Making PCBs progressively smaller is an ongoing trend resulting from products containing them having tinier form factors.  These smaller components often come with PCB design challenges that can subsequently affect inspection.

1. The main PCB design challenges associated with miniaturization

Traces: The size associated with PCB miniaturization means designers must work with much smaller trace geometries, causing reductions in width and thickness.

Vias and Microvias: Since the overall PCB is comparatively tinier, the vias have significantly smaller diameters. The small vias required by miniaturized PCBs make it challenging to coat the hole wall thoroughly, compromising performance and functionality. Designers must consider the thickness of the PCBs to determine the minimum possible diameter of the vias.Some projects may warrant choosing microvias, which are exceptionally small and added to the PCB with laser drills. Designers often select microvias to establish connections between multiple layers of a PCB. Blind and buried vias also support PCB miniaturization by optimizing the board size and keeping the design at the proper proportions. While a blind via connects an outer layer with at least one inner layer, a buried via connects multiple internal layers.

2. PCB miniaturization and flexibility

Some researchers have even explored whether 3D printing could shorten production time frames and meet increased demands for rigid and flexible PCBs.

Flexible PCBs work well for tiny devices, along with medical machines or those that must conform to someone’s body to get accurate readings. For example, smartwatches and home heart rate monitors used by many exercise enthusiasts often have flexible PCBs.

3. The impact of PCB miniaturization and flexibility on inspections

However, many manufacturers use high-tech processes to accelerate quality control practices and increase accuracy. For example, X-ray machines used for PCB inspections fall into two categories — 2D and 3D inspection tools that work online or offline.

A 2D system shows both sides of the PCB simultaneously, similar to an X-ray machine that checks human bones. A 3D system works by creating groups of 2D cross-sections to complete the image. Online systems need active internet connections to work, but offline ones do not.

People involved with PCB inspections may also need to change their fundamental processes and checklists.

Miniaturized PCBs have higher component densities  than their larger counterparts.

People producing flexible PCBs must use a different soldering method than when manufacturing rigid ones.

4. Staying aware of market demands

Most customers purchasing today’s printed circuit board-containing products have little or no direct experience with solving PCB design challenges. However, these users are often the first to notice performance issues caused by flaws not identified during inspection processes. So, although users don’t know all the complexities associated with designing PCBs, they’ll experience the results of design-based shortcomings.

However, in the best scenarios, miniaturized PCBs get careful attention through the design, manufacturing and inspection stages. When that happens, there’s a much higher chance of the products being high-performing and free of flaws — whether they’re rigid or flexible.

A final thing for engineers, designers and manufacturers to remember is that PCB development is a fast-moving area, largely due to the technological advancements in the products that require these components. Staying aware of PCB innovations, design improvements, and new inspection possibilities will help people get the best results and maintain a tight quality control program.