The application of through-transmission acoustic inspection to packaging strategies such as ball grid array (BGA) circumvents many of the problems encountered applying conventional pulse-echo inspection to BGAs. A unique feature of pulse-echo acoustic inspection is detection of delaminations in internal interfaces, which is based on the inversion of the pressure pulse (1800 phase shift) at the delamination. This article describes the advantages and applications of pulse-echo acoustic inspection and presents an experimental comparison of pulse-echo and through-transmission methods. It discusses the difficulties that BGA packages present to pulse-echo inspection, such as the complexity of the pulse overlap problem in pulse-echo inspection of the laminate, the problem of multiple echo signals overlapping in time is the possibility of interference effects, and that phase inversion cannot always be relied upon to assist in delamination detection. Practical considerations for through-transmission inspection are also covered.

A method of measuring moisture in the ceramic Package (pKG) without the destruction of the samples was developed (We define KNH method: kinahi method). The moisture oondition in the cavity can be oonfirmed by the temperature dependence of the leakage current between adjaoont terminals (At least one of measured terminals is non-oonnect). This method is performed by measuring the leakage current between non-oonnect terminals at various temperatures. The temperature is raised from room temperature. In the caseof the standard sample which has no moisture in the cavity, the leakage current increases as the temperature is raised. However, a sample which has a large amount of moisture in the cavity has a leakage current that decreases with increasing temperature and increases after this cycle. When the temperature is raised, the leakage current decreases because of a decrease in oondensed moisture. After the temperature without oondensing, the leakage current increases as same as standard sample. When this KNH method is used for the product which has no non-oonnect terminals, the leakage current can be measured by using the signal terminals at 0.2V which is the voltage under Vt of protection diode. This KNH method is very useful for oonfirmation of the slight leakage current of fine ceramic PKG and for the amount of moisture in the cavity

Laser microchemical (LMC) technology has become an important element of the FIA and debug tool set by supplying key steps not well addressed by previous tools. In this paper we report the optimization of the LMC technology to solve key issues for flip chip FIA. Specific processes have been developed for localized thinning of flip chips, in order to enable access of conventional FIA tools. Additional applications include dramatic enhancement of focused ion beam (FIB) rework and 3-D micromachining for prototyping, in-situ trimming, and mastering of microelectromechanical systems (MEMS). Laser etching of silicon is with a high pressure chlorine assist and is l000X the rate of the fastest focused ion beam methods. In contrast to grinding methods, the process introduces no process stress or contamination and retains an average surface roughness of several hundred angstroms. Micronthickness metal lines are laid down in a one-step vapor phase deposition at 200 μm/s writing speed. Rapid deposition combined with the superior quality of the laser interconnect, translates into writing with a conductance per unit writing time of 1000 to 10,000 times the rate of a focused ion beam.

Single Contact Electron Beam Induced Current (SCEBIC) microscopy, a new junction imaging technique suitable for visualization of unconnected pn junctions in integrated circuits is presented. By using the substrate contact alone of a die, the SCEBIC approach eliminates the need to connect a junction to the imaging electronics as is done in the conventional Electron Beam Induced Current (EBIC) technique. The principles of SCEBIC are discussed and experimental data which validate the SCEBIC approach for imaging of pn junctions is presented. Examples of SCEBIC images are presented and applications of SCEBIC microscopy in IC failure analysis are discussed.