Surface mount advantages

The Quad Small Outline Package QSOP—also called a surface mount) is among the most commonly used types of chips today. Figure 1.7 shows an example of a QSOP package. This design has the advantage of being very compact. 

Piracci AF. Advantages of non-contact dispensing in SMT assembly processes. Chicago, IL Surface Mount Technology Assoc./ATE Sep. 2000. 

ACAs have been investigated as replacement for SnPb solder in surface mount (SM) attachment for fine pitch applications. The key attractive advantage is the cost effectiveness of using ACA to bond fine pitch SM components. A limitation of ACAs is the need to cure imder a contact pressin-e. The concept of using an ACA as a solder replacement on rigid chip carriers ntiUzing conventional SMT... 

Before the widespread use of solder mask, a primary method for protecting copper circuitry was to electroplate a coating of tin or tin-lead on the copper. After component insertion, the tin plating could be liquefied with oven or vapor-phase reflow to form solderjoints.The use of solder mask over bare copper to take advantage of surface mount, wave soldering, and mixed assembly restricted the use of tin plate finishing. For simple technology product, tin or tin-lead plate and reflow remains a viable fabrication and assembly method. 

An advantage of through-hole technology is reduced cost in some appUcations. That cost benefit may be realized by lower labor costs in some parts of the world that support hand assembly, which is relatively easy with the larger components and products, and lower board densities. Even when fully automated—either by wave soldering, selective soldering, or paste-in-hole/reflow—the capital equipment and manufacturing costs can stiU be lower than those required for surface-mount assembly. 

Owing to the widespread application of solar hot water systems, a great number of variations of fluid collectors have been developed and commercialized circulation. It is mostly the 1-2 m surface-mounted units that are available commercially these, joined in an appropriate number, form a full collector system. The advantage of commercially available collector surfaces is the quick and simple replacement of the elements and guaranteed thermal efficiency. A disadvantage is the usually high investment cost and the long payback time. For indirect solar dryers, lower cost is involved with panel-type collectors, if the costs... 

The development of surface-mounted technology (SMT) using surface-mounted devices (SMD) was a major development. SMD are active and passive electronics components without conventional connecting wires. SMD components can be placed on the solder side of the PCB and their metal caps soldered to the copper pads of the PCB. Both layers of the PCB can therefore be used as active areas. The SMT technique opened advantages and new applications through miniaturisation of components and increased reliability. 

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