Introduction to POP packaging

POP

What is POP, it may be difficult to understand what this abbreviation means if you have not paid attention to it or have not been involved. POP is Package on Package, stacked packaging technology.

reason

Small electronic devices have some memory, processor, power supply, etc. on the printed circuit board (PCB). A common design is that these devices are individually packaged and arranged side-by-side. In order to add more, latest, and feature-rich applications, which require more and more memories, there is an urgent need to stack memory devices in the same package size and form factor.

Obviously, one of the advantages of this vertical combination of different packages is saving board space. POPs are an excellent packaging solution for applications that require more functionality in less space, such as digital cameras, PDAs, MP3 players, and mobile gaming devices.

POP assemblies typically consist of only two packages, such as a memory device mounted on top of a logic device.

Most companies that are developing POP assembly capabilities are leveraging well-established assembly processes and infrastructure (such as those used for CSP, BGA, and flip-chip), so little development is required for top-level packaging
.

The bottom or base package can also be die stacked to allow the incorporation of analog functions or flash memory into the logic die.

POP principle

A simple understanding is to stack two chips together. Of course, it is not a simple stack. We must consider the effects of stress, heat dissipation, and signal integrity.

Advantage

According to Amkor's website, POP is an enabling technology with the following advantages:

1. It provides an efficient logic and memory 3-D integration platform for OEMs and EMS;

2) Simplify the business logistics of stacking;

3. Allows integration control at the system level, facilitating stack composition optimization;

4) Eliminate margin stacking and expand technology reuse;

5. It helps to mitigate the impact of high costs usually associated with multimedia processing; 6) enables mass customization of the system to meet various usage needs.

detailed design

This part seems to be handled by the packaging factory. We just use it like a normal chip, so we don’t need to pay too much attention.

reference

https://www.ti.com/lit/an/sprabb3/sprabb3.pdf

https://www.dfrsolutions.com/hubfs/Resources/sherlock/Challenges-with-Package-on-Package-PoP-Part-1-Manufacturability.pdf