Technical Library | 2022-04-29 00:49:12.0
Tools: soldering iron, soldering iron stand, wet sponge, tweezers, rosin, solder, absorbent cotton, 95% alcohol, chip resistors, capacitors, circuit boards, 220V power supply..... http://www.leadersmt.com/gen2/1028113523/?mod=file&col_key=download
Technical Library | 2008-02-26 15:02:19.0
More and more chip packages need multi-GHz RF structures to meet their performance targets. The ideal chip package needs to combine RF features with Digital features for these applications. They drive low-loss, controlled impedance transmission lines, flexibility in assigned signal and power layers, and clearances of various shapes in power layers. Building these features in a chip package is difficult without making the stack-up very thick or compromising the reliability of the product. In the present paper, we have designed and built a flip-chip package test vehicle (TV) to make new RF structures, using Z-axis interconnection (Zinterconnect) building blocks.
Technical Library | 2021-10-20 18:21:06.0
The solderability of the SAC305 alloy in contact with printed circuit boards (PCB) having different surface finishes was examined using the wetting balance method. The study was performed at a temperature of 260 _C on three types of PCBs covered with (1) hot air solder leveling (HASL LF), (2) electroless nickel immersion gold (ENIG), and (3) organic surface protectant (OSP), organic finish, all on Cu substrates and two types of fluxes (EF2202 and RF800). The results showed that the PCB substrate surface finish has a strong effect on the value of both the wetting time t0 and the contact angle h. The shortest wetting time was noted for the OSP finish (t0 = 0.6 s with EF2202 flux and t0 = 0.98 s with RF800 flux), while the ENIG finish showed the longest wetting time (t0 = 1.36 s with EF2202 flux and t0 = 1.55 s with RF800 flux). The h values calculated from the wetting balance tests were as follows: the lowest h of 45_ was formed on HASL LF (EF2202 flux), the highest h of 63_ was noted on the OSP finish, while on the ENIG finish, it was 58_ (EF2202 flux). After the solderability tests, the interface characterization of cross-sectional samples was performed by means of scanning electron microscopy coupled with energy dispersive spectroscopy.
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