- MOBILE MEMORY
- APPLICATION PROCESSOR
- IMAGING SOLUTIONS
- DISPLAY DRIVER IC
- SECURITY SOLUTIONS
- VARIOUS PACKAGES
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.
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:
- Available in both discrete and PoP type packages:
- Samsung mobile DRAM packaging techniques encompass the best quality packaging in both the discrete and PoP types. The advantage of a discrete package is a very low profile for the package, whereas the advantage of a PoP package is a higher level of integration, higher memory density, and an efficient utilization of the available board area.
- Ultra-low form factors:
- Samsung mobile DRAM packages have very small form factors, enabling their deployment even in the most advanced and compact devices where board space is extremely limited. Available packages range in size from as small as 8.0 mm x 9.0 mm, to about 16 mm x 16 mm, providing efficient utilization of board space. Moreover, package profiles range from 0.8 mm, to about 1.4 mm, with significantly low masses, helping keep the weight of the end application as low as possible.
- Wide ball counts with configurable ball pitches:
- Samsung mobile DRAM packages offer easily configurable ball pitches, from 0.40 mm, to 1.00 mm. Because of this ease of configurability, ball counts can be taken to values as high as 600 in a single FBGA package.
- High memory density:
- Samsung's advanced processing techniques ensure that a PoP design for a mobile DRAM module can accommodate up to 4 dies per stack, significantly increasing the density for the chip.
- Stable and dependable thermal performance:
- Mobile DRAM memory packaged using Samsung's advanced packaging techniques demonstrate excellent thermal stability, preventing conditions such as thermal runaways, and are capable of handling powers up to 2 W.
- Superior electrical performance:
- Samsung's advanced routing techniques for mobile DRAM ensure that power and ground nets are routed over as short a distance as possible. This makes it easy for packages to deploy multiple layers for power and ground management. Additionally, it also makes it easy to deploy differential signaling using separate layers, with controlled characteristic impedances, making it possible to simplify connectivity for interfaces such as USB and SATA which use differential signaling.
- Available in lead- and halogen-free variants:
- Samsung's mobile DRAM packaging techniques use the latest, lead- and halogen-free manufacturing processes, making the material for the devices environmentally-friendly, and easier to recycle and reuse.
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:
- Mobile communication devices:
- Because of their critical space, weight, and power conservation requirements, mobile handsets are the principal beneficiaries of Samsung's advanced mobile DRAM packaging solutions.
- Handheld computing devices, such as tablet computers, and PDAs:
- Battery-powered, handheld computing devices that need sufficient performance from the memory subsystem at reduced power consumption levels, also stand to gain from Samsung's packaging solutions for mobile DRAM.
- Digital still/video cameras:
- Imaging devices, such as digital still/video cameras also require a high performance memory subsystem. Samsung's advanced manufacturing and processing techniques provide both performance as well as low power consumption, offering extended durations of usage for these devices.
- Consumer products:
- Consumer electronic products, such as digital TVs, Blu-ray players, and automobile navigation systems can greatly benefit from Samsung's highly advanced packaging solutions for mobile DRAM, which provides the highest memory densities and ball counts within the smallest package sizes.
- Analog, digital, and mixed-signal processors and chipsets:
- Mobile DRAM packaging technology from Samsung is deployed extensively in analog, digital, and mixed-signal processors, such as front-end RF chipsets for wireless transceivers, programmable logic devices (FPGAs and CPLDs), application processors, and other devices requiring high densities of memory on the chip.