FAQs

Answers to Your Microelectronics Questions

The world of microelectronics is highly technical, and it can be challenging to fully understand the details of each component. To help make this easier, we’ve compiled a list of frequently asked questions to provide information about some of the questions you might be wondering!

What is the difference between a stencil and a screen?

Stencils are used to print directly onto a PCB (on-contact printing). An image in a stencil consists of apertures (laser-cut, chemically etched, or electroformed) through a solid material, such as stainless steel.

In screen printing, a fine weave of stainless steel or polyester mesh is coated with emulsion, and the image is then exposed with a camera or light source. Screens have a bit of separation (off-contact printing) with the substrate, allowing the mesh to contact the printed surface as the squeegee passes.

General Questions

What type of files can I send for a screen or stencil?

We can use Gerber, DXF, or ODB++ file formats.

What types of reports can you send with my screen or stencil?

A conformance report is shipped with every stencil. Upon request, a “paste report” that includes area ratio, aspect ratio, and volume can be provided at no extra charge.

How long does MicroScreen maintain customer data?

We currently have files dating back to June of 2003. The MMSN number is unique to every stencil or screen and is the best way to reference any MicroScreen product. All data is kept in a corresponding directory.

Stencils

What is the smallest aperture size you can laser cut in a stencil?

Features down to .003” can be cut.

What options do you have for coatings?

We offer two types of nanocoatings. MicroGlide is an affordable, two-part wipe that can be applied to any stencil—old or new—to improve solder paste release. MicroGlide Platinum is a heat-fused nanocoating that is excellent for ultra-fine pitch printing and will not flake or chip off.

How should I clean my MicroGlide or MicroGlide Platinum coated stencil?

We offer a pre-saturated, heavy-duty stencil cleaning wipe that will not tear or leave lint behind.

What do I need to order a stencil?

At the very least, a paste layer. If this isn’t available, we can create it using other layers. A check plot in Gerber or PDF will be sent for approval prior to fabrication.

How can I optimize my stencil printing process?

Our technical experts can help with specific trouble areas to recommend proven component designs and modifications, foil thicknesses, and nanocoatings.

What is the lifespan of a stencil?

Many factors that vary with every stencil user make this question difficult to answer. According to IPC7525B Stencil Design Guidelines, Section 9 – End of Life, “ Stencils should be inspected periodically for damage that would contribute to decreased printing performance”

My paste layer is not arrayed. Can you work with what I have?

If other layers are panelized, we can panelize the paste layer. A drawing with measurements can be used to panelize the files; or, as a last resort, you can send us a PCB.

Screens

Can you recommend mesh type and emulsion thickness for my screen application?

Yes, we can look at your application and make recommendations from that to determine the desired wet-print thickness.

What is mesh equalization?

Mesh equalization is the process of filling the mesh opening with emulsion and building up a thick enough emulsion to equalize or smooth out the surface structure of the mesh. Additional emulsion is applied to match a customer specified emulsion build up or overall screen thickness.

What is the largest screen size you can manufacture?

Our advanced stretching systems accept frame sizes up to 70” x 102” and provide consistent, exact duplication of tension from screen-to-screen and stretch-to-stretch on both stainless steel and polyester mesh.

What is the smallest line/spacing you can resolve on a screen?

Using our standard mesh and emulsions we can resolve 25 micron lines and spaces. With specialty mesh and emulsions, it is possible to resolve down to 10 microns, sometimes less.

Want to speak directly with an expert?

Get in touch with our team today to learn more about the stencils and screens we offer!

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