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SMT Stencil Series

Evolution of Stencils

Stencils were originally made of screen mesh and were commonly referred to as screens or masks at that time. They started with nylon (polyester) mesh. Later, due to durability concerns, iron mesh and copper mesh appeared, and finally stainless steel mesh. However, regardless of the material, these early screens all suffered from inconsistent aperture definition and low dimensional precision.

As SMT technology advanced and precision requirements increased, metal stencils emerged. Due to material costs and manufacturing constraints, the earliest metal stencils were made of iron or copper. However, due to their susceptibility to corrosion, these were eventually replaced by stainless steel stencils — the standard in modern SMT production today.

Features of SMT Stencils

Precise aperture positioning with burr-free aperture walls; aperture shapes are customized to match specific component pad designs.
Frame sizes are available in standard dimensions as well as fully custom specifications to meet customer requirements.
A range of stencil thicknesses is available to accommodate different types of solder paste and surface mount adhesive (SMA).

Nano-Coated SMT Stencil

Overview

With the rise of increasingly miniaturized, sophisticated, and high-precision components in electronics, nano-coated SMT stencils have emerged to meet ever-higher quality demands in SMT production. The application of nanotechnology delivers outstanding performance in continuous solder paste printing, consistent print formation, and yield improvement — making nano-coated stencils particularly indispensable for fine-pitch and high-precision components.

In response to market demand, we offer professional nano-coating solutions and nano-coated SMT stencil manufacturing services for customers worldwide, helping achieve higher solder paste print quality and improved production yields.

As electronic products continue to evolve toward portability, miniaturization, and greater connectivity, the surface mount technology of electronic components faces increasingly stringent demands. New high-density components such as BGA and COB are constantly emerging, with component pin pitches becoming increasingly fine — ball pitches below 0.40 mm are now commonplace. At the same time, expanding production volumes place greater demands on stencil printing consistency. Conventional SMT stencils can no longer meet these requirements. High-precision nano-coated SMT stencils represent the solution the industry needs to address the growing demand for ultra-fine precision manufacturing and ensure consistent product quality.

Nanotechnology has now been widely applied to laser steel stencils. Using a special process, nano steel stencils modify the crystal structure on the non-printing side of conventional electro-polished steel stencils and deposit a metal coating of approximately 500–1000 nanometers. This increases the hardness of the steel sheet by 10%–30% (reaching 400–450 HV). In addition, the nano-coating features super-hydrophobicity and self-cleaning properties, which reduce solder paste residue on the backside and lower cleaning frequency. The cleaning interval can be improved from every 3–5 boards to every 20–60 boards. For high-precision products such as mobile phones, cleaning can be performed every 6–15 boards without affecting printing quality.

Superhydrophobic Surface
The nano-treated back surface becomes superhydrophobic, giving the SMT stencil effective self-cleaning properties. This greatly reduces the cleaning frequency of the stencil and improves production capacity.Depending on different products, the recommended cleaning parameters are:
•Stencil wiping frequency: every 20–60 pieces
•Stencil cleaning frequency: every 12–24 hours
Print Formation & Solder Paste Release
Following nano-treatment of the aperture walls, solder paste residue inside the apertures is significantly reduced while paste release volume is markedly increased, resulting in a well-defined, brick-shaped solder paste deposit profile. Perfect solder paste print formation enhances the first-pass yield (FPY) of products.Tests show that with the same aperture design, solder paste release volume can be increased by approximately 10%.
Durability & Quality Consistency
The ultra-thick nano-coating (500–1000 nm) is the core technology behind nano-coated SMT stencils, serving as the key to ensuring consistent, high-quality printing output over time. These stencils have a proven track record of 130,000 effective print cycles, and their extended service life is one of their most significant advantages.
Improved Stencil Tension
Nanotechnology treatment is applied to the surface of laser-cut SMT stencils while fully preserving their high-precision aperture dimensions and positional accuracy. This treatment transforms the material's crystal microstructure, significantly improving strength, hardness, and toughness, resulting in a notably extended service life. In addition, overall stencil tension is further enhanced.

Step Stencil

A step stencil is manufactured with two or more different thicknesses on the same plate. It is designed to accommodate PCBs with mixed large and small components on the same side, while ensuring excellent soldering quality throughout. To achieve precise solder volume control, different paste thicknesses must be printed in different areas of the same stencil — this requirement led to the development of the step stencil, which features STEP-UP (locally thickened) and STEP-DOWN (locally thinned) zones.

A STEP-UP design increases solder paste deposit volume in the thickened areas to compensate for uneven component lead heights, while a STEP-DOWN design reduces paste volume to prevent solder bridging in fine-pitch components.

Should the step be on the top or bottom surface?

A step on the top surface may cause smearing or print bleeding in the squeegee direction.
A step on the bottom surface may result in insufficient sealing contact between the stencil and the PCB surface.

If the area surrounding the step has no components or only widely spaced components, both STEP-UP and STEP-DOWN configurations are applicable.

Precision Jigs & Fixtures

We provide custom manufacturing services for a wide range of precision jigs and fixtures, including printing jigs, PCBA test fixtures, reflow fixtures, SMT placement jigs, aging jigs, hand soldering jigs, power supply test jigs, and process tooling fixtures. Please feel free to contact us for more information.

All products are custom-made. Pricing is determined based on your drawings and technical specifications. If you are interested, please share your relevant drawings and requirements so we can prepare a tailored quotation for you.

Process

To get started, please provide:

Gerber / CAD data (to ensure 100% accuracy of probe point placement).
Physical samples and qualified PCBA boards for testing reference.
Your operation flow and functional test requirement list.

This allows us to fully understand your testing requirements and workflows, enabling us to design professional, customized solutions that precisely meet your needs.

Our Jig Engineering Department professionally designs and manufactures a full range of jigs: soldering jigs, printing jigs, wave solder pallets, SMT placement jigs, test fixtures, post-soldering jigs, screen printing jigs, dispenser jigs, and screw-fastening jigs.

Our jigs are manufactured using world-renowned engineering materials, including Roechling and Isola synthetic stone as well as fiberglass composite boards, all known for their excellent performance under high-temperature conditions. Machined on high-precision CNC equipment, our jigs deliver outstanding performance, consistent dimensional accuracy, anti-static properties, exceptional stability, and long-term durability.