Electronic products are subject to miniaturising. Therefore, electronic components of these products need to be ever smaller and lighter. As a result, more and more integrated and high integrated circuits are required within even smaller packages. Connection pins in former dual-in-line (DIL) packages have been produced with 2,54 mm masks. Quad Flat Packages (QFP) were provided with 0,5 mm masks.
Reducing the sizes of the masks and increasing the number of connection pins generated the need for new designs, such as pin grid arrays (PGA) and ball grid arrays (BGA). The particulars of these designs are that they provide their connection pins throughout the whole array surface, rather than just on its periphery, as was the case with former designs.
To further reduce the size of the packages, it has been proposed to use flip chip technology and chip scale/size packages (CSP). Chip size packages are characterized in that the area of the package may not be larger than the die itself. For chip scale packages, the area of the package may not be larger than 1.2 times the size of the die.
CSPs being mounted on a carrier substrate and being connected to the substrate by bonding require complicated processing steps.
In particular ball grid arrays and CSPs are subject to significant failures in electronic components. These failures, which may be a consequence of a shock impacted from drop and fatigue from thermal and bending cycling, also apply to any other type of packages, interconnections and connection types, such as soldering and glueing. The packages fail mainly due to failure in the interconnection between the component and the printed wiring board, in particular in the solder joints or in the printed wiring board (PWB) build-up.
As failures within the electrical coupling elements are the reason for most of the malfunctions of electronic components and devices, there is a need to determine the components where the failure occurred. To allow easy, fast and inexpensive repair of electronic devices, it is required to find the components which are subject to broken coupling elements quickly. The lack of knowledge of broken components requires intensive laboratory analysis and long service time for end users, in case the equipment malfunctions. Current failure mode analysis is based on try and error methods. As the failure usually cannot be located exactly, often more components are replaced than necessary.