Analysis and Experimental Validation of Solder Joints of CCGA Packages

Continuous development in electronics industries results in the introduction of many complex electronics packages. Nowadays, digital and frequency modulation technology occupies a major part in commercial, telecommunication, space, and defence electronics applications. Space industries use high-reliable electronics packages like the Ceramic Column Grid Array package (CCGA) which is programmable as per application in satellite modules. These packages have more number of columns for electronics as well as for mechanical strength. As the number of columns increases, mechanical strength increases, but same time screening of columns that are very closely constructed is very difficult. When these packages undergo screening tests like thermal cycling, there may be chances of solder cracks and bending of columns due to temperature variation. Thereafter, the high-level vibration test makes the solder cracks grow faster and bent columns to fail. These grid array packages shall be integrated onto PCB through reflow technology; reflow creates the solder fillets at the bottom portion of columns which mounts upon PCB. During these reflow processes, in any chance the solder fillet is not properly formed, and vibration test followed by thermal cycling may lead to damage of columns in-turn whole package. As the cost of one package itself is very high, damage to multiple packages may result in huge losses to industries. In this paper, two numbers of 1752 columns CCGA (VERTEX 5 CN1752 CCGA) packages are considered which are mounted on 2.6-mm thick, 12-layer polymide PCB. The board along with CCGA packages is placed inside an aluminium housing, and this assembly is considered to perform dynamic analysis like eigen value, sine response and random response analysis and is subjected to vibration tests to study the solder joint behaviour of CCGA columns; observations are discussed in detail.