The task of calculating the resonant frequencies is relevant in the design of printed circuit assemblies structures of onboard electronic devices. Analysis of the amplitude-frequency characteristics based on the estimated values of the resonant frequencies and their subsequent analysis is indicative of the technical condition of the object of study.All geometrical dimensions of the structural elements of the electronic device and the location of the electronic components on the printed circuit board have to meet the tolerances specified in the design documentation. It is impossible to maintain an exact technology during production, therefore all parameters may have tolerance limits.Any changes in the parameters of the printed circuit assembly within the tolerance leads to a variation of the resonant frequencies relative to the idealized value, therefore forming the tolerance intervals of the resonant frequencies.

The paper describes the methods for calculating the diversities of the printed circuit resonant frequencies: experimental, the worst case method, the method of moments and the Monte Carlo method. The analysis of the features of each method is made. It is proposed to use the Monte Carlo method, as having the greatest accuracy and ease of implementation, taking into account the computational capabilities of modern electronic computers.A block diagram of the Monte Carlo method application is proposed, the mathematical apparatus is presented. The process of integrating software systems for calculating the diversities of the resonant frequencies of a printed circuit assembly is described.