PCB Stencils, also known as SMT (Surface Mount Technology) templates, are a type of specialized tool used in SMT processes. During the surface mounting of components on a PCB, stencil printing is a crucial step. Placing the stencil above the empty PCB, as the squeegee moves, solder paste is forced through the holes onto the pads. Subsequently, through the following steps like pick & place and reflow soldering, the components are firmly attached to the pads. How is stencil printing achieved? This requires a well-designed stencil template.

In the traditional working mode, companies provide stencil design requirements, and the stencil manufacturer provides the completed design files for confirmation. Engineers manually inspect the design files, which is often time-consuming and inefficient. And it is also easy to overcome errors when checking large-sized PCBs or components with huge numbers, leading to potential inaccuracies and incompleteness. How can we achieve a fast, accurate, and comprehensive inspection of PCB stencil design? This is where Vayo’s stencil design check software comes into play.

This software primarily serves three purposes:

a. Rapid intelligent learning to build a digital SMT stencil library and establish internal company standards for SMT stencils.

b. Intelligent and rapid stencil design to reduce modification cycles and improve design proficiency.

c. Inspection of PCB stencil design, enabling quick verification of design discrepancies and adherence to design standards.

Today, our focus is mainly on the third function – the inspection of PCB stencil design. This inspection mainly includes two aspects. The first is to check the finished design against industry-standard specifications. And the second is to compare the design against the company’s own specifications.

Regarding the second type of inspection, a company must have its own opening library to conduct the comparison. Different companies have varying requirements for the inspection on the SMT stencil design. Some may only need the first type, while others require the second, and some need both. Vayo’s stencil software can accommodate different needs. Let’s list these two types of inspections and indicate important considerations.

Inspection 1: Checking against industry-standard specifications

Before conducting this inspection, we need to establish the corresponding inspection rules. Vayo’s software offers over 60 rules, allowing companies to conduct reviews based on their specific requirements. With a simple click, the software will thoroughly examine each opening detail according to the inspection rules, such as opening area ratio, aspect ratio, opening-to-board edge distance, etc. Differences that do not conform to the rules will be marked, allowing engineers to quickly identify and address discrepancies.

Inspection 2: Comparing against the company’s internal specifications

As mentioned earlier, before conducting this inspection, the company can use Vayo’s stencil software to establish its own centralized library. Once the library is complete, we can proceed to this step.

Input the PCB CAD data and the Gerber data into the software, then match the openings with the centralized library. There may be cases where certain components have no matching library, indicating that there is no opening information for those specific components in the digital library. In such cases, the software allows you to create a new opening and proceed with the comparison. After the comparison, there will be a generated result telling you the differences. Similar to the first type of inspection, engineers need to compare each difference one by one.

Considering the practical manufacturing conditions of the stencils, some differences can be ignored, such as differences caused by shared pads or avoidance routing. Engineers can edit the difference description in the software and output the comparison report.

By utilizing VSD’s stencil software, engineers can swiftly and accurately inspect their SMT stencil designs, identify design flaws early on, and promptly make corrections, ensuring high-quality stencil printing. Say goodbye to inefficient and error-prone manual inspections, and upgrade your inspection process immediately to experience the efficiency and reliability of VSD’s intelligent stencil software!