This research investigates the microstructure and growth behavior of the intermetallic compound(IMC) of Sn-1.0Ag-0.5Cu,Sn-1.0Ag-0.5Cu-0.05Ni and Sn-1.0Ag-0.5Cu-0.05N-0.02B/Cu solder joint interface. The interfacial reactions between Cu and the solders at 250±1°C were examined. Experimental results indicated that the IMCs of the above alloy systems on the soldering interface were Cu6Sn5and (Cux, Ni1-x)6Sn5, respectively. The grain size of primary Sn decreased observably with the micro addition of B and a large number of fine reinforcement particles were found in the solder. With the aging time increasing, the (Cux, Ni1-x)6Sn5micrograph of the Sn-1.0Ag-0.5Cu-0.05N-0.02B solder joint interface was changed from sawtooth-like to shape-layer, but the thickness of IMCs increased unobservably.

No abstract

The paper uses D level,E level and the level of GPS control network establishment satellite space geodetic network in Laicheng industrial zone in Laiwu, through the baseline calculating, three-dimensional unconstrained adjustment and two-dimensional constraint adjustment to get the WGS-84 three dimensional coordinates and 1980 xi 'an horizontal coordinatesthe of control points; then using the fourth-order levelling connection survey all D-level, E-level control points and part GPS control points to build vertical control network, for the GPS control points of the remaining we utilize quadric function method using GPS elevation fitting given its elevation seek to obtain three-dimensional coordinates of all the basic control points.

The solder/substrate reactions, for Sn-1.0Ag-0.5Cu, Sn-1.0Ag-0.5Cu-0.05Ni and Sn-1.0Ag-0.5Cu-0.05Ni-0.02B, were evaluated in what concerns the melting temperature, microhardness, morphology of the solder and chemical composition of the interface layer. The phases formed at the interface between the Cu Substrate and a molten lead-free solder were studied with different stage times. The evaluation of their chemical compositions were performed by Scanning Electron Microscopy (SEM) and Energy Dispersive Spectrometer (EDS).

Taking use of VirtuoZos digital photogrametric workstations of Supresoft Inc., employing full digital aerophotogrammetric mapping method, according to existing aerial photographic image database, at the foundation of basic control survey, we carry out aerial photographic control survey, surveying and mapping with pile point method, digital aerotriangulation and full digital stereocompilation. When taking 1:1000 topographic map obtained by indoor edition to field work for compration, supplement and regulation, we mainly aim at the following purposes: determining the nature and quantity as well as filling vacancy for ground and land features obtained by indoor stereocompilation; positioning for habitation, wall and railing, incompletely surveyed, drop shadow-covered and trees-obstructed ground features, as well as newly-added planimetric features after aerial photogrammetry; especially measuring the solid width of a house to centimeter and making eaves correction after measuring the length of a house when needed; correcting the geomatric positioning relationand of ground features according to their solid shape and fairly drawing them in the map; afterwards, we carry out graphic edition again during indoor work. Only in this way can we guarantee the horizontal and vertical accuracy of large scale photogrammetric mapping.