Investigation on Functional and Reliability Properties of IR Heaters for Soldering Processes in Connection with Spectral Characteristics of Radiation Control

In the article an approach for estimation of the longevity and reliability of low inert heating elements for the middle IR spectral region is proposed. Investigations deal with application of low inert heaters at soldering processes of SMDs. They possess a lot of advantages with respect to conventional heaters for the same purpose, especially to control in situ the spectral characteristics of radiation according to absorption properties of the heated objects. To ensure proper power radiation in the spectral region of lambda=2-3 mum from the same heaters their surface temperature should be raised at least to 1000 K while their operation temperature isn´t usually more than 720 K. The ageing law based on design and technological peculiarities of used low inert heating elements is proposed. Applying statistical approach operating durability of the heaters is evaluated. It allows estimation of the parameters of accelerated reliability tests as well as the influence of different operation factors on the low inert IR heaters life. The possibility of realization of versatile IR heating regimes which differ in power and spectral distribution of radiation is evaluated.