Guide to Cost Control and Risk Avoidance in the PCB Manufacturing Process
The essence of PCB end-to-end cost control and manufacturing risk avoidance is to achieve the necessary performance with minimal cost. This involves eliminating redundancy from the design stage, verifying functionality during prototyping, optimizing yield during pilot production, and leveraging economies of scale in mass production, forming a closed-loop management system. This approach ensures product quality while continuously reducing hardware R&D and production costs, thereby enhancing product competitiveness.
Risk avoidance in the manufacturing process is a crucial part of manufacturing cost control. Geyuan Electronics summarizes common risks encountered in over 30,000 projects as including: blindly using high-end processes, frequent rush prototyping, frequent design changes, selecting uncommon components, unreasonable panelization, neglecting DFM (Design for Manufacturing) leading to rework, and multiple small-batch replenishment orders. Avoiding these risks when collaborating with manufacturers on PCB procurement projects can reduce unnecessary expenses by over 30%. Furthermore, it’s essential to remember that different scenarios require differentiated cost reduction strategies. Individuals/startups should focus on standard processes, small-batch panelization, and leveraging first-order discounts; established companies should prioritize DFM optimization in R&D, end-to-end control, and bulk negotiation; and regular mass-production PCB projects should focus on economies of scale, process standardization, and supply chain integration.
Next, this article will mainly discuss common risks and quality issues that may arise during PCB manufacturing, and summarize methods for controlling PCB project manufacturing costs and managing risks. After reading this article, you will not only understand the common problems in PCB manufacturing, but also learn from our experience in controlling PCB manufacturing costs.
Common mistakes to avoid in PCB assembly and manufacturing
Discovering defects during PCB assembly and manufacturing not only hinders the entire process but also leads to costly redesign and testing cycles, increased warranty claims, and damage to brand reputation when the final product reaches the customer. Therefore, the Geyuan Electronics team has compiled a list of common mistakes to avoid during the manufacturing and assembly process of PCB projects.
test points
Adding hooks during the design phase of PCB manufacturing and assembly is a good practice, as it makes testing critical components much easier. Test points are locations on the circuit board where test signals are inserted and the circuitry is observed. Those who neglect such test points during the design phase are more likely to encounter component errors later on, which not only hinders the PCB assembly and manufacturing process but also leads to additional modifications and sometimes even a complete redesign.
Pollution risk
During PCB manufacturing, substances such as flux residue, fingerprints, cleaning agent residue, and acidic plating solutions can cause contamination, leading to problems such as electrical short circuits, open circuits, and corrosion. Therefore, it is essential to keep production areas clean and exercise extreme care when following handling procedures.
Material defects
Materials used in PCB manufacturing and assembly must be defect-free. Manufacturers must ensure that materials are purchased from reputable suppliers who will not compromise on quality. Inferior materials may contain insufficient resin, pinholes, nodules, etc., which can cause problems later on.
Changes in routine processes
If critical factors such as inaccurate or imprecise temperature, substandard drilling rates, uneven lamination, and insufficient storage facilities occur and exceed control limits, variations in routine processes can lead to PCB defects. Therefore, to prevent such problems, statistical methods can be used to detect when these factors deviate from tolerable limits. Control charts are also an excellent tool for tracking factors and minimizing problems associated with variability.
Dimensional defects
Paying attention to PCB dimensions is crucial, as accurate dimensions are essential for proper PCB operation. Common dimensional issues include tilting (inner layer displacement due to misalignment between different layers), incorrect patterning (incorrect layer alignment, resulting in holes not being arranged according to a specific pattern), incorrect drilling (drilling holes in locations different from the intended ones), and overall intolerable space and routing, which can lead to short circuits. To prevent such problems, manufacturers must pay attention to dimensional accuracy and perform multiple calculations before finalizing the dimensions.
Electroplating defects
The plating used on PCBs must be of high quality and free from any defects. Defects such as nodules (protrusions on the copper plating surface), pits (gaps and depressions on the plating surface), dull textured plating, and plating that is thinner than required can all lead to poor connections or over-soldering.
