I.A. Lozovoy, A.V. Turetsky

In modern electronic equipment reliability of solder connection of the radio-electronic module (RM) is the defining factor influencing reliability of all device. Procedure of quality control of solder connections with the purpose of detection of superficial, internal and through defects is established to GOST 19249-73, 23479-79, 18442-80 and 24715-81. Besides, GOST 26126-84 establishes ultrasonic (nondestructive) methods of quality control of solder connections. Standards extend on the solder connections executed in the various ways of the soldering, (convectional, infra-red, laser and so forth). However the majority of the above-stated methods can be applied only in production, to quality control of a let-out product. For reduction of the subsequent completions of a design of RM it is expedient to carry out the accounting of strength characteristics of solder connections at a product design stage. At this stage various software packages of the mechanical engineering analysis, allowing to define the most loaded sites of designs are widely applied. For the solution of these tasks the Pro/ENGINEER system Pro/ENGINEER Mechanica module (at present CreoParametric) can be used. He allows to carry out research of thermomechanical characteristics of projected products and their optimization on the set parameters. However in it there is no possibility to model behavior of solder contact under loading. The matter is that durability of contact depends on many factors: a type of solder, a mode of the soldering, type of the case of a component and so forth, and natural tests of various cases are necessary for receiving the most plausible results and creation on their basis of a database of critical values at which electric connection is lost. Therefore expansion of possibilities of the specified module by creation of a specialized subsystem of finding of critical parameters of the solder connections, consisting of testing installation and the specialized software operating its work and allowing to process results is expedient. The testing installation working under control of the personal computer where for communication the widespread USB interface is used is for this purpose offered, and specialized power keys are applied to management of drives. After preparation of examinees of samples of electronic components there is their installation on the test printed-circuit board, carry out a series of tests according to the IEC-PAS 62137-3 standard, the obtained data are transferred in the personal computer and by means of statistical calculations average value of the minimum threshold of refusal of solder connection is defined. In such way it is possible to save up rather extensive information on durability of solder connections of different types of cases. These data can be used at RM design stage, after carrying out the engineering analysis in Pro/ENGINEER Mechanica system. Carrying out the specified tests on offered installation allows to define the limiting parameters defining reliability of solder connections of SMD that will help to define unequivocally need of further completion and testing of radio-electronic modules for mechanical characteristics.