Method for outputting impact degree and information processing device

A method for outputting an impact degree, the method comprising:

• calculating, by a computer, a distortion amount that represents an amount of distortion generated in a via of a printed circuit board based on a following equation, Δε={(L×α×Δt×E)/(D×T)}×m×β×γ×η
• here, Δε is the distortion amount, L is a via length, α is a thermal expansion coefficient of a substrate of the printed circuit board, Δt is a temperature change of an environment in which the printed circuit board is used, E is the Young's modulus of the substrate of the printed circuit board, D is a via diameter, T is a plating thickness inside the via, m is a coefficient obtained by a stress calculation based on a theory of material dynamics and by a stress simulation, β is a first coefficient according to an arrangement of lands, γ is a second coefficient according to an arrangement density of vias on the printed circuit board, and η is a third coefficient according to a positional deviation between vias and lands;
• calculating a lifetime of the via based on a following equation, M=N/(n×365)
• here, M is the lifetime of the via, n is a number of temperature changes, and N is a number of cycles of the lifetime, which satisfies a following equation, Nx=C/Δε
• here, x is a fatigue ductility index of a material used for plating, C is a fatigue ductility coefficient of the material used for plating, and Δε is the distortion amount;
• changing, when the calculated lifetime is outside a first setting range, at least two design values of the via length, the thermal expansion coefficient, the Young's modulus, the via diameter, or the plating thickness within a second setting range corresponding to the at least two design values respectively;
• giving points of two perspectives affected by the change for each of the at least two changed design values;
• and
• outputting a graph that indicates an impact degree according to the points of the two perspectives for each combination of the at least two design values.

An information processing device comprising:

• a processor configured to:
• calculate a distortion amount that represents an amount of distortion generated in a via of a printed circuit board based on a following equation (1), Δε={(L×α×Δt×E)/(D×T)}×m×β×γ×η
• here, Δε is the distortion amount, L is a via length, α is a thermal expansion coefficient of a substrate of the printed circuit board, Δt is a temperature change of an environment in which the printed circuit board is used, E is the Young's modulus of the substrate of the printed circuit board, D is a via diameter, T is a plating thickness inside the via, m is a coefficient obtained by a stress calculation based on a theory of material dynamics and by a stress simulation, β is a first coefficient according to an arrangement of lands, γ is a second coefficient according to an arrangement density of vias on the printed circuit board, and η is a third coefficient according to a positional deviation between vias and lands;
• calculate a lifetime of the via based on a following equation, M=N/(n×365)
• here, M is the lifetime of the via, n is a number of temperature changes, and N is a number of cycles of the lifetime, which satisfies a following equation, Nx=C/Δε
• here, x is a fatigue ductility index of a material used for plating, C is a fatigue ductility coefficient of the material used for plating, and Δε is the distortion amount;
• change, when the calculated lifetime is outside a first setting range, at least two design values of the via length, the thermal expansion coefficient, the Young's modulus, the via diameter, or the plating thickness within a second setting range corresponding to the at least two design values respectively;
• give points of two perspectives affected by the change for each of the at least two changed design values;
• and
• output a graph that indicates an impact degree according to the points of the two perspectives for each combination of the at least two design values.