March 20, 2025
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Early flip phones, while simple in function and only capable of making calls, represented a significant technological breakthrough at the time. Today, the expectation for technological advancements has not diminished; instead, it has grown stronger—consumers demand mobile phones with more powerful features, higher-resolution screens, longer battery life, faster processing speeds, and, most importantly, smaller form factors.
This demand extends beyond smartphones. Consumers expect continuous improvements in both functionality and size for various electronic devices, including earbuds, smartwatches, and household appliances such as hair dryers. If a new product does not offer improvements in cost, size, or functionality, most consumers are unlikely to upgrade.
The trend of miniaturization and enhanced functionality also influences embedded system designers, who strive to improve system capabilities while reducing the overall size and cost of their designs.
To support embedded system designers, semiconductor manufacturers, including Texas Instruments (TI), are developing microcontrollers (MCUs) and embedded processors with enhanced functionality in smaller packages. These components use optimized packaging to reduce the space occupied on printed circuit boards (PCBs), allowing room for additional components and larger batteries, thereby extending battery life. Internally, these devices are evolving by integrating a wide range of analog components to expand functionality while reducing the need for discrete components.
This article explores how packaging and analog integration help reduce the size of embedded processors while maintaining their functionality and discusses the impact of optimized packaging on the manufacturing process.
Packaging innovation is one of the few semiconductor advancements visible to the naked eye. To reduce package size, semiconductor manufacturers have moved away from traditional leaded packaging to advanced packaging options, eliminating unnecessary plastic casings and leads. These advanced packaging techniques directly correlate package size with the die size, minimizing the space required for achieving the desired functionality.
TI offers several compact packaging options in its embedded product lineup:
QFN packages eliminate traditional leads, replacing them with flat contacts around the plastic casing edges and an exposed thermal pad at the bottom for improved heat dissipation. Figure 1 shows the package diagram of the MSPM0C1104, a 20-pin microcontroller with a package size of only 9mm².
Figure 1: Drawing of MSPM0C1104 in 20-pin 0.8mm QFN package
These packages are even smaller than other packaging types. The solder ball array connects directly to the silicon die, making the package size equal to the die size (see Figure 2). This approach integrates eight solder balls within a 1.38mm² area, achieving higher functional density per square millimeter. Additionally, the MSPM0C1104 employs a WCSP package that is 38% smaller than similar devices, making it the world’s smallest MCU.
Figure 2: MSPM0C1104 8-ball WCSP package drawing (nominal value 1.50 x 0.86mm, thickness 0.35mm)
Another way to address limited PCB space is by optimizing functional integration within the device. Each discrete component requires its own plastic casing, leads, and PCB layout space, which collectively consume more board area than a single-chip solution with integrated functionality.
Integrated MCUs and processors that incorporate both analog and digital peripherals play a crucial role in miniaturization. Take a pulse oximeter as an example. Instead of using discrete components, integrating an analog-to-digital converter (ADC), comparator, and voltage reference into the MCU reduces the number of required components, thereby shrinking PCB size, as illustrated in Figures 3 and 4.
Figure 3: Design of a pulsatile oximeter with discrete analog elements
Figure 4: Pulsating oximeter design with integrated components
However, deciding which functions to integrate into an MCU involves trade-offs. While integration reduces component count, unnecessary functions can increase the chip size and cost.
This is why functional optimization is critical. Every added peripheral impacts the die size and overall cost. Unused functions can waste space and money, decreasing efficiency in space-constrained designs. Understanding real market needs allows the development of cost- and size-optimized embedded solutions. For instance, the MSPM0C1104 WCSP, with its eight solder balls, is not only compact but also highly functional. It features a 1.38mm² package with 16KB of flash memory, a three-channel 12-bit ADC, and three timers. By maximizing functional density per square millimeter, engineers can significantly improve space utilization in their designs.
Figure 5: Size comparison between the MSPM0C1104 and the wireless headset
As semiconductor devices shrink, design and manufacturing methods must evolve. While reducing electrical component sizes helps minimize PCB dimensions, layout, handling, and production processes must also be considered.
When designing with chip-scale packaging, two common types of PCB pad patterns are beneficial: Solder Mask Defined (SMD) and Non-Solder Mask Defined (NSMD) (see Figure 6).
Figure 6: NSMD and SMD PCB pad pattern
SMD pads have larger copper areas overlapping with the substrate.
NSMD pads have smaller, more precise copper pads, providing better uniform coverage, improved routing capabilities, and lower stress.
Component placement and handling also present challenges. Semiconductor and product manufacturers must carefully handle WCSP and BGA packages to minimize the risk of damage. Pick-and-place machines and vacuum pens are commonly used in manufacturing to reduce handling risks. Additionally, vision systems in pick-and-place machines help improve placement accuracy by recognizing package outlines or individual solder bumps. The geometry of solder bumps further aids in self-centering and alignment during PCB assembly.
As electronic components continue to shrink, manufacturing equipment also evolves to accommodate these changes.
Innovation follows a continuous cycle. Consumers demand feature-rich, compact products. Engineers work to balance these demands. The semiconductor industry continuously evolves to optimize packaging and functional integration. Once a new generation of products reaches the market, teams convene to brainstorm the next breakthrough, repeating this cycle.
TI’s advancements in semiconductor miniaturization—including selective functional integration, packaging optimization, and manufacturing improvements—provide engineers with more options for designing in an increasingly miniaturized world.
