PoP technology makes wearables viable market for board makers.

Embedded Computing Boards is much more than industrial PCs. In fact there are unique and differentiating technologies such as PoP, which stands for Package on Package technology that can be offered by only a few embedded board companies.  One such company that possesses this capability is Mistral Solutions.  Recently I had the opportunity to talk to their Associate Vice-President of Hardware, S. Vijay Bharat, who was a wealth of information on PoP technology.  Here is a summary of what I learned.

Over the past decade the embedded world has undergone tremendous change. With the advent of mobile phones, and other smart lifestyle gadget like wearables, health wellness devices, users are demanding smaller and thinner gadgets. This is where PoP can provide a competitive advantage.

Package on package (PoP)

PoP is a stacked packaging method to have two ball grid array (BGA) packages mounted one above the other with a standard interface to route signals between them. The most commonly components used for stacking are the processor and memory.

Stacking memory is one way to achieve the dual goals for enhanced functionality and greater packaging density of a product. It is fast becoming a promising solution in the wearable market, offering high integration that leads to product miniaturization.


Advantages of PoP.

  • Reduction in the PCB size by stacking packages
  • Reduction in the no. of layers of the PCB as the connection lines between the processor and the memory are minimized
  • Improves signal integrity on the board by minimizing trace length between different interoperating parts, such as controller and memory. The direct interconnections between the circuit yields reduced propagation delay, noise and cross-talk.
  • Easier memory scalability on the hardware. Most of the memory modules for PoP design come in multi-chip packages (eg: Flash + DDR). Hence, both the Flash and DDR memory can be upgraded by replacing the single PoP memory package. And finally, there is the
  • Reduction in BoM cost achieve as a result of elimination of termination discretes on the PCB.

Applications areas for PoP

Wearable applications can benefit from the combination of this stacked package, offering small footprint and minimal PCB space. Other portable electronic products such as

  • mobile phones (baseband or applications processor plus combo memory)
  • digital cameras (image processor plus memory),
  • PDAs, portable media players (audio/graphics processor plus memory)

[Image source: http://corelis.com/]

The ARM advantage

PoP technology is most popularly being used with ARM chipsets. Texas Instruments and Freescale two of the silicon vendors that adopted this technology. ARM chipsets are well suited because of low power and are small footprint. According to S. Vijay Bharat “The low power ARM devices ensures less thermal radiation to the memory; when it is placed over the processor in the PoP technology. Other competing compute architectures  are high in power and high in thermal radiation which increase the possibility of the memory to stall during operation.”

It is interesting to see that companies like Mistral Solutions are championing technology that will help enable the fast grow wearables market providing solutions that are both high performance, highly integrated and miniaturized!  Wearable is all about being small and lightweight, creating complex embedded boards in uniquely small form factors is a unique and differentiating technology.  Mistral Solutions is an  example of an ARM ecosystem partner creating value by focusing on differentiating tech.

  • Yes, I like your Article, thanks for sharing!

    As we offer the same technology at TechNexion and had this issue once recently at a special project (Multimedia Application outdoor, surrounding temp up to 60 degrees) I thought it's wort mentioning to pay attention to it

    Looking for your next Article.

  • Thank you for the comment.  Mistral Solutions certainly has a unique technology that I thought others should know about.  You are right the applications always has an influence on the requirements such as thermal. 

  • Good Article. PoP is indeed a great technology.

    However it always depends on the application, like you wrote 'thermal radiation to the memory' or better ‘trough’, this can be really a issue sometimes, even with 'only' a 4 core ARM Processor. Under normal usage this is ok, but if you use the GPU and all 4 Cores at maximum you limit your maximum upper operation temperature.