Abstract: A method for producing an electronic circuit assembly (e.g., a circuit board) from an etched tri-metal-layer structure which provides air bridge crossovers and specially designed bumps etched from a middle layer of the tri-metal-layer structure. The bumps are formed at particular circuit locations in order to provide interconnects for (1) heavy wirebonding, (2) fine wirebonding, or (3) direct chip attachment; or, to provide (4) lifters for assuring a minimum solder joint standoff height or (5) barriers for retarding solder joint crack propagation.

Abstract: A method for producing an electronic circuit assembly (e.g., a circuit board) from an etched tri-metal-layer structure which provides air bridge crossovers and specially designed bumps etched from a middle layer of the tri-metal-layer structure. The bumps are formed at particular circuit locations in order to provide interconnects for (1) heavy wirebonding, (2) fine wirebonding, or (3) direct chip attachment; or, to provide (4) lifters for assuring a minimum solder joint standoff height or (5) barriers for retarding solder joint crack propagation.

Abstract: An application program and computer system for determining the testing profile for accelerated laboratory random vibrational testing of a product, including the application program steps of (i) selecting the frequency range covered in the laboratory accelerated testing, (ii) developing a simplified composite Power Spectral Density function PSD.sub.j (f) representative of the PSD for random vibration loadings in expected field vibration levels, (iii) developing the shape of PSD.sub.T for producing on the product the test acceleration forces corresponding to the PSD.sub.j function, (iv) calculating the stress response curve H(f) for the product representative of the transmissibility function from the input acceleration forces to the local vibration stress forces, (v) selecting the test duration, and then calculating the amplification factor from the relationship ##EQU1## (vi) recalculating the accelerated PSD profile, PSD.sub.

Abstract: A method for joining a component to a substrate applies a base solder portion to the substrate and provides a standoff solder portion in the base solder portion. The standoff solder portion has a higher melting temperature than the base solder portion and a height which substantially corresponds to a desired standoff height between the component and the substrate. The component is positioned on the standoff solder portion and the base solder portion is melted under reflow conditions to form a solder joint between the component and the substrate. This joint substantially encapsulates the standoff solder portion, wherein the reflow conditions create a dendritic structure between the base solder portion and the standoff solder portion.

Abstract: An application program and computer system for determining the testing profile for accelerated laboratory sinusoidal vibrational testing of a product, includes the application program steps of (i) selecting the type and rate for the frequency sweep, (ii) developing a simplified composite Power Spectral Density function PSD.sub.j representing expected field vibration levels, (iii) developing the acceleration force function G.sub.T (f) corresponding to the PSD function, (iv) determining the stress response curve H(f) for the product, (v) selecting the number of frequency sweeps N.sub.W based on the testing equipment, the testing time available, and the range of acceleration forces required for implementing G.sub.T (f) from the relationship ##EQU1## where K is a constant, (vi) recalculating the acceleration forces G.sub.u, and then (vii) testing the product using the selected variables to validate the required performance lifetime for the product when no test failures are observed over all of the N.sub.

Abstract: A method for determining the testing profile for accelerated laboratory random vibrational testing of a product, including the steps of (i) selecting the frequency range covered in the laboratory accelerated testing, (ii) developing a simplified composite Power Spectral Density function PSD.sub.j (f) representative of the PSD for random vibration loadings in expected field vibration levels, (iii) developing the shape of PSD.sub.T for producing on the product the test acceleration forces corresponding to the PSD.sub.j function, (iv) calculating the stress response curve H(f) for the product representative of the transmissibility function from the input acceleration forces to the local vibration stress forces, (v) selecting the test duration, and then calculating the amplification factor from the relationship ##EQU1## (vi) recalculating the accelerated PSD profile, PSD.sub.

Abstract: A method for determining a sample size W required for accelerated testing of a product includes the steps of selecting a Reliability Goal R as appropriate for the product, selecting a Confidence Level CL appropriate for the accuracy required from the results of the accelerated testing, selecting the number of testing cycles N.sub.t defining the accelerated testing period, calculating the Sample Size W for the accelerated testing as ##EQU1## and then testing the W product samples for the N.sub.t testing cycles to validate the required Reliability when no test failures are observed over the N.sub.t testing cycles. A method for determining the Number of Cycles N.sub.t required for accelerated testing of a product having a service lifetime is also described. In either of the above methods, if any failures are observed in the N.sub.t testing cycles/time, then the number of testing cycles/time may be extended to at least 2 N.sub.

Abstract: A method for determining a sample size W required for accelerated testing of a product includes the steps of selecting a Reliability Goal R as appropriate for the product, selecting a Confidence Level CL appropriate for the accuracy required from the results of the accelerated testing, selecting the number of testing cycles N.sub.t defining the accelerated testing period, calculating the Sample Size W for the accelerated testing as ##EQU1## and then testing the W product samples for the N.sub.t testing cycles to validate the required Reliability when no test failures are observed over the N.sub.t testing cycles. A method for determining the Number of Cycles N.sub.t required for accelerated testing of a product having a service lifetime is also described. In either of the above methods, if any failures are observed in the N.sub.t testing cycles/time, then the number of testing cycles/time may be extended to at least 2 N.sub.