Shenzhen Juehui Weiye Circuit Co., Ltd. specializes in prototype fabrication and small‑to‑medium‑volume production of high‑precision multilayer PCBs. Our services include fast‑turn PCB prototyping, SMT stencil assembly, DIP through‑hole soldering & component insertion, component sourcing, and finished‑product assembly — delivering one‑stop PCBA turn‑key solutions.

We serve diverse industries including medical instruments, industrial control, automotive electronics, telecommunications, artificial intelligence, security electronics, new‑energy applications, consumer electronics, AI systems, and military‑grade projects. Our facility adopts automated and digital‑managed production lines, enabling full traceability from raw‑material board incoming inspection to finished‑product delivery.

During daily manufacturing operations, we receive a wide variety of PCB design files and frequently observe designers making different process‑related mistakes. Below are the seven most prevalent PCB design issues encountered in real‑world production, explaining the root causes and corresponding solutions.

Pitfall 1: Arbitrarily modifying designs to save space without manufacturability considerations

In production communication, we often encounter designers who believe that a design is manufacturable as long as it passes EDA software checks. To achieve smaller dimensions and better mechanical fit, they tend to push design parameters to risky limits.

This is a misconception. PCB manufacturing equipment and processes have hard limits. Excessively fine traces or undersized vias frequently cause production defects such as etching‑induced short‑circuits or broken drill holes, resulting in drastically reduced yield. High rework costs or even full‑batch scrap may occur in severe cases.

Best Practice: Consult your PCB manufacturer upfront to confirm process limits (minimum trace width, minimum hole size, etc.). Avoid blind pursuit of miniaturization. Strike a balance between mechanical constraints and manufacturing feasibility. Collaborate with mechanical engineers to optimize specifications when compromises are necessary.

Pitfall 2: Relying solely on default software pad libraries with no adjustments

Many engineers take shortcuts by using default pad libraries provided by EDA tools, assuming they work for all component types with no manual tuning required.

This approach is incorrect. Default pads do not account for real‑world SMT placement accuracy and soldering requirements. Improper pad dimensions for small components may trigger the Manhattan effect (component tombstoning), cold joints or poor solder adhesion, leading to intermittent contact failures in the field.

Best Practice: Adjust pad dimensions and spacing according to component datasheets, and optimize based on your manufacturer’s SMT process capabilities. For high‑power or high‑frequency devices, prioritize thermal performance by adding thermal pads and thermal vias where needed.

Pitfall 3: Using 90‑degree right‑angle trace bends under the assumption of no functional impact

Some designers treat right‑angle bends merely as an aesthetic issue, believing they have no negative impact on circuit performance or manufacturing and skip arc‑shaped trace routing.

This practice is inadvisable. Right‑angle corners create two major problems:

First, etchant solution tends to get trapped at sharp corners during fabrication, gradually eroding copper traces and causing trace thinning or open circuits.

Second, signal integrity suffers, especially for high‑speed circuits. Right‑angle corners introduce signal reflection and increased noise, triggering product malfunctions.

Best Practice: Route traces with 45‑degree angles or smooth arcs wherever possible. If space constraints force near‑right‑angle transitions, apply chamfering to reduce etchant retention and signal interference. Double‑check designs for any sharp‑angled traces.

Pitfall 4: Selecting surface finishes purely based on cost without evaluating operating environments

Some engineers view surface finish only as anti‑tarnish protection for copper and opt for the lowest‑cost option, without considering whether the product will operate in humid conditions or handle high‑frequency signals.

This is a critical mistake. Different surface finishes deliver vastly different performance. For example, tin‑lead HASL used on high‑frequency hardware degrades signal transmission performance. Ordinary OSP finishes deployed in humid environments are prone to oxidation and poor solderability, shortening product service life.

Best Practice: Choose surface finishes matched to application scenarios and performance requirements. Select ENIG for high‑frequency circuits; ENIG or ENEPIG for humid‑environment applications; HASL for general low‑frequency circuits to balance cost and quality.

Pitfall 5: Over‑reliance on auto‑routing for error‑free, efficient layout

Many designers believe auto‑routing delivers high‑efficiency, error‑free results and can fully replace manual layout work.

This is not realistic. Auto‑routers work strictly according to algorithms and cannot account for every practical detail. They often produce redundant traces, insufficient clearances, and mismatched signal impedances. Critical high‑speed and differential signals cannot be precisely handled by auto‑routing alone, which may degrade signal integrity and trigger rework.

Best Practice: Prioritize manual routing, and treat auto‑routing as an auxiliary tool. Manually route critical nets including high‑speed signals, differential pairs and power rails. Auto‑route general low‑speed signals, then conduct manual reviews to correct unreasonable layout artifacts.

Pitfall 6: Arbitrary via placement, treating vias merely as inter‑layer connections

Some engineers regard vias only as simple inter‑layer interconnects, setting via sizes and positions arbitrarily with little attention to detail.

Poor via design brings multiple risks. Undersized vias with thin copper plating may suffer drill breakage or weak plating, causing inter‑layer opens. Vias placed too close to traces or pads risk short‑circuits. In high‑speed circuits, vias degrade signal integrity; excessive vias also drive up manufacturing costs.

Best Practice: Specify via dimensions in accordance with manufacturing rules, avoiding overly small or oversized vias. Position vias away from trace corners and pad edges. Adopt blind/buried vias for high‑speed designs to mitigate signal degradation, and keep via counts under control.

Pitfall 7: Focusing only on circuit functionality while ignoring manufacturability and assembly

Some engineers assume that as long as the PCB fulfills electrical functions, manufacturing‑related adjustments can be handled on the production side, without considering assembly ease.

This is another common pitfall. Designs that overlook production and assembly requirements create numerous downstream issues. Components placed too close to board edges cannot be picked‑and‑placed by SMT equipment; missing test points complicate product validation; unclear silkscreen markings lead to component misplacement and low assembly yield.

Best Practice: Factor manufacturing, assembly and test requirements into early‑stage design. Maintain adequate clearance between components and board edges, reserve sufficient test points. Ensure silkscreen labels are legible and consistent with BOMs and drawings. Align with manufacturing and assembly teams early to validate design feasibility and prevent costly rework.

Closing

In short, PCB design must be manufacturability‑oriented. Avoiding these seven pitfalls reduces development headaches, improves production yield and enhances product reliability. Both design and manufacturing require attention to fine details and close cross‑team communication to achieve high‑quality PCB results.