chip scale package (chip design) (CSP)
In many applications, the package size of the chips still plays an essential role, for example in hearing acoustics and telemedicine where complete video recording and transmission devices are hidden in a capsule that is insignificantly larger than a medicine capsule. For this reason, chip packages are getting smaller and smaller thanks to modern chip assembly techniques. The BGA package illustrates this trend, which continues in the chip scale package( CSP).
The CSP package takes its name from the chip size and is defined such that the chip must occupy 80% or more of the package area. The package thus has a size that is only slightly larger than the dice. The form factor is about 1.2. An even more favorable form factor between package size and chip size is offered by the Wafer Level Package(WLP).
The CSP package can have 8 to 64 connections. The sizes of the very compact packages range from 2 mm x 2 mm over 4 mm x 4 mm up to 9 mm x 9 mm for a CSP package with 64 connections.
In the CSP package, as in the BCC package, which it is very similar to, there are no connections outside the plastic body. Other chip-scale packages have evolved from the basic package; for example, the LFCSP (leadframe), WCSP ( wafer) and WLCSP (wafer- level), the MLP package ( micro leadframe package) and the leadless plastic chip carrier( LPCC).
The CSP package is used for memory and microprocessors, controllers, RF circuits, flash memory, Static RAMs( SRAM), Dynamic RAMs ( DRAM), ASICs (Application Specific Integrated Circuit), DigitalSignal Processor ( DSP) and Programmable Logic Devices ( PLD) because of its small size and light weight.