Drilling defects
Drilling defects, such as contaminants (resin residue left around the hole after drilling), substandard holes (inaccurate diameter or imperfect roundness), rough hole edges, and incorrect hole centering, can lead to incorrect bonding between layers. Therefore, not only must drilling be completely precise, but the hole dimensions must also be accurately calculated first.
Human error
Sometimes, human error can damage PCBs. For example, a machine operator might integrate defects into the PCB, incorrectly load the board into the plating tank, use the wrong size drill bit, or improperly store finished boards. All of these errors can be avoided by applying adequate training programs, proper work instructions, redundant verification of machine settings, and increasing automation.
Insufficient space between the edge and the trace
If the spacing between edges and traces is not maintained optimally in the circuit layout, exposed copper conductors may be partially or even completely cut off. This can result in exposed copper and burrs around the edges.
Improperly handled copper sheets
During the printing process, thin sheets of copper called copper fragments are formed. In some cases, these fragments can fall into the plating bath and stray anywhere on the circuit board, potentially causing short circuits. Sometimes, if these photoresist fragments are removed, these scattered copper fragments can threaten the functionality of the circuit board. Therefore, it is best to handle them carefully to protect the circuit board.
Screen printing error
Screen printing is the final step in the PCB manufacturing and assembly process. If the screen printing overlaps with pads, PCB board, holes, etc., it may hinder subsequent assembly processes.
Purchase the wrong components
Sometimes, choosing the wrong components can affect the assembly process. It’s best to choose standard components because they are available from various suppliers. Custom parts can only be purchased from a limited number of suppliers. Therefore, they are not feasible for large-scale PCB production and would significantly increase costs.
Open circuit and short circuit
Obviously, a printed circuit board with open or short circuits cannot function as any electronic product. Although PCB suppliers should have performed 100% open/short circuit testing, very small connections that could cause short circuits may go undetected, or boards with open/short circuit issues may be mixed in with good boards.
Poor welding
Sometimes, PCB assembly manufacturing fails to solder electronic components to a good condition, for example, by using too little or too much solder, which can lead to serious problems in the application field.
Insufficient insulation
Ensuring proper insulation between metal traces is perhaps one of the most critical areas in printed circuit board manufacturing. On the other hand, poor insulation can have catastrophic consequences. Some examples include one trace continuing to carry a low-voltage current, while another example is a high-voltage current passing through a trace but forming an arc that damages the entire system.
Insufficient inspection and testing
Quality control in the PCB manufacturing process is achieved through numerous tests. For example, micro-dicing and inspection involve cutting a PCB and examining each layer under a microscope. In addition, thermal testing, vibration testing, and aging testing are conducted to ensure the circuit board functions perfectly under extreme conditions. This thorough testing and inspection allows PCB manufacturers to ensure their PCBs meet standards and to identify any future defects.
Various faults and causes of PCB boards during the manufacturing process
While establishing successful control measures in PCB manufacturing projects is crucial, a comprehensive understanding of the root causes of PCB failures is essential to mitigate risks arising from manufacturing issues. The Geyuan Electronics team summarizes the key factors contributing to PCB failures during the manufacturing process.
