Mechanical Properties and Interface Microstructure of SAC305 Solder Joints Made to an Ag-Pd-Pt Thick Film Metallization: Part 1—Processing Effects

The processibility was document for interconnections made between the 96.5Sn-3.0Ag-0.5Cu (wt.%, abbreviated SAC305) Pb-free solder and an Ag-Pd-Pt thick film conductor on an alumina substrate. The Sheppard’s hook pull test was used to assess the solder joint strength. Microanalysis techniques documented the corresponding microstructures. Excellent solderability was observed across the process parameters defined by the soldering temperatures of 240–290°C and soldering times of 15–120 s. Molten SAC305 solder dissolved the Ag-Pd-Pt thick film, leading to the precipitation of Ag (trace of Pd) and (Pd, Pt)xSny intermetallic compound (IMC) particles upon solidification. The mechanical strengths of the solder joints were excellent (10–15 N) and remained largely insensitive to the processing conditions. The failure mode was ductile fracture in the solder. These findings confirmed that the SAC305 solder/Ag-Pd-Pt thick film interconnection system had the necessary process window for use in high reliability, hybrid microcircuit (HMC) applications.

Design and Development of Detector Simulator for Total Ionized Dose and ground checkout system of radiation monitoring instrument

This Paper describes the simulator development for the Total Ionizing Dose (TID) measurement of radiation monitoring instrument. The TID Detector (UDOS001-micro dosimeter) is a compact hybrid microcircuit which directly measures Total Ionizing Dose absorbed by an internal silicon test mass. The developed detector simulator, simulates the equivalent Total Ionized Dose absorbed from the space radiation and Ground checkout simulator receive the data from Radiation monitoring Instrument through UART and process it for the functional verification of the Radiation monitoring Instrument, which is discussed in the paper.

Test Method of Current Leakage for Dielectric Paste

A test method of current leakage for dielectric paste was proposed by simulating the application processes of dielectric paste for manufacturing the dielectric layer in the multilayer thick film hybrid microcircuit. That is, by screen printing and sintering processes, the sliver conducting layer was fabricated on the surface of glass substrate, and then dielectric layer, finally the glass substrate sample with conducting layer and dielectric layer was dipped in 5 Wt% NaCl aqueous solution. The conductive line was soldered on the silver conducting layer to form the test circuit, and powered with 5 volts direct power, the current in the test circuit was taken as the current leakage of the dielectric paste. The method may be used to evaluate the current leakage of dielectric paste.