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SMD (non-electrolytic) capacitors, which are usually monolithic ceramic capacitors, exhibit the same body color on all four faces not covered by the end caps. SMD electrolytic capacitors, usually tantalum capacitors, and film capacitors are marked like resistors, with two significant figures and a multiplier in units of picofarads or pF, (10 ...
During automated SMT pick-and-place, this happens mostly if the mechanical pressure of the SMD placer nozzle is too low. If the MELF components are placed into the solder paste with enough pressure, then this problem can be minimized. Care must be taken with glass diodes which are less mechanically robust than resistors and other MELF components.
A grid array of solder balls on a printed circuit board after removal of an integrated circuit chip. Cross-cut section of BGA mounted circuit. A ball grid array (BGA) is a type of surface-mount packaging (a chip carrier) used for integrated circuits.
In flip chip systems the IC is connected by solder bumps to a substrate. In beam-lead technology, the metallized pads that would be used for wire bonding connections in a conventional chip are thickened and extended to allow external connections to the circuit.
Selective soldering machine. Selective soldering is the process of selectively soldering components to printed circuit boards and molded modules that could be damaged by the heat of a reflow oven or wave soldering in a traditional surface-mount technology (SMT) or through-hole technology assembly processes.
Dye-n-Pry is a useful failure analysis technique to detect cracking or open circuits in BGA solder joints. [2] This has some practical advantages over other destructive techniques, such as cross sectioning, as it can inspect a full ball grid array which may consist of hundreds of solder joints. Cross sectioning, on the other hand, may only be ...
Some key QFN design considerations are pad and stencil design. When it comes to bond pad design two approaches can be taken: solder mask defined (SMD) or non-solder mask defined (NSMD). A NSMD approach typically leads to more reliable joints, since the solder is able to bond to both the top and sides of the copper pad. [4]
It is a useful test for all pad geometries and is sensitive to board design and materials. The ball pull test is specifically design for BGA components and has a large sensitivity to the solder alloy and joint formation. The ball shear test is also specified for BGA components and involves shearing the solder balls of the BGA.