SMT Stencil

Yt-electronic manufactures solder paste stencils for SMT.

Stencils (also called SMT stencils) are essential for transferring the correct amount of solder to the correct locations on circuit boards that are bare and ready for assembly. Stencils can ensure an optimal electrical connection and the best solder paste quantity with ease. Solder stencils allow you to easily apply solder over PCB openings using metal squeegees.

We offer two types of stencils based on the SMT manufacturing technology: chemical-etched stencils and laser-cut stencils.

Laser-Cut Stencils

The openings on stainless steel are laser cut. This type of stencil is generally produced quickly and with a high level of precision.

• Advantages: High accuracy, barely affected by objective elements. Trapezoid opening is beneficial for demoulding.

• Disadvantages: low production speed.

Chemical-Etch Stencil

Acid is used to etch the openings into the metal. This type of stencil is usually better for protecting the material's temper and hardness.

• Advantages: low cost, high production speed and one-time manufacturing.

• Disadvantages: tends to form sand-clock shape or large holes; multiple manufacturing stages with accumulating mistakes; not suitable for fine pitch stencils.

How Do I Determine the Size of the Stencil?

The PCB stencil size is divided into two parts, internal size and total size. The internal size corresponds to that of the PCB, ready for assembly. Overall size is the size which fits within the printer parameters. Both sizes must be designed accurately for the stencil to perform its full functions.

The internal size of the stencil can be calculated by following this rule:

The width of the stencil is equal to the PCB's width plus 100mm, while its length is equal to PCB's length + 100mm

The width of the frameless stencil is 200mm plus the PCB's length.

If, for example, the size of a circuit board is 50*50mm then its frameless stencil size should be 250*250mm.

Before the automatic printer, manual solder paste printing was used in SMT assembly. It is easy to use and remember. You can say that different PCB size leads to different internal stencil sizes.

It's a relatively good option when it comes to an automatic solder paste print. The size of the stencil is determined by the parameter limits of the equipment. This means the printer. Different printers feature different parameter regulations. Yt-electronic's printer is compatible with stencil sizes of 650mm*650mm and 736mm*736mm.

PCB designers should focus on the internal size of stencil. They don't have to worry about its overall dimensions, as it is usually determined by printer parameters in your contract assembly workshop.