2), the connection destination of the component 1 provided for the substrate A had to be changed from the pin A3 of the connector 1 to the pin A1 in order to maintain connection relationship between the component 1 and the component 2.
However, in the design of the substrate A, substrate B and inter-substrate connection, a designer separately designed each item, so that a human-made error by the designer such as failing to changing the above-described connection destination of the component 1 or the like caused a case where the information of each design data did not cooperate with each other and connection relationship between the component 2 and the component 1 was not maintained, and connection relationship between the component 2 and the component 1 was not maintained.
Thus, connection relationship between the substrate A and the substrate B was not maintained, and a problem was pointed out that connection relationship between the substrate A and the substrate B being constituent elements of the multi-board could not be maintained.
Furthermore, in the case of performing each design for improving design efficiency by different designers, changed information had to be shared among a plurality of designers, and a problem was pointed out that the above-described human-made error became more prominent, and connection relationship between the substrate A and the substrate B being constituent elements of the multi-board could not be maintained.
It is to be noted that prior art that the present applicant knows at the point of filing a patent is not an invention known to the public through publication, so there is no prior art document information to be described in the present specification.