Drawing file download : Samsung Semiconductor PDF

Mobile DRAM, or Low Power DDR (LPDDR/LPDDR2) RAM, is a version of the standard DRAM memory designed specifically for use in handheld, battery-powered computing and communication devices, such as mobile phones and PDAs. This document describes the most common packaging techniques for mobile DRAM, where the key features are having the smallest form factors and lowest power consumption.

Packaging Mobile Memory Devices

Mobile DRAM devices most commonly use FBGA (Fine-pitch Ball Grid Array) packages, which have several advantages, such as a thin and light structure, low profile (height), configurable ball pitch, and suitability for production of all types of devices on the mobile platform, such as processors, memory, and RF transceivers.

Because of extreme space constraints in the latest mobile devices, mobile DRAM is most commonly packaged using the PoP (package on package) technology, allowing board space to be used more efficiently. Furthermore, the PoP package also lends itself to easy installation on an SoC (system on a chip) package, forming a MCP (multi chip package) solution containing both the processor and memory on top of one another.

Figure 1 illustrates a cross-sectional view of a typical mobile DRAM encapsulated in an FBGA package.

Housed in either a square or rectangular body, FBGA packages for mobile DRAM are a type of CSP (chip scale package), which means that the size of the package is almost the same as the size of the chip inside the package.
FBGA packages also possess another important advantage: a significantly low mass, resulting in a low weight for the package. For FBGA packages, the ball pitch is also easily configurable from values as low as 0.40 mm to as high as 1.00 mm. Advanced processing and fabrication technologies available today enable a single FBGA package to have anywhere between 8, to more than 600 balls.

Samsung Semiconductor Package Information

Figure 2 illustrates an LPDDR2 mobile DRAM memory in an FBGA package.

Samsung's FBGA packaging uses the industry's best PCB substrates to achieve the chip scale packaging levels needed for small form factor mobile DRAM devices. The reduced outline and thickness offered by the package, coupled with its high density make it an ideal option for portable, high performance applications. FBGA packages offer the additional flexibility of letting the designer select the ball pitch, so that more I/O lines can be accommodated within the same form factor device.

Key Features and Benefits of Samsung's Packaging Techniques

Samsung has the industry's most advanced processing and packaging techniques for mobile DRAM. Some of the significant features of these techniques are listed below:

Application Areas for Samsung Mobile Memory Packages

Samsung's packaging techniques for mobile DRAM are the industry-standards and benchmarks for packaging mobile memory devices. Memory packaged using Samsung's advanced processing techniques are deployed across a wide spectrum of applications, some of which are listed below: