F. G. Plotnikov, A. P. Chuyev
Today, the world electronics market fastest goes on mature stage. Connections are one of the major factors defining quality and reliability of radio-electronic equipment. Last years in addition to traditional solder connections have appeared alternative solderless ones deprived of solder application problems.
One of the most effective and perspective kinds of solderless connections are press-fit connections. Unlike solder connections the press-fit technology provides: gas-proof contact zone and high reliability; constant contact resistance; compensation of plated-through hole (PTH) sizes variations; elimination of high-temperature influences on printed-circuit boards (PCB); elimination of gas emissions and flux residues; elimination of PCB washing; elimination of short circuits probability; simplicity of process; press-fit connection maintainability and PCB safety; economic efficiency of process.
Thanks to the these advantages the press-fit technology has won popularity all over the world and now fast rates gets on the Russian market. The given circumstance speaks about necessity of more careful studying of all its posi-tive and negative sides.
The press-fit technology is used at PCB assemblies manufacturing during about 40 years. Within four decades this technology has developed in various areas, has earned an recognition and now it is considered perspective technology, thanks to the advantages specified above. The basic components of press-fit connections are pressed pin, PCB and PTH. The basic components of compliant pins are заходная zone and press-in zone. The pin press-in zone is a specially profiled part of pin that is used for creation of press-fit connection. The press-in zone plays important role in press-fitting. Today it is developed and applied many variants of profiles and designs of pin press-in zones. Various press-in zone designs provide various press-fitting parameters which are necessary for considering at use of pins from any manufacturer though as a whole all pins, regardless of press-in zone, should correspond to IEC 60352-5 requirements. The estimation of press-in zone characteristics is better to conduct on such parameters, as: behavior of introduction of pins in PTH; behavior of indenting the pins in PTH surface; Pb-free coatings; press-fit technology application; PTH deformation; gas-proof level of electric contact; compression level of pin press-in zone; retention force.
Carrying out of the constructive-technological analysis on the parameters specified above allows to estimate all pluses and minuses of press-in zone versions and to offer recommendations about their application.
The press-fit technology continues to develop both into miniaturization and new versions of press-in zones. These trends will require the carrying out of new actions for an estimation of corresponding constructive-technological pa-rameters of pins.