SMD Stencils / Precision Stencils

SMD stencils serve as precise mechanical masks in electronics manufacturing. They ensure that solder paste or adhesive is applied accurately, consistently, and without errors to the contact areas of a printed circuit board. This optimally prepares the printed circuit board for subsequent automated component placement.

The thickness of the stencil determines the amount of paste applied and depends on the component size. Typical thicknesses range from 80 to 150 micrometers. While fine-pitch components require thinner stencils, larger components require thicker stencils. For adhesive application stencils, sheet metal thicknesses ranging from 200 µm to 400 µm are also used. We customize the dimensions according to customer specifications; our precision sheet metal comes in standard sizes of 610 mm x 850 mm.

In addition to standard stencils, KMLT^® offers numerous specialty designs for specific industrial requirements, including wafer bump stencils, stencils for flip-chip manufacturing, LTCC stencils, as well as stencils for adhesive application, placement, and inspection, and multi-panel stencils for simultaneously printing on multiple circuit boards on a single panel.

Instead of relying on fragile, mechanical step stencils, we at KMLT^® use software-based aperture modification in the CAM process, which is more precise and gentler on the material. In practice, locally reducing or increasing sheet metal thickness often leads to drawbacks such as uneven squeegee pressure, increased wear, and more difficult stencil cleaning. After close consultation with you, our CAM specialists therefore address the requirements of a complex mix of components in a significantly more intelligent way: Through targeted geometric adjustment of the apertures, we control the exact solder paste volume purely through the aperture design. Upon request, we can align your layout data directly with your individual process parameters in advance. This ensures you receive a completely homogeneous sheet that guarantees maximum service life, protects your squeegee, and delivers flawless results in a stable printing process.

Yes. KMLT^®’s high-precision laser cutting technology is optimized for extremely tight manufacturing tolerances in the micrometer range. Following individual technical consultation and a feasibility study, we manufacture highly specialized wafer bump stencils as well as stencils for flip-chip assembly with process reliability according to your specifications. Working directly with your developers, we perfectly tailor the exact aperture geometry and precise cutting angle to your paste viscosity and substrates. This guarantees clean, error-free release of ultra-fine printing media, even at the most demanding pitches.

• 1.4301 stainless steel: The durable and cost-effective standard for general applications in electronics manufacturing.
• FineGrain material: An innovative, ultra-fine-grained stainless steel sheet. It is a cost-effective alternative to nickel, produces smoother inner pad walls during laser cutting, and is recommended for high-density applications.
• Nickel: Offers maximum hardness and excellent paste release for highly critical specialty applications, but is more expensive.

KMLT^® manufactures frameless stencils with royalty-free perforations compatible with all commercially available quick-clamping systems, such as Alpha Tetra / DEK-Vector (KMLT^® System FM SS308), Mechatronics, and Quatroflex, as well as VectorGuard™ and ZelFlex.

To protect against cuts and to stabilize thin sheets of metal, KMLT^® recommends an edge guard in which the edges of the templates are bent at a 180° angle.

During electropolishing, the thin stainless steel sheet is immersed in an acid bath and connected as the anode. Under direct current, the micro-roughness is selectively removed electrochemically from peaks and edges. This results in ultra-fine deburring and extremely smooth inner edges of the pad.
Are the results comparable?
Yes, the functional printing results are absolutely identical. Although plasma polishing physically relies on a vapor-plasma skin and optically produces an even higher mirror-like gloss, this offers no measurable advantage when it comes to the mechanical removal of the solder paste. Traditional electropolishing delivers exactly the same practical result: The solder paste glides flawlessly out of the apertures along the smoothed fusion grooves, paste residues hardly adhere at all (which noticeably extends cleaning intervals), and the controlled removal preserves the stencil’s precise geometric tolerances.

Imaginative brand names do not optimize the printing process. While the market often promotes proprietary brand names such as “plasma coating” or similar pseudonyms, KMLT^® consistently focuses on differentiation through transparency. We describe the physical and chemical processes exactly as they are. Instead of vague plasma terminology, we use electropolishing and, for our nano-finishing, the certified and validated Aculon^® NanoClear^® system. For you as a customer, what matters isn’t a marketing term on the invoice, but measurable facts: minimized surface roughness and perfect release properties that ensure your process stability over the long term.

KMLT^® uses the special Aculon^® NanoClear^® sealant for this purpose. This hydrophobic/oleophobic coating ensures that solder paste residues adhere to the walls only minimally, if at all. This speeds up cleaning, ensures process repeatability, and remains reliable for tens of thousands of printing cycles. The coating can be renewed at any time.

Our CAM data optimization applies corrective measures even before laser cutting begins. By adjusting the area and aspect ratios and specifically modifying aperture geometries, we prevent typical defects in the SMT process. This has been proven to minimize the risk of solder bridges, solder balls, or the dreaded “tombstone effect” during the placement of microcomponents.

Our SMD stencils are manufactured from high-quality, thermally relaxed stainless steel sheets. International industry studies and expert panels (such as those on Circuitnet) estimate the purely material-related service life of stainless steel stencils under optimal conditions to be between 300,000 and over 500,000 printing cycles. The thermally relaxed, high-performance stainless steel we use provides the perfect mechanical foundation for this. In actual manufacturing practice, however, the actual service life is inextricably linked to the condition of the squeegee blades (squeegee life) and the process parameters. The stencil and squeegee form a direct friction system. A contact pressure minimized to protect the material prevents the apertures from premature wear caused by abrasive solder pastes and simultaneously extends the squeegee life. Even the smallest mechanical damage or nicks on the squeegee edge act like a plane and can prematurely destroy the stencil sheet. The combination of intact squeegees and gentle handling ensures the maximum service life of both components in everyday production.
To further optimize service life and cleaning intervals, we recommend combining electropolishing with our durable Aculon^® nano-coating. In addition, our material-friendly, burr-free edge protection safeguards the sheet from mechanical wear during clamping and unclamping.

Every order undergoes a thorough CAM review, which includes a comprehensive layout analysis to prevent printing errors, precise panel creation including visual markers (fiducials), and expert recommendations on materials and thicknesses tailored to the layout.

All standard CAD and layout file formats used in electronics manufacturing are supported, including Extended Gerber, Gerber X2, DXF, and DWG. When placing an order, please specify the desired material thickness, scaling specifications, the clamping system used, and any desired finishes.

In electronics manufacturing, every hour counts. KMLT^® combines highly automated laser systems with fast CAM processes. Once technical details have been successfully clarified and data approved, standard stencils go into production immediately and, upon request, can be delivered directly to your production line via express shipping. This is how we guarantee minimal downtime and maximum on-time delivery.

Yes. We know that the development phase and prototyping involve different budgets and flexibility requirements than mass production. KMLT^® offers high-precision, cost-optimized sample templates for research and development projects as well as small-batch production. You receive exactly the same industrial laser-cutting quality as with our production templates—without compromise—but precisely tailored to your prototype clamping systems.

Before final shipment, every laser-cut SMD stencil undergoes a comprehensive visual quality inspection using a scanner system to ensure absolute dimensional accuracy and that all pads are present and correctly positioned.