A request for “micro holes in metal foil” is not enough for a reliable quotation. The same hole diameter can behave very differently when the foil thickness, alloy, pitch, open area, pattern size and inspection method change. Buyers get faster and more comparable quotations when they describe the function of the array and identify which dimensions control performance.
Quick answer
A complete micro hole array RFQ should include material grade, foil thickness, overall part size, hole shape, nominal hole size, pitch, pattern area, number of holes, minimum web, edge distance, acceptable taper or recast, flatness condition, inspection method, quantity and required documents. Do not ask only for the “smallest possible hole.” The usable process window depends on the complete part.
Finalfoil reviews micro hole projects for stainless steel, titanium, nickel, copper and specialty metal foils using femtosecond, picosecond and other precision laser routes. Feasibility is assessed against the current drawing and acceptance method rather than a fixed universal size claim.
Start with the function of the micro holes
A micro hole array may meter a fluid, filter particles, generate droplets, control airflow, create an optical aperture, support a deposition process or form a sensor element. These functions do not share the same acceptance criteria. A filter may prioritize open area and blocked-hole rate. A nozzle plate may prioritize flow consistency. An optical aperture may prioritize position, shape and edge condition. An atomizer mesh may require the customer to evaluate the final spray behavior.
State the application in the RFQ even if the drawing is confidential. A short functional description lets the engineering team ask relevant questions without requiring disclosure of the entire product.
The seven dimensions that define an array
| Specification | What to show | Why it matters |
|---|---|---|
| Hole geometry | Diameter or width, shape and orientation | Controls toolpath, energy distribution and inspection |
| Pitch | Center-to-center spacing in each direction | Defines web width and heat accumulation risk |
| Pattern area | Rows, columns, zones and boundary | Affects cycle time, distortion and sampling plan |
| Web or bridge | Minimum metal remaining between features | Influences strength during processing and use |
| Edge distance | Distance from holes to the outer profile | Helps preserve handling strength and flatness |
| Foil thickness | Nominal value, tolerance and measurement basis | Changes aspect relationship and process parameters |
| Datums | Reference edges, fiducials or locating holes | Makes array-position inspection repeatable |
If holes are not identical, supply a zone map or machine-readable pattern file. Screenshots and raster images can hide dimensional errors and should not be the only geometry source.
Material selection changes the process window
Stainless steel foil is widely considered for filters, masks, nozzles and scientific apertures because of its strength and corrosion behavior. Titanium foil may be selected for low mass, corrosion resistance or application compatibility. Nickel foil appears in battery, electronic and chemical environments. Copper foil is valuable when electrical or thermal conductivity matters, but its thermal and optical behavior requires a different laser review. Refractory and specialty metals introduce their own handling and process considerations.
Specify the exact grade whenever possible. “Metal foil” and “stainless foil” are search terms, not complete purchasing specifications. Include temper, surface condition, coating or passivation, and whether the material must be supplied with an MTC or CoA.
Browse the metal foil materials database or begin with 316L stainless steel foil when corrosion resistance and documentation are important.
Edge quality must be described, not assumed
Terms such as clean, burr-free and perfect are difficult to inspect unless they are tied to a method and acceptance limit. Depending on the process and material, the relevant observations may include entrance and exit dimensions, taper, circularity, recast, oxide, discoloration, attached debris or local deformation. Not all of these matter to every application.
Tell the supplier which side is functional, whether the foil will contact another surface, and whether post-process cleaning is allowed. If the customer will inspect by microscope, optical measurement, SEM, flow test or another method, name that method during quotation. Agreement on measurement prevents a part from being acceptable under one method and rejected under another.
Why ultrashort-pulse laser processing is considered
Mechanical punching can be efficient when tooling and geometry are suitable, but very thin webs and small repeated features can challenge tool wear and deformation control. Chemical etching can process repeated flat patterns but adds phototool, chemistry and undercut considerations. Laser drilling is tool-free and supports rapid pattern revisions.
Femtosecond or picosecond processing may reduce the thermal load compared with longer-pulse methods and can support fine features in thin materials. The result still depends on wavelength, pulse strategy, focus, assist environment, fixturing and the foil itself. This is why Finalfoil treats the micro hole drilling service as an engineering review rather than a catalog promise.
Plan inspection before production
An array can contain hundreds or thousands of openings, so inspecting every dimension on every hole may be impractical. Define whether the project needs first-article inspection, sampled measurements, full visual screening, blocked-hole detection, open-area calculation or functional testing. Identify critical zones separately from noncritical regions.
For a prototype, inspection should answer the design question. For a production project, it should support repeatable acceptance. Ask for sample images or measurement output only where it helps the decision; documentation that does not connect to a requirement adds cost without increasing confidence.
RFQ checklist
- Application and functional purpose of the array
- Metal, grade, thickness, condition and surface requirements
- Hole geometry, pitch, pattern area, web width and edge distance
- Outer profile, datums, fiducials and orientation
- Critical edge characteristics and permitted cleaning
- Inspection equipment, sampling plan and acceptance method
- Prototype quantity, expected production quantity and revision status
- DXF or DWG geometry plus a dimensioned PDF
- Required material and inspection documents
Frequently asked questions
What is the minimum micro hole Finalfoil can produce?
There is no responsible single answer for every metal and drawing. Send the material, thickness, pattern, quantity and inspection requirement so the current technical route can be evaluated.
Should I specify open area or only hole diameter?
If flow, filtration or transmission matters, specify both the individual geometry and the required array-level performance or open-area target.
Can a prototype use a different material from production?
Sometimes, but the substitute can change cutting behavior and functional results. Record the substitution clearly and decide what the prototype is intended to validate.
Request an engineering review
Send the material, thickness, array file, critical dimensions, quantity and inspection method. Finalfoil will review the hole pattern, processing route, handling and documentation before quotation.