Strength and Lifetime Analysis of SMT Solder （强度和寿命分析SMT焊接）.pdfVIP

Proceedings, SMI ‘97, San Jose, CA, September 7-11, Best Paper award, second prize Strength and Lifetime Analysis of SMT Solder Joints: An Exemplary Study of the MiniMELF Component J. Jendrny, W.H. Müller, Universität-Gesamthochschule Paderborn, and H.-J. Albrecht, Siemens AG, ZT ME 7, Berlin ABSTRACT gested and will be demonstrated for a real SMT-structure, The reliability and lifetime of SMT solder joints obtained the “MiniMelf” (metal-elektrode-facing) resistor: by reflow or wave soldering are investigated for the case of an electronic miniature resistor. Life-limiting issues The first step consists of a non-linear three-dimensional addressed in this paper include irreversible deformation finite element (FE) analysis of the thermally loaded struc- due to plasticity and creep, faulty positioning of the mi- ture. In the present case the thermal loading follows the cro-electronic component, and a discussion of the influ- requirements of military specification Mil-Std-883, ence of processing techniques (reflow vs. wave solder- method 1011, condition B [1] and consists of thermal ing). The study decisively relies on a three-dimensional, cycling between +125°C and -55°C, as shown in Figure 1. non-linear finite element (FE) analysis, the results of which are used as input to various damage models. The A detailed discretization of a wave as well as a reflow analytical prediction of lifetime is finally compared with soldered structure is performed in a semi-automated fash- experiments in order to prepare its transfer to real