Through Hole Technologies

Imagers having detector arrays directly contacting the read-out chip are presented in this chapter. The imagers having electrical connections made by through hole technologies are presented in a separate section. 

Summary - Connections made by Through Hole Technologies... 

Through-hole technology The technology of using leaded components which require holes through the substrate for their mounting (insertion) and soldering. 

Plated-Through-Hole Technology. PTH technology is discussed in some detail in Sec. 5.7 however, some comments are appropriate here. 

Silver-Through-Hole Technology. STH boards are usually made of paper phenolic materials or composite epoxy paper and glass materials, such as CE-1 or CE-3. After doublesided copper-clad materials are etched to form conductor patterns on both sides of the panel, holes are formed by drUUng. Then the panel is screened with silver-filled conductive paste. Instead of silver, copper paste can also be used. 

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. 

Impact of Pb-Free Soldering on Through-Hole Technology... 

Until the early 1980s, PCB were manufactured using through-hole technology in which the components were placed on the components side of the PCB, wires inserted into holes, and soldered to copper pads on the opposite, solder side of the PCB. 

Through-Hole Technology. Mixed results with fatigue life, for CPGA-84 better than eutectic tin-lead for CDIP-20 worse than eutectic tin-lead. 

Through-Hole Technology. Most joints exhibit fillet lifting. 

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