Mobility is now becoming pervasive. As the global population strives to
achieve constant connectivity, the trend that began with cellular phones and
was quickly replicated across consumer electronics with e-readers and tablets
is now being seen as a requirement in many other segments of the market, from
industrial to medical.
This demand results in the requirement for ever smaller printed circuit boards
(PCBs) and one of the most effective ways to achieve this is to stack two
packages on top of each other, known as package on package (PoP.) The two main
benefits of PoP are board space savings and minimizing track length between
different interoperating parts, such as a CPU and memory. This yields better
electrical performance of devices, since shorter routing of interconnections
between circuits yields faster signal propagation and reduced noise and
crosstalk. Based on these advantages more and more companies are looking to
design utilizing PoP most commonly placing the CPU on the PCB and stacking the
memory package on top.
The i.MX 6Dual/6Quad processors feature advanced
implementation of the quad ARM® Cortex®-A9 core, which operates at
speeds up to 1 .2 GHz. They include 2D and 3D graphics processors, 3D 1080p
video processing, and integrated power management. Since the launch of the
i.MX 6 series, customers have based designs ranging from automotive
infotainment systems to industrial, consumer and medical devices on these
processors. Both parts are currently available in a 21mm x21 mm 0.8 mm pitch
FCPBGA package, however we have increasingly been asked by customers to enable
smaller designs with these processors. Based on this customer demand, we will
be making i.MX 6Dual/6Quad processors available in a smaller 12 mm x 12 mm,
0.4 mm pitch, FCPBGA, PoP; with the upper package being a 4Gb mobile LP-DDR2
memory package from Micron. Both the top and bottom of the package meet JEDEC
standard design guideline ensuring easy of design and layout for customers.
The i.MX6 PoP will also be part of NXP’s longevity program so
enabling customers to utilize PoP for projects with long life cycles.
PoP, similar to any technology, has advantages but can also present design
challenges. Two challenges that may occur with any PoP are soldering, between
the packages and thermal dissipation. Both of these challenges can be overcome
if the two packages are designed and tested in a stacked PoP implementation.
We know that reliable PoP development requires close collaboration with the
memory vendor. This is why we choose to partner with Micron for our i.MX PoP
offering. Together, we can carefully engineer the packages and review the
thermal profiles to ensure maximum compatibility. Micron has published a POP
User Guide (CSN 34) that provides a wealth of technical information.
Micron is a major player with LPDRAM and PoP packages in the mobile/wireless
space, and now a market leader in supporting LPDDR to the non-wireless market
space. They worked closely with us in developing an automotive
temp grade 216b 8Gb (dual-die package) x64 LPDDR2 PoP package for use on the
i.MX6 Dual and Quad applications processors. This PoP device provides
simpler routing to a system and allows for board space savings to
customers. The LPDDR2 has been tested to be guaranteed to function up to
max temp of 105C temp (Normally max temp 85C.) The memory package also
includes on-die temperature sensors that can be used by software to throttle
the application processor down if the temperate gets too hot and increase the
refresh rate of the DRAM.
Working with Micron has enabled us to offer customers a reliable, longterm PoP
solution. However, we realize that many customers looking to capitalize of the
advantages of PoP have little experience with the technology. To provide not
only an evaluation board, but also design services and expertise in PoP
designs, we have worked with two partners that have extensive experience with
PoP designs across many industries, TechNexion and Mistral Solutions.
Mistral Solutions has recently launched the VISE board, that runs on the 800
MHz quad/dual core i.MX6 PoP . The VISE board is based on a dual board
architecture, consisting of a core module and a carrier module comprising
display, audio, gigabit Ethernet and other peripheral Interfaces. The VISE
Board is an ideal platform to kick-start design and development of devices
from wearables to security cameras. The VISE board is available via Arrow Technologies for more information on Mistral and the VISE board go to:
The Pico -6QPoP board from TechNexion is a small form factor (35 mm x 40 mm)
system-on-module that connects to a breakout board that contains sensors and
additional interfaces that enables easy access to peripherals. The Pico
board will be available in Q2 2015 from TechNexion and through major
Both boards will support both Yocto Linux and Android Kitkat ensuring both
customer choice and fast time to market for software as well as hardware
If you’re looking to design a product where small size is a premium,
take a look at our PoP solution that is coming soon, it might well be the
package you are looking for.
Robert Thompson is business development manager for NXP’s