| PCB bare board related defects | There may be minor issues that PCB manufacturers cannot detect. For example, a small connection between copper wires might pass electronic testing but fail in the final test after assembling electronic components. |
| PCB assembly and soldering related defects | Improper soldering techniques can lead to poor connections on printed circuit boards. Ensuring proper component soldering can usually prevent these problems. |
| Different usage environments | Although PCB manufacturers conduct thorough inspections and tests before delivery, it is still impossible to 100% simulate the usage environment, such as heat, cold, vibration, humidity, etc. |
| Mechanical failure | These include equipment defects, line spikes, and equipment aging that leads to manufacturing failures, all of which result in circuit board failures. |
| Environmental factors | Therefore, circuit board performance capacity is more likely to decline when affected by adverse atmospheric factors such as raindrops, high humidity, and degradation substances (strong sunlight, corrosives). |
| Mechanical stress | Excessive mechanical stress caused by vibration, bending, or impact can lead to mechanical failure of circuit board connectors. |
| Electrical overload | Applying a high current to the PCB will cause operational interruptions and damage to PCB components. |
| Design error | PCB errors can affect the quality of board operation because errors related to incorrect trace widths and routing can indeed occur. |
| EMI/EMC interference | Failures in printed circuit boards can be traced back to non-compliance related to EMI and EMC. |
Methods for PCB manufacturing cost control and risk avoidance
PCB cost control is not just a matter of a single prototyping attempt, but rather a comprehensive management process from design, prototyping, pilot production to mass production. Effective end-to-end planning can reduce overall hardware costs by 20%-50%, while simultaneously improving yield and shortening cycle times. Below are methods summarized by the Geyuan Electronics engineering team to mitigate various manufacturing risks while maintaining PCB manufacturing cost control.
Optimize PCB design
The design phase is the starting point for cost control, determining 70% of the final cost. We adhere to three principles: minimizing the number of layers, minimizing area, and standardizing processes. We use 2 layers instead of 4, and 4 layers instead of 6, reducing the number of layers through layout optimization; compact routing reduces area, keeping it within 10×10cm to enjoy standard pricing; trace width and spacing ≥6/6mil, vias ≥0.3mm, standard FR-4, and lead-free solder plating, avoiding all process markups.
Simultaneous design of DFM and DFA
Implementing simultaneous Design for Manufacturing (DFM) and Design for Assembly (DFA) ensures both manufacturability and assemblability. Standardizing device packaging reduces BOM types and lowers surface mount component rework costs; avoiding dense-pin and micro-sized components improves SMT yield; simplifying structures reduces assembly steps. Spending an extra day optimizing during the design phase can reduce subsequent rework costs by 30%.
Functional verification using PCB samples
The prototyping stage focuses on functional verification, rejecting excessive performance. Lead-free solder coating is used for surface treatment, instead of immersion gold; copper thickness is 1oz, instead of thick copper; conventional through-holes are used, instead of blind or buried vias; green solder mask is used, instead of special colors. Only necessary processes are added for high-speed, high-frequency, and high-current scenarios; everything else is simplified.
Detailed manufacturability analysis (DFM)
Choose factories that offer free DFM pre-screening to identify potential issues early and avoid prototyping failures. Produce 10-20 samples at a time to spread engineering costs, meet testing and backup needs, and avoid reordering. Place orders with standard lead times to avoid rush fees and make R&D budgets more efficient.
Optimize manufacturing yield during trial production phase
During the small-batch trial production phase, the focus is on optimizing yield and smoothly transitioning to mass production. After successful prototyping, a trial production of 50-100 pieces is conducted to verify process stability and yield. Any issues discovered are promptly addressed by adjusting the design to avoid scrapping during mass production. The trial production phase also involves optimizing panel layouts to improve material utilization, laying the foundation for cost reduction in mass production.
Use general-purpose materials
Component selection should adhere to the principles of universality and substitutability, avoiding uncommon, discontinued, and high-margin materials. BOM optimization can reduce PCBA costs by 60%-80%, prioritizing the use of 0402 and 0603 general-purpose packages, and diversifying supply sources to reduce the risk of stockouts.
Mass production increases economies of scale and reduces costs
During mass production, extreme cost reduction is achieved through economies of scale, process standardization, and supply chain optimization. For batches of 1,000 pieces or more, the unit price can be reduced to 10%-20% of the sampling price; panel utilization is increased to over 90%, further reducing material costs; and long-term agreements are signed with factories to obtain price discounts of 10%-20%.
Avoid frequent changes to design and manufacturing processes
Standardizing processes avoids frequent changes, as each design change necessitates the rework of stencils, programs, and fixtures, increasing hidden costs. Establishing a standardized design library allows for the reuse of mature modules, reducing redundant prototyping and improving R&D efficiency.
Choose a one-stop PCB manufacturing plant for cooperation.
Supply chain management is equally crucial. Choosing a one-stop PCB+PCBA factory reduces communication costs and shipping expenses, and avoids coordination errors between multiple suppliers. Centralized procurement of boards and components allows you to enjoy bulk discounts and reduce material costs. Establishing safety stock helps you cope with the risks of price increases and stockouts during peak seasons.
Manufacturing quality problems caused by PCB design and their solutions
Many engineers, after completing the schematic design for a PCB project, often rush into the routing phase, neglecting to consider the feasibility of the manufacturing process. Designing entirely without considering the actual manufacturing capabilities of the PCB manufacturer can easily lead to situations where, after production, the PCB cannot be manufactured, or some functions are completely unusable in mass production.
Therefore, after the PCB schematic design is completed, it is essential to conduct a preliminary check against the process specifications of the cooperating manufacturer: confirm that parameters such as minimum line width and spacing, via size, and solder mask precision are within the manufacturer’s capabilities, thus avoiding the embarrassment of “designing but not being able to manufacture,” and ensuring the processing quality and process feasibility of the circuit board from the source.
Furthermore, signal integrity is a core pain point that cannot be avoided in PCB design. Issues such as reflection, crosstalk, and signal jumps are problems that almost every hardware engineer has encountered. To avoid these problems, one cannot rely solely on experience and judgment during routing. Optimization should be integrated into the entire design process: prioritize the use of reasonable connection topologies, coupled with correct capacitor placement, microstrip and stripline design rules, and conduct simulation analysis of signal transmission on high-speed interconnects in advance to anticipate potential risks such as signal distortion and impedance mismatch. Solve signal integrity problems from the routing stage, rather than spending a lot of time troubleshooting during the debugging stage.
Another easily overlooked problem is the mixing of analog and digital circuits. Many engineers fail to clearly define the two areas during routing, and overlapping traces can easily mask problems in a single inspection stage, leading to failure to detect faults in a timely manner or even misdiagnosis and mistreatment. For example, interference between analog and digital signals can cause offset shifts and signal deviations, ultimately resulting in a significant increase in the calculation errors of integrated circuits, causing the final PCB product’s accuracy to fall far short of design requirements. To solve this problem, physical partitioning of the analog and digital areas is necessary during the layout phase, clearly distinguishing and isolating the switching control and load connections of the two types of circuits, thus spatially cutting off paths of mutual interference.
Geyuan Electronics – Helping you control PCB manufacturing costs and mitigate risks
Geyuan Electronics’ team of experts and experience helps you make better decisions and solve problems. Our PCB assembly and manufacturing capabilities, coupled with years of experience, not only help you control the overall cost of PCB manufacturing and assembly but also help you mitigate potential manufacturing risks in new projects. Our prototyping PCB assembly service allows for the testing and validation of all designs before full-scale production. Furthermore, our in-house quality control measures ensure that the final product meets high standards. Leveraging Geyuan Electronics’ mature manufacturing facilities and technologically advanced production environment, you can address the challenges of new projects. Moreover, Geyuan Electronics’ custom PCB manufacturing options allow you to tailor designs to specific requirements, while our scalability and production volume knowledge help plan for future needs, control project costs, determine pricing structures, manage project budgets, and control total project costs.
Summarize
Printed circuit board (PCB) manufacturing is a complex process that integrates precision chemistry, physics, and electronic engineering. A thorough understanding of every step from design to finished product, including common problems and solutions in PCB manufacturing, helps engineers optimize designs from the outset, communicate effectively with suppliers, and control costs and mitigate manufacturing risks.
Therefore, to control manufacturing costs and mitigate risks in PCB projects, when selecting partners, in addition to considering conventional factors such as quality, price, and speed, it is even more important to focus on whether they can empower projects through technological and service innovation. Platforms like Geyuan Electronics, which not only excel in standard manufacturing but also lower the barriers to high-end design through strategies such as “free in-disk vias,” are undoubtedly ideal choices to help you accelerate innovation and stand out in a fiercely competitive market.